Programs & Examples On #Po

PO files are the format of the GNU gettext translation files.

How to get AIC from Conway–Maxwell-Poisson regression via COM-poisson package in R?

I figured out myself.

cmp calls ComputeBetasAndNuHat which returns a list which has objective as minusloglik

So I can change the function cmp to get this value.

Monitoring the Full Disclosure mailinglist

Two generic ways to do the same thing... I'm not aware of any specific open solutions to do this, but it'd be rather trivial to do.

You could write a daily or weekly cron/jenkins job to scrape the previous time period's email from the archive looking for your keyworkds/combinations. Sending a batch digest with what it finds, if anything.

But personally, I'd Setup a specific email account to subscribe to the various security lists you're interested in. Add a simple automated script to parse the new emails for various keywords or combinations of keywords, when it finds a match forward that email on to you/your team. Just be sure to keep the keywords list updated with new products you're using.

You could even do this with a gmail account and custom rules, which is what I currently do, but I have setup an internal inbox in the past with a simple python script to forward emails that were of interest.

I am receiving warning in Facebook Application using PHP SDK

You need to ensure that any code that modifies the HTTP headers is executed before the headers are sent. This includes statements like session_start(). The headers will be sent automatically when any HTML is output.

Your problem here is that you're sending the HTML ouput at the top of your page before you've executed any PHP at all.

Move the session_start() to the top of your document :

<?php    session_start(); ?> <html> <head> <title>PHP SDK</title> </head> <body> <?php require_once 'src/facebook.php';    // more PHP code here. 

PHP array value passes to next row

Change the checkboxes so that the name includes the index inside the brackets:

<input type="checkbox" class="checkbox_veh" id="checkbox_addveh<?php echo $i; ?>" <?php if ($vehicle_feature[$i]->check) echo "checked"; ?> name="feature[<?php echo $i; ?>]" value="<?php echo $vehicle_feature[$i]->id; ?>"> 

The checkboxes that aren't checked are never submitted. The boxes that are checked get submitted, but they get numbered consecutively from 0, and won't have the same indexes as the other corresponding input fields.

programming a servo thru a barometer

You could define a mapping of air pressure to servo angle, for example:

def calc_angle(pressure, min_p=1000, max_p=1200):     return 360 * ((pressure - min_p) / float(max_p - min_p))  angle = calc_angle(pressure) 

This will linearly convert pressure values between min_p and max_p to angles between 0 and 360 (you could include min_a and max_a to constrain the angle, too).

To pick a data structure, I wouldn't use a list but you could look up values in a dictionary:

d = {1000:0, 1001: 1.8, ...}  angle = d[pressure] 

but this would be rather time-consuming to type out!

Uninitialized Constant MessagesController

Your model is @Messages, change it to @message.

To change it like you should use migration:

def change   rename_table :old_table_name, :new_table_name end 

Of course do not create that file by hand but use rails generator:

rails g migration ChangeMessagesToMessage 

That will generate new file with proper timestamp in name in 'db dir. Then run:

rake db:migrate 

And your app should be fine since then.

Method Call Chaining; returning a pointer vs a reference?

Very interesting question.

I don't see any difference w.r.t safety or versatility, since you can do the same thing with pointer or reference. I also don't think there is any visible difference in performance since references are implemented by pointers.

But I think using reference is better because it is consistent with the standard library. For example, chaining in iostream is done by reference rather than pointer.

How can I tell if an algorithm is efficient?

Yes you can start with the Wikipedia article explaining the Big O notation, which in a nutshell is a way of describing the "efficiency" (upper bound of complexity) of different type of algorithms. Or you can look at an earlier answer where this is explained in simple english

Better solution without exluding fields from Binding

You should not use your domain models in your views. ViewModels are the correct way to do it.

You need to map your domain model's necessary fields to viewmodel and then use this viewmodel in your controllers. This way you will have the necessery abstraction in your application.

If you never heard of viewmodels, take a look at this.

Titlecase all entries into a form_for text field

You don't want to take care of normalizing your data in a view - what if the user changes the data that gets submitted? Instead you could take care of it in the model using the before_save (or the before_validation) callback. Here's an example of the relevant code for a model like yours:

class Place < ActiveRecord::Base   before_save do |place|     place.city = place.city.downcase.titleize     place.country = place.country.downcase.titleize   end end 

You can also check out the Ruby on Rails guide for more info.


To answer you question more directly, something like this would work:

<%= f.text_field :city, :value => (f.object.city ? f.object.city.titlecase : '') %>   

This just means if f.object.city exists, display the titlecase version of it, and if it doesn't display a blank string.

Undefined Symbols error when integrating Apptentive iOS SDK via Cocoapods

We have found that adding the Apptentive cocoa pod to an existing Xcode project may potentially not include some of our required frameworks.

Check your linker flags:

Target > Build Settings > Other Linker Flags 

You should see -lApptentiveConnect listed as a linker flag:

... -ObjC -lApptentiveConnect ... 

You should also see our required Frameworks listed:

  • Accelerate
  • CoreData
  • CoreText
  • CoreGraphics
  • CoreTelephony
  • Foundation
  • QuartzCore
  • StoreKit
  • SystemConfiguration
  • UIKit

    -ObjC -lApptentiveConnect -framework Accelerate -framework CoreData -framework CoreGraphics -framework CoreText -framework Foundation -framework QuartzCore -framework SystemConfiguration -framework UIKit -framework CoreTelephony -framework StoreKit  

How to do perspective fixing?

The simple solution is to just remap coordinates from the original to the final image, copying pixels from one coordinate space to the other, rounding off as necessary -- which may result in some pixels being copied several times adjacent to each other, and other pixels being skipped, depending on whether you're stretching or shrinking (or both) in either dimension. Make sure your copying iterates through the destination space, so all pixels are covered there even if they're painted more than once, rather than thru the source which may skip pixels in the output.

The better solution involves calculating the corresponding source coordinate without rounding, and then using its fractional position between pixels to compute an appropriate average of the (typically) four pixels surrounding that location. This is essentially a filtering operation, so you lose some resolution -- but the result looks a LOT better to the human eye; it does a much better job of retaining small details and avoids creating straight-line artifacts which humans find objectionable.

Note that the same basic approach can be used to remap flat images onto any other shape, including 3D surface mapping.

String index out of range: 4

You are using the wrong iteration counter, replace inp.charAt(i) with inp.charAt(j).

python variable NameError

Initialize tSize to

tSize = ""  

before your if block to be safe. Also in your else case, put tSize in quotes so it is a string not an int. Also also you are comparing strings to ints.

Pass PDO prepared statement to variables

You could do $stmt->queryString to obtain the SQL query used in the statement. If you want to save the entire $stmt variable (I can't see why), you could just copy it. It is an instance of PDOStatement so there is apparently no advantage in storing it.

Why my regexp for hyphenated words doesn't work?

A couple of things:

  1. Your regexes need to be anchored by separators* or you'll match partial words, as is the case now
  2. You're not using the proper syntax for a non-capturing group. It's (?: not (:?

If you address the first problem, you won't need groups at all.

*That is, a blank or beginning/end of string.

My eclipse won't open, i download the bundle pack it keeps saying error log

Make sure you have the prerequisite, a JVM (http://wiki.eclipse.org/Eclipse/Installation#Install_a_JVM) installed.

This will be a JRE and JDK package.

There are a number of sources which includes: http://www.oracle.com/technetwork/java/javase/downloads/index.html.

Hide Signs that Meteor.js was Used

The amount of hacks you would need to go through to completely hide the fact your site is built by Meteor.js is absolutely ridiculous. You would have to strip essentially all core functionality and just serve straight up html, completely defeating the purpose of using the framework anyway.

That being said, I suggest looking at buildwith.com

You enter a url, and it reveals a ton of information about a site. If you only need to "fool" engines like this, there may be simple solutions.

Implement specialization in ER diagram

So I assume your permissions table has a foreign key reference to admin_accounts table. If so because of referential integrity you will only be able to add permissions for account ids exsiting in the admin accounts table. Which also means that you wont be able to enter a user_account_id [assuming there are no duplicates!]

concat yesterdays date with a specific time

where date_dt = to_date(to_char(sysdate-1, 'YYYY-MM-DD') || ' 19:16:08', 'YYYY-MM-DD HH24:MI:SS') 

should work.

Comparing a variable with a string python not working when redirecting from bash script

When you read() the file, you may get a newline character '\n' in your string. Try either

if UserInput.strip() == 'List contents': 

or

if 'List contents' in UserInput: 

Also note that your second file open could also use with:

with open('/Users/.../USER_INPUT.txt', 'w+') as UserInputFile:     if UserInput.strip() == 'List contents': # or if s in f:         UserInputFile.write("ls")     else:         print "Didn't work" 

Accessing AppDelegate from framework?

If you're creating a framework the whole idea is to make it portable. Tying a framework to the app delegate defeats the purpose of building a framework. What is it you need the app delegate for?

Xml Parsing in C#

First add an Enrty and Category class:

public class Entry {     public string Id { get; set; }     public string Title { get; set; }     public string Updated { get; set; }     public string Summary { get; set; }     public string GPoint { get; set; }     public string GElev { get; set; }     public List<string> Categories { get; set; } }  public class Category {     public string Label { get; set; }     public string Term { get; set; } } 

Then use LINQ to XML

XDocument xDoc = XDocument.Load("path");          List<Entry> entries = (from x in xDoc.Descendants("entry")             select new Entry()             {                 Id = (string) x.Element("id"),                 Title = (string)x.Element("title"),                 Updated = (string)x.Element("updated"),                 Summary = (string)x.Element("summary"),                 GPoint = (string)x.Element("georss:point"),                 GElev = (string)x.Element("georss:elev"),                 Categories = (from c in x.Elements("category")                                   select new Category                                   {                                       Label = (string)c.Attribute("label"),                                       Term = (string)c.Attribute("term")                                   }).ToList();             }).ToList(); 

Instantiating a generic type

You cannot do new T() due to type erasure. The default constructor can only be

public Navigation() {     this("", "", null); } 

​ You can create other constructors to provide default values for trigger and description. You need an concrete object of T.

Does the target directory for a git clone have to match the repo name?

Yes, it is possible:

git clone https://github.com/pitosalas/st3_packages Packages 

You can specify the local root directory when using git clone.

<directory> 

The name of a new directory to clone into.
The "humanish" part of the source repository is used if no directory is explicitly given (repo for /path/to/repo.git and foo for host.xz:foo/.git).
Cloning into an existing directory is only allowed if the directory is empty.


As Chris comments, you can then rename that top directory.
Git only cares about the .git within said top folder, which you can get with various commands:

git rev-parse --show-toplevel git rev-parse --git-dir 

OS X Sprite Kit Game Optimal Default Window Size

You should target the smallest, not the largest, supported pixel resolution by the devices your app can run on.

Say if there's an actual Mac computer that can run OS X 10.9 and has a native screen resolution of only 1280x720 then that's the resolution you should focus on. Any higher and your game won't correctly run on this device and you could as well remove that device from your supported devices list.

You can rely on upscaling to match larger screen sizes, but you can't rely on downscaling to preserve possibly important image details such as text or smaller game objects.

The next most important step is to pick a fitting aspect ratio, be it 4:3 or 16:9 or 16:10, that ideally is the native aspect ratio on most of the supported devices. Make sure your game only scales to fit on devices with a different aspect ratio.

You could scale to fill but then you must ensure that on all devices the cropped areas will not negatively impact gameplay or the use of the app in general (ie text or buttons outside the visible screen area). This will be harder to test as you'd actually have to have one of those devices or create a custom build that crops the view accordingly.

Alternatively you can design multiple versions of your game for specific and very common screen resolutions to provide the best game experience from 13" through 27" displays. Optimized designs for iMac (desktop) and a Macbook (notebook) devices make the most sense, it'll be harder to justify making optimized versions for 13" and 15" plus 21" and 27" screens.

But of course this depends a lot on the game. For example a tile-based world game could simply provide a larger viewing area onto the world on larger screen resolutions rather than scaling the view up. Provided that this does not alter gameplay, like giving the player an unfair advantage (specifically in multiplayer).

You should provide @2x images for the Retina Macbook Pro and future Retina Macs.

How to create a showdown.js markdown extension

In your last block you have a comma after 'lang', followed immediately with a function. This is not valid json.

EDIT

It appears that the readme was incorrect. I had to to pass an array with the string 'twitter'.

var converter = new Showdown.converter({extensions: ['twitter']}); converter.makeHtml('whatever @meandave2020'); // output "<p>whatever <a href="http://twitter.com/meandave2020">@meandave2020</a></p>" 

I submitted a pull request to update this.

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

String method cannot be found in a main class method

It seem like your Resort method doesn't declare a compareTo method. This method typically belongs to the Comparable interface. Make sure your class implements it.

Additionally, the compareTo method is typically implemented as accepting an argument of the same type as the object the method gets invoked on. As such, you shouldn't be passing a String argument, but rather a Resort.

Alternatively, you can compare the names of the resorts. For example

if (resortList[mid].getResortName().compareTo(resortName)>0)  

Parameter binding on left joins with array in Laravel Query Builder

You don't have to bind parameters if you use query builder or eloquent ORM. However, if you use DB::raw(), ensure that you binding the parameters.

Try the following:

$array = array(1,2,3);       $query = DB::table('offers');             $query->select('id', 'business_id', 'address_id', 'title', 'details', 'value', 'total_available', 'start_date', 'end_date', 'terms', 'type', 'coupon_code', 'is_barcode_available', 'is_exclusive', 'userinformations_id', 'is_used');             $query->leftJoin('user_offer_collection', function ($join) use ($array)             {                 $join->on('user_offer_collection.offers_id', '=', 'offers.id')                       ->whereIn('user_offer_collection.user_id', $array);             });       $query->get(); 

Setting default checkbox value in Objective-C?

Documentation on UISwitch says:

[mySwitch setOn:NO]; 

In Interface Builder, select your switch and in the Attributes inspector you'll find State which can be set to on or off.

Highlight Anchor Links when user manually scrolls?

You can use Jquery's on method and listen for the scroll event.

Generating a list of pages (not posts) without the index file

I have never used jekyll, but it's main page says that it uses Liquid, and according to their docs, I think the following should work:

<ul> {% for page in site.pages %}     {% if page.title != 'index' %}     <li><div class="drvce"><a href="{{ page.url }}">{{ page.title }}</a></div></li>     {% endif %} {% endfor %} </ul> 

Warp \ bend effect on a UIView?

What you show looks like a mesh warp. That would be straightforward using OpenGL, but "straightforward OpenGL" is like straightforward rocket science.

I wrote an iOS app for my company called Face Dancerthat's able to do 60 fps mesh warp animations of video from the built-in camera using OpenGL, but it was a lot of work. (It does funhouse mirror type changes to faces - think "fat booth" live, plus lots of other effects.)

Are all Spring Framework Java Configuration injection examples buggy?

In your test, you are comparing the two TestParent beans, not the single TestedChild bean.

Also, Spring proxies your @Configuration class so that when you call one of the @Bean annotated methods, it caches the result and always returns the same object on future calls.

See here:

Use NSInteger as array index

According to the error message, you declared myLoc as a pointer to an NSInteger (NSInteger *myLoc) rather than an actual NSInteger (NSInteger myLoc). It needs to be the latter.

I need to know how to get my program to output the word i typed in and also the new rearranged word using a 2D array

  1. What exactly doesn't work?
  2. Why are you using a 2d array?
  3. If you must use a 2d array:

    int numOfPairs = 10;  String[][] array = new String[numOfPairs][2]; for(int i = 0; i < array.length; i++){     for(int j = 0; j < array[i].length; j++){         array[i] = new String[2];         array[i][0] = "original word";         array[i][1] = "rearranged word";     }    } 

Does this give you a hint?

Is it possible to change the content HTML5 alert messages?

You can use customValidity

$(function(){     var elements = document.getElementsByTagName("input");     for (var i = 0; i < elements.length; i++) {         elements[i].oninvalid = function(e) {             e.target.setCustomValidity("This can't be left blank!");         };     } }); 

I think that will work on at least Chrome and FF, I'm not sure about other browsers

is it possible to add colors to python output?

being overwhelmed by being VERY NEW to python i missed some very simple and useful commands given here: Print in terminal with colors using Python? -

eventually decided to use CLINT as an answer that was given there by great and smart people

Read input from a JOptionPane.showInputDialog box

Your problem is that, if the user clicks cancel, operationType is null and thus throws a NullPointerException. I would suggest that you move

if (operationType.equalsIgnoreCase("Q")) 

to the beginning of the group of if statements, and then change it to

if(operationType==null||operationType.equalsIgnoreCase("Q")). 

This will make the program exit just as if the user had selected the quit option when the cancel button is pushed.

Then, change all the rest of the ifs to else ifs. This way, once the program sees whether or not the input is null, it doesn't try to call anything else on operationType. This has the added benefit of making it more efficient - once the program sees that the input is one of the options, it won't bother checking it against the rest of them.

Cannot retrieve string(s) from preferences (settings)

All your exercise conditionals are separate and the else is only tied to the last if statement. Use else if to bind them all together in the way I believe you intend.

strange error in my Animation Drawable

Looks like whatever is in your Animation Drawable definition is too much memory to decode and sequence. The idea is that it loads up all the items and make them in an array and swaps them in and out of the scene according to the timing specified for each frame.

If this all can't fit into memory, it's probably better to either do this on your own with some sort of handler or better yet just encode a movie with the specified frames at the corresponding images and play the animation through a video codec.

Two Page Login with Spring Security 3.2.x

There should be three pages here:

  1. Initial login page with a form that asks for your username, but not your password.
  2. You didn't mention this one, but I'd check whether the client computer is recognized, and if not, then challenge the user with either a CAPTCHA or else a security question. Otherwise the phishing site can simply use the tendered username to query the real site for the security image, which defeats the purpose of having a security image. (A security question is probably better here since with a CAPTCHA the attacker could have humans sitting there answering the CAPTCHAs to get at the security images. Depends how paranoid you want to be.)
  3. A page after that that displays the security image and asks for the password.

I don't see this short, linear flow being sufficiently complex to warrant using Spring Web Flow.

I would just use straight Spring Web MVC for steps 1 and 2. I wouldn't use Spring Security for the initial login form, because Spring Security's login form expects a password and a login processing URL. Similarly, Spring Security doesn't provide special support for CAPTCHAs or security questions, so you can just use Spring Web MVC once again.

You can handle step 3 using Spring Security, since now you have a username and a password. The form login page should display the security image, and it should include the user-provided username as a hidden form field to make Spring Security happy when the user submits the login form. The only way to get to step 3 is to have a successful POST submission on step 1 (and 2 if applicable).

Hadoop MapReduce: Strange Result when Storing Previous Value in Memory in a Reduce Class (Java)

It is very inefficient to store all values in memory, so the objects are reused and loaded one at a time. See this other SO question for a good explanation. Summary:

[...] when looping through the Iterable value list, each Object instance is re-used, so it only keeps one instance around at a given time.

javascript, for loop defines a dynamic variable name

You cannot create different "variable names" but you can create different object properties. There are many ways to do whatever it is you're actually trying to accomplish. In your case I would just do

for (var i = myArray.length - 1; i >= 0; i--) {    console.log(eval(myArray[i])); }; 

More generally you can create object properties dynamically, which is the type of flexibility you're thinking of.

var result = {}; for (var i = myArray.length - 1; i >= 0; i--) {     result[myArray[i]] = eval(myArray[i]);   }; 

I'm being a little handwavey since I don't actually understand language theory, but in pure Javascript (including Node) references (i.e. variable names) are happening at a higher level than at runtime. More like at the call stack; you certainly can't manufacture them in your code like you produce objects or arrays. Browsers do actually let you do this anyway though it's terrible practice, via

window['myVarName'] = 'namingCollisionsAreFun';  

(per comment)

How can compare-and-swap be used for a wait-free mutual exclusion for any shared data structure?

The linked list holds operations on the shared data structure.

For example, if I have a stack, it will be manipulated with pushes and pops. The linked list would be a set of pushes and pops on the pseudo-shared stack. Each thread sharing that stack will actually have a local copy, and to get to the current shared state, it'll walk the linked list of operations, and apply each operation in order to its local copy of the stack. When it reaches the end of the linked list, its local copy holds the current state (though, of course, it's subject to becoming stale at any time).

In the traditional model, you'd have some sort of locks around each push and pop. Each thread would wait to obtain a lock, then do a push or pop, then release the lock.

In this model, each thread has a local snapshot of the stack, which it keeps synchronized with other threads' view of the stack by applying the operations in the linked list. When it wants to manipulate the stack, it doesn't try to manipulate it directly at all. Instead, it simply adds its push or pop operation to the linked list, so all the other threads can/will see that operation and they can all stay in sync. Then, of course, it applies the operations in the linked list, and when (for example) there's a pop it checks which thread asked for the pop. It uses the popped item if and only if it's the thread that requested this particular pop.

How is VIP swapping + CNAMEs better than IP swapping + A records?

A VIP swap is an internal change to Azure's routers/load balancers, not an external DNS change. They're just routing traffic to go from one internal [set of] server[s] to another instead. Therefore the DNS info for mysite.cloudapp.net doesn't change at all. Therefore the change for people accessing via the IP bound to mysite.cloudapp.net (and CNAME'd by you) will see the change as soon as the VIP swap is complete.

Querying date field in MongoDB with Mongoose

{ "date" : "1000000" } in your Mongo doc seems suspect. Since it's a number, it should be { date : 1000000 }

It's probably a type mismatch. Try post.findOne({date: "1000000"}, callback) and if that works, you have a typing issue.

Uploading into folder in FTP?

The folder is part of the URL you set when you create request: "ftp://www.contoso.com/test.htm". If you use "ftp://www.contoso.com/wibble/test.htm" then the file will be uploaded to a folder named wibble.

You may need to first use a request with Method = WebRequestMethods.Ftp.MakeDirectory to make the wibble folder if it doesn't already exist.

Speech input for visually impaired users without the need to tap the screen

The only way to get the iOS dictation is to sign up yourself through Nuance: http://dragonmobile.nuancemobiledeveloper.com/ - it's expensive, because it's the best. Presumably, Apple's contract prevents them from exposing an API.

The built in iOS accessibility features allow immobilized users to access dictation (and other keyboard buttons) through tools like VoiceOver and Assistive Touch. It may not be worth reinventing this if your users might be familiar with these tools.

Call japplet from jframe

First of all, Applets are designed to be run from within the context of a browser (or applet viewer), they're not really designed to be added into other containers.

Technically, you can add a applet to a frame like any other component, but personally, I wouldn't. The applet is expecting a lot more information to be available to it in order to allow it to work fully.

Instead, I would move all of the "application" content to a separate component, like a JPanel for example and simply move this between the applet or frame as required...

ps- You can use f.setLocationRelativeTo(null) to center the window on the screen ;)

Updated

You need to go back to basics. Unless you absolutely must have one, avoid applets until you understand the basics of Swing, case in point...

Within the constructor of GalzyTable2 you are doing...

JApplet app = new JApplet(); add(app); app.init(); app.start(); 

...Why are you adding another applet to an applet??

Case in point...

Within the main method, you are trying to add the instance of JFrame to itself...

f.getContentPane().add(f, button2); 

Instead, create yourself a class that extends from something like JPanel, add your UI logical to this, using compound components if required.

Then, add this panel to whatever top level container you need.

Take the time to read through Creating a GUI with Swing

Updated with example

import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.event.ActionEvent; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException;  public class GalaxyTable2 extends JPanel {      private static final int PREF_W = 700;     private static final int PREF_H = 600;      String[] columnNames                     = {"Phone Name", "Brief Description", "Picture", "price",                         "Buy"};  // Create image icons     ImageIcon Image1 = new ImageIcon(                     getClass().getResource("s1.png"));     ImageIcon Image2 = new ImageIcon(                     getClass().getResource("s2.png"));     ImageIcon Image3 = new ImageIcon(                     getClass().getResource("s3.png"));     ImageIcon Image4 = new ImageIcon(                     getClass().getResource("s4.png"));     ImageIcon Image5 = new ImageIcon(                     getClass().getResource("note.png"));     ImageIcon Image6 = new ImageIcon(                     getClass().getResource("note2.png"));     ImageIcon Image7 = new ImageIcon(                     getClass().getResource("note3.png"));      Object[][] rowData = {         {"Galaxy S", "3G Support,CPU 1GHz",             Image1, 120, false},         {"Galaxy S II", "3G Support,CPU 1.2GHz",             Image2, 170, false},         {"Galaxy S III", "3G Support,CPU 1.4GHz",             Image3, 205, false},         {"Galaxy S4", "4G Support,CPU 1.6GHz",             Image4, 230, false},         {"Galaxy Note", "4G Support,CPU 1.4GHz",             Image5, 190, false},         {"Galaxy Note2 II", "4G Support,CPU 1.6GHz",             Image6, 190, false},         {"Galaxy Note 3", "4G Support,CPU 2.3GHz",             Image7, 260, false},};      MyTable ss = new MyTable(                     rowData, columnNames);      // Create a table     JTable jTable1 = new JTable(ss);      public GalaxyTable2() {         jTable1.setRowHeight(70);          add(new JScrollPane(jTable1),                         BorderLayout.CENTER);          JPanel buttons = new JPanel();          JButton button = new JButton("Home");         buttons.add(button);         JButton button2 = new JButton("Confirm");         buttons.add(button2);          add(buttons, BorderLayout.SOUTH);     }      @Override      public Dimension getPreferredSize() {         return new Dimension(PREF_W, PREF_H);     }      public void actionPerformed(ActionEvent e) {         new AMainFrame7().setVisible(true);     }      public static void main(String[] args) {          EventQueue.invokeLater(new Runnable() {             @Override             public void run() {                 try {                     UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());                 } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {                     ex.printStackTrace();                 }                  JFrame frame = new JFrame("Testing");                 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);                 frame.add(new GalaxyTable2());                 frame.pack();                 frame.setLocationRelativeTo(null);                 frame.setVisible(true);             }         });     } } 

You also seem to have a lack of understanding about how to use layout managers.

Take the time to read through Creating a GUI with Swing and Laying components out in a container

FragmentActivity to Fragment

first of all;

a Fragment must be inside a FragmentActivity, that's the first rule,

a FragmentActivity is quite similar to a standart Activity that you already know, besides having some Fragment oriented methods

second thing about Fragments, is that there is one important method you MUST call, wich is onCreateView, where you inflate your layout, think of it as the setContentLayout

here is an example:

    @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     mView       = inflater.inflate(R.layout.fragment_layout, container, false);       return mView; } 

and continu your work based on that mView, so to find a View by id, call mView.findViewById(..);


for the FragmentActivity part:

the xml part "must" have a FrameLayout in order to inflate a fragment in it

        <FrameLayout             android:id="@+id/content_frame"             android:layout_width="match_parent"             android:layout_height="match_parent"  >         </FrameLayout> 

as for the inflation part

getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new YOUR_FRAGMENT, "TAG").commit();


begin with these, as there is tons of other stuf you must know about fragments and fragment activities, start of by reading something about it (like life cycle) at the android developer site

RegisterStartupScript from code behind not working when Update Panel is used

You need to use ScriptManager.RegisterStartupScript for Ajax.

protected void ButtonPP_Click(object sender, EventArgs e) {     if (radioBtnACO.SelectedIndex < 0)     {         string csname1 = "PopupScript";          var cstext1 = new StringBuilder();         cstext1.Append("alert('Please Select Criteria!')");          ScriptManager.RegisterStartupScript(this, GetType(), csname1,             cstext1.ToString(), true);     } } 

Real time face detection OpenCV, Python

Your line:

img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) 

will draw a rectangle in the image, but the return value will be None, so img changes to None and cannot be drawn.

Try

cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) 

500 Error on AppHarbor but downloaded build works on my machine

Just a wild guess: (not much to go on) but I have had similar problems when, for example, I was using the IIS rewrite module on my local machine (and it worked fine), but when I uploaded to a host that did not have that add-on module installed, I would get a 500 error with very little to go on - sounds similar. It drove me crazy trying to find it.

So make sure whatever options/addons that you might have and be using locally in IIS are also installed on the host.

Similarly, make sure you understand everything that is being referenced/used in your web.config - that is likely the problem area.

Laravel 4 with Sentry 2 add user to a group on Registration

Somehow, where you are using Sentry, you're not using its Facade, but the class itself. When you call a class through a Facade you're not really using statics, it's just looks like you are.

Do you have this:

use Cartalyst\Sentry\Sentry; 

In your code?

Ok, but if this line is working for you:

$user = $this->sentry->register(array(     'username' => e($data['username']),     'email' => e($data['email']),      'password' => e($data['password'])     )); 

So you already have it instantiated and you can surely do:

$adminGroup = $this->sentry->findGroupById(5); 

Rails 2.3.4 Persisting Model on Validation Failure

In your controller, render the new action from your create action if validation fails, with an instance variable, @car populated from the user input (i.e., the params hash). Then, in your view, add a logic check (either an if block around the form or a ternary on the helpers, your choice) that automatically sets the value of the form fields to the params values passed in to @car if car exists. That way, the form will be blank on first visit and in theory only be populated on re-render in the case of error. In any case, they will not be populated unless @car is set.

Is it possible to execute multiple _addItem calls asynchronously using Google Analytics?

From the docs:

_trackTrans() Sends both the transaction and item data to the Google Analytics server. This method should be called after _trackPageview(), and used in conjunction with the _addItem() and addTrans() methods. It should be called after items and transaction elements have been set up.

So, according to the docs, the items get sent when you call trackTrans(). Until you do, you can add items, but the transaction will not be sent.

Edit: Further reading led me here:

http://www.analyticsmarket.com/blog/edit-ecommerce-data

Where it clearly says you can start another transaction with an existing ID. When you commit it, the new items you listed will be added to that transaction.

php & mysql query not echoing in html with tags?

You need to append your variables to the echoed string. For example:

echo 'This is a string '.$PHPvariable.' and this is more string'; 

Comparing two joda DateTime instances

DateTime inherits its equals method from AbstractInstant. It is implemented as such

public boolean equals(Object readableInstant) {     // must be to fulfil ReadableInstant contract     if (this == readableInstant) {         return true;     }     if (readableInstant instanceof ReadableInstant == false) {         return false;     }     ReadableInstant otherInstant = (ReadableInstant) readableInstant;     return         getMillis() == otherInstant.getMillis() &&         FieldUtils.equals(getChronology(), otherInstant.getChronology()); } 

Notice the last line comparing chronology. It's possible your instances' chronologies are different.

xlrd.biffh.XLRDError: Excel xlsx file; not supported

The previous version, xlrd 1.2.0, may appear to work, but it could also expose you to potential security vulnerabilities. With that warning out of the way, if you still want to give it a go, type the following command:

pip install xlrd==1.2.0

Error: Node Sass version 5.0.0 is incompatible with ^4.0.0

If the error is

Error: Node Sass version 5.0.0 is incompatible with ^4.0.0

Step1: stop the server

Step2: run commands are npm uninstall node-sass

Step3: check node-sass in package.json if node-sass is available in the file then again run Step2.

Step4: npm install [email protected] <=== run command

Step5: wait until the command successfully runs.

Step6: start-server using npm start

Target class controller does not exist - Laravel 8

  • Yes in laravel 8 this error is occur..
  • After try many solutions I got these perfect solution
  • Just follow the steps...

CASE - 1

We can change in api.php and in web.php files like below..
The current way we write syntax is

Route::get('login', 'LoginController@login');

should be changed to

Route::get('login', [LoginController::class, 'login']);

CASE - 2

  1. First go to the file: app > Providers > RouteServiceProvider.php
  2. In that file replace the line
    protected $namespace = null; with protected $namespace = 'App\Http\Controllers'; enter image description here
  3. Then After add line ->namespace($this->namespace) as shown in image..
    enter image description here

Xcode 12, building for iOS Simulator, but linking in object file built for iOS, for architecture arm64

After trying and searching different solutions, I think the most safest way is adding the following code at the end of the Podfile

post_install do |pi|
   pi.pods_project.targets.each do |t|
       t.build_configurations.each do |bc|
          bc.build_settings['ARCHS[sdk=iphonesimulator*]'] =  `uname -m`
       end
   end
end

This way you only override the iOS simulator's compiler architecture as your current cpu's architecture. Compared to others, this solution will also work on computers with Apple Silicon.

When adding a Javascript library, Chrome complains about a missing source map, why?

Try to see if it works in Incognito Mode. If it does, then it's a bug in recent Chrome. On my computer the following fix worked:

  1. Quit Chrome
  2. Delete your full Chrome cache folder
  3. Restart Chrome

error NG6002: Appears in the NgModule.imports of AppModule, but could not be resolved to an NgModule class

For me I was working under Ubuntu

The error disappeared if I use sudo with ng

sudo ng build
sudo ng serve

error TS1086: An accessor cannot be declared in an ambient context in Angular 9

I had this problem but didn't have a version conflict in my package.json.

My package-lock.json was somehow out of sync with package json though. Deleting and regenerating it worked for me.

TS1086: An accessor cannot be declared in ambient context

In my case downgrading @angular/animations worked, if you can afford to do that, run the command

npm i @angular/[email protected]

Or use another version that might work for you from the Versions tab here: https://www.npmjs.com/package/@angular/animations

Maven dependencies are failing with a 501 error

Effective January 15, 2020, The Central Repository no longer supports insecure communication over plain HTTP and requires that all requests to the repository are encrypted over HTTPS.

If you're receiving this error, then you need to replace all URL references to Maven Central with their canonical HTTPS counterparts.

(source)

We have made the following changes in my project's build.gradle:

Old:

repositories {
   maven { url "http://repo.maven.apache.org/maven2" }
}

New:

repositories {
   maven { url "https://repo.maven.apache.org/maven2" }
}

IntelliJ: Error:java: error: release version 5 not supported

Took me a while to aggregate an actual solution, but here's how to get rid of this compile error.

  1. Open IntelliJ preferences.

  2. Search for "compiler" (or something like "compi").

  3. Scroll down to Maven -->java compiler. In the right panel will be a list of modules and their associated java compile version "target bytecode version."

  4. Select a version >1.5. You may need to upgrade your jdk if one is not available.

enter image description here

Replace specific text with a redacted version using Python

You can do it using named-entity recognition (NER). It's fairly simple and there are out-of-the-shelf tools out there to do it, such as spaCy.

NER is an NLP task where a neural network (or other method) is trained to detect certain entities, such as names, places, dates and organizations.

Example:

Sponge Bob went to South beach, he payed a ticket of $200!
I know, Michael is a good person, he goes to McDonalds, but donates to charity at St. Louis street.

Returns:

NER with spacy

Just be aware that this is not 100%!

Here are a little snippet for you to try out:

import spacy

phrases = ['Sponge Bob went to South beach, he payed a ticket of $200!', 'I know, Michael is a good person, he goes to McDonalds, but donates to charity at St. Louis street.']
nlp = spacy.load('en')
for phrase in phrases:
   doc = nlp(phrase)
   replaced = ""
   for token in doc:
      if token in doc.ents:
         replaced+="XXXX "
      else:
         replaced+=token.text+" "

Read more here: https://spacy.io/usage/linguistic-features#named-entities

You could, instead of replacing with XXXX, replace based on the entity type, like:

if ent.label_ == "PERSON":
   replaced += "<PERSON> "

Then:

import re, random

personames = ["Jack", "Mike", "Bob", "Dylan"]

phrase = re.replace("<PERSON>", random.choice(personames), phrase)

Message: Trying to access array offset on value of type null

This happens because $cOTLdata is not null but the index 'char_data' does not exist. Previous versions of PHP may have been less strict on such mistakes and silently swallowed the error / notice while 7.4 does not do this anymore.

To check whether the index exists or not you can use isset():

isset($cOTLdata['char_data'])

Which means the line should look something like this:

$len = isset($cOTLdata['char_data']) ? count($cOTLdata['char_data']) : 0;

Note I switched the then and else cases of the ternary operator since === null is essentially what isset already does (but in the positive case).

Template not provided using create-react-app

I had same problem & i have installed "create-react-app" globally on my machine. There is error :

"A template was not provided. This is likely because you're using an outdated version of create-react-app. Please note that global installs of create-react-app are no longer supported."

Then i removed previous install by using this command.

npm uninstall -g create-react-app

Then install new react app.

npx create-react-app new-app

Array and string offset access syntax with curly braces is deprecated

It's really simple to fix the issue, however keep in mind that you should fork and commit your changes for each library you are using in their repositories to help others as well.

Let's say you have something like this in your code:

$str = "test";
echo($str{0});

since PHP 7.4 curly braces method to get individual characters inside a string has been deprecated, so change the above syntax into this:

$str = "test";
echo($str[0]);

Fixing the code in the question will look something like this:

public function getRecordID(string $zoneID, string $type = '', string $name = ''): string
{
    $records = $this->listRecords($zoneID, $type, $name);
    if (isset($records->result[0]->id)) {
        return $records->result[0]->id;
    }
    return false;
}

dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib

I was able to solve this by upgrading Python 3 via brew

brew upgrade python@3

@angular/material/index.d.ts' is not a module

import { MatDialogModule } from '@angular/material/dialog';
import { MatTableModule } from '@angular/material/table';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';
import { MatButtonModule } from '@angular/material/button';

Upgrade to python 3.8 using conda

You can update your python version to 3.8 in conda using the command

conda install -c anaconda python=3.8

as per https://anaconda.org/anaconda/python. Though not all packages support 3.8 yet, running

conda update --all

may resolve some dependency failures. You can also create a new environment called py38 using this command

conda create -n py38 python=3.8

Edit - note that the conda install option will potentially take a while to solve the environment, and if you try to abort this midway through you will lose your Python installation (usually this means it will resort to non-conda pre-installed system Python installation).

SyntaxError: Cannot use import statement outside a module

According to the official doc (https://nodejs.org/api/esm.html#esm_code_import_code_statements):

import statements are permitted only in ES modules. For similar functionality in CommonJS, see import().

To make Node treat your file as a ES module you need to (https://nodejs.org/api/esm.html#esm_enabling):

  • add "type": "module" to package.json
  • add "--experimental-modules" flag to the node call

What's the net::ERR_HTTP2_PROTOCOL_ERROR about?

In my case, it was WordPress that now requires PHP 7.4 and I was running 7.2.
As soon as I updated, the errors disappeared.

"Uncaught SyntaxError: Cannot use import statement outside a module" when importing ECMAScript 6

The error is triggered because the file you're linking to in your HTML file is the unbundled version of the file. To get the full bundled version you'll have to install it with npm:

npm install --save milsymbol

This downloads the full package to your node_modules folder.

You can then access the standalone minified JavaScript file at node_modules/milsymbol/dist/milsymbol.js

You can do this in any directory, and then just copy the below file to your /src directory.

How to fix "set SameSite cookie to none" warning?

>= PHP 7.3

setcookie('key', 'value', ['samesite' => 'None', 'secure' => true]);

< PHP 7.3

exploit the path
setcookie('key', 'value', time()+(7*24*3600), "/; SameSite=None; Secure");

Emitting javascript

echo "<script>document.cookie('key=value; SameSite=None; Secure');</script>";

Has been compiled by a more recent version of the Java Runtime (class file version 57.0)

This is a setting in IntelliJ IDEA ($JAVA_HOME and language level were set to 1.8):

File > Settings > Build, Execution, Deployment > Gradle > Gradle JVM

Select eg. Project SDK (corretto-1.8) (or any other compatible version).

Then delete the build directory and restart the IDE.

Why powershell does not run Angular commands?

Remove ng.ps1 from the directory C:\Users\%username%\AppData\Roaming\npm\ then try clearing the npm cache at C:\Users\%username%\AppData\Roaming\npm-cache\

Server Discovery And Monitoring engine is deprecated

It is simple , remove the code that you have used and use the below code :

const url = 'mongodb://localhost:27017';
var dbConn = mongodb.MongoClient.connect(url, {useUnifiedTopology: true});

Unable to allocate array with shape and data type

change the data type to another one which uses less memory works. For me, I change the data type to numpy.uint8:

data['label'] = data['label'].astype(np.uint8)

How to fix error "ERROR: Command errored out with exit status 1: python." when trying to install django-heroku using pip

You need to add the package containing the executable pg_config.

A prior answer should have details you need: pg_config executable not found

How to prevent Google Colab from disconnecting?

The most voted answer certainly works for me but it makes the Manage session window popping up again and again.
I've solved that by auto clicking the refresh button using browser console like below

function ClickRefresh(){
    console.log("Clicked on refresh button"); 
    document.querySelector("paper-icon-button").click()
}
setInterval(ClickRefresh, 60000)

Feel free to contribute more snippets for this at this gist https://gist.github.com/Subangkar/fd1ef276fd40dc374a7c80acc247613e

Element implicitly has an 'any' type because expression of type 'string' can't be used to index

This is what it worked for me. The tsconfig.json has an option noImplicitAny that it was set to true, I just simply set it to false and now I can access properties in objects using strings.

dotnet ef not found in .NET Core 3

if your using snap package dotnet-sdk on linux this can resolve by updating your ~.bashrc / etc. as follows:

#!/bin/bash
export DOTNET_ROOT=/snap/dotnet-sdk/current
export MSBuildSDKsPath=$DOTNET_ROOT/sdk/$(${DOTNET_ROOT}/dotnet --version)/Sdks
export PATH="${PATH}:${DOTNET_ROOT}"
export PATH="$PATH:$HOME/.dotnet/tools"

"Permission Denied" trying to run Python on Windows 10

Add the path of python folder in environmental variable and it will work

1.search environmental variable

2.look for system variable section and find variable named path in it

3.double click on path and add new path which directs towards python folder and that's it.

the python folder is usually in C:\Users["user name"]\AppData\Local\Programs\Python\Python39

Angular @ViewChild() error: Expected 2 arguments, but got 1

In Angular 8, ViewChild always takes 2 param, and second params always has static: true or static: false

You can try like this:

@ViewChild('nameInput', {static: false}) component

Also,the static: false is going to be the default fallback behaviour in Angular 9.

What are static false/true: So as a rule of thumb you can go for the following:

  • { static: true } needs to be set when you want to access the ViewChild in ngOnInit.

    { static: false } can only be accessed in ngAfterViewInit. This is also what you want to go for when you have a structural directive (i.e. *ngIf) on your element in your template.

Invalid hook call. Hooks can only be called inside of the body of a function component

My case.... SOLUTION in HOOKS

const [cep, setCep] = useState('');
const mounted = useRef(false);

useEffect(() => {
    if (mounted.current) {
        fetchAPI();
      } else {
        mounted.current = true;
      }
}, [cep]);

const setParams = (_cep) => {
    if (cep !== _cep || cep === '') {
        setCep(_cep);
    }
};

Typescript: No index signature with a parameter of type 'string' was found on type '{ "A": string; }

Solved similar issue by doing this:

export interface IItem extends Record<string, any> {
    itemId: string;
    price: number;
}

const item: IItem = { itemId: 'someId', price: 200 };
const fieldId = 'someid';

// gives you no errors and proper typing
item[fieldId]

Schema validation failed with the following errors: Data path ".builders['app-shell']" should have required property 'class'

I have to say, if you don't want to change anything in package.json file, try to update your Node.js version to latest. (currently 12.13.1 LTS)

Is it possible to opt-out of dark mode on iOS 13?

import UIKit

extension UIViewController {

    override open func awakeFromNib() {

        super.awakeFromNib()

        if #available(iOS 13.0, *) {

            overrideUserInterfaceStyle = .light

        }

    }
}

Make a VStack fill the width of the screen in SwiftUI

enter image description here

Login Page design using SwiftUI

import SwiftUI

struct ContentView: View {

    @State var email: String = "[email protected]"
    @State var password: String = ""
    @State static var labelTitle: String = ""


    var body: some View {
        VStack(alignment: .center){
            //Label
            Text("Login").font(.largeTitle).foregroundColor(.yellow).bold()
            //TextField
            TextField("Email", text: $email)
                .textContentType(.emailAddress)
                .foregroundColor(.blue)
                .frame(minHeight: 40)
                .background(RoundedRectangle(cornerRadius: 10).foregroundColor(Color.green))

            TextField("Password", text: $password) //Placeholder
                .textContentType(.newPassword)
                .frame(minHeight: 40)
                .foregroundColor(.blue) // Text color
                .background(RoundedRectangle(cornerRadius: 10).foregroundColor(Color.green))

            //Button
            Button(action: {

            }) {
                HStack {
                    Image(uiImage: UIImage(named: "Login")!)
                        .renderingMode(.original)
                        .font(.title)
                        .foregroundColor(.blue)
                    Text("Login")
                        .font(.title)
                        .foregroundColor(.white)
                }


                .font(.headline)
                .frame(minWidth: 0, maxWidth: .infinity)
                .background(LinearGradient(gradient: Gradient(colors: [Color("DarkGreen"), Color("LightGreen")]), startPoint: .leading, endPoint: .trailing))
                .cornerRadius(40)
                .padding(.horizontal, 20)

                .frame(width: 200, height: 50, alignment: .center)
            }
            Spacer()

        }.padding(10)

            .frame(minWidth: 0, idealWidth: .infinity, maxWidth: .infinity, minHeight: 0, idealHeight: .infinity, maxHeight: .infinity, alignment: .top)
            .background(Color.gray)

    }

}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

Access blocked by CORS policy: Response to preflight request doesn't pass access control check

You can just create the required CORS configuration as a bean. As per the code below this will allow all requests coming from any origin. This is good for development but insecure. Spring Docs

@Bean
WebMvcConfigurer corsConfigurer() {
    return new WebMvcConfigurer() {
        @Override
        void addCorsMappings(CorsRegistry registry) {
            registry.addMapping("/**")
                    .allowedOrigins("*")
        }
    }
}

How to style components using makeStyles and still have lifecycle methods in Material UI?

Hi instead of using hook API, you should use Higher-order component API as mentioned here

I'll modify the example in the documentation to suit your need for class component

import React from 'react';
import PropTypes from 'prop-types';
import { withStyles } from '@material-ui/styles';
import Button from '@material-ui/core/Button';

const styles = theme => ({
  root: {
    background: 'linear-gradient(45deg, #FE6B8B 30%, #FF8E53 90%)',
    border: 0,
    borderRadius: 3,
    boxShadow: '0 3px 5px 2px rgba(255, 105, 135, .3)',
    color: 'white',
    height: 48,
    padding: '0 30px',
  },
});

class HigherOrderComponentUsageExample extends React.Component {
  
  render(){
    const { classes } = this.props;
    return (
      <Button className={classes.root}>This component is passed to an HOC</Button>
      );
  }
}

HigherOrderComponentUsageExample.propTypes = {
  classes: PropTypes.object.isRequired,
};

export default withStyles(styles)(HigherOrderComponentUsageExample);

origin 'http://localhost:4200' has been blocked by CORS policy in Angular7

If your project is .net Core 3.1 API project.

update your Startup.cs in your .net core project to:

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }
    readonly string MyAllowSpecificOrigins = "_myAllowSpecificOrigins";
    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddCors(options =>
        {
            options.AddPolicy(MyAllowSpecificOrigins,
            builder =>
            {
                builder.WithOrigins("http://localhost:53135",
                                    "http://localhost:4200"
                                    )
                                    .AllowAnyHeader()
                                    .AllowAnyMethod();
            });
        });
        services.AddDbContext<CIVDataContext>(options =>
        options.UseSqlServer(Configuration.GetConnectionString("CIVDatabaseConnection")));
        services.AddControllers();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        app.UseCors(MyAllowSpecificOrigins);

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });

       
    }
}

Understanding esModuleInterop in tsconfig file

esModuleInterop generates the helpers outlined in the docs. Looking at the generated code, we can see exactly what these do:

//ts 
import React from 'react'
//js 
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
var react_1 = __importDefault(require("react"));

__importDefault: If the module is not an es module then what is returned by require becomes the default. This means that if you use default import on a commonjs module, the whole module is actually the default.

__importStar is best described in this PR:

TypeScript treats a namespace import (i.e. import * as foo from "foo") as equivalent to const foo = require("foo"). Things are simple here, but they don't work out if the primary object being imported is a primitive or a value with call/construct signatures. ECMAScript basically says a namespace record is a plain object.

Babel first requires in the module, and checks for a property named __esModule. If __esModule is set to true, then the behavior is the same as that of TypeScript, but otherwise, it synthesizes a namespace record where:

  1. All properties are plucked off of the require'd module and made available as named imports.
  2. The originally require'd module is made available as a default import.

So we get this:

// ts
import * as React from 'react'

// emitted js
var __importStar = (this && this.__importStar) || function (mod) {
    if (mod && mod.__esModule) return mod;
    var result = {};
    if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
    result["default"] = mod;
    return result;
};
Object.defineProperty(exports, "__esModule", { value: true });
var React = __importStar(require("react"));

allowSyntheticDefaultImports is the companion to all of this, setting this to false will not change the emitted helpers (both of them will still look the same). But it will raise a typescript error if you are using default import for a commonjs module. So this import React from 'react' will raise the error Module '".../node_modules/@types/react/index"' has no default export. if allowSyntheticDefaultImports is false.

Why am I getting Unknown error in line 1 of pom.xml?

Add <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version> in property tag

problem resolve

https://medium.com/@saannjaay/unknown-error-in-pom-xml-66fb2414991b

How to fix ReferenceError: primordials is not defined in node

I was getting this error on Windows 10. Turned out to be a corrupted roaming profile.

npm ERR! node v12.4.0
npm ERR! npm  v3.3.12

npm ERR! primordials is not defined
npm ERR!
npm ERR! If you need help, you may report this error at:
npm ERR!     <https://github.com/npm/npm/issues>

npm ERR! Please include the following file with any support request:

Deleting the C:\Users\{user}\AppData\Roaming\npm folder fixed my issue.

How to fix 'Object arrays cannot be loaded when allow_pickle=False' for imdb.load_data() function?

You can try changing the flag's value

np.load(training_image_names_array,allow_pickle=True)

Module 'tensorflow' has no attribute 'contrib'

This issue might be helpful for you, it explains how to achieve TPUStrategy, a popular functionality of tf.contrib in TF<2.0.

So, in TF 1.X you could do the following:

resolver = tf.contrib.cluster_resolver.TPUClusterResolver('grpc://' + os.environ['COLAB_TPU_ADDR'])
tf.contrib.distribute.initialize_tpu_system(resolver)
strategy = tf.contrib.distribute.TPUStrategy(resolver)

And in TF>2.0, where tf.contrib is deprecated, you achieve the same by:

tf.config.experimental_connect_to_host('grpc://' + os.environ['COLAB_TPU_ADDR'])
resolver = tf.distribute.cluster_resolver.TPUClusterResolver('grpc://' + os.environ['COLAB_TPU_ADDR'])
tf.tpu.experimental.initialize_tpu_system(resolver)
strategy = tf.distribute.experimental.TPUStrategy(resolver) 

How to fix missing dependency warning when using useEffect React Hook?

const [mount, setMount] = useState(false)
const fetchBusinesses = () => { 
   //function defination
}
useEffect(() => {
   if(!mount) {
      setMount(true);
      fetchBusinesses();
   }
},[fetchBusinesses]);

This is solution is pretty simple and you don't need to override es-lint warnings. Just maintain a flag to check whether component is mounted or not.

React Native Error: ENOSPC: System limit for number of file watchers reached

delete react node_modules

rm -r node_modules

yarn or npm install

yarn start or npm start

if error occurs use this method again

Is it possible to install Xcode 10.2 on High Sierra (10.13.6)?

Yes it's possible. Follow these steps:

  1. Download Xcode 10.2 via this link (you need to be signed in with your Apple Id): https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_10.2/Xcode_10.2.xip and install it
  2. Edit Xcode.app/Contents/Info.plist and change the Minimum System Version to 10.13.6
  3. Do the same for Xcode.app/Contents/Developer/Applications/Simulator.app/Contents/Info.plist (might require a restart of Xcode and/or Mac OS to make it open the simulator on run)
  4. Replace Xcode.app/Contents/Developer/usr/bin/xcodebuild with the one from 10.1 (or another version you have currently installed, such as 10.0).
  5. If there are problems with the simulator, reboot your Mac

Module not found: Error: Can't resolve 'core-js/es6'

Ended up to have a file named polyfill.js in projectpath\src\polyfill.js That file only contains this line: import 'core-js'; this polyfills not only es-6, but is the correct way to use core-js since version 3.0.0.

I added the polyfill.js to my webpack-file entry attribute like this:

entry: ['./src/main.scss', './src/polyfill.js', './src/main.jsx']

Works perfectly.

I also found some more information here : https://github.com/zloirock/core-js/issues/184

The library author (zloirock) claims:

ES6 changes behaviour almost all features added in ES5, so core-js/es6 entry point includes almost all of them. Also, as you wrote, it's required for fixing broken browser implementations.

(Quotation https://github.com/zloirock/core-js/issues/184 from zloirock)

So I think import 'core-js'; is just fine.

How to set value to form control in Reactive Forms in Angular

In Reactive Form, there are 2 primary solutions to update value(s) of form field(s).

setValue:

  • Initialize Model Structure in Constructor:

    this.newForm = this.formBuilder.group({  
       firstName: ['', [Validators.required, Validators.minLength(3), Validators.maxLength(8)]],
       lastName: ['', [Validators.required, Validators.minLength(3), Validators.maxLength(8)]]
    });
    
  • If you want to update all fields of form:

    this.newForm.setValue({
       firstName: 'abc',
       lastName: 'def'
    });
    
  • If you want to update specific field of form:

    this.newForm.controls.firstName.setValue('abc');
    

Note: It’s mandatory to provide complete model structure for all form field controls within the FormGroup. If you miss any property or subset collections, then it will throw an exception.

patchValue:

  • If you want to update some/ specific fields of form:

    this.newForm.patchValue({
       firstName: 'abc'
    });
    

Note: It’s not mandatory to provide model structure for all/ any form field controls within the FormGroup. If you miss any property or subset collections, then it will not throw any exception.

session not created: This version of ChromeDriver only supports Chrome version 74 error with ChromeDriver Chrome using Selenium

I got the same error when I am using robot framework (Selenium based framework) in a Docker instance. The reason was docker was using cached google-chrome-stable_current_amd64.deb for Chrome but it has installed latest chrome driver which was a later version.

Then I used below command and error resolved.

docker-compose build --no-cache

Hope this helps someone.

The POST method is not supported for this route. Supported methods: GET, HEAD. Laravel

mainly this type of error generate, 1.first check a code, in code, we define @csrf

<form method ="post" action={{url('project'')}}
   @csrf
   ...... 

2.when we define a wrong variable name, that time also happened this type of problem.

ex. if your database field name "xyz" and you use a "wxyz"

3.if our method is wrong in form,so plz check our method. ex. <form method="post">

Tensorflow 2.0 - AttributeError: module 'tensorflow' has no attribute 'Session'

For TF2.x, you can do like this.

import tensorflow as tf
with tf.compat.v1.Session() as sess:
    hello = tf.constant('hello world')
    print(sess.run(hello))

>>> b'hello world

react hooks useEffect() cleanup for only componentWillUnmount?

useEffect are isolated within its own scope and gets rendered accordingly. Image from https://reactjs.org/docs/hooks-custom.html

enter image description here

Jupyter Notebook not saving: '_xsrf' argument missing from post

This is the easiest way.

I did not need to open a new notebook. Instead, I reopened the tree, and reconnected the kernel. At some point I also restarted the kernel. – user650654 Oct 9 '19 at 0:17

How to use callback with useState hook in react

Another way to achieve this:

_x000D_
_x000D_
const [Name, setName] = useState({val:"", callback: null});_x000D_
React.useEffect(()=>{_x000D_
  console.log(Name)_x000D_
  const {callback} = Name;_x000D_
  callback && callback();_x000D_
}, [Name]);_x000D_
setName({val:'foo', callback: ()=>setName({val: 'then bar'})})
_x000D_
_x000D_
_x000D_

How can I solve the error 'TS2532: Object is possibly 'undefined'?

Edit / Update:

If you are using Typescript 3.7 or newer you can now also do:

    const data = change?.after?.data();

    if(!data) {
      console.error('No data here!');
       return null
    }

    const maxLen = 100;
    const msgLen = data.messages.length;
    const charLen = JSON.stringify(data).length;

    const batch = db.batch();

    if (charLen >= 10000 || msgLen >= maxLen) {

      // Always delete at least 1 message
      const deleteCount = msgLen - maxLen <= 0 ? 1 : msgLen - maxLen
      data.messages.splice(0, deleteCount);

      const ref = db.collection("chats").doc(change.after.id);

      batch.set(ref, data, { merge: true });

      return batch.commit();
    } else {
      return null;
    }

Original Response

Typescript is saying that change or data is possibly undefined (depending on what onUpdate returns).

So you should wrap it in a null/undefined check:

if(change && change.after && change.after.data){
    const data = change.after.data();

    const maxLen = 100;
    const msgLen = data.messages.length;
    const charLen = JSON.stringify(data).length;

    const batch = db.batch();

    if (charLen >= 10000 || msgLen >= maxLen) {

      // Always delete at least 1 message
      const deleteCount = msgLen - maxLen <= 0 ? 1 : msgLen - maxLen
      data.messages.splice(0, deleteCount);

      const ref = db.collection("chats").doc(change.after.id);

      batch.set(ref, data, { merge: true });

      return batch.commit();
    } else {
      return null;
    }
}

If you are 100% sure that your object is always defined then you can put this:

const data = change.after!.data();

The iOS Simulator deployment targets is set to 7.0, but the range of supported deployment target version for this platform is 8.0 to 12.1

Instead of specifying a deployment target in pod post install, you can delete the pod deployment target, which causes the deployment target to be inherited from the podfile platform.

You may need to run pod install for the effect to take place.

platform :ios, '12.0'

  post_install do |installer|
    installer.pods_project.targets.each do |target|
      target.build_configurations.each do |config|
        config.build_settings.delete 'IPHONEOS_DEPLOYMENT_TARGET'
      end
    end
  end

How to Install pip for python 3.7 on Ubuntu 18?

Install python pre-requisites

sudo apt update
sudo apt install build-essential zlib1g-dev libncurses5-dev libgdbm-dev libnss3-dev libssl-dev libreadline-dev libffi-dev wget

Install python 3.7 (from ppa repository)

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update
sudo apt install python3.7

Install pip3.7

sudo apt install python3-pip
python3.7 -m pip install pip

Create python and pip alternatives

sudo update-alternatives --install /usr/local/bin/python python /usr/bin/python3.7 10
sudo update-alternatives --install /usr/local/bin/pip pip /home/your_username/.local/bin/pip3.7 10

Make changes

source ~/.bashrc
python --version
pip --version

Flutter Countdown Timer

If all you need is a simple countdown timer, this is a good alternative instead of installing a package. Happy coding!

countDownTimer() async {
 int timerCount;
 for (int x = 5; x > 0; x--) {
   await Future.delayed(Duration(seconds: 1)).then((_) {
     setState(() {
       timerCount -= 1;
    });
  });
 }
}

Python: 'ModuleNotFoundError' when trying to import module from imported package

FIRST, if you want to be able to access man1.py from man1test.py AND manModules.py from man1.py, you need to properly setup your files as packages and modules.

Packages are a way of structuring Python’s module namespace by using “dotted module names”. For example, the module name A.B designates a submodule named B in a package named A.

...

When importing the package, Python searches through the directories on sys.path looking for the package subdirectory.

The __init__.py files are required to make Python treat the directories as containing packages; this is done to prevent directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path.

You need to set it up to something like this:

man
|- __init__.py
|- Mans
   |- __init__.py
   |- man1.py
|- MansTest
   |- __init.__.py
   |- SoftLib
      |- Soft
         |- __init__.py
         |- SoftWork
            |- __init__.py
            |- manModules.py
      |- Unittests
         |- __init__.py
         |- man1test.py

SECOND, for the "ModuleNotFoundError: No module named 'Soft'" error caused by from ...Mans import man1 in man1test.py, the documented solution to that is to add man1.py to sys.path since Mans is outside the MansTest package. See The Module Search Path from the Python documentation. But if you don't want to modify sys.path directly, you can also modify PYTHONPATH:

sys.path is initialized from these locations:

  • The directory containing the input script (or the current directory when no file is specified).
  • PYTHONPATH (a list of directory names, with the same syntax as the shell variable PATH).
  • The installation-dependent default.

THIRD, for from ...MansTest.SoftLib import Soft which you said "was to facilitate the aforementioned import statement in man1.py", that's now how imports work. If you want to import Soft.SoftLib in man1.py, you have to setup man1.py to find Soft.SoftLib and import it there directly.

With that said, here's how I got it to work.

man1.py:

from Soft.SoftWork.manModules import *
# no change to import statement but need to add Soft to PYTHONPATH

def foo():
    print("called foo in man1.py")
    print("foo call module1 from manModules: " + module1())

man1test.py

# no need for "from ...MansTest.SoftLib import Soft" to facilitate importing..
from ...Mans import man1

man1.foo()

manModules.py

def module1():
    return "module1 in manModules"

Terminal output:

$ python3 -m man.MansTest.Unittests.man1test
Traceback (most recent call last):
  ...
    from ...Mans import man1
  File "/temp/man/Mans/man1.py", line 2, in <module>
    from Soft.SoftWork.manModules import *
ModuleNotFoundError: No module named 'Soft'

$ PYTHONPATH=$PYTHONPATH:/temp/man/MansTest/SoftLib
$ export PYTHONPATH
$ echo $PYTHONPATH
:/temp/man/MansTest/SoftLib
$ python3 -m man.MansTest.Unittests.man1test
called foo in man1.py
foo called module1 from manModules: module1 in manModules 

As a suggestion, maybe re-think the purpose of those SoftLib files. Is it some sort of "bridge" between man1.py and man1test.py? The way your files are setup right now, I don't think it's going to work as you expect it to be. Also, it's a bit confusing for the code-under-test (man1.py) to be importing stuff from under the test folder (MansTest).

Typescript: Type X is missing the following properties from type Y length, pop, push, concat, and 26 more. [2740]

This error could also be because you are not subscribing to the Observable.

Example, instead of:

this.products = this.productService.getProducts();

do this:

   this.productService.getProducts().subscribe({
    next: products=>this.products = products,
    error: err=>this.errorMessage = err
   });

How do I prevent Conda from activating the base environment by default?

To disable auto activation of conda base environment in terminal:

conda config --set auto_activate_base false

To activate conda base environment:

conda activate

Gradle: Could not determine java version from '11.0.2'

I ran into the same issue in Ubuntu 18.04.3 LTS. In my case, apt installed gradle version 4.4.1. The already-install java version was 11.0.4

The build message I got was

Could not determine java version from '11.0.4'.

At the time, most of the online docs referenced gradle version 5.6, so I did the following:

sudo add-apt-repository ppa:cwchien/gradle
sudo apt update
sudo apt upgrade gradle

Then I repeated the project initialiation (using "gradle init" with the defaults). After that, "./gradlew build" worked correctly.

I later read a comment regarding a change in format of the output from "java --version" that caused gradle to break, which was fixed in a later version of gradle.

"Failed to install the following Android SDK packages as some licences have not been accepted" error

Tried this on Android Studio and it worked for me:

Tools > SDK Manager (Make sure to check Show Packages below)

SDK Platforms > Show Packages > Android - 28 SDK Platforms > Show Packages > Android - 28

SDK Tools > Show Packages > 28.0.3 SDK Tools > Show Packages > 28.0.3

Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"?

Or download composer.phar from site: "https://getcomposer.org/download/" (manual download), and use command:

php composer.phar require your/package

React Hooks useState() with Object

You can pass new value like this

  setExampleState({...exampleState,  masterField2: {
        fieldOne: "c",
        fieldTwo: {
           fieldTwoOne: "d",
           fieldTwoTwo: "e"
           }
        },
   }})

Error: Java: invalid target release: 11 - IntelliJ IDEA

2021 Jan.12th

the whole point for me is to explicitly specify the version as java 11 in my pom.xml, and I solved the problem by taking the following steps.

  1. open terminal and input: java -version, then i got 1.8, and i went to .bash_profile to switch the java version to 11.2 as i have multiple java version installed. please remember "restart" your terminal and check your java version again to confirm switch is successful.

  2. Then i went to File -> Project Structure to make sure my IntelliJ using the same version as my env, which is 11.2.

  3. RESTART your Intellij, mvn clean install, solved, hope this could help someone with this issue, thanks.

Requests (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.") Error in PyCharm requesting website

Windows Users need to set below paths:

  • ..\Anaconda3
  • ..\Anaconda3\scripts
  • ..\Anaconda3\Library\bin

Per user:

  1. Open Environment variable
  2. Click User Variable
  3. Close command prompt if already open and reopen it

System wide (requires restart):

  1. Open Environment variable
  2. Click System Variable
  3. Restart Windows

How to fix 'Unchecked runtime.lastError: The message port closed before a response was received' chrome issue?

Looks like the NoCoffee Vision Simulator extension for Chrome will also cause this error. Just adding it as a prospective cause for people looking in their own instance.

useState set method not reflecting change immediately

useEffect has its own state/lifecycle, it will not update until you pass a function in parameters or effect destroyed.

object and array spread or rest will not work inside useEffect.

React.useEffect(() => {
    console.log("effect");
    (async () => {
        try {
            let result = await fetch("/query/countries");
            const res = await result.json();
            let result1 = await fetch("/query/projects");
            const res1 = await result1.json();
            let result11 = await fetch("/query/regions");
            const res11 = await result11.json();
            setData({
                countries: res,
                projects: res1,
                regions: res11
            });
        } catch {}
    })(data)
}, [setData])
# or use this
useEffect(() => {
    (async () => {
        try {
            await Promise.all([
                fetch("/query/countries").then((response) => response.json()),
                fetch("/query/projects").then((response) => response.json()),
                fetch("/query/regions").then((response) => response.json())
            ]).then(([country, project, region]) => {
                // console.log(country, project, region);
                setData({
                    countries: country,
                    projects: project,
                    regions: region
                });
            })
        } catch {
            console.log("data fetch error")
        }
    })()
}, [setData]);

WARNING in budgets, maximum exceeded for initial

Open angular.json file and find budgets keyword.

It should look like:

    "budgets": [
       {
          "type": "initial",
          "maximumWarning": "2mb",
          "maximumError": "5mb"
       }
    ]

As you’ve probably guessed you can increase the maximumWarning value to prevent this warning, i.e.:

    "budgets": [
       {
          "type": "initial",
          "maximumWarning": "4mb", <===
          "maximumError": "5mb"
       }
    ]

What does budgets mean?

A performance budget is a group of limits to certain values that affect site performance, that may not be exceeded in the design and development of any web project.

In our case budget is the limit for bundle sizes.

See also:

Git fatal: protocol 'https' is not supported

I encountered the same problem after freshly installing git on Windows 10 and running it for the first time. Restarting the bash window solved the problem.

Can't perform a React state update on an unmounted component

The solution from @ford04 didn't worked to me and specially if you need to use the isMounted in multiple places (multiple useEffect for instance), it's recommended to useRef, as bellow:

  1. Essential packages
"dependencies": 
{
  "react": "17.0.1",
}
"devDependencies": { 
  "typescript": "4.1.5",
}

  1. My Hook Component
export const SubscriptionsView: React.FC = () => {
  const [data, setData] = useState<Subscription[]>();
  const isMounted = React.useRef(true);

  React.useEffect(() => {
    if (isMounted.current) {
      // fetch data
      // setData (fetch result)

      return () => {
        isMounted.current = false;
      };
    }
  }
});

UnhandledPromiseRejectionWarning: This error originated either by throwing inside of an async function without a catch block

I resolve the problem. It's very simple . if do you checking care the problem may be because the auxiliar variable has whitespace. Why ? I don't know but yus must use the trim() method and will resolve the problem

Pylint "unresolved import" error in Visual Studio Code

If someone happens to be as moronic as me, the following worked.

Old folder structure:

awesome_code.py
__init__.py
    src/
        __init__.py
        stuff1.py
        stuff2.py

New structure:

awesome_code.py
    src/
        __init__.py
        stuff1.py
        stuff2.py

React hooks useState Array

The accepted answer shows the correct way to setState but it does not lead to a well functioning select box.

import React, { useState } from "react"; 
import ReactDOM from "react-dom";

const initialValue = { id: 0,value: " --- Select a State ---" };

const options = [
    { id: 1, value: "Alabama" },
    { id: 2, value: "Georgia" },
    { id: 3, value: "Tennessee" }
];

const StateSelector = () => {   
   const [ selected, setSelected ] = useState(initialValue);  

     return (
       <div>
          <label>Select a State:</label>
          <select value={selected}>
            {selected === initialValue && 
                <option disabled value={initialValue}>{initialValue.value}</option>}
            {options.map((localState, index) => (
               <option key={localState.id} value={localState}>
                   {localState.value}
               </option>
             ))}
          </select>
        </div>
      ); 
};

const rootElement = document.getElementById("root");
ReactDOM.render(<StateSelector />, rootElement);

HTTP Error 500.30 - ANCM In-Process Start Failure

I have met this problem because I edit the Program.cs and I delete the Run function. Just add it again:

enter image description here

"Repository does not have a release file" error

In my case the cause was Ubuntu version no longer supported by Canonical. I was able to upgrade to still supported LTS with 2 steps:

1) Manually update repo links from "in.ubuntu" to "old-releases.ubuntu". 1.1) Installed all outstanding updates 2) do-release-upgrade was able to take from this point and do actual upgrade

IMHO, this is safer method then just updating repositories to next supported ubuntu, since do-release-upgrade have chance to prevent upgrade that could fail, and may be able to diagnose a problem for you.

Can I set state inside a useEffect hook

useEffect can hook on a certain prop or state. so, the thing you need to do to avoid infinite loop hook is binding some variable or state to effect

For Example:

useEffect(myeffectCallback, [])

above effect will fire only once the component has rendered. this is similar to componentDidMount lifecycle

const [something, setSomething] = withState(0)
const [myState, setMyState] = withState(0)
useEffect(() => {
  setSomething(0)
}, myState)

above effect will fire only my state has changed this is similar to componentDidUpdate except not every changing state will fire it.

You can read more detail though this link

Android Gradle 5.0 Update:Cause: org.jetbrains.plugins.gradle.tooling.util

For anybody facing a similar issue at this point in time, all you need to do is update your Android Studio to the latest version

TypeScript and React - children type?

As a type that contains children, I'm using:

type ChildrenContainer = Pick<JSX.IntrinsicElements["div"], "children">

This children container type is generic enough to support all the different cases and also aligned with the ReactJS API.

So, for your example it would be something like:

const layout = ({ children }: ChildrenContainer) => (
    <Aux>
        <div>Toolbar, SideDrawer, Backdrop</div>
        <main>
            {children}
        </main>
    <Aux/>
)

ping: google.com: Temporary failure in name resolution

I've faced the exactly same problem but I've fixed it with another approache.

Using Ubuntu 18.04, first disable systemd-resolved service.

sudo systemctl disable systemd-resolved.service

Stop the service

sudo systemctl stop systemd-resolved.service

Then, remove the link to /run/systemd/resolve/stub-resolv.conf in /etc/resolv.conf

sudo rm /etc/resolv.conf

Add a manually created resolv.conf in /etc/

sudo vim /etc/resolv.conf

Add your prefered DNS server there

nameserver 208.67.222.222

I've tested this with success.

Pandas Merging 101

This post aims to give readers a primer on SQL-flavored merging with pandas, how to use it, and when not to use it.

In particular, here's what this post will go through:

  • The basics - types of joins (LEFT, RIGHT, OUTER, INNER)

    • merging with different column names
    • merging with multiple columns
    • avoiding duplicate merge key column in output

What this post (and other posts by me on this thread) will not go through:

  • Performance-related discussions and timings (for now). Mostly notable mentions of better alternatives, wherever appropriate.
  • Handling suffixes, removing extra columns, renaming outputs, and other specific use cases. There are other (read: better) posts that deal with that, so figure it out!

Note
Most examples default to INNER JOIN operations while demonstrating various features, unless otherwise specified.

Furthermore, all the DataFrames here can be copied and replicated so you can play with them. Also, see this post on how to read DataFrames from your clipboard.

Lastly, all visual representation of JOIN operations have been hand-drawn using Google Drawings. Inspiration from here.



Enough Talk, just show me how to use merge!

Setup & Basics

np.random.seed(0)
left = pd.DataFrame({'key': ['A', 'B', 'C', 'D'], 'value': np.random.randn(4)})    
right = pd.DataFrame({'key': ['B', 'D', 'E', 'F'], 'value': np.random.randn(4)})
  
left

  key     value
0   A  1.764052
1   B  0.400157
2   C  0.978738
3   D  2.240893

right

  key     value
0   B  1.867558
1   D -0.977278
2   E  0.950088
3   F -0.151357

For the sake of simplicity, the key column has the same name (for now).

An INNER JOIN is represented by

Note
This, along with the forthcoming figures all follow this convention:

  • blue indicates rows that are present in the merge result
  • red indicates rows that are excluded from the result (i.e., removed)
  • green indicates missing values that are replaced with NaNs in the result

To perform an INNER JOIN, call merge on the left DataFrame, specifying the right DataFrame and the join key (at the very least) as arguments.

left.merge(right, on='key')
# Or, if you want to be explicit
# left.merge(right, on='key', how='inner')

  key   value_x   value_y
0   B  0.400157  1.867558
1   D  2.240893 -0.977278

This returns only rows from left and right which share a common key (in this example, "B" and "D).

A LEFT OUTER JOIN, or LEFT JOIN is represented by

This can be performed by specifying how='left'.

left.merge(right, on='key', how='left')

  key   value_x   value_y
0   A  1.764052       NaN
1   B  0.400157  1.867558
2   C  0.978738       NaN
3   D  2.240893 -0.977278

Carefully note the placement of NaNs here. If you specify how='left', then only keys from left are used, and missing data from right is replaced by NaN.

And similarly, for a RIGHT OUTER JOIN, or RIGHT JOIN which is...

...specify how='right':

left.merge(right, on='key', how='right')

  key   value_x   value_y
0   B  0.400157  1.867558
1   D  2.240893 -0.977278
2   E       NaN  0.950088
3   F       NaN -0.151357

Here, keys from right are used, and missing data from left is replaced by NaN.

Finally, for the FULL OUTER JOIN, given by

specify how='outer'.

left.merge(right, on='key', how='outer')

  key   value_x   value_y
0   A  1.764052       NaN
1   B  0.400157  1.867558
2   C  0.978738       NaN
3   D  2.240893 -0.977278
4   E       NaN  0.950088
5   F       NaN -0.151357

This uses the keys from both frames, and NaNs are inserted for missing rows in both.

The documentation summarizes these various merges nicely:

enter image description here


Other JOINs - LEFT-Excluding, RIGHT-Excluding, and FULL-Excluding/ANTI JOINs

If you need LEFT-Excluding JOINs and RIGHT-Excluding JOINs in two steps.

For LEFT-Excluding JOIN, represented as

Start by performing a LEFT OUTER JOIN and then filtering (excluding!) rows coming from left only,

(left.merge(right, on='key', how='left', indicator=True)
     .query('_merge == "left_only"')
     .drop('_merge', 1))

  key   value_x  value_y
0   A  1.764052      NaN
2   C  0.978738      NaN

Where,

left.merge(right, on='key', how='left', indicator=True)

  key   value_x   value_y     _merge
0   A  1.764052       NaN  left_only
1   B  0.400157  1.867558       both
2   C  0.978738       NaN  left_only
3   D  2.240893 -0.977278       both

And similarly, for a RIGHT-Excluding JOIN,

(left.merge(right, on='key', how='right', indicator=True)
     .query('_merge == "right_only"')
     .drop('_merge', 1))

  key  value_x   value_y
2   E      NaN  0.950088
3   F      NaN -0.151357

Lastly, if you are required to do a merge that only retains keys from the left or right, but not both (IOW, performing an ANTI-JOIN),

You can do this in similar fashion—

(left.merge(right, on='key', how='outer', indicator=True)
     .query('_merge != "both"')
     .drop('_merge', 1))

  key   value_x   value_y
0   A  1.764052       NaN
2   C  0.978738       NaN
4   E       NaN  0.950088
5   F       NaN -0.151357

Different names for key columns

If the key columns are named differently—for example, left has keyLeft, and right has keyRight instead of key—then you will have to specify left_on and right_on as arguments instead of on:

left2 = left.rename({'key':'keyLeft'}, axis=1)
right2 = right.rename({'key':'keyRight'}, axis=1)

left2
 
  keyLeft     value
0       A  1.764052
1       B  0.400157
2       C  0.978738
3       D  2.240893

right2

  keyRight     value
0        B  1.867558
1        D -0.977278
2        E  0.950088
3        F -0.151357
left2.merge(right2, left_on='keyLeft', right_on='keyRight', how='inner')

  keyLeft   value_x keyRight   value_y
0       B  0.400157        B  1.867558
1       D  2.240893        D -0.977278

Avoiding duplicate key column in output

When merging on keyLeft from left and keyRight from right, if you only want either of the keyLeft or keyRight (but not both) in the output, you can start by setting the index as a preliminary step.

left3 = left2.set_index('keyLeft')
left3.merge(right2, left_index=True, right_on='keyRight')
    
    value_x keyRight   value_y
0  0.400157        B  1.867558
1  2.240893        D -0.977278

Contrast this with the output of the command just before (that is, the output of left2.merge(right2, left_on='keyLeft', right_on='keyRight', how='inner')), you'll notice keyLeft is missing. You can figure out what column to keep based on which frame's index is set as the key. This may matter when, say, performing some OUTER JOIN operation.


Merging only a single column from one of the DataFrames

For example, consider

right3 = right.assign(newcol=np.arange(len(right)))
right3
  key     value  newcol
0   B  1.867558       0
1   D -0.977278       1
2   E  0.950088       2
3   F -0.151357       3

If you are required to merge only "new_val" (without any of the other columns), you can usually just subset columns before merging:

left.merge(right3[['key', 'newcol']], on='key')

  key     value  newcol
0   B  0.400157       0
1   D  2.240893       1

If you're doing a LEFT OUTER JOIN, a more performant solution would involve map:

# left['newcol'] = left['key'].map(right3.set_index('key')['newcol']))
left.assign(newcol=left['key'].map(right3.set_index('key')['newcol']))

  key     value  newcol
0   A  1.764052     NaN
1   B  0.400157     0.0
2   C  0.978738     NaN
3   D  2.240893     1.0

As mentioned, this is similar to, but faster than

left.merge(right3[['key', 'newcol']], on='key', how='left')

  key     value  newcol
0   A  1.764052     NaN
1   B  0.400157     0.0
2   C  0.978738     NaN
3   D  2.240893     1.0

Merging on multiple columns

To join on more than one column, specify a list for on (or left_on and right_on, as appropriate).

left.merge(right, on=['key1', 'key2'] ...)

Or, in the event the names are different,

left.merge(right, left_on=['lkey1', 'lkey2'], right_on=['rkey1', 'rkey2'])

Other useful merge* operations and functions

This section only covers the very basics, and is designed to only whet your appetite. For more examples and cases, see the documentation on merge, join, and concat as well as the links to the function specs.



Continue Reading

Jump to other topics in Pandas Merging 101 to continue learning:

* you are here

Why do I keep getting Delete 'cr' [prettier/prettier]?

All the answers above are correct, but when I use windows and disable the Prettier ESLint extension rvest.vs-code-prettier-eslint the issue will be fixed.

How to post query parameters with Axios?

In my case, the API responded with a CORS error. I instead formatted the query parameters into query string. It successfully posted data and also avoided the CORS issue.

        var data = {};

        const params = new URLSearchParams({
          contact: this.ContactPerson,
          phoneNumber: this.PhoneNumber,
          email: this.Email
        }).toString();

        const url =
          "https://test.com/api/UpdateProfile?" +
          params;

        axios
          .post(url, data, {
            headers: {
              aaid: this.ID,
              token: this.Token
            }
          })
          .then(res => {
            this.Info = JSON.parse(res.data);
          })
          .catch(err => {
            console.log(err);
          });

Numpy, multiply array with scalar

Using .multiply() (ufunc multiply)

a_1 = np.array([1.0, 2.0, 3.0])
a_2 = np.array([[1., 2.], [3., 4.]])
b = 2.0 

np.multiply(a_1,b)
# array([2., 4., 6.])
np.multiply(a_2,b)
# array([[2., 4.],[6., 8.]])

How to use componentWillMount() in React Hooks?

Just simply add an empty dependenncy array in useEffect it will works as componentDidMount.

useEffect(() => {
  // Your code here
  console.log("componentDidMount")
}, []);

React Hook Warnings for async function in useEffect: useEffect function must return a cleanup function or nothing

I read through this question, and feel the best way to implement useEffect is not mentioned in the answers. Let's say you have a network call, and would like to do something once you have the response. For the sake of simplicity, let's store the network response in a state variable. One might want to use action/reducer to update the store with the network response.

const [data, setData] = useState(null);

/* This would be called on initial page load */
useEffect(()=>{
    fetch(`https://www.reddit.com/r/${subreddit}.json`)
    .then(data => {
        setData(data);
    })
    .catch(err => {
        /* perform error handling if desired */
    });
}, [])

/* This would be called when store/state data is updated */
useEffect(()=>{
    if (data) {
        setPosts(data.children.map(it => {
            /* do what you want */
        }));
    }
}, [data]);

Reference => https://reactjs.org/docs/hooks-effect.html#tip-optimizing-performance-by-skipping-effects

Receiving "Attempted import error:" in react app

i had the same issue, but I just typed export on top and erased the default one on the bottom. Scroll down and check the comments.

import React, { Component } from "react";

export class Counter extends Component { // type this  
export default Counter; // this is eliminated  

Has been blocked by CORS policy: Response to preflight request doesn’t pass access control check

The only thing that worked for me was creating a new application in the IIS, mapping it to exactly the same physical path, and changing only the authentication to be Anonymous.

Xcode 10.2.1 Command PhaseScriptExecution failed with a nonzero exit code

For me the reason was while changing name of app I added a single quote ' in name. I tried different solution and ran into different errors, but at last, while renaming app, I did not include ' single quote and it solved the problem.

How can I force component to re-render with hooks in React?

My variation of forceUpdate is not via a counter but rather via an object:

// Emulates `forceUpdate()`
const [unusedState, setUnusedState] = useState()
const forceUpdate = useCallback(() => setUnusedState({}), [])

Because {} !== {} every time.

What is the meaning of "Failed building wheel for X" in pip install?

On Ubuntu 18.04, I ran into this issue because the apt package for wheel does not include the wheel command. I think pip tries to import the wheel python package, and if that succeeds assumes that the wheel command is also available. Ubuntu breaks that assumption.

The apt python3 code package is named python3-wheel. This is installed automatically because python3-pip recommends it.

The apt python3 wheel command package is named python-wheel-common. Installing this too fixes the "failed building wheel" errors for me.

What is useState() in React?

useState() is an example built-in React hook that lets you use states in your functional components. This was not possible before React 16.7.

The useState function is a built in hook that can be imported from the react package. It allows you to add state to your functional components. Using the useState hook inside a function component, you can create a piece of state without switching to class components.

How to call loading function with React useEffect only once

useMountEffect hook

Running a function only once after component mounts is such a common pattern that it justifies a hook of it's own that hides implementation details.

const useMountEffect = (fun) => useEffect(fun, [])

Use it in any functional component.

function MyComponent() {
    useMountEffect(function) // function will run only once after it has mounted. 
    return <div>...</div>;
}

About the useMountEffect hook

When using useEffect with a second array argument, React will run the callback after mounting (initial render) and after values in the array have changed. Since we pass an empty array, it will run only after mounting.

Selenium: WebDriverException:Chrome failed to start: crashed as google-chrome is no longer running so ChromeDriver is assuming that Chrome has crashed

Make sure that both the chromedriver and google-chrome executable have execute permissions

sudo chmod -x "/usr/bin/chromedriver"

sudo chmod -x "/usr/bin/google-chrome"

How to set width of mat-table column in angular?

If you're using scss for your styles you can use a mixin to help generate the code. Your styles will quickly get out of hand if you put all the properties every time.

This is a very simple example - really nothing more than a proof of concept, you can extend this with multiple properties and rules as needed.

@mixin mat-table-columns($columns)
{
    .mat-column-
    {
        @each $colName, $props in $columns {

            $width: map-get($props, 'width');

            &#{$colName} 
            {
                flex: $width;
                min-width: $width;

                @if map-has-key($props, 'color') 
                {
                    color: map-get($props, 'color');
                }
            }  
        }
    }
}

Then in your component where your table is defined you just do this:

@include mat-table-columns((

    orderid: (width: 6rem, color: gray),
    date: (width: 9rem),
    items: (width: 20rem)

));

This generates something like this:

.mat-column-orderid[_ngcontent-c15] {
  flex: 6rem;
  min-width: 6rem;
  color: gray; }

.mat-column-date[_ngcontent-c15] {
  flex: 9rem;
  min-width: 9rem; }

In this version width becomes flex: value; min-width: value.

For your specific example you could add wrap: true or something like that as a new parameter.

expected assignment or function call: no-unused-expressions ReactJS

If You're using JSX inside a function with curly braces you need to modify it to parenthesis.

Wrong Code

return this.props.todos.map((todo) => {
            <h3> {todo.author} </h3>;
        });

Correct Code

//Change Curly Brace To Paranthesis   change {} to => ()
return this.props.todos.map((todo) => (
            <h3> {todo.author} </h3>;
        ));

ImageMagick security policy 'PDF' blocking conversion

I was experiencing this issue with nextcloud which would fail to create thumbnails for pdf files.

However, none of the suggested steps would solve the issue for me.

Eventually I found the reason: The accepted answer did work but I had to also restart php-fpm after editing the policy.xml file:

 sudo systemctl restart php7.2-fpm.service

Flutter: RenderBox was not laid out

Placing your list view in a Flexible widget may also help,

Flexible( fit: FlexFit.tight, child: _buildYourListWidget(..),)

WebView showing ERR_CLEARTEXT_NOT_PERMITTED although site is HTTPS

When you call "https://darkorbit.com/" your server figures that it's missing "www" so it redirects the call to "http://www.darkorbit.com/" and then to "https://www.darkorbit.com/", your WebView call is blocked at the first redirection as it's a "http" call. You can call "https://www.darkorbit.com/" instead and it will solve the issue.

pod has unbound PersistentVolumeClaims

You have to define a PersistentVolume providing disc space to be consumed by the PersistentVolumeClaim.

When using storageClass Kubernetes is going to enable "Dynamic Volume Provisioning" which is not working with the local file system.


To solve your issue:

  • Provide a PersistentVolume fulfilling the constraints of the claim (a size >= 100Mi)
  • Remove the storageClass-line from the PersistentVolumeClaim
  • Remove the StorageClass from your cluster

How do these pieces play together?

At creation of the deployment state-description it is usually known which kind (amount, speed, ...) of storage that application will need.
To make a deployment versatile you'd like to avoid a hard dependency on storage. Kubernetes' volume-abstraction allows you to provide and consume storage in a standardized way.

The PersistentVolumeClaim is used to provide a storage-constraint alongside the deployment of an application.

The PersistentVolume offers cluster-wide volume-instances ready to be consumed ("bound"). One PersistentVolume will be bound to one claim. But since multiple instances of that claim may be run on multiple nodes, that volume may be accessed by multiple nodes.

A PersistentVolume without StorageClass is considered to be static.

"Dynamic Volume Provisioning" alongside with a StorageClass allows the cluster to provision PersistentVolumes on demand. In order to make that work, the given storage provider must support provisioning - this allows the cluster to request the provisioning of a "new" PersistentVolume when an unsatisfied PersistentVolumeClaim pops up.


Example PersistentVolume

In order to find how to specify things you're best advised to take a look at the API for your Kubernetes version, so the following example is build from the API-Reference of K8S 1.17:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: ckan-pv-home
  labels:
    type: local
spec:
  capacity:
    storage: 100Mi
  hostPath:
    path: "/mnt/data/ckan"

The PersistentVolumeSpec allows us to define multiple attributes. I chose a hostPath volume which maps a local directory as content for the volume. The capacity allows the resource scheduler to recognize this volume as applicable in terms of resource needs.


Additional Resources:

Git is not working after macOS Update (xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools)

For those using Catalina and Xcode-beta:

sudo xcode-select -s /Applications/Xcode-beta.app/Contents/Developer

How to install OpenJDK 11 on Windows?

From the comment by @ZhekaKozlov: ojdkbuild has OpenJDK builds (currently 8 and 11) for Windows (zip and msi).

How to install JDK 11 under Ubuntu?

sudo apt-get install openjdk-11-jdk

after this, try

java -version

to make sure java version is 1.11.x, if found old one or different, check below command to see the available jdks,

sudo update-java-alternatives --list

you should see something like below,

java-1.11.0-openjdk-amd64 1111 /usr/lib/jvm/java-1.11.0-openjdk-amd64

java-1.8.0-openjdk-amd64 1081 /usr/lib/jvm/java-1.8.0-openjdk-amd64

you can see java 1.11 available from above list, use below command to set java 11 to default,

sudo update-alternatives --config java

for above command, you will get something like below and also, will ask for an option to set,

There are 3 choices for the alternative java (providing /usr/bin/java).

Selection Path Priority Status


0 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 auto mode

1 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 manual mode

*2 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java 1081 manual mode

3 /usr/lib/jvm/jdk1.8.0_211/bin/java 0 manual mode

Press to keep the current choice[*], or type selection number:

you can select desired selection number, my case it's 0

for javac,

sudo update-alternatives --config javac

will result something like below,

There are 3 choices for the alternative javac (providing /usr/bin/javac).

Selection Path Priority Status


0 /usr/lib/jvm/java-11-openjdk-amd64/bin/javac 1111 auto mode

1 /usr/lib/jvm/java-11-openjdk-amd64/bin/javac 1111 manual mode

*2 /usr/lib/jvm/java-8-openjdk-amd64/bin/javac 1081 manual mode
3 /usr/lib/jvm/jdk1.8.0_211/bin/javac 0 manual mode

Press to keep the current choice[*], or type selection number:

in my case, it's 0 again

after above steps, try

java -version

it will display something like below,

openjdk version "11.0.4" 2019-07-16

OpenJDK Runtime Environment (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3)

OpenJDK 64-Bit Server VM (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3, mixed > mode, sharing)

WARNING: API 'variant.getJavaCompile()' is obsolete and has been replaced with 'variant.getJavaCompileProvider()'

Go back from classpath 'com.android.tools.build:gradle:3.3.0-alpha13' to classpath 'com.android.tools.build:gradle:3.2.0'

this worked for me

IntelliJ can't recognize JavaFX 11 with OpenJDK 11

The issue that JavaFX is no longer part of JDK 11. The following solution works using IntelliJ (haven't tried it with NetBeans):

  1. Add JavaFX Global Library as a dependency:

    Settings -> Project Structure -> Module. In module go to the Dependencies tab, and click the add "+" sign -> Library -> Java-> choose JavaFX from the list and click Add Selected, then Apply settings.

  2. Right click source file (src) in your JavaFX project, and create a new module-info.java file. Inside the file write the following code :

    module YourProjectName { 
        requires javafx.fxml;
        requires javafx.controls;
        requires javafx.graphics;
        opens sample;
    }
    

    These 2 steps will solve all your issues with JavaFX, I assure you.

Reference : There's a You Tube tutorial made by The Learn Programming channel, will explain all the details above in just 5 minutes. I also recommend watching it to solve your problem: https://www.youtube.com/watch?v=WtOgoomDewo

Difference between OpenJDK and Adoptium/AdoptOpenJDK

In short:

  • OpenJDK has multiple meanings and can refer to:
    • free and open source implementation of the Java Platform, Standard Edition (Java SE)
    • open source repository — the Java source code aka OpenJDK project
    • prebuilt OpenJDK binaries maintained by Oracle
    • prebuilt OpenJDK binaries maintained by the OpenJDK community
  • AdoptOpenJDK — prebuilt OpenJDK binaries maintained by community (open source licensed)

Explanation:

Prebuilt OpenJDK (or distribution) — binaries, built from http://hg.openjdk.java.net/, provided as an archive or installer, offered for various platforms, with a possible support contract.

OpenJDK, the source repository (also called OpenJDK project) - is a Mercurial-based open source repository, hosted at http://hg.openjdk.java.net. The Java source code. The vast majority of Java features (from the VM and the core libraries to the compiler) are based solely on this source repository. Oracle have an alternate fork of this.

OpenJDK, the distribution (see the list of providers below) - is free as in beer and kind of free as in speech, but, you do not get to call Oracle if you have problems with it. There is no support contract. Furthermore, Oracle will only release updates to any OpenJDK (the distribution) version if that release is the most recent Java release, including LTS (long-term support) releases. The day Oracle releases OpenJDK (the distribution) version 12.0, even if there's a security issue with OpenJDK (the distribution) version 11.0, Oracle will not release an update for 11.0. Maintained solely by Oracle.

Some OpenJDK projects - such as OpenJDK 8 and OpenJDK 11 - are maintained by the OpenJDK community and provide releases for some OpenJDK versions for some platforms. The community members have taken responsibility for releasing fixes for security vulnerabilities in these OpenJDK versions.

AdoptOpenJDK, the distribution is very similar to Oracle's OpenJDK distribution (in that it is free, and it is a build produced by compiling the sources from the OpenJDK source repository). AdoptOpenJDK as an entity will not be backporting patches, i.e. there won't be an AdoptOpenJDK 'fork/version' that is materially different from upstream (except for some build script patches for things like Win32 support). Meaning, if members of the community (Oracle or others, but not AdoptOpenJDK as an entity) backport security fixes to updates of OpenJDK LTS versions, then AdoptOpenJDK will provide builds for those. Maintained by OpenJDK community.

OracleJDK - is yet another distribution. Starting with JDK12 there will be no free version of OracleJDK. Oracle's JDK distribution offering is intended for commercial support. You pay for this, but then you get to rely on Oracle for support. Unlike Oracle's OpenJDK offering, OracleJDK comes with longer support for LTS versions. As a developer you can get a free license for personal/development use only of this particular JDK, but that's mostly a red herring, as 'just the binary' is basically the same as the OpenJDK binary. I guess it means you can download security-patched versions of LTS JDKs from Oracle's websites as long as you promise not to use them commercially.

Note. It may be best to call the OpenJDK builds by Oracle the "Oracle OpenJDK builds".

Donald Smith, Java product manager at Oracle writes:

Ideally, we would simply refer to all Oracle JDK builds as the "Oracle JDK", either under the GPL or the commercial license, depending on your situation. However, for historical reasons, while the small remaining differences exist, we will refer to them separately as Oracle’s OpenJDK builds and the Oracle JDK.


OpenJDK Providers and Comparison

----------------------------------------------------------------------------------------
|     Provider      | Free Builds | Free Binary   | Extended | Commercial | Permissive |
|                   | from Source | Distributions | Updates  | Support    | License    |
|--------------------------------------------------------------------------------------|
| AdoptOpenJDK      |    Yes      |    Yes        |   Yes    |   No       |   Yes      |
| Amazon – Corretto |    Yes      |    Yes        |   Yes    |   No       |   Yes      |
| Azul Zulu         |    No       |    Yes        |   Yes    |   Yes      |   Yes      |
| BellSoft Liberica |    No       |    Yes        |   Yes    |   Yes      |   Yes      |
| IBM               |    No       |    No         |   Yes    |   Yes      |   Yes      |
| jClarity          |    No       |    No         |   Yes    |   Yes      |   Yes      |
| OpenJDK           |    Yes      |    Yes        |   Yes    |   No       |   Yes      |
| Oracle JDK        |    No       |    Yes        |   No**   |   Yes      |   No       |
| Oracle OpenJDK    |    Yes      |    Yes        |   No     |   No       |   Yes      |
| ojdkbuild         |    Yes      |    Yes        |   No     |   No       |   Yes      |
| RedHat            |    Yes      |    Yes        |   Yes    |   Yes      |   Yes      |
| SapMachine        |    Yes      |    Yes        |   Yes    |   Yes      |   Yes      |
----------------------------------------------------------------------------------------

Free Builds from Source - the distribution source code is publicly available and one can assemble its own build

Free Binary Distributions - the distribution binaries are publicly available for download and usage

Extended Updates - aka LTS (long-term support) - Public Updates beyond the 6-month release lifecycle

Commercial Support - some providers offer extended updates and customer support to paying customers, e.g. Oracle JDK (support details)

Permissive License - the distribution license is non-protective, e.g. Apache 2.0


Which Java Distribution Should I Use?

In the Sun/Oracle days, it was usually Sun/Oracle producing the proprietary downstream JDK distributions based on OpenJDK sources. Recently, Oracle had decided to do their own proprietary builds only with the commercial support attached. They graciously publish the OpenJDK builds as well on their https://jdk.java.net/ site.

What is happening starting JDK 11 is the shift from single-vendor (Oracle) mindset to the mindset where you select a provider that gives you a distribution for the product, under the conditions you like: platforms they build for, frequency and promptness of releases, how support is structured, etc. If you don't trust any of existing vendors, you can even build OpenJDK yourself.

Each build of OpenJDK is usually made from the same original upstream source repository (OpenJDK “the project”). However each build is quite unique - $free or commercial, branded or unbranded, pure or bundled (e.g., BellSoft Liberica JDK offers bundled JavaFX, which was removed from Oracle builds starting JDK 11).

If no environment (e.g., Linux) and/or license requirement defines specific distribution and if you want the most standard JDK build, then probably the best option is to use OpenJDK by Oracle or AdoptOpenJDK.


Additional information

Time to look beyond Oracle's JDK by Stephen Colebourne

Java Is Still Free by Java Champions community (published on September 17, 2018)

Java is Still Free 2.0.0 by Java Champions community (published on March 3, 2019)

Aleksey Shipilev about JDK updates interview by Opsian (published on June 27, 2019)

Objects are not valid as a React child. If you meant to render a collection of children, use an array instead

In My case, I had a added async at app.js like shown below.

const App = async() => {
return(
<Text>Hello world</Text>
)
}

But it was not necessary, when testing something I had added it and it was no longer required. After removing it, as shown below, things started working.

 const App =() => {
    return(
    <Text>Hello world</Text>
    )
}

Xcode 10: A valid provisioning profile for this executable was not found

[edit] Note 2020: I used to manual sign this project. In projects where I automatically signed, I never had this issue. [/edit]

I had the same problem, and spent hours searching for an answer, removing profiles, cleaning project, and so on.

Have you distributed your app? You need to switch back to your developer profile, but not in General under the project settings, but in Build settings.

Under Signing, look at your Code Signing Identity.

Make sure that both your Debug and Release are set your iOS Developer, and not iOS Distribution; or your iOS Developer Provisioning profile, if not set to the automatic values.

The same goes with Provisioning Profile. It should be your developing profile, and not your distribution profile. enter image description here

Hope this will help future developers in need.

Xcode 10, Command CodeSign failed with a nonzero exit code

After i copied two .aiff files in a .scnassets group, this error occured. Deletion of the files and a "Clean Build Folder" solves the problem in my case.

How to reload current page?

I have solved following this way

import { Router, ActivatedRoute } from '@angular/router';

constructor(private router: Router
          , private activeRoute: ActivatedRoute) {

}
reloadCurrentPage(){
   let currentUrl = this.router.url;
   this.router.navigateByUrl('/', {skipLocationChange: true}).then(() => {
   this.router.navigate([currentUrl]);
   });
 }

Command CompileSwift failed with a nonzero exit code in Xcode 10

For me, just cleaning project works using ShiftCommandK & OptionShiftCommandK.

I can't install pyaudio on Windows? How to solve "error: Microsoft Visual C++ 14.0 is required."?

You should install python 3.6 version because python 3.7 version doesn't support pyaudio 1 step : Then download the .whl file
according to your python version and the configuration of your machine in your python folder which is newly installed. For me it is python 3.6 and 64 bit machine. Download the file from here (https://www.lfd.uci.edu/~gohlke/pythonlibs/) 2 step : run your cmd and type " pip install your downloaded file name here "

GoogleMaps API KEY for testing

Updated Answer

As of June11, 2018 it is now mandatory to have a billing account to get API key. You can still make keyless calls to the Maps JavaScript API and Street View Static API which will return low-resolution maps that can be used for development. Enabling billing still gives you $200 free credit monthly for your projects.

This answer is no longer valid

As long as you're using a testing API key it is free to register and use. But when you move your app to commercial level you have to pay for it. When you enable billing, google gives you $200 credit free each month that means if your app's map usage is low you can still use it for free even after the billing enabled, if it exceeds the credit limit now you have to pay for it.

How to open a link in new tab using angular?

Try this:

 window.open(this.url+'/create-account')

No need to use '_blank'. window.open by default opens a link in a new tab.

Support for the experimental syntax 'classProperties' isn't currently enabled

yarn add --dev @babel/plugin-proposal-class-properties

or

npm install @babel/plugin-proposal-class-properties --save-dev .babelrc

DeprecationWarning: Buffer() is deprecated due to security and usability issues when I move my script to another server

The use of the deprecated new Buffer() constructor (i.E. as used by Yarn) can cause deprecation warnings. Therefore one should NOT use the deprecated/unsafe Buffer constructor.

According to the deprecation warning new Buffer() should be replaced with one of:

  • Buffer.alloc()
  • Buffer.allocUnsafe() or
  • Buffer.from()

Another option in order to avoid this issue would be using the safe-buffer package instead.

You can also try (when using yarn..):

yarn global add yarn

as mentioned here: Link

Another suggestion from the comments (thx to gkiely): self-update

Note: self-update is not available. See policies for enforcing versions within a project

In order to update your version of Yarn, run

curl --compressed -o- -L https://yarnpkg.com/install.sh | bash

Starting ssh-agent on Windows 10 fails: "unable to start ssh-agent service, error :1058"

I solved the problem by changing the StartupType of the ssh-agent to Manual via Set-Service ssh-agent -StartupType Manual.

Then I was able to start the service via Start-Service ssh-agent or just ssh-agent.exe.

Flutter - The method was called on null

Because of your initialization wrong.

Don't do like this,

MethodName _methodName;

Do like this,

MethodName _methodName = MethodName();

Can I use library that used android support with Androidx projects.

I used these two lines of code in application tag in manifest.xml and it worked.

 tools:replace="android:appComponentFactory"    
 android:appComponentFactory="whateverString"

Source: https://github.com/android/android-ktx/issues/576#issuecomment-437145192

ERROR Error: Uncaught (in promise), Cannot match any routes. URL Segment

In case you need the [] syntax, useful for "edit forms" when you need to pass parameters like id with the route, you would do something like:

[routerLink]="['edit', business._id]"

As for an "about page" with no parameters like yours,

[routerLink]="/about"

or

[routerLink]=['about']

will do the trick.

How to convert string to boolean in typescript Angular 4

In your scenario, converting a string to a boolean can be done via something like someString === 'true' (as was already answered).

However, let me try to address your main issue: dealing with the local storage.

The local storage only supports strings as values; a good way of using it would thus be to always serialise your data as a string before storing it in the storage, and reversing the process when fetching it.

A possibly decent format for serialising your data in is JSON, since it is very easy to deal with in JavaScript.

The following functions could thus be used to interact with local storage, provided that your data can be serialised into JSON.

function setItemInStorage(key, item) {
  localStorage.setItem(key, JSON.stringify(item));
}

function getItemFromStorage(key) {
  return JSON.parse(localStorage.getItem(key));
}

Your example could then be rewritten as:

setItemInStorage('CheckOutPageReload', [this.btnLoginNumOne, this.btnLoginEdit]);

And:

if (getItemFromStorage('CheckOutPageReload')) {
  const pageLoadParams = getItemFromStorage('CheckOutPageReload');
  this.btnLoginNumOne = pageLoadParams[0];
  this.btnLoginEdit = pageLoadParams[1];
}

What is the Record type in typescript?

  1. Can someone give a simple definition of what Record is?

A Record<K, T> is an object type whose property keys are K and whose property values are T. That is, keyof Record<K, T> is equivalent to K, and Record<K, T>[K] is (basically) equivalent to T.

  1. Is Record<K,T> merely a way of saying "all properties on this object will have type T"? Probably not all objects, since K has some purpose...

As you note, K has a purpose... to limit the property keys to particular values. If you want to accept all possible string-valued keys, you could do something like Record<string, T>, but the idiomatic way of doing that is to use an index signature like { [k: string]: T }.

  1. Does the K generic forbid additional keys on the object that are not K, or does it allow them and just indicate that their properties are not transformed to T?

It doesn't exactly "forbid" additional keys: after all, a value is generally allowed to have properties not explicitly mentioned in its type... but it wouldn't recognize that such properties exist:

declare const x: Record<"a", string>;
x.b; // error, Property 'b' does not exist on type 'Record<"a", string>'

and it would treat them as excess properties which are sometimes rejected:

declare function acceptR(x: Record<"a", string>): void;
acceptR({a: "hey", b: "you"}); // error, Object literal may only specify known properties

and sometimes accepted:

const y = {a: "hey", b: "you"};
acceptR(y); // okay
  1. With the given example:

    type ThreeStringProps = Record<'prop1' | 'prop2' | 'prop3', string>
    

    Is it exactly the same as this?:

    type ThreeStringProps = {prop1: string, prop2: string, prop3: string}
    

Yes!

Hope that helps. Good luck!

Flutter- wrapping text

In a project of mine I wrap Text instances around Containers. This particular code sample features two stacked Text objects.

Here's a code sample.

    //80% of screen width
    double c_width = MediaQuery.of(context).size.width*0.8;

    return new Container (
      padding: const EdgeInsets.all(16.0),
      width: c_width,
      child: new Column (
        children: <Widget>[
          new Text ("Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 Long text 1 ", textAlign: TextAlign.left),
          new Text ("Long Text 2, Long Text 2, Long Text 2, Long Text 2, Long Text 2, Long Text 2, Long Text 2, Long Text 2, Long Text 2, Long Text 2, Long Text 2", textAlign: TextAlign.left),
        ],
      ),
    );

[edit] Added a width constraint to the container

Iterating over arrays in Python 3

You can use

    nditer

Here I calculated no. of positive and negative coefficients in a logistic regression:

b=sentiment_model.coef_
pos_coef=0
neg_coef=0
for i in np.nditer(b):
    if i>0:
    pos_coef=pos_coef+1
    else:
    neg_coef=neg_coef+1
print("no. of positive coefficients is : {}".format(pos_coef))
print("no. of negative coefficients is : {}".format(neg_coef))

Output:

no. of positive coefficients is : 85035
no. of negative coefficients is : 36199

Could not install packages due to an EnvironmentError: [WinError 5] Access is denied:

Step 1 - Open anaconda prompt with administrator privileges.

Step 2 - check pip version pip --version

Step 3 - enter this command

     **python -m pip install --upgrade pip**

enter image description here

Android Material and appcompat Manifest merger failed

Reason of Fail

You are using material library which is part of AndroidX. If you are not aware of AndroidX, please go through this answer.

One app should use either AndroidX or old Android Support libraries. That's why you faced this issue.

For example -

In your gradle, you are using

  • com.android.support:appcompat-v7 (Part of old --Android Support Library--)
  • com.google.android.material:material (Part of AndroidX) (AndroidX build artifact of com.android.support:design)

Solution

So the solution is to use either AndroidX or old Support Library. I recommend to use AndroidX, because Android will not update support libraries after version 28.0.0. See release notes of Support Library.

Just migrate to AndroidX.Here is my detailed answer to migrate to AndroidX. I am putting here the needful steps from that answer.

Before you migrate, it is strongly recommended to backup your project.

Existing project

  • Android Studio > Refactor Menu > Migrate to AndroidX...
  • It will analysis and will open Refractor window in bottom. Accept changes to be done.

image

New project

Put these flags in your gradle.properties

android.enableJetifier=true
android.useAndroidX=true

Check @Library mappings for equal AndroidX package.

Check @Official page of Migrate to AndroidX

What is Jetifier?

Find the smallest positive integer that does not occur in a given sequence

function solution(A = []) {
    return (A && A
        .filter(num => num > 0)
        .sort((a, b) => a - b)
        .reduce((acc, curr, idx, arr) => 
            !arr.includes(acc + 1) ? acc : curr, 0)
        ) + 1;
}

solution(); // 1 solution(null); // 1 solution([]); // 1 solution([0, 0, 0]); // 1

Angular: How to download a file from HttpClient?

I ended up here when searching for ”rxjs download file using post”.

This was my final product. It uses the file name and type given in the server response.

import { ajax, AjaxResponse } from 'rxjs/ajax';
import { map } from 'rxjs/operators';

downloadPost(url: string, data: any) {
    return ajax({
        url: url,
        method: 'POST',
        responseType: 'blob',
        body: data,
        headers: {
            'Content-Type': 'application/json',
            'Accept': 'text/plain, */*',
            'Cache-Control': 'no-cache',
        }
    }).pipe(
        map(handleDownloadSuccess),
    );
}


handleDownloadSuccess(response: AjaxResponse) {
    const downloadLink = document.createElement('a');
    downloadLink.href = window.URL.createObjectURL(response.response);

    const disposition = response.xhr.getResponseHeader('Content-Disposition');
    if (disposition) {
        const filenameRegex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/;
        const matches = filenameRegex.exec(disposition);
        if (matches != null && matches[1]) {
            const filename = matches[1].replace(/['"]/g, '');
            downloadLink.setAttribute('download', filename);
        }
    }

    document.body.appendChild(downloadLink);
    downloadLink.click();
    document.body.removeChild(downloadLink);
}

Under which circumstances textAlign property works in Flutter?

textAlign property only works when there is a more space left for the Text's content. Below are 2 examples which shows when textAlign has impact and when not.


No impact

For instance, in this example, it won't have any impact because there is no extra space for the content of the Text.

Text(
  "Hello",
  textAlign: TextAlign.end, // no impact
),

enter image description here


Has impact

If you wrap it in a Container and provide extra width such that it has more extra space.

Container(
  width: 200,
  color: Colors.orange,
  child: Text(
    "Hello",
    textAlign: TextAlign.end, // has impact
  ),
)

enter image description here

Confirm password validation in Angular 6

Single method for Reactive Forms

TYPESCRIPT

// All is this method
onPasswordChange() {
  if (this.confirm_password.value == this.password.value) {
    this.confirm_password.setErrors(null);
  } else {
    this.confirm_password.setErrors({ mismatch: true });
  }
}

// getting the form control elements
get password(): AbstractControl {
  return this.form.controls['password'];
}

get confirm_password(): AbstractControl {
  return this.form.controls['confirm_password'];
}

HTML

// PASSWORD FIELD
<input type="password" formControlName="password" />

// CONFIRM PASSWORD FIELD
<input type="password" formControlName="confirm_password" (change)="onPasswordChange()" />

// SHOW ERROR IF MISMATCH
<span *ngIf="confirm_password.hasError('mismatch')">Password do not match.</span>

Angular 6: saving data to local storage

you can use localStorage for storing the json data:

the example is given below:-

let JSONDatas = [
    {"id": "Open"},
    {"id": "OpenNew", "label": "Open New"},
    {"id": "ZoomIn", "label": "Zoom In"},
    {"id": "ZoomOut", "label": "Zoom Out"},
    {"id": "Find", "label": "Find..."},
    {"id": "FindAgain", "label": "Find Again"},
    {"id": "Copy"},
    {"id": "CopyAgain", "label": "Copy Again"},
    {"id": "CopySVG", "label": "Copy SVG"},
    {"id": "ViewSVG", "label": "View SVG"}
]

localStorage.setItem("datas", JSON.stringify(JSONDatas));

let data = JSON.parse(localStorage.getItem("datas"));

console.log(data);

standard_init_linux.go:190: exec user process caused "no such file or directory" - Docker

Replacing CRLF with LF using Notepad++

  1. Notepad++'s Find/Replace feature handles this requirement quite nicely. Simply bring up the Replace dialogue (CTRL+H), select Extended search mode (ALT+X), search for “\r\n” and replace with “\n”:
  2. Hit Replace All (ALT+A)

Rebuild and run the docker image should solve your problem.

MySQL Update Column +1?

You can do:

UPDATE categories SET posts = posts + 1 WHERE category_id = 42;

How may I align text to the left and text to the right in the same line?

While several of the solutions here will work, none handle overlap well and end up moving one item to below the other. If you are trying to layout data that will be dynamically bound you won't know until runtime that it looks bad.

What I like to do is simply create a single row table and apply the right float on the second cell. No need to apply a left-align on the first, that happens by default. This handles overlap perfectly by word-wrapping.

HTML

<table style="width: 100%;">
  <tr><td>Left aligned stuff</td>
      <td class="alignRight">Right aligned stuff</td></tr>
</table>

CSS

.alignRight {
  float: right;
}

https://jsfiddle.net/esoyke/7wddxks5/

How to use RANK() in SQL Server

SELECT contendernum,totals, RANK() OVER (ORDER BY totals ASC) AS xRank FROM
(
SELECT ContenderNum ,SUM(Criteria1+Criteria2+Criteria3+Criteria4) AS totals
FROM dbo.Cat1GroupImpersonation
 GROUP BY ContenderNum
) AS a

Creating a Plot Window of a Particular Size

Use dev.new(). (See this related question.)

plot(1:10)
dev.new(width=5, height=4)
plot(1:20)

To be more specific which units are used:

dev.new(width=5, height=4, unit="in")
plot(1:20)
dev.new(width = 550, height = 330, unit = "px")
plot(1:15)

edit additional argument for Rstudio (May 2020), (thanks user Soren Havelund Welling)

For Rstudio, add dev.new(width=5,height=4,noRStudioGD = TRUE)

How can I add spaces between two <input> lines using CSS?

Try to minimize the use of <br> as much as you possibly can. HTML is supposed to carry content and structure, <br> is neither. A simple workaround is to wrap your input elements in <p> elements, like so:

<form name="publish" id="publish" action="publishprocess.php" method="post">

    <p><input type="text" id="title" name="title" size="60" maxlength="110" value="<?php echo $title ?>" /> - Title</p>
    <p><input type="text" id="contact" name="contact" size="24" maxlength="30" value="<?php echo $contact ?>" /> - Contact</p>

    <p>Task description (you may include task description, requirements on bidders, time requirements, etc):</p>
    <p><textarea name="detail" id="detail" rows="7" cols="60" style="font-family:Arial, Helvetica, sans-serif"><?php echo $detail ?></textarea></p>

    <p><input type="text" id="price" name="price" size="10" maxlength="20" value="<?php echo $price ?>" /> - Price</p>

    <p><input class="tagvalidate" type="text" id="tag" name="tag" size="40" maxlength="60" value="<?php echo $tag ?>" /> - Skill or Knowledge Tags</p>
    <p>Combine multiple words into single-words, space to separate up to 3 tags (example:photoshop quantum-physics computer-programming)</p>

    <p>District Restriction:<?php echo $locationtext.$cityname; ?></p>

    <p><input type="submit" id="submit" value="Submit" /></p>
</form>

How to get a date in YYYY-MM-DD format from a TSQL datetime field?

This solution works for me, simple and effective (with 126 too)

CONVERT(NVARCHAR(MAX), CAST(GETDATE() as date), 120)

What is git tag, How to create tags & How to checkout git remote tag(s)

In order to checkout a git tag , you would execute the following command

git checkout tags/tag-name -b branch-name

eg as mentioned below.

 git checkout tags/v1.0 -b v1.0-branch

To fetch the all tags use the command

git fetch --all --tags

Include headers when using SELECT INTO OUTFILE?

I would like to add to the answer provided by Sangam Belose. Here's his code:

select ('id') as id, ('time') as time, ('unit') as unit
UNION ALL
SELECT * INTO OUTFILE 'C:/Users/User/Downloads/data.csv'
  FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
  LINES TERMINATED BY '\n'
  FROM sensor

However, if you have not set up your "secure_file_priv" within the variables, it may not work. For that, check the folder set on that variable by:

SHOW VARIABLES LIKE "secure_file_priv"

The output should look like this:

mysql> show variables like "%secure_file_priv%";
+------------------+------------------------------------------------+
| Variable_name    | Value                                          |
+------------------+------------------------------------------------+
| secure_file_priv | C:\ProgramData\MySQL\MySQL Server 8.0\Uploads\ |
+------------------+------------------------------------------------+
1 row in set, 1 warning (0.00 sec)

You can either change this variable or change the query to output the file to the default path showing.

Serializing list to JSON

If using Python 2.5, you may need to import simplejson:

try:
    import json
except ImportError:
    import simplejson as json

Convert the first element of an array to a string in PHP

Is there any other way to convert that array into string ?

Yes there is. serialize(). It can convert various data types (including object and arrays) into a string representation which you can unserialize() at a later time. Serializing an associative array such as Array(18 => 'Somthing') will preserve both keys and values:

<?php
$a = array(18 => 'Something');
echo serialize($a);                                   // a:1:{i:18;s:9:"Something";}
var_dump(unserialize('a:1:{i:18;s:9:"Something";}')); // array(1) {
                                                      //   [18]=>
                                                      //   string(9) "Something"
                                                      // }

Is it possible to get all arguments of a function as single object inside that function?

In ES6 you can do something like this:

_x000D_
_x000D_
function foo(...args) _x000D_
{_x000D_
   let [a,b,...c] = args;_x000D_
_x000D_
   console.log(a,b,c);_x000D_
}_x000D_
_x000D_
_x000D_
foo(1, null,"x",true, undefined);
_x000D_
_x000D_
_x000D_

Eventviewer eventid for lock and unlock

For newer versions of Windows (including but not limited to both Windows 10 and Windows Server 2016), the event IDs are:

  • 4800 - The workstation was locked.
  • 4801 - The workstation was unlocked.

Locking and unlocking a workstation also involve the following logon and logoff events:

  • 4624 - An account was successfully logged on.
  • 4634 - An account was logged off.
  • 4648 - A logon was attempted using explicit credentials.

When using a Terminal Services session, locking and unlocking may also involve the following events if the session is disconnected, and event 4778 may replace event 4801:

  • 4779 - A session was disconnected from a Window Station.
  • 4778 - A session was reconnected to a Window Station.

Events 4800 and 4801 are not audited by default, and must be enabled using either Local Group Policy Editor (gpedit.msc) or Local Security Policy (secpol.msc).

The path for the policy using Local Group Policy Editor is:

  • Local Computer Policy
  • Computer Configuration
  • Windows Settings
  • Security Settings
  • Advanced Audit Policy Configuration
  • System Audit Policies - Local Group Policy Object
  • Logon/Logoff
  • Audit Other Logon/Logoff Events

The path for the policy using Local Security Policy is the following subset of the path for Local Group Policy Editor:

  • Security Settings
  • Advanced Audit Policy Configuration
  • System Audit Policies - Local Group Policy Object
  • Logon/Logoff
  • Audit Other Logon/Logoff Events

Cycles in an Undirected Graph

Actually, depth first (or indeed breadth first) search isn't quite enough. You need a sightly more complex algorithm.

For instance, suppose there is graph with nodes {a,b,c,d} and edges {(a,b),(b,c),(b,d),(d,c)} where an edge (x,y) is an edge from x to y. (looks something like this, with all edges directed downwards.)

    (a)
     |
     |
    (b)
    / \ 
  (d)  |
   |   |
    \ /
    (c)

Then doing depth first search may visit node (a), then (b), then (c), then backtrack to (b), then visit (d), and finally visit (c) again and conclude there is a cycle -- when there isn't. A similar thing happens with breadth first.

What you need to do is keep track of which nodes your in the middle of visiting. In the example above, when the algorithm reaches (d) it has finished visiting (c) but not (a) or (b). So revisiting a finished node is fine, but visiting an unfinished node means you have a cycle. The usual way to do this is colour each node white(not yet visited), grey(visiting descendants) or black(finished visiting).

here is some pseudo code!

define visit(node n):
  if n.colour == grey: //if we're still visiting this node or its descendants
    throw exception("Cycle found")

  n.colour = grey //to indicate this node is being visited
  for node child in n.children():
    if child.colour == white: //if the child is unexplored
      visit(child)

  n.colour = black //to show we're done visiting this node
  return

then running visit(root_node) will throw an exception if and only if there is a cycle (initially all nodes should be white).

How do you run a single query through mysql from the command line?

mysql -uroot -p -hslavedb.mydomain.com mydb_production -e "select * from users;"

From the usage printout:

-e, --execute=name
Execute command and quit. (Disables --force and history file)

Git: how to reverse-merge a commit?

If I understand you correctly, you're talking about doing a

svn merge -rn:n-1

to back out of an earlier commit, in which case, you're probably looking for

git revert

issue ORA-00001: unique constraint violated coming in INSERT/UPDATE

select the index then select the ones needed then select sql and click action then click rebuild

enter image description here

extract column value based on another column pandas dataframe

Use df[df['B']==3]['A'].values if you just want item itself without the brackets

FirebaseInstanceIdService is deprecated

And this:

FirebaseInstanceId.getInstance().getInstanceId().getResult().getToken()

suppose to be solution of deprecated:

FirebaseInstanceId.getInstance().getToken()

EDIT

FirebaseInstanceId.getInstance().getInstanceId().getResult().getToken() can produce exception if the task is not yet completed, so the method witch Nilesh Rathod described (with .addOnSuccessListener) is correct way to do it.

Kotlin:

FirebaseInstanceId.getInstance().instanceId.addOnSuccessListener(this) { instanceIdResult ->
        val newToken = instanceIdResult.token
        Log.e("newToken", newToken)
    }

jQuery checkbox event handling

Acknowledging the fact that the asker specifically requested jQuery and that the answer selected is correct, it should be noted that this problem doesn't actually need jQuery per say. If one desires to solve this problem without it, one can simply set the onClick attribute of the checkboxes that he or she wants to add additional functionality to, like so:

HTML:

<form id="myform">
  <input type="checkbox" name="check1" value="check1" onClick="cbChanged(this);">
  <input type="checkbox" name="check2" value="check2" onClick="cbChanged(this);">
</form>

javascript:

function cbChanged(checkboxElem) {
  if (checkboxElem.checked) {
    // Do something special
  } else {
    // Do something else
  }
}

Fiddle: http://jsfiddle.net/Y9f66/1/

How to convert the system date format to dd/mm/yy in SQL Server 2008 R2?

select convert(varchar(8), getdate(), 3)

simply use this for dd/mm/yy and this

select convert(varchar(8), getdate(), 1) 

for mm/dd/yy

How can I calculate an md5 checksum of a directory?

Using md5deep:

md5deep -r FOLDER | awk '{print $1}' | sort | md5sum

How to avoid annoying error "declared and not used"

According to the FAQ:

Some have asked for a compiler option to turn those checks off or at least reduce them to warnings. Such an option has not been added, though, because compiler options should not affect the semantics of the language and because the Go compiler does not report warnings, only errors that prevent compilation.

There are two reasons for having no warnings. First, if it's worth complaining about, it's worth fixing in the code. (And if it's not worth fixing, it's not worth mentioning.) Second, having the compiler generate warnings encourages the implementation to warn about weak cases that can make compilation noisy, masking real errors that should be fixed.

I don't necessarily agree with this for various reasons not worth going into. It is what it is, and it's not likely to change in the near future.

For packages, there's the goimports tool which automatically adds missing packages and removes unused ones. For example:

# Install it
$ go get golang.org/x/tools/cmd/goimports

# -w to write the source file instead of stdout
$ goimports -w my_file.go

You should be able to run this from any half-way decent editor - for example for Vim:

:!goimports -w %

The goimports page lists some commands for other editors, and you typically set it to be run automatically when you save the buffer to disk.

Note that goimports will also run gofmt.


As was already mentioned, for variables the easiest way is to (temporarily) assign them to _ :

// No errors
tasty := "ice cream"
horrible := "marmite"

// Commented out for debugging
//eat(tasty, horrible)

_, _ = tasty, horrible

Polygon Drawing and Getting Coordinates with Google Map API v3

Adding to Gisheri's answer

Following code worked for me

 var drawingManager = new google.maps.drawing.DrawingManager({
    drawingMode: google.maps.drawing.OverlayType.MARKER,
    drawingControl: true,
    drawingControlOptions: {
      position: google.maps.ControlPosition.TOP_CENTER,
      drawingModes: [
        google.maps.drawing.OverlayType.POLYGON
      ]
    },
    markerOptions: {
      icon: 'images/beachflag.png'
    },
    circleOptions: {
      fillColor: '#ffff00',
      fillOpacity: 1,
      strokeWeight: 5,
      clickable: false,
      editable: true,
      zIndex: 1
    }

  });

  google.maps.event.addListener(drawingManager, 'overlaycomplete', function(polygon) {
      //console.log(polygon.overlay.latLngs.j[0].j);return false;
        $.each(polygon.overlay.latLngs.j[0].j, function(key, LatLongsObject){
            var LatLongs    =   LatLongsObject;

            var lat = LatLongs.k;
            var lon = LatLongs.B;
           console.log("Lat is: "+lat+" Long is: "+lon); //do something with the coordinates

        });

Centering image and text in R Markdown for a PDF report

The simple solution given by Jonathan works with a modification to cheat Pandoc. Instead of direct Latex commands such as

\begin{center}
Text
\end{center}

you can define your own commands in the YAML header:

header-includes:
- \newcommand{\bcenter}{\begin{center}}
- \newcommand{\ecenter}{\end{center}}

And then you use:

\bcenter
Text and more
\ecenter

This works for me for centering a whole document with many code chunks and markdown commands in between.

How to parse XML and count instances of a particular node attribute?

There's no need to use a lib specific API if you use python-benedict. Just initialize a new instance from your XML and manage it easily since it is a dict subclass.

Installation is easy: pip install python-benedict

from benedict import benedict as bdict

# data-source can be an url, a filepath or data-string (as in this example)
data_source = """
<foo>
   <bar>
      <type foobar="1"/>
      <type foobar="2"/>
   </bar>
</foo>"""

data = bdict.from_xml(data_source)
t_list = data['foo.bar'] # yes, keypath supported
for t in t_list:
   print(t['@foobar'])

It supports and normalizes I/O operations with many formats: Base64, CSV, JSON, TOML, XML, YAML and query-string.

It is well tested and open-source on GitHub. Disclosure: I am the author.

How do I combine two data-frames based on two columns?

Hope this helps;

df1 = data.frame(CustomerId=c(1:10),
             Hobby = c(rep("sing", 4), rep("pingpong", 3), rep("hiking", 3)),
             Product=c(rep("Toaster",3),rep("Phone", 2), rep("Radio",3), rep("Stereo", 2)))

df2 = data.frame(CustomerId=c(2,4,6, 8, 10),State=c(rep("Alabama",2),rep("Ohio",1),   rep("Cal", 2)),
             like=c("sing", 'hiking', "pingpong", 'hiking', "sing"))

df3 = merge(df1, df2, by.x=c("CustomerId", "Hobby"), by.y=c("CustomerId", "like"))

Assuming df1$Hobby and df2$like mean the same thing.

Number of processors/cores in command line

On newer kernels you could also possibly use the the /sys/devices/system/cpu/ interface to get a bit more information:

$ ls /sys/devices/system/cpu/
cpu0  cpufreq  kernel_max  offline  possible  present  release
cpu1  cpuidle  modalias    online   power     probe    uevent
$ cat /sys/devices/system/cpu/kernel_max 
255
$ cat /sys/devices/system/cpu/offline 
2-63
$ cat /sys/devices/system/cpu/possible 
0-63
$ cat /sys/devices/system/cpu/present 
0-1
$ cat /sys/devices/system/cpu/online 
0-1

See the official docs for more information on what all these mean.

How do I concatenate two text files in PowerShell?

Do not use >; it messes up the character encoding. Use:

Get-Content files.* | Set-Content newfile.file

Check string for palindrome

Considering not letters in the words

public static boolean palindromeWords(String s ){

        int left=0;
        int right=s.length()-1;

        while(left<=right){

            while(left<right && !Character.isLetter(s.charAt(left))){
                left++;
            }
            while(right>0 && !Character.isLetter(s.charAt(right))){
                right--;
            }

            if((s.charAt(left++))!=(s.charAt(right--))){
                return false;
            }
        }
        return true;
    }

———

@Test
public void testPalindromeWords(){
    assertTrue(StringExercise.palindromeWords("ece"));
    assertTrue(StringExercise.palindromeWords("kavak"));
    assertFalse(StringExercise.palindromeWords("kavakdf"));
    assertTrue(StringExercise.palindromeWords("akka"));
    assertTrue(StringExercise.palindromeWords("??e@@c_--e"));
}

Is there any way to call a function periodically in JavaScript?

yes - take a look at setInterval and setTimeout for executing code at certain times. setInterval would be the one to use to execute code periodically.

See a demo and answer here for usage

Adding local .aar files to Gradle build using "flatDirs" is not working

In my case, I just put the aar file in libs, and add

dependencies { ... api fileTree(dir: 'libs', include: ['*.aar']) ... }

in build.gradle and it works. I think it is similar with default generated dependency:

implementation fileTree(dir: 'libs', include: ['*.jar'])

what is difference between success and .done() method of $.ajax

In short, decoupling success callback function from the ajax function so later you can add your own handlers without modifying the original code (observer pattern).

Please find more detailed information from here: https://stackoverflow.com/a/14754681/1049184

Maximize a window programmatically and prevent the user from changing the windows state

Change the property WindowState to System.Windows.Forms.FormWindowState.Maximized, in some cases if the older answers doesn't works.

So the window will be maximized, and the other parts are in the other answers.

Find and extract a number from a string

use regular expression ...

Regex re = new Regex(@"\d+");
Match m = re.Match("test 66");

if (m.Success)
{
    Console.WriteLine(string.Format("RegEx found " + m.Value + " at position " + m.Index.ToString()));
}
else
{
    Console.WriteLine("You didn't enter a string containing a number!");
}

Adding subscribers to a list using Mailchimp's API v3

Based on the List Members Instance docs, the easiest way is to use a PUT request which according to the docs either "adds a new list member or updates the member if the email already exists on the list".

Furthermore apikey is definitely not part of the json schema and there's no point in including it in your json request.

Also, as noted in @TooMuchPete's comment, you can use CURLOPT_USERPWD for basic http auth as illustrated in below.

I'm using the following function to add and update list members. You may need to include a slightly different set of merge_fields depending on your list parameters.

$data = [
    'email'     => '[email protected]',
    'status'    => 'subscribed',
    'firstname' => 'john',
    'lastname'  => 'doe'
];

syncMailchimp($data);

function syncMailchimp($data) {
    $apiKey = 'your api key';
    $listId = 'your list id';

    $memberId = md5(strtolower($data['email']));
    $dataCenter = substr($apiKey,strpos($apiKey,'-')+1);
    $url = 'https://' . $dataCenter . '.api.mailchimp.com/3.0/lists/' . $listId . '/members/' . $memberId;

    $json = json_encode([
        'email_address' => $data['email'],
        'status'        => $data['status'], // "subscribed","unsubscribed","cleaned","pending"
        'merge_fields'  => [
            'FNAME'     => $data['firstname'],
            'LNAME'     => $data['lastname']
        ]
    ]);

    $ch = curl_init($url);

    curl_setopt($ch, CURLOPT_USERPWD, 'user:' . $apiKey);
    curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_TIMEOUT, 10);
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PUT');
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $json);                                                                                                                 

    $result = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    return $httpCode;
}

How to add label in chart.js for pie chart

It is not necessary to use another library like newChart or use other people's pull requests to pull this off. All you have to do is define an options object and add the label wherever and however you want it in the tooltip.

var optionsPie = {
    tooltipTemplate: "<%= label %> - <%= value %>"
}

If you want the tooltip to be always shown you can make some other edits to the options:

 var optionsPie = {
        tooltipEvents: [],
        showTooltips: true,
        onAnimationComplete: function() {
            this.showTooltip(this.segments, true);
        },
        tooltipTemplate: "<%= label %> - <%= value %>"
    }

In your data items, you have to add the desired label property and value and that's all.

data = [
    {
        value: 480000,
        color:"#F7464A",
        highlight: "#FF5A5E",
        label: "Tobacco"
    }
];

Now, all you have to do is pass the options object after the data to the new Pie like this: new Chart(ctx).Pie(data,optionsPie) and you are done.

This probably works best for pies which are not very small in size.

Pie chart with labels

Java int to String - Integer.toString(i) vs new Integer(i).toString()

Integer.toString calls the static method in the class Integer. It does not need an instance of Integer.

If you call new Integer(i) you create an instance of type Integer, which is a full Java object encapsulating the value of your int. Then you call the toString method on it to ask it to return a string representation of itself.

If all you want is to print an int, you'd use the first one because it's lighter, faster and doesn't use extra memory (aside from the returned string).

If you want an object representing an integer value—to put it inside a collection for example—you'd use the second one, since it gives you a full-fledged object to do all sort of things that you cannot do with a bare int.

Broadcast receiver for checking internet connection in android app

First of all we will make a class that will check the connectivity of the network state. So lets create a class :

public class AppStatus {
    private static AppStatus instance = new AppStatus();
    static Context context;
    ConnectivityManager connectivityManager;
    NetworkInfo wifiInfo, mobileInfo;
    boolean connected = false;

    public static AppStatus getInstance(Context ctx) {
        context = ctx.getApplicationContext();
        return instance;
    }

    public boolean isOnline() {
        try {
            connectivityManager = (ConnectivityManager) context
                    .getSystemService(Context.CONNECTIVITY_SERVICE);

            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
            connected = networkInfo != null && networkInfo.isAvailable() &&
                    networkInfo.isConnected();
            return connected;


        } catch (Exception e) {
            System.out.println("CheckConnectivity Exception: " + e.getMessage());
            Log.v("connectivity", e.toString());
        }
        return connected;
    }
}

Now Make a new Broadcast receiver class :

public class ConnectivityReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (AppStatus.getInstance(context).isOnline()) {

            Intent intent1=new Intent(context,DisplayAct.class);
            intent1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(intent1);




        } else {

            Toast.makeText(context, "Please !! Make your network ON", Toast.LENGTH_SHORT).show();

        }
    }
}

and Now register your broadcast receiver on manifest:

<receiver android:name=".ConnectivityReceiver">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
            </intent-filter>
        </receiver>

Getting a Request.Headers value

Firstly you don't do this in your view. You do it in the controller and return a view model to the view so that the view doesn't need to care about custom HTTP headers but just displaying data on the view model:

public ActionResult Index()
{
    var xyzComponent = Request.Headers["xyzComponent"];
    var model = new MyModel 
    {
        IsCustomHeaderSet = (xyzComponent != null)
    }
    return View(model);
}

SQL Query for Student mark functionality

My attempt - I'd start with the max mark and build from there

Schema:

CREATE TABLE Student (
  StudentId int,
  Name nvarchar(30),
  Details nvarchar(30)
)
CREATE TABLE Subject (
  SubjectId int,
  Name nvarchar(30)
)
CREATE TABLE Marks (
  StudentId int,
  SubjectId int,
  Mark int
)

Data:

INSERT INTO Student (StudentId, Name, Details) 
VALUES (1,'Alfred','AA'), (2,'Betty','BB'), (3,'Chris','CC')

INSERT INTO Subject (SubjectId, Name)
VALUES (1,'Maths'), (2, 'Science'), (3, 'English')

INSERT INTO Marks (StudentId, SubjectId, Mark)
VALUES 
(1,1,61),(1,2,75),(1,3,87),
(2,1,82),(2,2,64),(2,3,77),
(3,1,82),(3,2,83),(3,3,67)
GO

My query would have been:

;WITH MaxMarks AS (
  SELECT SubjectId, MAX(Mark) as MaxMark
    FROM Marks
    GROUP BY SubjectId
 )
SELECT s.Name as [StudentName], sub.Name AS [SubjectName],m.Mark
FROM MaxMarks mm
INNER JOIN Marks m 
ON m.SubjectId = mm.SubjectId 
AND m.Mark = mm.MaxMark
INNER JOIN Student s
ON s.StudentId = m.StudentId
INNER JOIN Subject sub
ON sub.SubjectId = mm.SubjectId

SQL Fiddle Example

  1. Find the max mark for each subject
  2. Join Marks, Student and Subject to find the relevant details of that highest mark

This also take care of duplicate students with the highest mark

Results:

STUDENTNAME SUBJECTNAME     MARK
Alfred  English     87
Betty   Maths           82
Chris   Maths           82
Chris   Science     83

How do I pass an object from one activity to another on Android?

This answer is specific to situations where the objects to be passed has nested class structure. With nested class structure, making it Parcelable or Serializeable is a bit tedious. And, the process of serialising an object is not efficient on Android. Consider the example below,

class Myclass    {
  int a;
  class SubClass    {
       int b;
  }
}

With Google's GSON library, you can directly parse an object into a JSON formatted String and convert it back to the object format after usage. For example,

MyClass src = new MyClass();
Gson gS = new Gson();
String target = gS.toJson(src); // Converts the object to a JSON String

Now you can pass this String across activities as a StringExtra with the activity intent.

Intent i = new Intent(FromActivity.this, ToActivity.class);
i.putExtra("MyObjectAsString", target);

Then in the receiving activity, create the original object from the string representation.

String target = getIntent().getStringExtra("MyObjectAsString");
MyClass src = gS.fromJson(target, MyClass.class); // Converts the JSON String to an Object

It keeps the original classes clean and reusable. Above of all, if these class objects are created from the web as JSON objects, then this solution is very efficient and time saving.

UPDATE


While the above explained method works for most situations, for obvious performance reasons, do not rely on Android's bundled-extra system to pass objects around. There are a number of solutions makes this process flexible and efficient, here are a few. Each has its own pros and cons.

  1. Eventbus
  2. Otto

failed to load ad : 3

One new and update answer: Many apps that were removed this October(2018) for the lack of Privacy Policy are unable to receive ads after they get back in Play Store. You must use this form to request a "reset" for that app's ads. https://support.google.com/admob/contact/appeal_policy_violation

Took me a few days to realize and find the answer. Hope you get your ads back.

Routing HTTP Error 404.0 0x80070002

The solution suggested

<system.webServer>
  <modules runAllManagedModulesForAllRequests="true" >
    <remove name="UrlRoutingModule"/>    
  </modules>
</system.webServer>

works, but can degrade performance and can even cause errors, because now all registered HTTP modules run on every request, not just managed requests (e.g. .aspx). This means modules will run on every .jpg .gif .css .html .pdf etc.

A more sensible solution is to include this in your web.config:

<system.webServer>
  <modules>
    <remove name="UrlRoutingModule-4.0" />
    <add name="UrlRoutingModule-4.0" type="System.Web.Routing.UrlRoutingModule" preCondition="" />
  </modules>
</system.webServer>

Credit for his goes to Colin Farr. Check-out his post about this topic at http://www.britishdeveloper.co.uk/2010/06/dont-use-modules-runallmanagedmodulesfo.html.

Using LINQ to group by multiple properties and sum

Use the .Select() after grouping:

var agencyContracts = _agencyContractsRepository.AgencyContracts
    .GroupBy(ac => new
                   {
                       ac.AgencyContractID, // required by your view model. should be omited
                                            // in most cases because group by primary key
                                            // makes no sense.
                       ac.AgencyID,
                       ac.VendorID,
                       ac.RegionID
                   })
    .Select(ac => new AgencyContractViewModel
                   {
                       AgencyContractID = ac.Key.AgencyContractID,
                       AgencyId = ac.Key.AgencyID,
                       VendorId = ac.Key.VendorID,
                       RegionId = ac.Key.RegionID,
                       Amount = ac.Sum(acs => acs.Amount),
                       Fee = ac.Sum(acs => acs.Fee)
                   });

Merge, update, and pull Git branches without using checkouts

I wrote a shell function for a similar use case I encounter daily on projects. This is basically a shortcut for keeping local branches up to date with a common branch like develop before opening a PR, etc.

Posting this even though you don't want to use checkout, in case others don't mind that constraint.

glmh ("git pull and merge here") will automatically checkout branchB, pull the latest, re-checkout branchA, and merge branchB.

Doesn't address the need to keep a local copy of branchA, but could easily be modified to do so by adding a step before checking out branchB. Something like...

git branch ${branchA}-no-branchB ${branchA}

For simple fast-forward merges, this skips to the commit message prompt.

For non fast-forward merges, this places your branch in the conflict resolution state (you likely need to intervene).

To setup, add to .bashrc or .zshrc, etc:

glmh() {
    branchB=$1
    [ $# -eq 0 ] && { branchB="develop" }
    branchA="$(git branch | grep '*' | sed 's/* //g')"
    git checkout ${branchB} && git pull
    git checkout ${branchA} && git merge ${branchB} 
}

Usage:

# No argument given, will assume "develop"
> glmh

# Pass an argument to pull and merge a specific branch
> glmh your-other-branch

Note: This is not robust enough to hand-off of args beyond branch name to git merge

Install a Nuget package in Visual Studio Code

Nuget Gallery provides a GUI similar to the full Visual Studio. See below.

enter image description here

How To Use:

  1. Install Nuget Gallery from extension marketplace.
  2. Launch from the menu bar View > Command Palette or ??P (Ctrl+Shift+P on Windows and Linux). Type Nuget: Open Gallery.
  3. The GUI above is displayed. You can filter just like in regular Visual Studio.
  4. Make sure the .csproj file checkbox is selected, select version from dropdown, and click install button.

UPDATE

Earlier versions, as noted in the comments, had an issue where the .csproj checkbox was not visible when a package in the csproj file was missing a version number like below.

<PackageReference Include="Microsoft.AspNetCore.App" />

This has been fixed in newer versions of the extension so if you have an older version with this issue, please update it to the latest version.

Getting date format m-d-Y H:i:s.u from milliseconds

php.net says:

Microseconds (added in PHP 5.2.2). Note that date() will always generate 000000 since it takes an integer parameter, whereas DateTime::format() does support microseconds if DateTime was created with microseconds.

So use as simple:

$micro_date = microtime();
$date_array = explode(" ",$micro_date);
$date = date("Y-m-d H:i:s",$date_array[1]);
echo "Date: $date:" . $date_array[0]."<br>";

Recommended and use dateTime() class from referenced:

$t = microtime(true);
$micro = sprintf("%06d",($t - floor($t)) * 1000000);
$d = new DateTime( date('Y-m-d H:i:s.'.$micro, $t) );

print $d->format("Y-m-d H:i:s.u"); // note at point on "u"

Note u is microseconds (1 seconds = 1000000 µs).

Another example from php.net:

$d2=new DateTime("2012-07-08 11:14:15.889342");

Reference of dateTime() on php.net

I've answered on question as short and simplify to author. Please see for more information to author: getting date format m-d-Y H:i:s.u from milliseconds

Why are only a few video games written in Java?

A large reason is that video games require direct knowledge of the hardware underneath, often times, and there really is no great implementation for many architectures. It's the knowledge of the underlying hardware architecture that allows developers to squeeze every ounce of performance out of a gaming system. Why would you take the time to port Java to a gaming platform, and then write a game on top of that port when you could just write the game?

edit: this is to say that it's more than a "speed" or "don't have the right libraries" issue. Those two things go hand-in-hand with this, but it's more a matter of "how do I make a system like the cell b.e. run my java code? there aren't really any good java compilers that can manage the pipelines and vectors like i need.."

How to redirect to an external URL in Angular2?

The solution, as Dennis Smolek said, is dead simple. Set window.location.href to the URL you want to switch to and it just works.

For example, if you had this method in your component's class file (controller):

goCNN() {
    window.location.href='http://www.cnn.com/';
}

Then you could call it quite simply with the appropriate (click) call on a button (or whatever) in your template:

<button (click)="goCNN()">Go to CNN</button>

Remove rows with all or some NAs (missing values) in data.frame

Another option if you want greater control over how rows are deemed to be invalid is

final <- final[!(is.na(final$rnor)) | !(is.na(rawdata$cfam)),]

Using the above, this:

             gene hsap mmul mmus rnor cfam
1 ENSG00000208234    0   NA   NA   NA   2
2 ENSG00000199674    0   2    2    2    2
3 ENSG00000221622    0   NA   NA   2   NA
4 ENSG00000207604    0   NA   NA   1    2
5 ENSG00000207431    0   NA   NA   NA   NA
6 ENSG00000221312    0   1    2    3    2

Becomes:

             gene hsap mmul mmus rnor cfam
1 ENSG00000208234    0   NA   NA   NA   2
2 ENSG00000199674    0   2    2    2    2
3 ENSG00000221622    0   NA   NA   2   NA
4 ENSG00000207604    0   NA   NA   1    2
6 ENSG00000221312    0   1    2    3    2

...where only row 5 is removed since it is the only row containing NAs for both rnor AND cfam. The boolean logic can then be changed to fit specific requirements.

Java SE 6 vs. JRE 1.6 vs. JDK 1.6 - What do these mean?

This might help someone:

I am installing the latest Java on my system for development, and currently it's Java SE 7. Now, let's dive into this "madness", as you put it...

All of these are the same (when developers are talking about Java for development):

  • Java SE 7
  • Java SE v1.7.0
  • Java SE Development Kit 7

Starting with Java v1.5:

  • v5 = v1.5.
  • v6 = v1.6.
  • v7 = v1.7.

And we can assume this will remain for future versions.

Next, for developers, download JDK, not JRE.

JDK will contain JRE. If you need JDK and JRE, get JDK. Both will be installed from the single JDK install, as you will see below.

As someone above mentioned:

  • JDK = Java Development Kit (developers need this, this is you if you code in Java)
  • JRE = Java Runtime Environment (users need this, this is every computer user today)
  • Java SE = Java Standard Edition

Here's the step by step links I followed (one step leads to the next, this is all for a single download) to download Java for development (JDK):

  1. Visit "Java SE Downloads": http://www.oracle.com/technetwork/java/javase/downloads/index.html
  2. Click "JDK Download" and visit "Java SE Development Kit 7 Downloads": http://www.oracle.com/technetwork/java/javase/downloads/java-se-jdk-7-download-432154.html (note that following the link from step #1 will take you to a different link as JDK 1.7 updates, later versions, are now out)
  3. Accept agreement :)
  4. Click "Java SE Development Kit 7 (Windows x64)": http://download.oracle.com/otn-pub/java/jdk/7/jdk-7-windows-x64.exe (for my 64-bit Windows 7 system)
  5. You are now downloading (hopefully the latest) JDK for your system! :)

Keep in mind the above links are for reference purposes only, to show you the step by step method of what it takes to download the JDK.

And install with default settings to:

  • “C:\Program Files\Java\jdk1.7.0\” (JDK)
  • “C:\Program Files\Java\jre7\” (JRE) <--- why did it ask a new install folder? it's JRE!

Remember from above that JDK contains JRE, which makes sense if you know what they both are. Again, see above.

After your install, double check “C:\Program Files\Java” to see both these folders. Now you know what they are and why they are there.

I know I wrote this for newbies, but I enjoy knowing things in full detail, so I hope this helps.

Creating a byte array from a stream

Just want to point out that in case you have a MemoryStream you already have memorystream.ToArray() for that.

Also, if you are dealing with streams of unknown or different subtypes and you can receive a MemoryStream, you can relay on said method for those cases and still use the accepted answer for the others, like this:

public static byte[] StreamToByteArray(Stream stream)
{
    if (stream is MemoryStream)
    {
        return ((MemoryStream)stream).ToArray();                
    }
    else
    {
        // Jon Skeet's accepted answer 
        return ReadFully(stream);
    }
}

How do I format date in jQuery datetimepicker?

For example, I get date/time in format Spanish.

$('#timePicker').datetimepicker({
    defaultDate: new Date(),
    format:'DD/MM/YYYY HH:mm'
});

Android - get children inside a View?

You can always access child views via View.findViewById() http://developer.android.com/reference/android/view/View.html#findViewById(int).

For example, within an activity / view:

...
private void init() {
  View child1 = findViewById(R.id.child1);
}
...

or if you have a reference to a view:

...
private void init(View root) {
  View child2 = root.findViewById(R.id.child2);
}

BULK INSERT with identity (auto-increment) column

Add an id column to the csv file and leave it blank:

id,Name,Address
,name1,addr test 1
,name2,addr test 2

Remove KEEPIDENTITY keyword from query:

BULK INSERT Employee  FROM 'path\tempFile.csv ' 
WITH (FIRSTROW = 2,FIELDTERMINATOR = ',' , ROWTERMINATOR = '\n');

The id identity field will be auto-incremented.

If you assign values to the id field in the csv, they'll be ignored unless you use the KEEPIDENTITY keyword, then they'll be used instead of auto-increment.

How do I parse JSON in Android?

  1. Writing JSON Parser Class

    public class JSONParser {
    
        static InputStream is = null;
        static JSONObject jObj = null;
        static String json = "";
    
        // constructor
        public JSONParser() {}
    
        public JSONObject getJSONFromUrl(String url) {
    
            // Making HTTP request
            try {
                // defaultHttpClient
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
    
                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
    
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
    
            try {
                BufferedReader reader = new BufferedReader(new InputStreamReader(
                        is, "iso-8859-1"), 8);
                StringBuilder sb = new StringBuilder();
                String line = null;
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                }
                is.close();
                json = sb.toString();
            } catch (Exception e) {
                Log.e("Buffer Error", "Error converting result " + e.toString());
            }
    
            // try parse the string to a JSON object
            try {
                jObj = new JSONObject(json);
            } catch (JSONException e) {
                Log.e("JSON Parser", "Error parsing data " + e.toString());
            }
    
            // return JSON String
            return jObj;
    
        }
    }
    
  2. Parsing JSON Data
    Once you created parser class next thing is to know how to use that class. Below i am explaining how to parse the json (taken in this example) using the parser class.

    2.1. Store all these node names in variables: In the contacts json we have items like name, email, address, gender and phone numbers. So first thing is to store all these node names in variables. Open your main activity class and declare store all node names in static variables.

    // url to make request
    private static String url = "http://api.9android.net/contacts";
    
    // JSON Node names
    private static final String TAG_CONTACTS = "contacts";
    private static final String TAG_ID = "id";
    private static final String TAG_NAME = "name";
    private static final String TAG_EMAIL = "email";
    private static final String TAG_ADDRESS = "address";
    private static final String TAG_GENDER = "gender";
    private static final String TAG_PHONE = "phone";
    private static final String TAG_PHONE_MOBILE = "mobile";
    private static final String TAG_PHONE_HOME = "home";
    private static final String TAG_PHONE_OFFICE = "office";
    
    // contacts JSONArray
    JSONArray contacts = null;
    

    2.2. Use parser class to get JSONObject and looping through each json item. Below i am creating an instance of JSONParser class and using for loop i am looping through each json item and finally storing each json data in variable.

    // Creating JSON Parser instance
    JSONParser jParser = new JSONParser();
    
    // getting JSON string from URL
    JSONObject json = jParser.getJSONFromUrl(url);
    
        try {
        // Getting Array of Contacts
        contacts = json.getJSONArray(TAG_CONTACTS);
    
        // looping through All Contacts
        for(int i = 0; i < contacts.length(); i++){
            JSONObject c = contacts.getJSONObject(i);
    
            // Storing each json item in variable
            String id = c.getString(TAG_ID);
            String name = c.getString(TAG_NAME);
            String email = c.getString(TAG_EMAIL);
            String address = c.getString(TAG_ADDRESS);
            String gender = c.getString(TAG_GENDER);
    
            // Phone number is agin JSON Object
            JSONObject phone = c.getJSONObject(TAG_PHONE);
            String mobile = phone.getString(TAG_PHONE_MOBILE);
            String home = phone.getString(TAG_PHONE_HOME);
            String office = phone.getString(TAG_PHONE_OFFICE);
    
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
    

Add ripple effect to my button with button background color?

A simple approach is to set a view theme as outlined here.

some_view.xml

<ImageView
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:background="?attr/selectableItemBackgroundBorderless"
   android:focusable="true"
   android:src="@drawable/up_arrow"
   android:theme="@style/SomeButtonTheme"/>

some_style.xml

<style name="SomeButtonTheme" >
   <item name="colorControlHighlight">@color/someColor</item>
</style>

What is 'Context' on Android?

Context is a reference to the current object as this. Also context allows access to information about the application environment.

Collectors.toMap() keyMapper -- more succinct expression?

List<Person> roster = ...;

Map<String, Person> map = 
    roster
        .stream()
        .collect(
            Collectors.toMap(p -> p.getLast(), p -> p)
        );

that would be the translation, but i havent run this or used the API. most likely you can substitute p -> p, for Function.identity(). and statically import toMap(...)

How many values can be represented with n bits?

There's an easier way to think about this. Start with 1 bit. This can obviously represent 2 values (0 or 1). What happens when we add a bit? We can now represent twice as many values: the values we could represent before with a 0 appended and the values we could represent before with a 1 appended.

So the the number of values we can represent with n bits is just 2^n (2 to the power n)

Excel VBA Run Time Error '424' object required

Private Sub CommandButton1_Click()

    Workbooks("Textfile_Receiving").Sheets("menu").Range("g1").Value = PROV.Text
    Workbooks("Textfile_Receiving").Sheets("menu").Range("g2").Value = MUN.Text
    Workbooks("Textfile_Receiving").Sheets("menu").Range("g3").Value = CAT.Text
    Workbooks("Textfile_Receiving").Sheets("menu").Range("g4").Value = Label5.Caption

    Me.Hide

    Run "filename"

End Sub

Private Sub MUN_Change()
    Dim r As Integer
    r = 2

    While Range("m" & CStr(r)).Value <> ""
        If Range("m" & CStr(r)).Value = MUN.Text Then
        Label5.Caption = Range("n" & CStr(r)).Value
        End If
        r = r + 1
    Wend

End Sub

Private Sub PROV_Change()
    If PROV.Text = "LAGUNA" Then
        MUN.Text = ""
        MUN.RowSource = "Menu!M26:M56"
    ElseIf PROV.Text = "CAVITE" Then
        MUN.Text = ""
        MUN.RowSource = "Menu!M2:M25"
    ElseIf PROV.Text = "QUEZON" Then
        MUN.Text = ""
        MUN.RowSource = "Menu!M57:M97"
    End If
End Sub

Hide vertical scrollbar in <select> element

I know this thread is somewhat old, but there are a lot of really hacky answers on here, so I'd like to provide something that is a lot simpler and a lot cleaner:

select {
    overflow-y: auto;
}

As you can see in this fiddle, this solution provides you with flexibility if you don't know the exact number of select options you are going to have. It hides the scrollbar in the case that you don't need it without hiding possible extra option elements in the other case. Don't do all this hacky overlapping div stuff. It just makes for unreadable markup.

How to resize superview to fit all subviews with autolayout?

This can be done for a normal subview inside a larger UIView, but it doesn't work automatically for headerViews. The height of a headerView is determined by what's returned by tableView:heightForHeaderInSection: so you have to calculate the height based on the height of the UILabel plus space for the UIButton and any padding you need. You need to do something like this:

-(CGFloat)tableView:(UITableView *)tableView 
          heightForHeaderInSection:(NSInteger)section {
    NSString *s = self.headeString[indexPath.section];
    CGSize size = [s sizeWithFont:[UIFont systemFontOfSize:17] 
                constrainedToSize:CGSizeMake(281, CGFLOAT_MAX)
                    lineBreakMode:NSLineBreakByWordWrapping];
    return size.height + 60;
}

Here headerString is whatever string you want to populate the UILabel, and the 281 number is the width of the UILabel (as setup in Interface Builder)

PHP and MySQL Select a Single Value

You do this by using mysqli_fetch_field method.

session_start();
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
$name = $_GET["username"];
$sql = "SELECT 'id' FROM Users WHERE username='$name' limit 1";
$result = mysqli_query($link, $sql);
if ($result !== false) {
    $value = mysqli_fetch_field($result);
    $_SESSION['myid'] = $value;
}

Note: you can do that by using mysql_fetch_field() method as well, but it will be deprecated in php v5.5

C# static class why use?

Static classes can be useful in certain situations, but there is a potential to abuse and/or overuse them, like most language features.

As Dylan Smith already mentioned, the most obvious case for using a static class is if you have a class with only static methods. There is no point in allowing developers to instantiate such a class.

The caveat is that an overabundance of static methods may itself indicate a flaw in your design strategy. I find that when you are creating a static function, its a good to ask yourself -- would it be better suited as either a) an instance method, or b) an extension method to an interface. The idea here is that object behaviors are usually associated with object state, meaning the behavior should belong to the object. By using a static function you are implying that the behavior shouldn't belong to any particular object.

Polymorphic and interface driven design are hindered by overusing static functions -- they cannot be overriden in derived classes nor can they be attached to an interface. Its usually better to have your 'helper' functions tied to an interface via an extension method such that all instances of the interface have access to that shared 'helper' functionality.

One situation where static functions are definitely useful, in my opinion, is in creating a .Create() or .New() method to implement logic for object creation, for instance when you want to proxy the object being created,

public class Foo
{
    public static Foo New(string fooString)
    {
        ProxyGenerator generator = new ProxyGenerator();

        return (Foo)generator.CreateClassProxy
             (typeof(Foo), new object[] { fooString }, new Interceptor()); 
    }

This can be used with a proxying framework (like Castle Dynamic Proxy) where you want to intercept / inject functionality into an object, based on say, certain attributes assigned to its methods. The overall idea is that you need a special constructor because technically you are creating a copy of the original instance with special added functionality.

How to read json file into java with simple JSON library

Hope this example helps too

I have done java coding in a similar way for the below json array example as follows :

following is the json data format : stored as "EMPJSONDATA.json"

[{"EMPNO":275172,"EMP_NAME":"Rehan","DOB":"29-02-1992","DOJ":"10-06-2013","ROLE":"JAVA DEVELOPER"},

{"EMPNO":275173,"EMP_NAME":"G.K","DOB":"10-02-1992","DOJ":"11-07-2013","ROLE":"WINDOWS ADMINISTRATOR"},

{"EMPNO":275174,"EMP_NAME":"Abiram","DOB":"10-04-1992","DOJ":"12-08-2013","ROLE":"PROJECT ANALYST"}

{"EMPNO":275174,"EMP_NAME":"Mohamed Mushi","DOB":"10-04-1992","DOJ":"12-08-2013","ROLE":"PROJECT ANALYST"}]

public class Jsonminiproject {

public static void main(String[] args) {

      JSONParser parser = new JSONParser();

    try {
        JSONArray a = (JSONArray) parser.parse(new FileReader("F:/JSON DATA/EMPJSONDATA.json"));
        for (Object o : a)
        {
            JSONObject employee = (JSONObject) o;

            Long no = (Long) employee.get("EMPNO");
            System.out.println("Employee Number : " + no);

            String st = (String) employee.get("EMP_NAME");
            System.out.println("Employee Name : " + st);

            String dob = (String) employee.get("DOB");
            System.out.println("Employee DOB : " + dob);

            String doj = (String) employee.get("DOJ");
            System.out.println("Employee DOJ : " + doj);

            String role = (String) employee.get("ROLE");
            System.out.println("Employee Role : " + role);

            System.out.println("\n");

        }


    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }




}

}

How do you detect Credit card type based on number?

// abobjects.com, parvez ahmad ab bulk mailer
use below script

function isValidCreditCard2(type, ccnum) {
       if (type == "Visa") {
          // Visa: length 16, prefix 4, dashes optional.
          var re = /^4\d{3}?\d{4}?\d{4}?\d{4}$/;
       } else if (type == "MasterCard") {
          // Mastercard: length 16, prefix 51-55, dashes optional.
          var re = /^5[1-5]\d{2}?\d{4}?\d{4}?\d{4}$/;
       } else if (type == "Discover") {
          // Discover: length 16, prefix 6011, dashes optional.
          var re = /^6011?\d{4}?\d{4}?\d{4}$/;
       } else if (type == "AmEx") {
          // American Express: length 15, prefix 34 or 37.
          var re = /^3[4,7]\d{13}$/;
       } else if (type == "Diners") {
          // Diners: length 14, prefix 30, 36, or 38.
          var re = /^3[0,6,8]\d{12}$/;
       }
       if (!re.test(ccnum)) return false;
       return true;
       /*
       // Remove all dashes for the checksum checks to eliminate negative numbers
       ccnum = ccnum.split("-").join("");
       // Checksum ("Mod 10")
       // Add even digits in even length strings or odd digits in odd length strings.
       var checksum = 0;
       for (var i=(2-(ccnum.length % 2)); i<=ccnum.length; i+=2) {
          checksum += parseInt(ccnum.charAt(i-1));
       }
       // Analyze odd digits in even length strings or even digits in odd length strings.
       for (var i=(ccnum.length % 2) + 1; i<ccnum.length; i+=2) {
          var digit = parseInt(ccnum.charAt(i-1)) * 2;
          if (digit < 10) { checksum += digit; } else { checksum += (digit-9); }
       }
       if ((checksum % 10) == 0) return true; else return false;
       */

    }
jQuery.validator.addMethod("isValidCreditCard", function(postalcode, element) { 
    return isValidCreditCard2($("#cardType").val(), $("#cardNum").val()); 

}, "<br>credit card is invalid");


     Type</td>
                                          <td class="text">&nbsp; <form:select path="cardType" cssclass="fields" style="border: 1px solid #D5D5D5;padding: 0px 0px 0px 0px;width: 130px;height: 22px;">
                                              <option value="SELECT">SELECT</option>
                                              <option value="MasterCard">Mastercard</option>
                                              <option value="Visa">Visa</option>
                                               <option value="AmEx">American Express</option>
                                              <option value="Discover">Discover</option>
                                            </form:select> <font color="#FF0000">*</font> 

$("#signupForm").validate({

    rules:{
       companyName:{required: true},
       address1:{required: true},
       city:{required: true},
       state:{required: true},
       zip:{required: true},
       country:{required: true},
       chkAgree:{required: true},
       confPassword:{required: true},
       lastName:{required: true},
       firstName:{required: true},
       ccAddress1:{required: true},
       ccZip:{         
           postalcode : true
       },
       phone:{required: true},
       email:{
           required: true,
           email: true
           },
       userName:{
           required: true,
           minlength: 6
           },
       password:{
           required: true,
           minlength: 6
           },          
       cardNum:{           
            isValidCreditCard : true
       },

How to make Unicode charset in cmd.exe by default?

Open an elevated Command Prompt (run cmd as administrator). query your registry for available TT fonts to the console by:

    REG query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont"

You'll see an output like :

    0    REG_SZ    Lucida Console
    00    REG_SZ    Consolas
    936    REG_SZ    *???
    932    REG_SZ    *MS ????

Now we need to add a TT font that supports the characters you need like Courier New, we do this by adding zeros to the string name, so in this case the next one would be "000" :

    REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont" /v 000 /t REG_SZ /d "Courier New"

Now we implement UTF-8 support:

    REG ADD HKCU\Console /v CodePage /t REG_DWORD /d 65001 /f

Set default font to "Courier New":

    REG ADD HKCU\Console /v FaceName /t REG_SZ /d "Courier New" /f

Set font size to 20 :

    REG ADD HKCU\Console /v FontSize /t REG_DWORD /d 20 /f

Enable quick edit if you like :

    REG ADD HKCU\Console /v QuickEdit /t REG_DWORD /d 1 /f

Converting an array to a function arguments list

A very readable example from another post on similar topic:

var args = [ 'p0', 'p1', 'p2' ];

function call_me (param0, param1, param2 ) {
    // ...
}

// Calling the function using the array with apply()
call_me.apply(this, args);

And here a link to the original post that I personally liked for its readability

Finding all positions of substring in a larger string in C#

I found this example and incorporated it into a function:

    public static int solution1(int A, int B)
    {
        // Check if A and B are in [0...999,999,999]
        if ( (A >= 0 && A <= 999999999) && (B >= 0 && B <= 999999999))
        {
            if (A == 0 && B == 0)
            {
                return 0;
            }
            // Make sure A < B
            if (A < B)
            {                    
                // Convert A and B to strings
                string a = A.ToString();
                string b = B.ToString();
                int index = 0;

                // See if A is a substring of B
                if (b.Contains(a))
                {
                    // Find index where A is
                    if (b.IndexOf(a) != -1)
                    {                            
                        while ((index = b.IndexOf(a, index)) != -1)
                        {
                            Console.WriteLine(A + " found at position " + index);
                            index++;
                        }
                        Console.ReadLine();
                        return b.IndexOf(a);
                    }
                    else
                        return -1;
                }
                else
                {
                    Console.WriteLine(A + " is not in " + B + ".");
                    Console.ReadLine();

                    return -1;
                }
            }
            else
            {
                Console.WriteLine(A + " must be less than " + B + ".");
               // Console.ReadLine();

                return -1;
            }                
        }
        else
        {
            Console.WriteLine("A or B is out of range.");
            //Console.ReadLine();

            return -1;
        }
    }

    static void Main(string[] args)
    {
        int A = 53, B = 1953786;
        int C = 78, D = 195378678;
        int E = 57, F = 153786;

        solution1(A, B);
        solution1(C, D);
        solution1(E, F);

        Console.WriteLine();
    }

Returns:

53 found at position 2

78 found at position 4
78 found at position 7

57 is not in 153786

How to turn off magic quotes on shared hosting?

If you're running PHP 5.3+ this will do the trick, place it at the topmost of your page:

if (get_magic_quotes_gpc() === 1)
{
    $_GET = json_decode(stripslashes(json_encode($_GET, JSON_HEX_APOS)), true);
    $_POST = json_decode(stripslashes(json_encode($_POST, JSON_HEX_APOS)), true);
    $_COOKIE = json_decode(stripslashes(json_encode($_COOKIE, JSON_HEX_APOS)), true);
    $_REQUEST = json_decode(stripslashes(json_encode($_REQUEST, JSON_HEX_APOS)), true);
}

Handles keys, values and multi-dimensional arrays.

DBCC CHECKIDENT Sets Identity to 0

It seems ridiculous that you can't set/reset an identity column with a single command to cover both cases of whether or not the table has had records inserted. I couldn't understand the behavior I was experiencing until I stumbled across this question on SO!

My solution (ugly but works) is to explicitly check the sys.identity_columns.last_value table (which tells you whether or not the table has had records inserted) and call the appropriate DBCC CHECKIDENT command in each case. It is as follows:

DECLARE @last_value INT = CONVERT(INT, (SELECT last_value FROM sys.identity_columns WHERE OBJECT_NAME(OBJECT_ID) = 'MyTable'));
IF @last_value IS NULL
    BEGIN
        -- Table newly created and no rows inserted yet; start the IDs off from 1
        DBCC CHECKIDENT ('MyTable', RESEED, 1);
    END
ELSE
    BEGIN
        -- Table has rows; ensure the IDs continue from the last ID used
        DECLARE @lastValUsed INT = (SELECT ISNULL(MAX(ID),0) FROM MyTable);
        DBCC CHECKIDENT ('MyTable', RESEED, @lastValUsed);
    END

Tools: replace not replacing in Android manifest

You can replace those in your Manifest application tag:

<application
    tools:replace="android:icon, android:label, android:theme, android:name,android:allowBackup"
android:allowBackup="false"...>

and will work for you.

ActiveMQ connection refused

Your application is not able to connect to activemq. Check that your activemq is running and listening on localhost 61616.

You can try using: netstat -a to check if the activemq process has started. Or try check if you can access your actvemq using admin page: localhost:8161/admin/queues.jsp

On mac you will start your activemq using:

$ACTMQ_HOME/bin/activemq start 

Or if your config file (activemq.xml ) if located in another location you can use:

$ACTMQ_HOME/bin/activemq start xbean:file:${location_of_your_config_file}

In your case the executable is under: bin/macosx/activemq so you need to use: $ACTMQ_HOME/bin/macosx/activemq start

How to get the current location latitude and longitude in android

**The activity should implements LocationListener

In onCreate(), write the following code **

  Boolean network = haveNetworkConnection();
    Log.e("network", "---------->" + network);
    if (!network) {
        Toast.makeText(getApplicationContext(), "Network is not available",
                3000).show();

    }

    SupportMapFragment supportMapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.googleMap);
    googleMap = supportMapFragment.getMap();
    googleMap.setMyLocationEnabled(true);


    LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 30000, 0, this);




        if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)
            && !locationManager
                    .isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {



         TextView title = new TextView(context);
         title.setText("Location Services Not Active");
            title.setBackgroundColor(Color.BLACK);
            title.setPadding(10, 15, 15, 10);
            title.setGravity(Gravity.CENTER);
            title.setTextColor(Color.WHITE);
            title.setTextSize(22);


            AlertDialog.Builder builder = new AlertDialog.Builder(this);




        builder.setCustomTitle(title);


        // builder.setTitle("Location Services Not Active");
        builder.setMessage("Please enable Location Services and GPS");

        builder.setPositiveButton("Turn on",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialogInterface,
                            int i) {
                        // Show location settings when the user acknowledges
                        // the alert dialog
                        Intent intent = new Intent(
                                Settings.ACTION_LOCATION_SOURCE_SETTINGS);

                        startActivity(intent);
                        finish();
                    }
                });

        builder.setNegativeButton("Cancel",
                new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        dialog.cancel();
                    }
                });

        builder.show();

    }

    Criteria criteria = new Criteria();
    String bestProvider = locationManager.getBestProvider(criteria, true);
    Location location = locationManager.getLastKnownLocation(bestProvider);

    if (location == null) {
        Toast.makeText(getApplicationContext(), "GPS signal not found",
                3000).show();
    }
    if (location != null) {
        Log.e("locatin", "location--" + location);

        Log.e("latitude at beginning",
                "@@@@@@@@@@@@@@@" + location.getLatitude());
        onLocationChanged(location);
    }

Write a method haveNetworkConnection

private boolean haveNetworkConnection() {
    boolean haveConnectedWifi = false;
    boolean haveConnectedMobile = false;

    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo[] netInfo = cm.getAllNetworkInfo();
    for (NetworkInfo ni : netInfo) {
        if (ni.getTypeName().equalsIgnoreCase("WIFI"))
            if (ni.isConnected())
                haveConnectedWifi = true;
        if (ni.getTypeName().equalsIgnoreCase("MOBILE"))
            if (ni.isConnected())
                haveConnectedMobile = true;
    }
    return haveConnectedWifi || haveConnectedMobile;
}



@Override
public void onLocationChanged(Location location) {


    LatLng latLng = new LatLng(latitude, longitude);
    googleMap.addMarker(new MarkerOptions()
            .position(latLng)
            .title("Current LOC")
            .icon(BitmapDescriptorFactory
                    .defaultMarker(BitmapDescriptorFactory.HUE_RED)));

    googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
    googleMap.animateCamera(CameraUpdateFactory.zoomTo(17));


}

@Override
public void onProviderDisabled(String provider) {
    // TODO Auto-generated method stub
}

@Override
public void onProviderEnabled(String provider) {
    // TODO Auto-generated method stub
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub
}

Subtracting Dates in Oracle - Number or Interval Datatype?

Ok, I don't normally answer my own questions but after a bit of tinkering, I have figured out definitively how Oracle stores the result of a DATE subtraction.

When you subtract 2 dates, the value is not a NUMBER datatype (as the Oracle 11.2 SQL Reference manual would have you believe). The internal datatype number of a DATE subtraction is 14, which is a non-documented internal datatype (NUMBER is internal datatype number 2). However, it is actually stored as 2 separate two's complement signed numbers, with the first 4 bytes used to represent the number of days and the last 4 bytes used to represent the number of seconds.

An example of a DATE subtraction resulting in a positive integer difference:

select date '2009-08-07' - date '2008-08-08' from dual;

Results in:

DATE'2009-08-07'-DATE'2008-08-08'
---------------------------------
                              364

select dump(date '2009-08-07' - date '2008-08-08') from dual;

DUMP(DATE'2009-08-07'-DATE'2008
-------------------------------
Typ=14 Len=8: 108,1,0,0,0,0,0,0

Recall that the result is represented as a 2 seperate two's complement signed 4 byte numbers. Since there are no decimals in this case (364 days and 0 hours exactly), the last 4 bytes are all 0s and can be ignored. For the first 4 bytes, because my CPU has a little-endian architecture, the bytes are reversed and should be read as 1,108 or 0x16c, which is decimal 364.

An example of a DATE subtraction resulting in a negative integer difference:

select date '1000-08-07' - date '2008-08-08' from dual;

Results in:

DATE'1000-08-07'-DATE'2008-08-08'
---------------------------------
                          -368160

select dump(date '1000-08-07' - date '2008-08-08') from dual;

DUMP(DATE'1000-08-07'-DATE'2008-08-0
------------------------------------
Typ=14 Len=8: 224,97,250,255,0,0,0,0

Again, since I am using a little-endian machine, the bytes are reversed and should be read as 255,250,97,224 which corresponds to 11111111 11111010 01100001 11011111. Now since this is in two's complement signed binary numeral encoding, we know that the number is negative because the leftmost binary digit is a 1. To convert this into a decimal number we would have to reverse the 2's complement (subtract 1 then do the one's complement) resulting in: 00000000 00000101 10011110 00100000 which equals -368160 as suspected.

An example of a DATE subtraction resulting in a decimal difference:

select to_date('08/AUG/2004 14:00:00', 'DD/MON/YYYY HH24:MI:SS'
 - to_date('08/AUG/2004 8:00:00', 'DD/MON/YYYY HH24:MI:SS') from dual;

TO_DATE('08/AUG/200414:00:00','DD/MON/YYYYHH24:MI:SS')-TO_DATE('08/AUG/20048:00:
--------------------------------------------------------------------------------
                                                                             .25

The difference between those 2 dates is 0.25 days or 6 hours.

select dump(to_date('08/AUG/2004 14:00:00', 'DD/MON/YYYY HH24:MI:SS')
 - to_date('08/AUG/2004 8:00:00', 'DD/MON/YYYY HH24:MI:SS')) from dual;

DUMP(TO_DATE('08/AUG/200414:00:
-------------------------------
Typ=14 Len=8: 0,0,0,0,96,84,0,0

Now this time, since the difference is 0 days and 6 hours, it is expected that the first 4 bytes are 0. For the last 4 bytes, we can reverse them (because CPU is little-endian) and get 84,96 = 01010100 01100000 base 2 = 21600 in decimal. Converting 21600 seconds to hours gives you 6 hours which is the difference which we expected.

Hope this helps anyone who was wondering how a DATE subtraction is actually stored.


You get the syntax error because the date math does not return a NUMBER, but it returns an INTERVAL:

SQL> SELECT DUMP(SYSDATE - start_date) from test;

DUMP(SYSDATE-START_DATE)
-------------------------------------- 
Typ=14 Len=8: 188,10,0,0,223,65,1,0

You need to convert the number in your example into an INTERVAL first using the NUMTODSINTERVAL Function

For example:

SQL> SELECT (SYSDATE - start_date) DAY(5) TO SECOND from test;

(SYSDATE-START_DATE)DAY(5)TOSECOND
----------------------------------
+02748 22:50:04.000000

SQL> SELECT (SYSDATE - start_date) from test;

(SYSDATE-START_DATE)
--------------------
           2748.9515

SQL> select NUMTODSINTERVAL(2748.9515, 'day') from dual;

NUMTODSINTERVAL(2748.9515,'DAY')
--------------------------------
+000002748 22:50:09.600000000

SQL>

Based on the reverse cast with the NUMTODSINTERVAL() function, it appears some rounding is lost in translation.

List of IP Space used by Facebook

The list from 2020-05-23 is:

31.13.24.0/21
31.13.64.0/18
45.64.40.0/22
66.220.144.0/20
69.63.176.0/20
69.171.224.0/19
74.119.76.0/22
102.132.96.0/20
103.4.96.0/22
129.134.0.0/16
147.75.208.0/20
157.240.0.0/16
173.252.64.0/18
179.60.192.0/22
185.60.216.0/22
185.89.216.0/22
199.201.64.0/22
204.15.20.0/22

The method to fetch this list is already documented on Facebook's Developer site, you can make a whois call to see all IPs assigned to Facebook:

whois -h whois.radb.net -- '-i origin AS32934' | grep ^route

CakePHP 3.0 installation: intl extension missing from system

For those who get Package not found error try sudo apt-get install php7-intl then run composer install in your project directory.

What is the shortcut in IntelliJ IDEA to find method / functions?

Windows : ctrl + F12

MacOS : cmd + F12

Above commands will show the functions/methods in the current class.

Press SHIFT TWO times if you want to search both class and method in the whole project.

Use of alloc init instead of new

For a side note, I personally use [Foo new] if I want something in init to be done without using it's return value anywhere. If you do not use the return of [[Foo alloc] init] anywhere then you will get a warning. More or less, I use [Foo new] for eye candy.

Java HttpRequest JSON & Response Handling

The simplest way is using libraries like google-http-java-client but if you want parse the JSON response by yourself you can do that in a multiple ways, you can use org.json, json-simple, Gson, minimal-json, jackson-mapper-asl (from 1.x)... etc

A set of simple examples:

Using Gson:

import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

public class Gson {

    public static void main(String[] args) {
    }

    public HttpResponse http(String url, String body) {

        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            HttpPost request = new HttpPost(url);
            StringEntity params = new StringEntity(body);
            request.addHeader("content-type", "application/json");
            request.setEntity(params);
            HttpResponse result = httpClient.execute(request);
            String json = EntityUtils.toString(result.getEntity(), "UTF-8");

            com.google.gson.Gson gson = new com.google.gson.Gson();
            Response respuesta = gson.fromJson(json, Response.class);

            System.out.println(respuesta.getExample());
            System.out.println(respuesta.getFr());

        } catch (IOException ex) {
        }
        return null;
    }

    public class Response{

        private String example;
        private String fr;

        public String getExample() {
            return example;
        }
        public void setExample(String example) {
            this.example = example;
        }
        public String getFr() {
            return fr;
        }
        public void setFr(String fr) {
            this.fr = fr;
        }
    }
}

Using json-simple:

import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

public class JsonSimple {

    public static void main(String[] args) {

    }

    public HttpResponse http(String url, String body) {

        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            HttpPost request = new HttpPost(url);
            StringEntity params = new StringEntity(body);
            request.addHeader("content-type", "application/json");
            request.setEntity(params);
            HttpResponse result = httpClient.execute(request);

            String json = EntityUtils.toString(result.getEntity(), "UTF-8");
            try {
                JSONParser parser = new JSONParser();
                Object resultObject = parser.parse(json);

                if (resultObject instanceof JSONArray) {
                    JSONArray array=(JSONArray)resultObject;
                    for (Object object : array) {
                        JSONObject obj =(JSONObject)object;
                        System.out.println(obj.get("example"));
                        System.out.println(obj.get("fr"));
                    }

                }else if (resultObject instanceof JSONObject) {
                    JSONObject obj =(JSONObject)resultObject;
                    System.out.println(obj.get("example"));
                    System.out.println(obj.get("fr"));
                }

            } catch (Exception e) {
                // TODO: handle exception
            }

        } catch (IOException ex) {
        }
        return null;
    }
}

etc...

How to reference a file for variables using Bash?

For preventing naming conflicts, only import the variables that you need:

variableInFile () {
    variable="${1}"
    file="${2}"

    echo $(
        source "${file}";
        eval echo \$\{${variable}\}
    )
}

How to find out what is locking my tables?

For getting straight to "who is blocked/blocking" I combined/abbreviated sp_who and sp_lock into a single query which gives a nice overview of who has what object locked to what level.

--Create Procedure WhoLock
--AS
set nocount on
if object_id('tempdb..#locksummary') is not null Drop table #locksummary
if object_id('tempdb..#lock') is not null Drop table #lock
create table #lock (    spid int,    dbid int,    objId int,    indId int,    Type char(4),    resource nchar(32),    Mode char(8),    status char(6))
Insert into #lock exec sp_lock
if object_id('tempdb..#who') is not null Drop table #who
create table #who (     spid int, ecid int, status char(30),
            loginame char(128), hostname char(128),
            blk char(5), dbname char(128), cmd char(16)
            --
            , request_id INT --Needed for SQL 2008 onwards
            --
         )
Insert into #who exec sp_who
Print '-----------------------------------------'
Print 'Lock Summary for ' + @@servername  + ' (excluding tempdb):'
Print '-----------------------------------------' + Char(10)
Select     left(loginame, 28) as loginame, 
    left(db_name(dbid),128) as DB,
    left(object_name(objID),30) as object,
    max(mode) as [ToLevel],
    Count(*) as [How Many],
    Max(Case When mode= 'X' Then cmd Else null End) as [Xclusive lock for command],
    l.spid, hostname
into #LockSummary
from #lock l join #who w on l.spid= w.spid
where dbID != db_id('tempdb') and l.status='GRANT'
group by dbID, objID, l.spid, hostname, loginame

Select * from #LockSummary order by [ToLevel] Desc, [How Many] Desc, loginame, DB, object

Print '--------'
Print 'Who is blocking:'
Print '--------' + char(10)
SELECT p.spid
,convert(char(12), d.name) db_name
, program_name
, p.loginame
, convert(char(12), hostname) hostname
, cmd
, p.status
, p.blocked
, login_time
, last_batch
, p.spid
FROM      master..sysprocesses p
JOIN      master..sysdatabases d ON p.dbid =  d.dbid
WHERE     EXISTS (  SELECT 1
          FROM      master..sysprocesses p2
          WHERE     p2.blocked = p.spid )

Print '--------'
Print 'Details:'
Print '--------' + char(10)
Select     left(loginame, 30) as loginame,  l.spid,
    left(db_name(dbid),15) as DB,
    left(object_name(objID),40) as object,
    mode ,
    blk,
    l.status
from #lock l join #who w on l.spid= w.spid
where dbID != db_id('tempdb') and blk <>0
Order by mode desc, blk, loginame, dbID, objID, l.status

(For what the lock level abbreviations mean, see e.g. https://technet.microsoft.com/en-us/library/ms175519%28v=sql.105%29.aspx)

Copied from: sp_WhoLock – a T-SQL stored proc combining sp_who and sp_lock...

NB the [Xclusive lock for command] column can be misleading -- it shows the current command for that spid; but the X lock could have been triggered by an earlier command in the transaction.

Git cli: get user info from username

While its true that git commits don't have a specific field called "username", a git repo does have users, and the users do have names. ;) If what you want is the github username, then knittl's answer is right. But since your question asked about git cli and not github, here's how you get a git user's email address using the command line:

To see a list of all users in a git repo using the git cli:

git log --format="%an %ae" | sort | uniq

To search for a specific user by name, e.g., "John":

git log --format="%an %ae" | sort | uniq | grep -i john

Mock functions in Go

Warning: This might inflate executable file size a little bit and cost a little runtime performance. IMO, this would be better if golang has such feature like macro or function decorator.

If you want to mock functions without changing its API, the easiest way is to change the implementation a little bit:

func getPage(url string) string {
  if GetPageMock != nil {
    return GetPageMock()
  }

  // getPage real implementation goes here!
}

func downloader() {
  if GetPageMock != nil {
    return GetPageMock()
  }

  // getPage real implementation goes here!
}

var GetPageMock func(url string) string = nil
var DownloaderMock func() = nil

This way we can actually mock one function out of the others. For more convenient we can provide such mocking boilerplate:

// download.go
func getPage(url string) string {
  if m.GetPageMock != nil {
    return m.GetPageMock()
  }

  // getPage real implementation goes here!
}

func downloader() {
  if m.GetPageMock != nil {
    return m.GetPageMock()
  }

  // getPage real implementation goes here!
}

type MockHandler struct {
  GetPage func(url string) string
  Downloader func()
}

var m *MockHandler = new(MockHandler)

func Mock(handler *MockHandler) {
  m = handler
}

In test file:

// download_test.go
func GetPageMock(url string) string {
  // ...
}

func TestDownloader(t *testing.T) {
  Mock(&MockHandler{
    GetPage: GetPageMock,
  })

  // Test implementation goes here!

  Mock(new(MockHandler)) // Reset mocked functions
}

Sort array of objects by string property value

this sorting funciton can be use for all object sorting,

  • object

  • deepObject

  • numeric array

you can also do assending or desending sort by passing 1,-1 as param

_x000D_
_x000D_
Object.defineProperty(Object.prototype, 'deepVal', {_x000D_
    enumerable: false,_x000D_
    writable: true,_x000D_
    value: function (propertyChain) {_x000D_
        var levels = propertyChain.split('.');_x000D_
        parent = this;_x000D_
        for (var i = 0; i < levels.length; i++) {_x000D_
            if (!parent[levels[i]])_x000D_
                return undefined;_x000D_
            parent = parent[levels[i]];_x000D_
        }_x000D_
        return parent;_x000D_
    }_x000D_
});_x000D_
_x000D_
_x000D_
function dynamicSortAll(property,sortOrders=1) {_x000D_
_x000D_
/**default sorting will be ascending order if you need descending order_x000D_
sording you have to pass -1 as param**/_x000D_
_x000D_
    var sortOrder = sortOrders;_x000D_
   _x000D_
    return function (a,b) {_x000D_
_x000D_
   var result =(property? ((a.deepVal(property) > b.deepVal(property)) ? 1 : (a.deepVal(property) < b.deepVal(property)) ? -1 : 0) :((a > b) ? 1 : (a < b) ? -1 : 0))_x000D_
  _x000D_
        return result * sortOrder;_x000D_
  _x000D_
   _x000D_
    }_x000D_
}_x000D_
_x000D_
deepObj = [_x000D_
    {_x000D_
        a: { a: 1, b: 2, c: 3 },_x000D_
        b: { a: 4, b: 5, c: 6 }_x000D_
    },_x000D_
    { _x000D_
        a: { a: 3, b: 2, c: 1 },_x000D_
        b: { a: 6, b: 5, c: 4 }_x000D_
}];_x000D_
_x000D_
let deepobjResult=deepObj.sort(dynamicSortAll('a.a',1))_x000D_
console.log('deepobjResult :'+ JSON.stringify(deepobjResult))_x000D_
var obj = [ _x000D_
    { first_nom: 'Lazslo', last_nom: 'Jamf'     },_x000D_
    { first_nom: 'Pig',    last_nom: 'Bodine'   },_x000D_
    { first_nom: 'Pirate', last_nom: 'Prentice' }_x000D_
];_x000D_
let objResult=obj.sort(dynamicSortAll('last_nom',1))_x000D_
console.log('objResult :'+ JSON.stringify(objResult))_x000D_
_x000D_
var numericObj=[1,2,3,4,5,6]_x000D_
_x000D_
let numResult=numericObj.sort(dynamicSortAll(null,-1))_x000D_
console.log('numResult :'+ JSON.stringify(numResult))_x000D_
_x000D_
let stringSortResult='helloworld'.split('').sort(dynamicSortAll(null,1))_x000D_
_x000D_
 console.log('stringSortResult:'+ JSON.stringify(stringSortResult))_x000D_
_x000D_
let uniqueStringOrger=[...new Set(stringSortResult)]; _x000D_
 console.log('uniqueStringOrger:'+ JSON.stringify(uniqueStringOrger))
_x000D_
_x000D_
_x000D_

VSCode single to double quote automatic replace

For JSX use:

{"jsxSingleQuote": false}

Storing Images in PostgreSQL

If your images are small, consider storing them as base64 in a plain text field.

The reason is that while base64 has an overhead of 33%, with compression that mostly goes away. (See What is the space overhead of Base64 encoding?) Your database will be bigger, but the packets your webserver sends to the client won't be. In html, you can inline base64 in an <img src=""> tag, which can possibly simplify your app because you won't have to serve up the images as binary in a separate browser fetch. Handling images as text also simplifies things when you have to send/receive json, which doesn't handle binary very well.

Yes, I understand you could store the binary in the database and convert it to/from text on the way in and out of the database, but sometimes ORMs make that a hassle. It can be simpler just to treat it as straight text just like all your other fields.

This is definitely the right way to handle thumbnails.

(OP's images are not small, so this is not really an answer to his question.)

Easiest way to use SVG in Android?

First you need to import svg files by following simple steps.

  1. Right click on drawable
  2. Click new
  3. Select Vector Asset

If image is available in your computer then select local svg file. After that select the image path and an option to change the size of the image is also available at the right side of dialog if you want to . in this way svg image is imported in your project After that for using this image use the same procedure

@drawable/yourimagename

How can I recursively find all files in current and subfolders based on wildcard matching?

find will find all files that match a pattern:

find . -name "*foo"

However, if you want a picture:

tree -P "*foo"

Hope this helps!

What do the icons in Eclipse mean?

In eclipse help documentation, we can all icons information as follows. Common path for all eclipse versions except eclipse version:

enter image description here

https://help.eclipse.org/2019-09/index.jsp?nav=%2F1

Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

If your mysql was previously working and has stopped suddenly just "reboot" the server.

Was facing this issue on my CentOS VPS.->

Was constantly getting

Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock'(2)

Tried all techniques, finally restarting the server fixed the issues ->

shutdown -r now

Hope this helps !!

Java - Get a list of all Classes loaded in the JVM

It's not a programmatic solution but you can run

java -verbose:class ....

and the JVM will dump out what it's loading, and from where.

[Opened /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/sunrsasign.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/jsse.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/jce.jar]
[Opened /usr/java/j2sdk1.4.1/jre/lib/charsets.jar]
[Loaded java.lang.Object from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.io.Serializable from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.lang.Comparable from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.lang.CharSequence from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]
[Loaded java.lang.String from /usr/java/j2sdk1.4.1/jre/lib/rt.jar]

See here for more details.

error TS2339: Property 'x' does not exist on type 'Y'

Starting with TypeScript 2.2 using dot notation to access indexed properties is allowed. You won't get error TS2339 on your example.

See Dotted property for types with string index signatures in TypeScript 2.2 release note.

How to change indentation mode in Atom?

Adding @Manbroski answer here that worked for me:

try Ctrl-Shift-P Editor: Toggle Soft Tabs

How to parse a CSV file in Bash?

From the man page:

-d delim The first character of delim is used to terminate the input line, rather than newline.

You are using -d, which will terminate the input line on the comma. It will not read the rest of the line. That's why $y is empty.

Error occurred during initialization of boot layer FindException: Module not found

I just encountered the same issue after adding the bin folder to .gitignore, not sure if that caused the issue.

I solved it by going to Project/Properties/Build Path and I removed the scr folder and added it again.

Python equivalent for HashMap

You need a dict:

my_dict = {'cheese': 'cake'}

Example code (from the docs):

>>> a = dict(one=1, two=2, three=3)
>>> b = {'one': 1, 'two': 2, 'three': 3}
>>> c = dict(zip(['one', 'two', 'three'], [1, 2, 3]))
>>> d = dict([('two', 2), ('one', 1), ('three', 3)])
>>> e = dict({'three': 3, 'one': 1, 'two': 2})
>>> a == b == c == d == e
True

You can read more about dictionaries here.

YAML Multi-Line Arrays

have you tried this?

-
  name: Jack
  age: 32
-
  name: Claudia
  age: 25

I get this: [{"name"=>"Jack", "age"=>32}, {"name"=>"Claudia", "age"=>25}] (I use the YAML Ruby class).

Sort array by firstname (alphabetically) in Javascript

Basically you can sort arrays with method sort, but if you want to sort objects then you have to pass function to sort method of array, so I will give you an example using your array

user = [{
bio: "<null>",
email: "[email protected]",
firstname: 'Anna',
id: 318,
"last_avatar": "<null>",
"last_message": "<null>",
lastname: 'Nickson',
nickname: 'anny'
},
{
bio: "<null>",
email: "[email protected]",
firstname: 'Senad',
id: 318,
"last_avatar": "<null>",
"last_message": "<null>",
lastname: 'Nickson',
nickname: 'anny'
},
{
bio: "<null>",
email: "[email protected]",
firstname: 'Muhamed',
id: 318,
"last_avatar": "<null>",
"last_message": "<null>",
lastname: 'Nickson',
nickname: 'anny'
}];

var ar = user.sort(function(a, b)
{
  var nA = a.firstname.toLowerCase();
  var nB = b.firstname.toLowerCase();

  if(nA < nB)
    return -1;
  else if(nA > nB)
    return 1;
 return 0;
});

How to access SVG elements with Javascript

In case you use jQuery you need to wait for $(window).load, because the embedded SVG document might not be yet loaded at $(document).ready

$(window).load(function () {

    //alert("Document loaded, including graphics and embedded documents (like SVG)");
    var a = document.getElementById("alphasvg");

    //get the inner DOM of alpha.svg
    var svgDoc = a.contentDocument;

    //get the inner element by id
    var delta = svgDoc.getElementById("delta");
    delta.addEventListener("mousedown", function(){ alert('hello world!')}, false);
});

How to for each the hashmap?

I know I'm a bit late for that one, but I'll share what I did too, in case it helps someone else :

HashMap<String, HashMap> selects = new HashMap<String, HashMap>();

for(Map.Entry<String, HashMap> entry : selects.entrySet()) {
    String key = entry.getKey();
    HashMap value = entry.getValue();

    // do what you have to do here
    // In your case, another loop.
}

The server is not responding (or the local MySQL server's socket is not correctly configured) in wamp server

If you use MAMP, make sure it's started. :)

I just ran into this problem, and after starting MAMP the error went away. Not my finest moment.

How to test Spring Data repositories?

When you really want to write an i-test for a spring data repository you can do it like this:

@RunWith(SpringRunner.class)
@DataJpaTest
@EnableJpaRepositories(basePackageClasses = WebBookingRepository.class)
@EntityScan(basePackageClasses = WebBooking.class)
public class WebBookingRepositoryIntegrationTest {

    @Autowired
    private WebBookingRepository repository;

    @Test
    public void testSaveAndFindAll() {
        WebBooking webBooking = new WebBooking();
        webBooking.setUuid("some uuid");
        webBooking.setItems(Arrays.asList(new WebBookingItem()));
        repository.save(webBooking);

        Iterable<WebBooking> findAll = repository.findAll();

        assertThat(findAll).hasSize(1);
        webBooking.setId(1L);
        assertThat(findAll).containsOnly(webBooking);
    }
}

To follow this example you have to use these dependencies:

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.4.197</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.assertj</groupId>
    <artifactId>assertj-core</artifactId>
    <version>3.9.1</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

How to determine whether a year is a leap year?

An alternative one liner:

((((y % 4) + (int((y - (y % 100)) / y) * ((y % 400) / 100))) - 1) < 0)

This was something that I put together for fun (?) that is also 1:1 compatible with C.

(y % 4) >>>It first checks if the year is a leap year via the typical mod-4 check.

(int((y - (y % 100)) / y) >>>It then accounts for those years divisible by 100. If the year is evenly divisible by 100, this will result in a value of 1, otherwise it will result in a value of 0.

((y % 400) / 100))) >>>Next, the year is divided by 400 (and subsequently 100, to return 1, 2, or 3 if it is not.

These two values

(int(y - (y % 100)) / y)

&

((y % 400) / 100)))

are then multiplied together. If the year is not divisible by 100, this will always equal 0, otherwise if it is divisible by 100, but not by 400, it will result in 1, 2, or 3. If it is divisible by both 100 and 400, it will result in 0.

This value is added to (y % 4), which will only be equal to 0 if the year is a leap year after accounting for the edge-cases.

Finally, 1 is subtracted from this remaining value, resulting in -1 if the year is a leap year, and either 0, 1, or 2 if it is not. This value is compared against 0 with the less-than operator. If the year is a leap year this will result in True (or 1, if used in C), otherwise it will return False (or 0, if used in C).

Please note: this code is horribly inefficient, incredibly unreadable, and a detriment to any code attempting to follow proper practices. This was an exercise of mine to see if I could do so, and nothing more.

Further, be aware that ZeroDivisionErrors are a consequence of the input year equaling 0, and must be accounted for.

For example, a VERY basic timeit comparison of 1000 executions shows that, when compared against an equivalent codeblock utilizing simple if-statements and the modulus operator, this one-liner is roughly 5 times slower than its if-block equivalent.

That being said, I do find it highly entertaining!

How to enable scrolling of content inside a modal?

In Bootstrap.css change the background attribute (position) of Modal from fixed to absolute

How can I represent an infinite number in Python?

No one seems to have mentioned about the negative infinity explicitly, so I think I should add it.

For negative infinity:

-math.inf

For positive infinity (just for the sake of completeness):

math.inf

How to keep environment variables when using sudo

You can also combine the two env_keep statements in Ahmed Aswani's answer into a single statement like this:

Defaults env_keep += "http_proxy https_proxy"

You should also consider specifying env_keep for only a single command like this:

Defaults!/bin/[your_command] env_keep += "http_proxy https_proxy"

Conversion from List<T> to array T[]

To go twice as fast by using multiple processor cores HPCsharp nuget package provides:

list.ToArrayPar();

Git Bash won't run my python files?

Add following line in you .bashrc file

############################
# Environment path setting #
############################
export PATH=/c/Python27:/c/Python27/Scripts:$PATH

How to cherry-pick multiple commits

If you have selective revisions to merge, say A, C, F, J from A,B,C,D,E,F,G,H,I,J commits, simply use below command:

git cherry-pick A C F J

How do I load an url in iframe with Jquery

$("#button").click(function () { 
    $("#frame").attr("src", "http://www.example.com/");
});

HTML:

 <div id="mydiv">
     <iframe id="frame" src="" width="100%" height="300">
     </iframe>
 </div>
 <button id="button">Load</button>

How npm start runs a server on port 8000

We have a react application and our development machines are both mac and pc. The start command doesn't work for PC so here is how we got around it:

"start": "PORT=3001 react-scripts start",
"start-pc": "set PORT=3001&& react-scripts start",

On my mac:

npm start

On my pc:

 npm run start-pc

What is the best way to remove the first element from an array?

The size of arrays in Java cannot be changed. So, technically you cannot remove any elements from the array.

One way to simulate removing an element from the array is to create a new, smaller array, and then copy all of the elements from the original array into the new, smaller array.

String[] yourArray = Arrays.copyOfRange(oldArr, 1, oldArr.length);

However, I would not suggest the above method. You should really be using a List<String>. Lists allow you to add and remove items from any index. That would look similar to the following:

List<String> list = new ArrayList<String>(); // or LinkedList<String>();
list.add("Stuff");
// add lots of stuff
list.remove(0); // removes the first item

Clear Application's Data Programmatically

There's a new API introduced in API 19 (KitKat): ActivityManager.clearApplicationUserData().

I highly recommend using it in new applications:

import android.os.Build.*;
if (VERSION_CODES.KITKAT <= VERSION.SDK_INT) {
    ((ActivityManager)context.getSystemService(ACTIVITY_SERVICE))
            .clearApplicationUserData(); // note: it has a return value!
} else {
    // use old hacky way, which can be removed
    // once minSdkVersion goes above 19 in a few years.
}

If you don't want the hacky way you can also hide the button on the UI, so that functionality is just not available on old phones.

Knowledge of this method is mandatory for anyone using android:manageSpaceActivity.


Whenever I use this, I do so from a manageSpaceActivity which has android:process=":manager". There, I manually kill any other processes of my app. This allows me to let a UI stay running and let the user decide where to go next.

private static void killProcessesAround(Activity activity) throws NameNotFoundException {
    ActivityManager am = (ActivityManager)activity.getSystemService(Context.ACTIVITY_SERVICE);
    String myProcessPrefix = activity.getApplicationInfo().processName;
    String myProcessName = activity.getPackageManager().getActivityInfo(activity.getComponentName(), 0).processName;
    for (ActivityManager.RunningAppProcessInfo proc : am.getRunningAppProcesses()) {
        if (proc.processName.startsWith(myProcessPrefix) && !proc.processName.equals(myProcessName)) {
            android.os.Process.killProcess(proc.pid);
        }
    }
}

ExpressJS - throw er Unhandled error event

An instance is probably still running. This will fix it.

killall node

Update: This command will only work on Linux/Ubuntu & Mac.

What steps are needed to stream RTSP from FFmpeg?

Another streaming command I've had good results with is piping the ffmpeg output to vlc to create a stream. If you don't have these installed, you can add them:

sudo apt install vlc ffmpeg

In the example I use an mpeg transport stream (ts) over http, instead of rtsp. I've tried both, but the http ts stream seems to work glitch-free on my playback devices.

I'm using a video capture HDMI>USB device that sets itself up on the video4linux2 driver as input. Piping through vlc must be CPU-friendly, because my old dual-core Pentium CPU is able to do the real-time encoding with no dropped frames. I've also had audio-sync issues with some of the other methods, where this method always has perfect audio-sync.

You will have to adjust the command for your device or file. If you're using a file as input, you won't need all that v4l2 and alsa stuff. Here's the ffmpeg|vlc command:

ffmpeg -thread_queue_size 1024 -f video4linux2 -input_format mjpeg -i /dev/video0 -r 30 -f alsa -ac 1 -thread_queue_size 1024 -i hw:1,0 -acodec aac -vcodec libx264 -preset ultrafast -crf 18 -s hd720 -vf format=yuv420p -profile:v main -threads 0 -f mpegts -|vlc -I dummy - --sout='#std{access=http,mux=ts,dst=:8554}'

For example, lets say your server PC IP is 192.168.0.10, then the stream can be played by this command:

ffplay http://192.168.0.10:8554
#or
vlc http://192.168.0.10:8554

Is it possible to register a http+domain-based URL Scheme for iPhone apps, like YouTube and Maps?

Check the User-Agent and in case it's Mobile Safari, open a myprotocol:// URL to (attempt) to open the iPhone app and have it open Mobile iTunes to the download of the app in case the attempt fails

This sounds a reasonable approach to me, but I don't think you'll be able to get it to open mobile itunes as a second resort. I think you'll have to pick one or the other - either redirect to your app or to itunes.

i.e. if you redirect to myprotocol://, and the app isn't on the phone, you won't get a second chance to redirect to itunes.

You could perhaps first redirect to an (iphone optimised) landing page and give the user the option to click through to your app, or to itunes to get the app if they don't have it? But, you'll be relying on the user to do the right thing there. (Edit: though you could set a cookie so that is a first-time thing only?)

Check an integer value is Null in c#

There is already a correct answer from Adam, but you have another option to refactor your code:

if (Age.GetValueOrDefault() == 0)
{
    // it's null or 0
}

Delete a row from a table by id

And what about trying not to delete but hide that row?

How to gzip all files in all sub-directories into one compressed file in bash

there are lots of compression methods that work recursively command line and its good to know who the end audience is.

i.e. if it is to be sent to someone running windows then zip would probably be best:

zip -r file.zip folder_to_zip

unzip filenname.zip

for other linux users or your self tar is great

tar -cvzf filename.tar.gz folder

tar -cvjf filename.tar.bz2 folder  # even more compression

#change the -c to -x to above to extract

One must be careful with tar and how things are tarred up/extracted, for example if I run

cd ~
tar -cvzf passwd.tar.gz /etc/passwd
tar: Removing leading `/' from member names
/etc/passwd


pwd

/home/myusername

tar -xvzf passwd.tar.gz

this will create /home/myusername/etc/passwd

unsure if all versions of tar do this:

 Removing leading `/' from member names

Uncaught TypeError: undefined is not a function on loading jquery-min.js

I had this problem recently with the jQuery Validation plug-in, using Squishit, also getting the js error:

"undefined is not a function"

I fixed it by changing the reference to the unminified jquery.validate.js file, rather than jquery.validate.min.js.

@MvcHtmlString.Create(
    @SquishIt.Framework.Bundle.JavaScript()
        .Add("~/Scripts/Libraries/jquery-1.8.2.min.js")
        .Add("~/Scripts/Libraries/jquery-ui-1.9.1.custom.min.js")
        .Add("~/Scripts/Libraries/jquery.unobtrusive-ajax.min.js")
        .Add("~/Scripts/Libraries/jquery.validate.js")
        .Add("~/Scripts/Libraries/jquery.validate.unobtrusive.js")
         ... more files

I think that the minified version of certain files, when further compressed using Squishit, for example, might in some cases not deal with missing semi-colons and the like, as @Dustin suggests, so you might have to experiment with which files you can doubly compress, and which you just leave to Squishit or whatever you're bundling with.

What are ABAP and SAP?

SAP is really a big Company that offers incredible solutions oriented to medium-large companies.

Actually, I can say that the main IT products are: ERP, WEB, Human Resources, Integration, BI, Reports, Machine Learning, Mobile, Cloud, Robotics, and so on.

On the cloud, you can even find solutions using Cloud Foundry, NodeJS, HTML5, Java, etc.

It's really huge the solutions that offers to their customers.

Appending to an existing string

you can also use the following:

s.concat("world")

Ubuntu apt-get unable to fetch packages

I have been fighting the same thing for a while.

after all the research, this is the best solution.....

add the following to your resolve.conf file /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4

https://serverfault.com/questions/717226/ubuntu14-04-unable-to-apt-get-update/771826#771826

How to filter WooCommerce products by custom attribute

Try WooCommerce Product Filter, plugin developed by Mihajlovicnenad.com. You can filter your products by any criteria. Also, it integrates with your Shop and archive pages perfectly. Here is a screenshot. And this is just one of the layouts, you can customize and make your own. Look at demo site. Thanks! enter image description here

Can't change z-index with JQuery

because your jQuery code is wrong. Correctly would be:

var theParent = $(this).parent().get(0); 
$(theParent).css('z-index', 3000);

How can I set the 'backend' in matplotlib in Python?

This can also be set in the configuration file matplotlibrc (as explained in the error message), for instance:

# The default backend; one of GTK GTKAgg GTKCairo GTK3Agg GTK3Cairo
# CocoaAgg MacOSX Qt4Agg Qt5Agg TkAgg WX WXAgg Agg Cairo GDK PS PDF SVG
backend : Agg

That way, the backend does not need to be hardcoded if the code is shared with other people. For more information, check the documentation.

Split a string by another string in C#

The previous answers are all correct. I go one step further and make C# work for me by defining an extension method on String:

public static class Extensions
{
    public static string[] Split(this string toSplit, string splitOn) {
        return toSplit.Split(new string[] { splitOn }, StringSplitOptions.None);
    }
}

That way I can call it on any string in the simple way I naively expected the first time I tried to accomplish this:

"a big long string with stuff to split on".Split("g str");

Python socket connection timeout

For setting the Socket timeout, you need to follow these steps:

import socket
socks = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socks.settimeout(10.0) # settimeout is the attr of socks.

How to start and stop android service from a adb shell?

To stop a service, you have to find service name using:

adb shell dumpsys activity services <your package>

for example: adb shell dumpsys activity services com.xyz.something

This will list services running for your package.
Output should be similar to:

ServiceRecord{xxxxx u0 com.xyz.something.beta/xyz.something.abc.XYZService}

Now select your service and run:

adb shell am stopservice <service_name> 

For example:

adb shell am stopservice com.xyz.something.beta/xyz.something.abc.XYZService

similarly, to start service:

adb shell am startservice <service_name>

To access service, your service(in AndroidManifest.xml) should set exported="true"

<!-- Service declared in manifest -->
<service
    android:name=".YourServiceName"
    android:exported="true"
    android:launchMode="singleTop">
    <intent-filter>
        <action android:name="com.your.package.name.YourServiceName"/>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</service>

How do I shrink my SQL Server Database?

I think you can remove all your log with switch from full to simple recovery. Right click on your Database and select Properties and select Options and change

  • Recovery mode to Simple
  • Containment type to None

Switching from full to simple

nginx - nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)

I use supervisor to run Nginx and Gunicorn side by side on a Docker container.

This was the configuration used for supervisor :

[supervisord]
nodaemon=true

[program:gunicorn]
command = /project/start.sh
user = www-data


[program:nginx]
command=/usr/sbin/nginx

The problem was how I launched Ngnix : by default it runs on the foreground. This makes supervise retry to run another instance of Nginx.

By adding -g 'daemon off;' to the command line, Nginx stayed in the foreground, supervisor stopped trying to run another instance.

Java: notify() vs. notifyAll() all over again

To summarize the excellent detailed explanations above, and in the simplest way I can think of, this is due to the limitations of the JVM built-in monitor, which 1) is acquired on the entire synchronization unit (block or object) and 2) does not discriminate about the specific condition being waited/notified on/about.

This means that if multiple threads are waiting on different conditions and notify() is used, the selected thread may not be the one which would make progress on the newly fulfilled condition - causing that thread (and other currently still waiting threads which would be able to fulfill the condition, etc..) not to be able to make progress, and eventually starvation or program hangup.

In contrast, notifyAll() enables all waiting threads to eventually re-acquire the lock and check for their respective condition, thereby eventually allowing progress to be made.

So notify() can be used safely only if any waiting thread is guaranteed to allow progress to be made should it be selected, which in general is satisfied when all threads within the same monitor check for only one and the same condition - a fairly rare case in real world applications.

Select All as default value for Multivalue parameter

Does not work if you have nulls.

You can get around this by modifying your select statement to plop something into nulls:

phonenumber = CASE
  WHEN (isnull(phonenumber, '')='') THEN '(blank)'
  ELSE phonenumber
END

Python function as a function argument?

  1. Yes, it's allowed.
  2. You use the function as you would any other: anotherfunc(*extraArgs)

Change Default branch in gitlab

Settings > Repository > Default Branch

enter image description here

How to draw a rectangle around a region of interest in python

You can use cv2.rectangle():

cv2.rectangle(img, pt1, pt2, color, thickness, lineType, shift)

Draws a simple, thick, or filled up-right rectangle.

The function rectangle draws a rectangle outline or a filled rectangle
whose two opposite corners are pt1 and pt2.

Parameters
    img   Image.
    pt1   Vertex of the rectangle.
    pt2    Vertex of the rectangle opposite to pt1 .
    color Rectangle color or brightness (grayscale image).
    thickness  Thickness of lines that make up the rectangle. Negative values,
    like CV_FILLED , mean that the function has to draw a filled rectangle.
    lineType  Type of the line. See the line description.
    shift   Number of fractional bits in the point coordinates.

I have a PIL Image object and I want to draw rectangle on this image, but PIL's ImageDraw.rectangle() method does not have the ability to specify line width. I need to convert Image object to opencv2's image format and draw rectangle and convert back to Image object. Here is how I do it:

# im is a PIL Image object
im_arr = np.asarray(im)
# convert rgb array to opencv's bgr format
im_arr_bgr = cv2.cvtColor(im_arr, cv2.COLOR_RGB2BGR)
# pts1 and pts2 are the upper left and bottom right coordinates of the rectangle
cv2.rectangle(im_arr_bgr, pts1, pts2,
              color=(0, 255, 0), thickness=3)
im_arr = cv2.cvtColor(im_arr_bgr, cv2.COLOR_BGR2RGB)
# convert back to Image object
im = Image.fromarray(im_arr)

Best C/C++ Network Library

Aggregated List of Libraries

PHP - Modify current object in foreach loop

There are 2 ways of doing this

foreach($questions as $key => $question){
    $questions[$key]['answers'] = $answers_model->get_answers_by_question_id($question['question_id']);
}

This way you save the key, so you can update it again in the main $questions variable

or

foreach($questions as &$question){

Adding the & will keep the $questions updated. But I would say the first one is recommended even though this is shorter (see comment by Paystey)

Per the PHP foreach documentation:

In order to be able to directly modify array elements within the loop precede $value with &. In that case the value will be assigned by reference.

How to give ASP.NET access to a private key in a certificate in the certificate store?

  1. Create / Purchase certificate. Make sure it has a private key.
  2. Import the certificate into the "Local Computer" account. Best to use Certificates MMC. Make sure to check "Allow private key to be exported"
  3. Based upon which, IIS 7.5 Application Pool's identity use one of the following.

    • IIS 7.5 Website is running under ApplicationPoolIdentity. Open MMC => Add Certificates (Local computer) snap-in => Certificates (Local Computer) => Personal => Certificates => Right click the certificate of interest => All tasks => Manage private key => Add IIS AppPool\AppPoolName and grant it Full control. Replace "AppPoolName" with the name of your application pool (sometimes IIS_IUSRS)
    • IIS 7.5 Website is running under NETWORK SERVICE. Using Certificates MMC, added "NETWORK SERVICE" to Full Trust on certificate in "Local Computer\Personal".
    • IIS 7.5 Website is running under "MyIISUser" local computer user account. Using Certificates MMC, added "MyIISUser" (a new local computer user account) to Full Trust on certificate in "Local Computer\Personal".

Update based upon @Phil Hale comment:

Beware, if you're on a domain, your domain will be selected by default in the 'from location box'. Make sure to change that to "Local Computer". Change the location to "Local Computer" to view the app pool identities.

How can I increment a date by one day in Java?

Construct a Calendar object and use the method add(Calendar.DATE, 1);

Trigger function when date is selected with jQuery UI datepicker

If you are also interested in the case where the user closes the date selection dialog without selecting a date (in my case choosing no date also has meaning) you can bind to the onClose event:

$('#datePickerElement').datepicker({
         onClose: function (dateText, inst) {
            //you will get here once the user is done "choosing" - in the dateText you will have 
            //the new date or "" if no date has been selected             
      });

Fixed digits after decimal with f-strings

When it comes to float numbers, you can use format specifiers:

f'{value:{width}.{precision}}'

where:

  • value is any expression that evaluates to a number
  • width specifies the number of characters used in total to display, but if value needs more space than the width specifies then the additional space is used.
  • precision indicates the number of characters used after the decimal point

What you are missing is the type specifier for your decimal value. In this link, you an find the available presentation types for floating point and decimal.

Here you have some examples, using the f (Fixed point) presentation type:

# notice that it adds spaces to reach the number of characters specified by width
In [1]: f'{1 + 3 * 1.5:10.3f}'
Out[1]: '     5.500'

# notice that it uses more characters than the ones specified in width
In [2]: f'{3000 + 3 ** (1 / 2):2.1f}' 
Out[2]: '3001.7'

In [3]: f'{1.2345 + 4 ** (1 / 2):9.6f}'
Out[3]: ' 3.234500'

# omitting width but providing precision will use the required characters to display the number with the the specified decimal places
In [4]: f'{1.2345 + 3 * 2:.3f}' 
Out[4]: '7.234'

# not specifying the format will display the number with as many digits as Python calculates
In [5]: f'{1.2345 + 3 * 0.5}'
Out[5]: '2.7344999999999997'

How to check if all of the following items are in a list?

Not OP's case, but - for anyone who wants to assert intersection in dicts and ended up here due to poor googling (e.g. me) - you need to work with dict.items:

>>> a = {'key': 'value'}
>>> b = {'key': 'value', 'extra_key': 'extra_value'}
>>> all(item in a.items() for item in b.items())
True
>>> all(item in b.items() for item in a.items())
False

That's because dict.items returns tuples of key/value pairs, and much like any object in Python, they're interchangeably comparable

Cannot delete directory with Directory.Delete(path, true)

I'm surprised that no one thought of this simple non-recursive method, which can delete directories containing read only files, without needing to change read only attribute of each of them.

Process.Start("cmd.exe", "/c " + @"rmdir /s/q C:\Test\TestDirectoryContainingReadOnlyFiles"); 

(Change a bit to not to fire a cmd window momentarily, which is available all over the internet)

Class not registered Error

Long solved I'm sure but this might help some other poor soul.

This error can ocurre if the DLL you are deploying in the install package is not the same as the DLL you are referencing (these will have different IDs)

Sounds obvious but can easily happen if you make a small change to the dll and have previously installed the app on your own machine which reregisters the dll.

Why do many examples use `fig, ax = plt.subplots()` in Matplotlib/pyplot/python

As a supplement to the question and above answers there is also an important difference between plt.subplots() and plt.subplot(), notice the missing 's' at the end.

One can use plt.subplots() to make all their subplots at once and it returns the figure and axes (plural of axis) of the subplots as a tuple. A figure can be understood as a canvas where you paint your sketch.

# create a subplot with 2 rows and 1 columns
fig, ax = plt.subplots(2,1)

Whereas, you can use plt.subplot() if you want to add the subplots separately. It returns only the axis of one subplot.

fig = plt.figure() # create the canvas for plotting
ax1 = plt.subplot(2,1,1) 
# (2,1,1) indicates total number of rows, columns, and figure number respectively
ax2 = plt.subplot(2,1,2)

However, plt.subplots() is preferred because it gives you easier options to directly customize your whole figure

# for example, sharing x-axis, y-axis for all subplots can be specified at once
fig, ax = plt.subplots(2,2, sharex=True, sharey=True)

Shared axes whereas, with plt.subplot(), one will have to specify individually for each axis which can become cumbersome.

ruby 1.9: invalid byte sequence in UTF-8

I've encountered string, which had mixings of English, Russian and some other alphabets, which caused exception. I need only Russian and English, and this currently works for me:

ec1 = Encoding::Converter.new "UTF-8","Windows-1251",:invalid=>:replace,:undef=>:replace,:replace=>""
ec2 = Encoding::Converter.new "Windows-1251","UTF-8",:invalid=>:replace,:undef=>:replace,:replace=>""
t = ec2.convert ec1.convert t

How do I unset an element in an array in javascript?

If you know the key name simply do like this:

delete array['key_name']

Get the value of bootstrap Datetimepicker in JavaScript

I'm using the latest Bootstrap 3 DateTime Picker (http://eonasdan.github.io/bootstrap-datetimepicker/)

This is how you should use DateTime Picker inline:

var selectedDate = $("#datetimepicker").find(".active").data("day");

The above returned: 03/23/2017

In Javascript/jQuery what does (e) mean?

It's a reference to the current event object

Java String new line

To make the code portable to any system, I would use:

public static String newline = System.getProperty("line.separator");

This is important because different OSs use different notations for newline: Windows uses "\r\n", Classic Mac uses "\r", and Mac and Linux both use "\n".

Commentors - please correct me if I'm wrong on this...

Why is “while ( !feof (file) )” always wrong?

feof() is not very intuitive. In my very humble opinion, the FILE's end-of-file state should be set to true if any read operation results in the end of file being reached. Instead, you have to manually check if the end of file has been reached after each read operation. For example, something like this will work if reading from a text file using fgetc():

#include <stdio.h>

int main(int argc, char *argv[])
{
  FILE *in = fopen("testfile.txt", "r");

  while(1) {
    char c = fgetc(in);
    if (feof(in)) break;
    printf("%c", c);
  }

  fclose(in);
  return 0;
}

It would be great if something like this would work instead:

#include <stdio.h>

int main(int argc, char *argv[])
{
  FILE *in = fopen("testfile.txt", "r");

  while(!feof(in)) {
    printf("%c", fgetc(in));
  }

  fclose(in);
  return 0;
}

How to pass arguments and redirect stdin from a file to program run in gdb?

Start GDB on your project.

  1. Go to project directory, where you've already compiled the project executable. Issue the command gdb and the name of the executable as below:

    gdb projectExecutablename

This starts up gdb, prints the following: GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.04) 7.11.1 Copyright (C) 2016 Free Software Foundation, Inc. ................................................. Type "apropos word" to search for commands related to "word"... Reading symbols from projectExecutablename...done. (gdb)

  1. Before you start your program running, you want to set up your breakpoints. The break command allows you to do so. To set a breakpoint at the beginning of the function named main:

    (gdb) b main

  2. Once you've have the (gdb) prompt, the run command starts the executable running. If the program you are debugging requires any command-line arguments, you specify them to the run command. If you wanted to run my program on the "xfiles" file (which is in a folder "mulder" in the project directory), you'd do the following:

    (gdb) r mulder/xfiles

Hope this helps.

Disclaimer: This solution is not mine, it is adapted from https://web.stanford.edu/class/cs107/guide_gdb.html This short guide to gdb was, most probably, developed at Stanford University.

How to convert a negative number to positive?

If "keep a positive one" means you want a positive number to stay positive, but also convert a negative number to positive, use abs():

>>> abs(-1)
1
>>> abs(1)
1

Scale Image to fill ImageView width and keep aspect ratio

FOR IMAGE VIEW (set these parameters)

android:layout_width     = "match_parent"
android:layout_height    = "wrap_content"
android:scaleType        = "fitCenter"
android:adjustViewBounds = "true"

Now whatever the size of the image is there, it's width will match the parent and height will be according to match the ratio. I have tested this and I am 100% sure.

we want this --> adjustViewBound = true

not this --> adjustViewBound = false

// Results will be: 
Image width -> stretched as match parent
Image height -> according to image width (maximum to aspect ratio)

// like the first one

Removing duplicates from a String in Java

Code to remove the duplicate characters in a string without using any additional buffer. NOTE: One or two additional variables are fine. An extra array is not:

import java.util.*;
public class Main{
    public static char[] removeDupes(char[] arr){
        if (arr == null || arr.length < 2)
            return arr;
        int len = arr.length;
        int tail = 1;
        for(int x = 1; x < len; x++){
            int y;
            for(y = 0; y < tail; y++){
                if (arr[x] == arr[y]) break;
            }
            if (y == tail){
                arr[tail] = arr[x];
                tail++;
            }
        }
        return Arrays.copyOfRange(arr, 0, tail);
    }

    public static char[] bigArr(int len){
        char[] arr = new char[len];
        Random r = new Random();
        String alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890!@#$%^&*()-=_+[]{}|;:',.<>/?`~";

        for(int x = 0; x < len; x++){
            arr[x] = alphabet.charAt(r.nextInt(alphabet.length()));
        }

        return arr;
    }
    public static void main(String args[]){

        String result = new String(removeDupes(new char[]{'a', 'b', 'c', 'd', 'a'}));
        assert "abcd".equals(result) : "abcda should return abcd but it returns: " + result;

        result = new String(removeDupes(new char[]{'a', 'a', 'a', 'a'}));
        assert "a".equals(result) : "aaaa should return a but it returns: " + result;

        result = new String(removeDupes(new char[]{'a', 'b', 'c', 'a'}));
        assert "abc".equals(result) : "abca should return abc but it returns: " + result;

        result = new String(removeDupes(new char[]{'a', 'a', 'b', 'b'}));
        assert "ab".equals(result) : "aabb should return ab but it returns: " + result;

        result = new String(removeDupes(new char[]{'a'}));
        assert "a".equals(result) : "a should return a but it returns: " + result;

        result = new String(removeDupes(new char[]{'a', 'b', 'b', 'a'}));
        assert "ab".equals(result) : "abba should return ab but it returns: " + result;


        char[] arr = bigArr(5000000);
        long startTime = System.nanoTime();
        System.out.println("2: " + new String(removeDupes(arr)));
        long endTime = System.nanoTime();
        long duration = (endTime - startTime);
        System.out.println("Program took: " + duration + " nanoseconds");
        System.out.println("Program took: " + duration/1000000000 + " seconds");

    }
}

How to read and talk about the above code:

  1. The method called removeDupes takes an array of primitive char called arr.
  2. arr is returned as an array of primitive characters "by value". The arr passed in is garbage collected at the end of Main's member method removeDupes.
  3. The runtime complexity of this algorithm is O(n) or more specifically O(n+(small constant)) the constant being the unique characters in the entire array of primitive chars.
  4. The copyOfRange does not increase runtime complexity significantly since it only copies a small constant number of items. The char array called arr is not stepped all the way through.
  5. If you pass null into removeDupes, the method returns null.
  6. If you pass an empty array of primitive chars or an array containing one value, that unmodified array is returned.
  7. Method removeDupes goes about as fast as physically possible, fully utilizing the L1 and L2 cache, so Branch redirects are kept to a minimum.
  8. A 2015 standard issue unburdened computer should be able to complete this method with an primitive char array containing 500 million characters between 15 and 25 seconds.

Explain how this code works:

The first part of the array passed in is used as the repository for the unique characters that are ultimately returned. At the beginning of the function the answer is: "the characters between 0 and 1" as between 0 and tail.

We define the variable y outside of the loop because we want to find the first location where the array index that we are looking at has been duplicated in our repository. When a duplicate is found, it breaks out and quits, the y==tail returns false and the repository is not contributed to.

when the index x that we are peeking at is not represented in our repository, then we pull that one and add it to the end of our repository at index tail and increment tail.

At the end, we return the array between the points 0 and tail, which should be smaller or equal to in length to the original array.

Talking points exercise for coder interviews:

Will the program behave differently if you change the y++ to ++y? Why or why not.

Does the array copy at the end represent another 'N' pass through the entire array making runtime complexity O(n*n) instead of O(n) ? Why or why not.

Can you replace the double equals comparing primitive characters with a .equals? Why or why not?

Can this method be changed in order to do the replacements "by reference" instead of as it is now, "by value"? Why or why not?

Can you increase the efficiency of this algorithm by sorting the repository of unique values at the beginning of 'arr'? Under which circumstances would it be more efficient?

React Modifying Textarea Values

I think you want something along the line of:

Parent:

<Editor name={this.state.fileData} />

Editor:

var Editor = React.createClass({
  displayName: 'Editor',
  propTypes: {
    name: React.PropTypes.string.isRequired
  },
  getInitialState: function() { 
    return {
      value: this.props.name
    };
  },
  handleChange: function(event) {
    this.setState({value: event.target.value});
  },
  render: function() {
    return (
      <form id="noter-save-form" method="POST">
        <textarea id="noter-text-area" name="textarea" value={this.state.value} onChange={this.handleChange} />
        <input type="submit" value="Save" />
      </form>
    );
  }
});

This is basically a direct copy of the example provided on https://facebook.github.io/react/docs/forms.html

Update for React 16.8:

import React, { useState } from 'react';

const Editor = (props) => {
    const [value, setValue] = useState(props.name);

    const handleChange = (event) => {
        setValue(event.target.value);
    };

    return (
        <form id="noter-save-form" method="POST">
            <textarea id="noter-text-area" name="textarea" value={value} onChange={handleChange} />
            <input type="submit" value="Save" />
        </form>
    );
}

Editor.propTypes = {
    name: PropTypes.string.isRequired
};

Android: Proper Way to use onBackPressed() with Toast

This is the best way, because if user not back more than two seconds then reset backpressed value.

declare one global variable.

 private boolean backPressToExit = false;

Override onBackPressed Method.

@Override
public void onBackPressed() {

    if (backPressToExit) {
        super.onBackPressed();
        return;
    }
    this.backPressToExit = true;
    Snackbar.make(findViewById(R.id.yourview), getString(R.string.exit_msg), Snackbar.LENGTH_SHORT).show();
    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            backPressToExit = false;
        }
    }, 2000);
}

Jquery resizing image

Modifying Aleksandar's answer to make it as jquery plugin and accepts maxwidth and maxheight as arguments, suggested by Nathan.

$.fn.resize = function(maxWidth,maxHeight) {
return this.each(function() {
    var ratio = 0;
    var width = $(this).width();
    var height = $(this).height();
    if(width > maxWidth){
        ratio = maxWidth / width;
        $(this).css("width", maxWidth);
        $(this).css("height", height * ratio);
        height = height * ratio;
    }
    var width = $(this).width();
    var height = $(this).height();
    if(height > maxHeight){
        ratio = maxHeight / height;
        $(this).css("height", maxHeight);
        $(this).css("width", width * ratio);
        width = width * ratio;
    }
});
};

Used as $('.imgClass').resize(300,50);

How can I center text (horizontally and vertically) inside a div block?

You can try very easy code for this:

  display: flex;
  align-items: center;
  justify-content: center;

_x000D_
_x000D_
.box{_x000D_
  height: 90px;_x000D_
  width: 90px;_x000D_
  background: green;_x000D_
  display: flex;_x000D_
  align-items: center;_x000D_
  justify-content: center;_x000D_
}
_x000D_
<div class="box">_x000D_
  Lorem_x000D_
</div>
_x000D_
_x000D_
_x000D_

Codepen link: http://codepen.io/santoshkhalse/pen/xRmZwr

How to use comparison and ' if not' in python?

There are two ways. In case of doubt, you can always just try it. If it does not work, you can add extra braces to make sure, like that:

if not ((u0 <= u) and (u < u0+step)):

Get LatLng from Zip Code - Google Maps API

Couldn't you just call the following replaceing the {zipcode} with the zip code or city and state http://maps.googleapis.com/maps/api/geocode/json?address={zipcode}

Google Geocoding

Here is a link with a How To Geocode using JavaScript: Geocode walk-thru. If you need the specific lat/lng numbers call geometry.location.lat() or geometry.location.lng() (API for google.maps.LatLng class)

EXAMPLE to get lat/lng:

    var lat = '';
    var lng = '';
    var address = {zipcode} or {city and state};
    geocoder.geocode( { 'address': address}, function(results, status) {
      if (status == google.maps.GeocoderStatus.OK) {
         lat = results[0].geometry.location.lat();
         lng = results[0].geometry.location.lng();
        });
      } else {
        alert("Geocode was not successful for the following reason: " + status);
      }
    });
    alert('Latitude: ' + lat + ' Logitude: ' + lng);

Load different application.yml in SpringBoot Test

One option is to work with profiles. Create a file called application-test.yml, move all properties you need for those tests to that file and then add the @ActiveProfiles annotation to your test class:

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = Application.class)
@WebAppConfiguration
@IntegrationTest
@ActiveProfiles("test") // Like this
public class MyIntTest{
}

Be aware, it will additionally load the application-test.yml, so all properties that are in application.yml are still going to be applied as well. If you don't want that, either use a profile for those as well, or override them in your application-test.yml.

JavaScript for...in vs for

here is something i did.

function foreach(o, f) {
 for(var i = 0; i < o.length; i++) { // simple for loop
  f(o[i], i); // execute a function and make the obj, objIndex available
 }
}

this is how you would use it
this will work on arrays and objects( such as a list of HTML elements )

foreach(o, function(obj, i) { // for each obj in o
  alert(obj); // obj
  alert(i); // obj index
  /*
    say if you were dealing with an html element may be you have a collection of divs
  */
  if(typeof obj == 'object') { 
   obj.style.marginLeft = '20px';
  }
});

I just made this so I'm open to suggestions :)

How to clear the logs properly for a Docker container?

Here is a cross platform solution to clearing docker container logs:

docker run --rm -v /var/lib/docker:/var/lib/docker alpine sh -c "echo '' > $(docker inspect --format='{{.LogPath}}' CONTAINER_NAME)"

Paste this into your terminal and change CONTAINER_NAME to desired container name or id.

DateTime.TryParse issue with dates of yyyy-dd-MM format

From DateTime on msdn:

Type: System.DateTime% When this method returns, contains the DateTime value equivalent to the date and time contained in s, if the conversion succeeded, or MinValue if the conversion failed. The conversion fails if the s parameter is null, is an empty string (""), or does not contain a valid string representation of a date and time. This parameter is passed uninitialized.

Use parseexact with the format string "yyyy-dd-MM hh:mm tt" instead.

Find intersection of two nested lists?

The & operator takes the intersection of two sets.

{1, 2, 3} & {2, 3, 4}
Out[1]: {2, 3}

Python Threading String Arguments

You're trying to create a tuple, but you're just parenthesizing a string :)

Add an extra ',':

dRecieved = connFile.readline()
processThread = threading.Thread(target=processLine, args=(dRecieved,))  # <- note extra ','
processThread.start()

Or use brackets to make a list:

dRecieved = connFile.readline()
processThread = threading.Thread(target=processLine, args=[dRecieved])  # <- 1 element list
processThread.start()

If you notice, from the stack trace: self.__target(*self.__args, **self.__kwargs)

The *self.__args turns your string into a list of characters, passing them to the processLine function. If you pass it a one element list, it will pass that element as the first argument - in your case, the string.

Merge DLL into EXE?

  1. Install ILMerge as the other threads tell you to

  2. Then go to the installation folder, by default C:\Program Files (x86)\Microsoft\ILMerge

  3. Drag your Dll's and Exes to that folder

  4. Shift-Rightclick in that folder and choose open command prompt

  5. Write

    ilmerge myExe.exe Dll1.dll /out:merged.exe
    

    Note that you should write your exe first.

There you got your merged exe. This might not be the best way if your going to do this multiple times, but the simplest one for a one time use, I would recommend putting Ilmerge to your path.

pandas dataframe create new columns and fill with calculated values from same df

You can do this easily manually for each column like this:

df['A_perc'] = df['A']/df['sum']

If you want to do this in one step for all columns, you can use the div method (http://pandas.pydata.org/pandas-docs/stable/basics.html#matching-broadcasting-behavior):

ds.div(ds['sum'], axis=0)

And if you want this in one step added to the same dataframe:

>>> ds.join(ds.div(ds['sum'], axis=0), rsuffix='_perc')
          A         B         C         D       sum    A_perc    B_perc  \
1  0.151722  0.935917  1.033526  0.941962  3.063127  0.049532  0.305543   
2  0.033761  1.087302  1.110695  1.401260  3.633017  0.009293  0.299283   
3  0.761368  0.484268  0.026837  1.276130  2.548603  0.298739  0.190013   

     C_perc    D_perc  sum_perc  
1  0.337409  0.307517         1  
2  0.305722  0.385701         1  
3  0.010530  0.500718         1  

What is the correct way to do a CSS Wrapper?

You don't need a wrapper, just use the body as the wrapper.

CSS:

body {
    margin:0 auto;
    width:200px;
}

HTML:

<body>
    <p>some content</p>
<body>

Making Enter key on an HTML form submit instead of activating button

Given there is only one (or with this solution potentially not even one) submit button, here is jQuery based solution that will work for multiple forms on the same page...

<script type="text/javascript">
    $(document).ready(function () {

        var makeAllFormSubmitOnEnter = function () {
            $('form input, form select').live('keypress', function (e) {
                if (e.which && e.which == 13) {
                    $(this).parents('form').submit();
                    return false;
                } else {
                    return true;
                }
            });
        };

        makeAllFormSubmitOnEnter();
    });
</script>

Specifying maxlength for multiline textbox

Things have changed in HTML5:

ASPX:

<asp:TextBox ID="txtBox" runat="server" maxlength="2000" TextMode="MultiLine"></asp:TextBox>

C#:

if (!IsPostBack)
{
    txtBox.Attributes.Add("maxlength", txtBox.MaxLength.ToString());
}

Rendered HTML:

<textarea name="ctl00$DemoContentPlaceHolder$txtBox" id="txtBox" maxlength="2000"></textarea>

The metadata for Attributes:

Summary: Gets the collection of arbitrary attributes (for rendering only) that do not correspond to properties on the control.

Returns: A System.Web.UI.AttributeCollection of name and value pairs.

What's the key difference between HTML 4 and HTML 5?

HTML 5 invites you give add a lot of semantic value to your code. What's more, there are natives solution to embed multimedia content.

The rest is important, but it's more technical sugar that will save you from doing the same stuff with a client programming language.

How can I kill whatever process is using port 8080 so that I can vagrant up?

This might help

lsof -n -i4TCP:8080 

The PID is the second field in the output.

Or try:

lsof -i -P

How to clear exisiting dropdownlist items when its content changes?

You should clear out your listbbox prior to binding:

 Me.ddl2.Items.Clear()
  ' now set datasource and bind

Graph implementation C++

I prefer using an adjacency list of Indices ( not pointers )

typedef std::vector< Vertex > Vertices;
typedef std::set <int> Neighbours;


struct Vertex {
private:
   int data;
public:
   Neighbours neighbours;

   Vertex( int d ): data(d) {}
   Vertex( ): data(-1) {}

   bool operator<( const Vertex& ref ) const {
      return ( ref.data < data );
   }
   bool operator==( const Vertex& ref ) const {
      return ( ref.data == data );
   }
};

class Graph
{
private :
   Vertices vertices;
}

void Graph::addEdgeIndices ( int index1, int index2 ) {
  vertices[ index1 ].neighbours.insert( index2 );
}


Vertices::iterator Graph::findVertexIndex( int val, bool& res )
{
   std::vector<Vertex>::iterator it;
   Vertex v(val);
   it = std::find( vertices.begin(), vertices.end(), v );
   if (it != vertices.end()){
        res = true;
       return it;
   } else {
       res = false;
       return vertices.end();
   }
}

void Graph::addEdge ( int n1, int n2 ) {

   bool foundNet1 = false, foundNet2 = false;
   Vertices::iterator vit1 = findVertexIndex( n1, foundNet1 );
   int node1Index = -1, node2Index = -1;
   if ( !foundNet1 ) {
      Vertex v1( n1 );
      vertices.push_back( v1 );
      node1Index = vertices.size() - 1;
   } else {
      node1Index = vit1 - vertices.begin();
   }
   Vertices::iterator vit2 = findVertexIndex( n2, foundNet2);
   if ( !foundNet2 ) {
      Vertex v2( n2 );
      vertices.push_back( v2 );
      node2Index = vertices.size() - 1;
   } else {
      node2Index = vit2 - vertices.begin();
   }

   assert( ( node1Index > -1 ) && ( node1Index <  vertices.size()));
   assert( ( node2Index > -1 ) && ( node2Index <  vertices.size()));

   addEdgeIndices( node1Index, node2Index );
}

convert date string to mysql datetime field

SELECT *
FROM table_name
WHERE CONCAT( SUBSTRING(json_date, 11, 4 ) ,  '-', SUBSTRING( json_date, 7, 2 ) ,  '-', SUBSTRING( json_date, 3, 2 ) ) >= NOW();

json_date ["05/11/2011"]

Memory errors and list limits?

There is no memory limit imposed by Python. However, you will get a MemoryError if you run out of RAM. You say you have 20301 elements in the list. This seems too small to cause a memory error for simple data types (e.g. int), but if each element itself is an object that takes up a lot of memory, you may well be running out of memory.

The IndexError however is probably caused because your ListTemp has got only 19767 elements (indexed 0 to 19766), and you are trying to access past the last element.

It is hard to say what you can do to avoid hitting the limit without knowing exactly what it is that you are trying to do. Using numpy might help. It looks like you are storing a huge amount of data. It may be that you don't need to store all of it at every stage. But it is impossible to say without knowing.

Multiple Order By with LINQ

You can use the ThenBy and ThenByDescending extension methods:

foobarList.OrderBy(x => x.Foo).ThenBy( x => x.Bar)

git stash and git pull

When you have changes on your working copy, from command line do:

git stash 

This will stash your changes and clear your status report

git pull

This will pull changes from upstream branch. Make sure it says fast-forward in the report. If it doesn't, you are probably doing an unintended merge

git stash pop

This will apply stashed changes back to working copy and remove the changes from stash unless you have conflicts. In the case of conflict, they will stay in stash so you can start over if needed.

if you need to see what is in your stash

git stash list

How can I check if a string contains a character in C#?

It will be hard to work in C# without knowing how to work with strings and booleans. But anyway:

        String str = "ABC";
        if (str.Contains('A'))
        { 
            //...
        }

        if (str.Contains("AB"))
        { 
            //...
        }

How to change UIButton image in Swift

From your Obc-C code I think you want to set an Image for button so try this way:

let playButton  = UIButton(type: .Custom)
if let image = UIImage(named: "play.png") {
    playButton.setImage(image, forState: .Normal)
}

In Short:

playButton.setImage(UIImage(named: "play.png"), forState: UIControlState.Normal)

For Swift 3:

let playButton  = UIButton(type: .custom)
playButton.setImage(UIImage(named: "play.png"), for: .normal)

Populating spinner directly in the layout xml

I'm not sure about this, but give it a shot.

In your strings.xml define:

<string-array name="array_name">
<item>Array Item One</item>
<item>Array Item Two</item>
<item>Array Item Three</item>
</string-array>

In your layout:

<Spinner 
        android:id="@+id/spinner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:drawSelectorOnTop="true"
        android:entries="@array/array_name"
    />

I've heard this doesn't always work on the designer, but it compiles fine.

How can I determine the direction of a jQuery scroll event?

You can do it without having to keep track of the previous scroll top, as all the other examples require:

$(window).bind('mousewheel', function(event) {
    if (event.originalEvent.wheelDelta >= 0) {
        console.log('Scroll up');
    }
    else {
        console.log('Scroll down');
    }
});

I am not an expert on this so feel free to research it further, but it appears that when you use $(element).scroll, the event being listened for is a 'scroll' event.

But if you specifically listen for a mousewheel event by using bind, the originalEvent attribute of the event parameter to your callback contains different information. Part of that information is wheelDelta. If it's positive, you moved the mousewheel up. If it's negative, you moved the mousewheel down.

My guess is that mousewheel events will fire when the mouse wheel turns, even if the page does not scroll; a case in which 'scroll' events probably are not fired. If you want, you can call event.preventDefault() at the bottom of your callback to prevent the page from scrolling, and so that you can use the mousewheel event for something other than a page scroll, like some type of zoom functionality.

Getting the .Text value from a TextBox

if(sender is TextBox) {
 var text = (sender as TextBox).Text;
}

Sort an Array by keys based on another Array?

This function return a sub and sorted array based in second parameter $keys

function array_sub_sort(array $values, array $keys){
    $keys = array_flip($keys);
    return array_merge(array_intersect_key($keys, $values), array_intersect_key($values, $keys));
}

Example:

$array_complete = [
    'a' => 1,
    'c' => 3,
    'd' => 4,
    'e' => 5,
    'b' => 2
];

$array_sub_sorted = array_sub_sort($array_complete, ['a', 'b', 'c']);//return ['a' => 1, 'b' => 2, 'c' => 3];

Build an iOS app without owning a mac?

You can use Smartface for developing your app with javascript and deploy to stores directly without a Mac. What they say is below.

With the Cloud Build module, Smartface removes all the hassle of application deployment. You don’t need to worry about managing code signing certificates and having a Mac to sign your apps. Smartface Cloud can store all your iOS certificates and Android keystores in one place and signing and building is fully in the cloud. No matter which operating system you use, you can get store-ready (or enterprise distribution) binaries. Smartface frees you from the lock-in to Mac and allows you to use your favorite operating system for development.

https://www.smartface.io/smartface/

How to prune local tracking branches that do not exist on remote anymore

There's a neat NPM package that does it for you (and it should work cross platform).

Install it with: npm install -g git-removed-branches

And then git removed-branches will show you all the stale local branches, and git removed-branches --prune to actually delete them.

More info here.

Android appcompat v7:23

As seen in the revision column of the Android SDK Manager, the latest published version of the Support Library is 22.2.1. You'll have to wait until 23.0.0 is published.

Edit: API 23 is already published. So u can use 23.0.0

Add 10 seconds to a Date

const timeObject = new Date(); 
timeObject = new Date(timeObject.getTime() + 1000 * 10);
console.log(timeObject);

Also please refer: How to add 30 minutes to a JavaScript Date object?

connect to host localhost port 22: Connection refused

For what its worth I got the following error trying to ssh into my local machine, running Ubuntu 16.04 Xenial, from a vm.

 ssh: connect to host 192.168.144.18 port 22: Connection refused

It got immediately fixed with:

sudo apt-get install ssh

Take note, Before fix: 'which sshd' returned nothing and 'which ssh' returned

/usr/bin/ssh

And After the fix: 'which sshd' returned

/usr/sbin/sshd

Setting ANDROID_HOME enviromental variable on Mac OS X

Setup ANDROID_HOME , JAVA_HOME enviromental variable on Mac OS X

Add In .bash_profile file

export JAVA_HOME=$(/usr/libexec/java_home)

export ANDROID_HOME=/Users/$USER/Library/Android/sdk

export PATH=${PATH}:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools

For Test

echo $ANDROID_HOME
echo $JAVA_HOME

Constant pointer vs Pointer to constant

const int* ptr;

is a pointer to constant (content). You are allowed to modify the pointer. e.g. ptr = NULL, ptr++, but modification of the content is not possible.

int * const ptr;

Is a constant pointer. The opposite is possible. You are not allowed to modify the pointer, but you are allowed to modify what it points to e.g. *ptr += 5.

How to identify object types in java

You want instanceof:

if (value instanceof Integer)

This will be true even for subclasses, which is usually what you want, and it is also null-safe. If you really need the exact same class, you could do

if (value.getClass() == Integer.class)

or

if (Integer.class.equals(value.getClass())