Programs & Examples On #Ibm jdk

How to center icon and text in a android button with width set to "fill parent"

android:drawableLeft is always keeping android:paddingLeft as a distance from the left border. When the button is not set to android:width="wrap_content", it will always hang to the left!

With Android 4.0 (API level 14) you can use android:drawableStart attribute to place a drawable at the start of the text. The only backward compatible solution I've come up with is using an ImageSpan to create a Text+Image Spannable:

Button button = (Button) findViewById(R.id.button);
Spannable buttonLabel = new SpannableString(" Button Text");
buttonLabel.setSpan(new ImageSpan(getApplicationContext(), R.drawable.icon,      
    ImageSpan.ALIGN_BOTTOM), 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
button.setText(buttonLabel);

In my case I needed to also adjust the android:gravity attribute of the Button to make it look centered:

<Button
  android:id="@+id/button"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:minHeight="32dp"
  android:minWidth="150dp"
  android:gravity="center_horizontal|top" />

How do I determine the size of my array in C?

The sizeof way is the right way iff you are dealing with arrays not received as parameters. An array sent as a parameter to a function is treated as a pointer, so sizeof will return the pointer's size, instead of the array's.

Thus, inside functions this method does not work. Instead, always pass an additional parameter size_t size indicating the number of elements in the array.

Test:

#include <stdio.h>
#include <stdlib.h>

void printSizeOf(int intArray[]);
void printLength(int intArray[]);

int main(int argc, char* argv[])
{
    int array[] = { 0, 1, 2, 3, 4, 5, 6 };

    printf("sizeof of array: %d\n", (int) sizeof(array));
    printSizeOf(array);

    printf("Length of array: %d\n", (int)( sizeof(array) / sizeof(array[0]) ));
    printLength(array);
}

void printSizeOf(int intArray[])
{
    printf("sizeof of parameter: %d\n", (int) sizeof(intArray));
}

void printLength(int intArray[])
{
    printf("Length of parameter: %d\n", (int)( sizeof(intArray) / sizeof(intArray[0]) ));
}

Output (in a 64-bit Linux OS):

sizeof of array: 28
sizeof of parameter: 8
Length of array: 7
Length of parameter: 2

Output (in a 32-bit windows OS):

sizeof of array: 28
sizeof of parameter: 4
Length of array: 7
Length of parameter: 1

What is the meaning of "$" sign in JavaScript

Basic syntax is: $(selector).action()

A dollar sign to define jQuery A (selector) to "query (or find)" HTML elements A jQuery action() to be performed on the element(s)

How to get PID of process I've just started within java program?

Since Java 9 class Process has new method long pid(), so it is as simple as

ProcessBuilder pb = new ProcessBuilder("cmd", "/c", "path");
try {
    Process p = pb.start();
    long pid = p.pid();      
} catch (IOException ex) {
    // ...
}

Reading a JSP variable from JavaScript

Assuming you are talking about JavaScript in an HTML document.

You can't do this directly since, as far as the JSP is concerned, it is outputting text, and as far as the page is concerned, it is just getting an HTML document.

You have to generate JavaScript code to instantiate the variable, taking care to escape any characters with special meaning in JS. If you just dump the data (as proposed by some other answers) you will find it falling over when the data contains new lines, quote characters and so on.

The simplest way to do this is to use a JSON library (there are a bunch listed at the bottom of http://json.org/ ) and then have the JSP output:

<script type="text/javascript">
    var myObject = <%= the string output by the JSON library %>;
</script>

This will give you an object that you can access like:

myObject.someProperty

in the JS.

Java 8 - Difference between Optional.flatMap and Optional.map

Okay. You only need to use 'flatMap' when you're facing nested Optionals. Here's the example.

public class Person {

    private Optional<Car> optionalCar;

    public Optional<Car> getOptionalCar() {
        return optionalCar;
    }
}

public class Car {

    private Optional<Insurance> optionalInsurance;

    public Optional<Insurance> getOptionalInsurance() {
        return optionalInsurance;
    }
}

public class Insurance {

    private String name;

    public String getName() {
        return name;
    }

}

public class Test {

    // map cannot deal with nested Optionals
    public Optional<String> getCarInsuranceName(Person person) {
        return person.getOptionalCar()
                .map(Car::getOptionalInsurance) // ? leads to a Optional<Optional<Insurance>
                .map(Insurance::getName);       // ?
    }

}

Like Stream, Optional#map will return a value wrapped by a Optional. That's why we get a nested Optional -- Optional<Optional<Insurance>. And at ?, we want to map it as an Insurance instance, that's how the tragedy happened. The root is nested Optionals. If we can get the core value regardless the shells, we'll get it done. That's what flatMap does.

public Optional<String> getCarInsuranceName(Person person) {
    return person.getOptionalCar()
                 .flatMap(Car::getOptionalInsurance)
                 .map(Insurance::getName);
}

In the end, I stronly recommed the Java 8 In Action to you if you'd like to study Java8 Systematicly.

How to delete a remote tag?

As @CubanX suggested, I've split this answer from my original:

Here is a method which is several times faster than xargs and may scale much more with tweaking. It uses the Github API, a personal access token, and leverages the utility parallel.

git tag | sorting_processing_etc | parallel --jobs 2 curl -i -X DELETE \ 
https://api.github.com/repos/My_Account/my_repo/git/refs/tags/{} -H 
\"authorization: token GIT_OAUTH_OR_PERSONAL_KEY_HERE\"  \
-H \"cache-control: no-cache\"`

parallel has many operating modes, but generally parallelizes any command you give it while allowing you to set limits on the number of processes. You can alter the --jobs 2 parameter to allow faster operation, but I had problems with Github's rate limits, which are currently 5000/hr, but also seems to have an undocumented short-term limit as well.


After this, you'll probably want to delete your local tags too. This is much faster so we can go back to using xargs and git tag -d, which is sufficient.

git tag | sorting_processing_etc | xargs -L 1 git tag -d

How do I list all files of a directory?

Since version 3.4 there are builtin iterators for this which are a lot more efficient than os.listdir():

pathlib: New in version 3.4.

>>> import pathlib
>>> [p for p in pathlib.Path('.').iterdir() if p.is_file()]

According to PEP 428, the aim of the pathlib library is to provide a simple hierarchy of classes to handle filesystem paths and the common operations users do over them.

os.scandir(): New in version 3.5.

>>> import os
>>> [entry for entry in os.scandir('.') if entry.is_file()]

Note that os.walk() uses os.scandir() instead of os.listdir() from version 3.5, and its speed got increased by 2-20 times according to PEP 471.

Let me also recommend reading ShadowRanger's comment below.

Best way to remove an event handler in jQuery?

If you want to respond to an event just one time, the following syntax should be really helpful:

 $('.myLink').bind('click', function() {
   //do some things

   $(this).unbind('click', arguments.callee); //unbind *just this handler*
 });

Using arguments.callee, we can ensure that the one specific anonymous-function handler is removed, and thus, have a single time handler for a given event. Hope this helps others.

Cannot GET / Nodejs Error

Much like leonardocsouza, I had the same problem. To clarify a bit, this is what my folder structure looked like when I ran node server.js

node_modules/
app/
  index.html
  server.js

After printing out the __dirname path, I realized that the __dirname path was where my server was running (app/).

So, the answer to your question is this:

If your server.js file is in the same folder as the files you are trying to render, then

app.use( express.static( path.join( application_root, 'site') ) );

should actually be

app.use(express.static(application_root));

The only time you would want to use the original syntax that you had would be if you had a folder tree like so:

app/
  index.html
node_modules
server.js

where index.html is in the app/ directory, whereas server.js is in the root directory (i.e. the same level as the app/ directory).

Side note: Intead of calling the path utility, you can use the syntax application_root + 'site' to join a path.

Overall, your code could look like:

// Module dependencies.
var application_root = __dirname,
express = require( 'express' ), //Web framework
mongoose = require( 'mongoose' ); //MongoDB integration

//Create server
var app = express();

// Configure server
app.configure( function() {

    //Don't change anything here...

    //Where to serve static content
    app.use( express.static( application_root ) );

    //Nothing changes here either...
});

//Start server --- No changes made here
var port = 5000;
app.listen( port, function() {
    console.log( 'Express server listening on port %d in %s mode', port, app.settings.env );
});

window.location.href doesn't redirect

In case anyone was a tired and silly as I was the other night whereupon I came across many threads espousing the different methods to get a javascript redirect, all of which were failing...

You can't use window.location.replace or document.location.href or any of your favourite vanilla javascript methods to redirect a page to itself.

So if you're dynamically adding in the redirect path from the back end, or pulling it from a data tag, make sure you do check at some stage for redirects to the current page. It could be as simple as:

if(window.location.href == linkout)
{
    location.reload();
}
else
{
    window.location.href = linkout;
}

C# generics syntax for multiple type parameter constraints

void foo<TOne, TTwo>() 
   where TOne : BaseOne
   where TTwo : BaseTwo

More info here:
http://msdn.microsoft.com/en-us/library/d5x73970.aspx

How to filter an array of objects based on values in an inner array with jq?

Here is another solution which uses any/2

map(select(any(.Names[]; contains("data"))|not)|.Id)[]

with the sample data and the -r option it produces

cb94e7a42732b598ad18a8f27454a886c1aa8bbba6167646d8f064cd86191e2b
a4b7e6f5752d8dcb906a5901f7ab82e403b9dff4eaaeebea767a04bac4aada19

How different is Objective-C from C++?

Objective-C is a more perfect superset of C. In C and Objective-C implicit casting from void* to a struct pointer is allowed.

Foo* bar = malloc(sizeof(Foo));

C++ will not compile unless the void pointer is explicitly cast:

Foo* bar = (Foo*)malloc(sizeof(Foo));

The relevance of this to every day programming is zero, just a fun trivia fact.

Difference between map and collect in Ruby?

Ruby aliases the method Array#map to Array#collect; they can be used interchangeably. (Ruby Monk)

In other words, same source code :

               static VALUE
rb_ary_collect(VALUE ary)
{
long i;
VALUE collect;

RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
collect = rb_ary_new2(RARRAY_LEN(ary));
for (i = 0; i < RARRAY_LEN(ary); i++) {
    rb_ary_push(collect, rb_yield(RARRAY_AREF(ary, i)));
}
return collect;
}

http://ruby-doc.org/core-2.2.0/Array.html#method-i-map

How to animate GIFs in HTML document?

By default browser always plays animated gifs, and you can't change that behaviour. If gif image does not animate there can be 2 ways to look: something wrong with the browser, something wrong with the image. Then to exclude the first variant just check trusted image in your browser (run snippet below, this gif definitely animated and works in all browsers).

Your code looks OK. Can you check if this snippet is animated for you?
If YES, then something is bad with your gif, if NO something is wrong with your browser.

_x000D_
_x000D_
<img src="http://i.stack.imgur.com/SBv4T.gif" alt="this slowpoke moves"  width=250/>
_x000D_
_x000D_
_x000D_

How to rebase local branch onto remote master

git fetch origin master:master pulls the latest version of master without needing to check it out.

So all you need is:

git fetch origin master:master && git rebase master

`require': no such file to load -- mkmf (LoadError)

I think is a little late but

sudo yum install -y gcc ruby-devel libxml2 libxml2-devel libxslt libxslt-devel

worked for me on fedora.

http://nokogiri.org/tutorials/installing_nokogiri.html

Markdown and image alignment

this work for me

<p align="center">
 <img src="/LogoOfficial.png" width="300" >
</p>

Eclipse can't find / load main class

I had the same problem, this is my solution:

  1. I manually deleted the bin folder of the project
  2. Then I refreshed the project which recompiled the whole project and created a new bin with all .class files

I did it because when I performed Clean(project->clean) my .class files were not getting deleted. the above solution works for me hope its useful to others.

A simple command line to download a remote maven2 artifact to the local repository?

Since version 2.1 of the Maven Dependency Plugin, there is a dependency:get goal for this purpose. To make sure you are using the right version of the plugin, you'll need to use the "fully qualified name":

mvn org.apache.maven.plugins:maven-dependency-plugin:2.1:get \
    -DrepoUrl=http://download.java.net/maven/2/ \
    -Dartifact=robo-guice:robo-guice:0.4-SNAPSHOT

How do I get the base URL with PHP?

I think the $_SERVER superglobal has the information you're looking for. It might be something like this:

echo $_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI']

You can see the relevant PHP documentation here.

Running an Excel macro via Python?

For Python 3.7 or later,(2018-10-10), I have to combine both @Alejandro BR and SMNALLY's answer, coz @Alejandro forget to define wincl.

import os, os.path
import win32com.client
if os.path.exists('C:/Users/jz/Desktop/test.xlsm'):
    excel_macro = win32com.client.DispatchEx("Excel.Application") # DispatchEx is required in the newest versions of Python.
    excel_path = os.path.expanduser('C:/Users/jz/Desktop/test.xlsm')
    workbook = excel_macro.Workbooks.Open(Filename = excel_path, ReadOnly =1)
    excel_macro.Application.Run("test.xlsm!Module1.Macro1") # update Module1 with your module, Macro1 with your macro
    workbook.Save()
    excel_macro.Application.Quit()  
    del excel_macro

How to comment multiple lines with space or indent

One way to do it would be:

  1. Select the text, Press CTRL + K, C to comment (CTRL+E+C )
  2. Move the cursor to the first line after the delimiter // and before the Code text.
  3. Press Alt + Shift and use arrow keys to make selection. (Remember to make line selection(using down, up arrow keys), not the text selection - See Box Selection and Multi line editing)
  4. Once the selection is done, press space bar to enter a single space.

Notice the vertical blue line in the below image( that will appear once the selection is made, then you can insert any number of characters in between them)

enter image description here

I couldn't find a direct way to do that. The interesting thing is that it is mentioned in the C# Coding Conventions (C# Programming Guide) under Commenting Conventions.

Insert one space between the comment delimiter (//) and the comment text

But the default implementation of commenting in visual studio doesn't insert any space

java SSL and cert keystore

First of all, there're two kinds of keystores.

Individual and General

The application will use the one indicated in the startup or the default of the system.

It will be a different folder if JRE or JDK is running, or if you check the personal or the "global" one.

They are encrypted too

In short, the path will be like:

$JAVA_HOME/lib/security/cacerts for the "general one", who has all the CA for the Authorities and is quite important.

Javascript Date Validation ( DD/MM/YYYY) & Age Checking

with leading zero for day and month

var pattern =/^(0[1-9]|1[0-9]|2[0-9]|3[0-1])\/(0[1-9]|1[0-2])\/([0-9]{4})$/;

and with both leading zero/without leading zero for day and month

var pattern =/^(0?[1-9]|1[0-9]|2[0-9]|3[0-1])\/(0?[1-9]|1[0-2])\/([0-9]{4})$/;

How to destroy Fragment?

Give a try to this

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    // TODO Auto-generated method stub

    FragmentManager manager = ((Fragment) object).getFragmentManager();
    FragmentTransaction trans = manager.beginTransaction();
    trans.remove((Fragment) object);
    trans.commit();

    super.destroyItem(container, position, object);
}

How to use Sublime over SSH

I'm on Windows and have used 4 methods: SFTP, WinSCP, Unison and Sublime Text on Linux with X11 forwarding over SSH to Windows (yes you can do this without messy configs and using a free tool).

The fourth way is the best if you can install software on your Linux machine.

The fourth way:

MobaXterm

  1. Install MobaXterm on Windows
  2. SSH to your Linux box from MobaXterm
  3. On your linux box, install Sublime Text 3. Here's how to on Ubuntu
  4. At the command prompt, start sublime with subl
  5. That's it! You now have sublime text running on Linux, but with its window running on your Windows desktop. This is possible because MobaXterm handles the X11 forwarding over SSH for you so you don't have to do anything funky to get it going. There might be a teeny amount of a delay, but your files will never be out of sync, because you're editing them right on the Linux machine.

Note: When invoking subl if it complains for a certain library - ensure you install them to successfully invoke sublimetext from mobaxterm.

If you can't install software on your Linux box, the best is Unison. Why?

  • It's free
  • It's fast
  • It's reliable and doesn't care which editor you use
  • You can create custom ignore lists

SFTP

Setup: Install the SFTP Sublime Text package. This package requires a license.

  1. Create a new folder
  2. Open it as a Sublime Text Project.
  3. In the sidebar, right click on the folder and select Map Remote.
  4. Edit the sftp-config.json file
  5. Right click the folder in step 1 select download.
  6. Work locally.

In the sftp-config, I usually set:

"upload_on_save": true,
"sync_down_on_open": true,

This, in addition to an SSH terminal to the machine gives me a fairly seamless remote editing experience.

WinSCP

  1. Install and run WinSCP
  2. Go to Preferences (Ctrl+Alt+P) and click on Transfer, then on Add. Name the preset.
  3. Set the transfer mode to binary (you don't want line conversions)
  4. Set file modification to "No change"
  5. Click the Edit button next to File Mask and setup your include and exclude files and folders (useful for when you have a .git/.svn folder present or you want to exclude build products from being synchronized).
  6. Click OK
  7. Connect to your remote server and navigate to the folder of interest
  8. Choose an empty folder on your local machine.
  9. Select your newly created Transfer settings preset.
  10. Finally, hit Ctrl+U (Commands > Keep remote directory up to date) and make sure "Synchronize on start" and "Update subdirectories" are checked.

From then on, WinSCP will keep your changes synchronized.

Work in the local folder using SublimeText. Just make sure that Sublime Text is set to guess the line endings from the file that is being edited.

Unison

I have found that if source tree is massive (around a few hundred MB with a deep hierarchy), then the WinSCP method described above might be a bit slow. You can get much better performance using Unison. The down side is that Unison is not automatic (you need to trigger it with a keypress) and requires a server component to be running on your linux machine. The up side is that the transfers are incredibly fast, it is very reliable and ignoring files, folders and extensions are incredibly easy to setup.

HTML - Change\Update page contents without refreshing\reloading the page

You've got the right idea, so here's how to go ahead: the onclick handlers run on the client side, in the browser, so you cannot call a PHP function directly. Instead, you need to add a JavaScript function that (as you mentioned) uses AJAX to call a PHP script and retrieve the data. Using jQuery, you can do something like this:

<script type="text/javascript">
function recp(id) {
  $('#myStyle').load('data.php?id=' + id);
}
</script>

<a href="#" onClick="recp('1')" > One   </a>
<a href="#" onClick="recp('2')" > Two   </a>
<a href="#" onClick="recp('3')" > Three </a>

<div id='myStyle'>
</div>

Then you put your PHP code into a separate file: (I've called it data.php in the above example)

<?php
  require ('myConnect.php');     
  $id = $_GET['id'];
  $results = mysql_query("SELECT para FROM content WHERE  para_ID='$id'");   
  if( mysql_num_rows($results) > 0 )
  {
   $row = mysql_fetch_array( $results );
   echo $row['para'];
  }
?>

What are the best use cases for Akka framework

I've recently implemented the canonical map-reduce example in Akka: Word count. So it's one use case of Akka: better performance. It was more of a experiment of JRuby and Akka's actors than anything else, but it also shows that Akka is not Scala or Java only: it works on all languages on top of JVM.

How can I use LTRIM/RTRIM to search and replace leading/trailing spaces?

I understand this question is for sql server 2012, but if the same scenario for SQL Server 2017 or SQL Azure you can use Trim directly as below:

UPDATE *tablename*
   SET *columnname* = trim(*columnname*);

How do I convert ticks to minutes?

DateTime mydate = new Date(2012,3,2,5,2,0);
int minute = mydate/600000000;

will return minutes of from given date (mydate) to current time.hope this help.cheers

How to play .wav files with java

Shortest form (without having to install random libraries) ?

public static void play(String filename)
{
    try
    {
        Clip clip = AudioSystem.getClip();
        clip.open(AudioSystem.getAudioInputStream(new File(filename)));
        clip.start();
    }
    catch (Exception exc)
    {
        exc.printStackTrace(System.out);
    }
}

The only problem is there is no good way to make this method blocking to close and dispose the data after *.wav finishes. clip.drain() says it's blocking but it's not. The clip isn't running RIGHT AFTER start(). The only working but UGLY way I found is:

// ...
clip.start();
while (!clip.isRunning())
    Thread.sleep(10);
while (clip.isRunning())
    Thread.sleep(10);
clip.close();

"Too many values to unpack" Exception

This happens to me when I'm using Jinja2 for templates. The problem can be solved by running the development server using the runserver_plus command from django_extensions.

It uses the werkzeug debugger which also happens to be a lot better and has a very nice interactive debugging console. It does some ajax magic to launch a python shell at any frame (in the call stack) so you can debug.

IIS7 URL Redirection from root to sub directory

I think, this could be done without IIS URL Rewrite module. <httpRedirect> supports wildcards, so you can configure it this way:

  <system.webServer>
    <httpRedirect enabled="true">
      <add wildcard="/" destination="/menu_1/MainScreen.aspx" />
    </httpRedirect>
  </system.webServer>

Note that you need to have the "HTTP Redirection" feature enabled on IIS - see HTTP Redirects

What's the reason I can't create generic array types in Java?

There surely must be a good way around it (maybe using reflection), because it seems to me that that's exactly what ArrayList.toArray(T[] a) does. I quote:

public <T> T[] toArray(T[] a)

Returns an array containing all of the elements in this list in the correct order; the runtime type of the returned array is that of the specified array. If the list fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this list.

So one way around it would be to use this function i.e. create an ArrayList of the objects you want in the array, then use toArray(T[] a) to create the actual array. It wouldn't be speedy, but you didn't mention your requirements.

So does anyone know how toArray(T[] a) is implemented?

How to delete a file from SD card?

Also you have to give permission if you are using >1.6 SDK

uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"

in AndroidManifest.xml file

What is the best way to get the first letter from a string in Java, returned as a string of length 1?

Performance wise substring(0, 1) is better as found by following:

    String example = "something";
    String firstLetter  = "";

    long l=System.nanoTime();
    firstLetter = String.valueOf(example.charAt(0));
    System.out.println("String.valueOf: "+ (System.nanoTime()-l));

    l=System.nanoTime();
    firstLetter = Character.toString(example.charAt(0));
    System.out.println("Character.toString: "+ (System.nanoTime()-l));

    l=System.nanoTime();
    firstLetter = example.substring(0, 1);
    System.out.println("substring: "+ (System.nanoTime()-l));

Output:

String.valueOf: 38553
Character.toString: 30451
substring: 8660

why windows 7 task scheduler task fails with error 2147942667

This can happen for more than one reason. In my case this happened due to a permissions issue. The user that the task was running as didn't have permission to write to the logs directory so it failed with this error.

Get GMT Time in Java

Odds are good you did the right stuff on the back end in getting the date, but there's nothing to indicate that you didn't take that GMT time and format it according to your machine's current locale.

final Date currentTime = new Date();

final SimpleDateFormat sdf =
        new SimpleDateFormat("EEE, MMM d, yyyy hh:mm:ss a z");

// Give it to me in GMT time.
sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println("GMT time: " + sdf.format(currentTime));

The key is to use your own DateFormat, not the system provided one. That way you can set the DateFormat's timezone to what you wish, instead of it being set to the Locale's timezone.

Check whether user has a Chrome extension installed

I am sure there is a direct way (calling functions on your extension directly, or by using the JS classes for extensions), but an indirect method (until something better comes along):

Have your Chrome extension look for a specific DIV or other element on your page, with a very specific ID.

For example:

<div id="ExtensionCheck_JamesEggersAwesomeExtension"></div>

Do a getElementById and set the innerHTML to the version number of your extension or something. You can then read the contents of that client-side.

Again though, you should use a direct method if there is one available.


EDIT: Direct method found!!

Use the connection methods found here: https://developer.chrome.com/extensions/extension#global-events

Untested, but you should be able to do...

var myPort=chrome.extension.connect('yourextensionid_qwerqweroijwefoijwef', some_object_to_send_on_connect);

LEFT OUTER JOIN in LINQ

This is the general form (as already provided in other answers)

var c =
    from a in alpha
    join b in beta on b.field1 equals a.field1 into b_temp
    from b_value in b_temp.DefaultIfEmpty()
    select new { Alpha = a, Beta = b_value };

However here's an explanation that I hope will clarify what this actually means!

join b in beta on b.field1 equals a.field1 into b_temp

essentially creates a separate result set b_temp that effectively includes null 'rows' for entries on the right hand side (entries in 'b').

Then the next line:

from b_value in b_temp.DefaultIfEmpty()

..iterates over that result set, setting the default null value for the 'row' on the right hand side, and setting the result of the right hand side row join to the value of 'b_value' (i.e. the value that's on the right hand side,if there's a matching record, or 'null' if there isn't).

Now, if the right hand side is the result of a separate LINQ query, it will consist of anonymous types, which can only either be 'something' or 'null'. If it's an enumerable however (e.g. a List - where MyObjectB is a class with 2 fields), then it's possible to be specific about what default 'null' values are used for its properties:

var c =
    from a in alpha
    join b in beta on b.field1 equals a.field1 into b_temp
    from b_value in b_temp.DefaultIfEmpty( new MyObjectB { Field1 = String.Empty, Field2 = (DateTime?) null })
    select new { Alpha = a, Beta_field1 = b_value.Field1, Beta_field2 = b_value.Field2 };

This ensures that 'b' itself isn't null (but its properties can be null, using the default null values that you've specified), and this allows you to check properties of b_value without getting a null reference exception for b_value. Note that for a nullable DateTime, a type of (DateTime?) i.e. 'nullable DateTime' must be specified as the 'Type' of the null in the specification for the 'DefaultIfEmpty' (this will also apply to types that are not 'natively' nullable e.g double, float).

You can perform multiple left outer joins by simply chaining the above syntax.

Display Images Inline via CSS

You have a line break <br> in-between the second and third images in your markup. Get rid of that, and it'll show inline.

Value of type 'T' cannot be converted to

Both lines have the same problem

T newT1 = "some text";
T newT2 = (string)t;

The compiler doesn't know that T is a string and so has no way of knowing how to assign that. But since you checked you can just force it with

T newT1 = "some text" as T;
T newT2 = t; 

you don't need to cast the t since it's already a string, also need to add the constraint

where T : class

gcc: undefined reference to

Are you mixing C and C++? One issue that can occur is that the declarations in the .h file for a .c file need to be surrounded by:

#if defined(__cplusplus)
  extern "C" {                 // Make sure we have C-declarations in C++ programs
#endif

and:

#if defined(__cplusplus)
  }
#endif

Note: if unable / unwilling to modify the .h file(s) in question, you can surround their inclusion with extern "C":

extern "C" {
#include <abc.h>
} //extern

What is the best way to get all the divisors of a number?

Given your factorGenerator function, here is a divisorGen that should work:

def divisorGen(n):
    factors = list(factorGenerator(n))
    nfactors = len(factors)
    f = [0] * nfactors
    while True:
        yield reduce(lambda x, y: x*y, [factors[x][0]**f[x] for x in range(nfactors)], 1)
        i = 0
        while True:
            f[i] += 1
            if f[i] <= factors[i][1]:
                break
            f[i] = 0
            i += 1
            if i >= nfactors:
                return

The overall efficiency of this algorithm will depend entirely on the efficiency of the factorGenerator.

Convert data file to blob

As pointed in the comments, file is a blob:

file instanceof Blob; // true

And you can get its content with the file reader API https://developer.mozilla.org/en/docs/Web/API/FileReader

Read more: https://developer.mozilla.org/en-US/docs/Using_files_from_web_applications

_x000D_
_x000D_
var input = document.querySelector('input[type=file]');
var textarea = document.querySelector('textarea');

function readFile(event) {
  textarea.textContent = event.target.result;
  console.log(event.target.result);
}

function changeFile() {
  var file = input.files[0];
  var reader = new FileReader();
  reader.addEventListener('load', readFile);
  reader.readAsText(file);
}

input.addEventListener('change', changeFile);
_x000D_
<input type="file">
<textarea rows="10" cols="50"></textarea>
_x000D_
_x000D_
_x000D_

Getting a list item by index

Visual Basic, C#, and C++ all have syntax for accessing the Item property without using its name. Instead, the variable containing the List is used as if it were an array.

List[index]

See for instance: https://msdn.microsoft.com/en-us/library/0ebtbkkc(v=vs.110).aspx

How to send a POST request using volley with string body?

I liked this one, but it is sending JSON not string as requested in the question, reposting the code here, in case the original github got removed or changed, and this one found to be useful by someone.

public static void postNewComment(Context context,final UserAccount userAccount,final String comment,final int blogId,final int postId){
    mPostCommentResponse.requestStarted();
    RequestQueue queue = Volley.newRequestQueue(context);
    StringRequest sr = new StringRequest(Request.Method.POST,"http://api.someservice.com/post/comment", new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            mPostCommentResponse.requestCompleted();
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            mPostCommentResponse.requestEndedWithError(error);
        }
    }){
        @Override
        protected Map<String,String> getParams(){
            Map<String,String> params = new HashMap<String, String>();
            params.put("user",userAccount.getUsername());
            params.put("pass",userAccount.getPassword());
            params.put("comment", Uri.encode(comment));
            params.put("comment_post_ID",String.valueOf(postId));
            params.put("blogId",String.valueOf(blogId));

            return params;
        }

        @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            Map<String,String> params = new HashMap<String, String>();
            params.put("Content-Type","application/x-www-form-urlencoded");
            return params;
        }
    };
    queue.add(sr);
}

public interface PostCommentResponseListener {
    public void requestStarted();
    public void requestCompleted();
    public void requestEndedWithError(VolleyError error);
}

Compare every item to every other item in ArrayList

The following code will compare each item with other list of items using contains() method.Length of for loop must be bigger size() of bigger list then only it will compare all the values of both list.

List<String> str = new ArrayList<String>();
str.add("first");
str.add("second");
str.add("third");
List<String> str1 = new ArrayList<String>();
str1.add("first");
str1.add("second");
str1.add("third1");
for (int i = 0; i<str1.size(); i++)
{
System.out.println(str.contains(str1.get(i)));
}

Output is true true false

Accessing SQL Database in Excel-VBA

I've added the Initial Catalog to your connection string. I've also abandonded the ADODB.Command syntax in favor of simply creating my own SQL statement and open the recordset on that variable.

Hope this helps.

Sub GetDataFromADO()
    'Declare variables'
        Set objMyConn = New ADODB.Connection
        Set objMyRecordset = New ADODB.Recordset
        Dim strSQL As String

    'Open Connection'
        objMyConn.ConnectionString = "Provider=SQLOLEDB;Data Source=localhost;Initial Catalog=MyDatabase;User ID=abc;Password=abc;"
        objMyConn.Open

    'Set and Excecute SQL Command'
        strSQL = "select * from myTable"

    'Open Recordset'
        Set objMyRecordset.ActiveConnection = objMyConn
        objMyRecordset.Open strSQL            

    'Copy Data to Excel'
        ActiveSheet.Range("A1").CopyFromRecordset (objMyRecordset)

End Sub

How to set the context path of a web application in Tomcat 7.0

It's not recommended to update the server configuration like server.xml or ROOT.xml.

You can put a context.xml configuration file under your web-application META-INF directory, with the context path setting included. This will override the default server setting?

i.e.:

<Context docBase="yourAppName" path="/yourAppPath" reloadable="true">

React-Native Button style not work

Try This one

<TouchableOpacity onPress={() => this._onPressAppoimentButton()} style={styles.Btn}>
    <Button title="Order Online" style={styles.Btn} > </Button>
</TouchableOpacity>

How to change Screen buffer size in Windows Command Prompt from batch script

There's a solution at CMD: Set buffer height independently of window height effectively employing a powershell command executed from the batch script. This solution let me resize the scrollback buffer in the existing batch script window independently of the window size, exactly what the OP was asking for.

Caveat: It seems to make the script forget variables (or at least it did with my script), so I recommend calling the command only at the beginning and / or end of your script, or otherwise where you don't depend on a session local variable.

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

Instead of

return new ResponseEntity<JSONObject>(entities, HttpStatus.OK);

try

return new ResponseEntity<List<JSONObject>>(entities, HttpStatus.OK);

What's the difference between git reset --mixed, --soft, and --hard?

mkarasek's Answer is great, in simple terms we can say...

  • git reset --soft : set the HEAD to the intended commit but keep your changes staged from last commits
  • git reset --mixed : it's same as git reset --soft but the only difference is it un stage your changes from last commits
  • git reset --hard : set your HEAD on the commit you specify and reset all your changes from last commits including un committed changes.

Best Practices for securing a REST API / web service

I've used OAuth a few times, and also used some other methods (BASIC/DIGEST). I wholeheartedly suggest OAuth. The following link is the best tutorial I've seen on using OAuth:

http://hueniverse.com/oauth/guide/

Reset the Value of a Select Box

I presume you only want to reset a single element. Resetting an entire form is simple: call its reset method.

The easiest way to "reset" a select element is to set its selectedIndex property to the default value. If you know that no option is the default selected option, just set the select elemen'ts selectedIndex property to an appropriate value:

function resetSelectElement(selectElement) {
    selecElement.selectedIndex = 0;  // first option is selected, or
                                     // -1 for no option selected
}

However, since one option may have the selected attribtue or otherwise be set to the default selected option, you may need to do:

function resetSelectElement(selectElement) {
    var options = selectElement.options;

    // Look for a default selected option
    for (var i=0, iLen=options.length; i<iLen; i++) {

        if (options[i].defaultSelected) {
            selectElement.selectedIndex = i;
            return;
        }
    }

    // If no option is the default, select first or none as appropriate
    selectElement.selectedIndex = 0; // or -1 for no option selected
}

And beware of setting attributes rather than properties, they have different effects in different browsers.

How to format numbers by prepending 0 to single-digit numbers?

Updated for ES6 Arrow Functions (Supported in almost all modern browsers, see CanIUse)

const formatNumber = n => ("0" + n).slice(-2);

Android java.lang.NoClassDefFoundError

Did you recently updated your eclipse android plugin (adt r17)? Then the following link might help:

How to fix the classdefnotfounderror with adt-17

Update: One year has passed since the question arose. I will keep the link, because even in 2013 it seem to help some people to solve the problem. But please take care what you are doing, see Erics comment below. Current ADT-Version is 22, I recommend using the most current version.

How to get number of rows inserted by a transaction

In case you need further info for your log/audit you can OUTPUT clause: This way, not only you keep the number of rows affected, but also what records.

As an example of the Output Clause during inserts: SQL Server list of insert identities

DECLARE @InsertedIDs table(ID int);

INSERT INTO YourTable
    OUTPUT INSERTED.ID
        INTO @InsertedIDs 
    SELECT ...

HTH

Remove by _id in MongoDB console

If you would like to remove by a list of IDs this works great.

db.CollectionName.remove({
    "_id": {
        $in: [
            ObjectId("0930292929292929292929"),
            ObjectId("0920292929292929292929")
        ]
     }
}) 

How to get WooCommerce order details

WOOCOMMERCE ORDERS IN VERSION 3.0+

Since Woocommerce mega major Update 3.0+ things have changed quite a lot:

Related:
How to get Customer details from Order in WooCommerce?
Get Order items and WC_Order_Item_Product in WooCommerce 3

So the Order items properties will not be accessible as before in a foreach loop and you will have to use these specific getter and setter methods instead.

Using some WC_Order and WC_Abstract_Order methods (example):

// Get an instance of the WC_Order object (same as before)
$order = wc_get_order( $order_id );

$order_id  = $order->get_id(); // Get the order ID
$parent_id = $order->get_parent_id(); // Get the parent order ID (for subscriptions…)

$user_id   = $order->get_user_id(); // Get the costumer ID
$user      = $order->get_user(); // Get the WP_User object

$order_status  = $order->get_status(); // Get the order status (see the conditional method has_status() below)
$currency      = $order->get_currency(); // Get the currency used  
$payment_method = $order->get_payment_method(); // Get the payment method ID
$payment_title = $order->get_payment_method_title(); // Get the payment method title
$date_created  = $order->get_date_created(); // Get date created (WC_DateTime object)
$date_modified = $order->get_date_modified(); // Get date modified (WC_DateTime object)

$billing_country = $order->get_billing_country(); // Customer billing country

// ... and so on ...

For order status as a conditional method (where "the_targeted_status" need to be defined and replaced by an order status to target a specific order status):

if ( $order->has_status('completed') ) {
    // Do something
}

Get and access to the order data properties (in an array of values):

// Get an instance of the WC_Order object
$order = wc_get_order( $order_id );

$order_data = $order->get_data(); // The Order data

$order_id = $order_data['id'];
$order_parent_id = $order_data['parent_id'];
$order_status = $order_data['status'];
$order_currency = $order_data['currency'];
$order_version = $order_data['version'];
$order_payment_method = $order_data['payment_method'];
$order_payment_method_title = $order_data['payment_method_title'];
$order_payment_method = $order_data['payment_method'];
$order_payment_method = $order_data['payment_method'];

## Creation and modified WC_DateTime Object date string ##

// Using a formated date ( with php date() function as method)
$order_date_created = $order_data['date_created']->date('Y-m-d H:i:s');
$order_date_modified = $order_data['date_modified']->date('Y-m-d H:i:s');

// Using a timestamp ( with php getTimestamp() function as method)
$order_timestamp_created = $order_data['date_created']->getTimestamp();
$order_timestamp_modified = $order_data['date_modified']->getTimestamp();

$order_discount_total = $order_data['discount_total'];
$order_discount_tax = $order_data['discount_tax'];
$order_shipping_total = $order_data['shipping_total'];
$order_shipping_tax = $order_data['shipping_tax'];
$order_total = $order_data['total'];
$order_total_tax = $order_data['total_tax'];
$order_customer_id = $order_data['customer_id']; // ... and so on

## BILLING INFORMATION:

$order_billing_first_name = $order_data['billing']['first_name'];
$order_billing_last_name = $order_data['billing']['last_name'];
$order_billing_company = $order_data['billing']['company'];
$order_billing_address_1 = $order_data['billing']['address_1'];
$order_billing_address_2 = $order_data['billing']['address_2'];
$order_billing_city = $order_data['billing']['city'];
$order_billing_state = $order_data['billing']['state'];
$order_billing_postcode = $order_data['billing']['postcode'];
$order_billing_country = $order_data['billing']['country'];
$order_billing_email = $order_data['billing']['email'];
$order_billing_phone = $order_data['billing']['phone'];

## SHIPPING INFORMATION:

$order_shipping_first_name = $order_data['shipping']['first_name'];
$order_shipping_last_name = $order_data['shipping']['last_name'];
$order_shipping_company = $order_data['shipping']['company'];
$order_shipping_address_1 = $order_data['shipping']['address_1'];
$order_shipping_address_2 = $order_data['shipping']['address_2'];
$order_shipping_city = $order_data['shipping']['city'];
$order_shipping_state = $order_data['shipping']['state'];
$order_shipping_postcode = $order_data['shipping']['postcode'];
$order_shipping_country = $order_data['shipping']['country'];

Get the order items and access the data with WC_Order_Item_Product and WC_Order_Item methods:

// Get an instance of the WC_Order object
$order = wc_get_order($order_id);

// Iterating through each WC_Order_Item_Product objects
foreach ($order->get_items() as $item_key => $item ):

    ## Using WC_Order_Item methods ##

    // Item ID is directly accessible from the $item_key in the foreach loop or
    $item_id = $item->get_id();

    ## Using WC_Order_Item_Product methods ##

    $product      = $item->get_product(); // Get the WC_Product object

    $product_id   = $item->get_product_id(); // the Product id
    $variation_id = $item->get_variation_id(); // the Variation id

    $item_type    = $item->get_type(); // Type of the order item ("line_item")

    $item_name    = $item->get_name(); // Name of the product
    $quantity     = $item->get_quantity();  
    $tax_class    = $item->get_tax_class();
    $line_subtotal     = $item->get_subtotal(); // Line subtotal (non discounted)
    $line_subtotal_tax = $item->get_subtotal_tax(); // Line subtotal tax (non discounted)
    $line_total        = $item->get_total(); // Line total (discounted)
    $line_total_tax    = $item->get_total_tax(); // Line total tax (discounted)

    ## Access Order Items data properties (in an array of values) ##
    $item_data    = $item->get_data();

    $product_name = $item_data['name'];
    $product_id   = $item_data['product_id'];
    $variation_id = $item_data['variation_id'];
    $quantity     = $item_data['quantity'];
    $tax_class    = $item_data['tax_class'];
    $line_subtotal     = $item_data['subtotal'];
    $line_subtotal_tax = $item_data['subtotal_tax'];
    $line_total        = $item_data['total'];
    $line_total_tax    = $item_data['total_tax'];

    // Get data from The WC_product object using methods (examples)
    $product        = $item->get_product(); // Get the WC_Product object

    $product_type   = $product->get_type();
    $product_sku    = $product->get_sku();
    $product_price  = $product->get_price();
    $stock_quantity = $product->get_stock_quantity();

endforeach;

So using get_data() method allow us to access to the protected data (associative array mode) …

Throwing exceptions from constructors

The only time you would NOT throw exceptions from constructors is if your project has a rule against using exceptions (for instance, Google doesn't like exceptions). In that case, you wouldn't want to use exceptions in your constructor any more than anywhere else, and you'd have to have an init method of some sort instead.

Combining paste() and expression() functions in plot labels

Use substitute instead.

labNames <- c('xLab','yLab')
plot(c(1:10),
     xlab=substitute(paste(nn, x^2), list(nn=labNames[1])),
     ylab=substitute(paste(nn, y^2), list(nn=labNames[2])))

how to sort order of LEFT JOIN in SQL query?

Several other answer give the solution using MAX. In some scenarios using an agregate function is either not possilbe, or not performant.

The alternative that I use a lot is to use a correlated sub-query in the join...

SELECT
   `userName`,
   `carPrice`
FROM `users`
LEFT JOIN `cars`
ON cars.id = (
  SELECT id FROM `cars` WHERE BelongsToUser = users.id ORDER BY carPrice DESC LIMIT 1
)
WHERE `id`='4'

Simple way to understand Encapsulation and Abstraction

data abstraction: accessing data members and member functions of any class is simply called data abstraction.....

encapsulation: binding variables and functions or 1 can say data members or member functions all together in a single unit is called as data encapsulation....

Java decimal formatting using String.format?

NumberFormat and DecimalFormat are definitely what you want. Also, note the NumberFormat.setRoundingMode() method. You can use it to control how rounding or truncation is applied during formatting.

How do I create dynamic variable names inside a loop?

I agree it is generally preferable to use an Array for this.

However, this can also be accomplished in JavaScript by simply adding properties to the current scope (the global scope, if top-level code; the function scope, if within a function) by simply using this – which always refers to the current scope.

for (var i = 0; i < coords.length; ++i) {
    this["marker"+i] = "some stuff";
}

You can later retrieve the stored values (if you are within the same scope as when they were set):

var foo = this.marker0;
console.log(foo); // "some stuff"

This slightly odd feature of JavaScript is rarely used (with good reason), but in certain situations it can be useful.

SQL GROUP BY CASE statement with aggregate function

If you are grouping by some other value, then instead of what you have,

write it as

Sum(CASE WHEN col1 > col2 THEN SUM(col3*col4) ELSE 0 END) as SumSomeProduct

If, otoh, you want to group By the internal expression, (col3*col4) then

write the group By to match the expression w/o the SUM...

Select Sum(Case When col1 > col2 Then col3*col4 Else 0 End) as SumSomeProduct
From ...

Group By Case When col1 > col2 Then col3*col4 Else 0 End 

Finally, if you want to group By the actual aggregate

Select SumSomeProduct, Count(*), <other aggregate functions>
From (Select <other columns you are grouping By>, 
      Sum(Case When col1 > col2 
          Then col3*col4 Else 0 End) as SumSomeProduct
      From Table
      Group By <Other Columns> ) As Z
Group by SumSomeProduct

TypeError: 'str' does not support the buffer interface

For Python 3.x you can convert your text to raw bytes through:

bytes("my data", "encoding")

For example:

bytes("attack at dawn", "utf-8")

The object returned will work with outfile.write.

Convert generator object to list for debugging

Simply call list on the generator.

lst = list(gen)
lst

Be aware that this affects the generator which will not return any further items.

You also cannot directly call list in IPython, as it conflicts with a command for listing lines of code.

Tested on this file:

def gen():
    yield 1
    yield 2
    yield 3
    yield 4
    yield 5
import ipdb
ipdb.set_trace()

g1 = gen()

text = "aha" + "bebe"

mylst = range(10, 20)

which when run:

$ python code.py 
> /home/javl/sandbox/so/debug/code.py(10)<module>()
      9 
---> 10 g1 = gen()
     11 

ipdb> n
> /home/javl/sandbox/so/debug/code.py(12)<module>()
     11 
---> 12 text = "aha" + "bebe"
     13 

ipdb> lst = list(g1)
ipdb> lst
[1, 2, 3, 4, 5]
ipdb> q
Exiting Debugger.

General method for escaping function/variable/debugger name conflicts

There are debugger commands p and pp that will print and prettyprint any expression following them.

So you could use it as follows:

$ python code.py 
> /home/javl/sandbox/so/debug/code.py(10)<module>()
      9 
---> 10 g1 = gen()
     11 

ipdb> n
> /home/javl/sandbox/so/debug/code.py(12)<module>()
     11 
---> 12 text = "aha" + "bebe"
     13 

ipdb> p list(g1)
[1, 2, 3, 4, 5]
ipdb> c

There is also an exec command, called by prefixing your expression with !, which forces debugger to take your expression as Python one.

ipdb> !list(g1)
[]

For more details see help p, help pp and help exec when in debugger.

ipdb> help exec
(!) statement
Execute the (one-line) statement in the context of
the current stack frame.
The exclamation point can be omitted unless the first word
of the statement resembles a debugger command.
To assign to a global variable you must always prefix the
command with a 'global' command, e.g.:
(Pdb) global list_options; list_options = ['-l']

Entity Framework - "An error occurred while updating the entries. See the inner exception for details"

I was facing the same problem and non of the above solutions helped me. In my Web Api 2 project, I had actually updated my database and had placed a unique constraint on an SQL table column. That was actually causing the problem. Simply Checking the the duplicate column values before inserting helped me fix the problem!

How do I install and use curl on Windows?

Thought I'd write exactly what I did (Windows 10, 64-bit):

From the download page https://curl.haxx.se/download.html choose the download wizard https://curl.haxx.se/dlwiz/

Choose curl executable.

Choose Win64.

Choose generic.

Choose any.

Choose x86_64.

Choose the first recommended option. For me this was:

curl version: 7.53.1 - SSL enabled SSH enabled. Provided by: Viktor Szakáts. This package is type curl executable You will get a pre-built 'curl' binary from this link (or in some cases, by using the information that is provided at the page this link takes you). You may or may not get 'libcurl' installed as a shared library/DLL. The file is packaged using 7zip. 7zip is a file archiving format.

Click download.

You should have the file curl-7.53.1-win64-mingw.7z in your downloads folder.

Install 7-Zip if you don't have it.

Right-click, 7-Zip, Extract Here. Copy and paste the extracted file somewhere like Z:\Tools\

If you look in the bin folder you'll see curl.exe. If you double-click it a window will quickly flash up and vanish. To run it you need to use the Command Prompt. Navigate to the bin folder and type curl followed by your parameters to make a request. You must use double-quotes. Single quotes won't work with curl on Windows.

Now you'll want to add curl to a user's Path variable so you don't have to navigate to the right folder to run the program. Go to This PC, Computer, System Properties, Advanced system settings, authenticate as an administrator (you're not running as admin, right? Right?) Environment Variables, System variables, look at the list and select Path, then Edit, then New, then, e.g.

Z:\Tools\curl-7.53.1-win64-mingw\bin

You can add a trailing backslash if you like, I don't think it matters. Click move up until it's at the top of the list, then you can see it easily from the previous screen. Click OK, OK, OK, then crack open a Command Prompt and you can run curl by typing curl from any folder, as any user. Don't forget your double-quotes.

This is the answer I wish I'd had.

No connection could be made because the target machine actively refused it (PHP / WAMP)

You might need:

  • In wamp\bin\mysql\mysqlX.X.XX\my.ini find these lines:

    [client] ... port = 3308 ... [wampmysqld64] ... port = 3308

As you see, the port number is 3308. You should :

  • use that port in applications, like WordPress: define('DB_HOST', 'localhost:3308')

or

  • change it globally in wamp\bin\apache\apache2.X.XXX\bin\php.ini change mysqli.default_port = ... to 3308

How to format a number 0..9 to display with 2 digits (it's NOT a date)

I know that is late to respond, but there are a basic way to do it, with no libraries. If your number is less than 100, then:

(number/100).toFixed(2).toString().slice(2);

How do I detect what .NET Framework versions and service packs are installed?

There is a GUI tool available, ASoft .NET Version Detector, which has always proven highly reliable. It can create XML files by specifying the file name of the XML output on the command line.

You could use this for automation. It is a tiny program, written in a non-.NET dependent language and does not require installation.

How do I finish the merge after resolving my merge conflicts?

It may be late. It is Happen because your git HEAD is not updated. this commend would solve that git reset HEAD.

Docker: "no matching manifest for windows/amd64 in the manifest list entries"

I had this same issue on Windows 10. I bypassed it by running the Docker daemon in experimental mode:

  1. Right click Docker icon in the Windows System Tray
  2. Go to Settings
  3. Daemon
  4. Advanced
  5. Set the "experimental": true
  6. Restart Docker

Using multiple .cpp files in c++ program?

In C/C++ you have header files (*.H). There you declare your functions/classes. So for example you will have to #include "second.h" to your main.cpp file.

In second.h you just declare like this void yourFunction(); In second.cpp you implement it like

void yourFunction() { 
   doSomethng(); 
}

Don't forget to #include "second.h" also in the beginning of second.cpp

Hope this helps:)

ReactJS: "Uncaught SyntaxError: Unexpected token <"

I have the same issue with you and I have change something in my server

you might try this

const root = require("path").join(__dirname, "./build");
app.use(express.static(root));
app.get("*", (req, res) => {
  res.sendFile("index.html", { root });
});

how to add value to combobox item

Instead of adding Reader("Name") you add a new ListItem. ListItem has a Text and a Value property that you can set.

Scanning Java annotations at runtime

And another solution is Google reflections.

Quick review:

  • Spring solution is the way to go if you're using Spring. Otherwise it's a big dependency.
  • Using ASM directly is a bit cumbersome.
  • Using Java Assist directly is clunky too.
  • Annovention is super lightweight and convenient. No maven integration yet.
  • Google reflections pulls in Google collections. Indexes everything and then is super fast.

how to transfer a file through SFTP in java?

Try this code.

public void send (String fileName) {
    String SFTPHOST = "host:IP";
    int SFTPPORT = 22;
    String SFTPUSER = "username";
    String SFTPPASS = "password";
    String SFTPWORKINGDIR = "file/to/transfer";

    Session session = null;
    Channel channel = null;
    ChannelSftp channelSftp = null;
    System.out.println("preparing the host information for sftp.");

    try {
        JSch jsch = new JSch();
        session = jsch.getSession(SFTPUSER, SFTPHOST, SFTPPORT);
        session.setPassword(SFTPPASS);
        java.util.Properties config = new java.util.Properties();
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        session.connect();
        System.out.println("Host connected.");
        channel = session.openChannel("sftp");
        channel.connect();
        System.out.println("sftp channel opened and connected.");
        channelSftp = (ChannelSftp) channel;
        channelSftp.cd(SFTPWORKINGDIR);
        File f = new File(fileName);
        channelSftp.put(new FileInputStream(f), f.getName());
        log.info("File transfered successfully to host.");
    } catch (Exception ex) {
        System.out.println("Exception found while tranfer the response.");
    } finally {
        channelSftp.exit();
        System.out.println("sftp Channel exited.");
        channel.disconnect();
        System.out.println("Channel disconnected.");
        session.disconnect();
        System.out.println("Host Session disconnected.");
    }
}   

What does print(... sep='', '\t' ) mean?

sep='\t' is often used for Tab-delimited file.

Best Python IDE on Linux

I haven't played around with it much but eclipse/pydev feels nice.

How can I set the default timezone in node.js?

Here's an answer for those deploying a Node.js application to Amazon AWS Elastic Beanstalk. I haven't seen this documented anywhere else:

Under Configuration -> Software -> Environment Properties, simply set the key value pair TZ and your time zone e.g. America/Los Angeles, and Apply the change.

You can verify the effect by outputting new Date().toString() in your Node app and paying attention to the time zone suffix.

The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>)

For those using Telerik as mentioned by Ovar, make sure you wrap your javascript in

 <telerik:RadScriptBlock ID="radSript1" runat="server">
   <script type="text/javascript">
        //Your javascript
   </script>
</telerik>

Since Telerik doesn't recognize <%# %> when looking for an element and <%= %> will give you an error if your javascript code isn't wrapped.

setImmediate vs. nextTick

In the comments in the answer, it does not explicitly state that nextTick shifted from Macrosemantics to Microsemantics.

before node 0.9 (when setImmediate was introduced), nextTick operated at the start of the next callstack.

since node 0.9, nextTick operates at the end of the existing callstack, whereas setImmediate is at the start of the next callstack

check out https://github.com/YuzuJS/setImmediate for tools and details

"UserWarning: Matplotlib is currently using agg, which is a non-GUI backend, so cannot show the figure." when plotting figure with pyplot on Pycharm

If you use Arch Linux (distributions like Manjaro or Antegros) simply type:

sudo pacman -S tk

And all will work perfectly!

Making a POST call instead of GET using urllib2

This may have been answered before: Python URLLib / URLLib2 POST.

Your server is likely performing a 302 redirect from http://myserver/post_service to http://myserver/post_service/. When the 302 redirect is performed, the request changes from POST to GET (see Issue 1401). Try changing url to http://myserver/post_service/.

Angular 5 Service to read local .json file

Assumes, you have a data.json file in the src/app folder of your project with the following values:

[
    {
        "id": 1,
        "name": "Licensed Frozen Hat",
        "description": "Incidunt et magni est ut.",
        "price": "170.00",
        "imageUrl": "https://source.unsplash.com/1600x900/?product",
        "quantity": 56840
    },
    ...
]

3 Methods for Reading Local JSON Files

Method 1: Reading Local JSON Files Using TypeScript 2.9+ import Statement

import { Component, OnInit } from '@angular/core';
import * as data from './data.json';

@Component({
  selector: 'app-root',
  template: `<ul>
      <li *ngFor="let product of products">

      </li>
  </ul>`,
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
  title = 'Angular Example';

  products: any = (data as any).default;

  constructor(){}
  ngOnInit(){
    console.log(data);
  }
}

Method 2: Reading Local JSON Files Using Angular HttpClient

import { Component, OnInit } from '@angular/core';
import { HttpClient } from "@angular/common/http";


@Component({
  selector: 'app-root',
  template: `<ul>
      <li *ngFor="let product of products">

      </li>
  </ul>`,
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
  title = 'Angular Example';
  products: any = [];

  constructor(private httpClient: HttpClient){}
  ngOnInit(){
    this.httpClient.get("assets/data.json").subscribe(data =>{
      console.log(data);
      this.products = data;
    })
  }
}

Method 3: Reading Local JSON Files in Offline Angular Apps Using ES6+ import Statement

If your Angular application goes offline, reading the JSON file with HttpClient will fail. In this case, we have one more method to import local JSON files using the ES6+ import statement which supports importing JSON files.

But first we need to add a typing file as follows:

declare module "*.json" {
  const value: any;
  export default value;
}

Add this inside a new file json-typings.d.ts file in the src/app folder.

Now, you can import JSON files just like TypeScript 2.9+.

import * as data from "data.json";

How to easily import multiple sql files into a MySQL database?

You could also a for loop to do so:

#!/bin/bash
for i in *.sql
do
    echo "Importing: $i"
    mysql your_db_name < $i
    wait
done 

Source

How to add line break for UILabel?

Just do it like this

NSString * strCheck = @"A\nB";

strCheck = [strCheck stringByReplacingOccurrencesOfString:@"\\n" withString:@"\n"];  //This is to prevent for fetching string from plist or data structure

label.numberOfLines = 0;

label.lineBreakMode = NSLineBreakByWordWrapping;

label.text = strCheck;

create a white rgba / CSS3

I believe

rgba( 0, 0, 0, 0.8 )

is equivalent in shade with #333.

Live demo: http://jsfiddle.net/8MVC5/1/

Where to find the complete definition of off_t type?

If you are having trouble tracing the definitions, you can use the preprocessed output of the compiler which will tell you all you need to know. E.g.

$ cat test.c
#include <stdio.h>
$ cc -E test.c | grep off_t
typedef long int __off_t;
typedef __off64_t __loff_t;
  __off_t __pos;
  __off_t _old_offset;
typedef __off_t off_t;
extern int fseeko (FILE *__stream, __off_t __off, int __whence);
extern __off_t ftello (FILE *__stream) ;

If you look at the complete output you can even see the exact header file location and line number where it was defined:

# 132 "/usr/include/bits/types.h" 2 3 4


typedef unsigned long int __dev_t;
typedef unsigned int __uid_t;
typedef unsigned int __gid_t;
typedef unsigned long int __ino_t;
typedef unsigned long int __ino64_t;
typedef unsigned int __mode_t;
typedef unsigned long int __nlink_t;
typedef long int __off_t;
typedef long int __off64_t;

...

# 91 "/usr/include/stdio.h" 3 4
typedef __off_t off_t;

How do I get into a Docker container's shell?

Another option is to use nsenter.

PID=$(docker inspect --format {{.State.Pid}} <container_name_or_ID>)
nsenter --target $PID --mount --uts --ipc --net --pid

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!]

jQuery find file extension (from string)

To get the file extension, I would do this:

var ext = file.split('.').pop();

Extracting extension from filename in Python

Any of the solutions above work, but on linux I have found that there is a newline at the end of the extension string which will prevent matches from succeeding. Add the strip() method to the end. For example:

import os.path
extension = os.path.splitext(filename)[1][1:].strip() 

"Sources directory is already netbeans project" error when opening a project from existing sources

Try to create a new empty project; then you can copy the public_html to the new project folder and it will appear .

How can I get client information such as OS and browser

This code is based on the most voted question but I might be easier to use

public enum OS {

    WINDOWS,
    MAC,
    LINUX,
    ANDROID,
    IPHONE,
    UNKNOWN;

    public static OS valueOf(HttpServletRequest request) {

        final String userAgent = request.getHeader("User-Agent");
        final OS toReturn;

        if (userAgent == null || userAgent.isEmpty()) {
            toReturn = UNKNOWN;
        } else if (userAgent.toLowerCase().contains("windows")) {
            toReturn = WINDOWS;
        } else if (userAgent.toLowerCase().contains("mac")) {
            toReturn = MAC;
        } else if (userAgent.toLowerCase().contains("x11")) {
            toReturn = LINUX;
        } else if (userAgent.toLowerCase().contains("android")) {
            toReturn = ANDROID;
        } else if (userAgent.toLowerCase().contains("iphone")) {
            toReturn = IPHONE;
        } else {
            toReturn = UNKNOWN;
        }

        return toReturn;
    }

}

How to increase number of threads in tomcat thread pool?

You would have to tune it according to your environment.

Sometimes it's more useful to increase the size of the backlog (acceptCount) instead of the maximum number of threads.

Say, instead of

<Connector ... maxThreads="500" acceptCount="50"

you use

<Connector ... maxThreads="300" acceptCount="150"

you can get much better performance in some cases, cause there would be less threads disputing the resources and the backlog queue would be consumed faster.

In any case, though, you have to do some benchmarks to really know what is best.

Creation timestamp and last update timestamp with Hibernate and MySQL

In case you are using the Session API the PrePersist and PreUpdate callbacks won't work according to this answer.

I am using Hibernate Session's persist() method in my code so the only way I could make this work was with the code below and following this blog post (also posted in the answer).

@MappedSuperclass
public abstract class AbstractTimestampEntity {

    @Temporal(TemporalType.TIMESTAMP)
    @Column(name = "created")
    private Date created=new Date();

    @Temporal(TemporalType.TIMESTAMP)
    @Column(name = "updated")
    @Version
    private Date updated;

    public Date getCreated() {
        return created;
    }

    public void setCreated(Date created) {
        this.created = created;
    }

    public Date getUpdated() {
        return updated;
    }

    public void setUpdated(Date updated) {
        this.updated = updated;
    }
}

ReactJS - .JS vs .JSX

As already mentioned, there is no difference, if you create a file with .jsx or .js.

I would like to bring another expect of creating the files as .jsx while creating a component.

This is not mandatory, but an architectural approach that we can follow. So, in large projects we divide our components as Presentational components or Container components. Just to brief, in container components we write the logic to get data for the component and render the Presentational component with props. In presentational components, we usually donot write functional logic, presentational components are used to represent the UI with required props.

So, if you check the definition on JSX in React documents.

It says,

const element = <h1>Hello, world!</h1>;

It is called JSX, and it is a syntax extension to JavaScript. 
We recommend using it with React to describe what the UI should look like. 
JSX may remind you of a template language, but it comes with the full power of JavaScript.

JSX produces React “elements”. Instead of artificially separating technologies by putting
markup and logic in separate files, React separates concerns with loosely coupled units 
called “components” that contain both. 

React doesn’t require using JSX, but most people find it helpful as a visual aid when 
working with UI inside the JavaScript code. It also allows React to show more useful 
error and warning messages.

It means, It's not mandatory but you can think of creating presentational components with '.jsx' as it actually binds the props with the UI. and container components, as .js files as those contains logic to get the data.

It's a convention that you can follow while creating the .jsx or .js files, to logically and physically separate the code.

Android splash screen image sizes to fit all devices

** If you are looking for screen details for all kind of major devices **

go to material.io

Windows batch: call more than one command in a FOR loop?

Using & is fine for short commands, but that single line can get very long very quick. When that happens, switch to multi-line syntax.

FOR /r %%X IN (*.txt) DO (
    ECHO %%X
    DEL %%X
)

Placement of ( and ) matters. The round brackets after DO must be placed on the same line, otherwise the batch file will be incorrect.

See if /?|find /V "" for details.

WaitAll vs WhenAll

As an example of the difference -- if you have a task the does something with the UI thread (e.g. a task that represents an animation in a Storyboard) if you Task.WaitAll() then the UI thread is blocked and the UI is never updated. if you use await Task.WhenAll() then the UI thread is not blocked, and the UI will be updated.

How can I get the external SD card path for Android 4.0+?

You can use something like - Context.getExternalCacheDirs() or Context.getExternalFilesDirs() or Context.getObbDirs(). They give application specific directories in all external storage devices where the application can store its files.

So something like this - Context.getExternalCacheDirs()[i].getParentFile().getParentFile().getParentFile().getParent() can get you the root path of external storage devices.

I know these commands are for a different purpose but other answers didn't work for me.

This link gave me good pointers - https://possiblemobile.com/2014/03/android-external-storage/

Apache error: _default_ virtualhost overlap on port 443

To resolve the issue on a Debian/Ubuntu system modify the /etc/apache2/ports.conf settings file by adding NameVirtualHost *:443 to it. My ports.conf is the following at the moment:

# /etc/apache/ports.conf
# If you just change the port or add more ports here, you will likely also
# have to change the VirtualHost statement in
# /etc/apache2/sites-enabled/000-default
# This is also true if you have upgraded from before 2.2.9-3 (i.e. from
# Debian etch). See /usr/share/doc/apache2.2-common/NEWS.Debian.gz and
# README.Debian.gz

NameVirtualHost *:80
Listen 80

<IfModule mod_ssl.c>
    # If you add NameVirtualHost *:443 here, you will also have to change
    # the VirtualHost statement in /etc/apache2/sites-available/default-ssl
    # to <VirtualHost *:443>
    # Server Name Indication for SSL named virtual hosts is currently not
    # supported by MSIE on Windows XP.

    NameVirtualHost *:443

    Listen 443
</IfModule>

<IfModule mod_gnutls.c>
    NameVirtualHost *:443
    Listen 443
</IfModule>

Furthermore ensure that 'sites-available/default-ssl' is not enabled, type a2dissite default-ssl to disable the site. While you're at it type a2dissite by itself to get a list and see if there is any other site settings that you have enabled that might be mapping onto port 443.

List of all special characters that need to be escaped in a regex

According to the String Literals / Metacharacters documentation page, they are:

<([{\^-=$!|]})?*+.>

Also it would be cool to have that list refereed somewhere in code, but I don't know where that could be...

selected value get from db into dropdown select box option using php mysql error

USING POD

<?php
$username = "root";
$password = "";
$db = "db_name";

$dns = "mysql:host=localhost;dbname=$db;charset=utf8mb4";
    $conn = new PDO($dns,$username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $sql = "select * from mine where username = ? ";

    $stmt1 = $conn->prepare($sql);
    $stmt1 -> execute(array($_POST['user']));
    $all = $stmt1->fetchAll(); ?>

    <div class="controls">
        <select  data-rel="chosen"  name="degree_id" id="selectError">

                 <?php foreach($all as $nt) { echo "<option value =$nt[id]>$nt[name]</option>";}?>
        </select>

    </div>

How can I check if a string contains ANY letters from the alphabet?

You can use regular expression like this:

import re

print re.search('[a-zA-Z]+',string)

Inserting data into a MySQL table using VB.NET

You need to use ?param instead of @param when performing queries to MySQL

 str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (?id,?m_id,?model,?color,?ch_id,?pt_num,?code)"
        sqlCommand.Connection = SQLConnection
        sqlCommand.CommandText = str_carSql
        sqlCommand.Parameters.AddWithValue("?id", TextBox20.Text)
        sqlCommand.Parameters.AddWithValue("?m_id", TextBox20.Text)
        sqlCommand.Parameters.AddWithValue("?model", TextBox23.Text)
        sqlCommand.Parameters.AddWithValue("?color", TextBox24.Text)
        sqlCommand.Parameters.AddWithValue("?ch_id", TextBox22.Text)
        sqlCommand.Parameters.AddWithValue("?pt_num", TextBox21.Text)
        sqlCommand.Parameters.AddWithValue("?code", ComboBox1.SelectedItem)
        sqlCommand.ExecuteNonQuery()

Change the catch block to see the actual exception:

  Catch ex As Exception
         MsgBox(ex.Message)   
          Return False

    End Try

Difference between shared objects (.so), static libraries (.a), and DLL's (.so)?

A static library(.a) is a library that can be linked directly into the final executable produced by the linker,it is contained in it and there is no need to have the library into the system where the executable will be deployed.

A shared library(.so) is a library that is linked but not embedded in the final executable, so will be loaded when the executable is launched and need to be present in the system where the executable is deployed.

A dynamic link library on windows(.dll) is like a shared library(.so) on linux but there are some differences between the two implementations that are related to the OS (Windows vs Linux) :

A DLL can define two kinds of functions: exported and internal. The exported functions are intended to be called by other modules, as well as from within the DLL where they are defined. Internal functions are typically intended to be called only from within the DLL where they are defined.

An SO library on Linux doesn't need special export statement to indicate exportable symbols, since all symbols are available to an interrogating process.

How to pass multiple values to single parameter in stored procedure

I think, below procedure help you to what you are looking for.

 CREATE PROCEDURE [dbo].[FindEmployeeRecord]
        @EmployeeID nvarchar(Max)
    AS
    BEGIN
    DECLARE @sqLQuery VARCHAR(MAX)
    Declare @AnswersTempTable Table
    (  
        EmpId int,         
        EmployeeName nvarchar (250),       
        EmployeeAddress nvarchar (250),  
        PostalCode nvarchar (50),
        TelephoneNo nvarchar (50),
        Email nvarchar (250),
        status nvarchar (50),  
        Sex nvarchar (50) 
    )

    Set @sqlQuery =
    'select e.EmpId,e.EmployeeName,e.Email,e.Sex,ed.EmployeeAddress,ed.PostalCode,ed.TelephoneNo,ed.status
    from Employee e
    join EmployeeDetail ed on e.Empid = ed.iEmpID
    where Convert(nvarchar(Max),e.EmpId) in ('+@EmployeeId+')
    order by EmpId'
    Insert into @AnswersTempTable
    exec (@sqlQuery)
    select * from @AnswersTempTable
    END

fitting data with numpy

Unfortunately, np.polynomial.polynomial.polyfit returns the coefficients in the opposite order of that for np.polyfit and np.polyval (or, as you used np.poly1d). To illustrate:

In [40]: np.polynomial.polynomial.polyfit(x, y, 4)
Out[40]: 
array([  84.29340848, -100.53595376,   44.83281408,   -8.85931101,
          0.65459882])

In [41]: np.polyfit(x, y, 4)
Out[41]: 
array([   0.65459882,   -8.859311  ,   44.83281407, -100.53595375,
         84.29340846])

In general: np.polynomial.polynomial.polyfit returns coefficients [A, B, C] to A + Bx + Cx^2 + ..., while np.polyfit returns: ... + Ax^2 + Bx + C.

So if you want to use this combination of functions, you must reverse the order of coefficients, as in:

ffit = np.polyval(coefs[::-1], x_new)

However, the documentation states clearly to avoid np.polyfit, np.polyval, and np.poly1d, and instead to use only the new(er) package.

You're safest to use only the polynomial package:

import numpy.polynomial.polynomial as poly

coefs = poly.polyfit(x, y, 4)
ffit = poly.polyval(x_new, coefs)
plt.plot(x_new, ffit)

Or, to create the polynomial function:

ffit = poly.Polynomial(coefs)    # instead of np.poly1d
plt.plot(x_new, ffit(x_new))

fit and data plot

How to set a primary key in MongoDB?

If you thinking like RDBMS, you can't create primary key. Default primary key is _id. But you can create Unique Index. Example is bellow.

db.members.createIndex( { "user_id": 1 }, { unique: true } )

db.members.insert({'user_id':1,'name':'nanhe'})

db.members.insert({'name':'kumar'})

db.members.find();

Output is bellow.

{ "_id" : ObjectId("577f9cecd71d71fa1fb6f43a"), "user_id" : 1, "name" : "nanhe" }

{ "_id" : ObjectId("577f9d02d71d71fa1fb6f43b"), "name" : "kumar" }

When you try to insert same user_id mongodb throws a write error.

db.members.insert({'user_id':1,'name':'aarush'})

WriteResult({ "nInserted" : 0, "writeError" : { "code" : 11000, "errmsg" : "E11000 duplicate key error collection: student.members index: user_id_1 dup key: { : 1.0 }" } })

What is a plain English explanation of "Big O" notation?

Big O describes an upper limit on the growth behaviour of a function, for example the runtime of a program, when inputs become large.

Examples:

  • O(n): If I double the input size the runtime doubles

  • O(n2): If the input size doubles the runtime quadruples

  • O(log n): If the input size doubles the runtime increases by one

  • O(2n): If the input size increases by one, the runtime doubles

The input size is usually the space in bits needed to represent the input.

CSS transition effect makes image blurry / moves image 1px, in Chrome?

filter: blur(0)
transition: filter .3s ease-out
transition-timing-function: steps(3, end) // add this string with steps equal duration

I was helped by setting the value of transition duration .3s equal transition timing steps .3s

How to use Visual Studio C++ Compiler?

In Visual Studio, you can't just open a .cpp file and expect it to run. You must create a project first, or open the .cpp in some existing project.

In your case, there is no project, so there is no project to build.

Go to File --> New --> Project --> Visual C++ --> Win32 Console Application. You can uncheck "create a directory for solution". On the next page, be sure to check "Empty project".

Then, You can add .cpp files you created outside the Visual Studio by right clicking in the Solution explorer on folder icon "Source" and Add->Existing Item.

Obviously You can create new .cpp this way too (Add --> New). The .cpp file will be created in your project directory.

Then you can press ctrl+F5 to compile without debugging and can see output on console window.

How can I compare two ordered lists in python?

The expression a == b should do the job.

Using Vim's tabs like buffers

This is an answer for those not familiar with Vim and coming from other text editors (in my case Sublime Text).

I read through all these answers and it still wasn't clear. If you read through them enough things begin to make sense, but it took me hours of going back and forth between questions.

The first thing is, as others have explained:

Tab Pages, sound a lot like tabs, they act like tabs and look a lot like tabs in most other GUI editors, but they're not. I think it's an a bad mental model that was built on in Vim, which unfortunately clouds the extra power that you have within a tab page.

The first description that I understood was from @crenate's answer is that they are the equivalent to multiple desktops. When seen in that regard you'd only ever have a couple of desktops open but have lots of GUI windows open within each one.

I would say they are similar to in other editors/browsers:

  1. Tab groupings
  2. Sublime Text workspaces (i.e. a list of the open files that you have in a project)

When you see them like that you realise the power of them that you can easily group sets of files (buffers) together e.g. your CSS files, your HTML files and your JS files in different tab pages. Which is actually pretty awesome.

Other descriptions that I find confusing

Viewport

This makes no sense to me. A viewport which although it does have a defined dictionary term, I've only heard referring to Vim windows in the :help window doc. Viewport is not a term I've ever heard with regards to editors like Sublime Text, Visual Studio, Atom, Notepad++. In fact I'd never heard about it for Vim until I started to try using tab pages.

If you view tab pages like multiple desktops, then referring to a desktop as a single window seems odd.

Workspaces

This possibly makes more sense, the dictionary definition is:

A memory storage facility for temporary use.

So it's like a place where you store a group of buffers.

I didn't initially sound like Sublime Text's concept of a workspace which is a list of all the files that you have open in your project:

the sublime-workspace file, which contains user specific data, such as the open files and the modifications to each.

However thinking about it more, this does actually agree. If you regard a Vim tab page like a Sublime Text project, then it would seem odd to have just one file open in each project and keep switching between projects. Hence why using a tab page to have open only one file is odd.

Collection of windows

The :help window refers to tab pages this way. Plus numerous other answers use the same concept. However until you get your head around what a vim window is, then that's not much use, like building a castle on sand.

As I referred to above, a vim window is the same as a viewport and quiet excellently explained in this linux.com article:

A really useful feature in Vim is the ability to split the viewable area between one or more files, or just to split the window to view two bits of the same file more easily. The Vim documentation refers to this as a viewport or window, interchangeably.

You may already be familiar with this feature if you've ever used Vim's help feature by using :help topic or pressing the F1 key. When you enter help, Vim splits the viewport and opens the help documentation in the top viewport, leaving your document open in the bottom viewport.

I find it odd that a tab page is referred to as a collection of windows instead of a collection of buffers. But I guess you can have two separate tab pages open each with multiple windows all pointing at the same buffer, at least that's what I understand so far.

Warnings Your Apk Is Using Permissions That Require A Privacy Policy: (android.permission.READ_PHONE_STATE)

The dependencies you have in your project, will add their own permissions. Please do the below to find from where "READ_PHONE_STATE" is coming.

  1. Rebuild your android application
  2. Press "Ctrl+Shift+F" in android studio (basically do a search all in the editor of your preference).
  3. Search for "READ_PHONE_STATE", you would find the entry in a regenerated manifest file (not the one you originally created). By the path of it you can know, from which dependency the permission is getting added. enter image description here

Comparing two arrays of objects, and exclude the elements who match values into new array in JS

I have searched a lot for a solution in which I can compare two array of objects with different attribute names (something like a left outer join). I came up with this solution. Here I used Lodash. I hope this will help you.

var Obj1 = [
    {id:1, name:'Sandra'},
    {id:2, name:'John'},   
];

var Obj2 = [
    {_id:2, name:'John'},
    {_id:4, name:'Bobby'}
];

var Obj3 = lodash.differenceWith(Obj1, Obj2, function (o1, o2) {
    return o1['id'] === o2['_id']
});

console.log(Obj3);
//  {id:1, name:'Sandra'}

What is limiting the # of simultaneous connections my ASP.NET application can make to a web service?

Might it be possible that you're using a WCF-based web service reference? By default, the ServiceThrottlingBehavior.MaxConcurrentCalls is 16.

You could try updating your service reference behavior's <serviceThrottling> element

<serviceThrottling
    maxConcurrentCalls="999" 
    maxConcurrentSessions="999" 
    maxConcurrentInstances="999" />

(Note that I'd recommend the settings above.) See MSDN for more information how to configure an appropriate <behavior> element.

POST an array from an HTML form without javascript

You can also post multiple inputs with the same name and have them save into an array by adding empty square brackets to the input name like this:

<input type="text" name="comment[]" value="comment1"/>
<input type="text" name="comment[]" value="comment2"/>
<input type="text" name="comment[]" value="comment3"/>
<input type="text" name="comment[]" value="comment4"/>

If you use php:

print_r($_POST['comment']) 

you will get this:

Array ( [0] => 'comment1' [1] => 'comment2' [2] => 'comment3' [3] => 'comment4' )

Entity Framework Core add unique constraint code-first

For someone who is trying all these solution but not working try this one, it worked for me

protected override void OnModelCreating(ModelBuilder builder)
{

    builder.Entity<User>().Property(t => t.Email).HasColumnAnnotation("Index", new IndexAnnotation(new IndexAttribute("IX_EmailIndex") { IsUnique = true }));

}

Writing an mp4 video using python opencv

What worked for me was to make sure the input 'frame' size is equal to output video's size (in this case, (680, 480) ).

http://answers.opencv.org/question/27902/how-to-record-video-using-opencv-and-python/

Here is my working code (Mac OSX Sierra 10.12.6):

cap = cv2.VideoCapture(0)
cap.set(3,640)
cap.set(4,480)

fourcc = cv2.VideoWriter_fourcc(*'MP4V')
out = cv2.VideoWriter('output.mp4', fourcc, 20.0, (640,480))

while(True):
    ret, frame = cap.read()
    out.write(frame)
    cv2.imshow('frame', frame)
    c = cv2.waitKey(1)
    if c & 0xFF == ord('q'):
        break

cap.release()
out.release()
cv2.destroyAllWindows()

Note: I installed openh264 as suggested by @10SecTom but I'm not sure if that was relevant to the problem.

Just in case:

brew install openh264

SOAP-UI - How to pass xml inside parameter

NOTE: This one is just an alternative for the previous provided .NET framework 3.5 and above

You can send it as raw xml

<test>or like this</test>

If you declare the paramater2 as XElement data type

ASP.NET Core 1.0 on IIS error 502.5

I changed profile options to this and it's working!!!

enter image description here

Maybe you should change this two options:

  1. Deployment Mode
  2. Target Runtime

Intent.putExtra List

 //To send from the activity that is calling another activity via myIntent

    myIntent.putExtra("id","10");
    startActivity(myIntent);

    //To receive from another Activity

            Bundle bundle = getIntent().getExtras();
            String id=bundle.getString("id");

To add server using sp_addlinkedserver

Add the linked server first with

exec sp_addlinkedserver
@server = 'SNRJDI\SLAMANAGEMENT',
@srvproduct=N'',
@provider=N'SQLNCLI'

See http://msdn.microsoft.com/en-us/library/ms190479.aspx

json call with C#

If your function resides in an mvc controller u can use the below code with a dictionary object of what you want to convert to json

Json(someDictionaryObj, JsonRequestBehavior.AllowGet);

Also try and look at system.web.script.serialization.javascriptserializer if you are using .net 3.5

as for your web request...it seems ok at first glance..

I would use something like this..

public void WebRequestinJson(string url, string postData)
    {
    StreamWriter requestWriter;

    var webRequest = System.Net.WebRequest.Create(url) as HttpWebRequest;
    if (webRequest != null)
    {
        webRequest.Method = "POST";
        webRequest.ServicePoint.Expect100Continue = false;
        webRequest.Timeout = 20000;

        webRequest.ContentType = "application/json";
        //POST the data.
        using (requestWriter = new StreamWriter(webRequest.GetRequestStream()))
        {
            requestWriter.Write(postData);
        }
    }
}

May be you can make the post and json string a parameter and use this as a generic webrequest method for all calls.

Rails 4: how to use $(document).ready() with turbo-links

Here's what I do... CoffeeScript:

ready = ->

  ...your coffeescript goes here...

$(document).ready(ready)
$(document).on('page:load', ready)

last line listens for page load which is what turbo links will trigger.

Edit...adding Javascript version (per request):

var ready;
ready = function() {

  ...your javascript goes here...

};

$(document).ready(ready);
$(document).on('page:load', ready);

Edit 2...For Rails 5 (Turbolinks 5) page:load becomes turbolinks:load and will be even fired on initial load. So we can just do the following:

$(document).on('turbolinks:load', function() {

  ...your javascript goes here...

});

Android SDK manager won't open

I installed Android Studio for Mac. I was not able to access the SDK manager through the IDE. It turns out I just had to have my JAVA_HOME environment variable set. Once I got this set I was able to launch the SDK manager.

how to pass this element to javascript onclick function and add a class to that clicked element

You can use addEventListener to pass this to a JavaScript function.

HTML

<button id="button">Year</button>

JavaScript

(function () {
    var btn = document.getElementById('button');
    btn.addEventListener('click', function () {
        Date('#year');
    }, false);
})();

 function Data(string)
          {
                $('.filter').removeClass('active');
                $(this).parent().addClass('active') ;
          } 

Sample database for exercise

Why not download the English Wikipedia? There are compressed SQL files of various sizes, and it should certainly be large enough for you

The main articles are XML, so inserting them into the db is a bit more of a problem, but you might find there are other files there that suit you. For example, the inter-page links SQL file is 2.3GB compressed. Have a look at https://en.wikipedia.org/wiki/Wikipedia:Database_download for more info.

Oskar

MySQL: Curdate() vs Now()

Just for the fun of it:

CURDATE() = DATE(NOW())

Or

NOW() = CONCAT(CURDATE(), ' ', CURTIME())

phpMyAdmin - The MySQL Extension is Missing

I had a similar issue, but it didn't help to add extension=mysql.so in my php.ini. It turned out that the mysql.so file was not in my extension folder nor anywhere else on my machine. Solved this by downloading the php source and building the extension manually and then copying it into the extension folder.

How do you append to a file?

The simplest way to append more text to the end of a file would be to use:

with open('/path/to/file', 'a+') as file:
    file.write("Additions to file")
file.close()

The a+ in the open(...) statement instructs to open the file in append mode and allows read and write access.

It is also always good practice to use file.close() to close any files that you have opened once you are done using them.

stdcall and cdecl

Raymond Chen gives a nice overview of what __stdcall and __cdecl does.

(1) The caller "knows" to clean up the stack after calling a function because the compiler knows the calling convention of that function and generates the necessary code.

void __stdcall StdcallFunc() {}

void __cdecl CdeclFunc()
{
    // The compiler knows that StdcallFunc() uses the __stdcall
    // convention at this point, so it generates the proper binary
    // for stack cleanup.
    StdcallFunc();
}

It is possible to mismatch the calling convention, like this:

LRESULT MyWndProc(HWND hwnd, UINT msg,
    WPARAM wParam, LPARAM lParam);
// ...
// Compiler usually complains but there's this cast here...
windowClass.lpfnWndProc = reinterpret_cast<WNDPROC>(&MyWndProc);

So many code samples get this wrong it's not even funny. It's supposed to be like this:

// CALLBACK is #define'd as __stdcall
LRESULT CALLBACK MyWndProc(HWND hwnd, UINT msg
    WPARAM wParam, LPARAM lParam);
// ...
windowClass.lpfnWndProc = &MyWndProc;

However, assuming the programmer doesn't ignore compiler errors, the compiler will generate the code needed to clean up the stack properly since it'll know the calling conventions of the functions involved.

(2) Both ways should work. In fact, this happens quite frequently at least in code that interacts with the Windows API, because __cdecl is the default for C and C++ programs according to the Visual C++ compiler and the WinAPI functions use the __stdcall convention.

(3) There should be no real performance difference between the two.

.gitignore is ignored by Git

There's another issue with .gitignore that might happen, especially for a Windows user. Git does not like it when you name .gitignore (such as unity.gitignore).

You'll want to always name it .gitignore, or on Windows, .gitignore. as Windows thinks you are trying to rename it without a filename.

Python: instance has no attribute

Your class doesn't have a __init__(), so by the time it's instantiated, the attribute atoms is not present. You'd have to do C.setdata('something') so C.atoms becomes available.

>>> C = Residues()
>>> C.atoms.append('thing')

Traceback (most recent call last):
  File "<pyshell#84>", line 1, in <module>
    B.atoms.append('thing')
AttributeError: Residues instance has no attribute 'atoms'

>>> C.setdata('something')
>>> C.atoms.append('thing')   # now it works
>>> 

Unlike in languages like Java, where you know at compile time what attributes/member variables an object will have, in Python you can dynamically add attributes at runtime. This also implies instances of the same class can have different attributes.

To ensure you'll always have (unless you mess with it down the line, then it's your own fault) an atoms list you could add a constructor:

def __init__(self):
    self.atoms = []

Insert Unicode character into JavaScript

Although @ruakh gave a good answer, I will add some alternatives for completeness:

You could in fact use even var Omega = '&#937;' in JavaScript, but only if your JavaScript code is:

  • inside an event attribute, as in onclick="var Omega = '&#937'; alert(Omega)" or
  • in a script element inside an XHTML (or XHTML + XML) document served with an XML content type.

In these cases, the code will be first (before getting passed to the JavaScript interpreter) be parsed by an HTML parser so that character references like &#937; are recognized. The restrictions make this an impractical approach in most cases.

You can also enter the O character as such, as in var Omega = 'O', but then the character encoding must allow that, the encoding must be properly declared, and you need software that let you enter such characters. This is a clean solution and quite feasible if you use UTF-8 encoding for everything and are prepared to deal with the issues created by it. Source code will be readable, and reading it, you immediately see the character itself, instead of code notations. On the other hand, it may cause surprises if other people start working with your code.

Using the \u notation, as in var Omega = '\u03A9', works independently of character encoding, and it is in practice almost universal. It can however be as such used only up to U+FFFF, i.e. up to \uffff, but most characters that most people ever heard of fall into that area. (If you need “higher” characters, you need to use either surrogate pairs or one of the two approaches above.)

You can also construct a character using the String.fromCharCode() method, passing as a parameter the Unicode number, in decimal as in var Omega = String.fromCharCode(937) or in hexadecimal as in var Omega = String.fromCharCode(0x3A9). This works up to U+FFFF. This approach can be used even when you have the Unicode number in a variable.

Eliminating NAs from a ggplot

From my point of view this error "Error: Aesthetics must either be length one, or the same length as the data" refers to the argument aes(x,y) I tried the na.omit() and worked just fine to me.

How to split() a delimited string to a List<String>

This will read a csv file and it includes a csv line splitter that handles double quotes and it can read even if excel has it open.

    public List<Dictionary<string, string>> LoadCsvAsDictionary(string path)
    {
        var result = new List<Dictionary<string, string>>();

        var fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
        System.IO.StreamReader file = new System.IO.StreamReader(fs);

        string line;

        int n = 0;
        List<string> columns = null;
        while ((line = file.ReadLine()) != null)
        {
            var values = SplitCsv(line);
            if (n == 0)
            {
                columns = values;
            }
            else
            {
                var dict = new Dictionary<string, string>();
                for (int i = 0; i < columns.Count; i++)
                    if (i < values.Count)
                        dict.Add(columns[i], values[i]);
                result.Add(dict);
            }
            n++;
        }

        file.Close();
        return result;
    }

    private List<string> SplitCsv(string csv)
    {
        var values = new List<string>();

        int last = -1;
        bool inQuotes = false;

        int n = 0;
        while (n < csv.Length)
        {
            switch (csv[n])
            {
                case '"':
                    inQuotes = !inQuotes;
                    break;
                case ',':
                    if (!inQuotes)
                    {
                        values.Add(csv.Substring(last + 1, (n - last)).Trim(' ', ','));
                        last = n;
                    }
                    break;
            }
            n++;
        }

        if (last != csv.Length - 1)
            values.Add(csv.Substring(last + 1).Trim());

        return values;
    }

Difference between Iterator and Listiterator?

the following is that the difference between iterator and listIterator

iterator :

boolean hasNext();
E next();
void remove();

listIterator:

boolean hasNext();
E next();
boolean hasPrevious();
E previous();
int nextIndex();
int previousIndex();
void remove();
void set(E e);
void add(E e);

How to stop (and restart) the Rails Server?

I had to restart the rails application on the production so I looked for an another answer. I have found it below:

http://wiki.ocssolutions.com/Restarting_a_Rails_Application_Using_Passenger

'tuple' object does not support item assignment

A tuple is immutable and thus you get the error you posted.

>>> pixels = [1, 2, 3]
>>> pixels[0] = 5
>>> pixels = (1, 2, 3)
>>> pixels[0] = 5
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'tuple' object does not support item assignment

In your specific case, as correctly pointed out in other answers, you should write:

pixel = (pixel[0] + 20, pixel[1], pixel[2])

How to Solve the XAMPP 1.7.7 - PHPMyAdmin - MySQL Error #2002 in Ubuntu

It turns out that the solution is to stop all the related services and solve the “Another daemon is already running” issue.

The commands i used to solve the issue are as follows:

sudo /opt/lampp/lampp stop              
sudo /etc/init.d/apache2 stop    
sudo /etc/init.d/mysql stop

Or, you can also type instead:

sudo service apache2 stop
sudo service mysql stop

After that, we again start the lampp services:

sudo /opt/lampp/lampp start

Now, there must be no problems while opening:

http://localhost                  
http://localhost/phpmyadmin

Edit line thickness of CSS 'underline' attribute

My Solution : https://codepen.io/SOLESHOE/pen/QqJXYj

{
    display: inline-block;
    border-bottom: 1px solid;
    padding-bottom: 0;
    line-height: 70%;
}

You can adjust underline position with line-height value, underline thickness and style with border-bottom.

Beware to disable default underline behavior if you want to underline an href.

How to use tick / checkmark symbol (?) instead of bullets in unordered list?

As an addition to the solution:

ul li:before {
 content: '?'; 
}

You can use any SVG icon as the content, such as the Font Aswesome.

enter image description here

_x000D_
_x000D_
ul {_x000D_
  list-style: none;_x000D_
  padding-left: 0;_x000D_
}_x000D_
li {_x000D_
  position: relative;_x000D_
  padding-left: 1.5em;  /* space to preserve indentation on wrap */_x000D_
}_x000D_
li:before {_x000D_
  content: '';  /* placeholder for the SVG */_x000D_
  position: absolute;_x000D_
  left: 0;  /* place the SVG at the start of the padding */_x000D_
  width: 1em;_x000D_
  height: 1em;_x000D_
  background: url("data:image/svg+xml;utf8,<?xml version='1.0' encoding='utf-8'?><svg width='18' height='18' viewBox='0 0 1792 1792' xmlns='http://www.w3.org/2000/svg'><path d='M1671 566q0 40-28 68l-724 724-136 136q-28 28-68 28t-68-28l-136-136-362-362q-28-28-28-68t28-68l136-136q28-28 68-28t68 28l294 295 656-657q28-28 68-28t68 28l136 136q28 28 28 68z'/></svg>") no-repeat;_x000D_
}
_x000D_
<ul>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>This is my text, it's pretty long so it needs to wrap. Note that wrapping preserves the indentation that bullets had!</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Note: To solve the wrapping problem that other answers had:

  • we reserve 1.5m ems of space at the left of each <li>
  • then position the SVG at the start of that space (position: absolute; left: 0)

Here are more Font Awesome black icons.

Check this CODEPEN to see how you can add colors and change their size.

TypeError: unsupported operand type(s) for /: 'str' and 'str'

I would have written:

percent = 100
while True:
     try:
        pyc = int(input('enter pyc :'))
        tpy = int(input('enter tpy:'))
        percent = (pyc / tpy) * percent
        break
     except ZeroDivisionError as detail:
        print 'Handling run-time error:', detail

Ignore parent padding

For image purpose you can do something like this

img {
    width: calc(100% + 20px); // twice the value of the parent's padding
    margin-left: -10px; // -1 * parent's padding
}

Do I use <img>, <object>, or <embed> for SVG files?

You can insert a SVG indirectly using <img> HTML tag and this is possible on StackOverflow following what is described below:

I have following SVG file on my PC

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="350" height="350" viewBox="0 0 350 350">

  <title>SVG 3 Circles Intersection </title>

    <circle cx="110" cy="110" r="100"
            stroke="red"
            stroke-width="3"
            fill="none"
            />
    <text x="110" y="110" 
          text-anchor="middle"
          stroke="red"
          stroke-width="1px"
          > Label
    </text>
    <circle cx="240" cy="110" r="100" 
            stroke="blue" 
            stroke-width="3"
            fill="none"
            />
    <text x="240" y="110" 
          text-anchor="middle" 
          stroke="blue" 
          stroke-width="1px"
          > Ticket
    </text>
    <circle cx="170" cy="240" r="100" 
            stroke="green" 
            stroke-width="3" 
            fill="none"
            />
    <text x="170" y="240" 
          text-anchor="middle" 
          stroke="green" 
          stroke-width="1px"
          > Vecto
    </text>
</svg>

I have uploaded this image to https://svgur.com

After upload was terminated, I have obtained following URL:

https://svgshare.com/i/RJV.svg

I have then MANUALLY (without using IMAGE icon) added following html tag

<img src="https://svgshare.com/i/KJV.svg"/>

and the result is just below

For user with some doubt, it is possible to see what I have done in editing following answer on StackOverflow inserting SVG image

REMARK-1: the SVG file must contains <?xml?> element. At begin, I have simply created a SVG file that begins directly with <svg> tag and nothing worked !

REMARK-2: at begin, I have tried to insert an image using IMAGE icon of Edit Toolbar. I paste URL of my SVG file but StackOverflow don't accept this method. The <img> tag must be added manually.

I hope that this answer can help other users.

Set Background color programmatically

If you save color code in the colors.xml which is under the values folder,then you should call the following:

root.setBackgroundColor(getResources().getColor(R.color.name));

name means you declare in the <color/> tag.

Command to get time in milliseconds

When you use GNU AWK since version 4.1, you can load the time library and do:

$ awk '@load "time"; BEGIN{printf "%.6f", gettimeofday()}'

This will print the current time in seconds since 1970-01-01T00:00:00 in sub second accuracy.

the_time = gettimeofday() Return the time in seconds that has elapsed since 1970-01-01 UTC as a floating-point value. If the time is unavailable on this platform, return -1 and set ERRNO. The returned time should have sub-second precision, but the actual precision may vary based on the platform. If the standard C gettimeofday() system call is available on this platform, then it simply returns the value. Otherwise, if on MS-Windows, it tries to use GetSystemTimeAsFileTime().

source: GNU awk manual

On Linux systems, the standard C function getimeofday() returns the time in microsecond accuracy.

json_encode/json_decode - returns stdClass instead of Array in PHP

tl;dr: JavaScript doesn't support associative arrays, therefore neither does JSON.

After all, it's JSON, not JSAAN. :)

So PHP has to convert your array into an object in order to encode into JSON.

Could not load type 'System.Runtime.CompilerServices.ExtensionAttribute' from assembly 'mscorlib

We ran into this problem and tracked it down to the Geocoding.net NuGet package that we were using to help with our Google Maps views (Geocoding.net version 3.1.0 published 2/4/2014).

The Geocoding dll appears to be .Net 4.0 when you examine the package file or view it using Jet Brains’ Dot Peek application; however, a colleague of mine says that it was compiled using ilmerge so it is most likely related to the ilmerge problems listed above.

It was a long process to track it down. We fetched different changesets from TFS till we narrowed it down to the changeset that added the aforementioned NuGet package. After removing it, we were able to deploy to our .NET 4 server.

Including all the jars in a directory within the Java classpath

You need to add them all separately. Alternatively, if you really need to just specify a directory, you can unjar everything into one dir and add that to your classpath. I don't recommend this approach however as you risk bizarre problems in classpath versioning and unmanagability.

How to install an apk on the emulator in Android Studio?

EDIT: Even though this answer is marked as the correct answer (in 2013), currently, as answered by @user2511630 below, you can drag-n-drop apk files directly into the emulator to install them.


Original Answer:

You can install .apk files to emulator regardless of what you are using (Eclipse or Android Studio)

here's what I always do: (For full beginners)

1- Run the emulator, and wait until it's completely started.

2- Go to your sdk installation folder then go to platform-tools (you should see an executable called adb.exe)

3- create a new file and call it run.bat, edit the file with notepad and write CMD in it and save it.

4- copy your desired apk to the same folder

5- now open run.bat and write adb install "your_apk_file.apk"

6- wait until the installation is complete

7- voila your apk is installed to your emulator.

Note: to re-install the application if it already existe use adb install -r "your_apk_file.apk"

sorry for the detailed instruction as I said for full beginners

Hope this help.

Regards,

Tarek

Example 1

Example 2

Fastest way to convert JavaScript NodeList to Array?

The results will completely depend on the browser, to give an objective verdict, we have to make some performance tests, here are some results, you can run them here:

Chrome 6:

Firefox 3.6:

Firefox 4.0b2:

Safari 5:

IE9 Platform Preview 3:

Remove the last three characters from a string

I read through all these, but wanted something a bit more elegant. Just to remove a certain number of characters from the end of a string:

string.Concat("hello".Reverse().Skip(3).Reverse());

output:

"he"

How to position two divs horizontally within another div

Via Bootstrap Grid, you can easily get the cross browser compatible solution.

<div class="container">     
  <div class="row">
    <div class="col-sm-6" style="background-color:lavender;">
      Div1       
    </div>
    <div class="col-sm-6" style="background-color:lavenderblush;">
          Div2
    </div>
  </div>
</div>

jsfiddle: http://jsfiddle.net/DTcHh/4197/

How do I select child elements of any depth using XPath?

//form/descendant::input[@type='submit']

How do I get PHP errors to display?

If you have Xdebug installed you can override every setting by setting:

xdebug.force_display_errors = 1;
xdebug.force_error_reporting = -1;

force_display_errors

Type: int, Default value: 0, Introduced in Xdebug >= 2.3 If this setting is set to 1 then errors will always be displayed, no matter what the setting of PHP's display_errors is.

force_error_reporting

Type: int, Default value: 0, Introduced in Xdebug >= 2.3 This setting is a bitmask, like error_reporting. This bitmask will be logically ORed with the bitmask represented by error_reporting to dermine which errors should be displayed. This setting can only be made in php.ini and allows you to force certain errors from being shown no matter what an application does with ini_set().

React Router Pass Param to Component

if you are using class component, you are most likely to use GSerjo suggestion. Pass in the params via <Route> props to your target component:

exact path="/problem/:problemId" render={props => <ProblemPage {...props.match.params} />}

Eloquent Collection: Counting and Detect Empty

When using ->get() you cannot simply use any of the below:

if (empty($result)) { }
if (!$result) { }
if ($result) { }

Because if you dd($result); you'll notice an instance of Illuminate\Support\Collection is always returned, even when there are no results. Essentially what you're checking is $a = new stdClass; if ($a) { ... } which will always return true.

To determine if there are any results you can do any of the following:

if ($result->first()) { } 
if (!$result->isEmpty()) { }
if ($result->count()) { }
if (count($result)) { }

You could also use ->first() instead of ->get() on the query builder which will return an instance of the first found model, or null otherwise. This is useful if you need or are expecting only one result from the database.

$result = Model::where(...)->first();
if ($result) { ... }

Notes / References

Bonus Information

The Collection and the Query Builder differences can be a bit confusing to newcomers of Laravel because the method names are often the same between the two. For that reason it can be confusing to know what one you’re working on. The Query Builder essentially builds a query until you call a method where it will execute the query and hit the database (e.g. when you call certain methods like ->all() ->first() ->lists() and others). Those methods also exist on the Collection object, which can get returned from the Query Builder if there are multiple results. If you're not sure what class you're actually working with, try doing var_dump(User::all()) and experimenting to see what classes it's actually returning (with help of get_class(...)). I highly recommend you check out the source code for the Collection class, it's pretty simple. Then check out the Query Builder and see the similarities in function names and find out when it actually hits the database.

How can I list all commits that changed a specific file?

Alternatively (since Git 1.8.4), it is also possible to just get all the commits which has changed a specific part of a file. You can get this by passing the starting line and the ending line number.

The result returned would be the list of commits that modified this particular part. The command goes like:

git log --pretty=short -u -L <upperLimit>,<lowerLimit>:<path_to_filename>

where upperLimit is the start_line_number and lowerLimit is the ending_line_number

More Info - https://www.techpurohit.com/list-some-useful-git-commands

What does "Changes not staged for commit" mean

What worked for me was to go to the root folder, where .git/ is. I was inside one the child folders and got there error.

What are the correct version numbers for C#?

C# language version history:

These are the versions of C# known about at the time of this writing:

In response to the OP's question:

What are the correct version numbers for C#? What came out when? Why can't I find any answers about C# 3.5?

There is no such thing as C# 3.5 - the cause of confusion here is that the C# 3.0 is present in .NET 3.5. The language and framework are versioned independently, however - as is the CLR, which is at version 2.0 for .NET 2.0 through 3.5, .NET 4 introducing CLR 4.0, service packs notwithstanding. The CLR in .NET 4.5 has various improvements, but the versioning is unclear: in some places it may be referred to as CLR 4.5 (this MSDN page used to refer to it that way, for example), but the Environment.Version property still reports 4.0.xxx.

As of May 3, 2017, the C# Language Team created a history of C# versions and features on their GitHub repository: Features Added in C# Language Versions. There is also a page that tracks upcoming and recently implemented language features.

Java 8 stream reverse order

For reference I was looking at the same problem, I wanted to join the string value of stream elements in the reverse order.

itemList = { last, middle, first } => first,middle,last

I started to use an intermediate collection with collectingAndThen from comonad or the ArrayDeque collector of Stuart Marks, although I wasn't happy with intermediate collection, and streaming again

itemList.stream()
        .map(TheObject::toString)
        .collect(Collectors.collectingAndThen(Collectors.toList(),
                                              strings -> {
                                                      Collections.reverse(strings);
                                                      return strings;
                                              }))
        .stream()
        .collect(Collector.joining());

So I iterated over Stuart Marks answer that was using the Collector.of factory, that has the interesting finisher lambda.

itemList.stream()
        .collect(Collector.of(StringBuilder::new,
                             (sb, o) -> sb.insert(0, o),
                             (r1, r2) -> { r1.insert(0, r2); return r1; },
                             StringBuilder::toString));

Since in this case the stream is not parallel, the combiner is not relevant that much, I'm using insert anyway for the sake of code consistency but it does not matter as it would depend of which stringbuilder is built first.

I looked at the StringJoiner, however it does not have an insert method.

jQuery remove selected option from this

This should do the trick:

$('#some_select_box').click(function() {
  $('option:selected', this ).remove();
});

jquery multiple checkboxes array

If you have a class for each of your input box, then you can do it as

        var checked = []
        $('input.Booking').each(function ()
        {
            checked.push($(this).val());
        });

Error importing SQL dump into MySQL: Unknown database / Can't create database

It sounds like your database dump includes the information for creating the database. So don't give the MySQL command line a database name. It will create the new database and switch to it to do the import.

How to remove numbers from a string?

Very close, try:

questionText = questionText.replace(/[0-9]/g, '');

replace doesn't work on the existing string, it returns a new one. If you want to use it, you need to keep it!
Similarly, you can use a new variable:

var withNoDigits = questionText.replace(/[0-9]/g, '');

One last trick to remove whole blocks of digits at once, but that one may go too far:

questionText = questionText.replace(/\d+/g, '');

Propagate all arguments in a bash shell script

#!/usr/bin/env bash
while [ "$1" != "" ]; do
  echo "Received: ${1}" && shift;
done;

Just thought this may be a bit more useful when trying to test how args come into your script

How might I extract the property values of a JavaScript object into an array?

ES2017 using Object.values:

_x000D_
_x000D_
const dataObject = {_x000D_
    object1: {_x000D_
        id: 1,_x000D_
        name: "Fred"_x000D_
    },_x000D_
    object2: {_x000D_
        id: 2,_x000D_
        name: "Wilma"_x000D_
    },_x000D_
    object3: {_x000D_
        id: 3,_x000D_
        name: "Pebbles"_x000D_
    }_x000D_
};_x000D_
_x000D_
const valuesOnly = Object.values(dataObject);_x000D_
_x000D_
console.log(valuesOnly)
_x000D_
_x000D_
_x000D_

How do I get the Back Button to work with an AngularJS ui-router state machine?

app.run(['$window', '$rootScope', 
function ($window ,  $rootScope) {
  $rootScope.goBack = function(){
    $window.history.back();
  }
}]);

<a href="#" ng-click="goBack()">Back</a>

How do I remove a key from a JavaScript object?

The delete operator allows you to remove a property from an object.

The following examples all do the same thing.

// Example 1
var key = "Cow";
delete thisIsObject[key]; 

// Example 2
delete thisIsObject["Cow"];

// Example 3
delete thisIsObject.Cow;

If you're interested, read Understanding Delete for an in-depth explanation.

Create database from command line

createdb is a command line utility which you can run from bash and not from psql. To create a database from psql, use the create database statement like so:

create database [databasename];

Note: be sure to always end your SQL statements with ;

Easiest way to convert a List to a Set in Java

Set<E> alphaSet  = new HashSet<E>(<your List>);

or complete example

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class ListToSet
{
    public static void main(String[] args)
    {
        List<String> alphaList = new ArrayList<String>();
        alphaList.add("A");
        alphaList.add("B");
        alphaList.add("C");
        alphaList.add("A");
        alphaList.add("B");
        System.out.println("List values .....");
        for (String alpha : alphaList)
        {
            System.out.println(alpha);
        }
        Set<String> alphaSet = new HashSet<String>(alphaList);
        System.out.println("\nSet values .....");
        for (String alpha : alphaSet)
        {
            System.out.println(alpha);
        }
    }
}

Resource interpreted as stylesheet but transferred with MIME type text/html (seems not related with web server)

I was facing similar issue. And Exploring solutions in this fantastic Stack Overflow page.

user54861 's response (mismatching names in case sensetivity) makes me curious to inspect my code again and realized that "I didnt upload two js files that I loaded them in head tag". :-)

When I uploaded them the issue runs away ! And code runs and page rendered without any another error!

So, moral of the story is don't forget to make sure that all of your js files are uploaded where the page is looking for them.

Drawing Isometric game worlds

Coobird's answer is the correct, complete one. However, I combined his hints with those from another site to create code that works in my app (iOS/Objective-C), which I wanted to share with anyone who comes here looking for such a thing. Please, if you like/up-vote this answer, do the same for the originals; all I did was "stand on the shoulders of giants."

As for sort-order, my technique is a modified painter's algorithm: each object has (a) an altitude of the base (I call "level") and (b) an X/Y for the "base" or "foot" of the image (examples: avatar's base is at his feet; tree's base is at it's roots; airplane's base is center-image, etc.) Then I just sort lowest to highest level, then lowest (highest on-screen) to highest base-Y, then lowest (left-most) to highest base-X. This renders the tiles the way one would expect.

Code to convert screen (point) to tile (cell) and back:

typedef struct ASIntCell {  // like CGPoint, but with int-s vice float-s
    int x;
    int y;
} ASIntCell;

// Cell-math helper here:
//      http://gamedevelopment.tutsplus.com/tutorials/creating-isometric-worlds-a-primer-for-game-developers--gamedev-6511
// Although we had to rotate the coordinates because...
// X increases NE (not SE)
// Y increases SE (not SW)
+ (ASIntCell) cellForPoint: (CGPoint) point
{
    const float halfHeight = rfcRowHeight / 2.;

    ASIntCell cell;
    cell.x = ((point.x / rfcColWidth) - ((point.y - halfHeight) / rfcRowHeight));
    cell.y = ((point.x / rfcColWidth) + ((point.y + halfHeight) / rfcRowHeight));

    return cell;
}


// Cell-math helper here:
//      http://stackoverflow.com/questions/892811/drawing-isometric-game-worlds/893063
// X increases NE,
// Y increases SE
+ (CGPoint) centerForCell: (ASIntCell) cell
{
    CGPoint result;

    result.x = (cell.x * rfcColWidth  / 2) + (cell.y * rfcColWidth  / 2);
    result.y = (cell.y * rfcRowHeight / 2) - (cell.x * rfcRowHeight / 2);

    return result;
}

Default Activity not found in Android Studio

  1. In Android Studio

  2. Go to edit Configuration .

  3. Select the app.

  4. choose the lunch Activity path.

  5. apply, OK.

    Thanks!!

Node.js: get path from the request

simply call req.url. that should do the work. you'll get something like /something?bla=foo

How to find count of Null and Nan values for each column in a PySpark dataframe efficiently?

I prefer this solution:

df = spark.table(selected_table).filter(condition)

counter = df.count()

df = df.select([(counter - count(c)).alias(c) for c in df.columns])

How to uncommit my last commit in Git

If you commit to the wrong branch

While on the wrong branch:

  1. git log -2 gives you hashes of 2 last commits, let's say $prev and $last
  2. git checkout $prev checkout correct commit
  3. git checkout -b new-feature-branch creates a new branch for the feature
  4. git cherry-pick $last patches a branch with your changes

Then you can follow one of the methods suggested above to remove your commit from the first branch.

What is the difference between "is None" and "== None"

In this case, they are the same. None is a singleton object (there only ever exists one None).

is checks to see if the object is the same object, while == just checks if they are equivalent.

For example:

p = [1]
q = [1]
p is q # False because they are not the same actual object
p == q # True because they are equivalent

But since there is only one None, they will always be the same, and is will return True.

p = None
q = None
p is q # True because they are both pointing to the same "None"

How to check if an element is visible with WebDriver

Short answer: use #visibilityOfElementLocated

None of the answers using isDisplayed or similar are correct. They only check if the display property is not none, not if the element can actually be seen! Selenium had a bunch of static utility methods added in the ExpectedConditions class. Two of them can be used in this case:

Usage

@Test
// visibilityOfElementLocated has been statically imported
public demo(){
    By searchButtonSelector = By.className("search_button");
    WebDriverWait wait = new WebDriverWait(driver, 10);
    driver.get(homeUrl);

    WebElement searchButton = wait.until(                
            visibilityOfElementLocated
            (searchButtonSelector)); 

    //clicks the search button 
    searchButton.click();

Custom visibility check running on the client

This was my answer before finding out about the utility methods on ExpectedConditions. It might still be relevant, as I assume it does more than the method mentioned above, which only checks the element has a height and a width.

In essence: this cannot be answered by Java and the findElementBy* methods and WebElement#isDisplayed alone, as they can only tell you if an element exists, not if it is actually visible. The OP hasn't defined what visible means, but it normally entails

  • it has an opacity > 0
  • it has the display property set to something else than none
  • the visibility prop is set to visible
  • there are no other elements hiding it (it's the topmost element)

Most people would also include the requirement that it is actually within the viewport as well (so a person would be able to see it).

For some reason, this quite normal need is not met by the pure Java API, while front-ends to Selenium that builds upon it often implements some variation of isVisible, which is why I knew this should be possible. And after browsing the source of the Node framework WebDriver.IO I found the source of isVisible, which is now renamed to the more aptly name of isVisibleInViewport in the 5.0-beta.

Basically, they implement the custom command as a call that delegates to a javascript that runs on the client and does the actual work! This is the "server" bit:

export default function isDisplayedInViewport () {
    return getBrowserObject(this).execute(isDisplayedInViewportScript, {
        [ELEMENT_KEY]: this.elementId, // w3c compatible
        ELEMENT: this.elementId // jsonwp compatible
    })
}

So the interesting bit is the javascript sent to run on the client:

/**
 * check if element is visible and within the viewport
 * @param  {HTMLElement} elem  element to check
 * @return {Boolean}           true if element is within viewport
 */
export default function isDisplayedInViewport (elem) {
    const dde = document.documentElement

    let isWithinViewport = true
    while (elem.parentNode && elem.parentNode.getBoundingClientRect) {
        const elemDimension = elem.getBoundingClientRect()
        const elemComputedStyle = window.getComputedStyle(elem)
        const viewportDimension = {
            width: dde.clientWidth,
            height: dde.clientHeight
        }

        isWithinViewport = isWithinViewport &&
                           (elemComputedStyle.display !== 'none' &&
                            elemComputedStyle.visibility === 'visible' &&
                            parseFloat(elemComputedStyle.opacity, 10) > 0 &&
                            elemDimension.bottom > 0 &&
                            elemDimension.right > 0 &&
                            elemDimension.top < viewportDimension.height &&
                            elemDimension.left < viewportDimension.width)

        elem = elem.parentNode
    }

    return isWithinViewport
}

This piece of JS can actually be copied (almost) verbatim into your own codebase (remove export default and replace const with var in case of non-evergreen browsers)! To use it, read it from File into a String that can be sent by Selenium for running on the client.

Another interesting and related script that might be worth looking into is selectByVisibleText.

If you haven't executed JS using Selenium before you could have a small peek into this or browse the JavaScriptExecutor API.

Usually, try to always use non-blocking async scripts (meaning #executeAsyncScript), but since we already have a synchronous, blocking script we might as well use the normal sync call. The returned object can be many types of Object, so cast approprately. This could be one way of doing it:

/** 
 * Demo of a java version of webdriverio's isDisplayedInViewport
 * https://github.com/webdriverio/webdriverio/blob/v5.0.0-beta.2/packages/webdriverio/src/commands/element/isDisplayedInViewport.js
 * The super class GuiTest just deals with setup of the driver and such
 */
class VisibleDemoTest extends GuiTest {
    public static String readScript(String name) {
        try {
            File f = new File("selenium-scripts/" + name + ".js");
            BufferedReader reader = new BufferedReader( new FileReader( file ) );
            return reader.lines().collect(Collectors.joining(System.lineSeparator()));
        } catch(IOError e){
            throw new RuntimeError("No such Selenium script: " + f.getAbsolutePath()); 
        }
    }

    public static Boolean isVisibleInViewport(RemoteElement e){
        // according to the Webdriver spec a string that identifies an element
        // should be deserialized into the corresponding web element,
        // meaning the 'isDisplayedInViewport' function should receive the element, 
        // not just the string we passed to it originally - how this is done is not our concern
        //
        // This is probably when ELEMENT and ELEMENT_KEY refers to in the wd.io implementation
        //
        // Ref https://w3c.github.io/webdriver/#dfn-json-deserialize
        return js.executeScript(readScript("isDisplayedInViewport"), e.getId());
    }

    public static Boolean isVisibleInViewport(String xPath){
        driver().findElementByXPath("//button[@id='should_be_visible']");
    }

    @Test
    public demo_isVisibleInViewport(){
        // you can build all kinds of abstractions on top of the base method
        // to make it more Selenium-ish using retries with timeouts, etc
        assertTrue(isVisibleInViewport("//button[@id='should_be_visible']"));
        assertFalse(isVisibleInViewport("//button[@id='should_be_hidden']"));
    }
}

How to determine the version of the C++ standard used by the compiler?

Use __cplusplus as suggested. Only one note for Microsoft compiler, use Zc:__cplusplus compiler switch to enable __cplusplus

Source https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/

How to read XML response from a URL in java?

I found that the above answer caused me an exception when I tried to instantiate the parser. I found the following code that resolved this at http://docstore.mik.ua/orelly/xml/sax2/ch03_02.htm.

import org.xml.sax.*;
import javax.xml.parsers.*;

XMLReader        parser;

try {
    SAXParserFactory factory;

    factory = SAXParserFactory.newInstance ();
    factory.setNamespaceAware (true);
    parser = factory.newSAXParser ().getXMLReader ();
    // success!

} catch (FactoryConfigurationError err) {
    System.err.println ("can't create JAXP SAXParserFactory, "
    + err.getMessage ());
} catch (ParserConfigurationException err) {
    System.err.println ("can't create XMLReader with namespaces, "
    + err.getMessage ());
} catch (SAXException err) {
    System.err.println ("Hmm, SAXException, " + err.getMessage ());
}

How to add a string to a string[] array? There's no .Add function

You can't add items to an array, since it has fixed length. What you're looking for is a List<string>, which can later be turned to an array using list.ToArray(), e.g.

List<string> list = new List<string>();
list.Add("Hi");
String[] str = list.ToArray();

How to find reason of failed Build without any error or warning

Since everything did not work, found that errors don't show when opening the project as solution (.sln), while the error shows when opening the project as a project.