Programs & Examples On #Template inheritance

JSP tricks to make templating easier?

I know this answer is coming years after the fact and there is already a great JSP answer by Will Hartung, but there is Facelets, they are even mentioned in the answers from the linked question in the original question.

Facelets SO tag description

Facelets is an XML-based view technology for the JavaServer Faces framework. Designed specifically for JSF, Facelets is intended to be a simpler and more powerful alternative to JSP-based views. Initially a separate project, the technology was standardized as part of JSF 2.0 and Java-EE 6 and has deprecated JSP. Almost all JSF 2.0 targeted component libraries do not support JSP anymore, but only Facelets.

Sadly the best plain tutorial description I found was on Wikipedia and not a tutorial site. In fact the section describing templates even does along the lines of what the original question was asking for.

Due to the fact that Java-EE 6 has deprecated JSP I would recommend going with Facelets despite the fact that it looks like there might be more required for little to no gain over JSP.

PowerShell: Create Local User Account

Import-Csv C:\test.csv |
Foreach-Object {
  NET USER    $ _.username   $ _.password /ADD
  NET LOCALGROUP "group" $_.username  /ADD
}

edit csv as username,password and change "group" for your groupname

:) worked on 2012 R2

WPF Databinding: How do I access the "parent" data context?

This will also work:

<Hyperlink Command="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl},
                             Path=DataContext.AllowItemCommand}" />

ListView will inherit its DataContext from Window, so it's available at this point, too.
And since ListView, just like similar controls (e. g. Gridview, ListBox, etc.), is a subclass of ItemsControl, the Binding for such controls will work perfectly.

Convert boolean result into number/integer

You can also add 0, use shift operators or xor:

val + 0;
val ^ 0;
val >> 0;
val >>> 0;
val << 0;

These have similar speeds as those from the others answers.

How to run multiple Python versions on Windows

Using a batch file to switch, easy and efficient on windows 7. I use this:

In the environment variable dialog (C:\Windows\System32\SystemPropertiesAdvanced.exe),

In the section user variables

  1. added %pathpython% to the path environment variable

  2. removed any references to python pathes

In the section system variables

  1. removed any references to python pathes

I created batch files for every python installation (exmple for 3.4 x64

Name = SetPathPython34x64 !!! ToExecuteAsAdmin.bat ;-) just to remember.

Content of the file =

     Set PathPython=C:\Python36AMD64\Scripts\;C:\Python36AMD64\;C:\Tcl\bin

     setx PathPython %PathPython%

To switch between versions, I execute the batch file in admin mode.

!!!!! The changes are effective for the SUBSEQUENT command prompt windows OPENED. !!!

So I have exact control on it.

TypeError: 'str' object is not callable (Python)

In my case I had a class that had a method and a string property of the same name, I was trying to call the method but was getting the string property.

The requested URL /about was not found on this server

FWIW: I rebuilt a LAMP server from scratch and installed WordPress. I had the same issue after saving my Permalink setting to generate the .htaccess file. Turns out that mod_rewrite was not enabled. I ran across this post on Digital Ocean.
FTA:

First, we need to activate mod_rewrite. It’s available but not enabled with a clean Apache 2 installation.

$ sudo a2enmod rewrite

This will activate the module or alert you that the module is already enabled. To put these changes into effect, restart Apache.

$ sudo systemctl restart apache2

Query for array elements inside JSON type

Create a table with column as type json

CREATE TABLE friends ( id serial primary key, data jsonb);

Now let's insert json data

INSERT INTO friends(data) VALUES ('{"name": "Arya", "work": ["Improvements", "Office"], "available": true}');
INSERT INTO friends(data) VALUES ('{"name": "Tim Cook", "work": ["Cook", "ceo", "Play"], "uses": ["baseball", "laptop"], "available": false}');

Now let's make some queries to fetch data

select data->'name' from friends;
select data->'name' as name, data->'work' as work from friends;

You might have noticed that the results comes with inverted comma( " ) and brackets ([ ])

    name    |            work            
------------+----------------------------
 "Arya"     | ["Improvements", "Office"]
 "Tim Cook" | ["Cook", "ceo", "Play"]
(2 rows)

Now to retrieve only the values just use ->>

select data->>'name' as name, data->'work'->>0 as work from friends;
select data->>'name' as name, data->'work'->>0 as work from friends where data->>'name'='Arya';

SQL Server String or binary data would be truncated

One other potential reason for this is if you have a default value setup for a column that exceeds the length of the column. It appears someone fat fingered a column that had a length of 5 but the default value exceeded the length of 5. This drove me nuts as I was trying to understand why it wasn't working on any insert, even if all i was inserting was a single column with an integer of 1. Because the default value on the table schema had that violating default value it messed it all up - which I guess brings us to the lesson learned - avoid having tables with default value's in the schema. :)

C# Enum - How to Compare Value

You can use extension methods to do the same thing with less code.

public enum AccountType
{
    Retailer = 1,
    Customer = 2,
    Manager = 3,
    Employee = 4
}

static class AccountTypeMethods
{
    public static bool IsRetailer(this AccountType ac)
    {
        return ac == AccountType.Retailer;
    }
}

And to use:

if (userProfile.AccountType.isRetailer())
{
    //your code
}

I would recommend to rename the AccountType to Account. It's not a name convention.

In Javascript/jQuery what does (e) mean?

e is the short var reference for event object which will be passed to event handlers.

The event object essentially has lot of interesting methods and properties that can be used in the event handlers.

In the example you have posted is a click handler which is a MouseEvent

$(<element selector>).click(function(e) {
    // does something
    alert(e.type); //will return you click
}

DEMO - Mouse Events DEMO uses e.which and e.type

Some useful references:

http://api.jquery.com/category/events/

http://www.quirksmode.org/js/events_properties.html

http://www.javascriptkit.com/jsref/event.shtml

http://www.quirksmode.org/dom/events/index.html

http://www.w3.org/TR/DOM-Level-3-Events/#event-types-list

Warning: Each child in an array or iterator should have a unique "key" prop. Check the render method of `ListView`

I've had exactly the same problem as you for a while now, and after looking at some of the suggestions above, I finally solved the problem.

It turns out (at least for me anyway), I needed to supply a key (a prop called 'key') to the component I am returning from my renderSeparator method. Adding a key to my renderRow or renderSectionHeader didn't do anything, but adding it to renderSeparator made the warning go away.

Hope that helps.

Post form data using HttpWebRequest

Use this code:

internal void SomeFunction() {
    Dictionary<string, string> formField = new Dictionary<string, string>();
    
    formField.Add("Name", "Henry");
    formField.Add("Age", "21");
    
    string body = GetBodyStringFromDictionary(formField);
    // output : Name=Henry&Age=21
}

internal string GetBodyStringFromDictionary(Dictionary<string, string> formField)
{
    string body = string.Empty;
    foreach (var pair in formField)
    {
        body += $"{pair.Key}={pair.Value}&";   
    }

    // delete last "&"
    body = body.Substring(0, body.Length - 1);

    return body;
}

Two statements next to curly brace in an equation

That can be achieve in plain LaTeX without any specific package.

\documentclass{article}
\begin{document}
This is your only binary choices
\begin{math}
  \left\{
    \begin{array}{l}
      0\\
      1
    \end{array}
  \right.
\end{math}
\end{document}

This code produces something which looks what you seems to need.

curly braces in front of two lines

The same example as in the @Tombart can be obtained with similar code.

\documentclass{article}

\begin{document}

\begin{math}
  f(x)=\left\{
    \begin{array}{ll}
      1, & \mbox{if $x<0$}.\\
      0, & \mbox{otherwise}.
    \end{array}
  \right.
\end{math}

\end{document}

This code produces very similar results.

enter image description here

Export JAR with Netbeans

It does this by default, you just need to look into the project's /dist folder.

Map to String in Java

You can also use google-collections (guava) Joiner class if you want to customize the print format

Jquery check if element is visible in viewport

var visible = $(".media").visible();

How to save the contents of a div as a image?

Do something like this:

A <div> with ID of #imageDIV, another one with ID #download and a hidden <div> with ID #previewImage.

Include the latest version of jquery, and jspdf.debug.js from the jspdf CDN

Then add this script:

var element = $("#imageDIV"); // global variable
var getCanvas; // global variable
$('document').ready(function(){
  html2canvas(element, {
    onrendered: function (canvas) {
      $("#previewImage").append(canvas);
      getCanvas = canvas;
    }
  });
});
$("#download").on('click', function () {
  var imgageData = getCanvas.toDataURL("image/png");
  // Now browser starts downloading it instead of just showing it
  var newData = imageData.replace(/^data:image\/png/, "data:application/octet-stream");
  $("#download").attr("download", "image.png").attr("href", newData);
});

The div will be saved as a PNG on clicking the #download

How to access a dictionary element in a Django template?

You could use a namedtuple instead of a dict. This is a shorthand for using a data class. Instead of

person = {'name':  'John', 'age':  14}

...do:

from collections import namedtuple
Person = namedtuple('person', ['name', 'age'])
p = Person(name='John', age=14)
p.name # 'John'

This is the same as writing a class that just holds data. In general I would avoid using dicts in django templates because they are awkward.

Launch an app on OS X with command line

In OS X 10.6, the open command was enhanced to allow passing of arguments to the application:

open ./AppName.app --args -AppCommandLineArg

But for older versions of Mac OS X, and because app bundles aren't designed to be passed command line arguments, the conventional mechanism is to use Apple Events for files like here for Cocoa apps or here for Carbon apps. You could also probably do something kludgey by passing parameters in using environment variables.

Adding a css class to select using @Html.DropDownList()

Try This

 @Html.DropDownList("Id", null, new { @class = "ct-js-select ct-select-lg" })

UILabel is not auto-shrinking text to fit label size

Here's how to do it.Suppose the following messageLabel is the label you want to have the desired effect.Now,try these simple line of codes:

    //SET THE WIDTH CONSTRAINTS FOR LABEL.
    CGFloat constrainedWidth = 240.0f;//YOU CAN PUT YOUR DESIRED ONE,THE MAXIMUM WIDTH OF YOUR LABEL.
 //CALCULATE THE SPACE FOR THE TEXT SPECIFIED.
    CGSize sizeOfText=[yourText sizeWithFont:yourFont constrainedToSize:CGSizeMake(constrainedWidth, CGFLOAT_MAX) lineBreakMode:UILineBreakModeWordWrap];
    UILabel *messageLabel=[[UILabel alloc] initWithFrame:CGRectMake(20,20,constrainedWidth,sizeOfText.height)];
    messageLabel.text=yourText;
    messageLabel.numberOfLines=0;//JUST TO SUPPORT MULTILINING.

One line if statement not working

if else condition can be covered with ternary operator

@item.rigged? ? 'Yes' : 'No'

How to calculate the inverse of the normal cumulative distribution function in python?

Starting Python 3.8, the standard library provides the NormalDist object as part of the statistics module.

It can be used to get the inverse cumulative distribution function (inv_cdf - inverse of the cdf), also known as the quantile function or the percent-point function for a given mean (mu) and standard deviation (sigma):

from statistics import NormalDist

NormalDist(mu=10, sigma=2).inv_cdf(0.95)
# 13.289707253902943

Which can be simplified for the standard normal distribution (mu = 0 and sigma = 1):

NormalDist().inv_cdf(0.95)
# 1.6448536269514715

UIWebView open links in Safari

Add this to the UIWebView delegate:

(edited to check for navigation type. you could also pass through file:// requests which would be relative links)

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
    if (navigationType == UIWebViewNavigationTypeLinkClicked ) {
        [[UIApplication sharedApplication] openURL:[request URL]];
        return NO;
    }

    return YES;
}

Swift Version:

func webView(webView: UIWebView, shouldStartLoadWithRequest request: NSURLRequest, navigationType: UIWebViewNavigationType) -> Bool {
        if navigationType == UIWebViewNavigationType.LinkClicked {
            UIApplication.sharedApplication().openURL(request.URL!)
            return false
        }
        return true
    }

Swift 3 version:

func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
    if navigationType == UIWebViewNavigationType.linkClicked {
        UIApplication.shared.openURL(request.url!)
        return false
    }
    return true
}

Swift 4 version:

func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebView.NavigationType) -> Bool {
    guard let url = request.url, navigationType == .linkClicked else { return true }
    UIApplication.shared.open(url, options: [:], completionHandler: nil)
    return false
}

Update

As openURL has been deprecated in iOS 10:

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
        if (navigationType == UIWebViewNavigationTypeLinkClicked ) {
            UIApplication *application = [UIApplication sharedApplication];
            [application openURL:[request URL] options:@{} completionHandler:nil];
            return NO;
        }

        return YES;
}

Format the date using Ruby on Rails

Here's my go at answering this,

so first you will need to convert the timestamp to an actual Ruby Date/Time. If you receive it just as a string or int from facebook, you will need to do something like this:

my_date = Time.at(timestamp_from_facebook.to_i)

OK, so now assuming you already have your date object...

to_formatted_s is a handy Ruby function that turns dates into formatted strings.

Here are some examples of its usage:

time = Time.now                     # => Thu Jan 18 06:10:17 CST 2007    

time.to_formatted_s(:time)          # => "06:10"
time.to_s(:time)                    # => "06:10"    

time.to_formatted_s(:db)            # => "2007-01-18 06:10:17"
time.to_formatted_s(:number)        # => "20070118061017"
time.to_formatted_s(:short)         # => "18 Jan 06:10"
time.to_formatted_s(:long)          # => "January 18, 2007 06:10"
time.to_formatted_s(:long_ordinal)  # => "January 18th, 2007 06:10"
time.to_formatted_s(:rfc822)        # => "Thu, 18 Jan 2007 06:10:17 -0600"

As you can see: :db, :number, :short ... are custom date formats.

To add your own custom format, you can create this file: config/initializers/time_formats.rb and add your own formats there, for example here's one:

Date::DATE_FORMATS[:month_day_comma_year] = "%B %e, %Y" # January 28, 2015

Where :month_day_comma_year is your format's name (you can change this to anything you want), and where %B %e, %Y is unix date format.

Here's a quick cheatsheet on unix date syntax, so you can quickly setup your custom format:

From http://linux.die.net/man/3/strftime    

  %a - The abbreviated weekday name (``Sun'')
  %A - The  full  weekday  name (``Sunday'')
  %b - The abbreviated month name (``Jan'')
  %B - The  full  month  name (``January'')
  %c - The preferred local date and time representation
  %d - Day of the month (01..31)
  %e - Day of the month without leading 0 (1..31) 
  %g - Year in YY (00-99)
  %H - Hour of the day, 24-hour clock (00..23)
  %I - Hour of the day, 12-hour clock (01..12)
  %j - Day of the year (001..366)
  %m - Month of the year (01..12)
  %M - Minute of the hour (00..59)
  %p - Meridian indicator (``AM''  or  ``PM'')
  %S - Second of the minute (00..60)
  %U - Week  number  of the current year,
          starting with the first Sunday as the first
          day of the first week (00..53)
  %W - Week  number  of the current year,
          starting with the first Monday as the first
          day of the first week (00..53)
  %w - Day of the week (Sunday is 0, 0..6)
  %x - Preferred representation for the date alone, no time
  %X - Preferred representation for the time alone, no date
  %y - Year without a century (00..99)
  %Y - Year with century
  %Z - Time zone name
  %% - Literal ``%'' character    

   t = Time.now
   t.strftime("Printed on %m/%d/%Y")   #=> "Printed on 04/09/2003"
   t.strftime("at %I:%M%p")            #=> "at 08:56AM"

Hope this helped you. I've also made a github gist of this little guide, in case anyone prefers.

How do I import a .bak file into Microsoft SQL Server 2012?

.bak is a backup file generated in SQL Server.

Backup files importing means restoring a database, you can restore on a database created in SQL Server 2012 but the backup file should be from SQL Server 2005, 2008, 2008 R2, 2012 database.

You restore database by using following command...

RESTORE DATABASE YourDB FROM DISK = 'D:BackUpYourBaackUpFile.bak' WITH Recovery

You want to learn about how to restore .bak file follow the below link:

http://msdn.microsoft.com/en-us/library/ms186858(v=sql.90).aspx

how to open a url in python

I think this is the easy way to open a URL using this function

webbrowser.open_new_tab(url)

How to solve time out in phpmyadmin?

If any of you happen to use WAMP then at least in the current version (3.0.6 x64) there's a file located in <your-wamp-dir>\alias\phpmyadmin.conf which overrides some of your php.ini options.

Edit this part:

# To import big file you can increase values php_admin_value upload_max_filesize 512M php_admin_value post_max_size 512M php_admin_value max_execution_time 600 php_admin_value max_input_time 600

Angular ng-if="" with multiple arguments

Just to clarify, be aware bracket placement is important!

These can be added to any HTML tags... span, div, table, p, tr, td etc.

AngularJS

ng-if="check1 && !check2" -- AND NOT
ng-if="check1 || check2" -- OR
ng-if="(check1 || check2) && check3" -- AND/OR - Make sure to use brackets

Angular2+

*ngIf="check1 && !check2" -- AND NOT
*ngIf="check1 || check2" -- OR
*ngIf="(check1 || check2) && check3" -- AND/OR - Make sure to use brackets

It's best practice not to do calculations directly within ngIfs, so assign the variables within your component, and do any logic there.

boolean check1 = Your conditional check here...
...

Print "\n" or newline characters as part of the output on terminal

If you're in control of the string, you could also use a 'Raw' string type:

>>> string = r"abcd\n"
>>> print(string)
abcd\n

Convert double/float to string

Use this:

void double_to_char(double f,char * buffer){
    gcvt(f,10,buffer);
}

Java FileWriter how to write to next Line

I'm not sure if I understood correctly, but is this what you mean?

out.write("this is line 1");
out.newLine();
out.write("this is line 2");
out.newLine();
...

PHP: Get key from array?

$foo = array('a' => 'apple', 'b' => 'ball', 'c' => 'coke');

foreach($foo as $key => $item) {
  echo $item.' is begin with ('.$key.')';
}

correct way to use super (argument passing)

Sometimes two classes may have some parameter names in common. In that case, you can't pop the key-value pairs off of **kwargs or remove them from *args. Instead, you can define a Base class which unlike object, absorbs/ignores arguments:

class Base(object):
    def __init__(self, *args, **kwargs): pass

class A(Base):
    def __init__(self, *args, **kwargs):
        print "A"
        super(A, self).__init__(*args, **kwargs)

class B(Base):
    def __init__(self, *args, **kwargs):
        print "B"
        super(B, self).__init__(*args, **kwargs)

class C(A):
    def __init__(self, arg, *args, **kwargs):
        print "C","arg=",arg
        super(C, self).__init__(arg, *args, **kwargs)

class D(B):
    def __init__(self, arg, *args, **kwargs):
        print "D", "arg=",arg
        super(D, self).__init__(arg, *args, **kwargs)

class E(C,D):
    def __init__(self, arg, *args, **kwargs):
        print "E", "arg=",arg
        super(E, self).__init__(arg, *args, **kwargs)

print "MRO:", [x.__name__ for x in E.__mro__]
E(10)

yields

MRO: ['E', 'C', 'A', 'D', 'B', 'Base', 'object']
E arg= 10
C arg= 10
A
D arg= 10
B

Note that for this to work, Base must be the penultimate class in the MRO.

How can I define an array of objects?

What you really want may simply be an enumeration

If you're looking for something that behaves like an enumeration (because I see you are defining an object and attaching a sequential ID 0, 1, 2 and contains a name field that you don't want to misspell (e.g. name vs naaame), you're better off defining an enumeration because the sequential ID is taken care of automatically, and provides type verification for you out of the box.

enum TestStatus {
    Available,     // 0
    Ready,         // 1
    Started,       // 2
}

class Test {
    status: TestStatus
}

var test = new Test();
test.status = TestStatus.Available; // type and spelling is checked for you,
                                    // and the sequence ID is automatic

The values above will be automatically mapped, e.g. "0" for "Available", and you can access them using TestStatus.Available. And Typescript will enforce the type when you pass those around.

If you insist on defining a new type as an array of your custom type

You wanted an array of objects, (not exactly an object with keys "0", "1" and "2"), so let's define the type of the object, first, then a type of a containing array.

class TestStatus {
    id: number
    name: string

    constructor(id, name){
        this.id = id;
        this.name = name;
    }
}

type Statuses = Array<TestStatus>;

var statuses: Statuses = [
    new TestStatus(0, "Available"),
    new TestStatus(1, "Ready"),
    new TestStatus(2, "Started")
]

Proper way to use **kwargs in Python

You could do something like this

class ExampleClass:
    def __init__(self, **kwargs):
        arguments = {'val':1, 'val2':2}
        arguments.update(kwargs)
        self.val = arguments['val']
        self.val2 = arguments['val2']

Disabling right click on images using jquery

This works:

$('img').bind('contextmenu', function(e) {
    return false;
}); 

Or for newer jQuery:

$('#nearestStaticContainer').on('contextmenu', 'img', function(e){ 
  return false; 
});

jsFiddle example

Adding 30 minutes to time formatted as H:i in PHP

I usually take a slightly different track to achieve this:

$startTime = date("H:i",time() - 1800);
$endTime = date("H:i",time() + 1800);

Where 1800 seconds = 30 minutes.

Does Java SE 8 have Pairs or Tuples?

Vavr (formerly called Javaslang) (http://www.vavr.io) provides tuples (til size of 8) as well. Here is the javadoc: https://static.javadoc.io/io.vavr/vavr/0.9.0/io/vavr/Tuple.html.

This is a simple example:

Tuple2<Integer, String> entry = Tuple.of(1, "A");

Integer key = entry._1;
String value = entry._2;

Why JDK itself did not come with a simple kind of tuples til now is a mystery to me. Writing wrapper classes seems to be an every day business.

Remove multiple items from a Python list in just one statement

You can do it in one line by converting your lists to sets and using set.difference:

item_list = ['item', 5, 'foo', 3.14, True]
list_to_remove = ['item', 5, 'foo']

final_list = list(set(item_list) - set(list_to_remove))

Would give you the following output:

final_list = [3.14, True]

Note: this will remove duplicates in your input list and the elements in the output can be in any order (because sets don't preserve order). It also requires all elements in both of your lists to be hashable.

Changing the default title of confirm() in JavaScript?

YES YOU CAN do it!! It's a little tricky way ; ) (it almost works on ios)

var iframe = document.createElement("IFRAME");
iframe.setAttribute("src", 'data:text/plain,');
document.documentElement.appendChild(iframe);
if(window.frames[0].window.confirm("Are you sure?")){
    // what to do if answer "YES"
}else{
    // what to do if answer "NO"
}

Enjoy it!

How to list files in a directory in a C program?

An example, available for POSIX compliant systems :

/*
 * This program displays the names of all files in the current directory.
 */

#include <dirent.h> 
#include <stdio.h> 

int main(void) {
  DIR *d;
  struct dirent *dir;
  d = opendir(".");
  if (d) {
    while ((dir = readdir(d)) != NULL) {
      printf("%s\n", dir->d_name);
    }
    closedir(d);
  }
  return(0);
}

Beware that such an operation is platform dependant in C.

Source : http://faq.cprogramming.com/cgi-bin/smartfaq.cgi?answer=1046380353&id=1044780608

No module named MySQLdb

Note this is not tested for python 3.x

In CMD

pip install wheel
pip install pymysql

in settings.py

import pymysql
pymysql.install_as_MySQLdb()

It worked with me

Android ListView headers

What I did to make the Date (e.g December 01, 2016) as header. I used the StickyHeaderListView library

https://github.com/emilsjolander/StickyListHeaders

Convert the date to long in millis [do not include the time] and make it as the header Id.

@Override
public long getHeaderId(int position) {
    return <date in millis>;
}

How to reload current page?

Here is the simple one

if (this.router && this.router.url === '/') { or your current page url e.g '/home' 
    window.location.reload();
  } else {
    this.router.navigate([url]);
  }

Limitations of SQL Server Express

Another limitation to consider is that SQL Server Express editions go into an idle mode after a period of disuse.

Understanding SQL Express behavior: Idle time resource usage, AUTO_CLOSE and User Instances:

When SQL Express is idle it aggressively trims back the working memory set by writing the cached data back to disk and releasing the memory.

But this is easily worked around: Is there a way to stop SQL Express 2008 from Idling?

XML shape drawable not rendering desired color

In drawable I use this xml code to define the border and background:

<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
  <stroke android:width="4dp" android:color="#D8FDFB" /> 
  <padding android:left="7dp" android:top="7dp" 
    android:right="7dp" android:bottom="7dp" /> 
  <corners android:radius="4dp" /> 
  <solid android:color="#f0600000"/> 
</shape> 

facebook Uncaught OAuthException: An active access token must be used to query information about the current user

I have got the same issue when tried to get users information without auth.

Check if you have loggen in before any request.

 $uid = $facebook->getUser();

 if ($uid){
      $me = $facebook->api('/me');
 }

The code above should solve your issue.

changing default x range in histogram matplotlib

plt.hist(hmag, 30, range=[6.5, 12.5], facecolor='gray', align='mid')

How to compile and run C in sublime text 3?

{
 "cmd": ["gcc", "-Wall", "-ansi", "-pedantic-errors", "$file_name", "-o", 
 "${file_base_name}.exe", "&&", "start", "cmd", "/k" , "$file_base_name"],
 "selector": "source.c",
 "working_dir": "${file_path}",
 "shell": true
}

It takes input and show output on a command prompt.

Escape double quote character in XML

Others have answered in terms of how to handle the specific escaping in this case.

A broader answer is not to try to do it yourself. Use an XML API - there are plenty available for just about every modern programming platform in existence.

XML APIs will handle things like this for you automatically, making it a lot harder to go wrong. Unless you're writing an XML API yourself, you should rarely need to worry about the details like this.

Git merge reports "Already up-to-date" though there is a difference

This often happens to me when I know there are changes on the remote master, so I try to merge them using git merge master. However, this doesn't merge with the remote master, but with your local master.

So before doing the merge, checkout master, and then git pull there. Then you will be able to merge the new changes into your branch.

xsl: how to split strings?

If your XSLT processor supports EXSLT, you can use str:tokenize, otherwise, the link contains an implementation using functions like substring-before.

The program can’t start because MSVCR71.dll is missing from your computer. Try reinstalling the program to fix this program

Here is the solution I found:

How to fix the missing MSVCR711.dll problem

You can find MSVCR71.dll file in following location of your installed SQL Developer 2.1 directory:

sqldeveloper-2.1.0.63.10\sqldeveloper\jdk\jre\bin\MSVCR71.dll

What does collation mean?

Rules that tell how to compare and sort strings: letters order; whether case matters, whether diacritics matter etc.

For instance, if you want all letters to be different (say, if you store filenames in UNIX), you use UTF8_BIN collation:

SELECT  'A' COLLATE UTF8_BIN = 'a' COLLATE UTF8_BIN

---
0

If you want to ignore case and diacritics differences (say, for a search engine), you use UTF8_GENERAL_CI collation:

SELECT  'A' COLLATE UTF8_GENERAL_CI = 'ä' COLLATE UTF8_GENERAL_CI

---
1

As you can see, this collation (comparison rule) considers capital A and lowecase ä the same letter, ignoring case and diacritic differences.

Eclipse Optimize Imports to Include Static Imports

From Content assist for static imports

To get content assist proposals for static members configure your list of favorite static members on the Opens the Favorites preference page Java > Editor > Content Assist > Favorites preference page.
For example, if you have added java.util.Arrays.* or org.junit.Assert.* to this list, then all static methods of this type matching the completion prefix will be added to the proposals list.

Open Window » Preferences » Java » Editor » Content Assist » Favorites

enter image description here

How can you program if you're blind?

I can't recall the source, but I've heard/read about a form of audible syntax "colouring" - so that instead of a string assignment being read as

foo equals quote this is a string quote

the string part would be read with a different pitch or voice to make the separation of elements clearer.

Replace multiple characters in one replace call

If you want to replace multiple characters you can call the String.prototype.replace() with the replacement argument being a function that gets called for each match. All you need is an object representing the character mapping which you will use in that function.

For example, if you want a replaced with x, b with y and c with z, you can do something like this:

var chars = {'a':'x','b':'y','c':'z'};
var s = '234abc567bbbbac';
s = s.replace(/[abc]/g, m => chars[m]);
console.log(s);

Output: 234xyz567yyyyxz

regex string replace

Your character class (the part in the square brackets) is saying that you want to match anything except 0-9 and a-z and +. You aren't explicit about how many a-z or 0-9 you want to match, but I assume the + means you want to replace strings of at least one alphanumeric character. It should read instead:

str = str.replace(/[^-a-z0-9]+/g, "");

Also, if you need to match upper-case letters along with lower case, you should use:

str = str.replace(/[^-a-zA-Z0-9]+/g, "");

Composer killed while updating

Increase the memory limit for composer

php -d memory_limit=4G /usr/local/bin/composer update

Defining a percentage width for a LinearLayout?

You have to set the weight property of your elements. Create three RelativeLayouts as children to your LinearLayout and set weights 0.15, 0.70, 0.15. Then add your buttons to the second RelativeLayout(the one with weight 0.70).

Like this:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:id="@+id/layoutContainer" android:orientation="horizontal">
    <RelativeLayout
        android:layout_width="0dip"
        android:layout_height="fill_parent"
        android:layout_weight="0.15">
    </RelativeLayout>
    <RelativeLayout
        android:layout_width="0dip"
        android:layout_height="fill_parent"
        android:layout_weight="0.7">
        
        <!-- This is the part that's 70% of the total width. I'm inserting a LinearLayout and buttons.-->   
            <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:orientation="vertical">
                
                <Button 
                    android:text="Button1"
                    android:layout_width="fill_parent"
                    android:layout_height="wrap_content">
                </Button>
                <Button
                    android:text="Button2"
                    android:layout_width="fill_parent"
                    android:layout_height="wrap_content">
                </Button>
                <Button
                    android:text="Button3"
                    android:layout_width="fill_parent"
                    android:layout_height="wrap_content">
                </Button>
                
            </LinearLayout>
        <!-- 70% Width End-->
        
    </RelativeLayout>
    <RelativeLayout
        android:layout_width="0dip"
        android:layout_height="fill_parent"
        android:layout_weight="0.15">
    </RelativeLayout>
</LinearLayout>

Why are the weights 0.15, 0.7 and 0.15? Because the total weight is 1 and 0.7 is 70% of the total.

Result:

enter image description here

Edit: Thanks to @SimonVeloper for pointing out that the orientation should be horizontal and not vertical and to @Andrew for pointing out that weights can be decimals instead of integers.

ImportError in importing from sklearn: cannot import name check_build

i had the same problem reinstalling anaconda solved the issue for me

Is there a way to access an iteration-counter in Java's for-each loop?

Java 8 introduced the Iterable#forEach() / Map#forEach() method, which is more efficient for many Collection / Map implementations compared to the "classical" for-each loop. However, also in this case an index is not provided. The trick here is to use AtomicInteger outside the lambda expression. Note: variables used within the lambda expression must be effectively final, that is why we cannot use an ordinary int.

final AtomicInteger indexHolder = new AtomicInteger();
map.forEach((k, v) -> {
    final int index = indexHolder.getAndIncrement();
    // use the index
});

What does "atomic" mean in programming?

"Atomic operation" means an operation that appears to be instantaneous from the perspective of all other threads. You don't need to worry about a partly complete operation when the guarantee applies.

Get mouse wheel events in jQuery?

Here is a vanilla solution. Can be used in jQuery if the event passed to the function is event.originalEvent which jQuery makes available as property of the jQuery event. Or if inside the callback function under we add before first line: event = event.originalEvent;.

This code normalizes the wheel speed/amount and is positive for what would be a forward scroll in a typical mouse, and negative in a backward mouse wheel movement.

Demo: http://jsfiddle.net/BXhzD/

var wheel = document.getElementById('wheel');

function report(ammout) {
    wheel.innerHTML = 'wheel ammout: ' + ammout;
}

function callback(event) {
    var normalized;
    if (event.wheelDelta) {
        normalized = (event.wheelDelta % 120 - 0) == -0 ? event.wheelDelta / 120 : event.wheelDelta / 12;
    } else {
        var rawAmmount = event.deltaY ? event.deltaY : event.detail;
        normalized = -(rawAmmount % 3 ? rawAmmount * 10 : rawAmmount / 3);
    }
    report(normalized);
}

var event = 'onwheel' in document ? 'wheel' : 'onmousewheel' in document ? 'mousewheel' : 'DOMMouseScroll';
window.addEventListener(event, callback);

There is also a plugin for jQuery, which is more verbose in the code and some extra sugar: https://github.com/brandonaaron/jquery-mousewheel

Locking a file in Python

Alright, so I ended up going with the code I wrote here, on my website link is dead, view on archive.org (also available on GitHub). I can use it in the following fashion:

from filelock import FileLock

with FileLock("myfile.txt.lock"):
    print("Lock acquired.")
    with open("myfile.txt"):
        # work with the file as it is now locked

Force browser to refresh css, javascript, etc

Try this:

link href="styles/style.css?=time()" rel="stylesheet" type="text/css"

If you need something after the '?' that is different every time the page is accessed then the time() will do it. Leaving this in your code permanently is not really a good idea since it will only slow down page loading and probably isn't necessary.

I've found that forcing a style sheet refresh is helpful if you've made extensive changes to a page's layout and accessing the new style sheet is vital to having something sensible appear on the screen.

u'\ufeff' in Python string

That character is the BOM or "Byte Order Mark". It is usually received as the first few bytes of a file, telling you how to interpret the encoding of the rest of the data. You can simply remove the character to continue. Although, since the error says you were trying to convert to 'ascii', you should probably pick another encoding for whatever you were trying to do.

Setting Windows PowerShell environment variables

If, some time during a PowerShell session, you need to append to the PATH environment variable temporarily, you can do it this way:

$env:Path += ";C:\Program Files\GnuWin32\bin"

Highlight all occurrence of a selected word?

to highlight word without moving cursor, plop

" highlight reg. ex. in @/ register
set hlsearch
" remap `*`/`#` to search forwards/backwards (resp.)
" w/o moving cursor
nnoremap <silent> * :execute "normal! *N"<cr>
nnoremap <silent> # :execute "normal! #n"<cr>

into your vimrc.

What's nice about this is g* and g# will still work like "normal" * and #.


To set hlsearch off, you can use "short-form" (unless you have another function that starts with "noh" in command mode): :noh. Or you can use long version: :nohlsearch

For extreme convenience (I find myself toggling hlsearch maybe 20 times per day), you can map something to toggle hlsearch like so:

" search highlight toggle
nnoremap <silent> <leader>st :set hlsearch!<cr>

.:. if your <leader> is \ (it is by default), you can press \st (quickly) in normal mode to toggle hlsearch.

Or maybe you just want to have :noh mapped:

" search clear
nnoremap <silent> <leader>sc :nohlsearch<cr>

The above simply runs :nohlsearch so (unlike :set hlsearch!) it will still highlight word next time you press * or # in normal mode.

cheers

How can I selectively escape percent (%) in Python strings?

I have tried different methods to print a subplot title, look how they work. It's different when i use Latex.

It works with '%%' and 'string'+'%' in a typical case.

If you use Latex it worked using 'string'+'\%'

So in a typical case:

import matplotlib.pyplot as plt
fig,ax = plt.subplots(4,1)
float_number = 4.17
ax[0].set_title('Total: (%1.2f' %float_number + '\%)')
ax[1].set_title('Total: (%1.2f%%)' %float_number)
ax[2].set_title('Total: (%1.2f' %float_number + '%%)')
ax[3].set_title('Total: (%1.2f' %float_number + '%)')

Title examples with %

If we use latex:

import matplotlib.pyplot as plt
import matplotlib
font = {'family' : 'normal',
        'weight' : 'bold',
        'size'   : 12}
matplotlib.rc('font', **font)
matplotlib.rcParams['text.usetex'] = True
matplotlib.rcParams['text.latex.unicode'] = True
fig,ax = plt.subplots(4,1)
float_number = 4.17
#ax[0].set_title('Total: (%1.2f\%)' %float_number) This makes python crash
ax[1].set_title('Total: (%1.2f%%)' %float_number)
ax[2].set_title('Total: (%1.2f' %float_number + '%%)')
ax[3].set_title('Total: (%1.2f' %float_number + '\%)')

We get this: Title example with % and latex

How to read an entire file to a string using C#?

System.IO.StreamReader myFile =
   new System.IO.StreamReader("c:\\test.txt");
string myString = myFile.ReadToEnd();

How to add a "open git-bash here..." context menu to the windows explorer?

What worked for me was almost this, but with the following REGEDIT path:
HKEY_LOCAL_MACHINE/SOFTWARE/Classes/Directory/background/shell and here I created the key Bash, with the value of what I want the display name to be, and then created another key under this named command with the value as the path to git-bash.exe

I'm on Windows 10 and have a fresh git install that didn't add this automatically for some reason (git version 2.12.0 64bit)

How to close a JavaFX application on window close?

Some of the provided answers did not work for me (javaw.exe still running after closing the window) or, eclipse showed an exception after the application was closed.

On the other hand, this works perfectly:

primaryStage.setOnCloseRequest(new EventHandler<WindowEvent>() {
    @Override
    public void handle(WindowEvent t) {
        Platform.exit();
        System.exit(0);
    }
});

'mvn' is not recognized as an internal or external command,

On my Windows 7 machine I have the following environment variables:

  • JAVA_HOME=C:\Program Files\Java\jdk1.7.0_07

  • M2_HOME=C:\apache-maven-3.0.3

On my PATH variable, I have (among others) the following:

  • %JAVA_HOME%\bin;%M2_HOME%\bin

I tried doing what you've done with %M2% having the nested %M2_HOME% and it also works.

Request Monitoring in Chrome

Update

Chrome changed how to inspect requests and suggests now to use the Catapult Netlog Viewer with the logs exported from chrome://net-export/

chrome://net-export/

More Info

Old Chrome Versions

You also may use this link in Chrome for more detailed information than the inspector did it.

chrome://net-internals/#events

This shows the log of all requests of the browser while open

jquery: get value of custom attribute

You can also do this by passing function with onclick event

<a onclick="getColor(this);" color="red">

<script type="text/javascript">

function getColor(el)
{
     color = $(el).attr('color');
     alert(color);
}

</script> 

Why is my Git Submodule HEAD detached from master?

Check out my answer here: Git submodules: Specify a branch/tag

If you want, you can add the "branch = master" line into your .gitmodules file manually. Read the link to see what I mean.

EDIT: To track an existing submodule project at a branch, follow VonC's instructions here instead:

Git submodules: Specify a branch/tag

How to return result of a SELECT inside a function in PostgreSQL?

Use RETURN QUERY:

CREATE OR REPLACE FUNCTION word_frequency(_max_tokens int)
  RETURNS TABLE (txt   text   -- also visible as OUT parameter inside function
               , cnt   bigint
               , ratio bigint) AS
$func$
BEGIN
   RETURN QUERY
   SELECT t.txt
        , count(*) AS cnt                 -- column alias only visible inside
        , (count(*) * 100) / _max_tokens  -- I added brackets
   FROM  (
      SELECT t.txt
      FROM   token t
      WHERE  t.chartype = 'ALPHABETIC'
      LIMIT  _max_tokens
      ) t
   GROUP  BY t.txt
   ORDER  BY cnt DESC;                    -- potential ambiguity 
END
$func$  LANGUAGE plpgsql;

Call:

SELECT * FROM word_frequency(123);

Explanation:

  • It is much more practical to explicitly define the return type than simply declaring it as record. This way you don't have to provide a column definition list with every function call. RETURNS TABLE is one way to do that. There are others. Data types of OUT parameters have to match exactly what is returned by the query.

  • Choose names for OUT parameters carefully. They are visible in the function body almost anywhere. Table-qualify columns of the same name to avoid conflicts or unexpected results. I did that for all columns in my example.

    But note the potential naming conflict between the OUT parameter cnt and the column alias of the same name. In this particular case (RETURN QUERY SELECT ...) Postgres uses the column alias over the OUT parameter either way. This can be ambiguous in other contexts, though. There are various ways to avoid any confusion:

    1. Use the ordinal position of the item in the SELECT list: ORDER BY 2 DESC. Example:
    2. Repeat the expression ORDER BY count(*).
    3. (Not applicable here.) Set the configuration parameter plpgsql.variable_conflict or use the special command #variable_conflict error | use_variable | use_column in the function. See:
  • Don't use "text" or "count" as column names. Both are legal to use in Postgres, but "count" is a reserved word in standard SQL and a basic function name and "text" is a basic data type. Can lead to confusing errors. I use txt and cnt in my examples.

  • Added a missing ; and corrected a syntax error in the header. (_max_tokens int), not (int maxTokens) - type after name.

  • While working with integer division, it's better to multiply first and divide later, to minimize the rounding error. Even better: work with numeric (or a floating point type). See below.

Alternative

This is what I think your query should actually look like (calculating a relative share per token):

CREATE OR REPLACE FUNCTION word_frequency(_max_tokens int)
  RETURNS TABLE (txt            text
               , abs_cnt        bigint
               , relative_share numeric) AS
$func$
BEGIN
   RETURN QUERY
   SELECT t.txt, t.cnt
        , round((t.cnt * 100) / (sum(t.cnt) OVER ()), 2)  -- AS relative_share
   FROM  (
      SELECT t.txt, count(*) AS cnt
      FROM   token t
      WHERE  t.chartype = 'ALPHABETIC'
      GROUP  BY t.txt
      ORDER  BY cnt DESC
      LIMIT  _max_tokens
      ) t
   ORDER  BY t.cnt DESC;
END
$func$  LANGUAGE plpgsql;

The expression sum(t.cnt) OVER () is a window function. You could use a CTE instead of the subquery - pretty, but a subquery is typically cheaper in simple cases like this one.

A final explicit RETURN statement is not required (but allowed) when working with OUT parameters or RETURNS TABLE (which makes implicit use of OUT parameters).

round() with two parameters only works for numeric types. count() in the subquery produces a bigint result and a sum() over this bigint produces a numeric result, thus we deal with a numeric number automatically and everything just falls into place.

How do I install and use the ASP.NET AJAX Control Toolkit in my .NET 3.5 web applications?

You can easily install it by writing

Install-Package AjaxControlToolkit in package manager console.

for more information you can check this link

Use basic authentication with jQuery and Ajax

How things change in a year. In addition to the header attribute in place of xhr.setRequestHeader, current jQuery (1.7.2+) includes a username and password attribute with the $.ajax call.

$.ajax
({
  type: "GET",
  url: "index1.php",
  dataType: 'json',
  username: username,
  password: password,
  data: '{ "comment" }',
  success: function (){
    alert('Thanks for your comment!'); 
  }
});

EDIT from comments and other answers: To be clear - in order to preemptively send authentication without a 401 Unauthorized response, instead of setRequestHeader (pre -1.7) use 'headers':

$.ajax
({
  type: "GET",
  url: "index1.php",
  dataType: 'json',
  headers: {
    "Authorization": "Basic " + btoa(USERNAME + ":" + PASSWORD)
  },
  data: '{ "comment" }',
  success: function (){
    alert('Thanks for your comment!'); 
  }
});

Run CRON job everyday at specific time

From cron manual http://man7.org/linux/man-pages/man5/crontab.5.html:

Lists are allowed. A list is a set of numbers (or ranges) separated by commas. Examples: "1,2,5,9", "0-4,8-12".

So in this case it would be:

30 10,14 * * *

ls command: how can I get a recursive full-path listing, one line per file?

Run a bash command with the following format:

find /path -type f -exec ls -l \{\} \;

jQuery Ajax simple call

You could also make the ajax call more generic, reusable, so you can call it from different CRUD(create, read, update, delete) tasks for example and treat the success cases from those calls.

makePostCall = function (url, data) { // here the data and url are not hardcoded anymore
   var json_data = JSON.stringify(data);

    return $.ajax({
        type: "POST",
        url: url,
        data: json_data,
        dataType: "json",
        contentType: "application/json;charset=utf-8"
    });
}

// and here a call example
makePostCall("index.php?action=READUSERS", {'city' : 'Tokio'})
    .success(function(data){
               // treat the READUSERS data returned
   })
    .fail(function(sender, message, details){
           alert("Sorry, something went wrong!");
  });

How to set the min and max height or width of a Frame?

A workaround - at least for the minimum size: You can use grid to manage the frames contained in root and make them follow the grid size by setting sticky='nsew'. Then you can use root.grid_rowconfigure and root.grid_columnconfigure to set values for minsize like so:

from tkinter import Frame, Tk

class MyApp():
    def __init__(self):
        self.root = Tk()

        self.my_frame_red = Frame(self.root, bg='red')
        self.my_frame_red.grid(row=0, column=0, sticky='nsew')

        self.my_frame_blue = Frame(self.root, bg='blue')
        self.my_frame_blue.grid(row=0, column=1, sticky='nsew')

        self.root.grid_rowconfigure(0, minsize=200, weight=1)
        self.root.grid_columnconfigure(0, minsize=200, weight=1)
        self.root.grid_columnconfigure(1, weight=1)

        self.root.mainloop()

if __name__ == '__main__':
    app = MyApp()

But as Brian wrote (in 2010 :D) you can still resize the window to be smaller than the frame if you don't limit its minsize.

CSS position absolute full width problem

You need to add position:relative to #wrap element.

When you add this, all child elements will be positioned in this element, not browser window.

Multiline TextBox multiple newline

You need to set the textbox to be multiline, this can be done two ways:

In the control:

<asp:TextBox runat="server" ID="MyBox" TextMode="MultiLine" Rows="10" />

Code Behind:

MyBox.TextMode = TextBoxMode.MultiLine;
MyBox.Rows = 10;

This will render as a <textarea>

Find kth smallest element in a binary search tree in Optimum way

Best approach is already there.But I'd like to add a simple Code for that

int kthsmallest(treenode *q,int k){
int n = size(q->left) + 1;
if(n==k){
    return q->val;
}
if(n > k){
    return kthsmallest(q->left,k);
}
if(n < k){
    return kthsmallest(q->right,k - n);
}

}

int size(treenode *q){
if(q==NULL){
    return 0;
}
else{
    return ( size(q->left) + size(q->right) + 1 );
}}

Calculate percentage Javascript

You can use this

function percentage(partialValue, totalValue) {
   return (100 * partialValue) / totalValue;
} 

Example to calculate the percentage of a course progress base in their activities.

const totalActivities = 10;
const doneActivities = 2;

percentage(doneActivities, totalActivities) // Will return 20 that is 20%

Chrome/jQuery Uncaught RangeError: Maximum call stack size exceeded

This problem happened with me when I used jQUery Fancybox inside a website with many others jQuery plugins. When I used the LightBox (site here) instead of Fancybox, the problem is gone.

fs.writeFile in a promise, asynchronous-synchronous stuff

What worked for me was fs.promises.

Example One:

const fs = require("fs")

fs.promises
  .writeFile(__dirname + '/test.json', "data", { encoding: 'utf8' })
  .then(() => {
    // Do whatever you want to do.
    console.log('Done');
  });

Example Two. Using Async-Await:

const fs = require("fs")

async function writeToFile() {
  await fs.promises.writeFile(__dirname + '/test-22.json', "data", {
    encoding: 'utf8'
  });

  console.log("done")
}

writeToFile()

Datatype for storing ip address in SQL Server

The technically correct way to store IPv4 is binary(4), since that is what it actually is (no, not even an INT32/INT(4), the numeric textual form that we all know and love (255.255.255.255) being just the display conversion of its binary content).

If you do it this way, you will want functions to convert to and from the textual-display format:

Here's how to convert the textual display form to binary:

CREATE FUNCTION dbo.fnBinaryIPv4(@ip AS VARCHAR(15)) RETURNS BINARY(4)
AS
BEGIN
    DECLARE @bin AS BINARY(4)

    SELECT @bin = CAST( CAST( PARSENAME( @ip, 4 ) AS INTEGER) AS BINARY(1))
                + CAST( CAST( PARSENAME( @ip, 3 ) AS INTEGER) AS BINARY(1))
                + CAST( CAST( PARSENAME( @ip, 2 ) AS INTEGER) AS BINARY(1))
                + CAST( CAST( PARSENAME( @ip, 1 ) AS INTEGER) AS BINARY(1))

    RETURN @bin
END
go

And here's how to convert the binary back to the textual display form:

CREATE FUNCTION dbo.fnDisplayIPv4(@ip AS BINARY(4)) RETURNS VARCHAR(15)
AS
BEGIN
    DECLARE @str AS VARCHAR(15) 

    SELECT @str = CAST( CAST( SUBSTRING( @ip, 1, 1) AS INTEGER) AS VARCHAR(3) ) + '.'
                + CAST( CAST( SUBSTRING( @ip, 2, 1) AS INTEGER) AS VARCHAR(3) ) + '.'
                + CAST( CAST( SUBSTRING( @ip, 3, 1) AS INTEGER) AS VARCHAR(3) ) + '.'
                + CAST( CAST( SUBSTRING( @ip, 4, 1) AS INTEGER) AS VARCHAR(3) );

    RETURN @str
END;
go

Here's a demo of how to use them:

SELECT dbo.fnBinaryIPv4('192.65.68.201')
--should return 0xC04144C9
go

SELECT dbo.fnDisplayIPv4( 0xC04144C9 )
-- should return '192.65.68.201'
go

Finally, when doing lookups and compares, always use the binary form if you want to be able to leverage your indexes.


UPDATE:

I wanted to add that one way to address the inherent performance problems of scalar UDFs in SQL Server, but still retain the code-reuse of a function is to use an iTVF (inline table-valued function) instead. Here's how the first function above (string to binary) can be re-written as an iTVF:

CREATE FUNCTION dbo.itvfBinaryIPv4(@ip AS VARCHAR(15)) RETURNS TABLE
AS RETURN (
    SELECT CAST(
               CAST( CAST( PARSENAME( @ip, 4 ) AS INTEGER) AS BINARY(1))
            +  CAST( CAST( PARSENAME( @ip, 3 ) AS INTEGER) AS BINARY(1))
            +  CAST( CAST( PARSENAME( @ip, 2 ) AS INTEGER) AS BINARY(1))
            +  CAST( CAST( PARSENAME( @ip, 1 ) AS INTEGER) AS BINARY(1))
                AS BINARY(4)) As bin
        )
go

Here's it in the example:

SELECT bin FROM dbo.fnBinaryIPv4('192.65.68.201')
--should return 0xC04144C9
go

And here's how you would use it in an INSERT

INSERT INTo myIpTable
SELECT {other_column_values,...},
       (SELECT bin FROM dbo.itvfBinaryIPv4('192.65.68.201'))

How to load GIF image in Swift?

This is working for me

Podfile:

platform :ios, '9.0'
use_frameworks!

target '<Your Target Name>' do
pod 'SwiftGifOrigin', '~> 1.7.0'
end

Usage:

// An animated UIImage
let jeremyGif = UIImage.gif(name: "jeremy")

// A UIImageView with async loading
let imageView = UIImageView()
imageView.loadGif(name: "jeremy")

// A UIImageView with async loading from asset catalog(from iOS9)
let imageView = UIImageView()
imageView.loadGif(asset: "jeremy")

For more information follow this link: https://github.com/swiftgif/SwiftGif

Socket.IO handling disconnect event

You can also, if you like use socket id to manage your player list like this.

io.on('connection', function(socket){
  socket.on('disconnect', function() {
    console.log("disconnect")
    for(var i = 0; i < onlineplayers.length; i++ ){
      if(onlineplayers[i].socket === socket.id){
        console.log(onlineplayers[i].code + " just disconnected")
        onlineplayers.splice(i, 1)
      }
    }
    io.emit('players', onlineplayers)
  })

  socket.on('lobby_join', function(player) {
    if(player.available === false) return
    var exists = false
    for(var i = 0; i < onlineplayers.length; i++ ){
      if(onlineplayers[i].code === player.code){
        exists = true
      }
    }
    if(exists === false){
      onlineplayers.push({
        code: player.code,
        socket:socket.id
      })
    }
    io.emit('players', onlineplayers)
  })

  socket.on('lobby_leave', function(player) {
    var exists = false
    for(var i = 0; i < onlineplayers.length; i++ ){
      if(onlineplayers[i].code === player.code){
        onlineplayers.splice(i, 1)
      }
    }
    io.emit('players', onlineplayers)
  })
})

Configuration with name 'default' not found. Android Studio

In my setting.gradle, I included a module that does not exist. Once I removed it, it started working. This could be another way to fix this issue

How do I find ' % ' with the LIKE operator in SQL Server?

Try this:

declare @var char(3)
set @var='[%]'
select Address from Accomodation where Address like '%'+@var+'%' 

You must use [] cancels the effect of wildcard, so you read % as a normal character, idem about character _

java get file size efficiently

All the test cases in this post are flawed as they access the same file for each method tested. So disk caching kicks in which tests 2 and 3 benefit from. To prove my point I took test case provided by GHAD and changed the order of enumeration and below are the results.

Looking at result I think File.length() is the winner really.

Order of test is the order of output. You can even see the time taken on my machine varied between executions but File.Length() when not first, and incurring first disk access won.

---
LENGTH sum: 1163351, per Iteration: 4653.404
CHANNEL sum: 1094598, per Iteration: 4378.392
URL sum: 739691, per Iteration: 2958.764

---
CHANNEL sum: 845804, per Iteration: 3383.216
URL sum: 531334, per Iteration: 2125.336
LENGTH sum: 318413, per Iteration: 1273.652

--- 
URL sum: 137368, per Iteration: 549.472
LENGTH sum: 18677, per Iteration: 74.708
CHANNEL sum: 142125, per Iteration: 568.5

How to scanf only integer and repeat reading if the user enters non-numeric characters?

You could create a function that reads an integer between 1 and 23 or returns 0 if non-int

e.g.

int getInt()
{
  int n = 0;
  char buffer[128];
  fgets(buffer,sizeof(buffer),stdin);
  n = atoi(buffer); 
  return ( n > 23 || n < 1 ) ? 0 : n;
}

Find a string by searching all tables in SQL Server Management Studio 2008

A bit late, but you can easily find a string with this query

DECLARE
@search_string  VARCHAR(100),
@table_name     SYSNAME,
@table_id       INT,
@column_name    SYSNAME,
@sql_string     VARCHAR(2000)

SET @search_string = 'StringtoSearch'

DECLARE tables_cur CURSOR FOR SELECT ss.name +'.'+ so.name [name], object_id FROM sys.objects so INNER JOIN sys.schemas ss ON so.schema_id = ss.schema_id WHERE  type = 'U'

OPEN tables_cur

FETCH NEXT FROM tables_cur INTO @table_name, @table_id

WHILE (@@FETCH_STATUS = 0)
BEGIN
    DECLARE columns_cur CURSOR FOR SELECT name FROM sys.columns WHERE object_id = @table_id 
        AND system_type_id IN (167, 175, 231, 239)

    OPEN columns_cur

    FETCH NEXT FROM columns_cur INTO @column_name
        WHILE (@@FETCH_STATUS = 0)
        BEGIN
            SET @sql_string = 'IF EXISTS (SELECT * FROM ' + @table_name + ' WHERE [' + @column_name + '] 
            LIKE ''%' + @search_string + '%'') PRINT ''' + @table_name + ', ' + @column_name + ''''

            EXECUTE(@sql_string)

        FETCH NEXT FROM columns_cur INTO @column_name
        END

    CLOSE columns_cur

DEALLOCATE columns_cur

FETCH NEXT FROM tables_cur INTO @table_name, @table_id
END

CLOSE tables_cur
DEALLOCATE tables_cur

ElasticSearch: Unassigned Shards, how to fix?

Maybe it helps someone, but I had the same issue and it was due to a lack of storage space caused by a log getting way too big.

Hope it helps someone! :)

Android: Cancel Async Task

FOUND THE SOLUTION: I added an action listener before uploadingDialog.show() like this:

    uploadingDialog.setOnCancelListener(new DialogInterface.OnCancelListener(){
          public void onCancel(DialogInterface dialog) {
              myTask.cancel(true);
              //finish();
          }
    });

That way when I press the back button, the above OnCancelListener cancels both dialog and task. Also you can add finish() if you want to finish the whole activity on back pressed. Remember to declare your async task as a variable like this:

    MyAsyncTask myTask=null;

and execute your async task like this:

    myTask = new MyAsyncTask();
    myTask.execute();

Creating a BLOB from a Base64 string in JavaScript

The method with fetch is the best solution, but if anyone needs to use a method without fetch then here it is, as the ones mentioned previously didn't work for me:

function makeblob(dataURL) {
    const BASE64_MARKER = ';base64,';
    const parts = dataURL.split(BASE64_MARKER);
    const contentType = parts[0].split(':')[1];
    const raw = window.atob(parts[1]);
    const rawLength = raw.length;
    const uInt8Array = new Uint8Array(rawLength);

    for (let i = 0; i < rawLength; ++i) {
        uInt8Array[i] = raw.charCodeAt(i);
    }

    return new Blob([uInt8Array], { type: contentType });
}

Required maven dependencies for Apache POI to work

Add these dependencies to your maven pom.xml . It will take care of all of the imports including OPCpackage

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

Get the Application Context In Fragment In Android?

In Support Library 27.1.0 and later, Google has introduced new methods requireContext() and requireActivity() methods.

Eg:ContextCompat.getColor(requireContext(), R.color.soft_gray)

More info here

What is "with (nolock)" in SQL Server?

The simplest answer is a simple question - do you need your results to be repeatable? If yes then NOLOCKS is not appropriate under any circumstances

If you don't need repeatability then nolocks may be useful, especially if you don't have control over all processes connecting to the target database.

How to determine if OpenSSL and mod_ssl are installed on Apache2

Just look in the ssl_engine.log in your Apache log directory where you should find something like:

[ssl:info] [pid 5963:tid 139718276048640] AH01876: mod_ssl/2.4.9 compiled against Server: Apache/2.4.9, Library: OpenSSL/1.0.1h

Given two directory trees, how can I find out which files differ by content?

To find diff use this command:

diff -qr dir1/ dir2/

-r will diff all subdirectories too -q tells diff to report only when files differ.

diff  --brief dir1/ dir2/

--brief will show the files that dosent exist in directory.

Or else

we can use Meld which will show in graphical window its easy to find the difference.

meld  dir1/ dir2/

python ValueError: invalid literal for float()

I would all but guarantee that the issue is some sort of non-printing character that's present in the value you pulled off your socket. It looks like you're using Python 2.x, in which case you can check for them with this:

print repr(temp)

You'll likely see something in there that's escaped in the form \x00. These non-printing characters don't show up when you print directly to the console, but their presence is enough to negatively impact the parsing of a string value into a float.

-- Edited for question changes --

It turns this is partly accurate for your issue - the root cause however appears to be that you're reading more information than you expect from your socket or otherwise receiving multiple values. You could do something like

map(float, temp.strip().split('\r\n'))

In order to convert each of the values, but if your function is supposed to return a single float value this is likely to cause confusion. Anyway, the issue certainly revolves around the presence of characters you did not expect to see in the value you retrieved from your socket.

Trigger change() event when setting <select>'s value with val() function

The straight answer is already in a duplicate question: Why does the jquery change event not trigger when I set the value of a select using val()?

As you probably know setting the value of the select doesn't trigger the change() event, if you're looking for an event that is fired when an element's value has been changed through JS there isn't one.

If you really want to do this I guess the only way is to write a function that checks the DOM on an interval and tracks changed values, but definitely don't do this unless you must (not sure why you ever would need to)

Added this solution:
Another possible solution would be to create your own .val() wrapper function and have it trigger a custom event after setting the value through .val(), then when you use your .val() wrapper to set the value of a <select> it will trigger your custom event which you can trap and handle.

Be sure to return this, so it is chainable in jQuery fashion

Difference between java.exe and javaw.exe

java.exe is the command where it waits for application to complete untill it takes the next command. javaw.exe is the command which will not wait for the application to complete. you can go ahead with another commands.

How to print full stack trace in exception?

I usually use the .ToString() method on exceptions to present the full exception information (including the inner stack trace) in text:

catch (MyCustomException ex)
{
    Debug.WriteLine(ex.ToString());
}

Sample output:

ConsoleApplication1.MyCustomException: some message .... ---> System.Exception: Oh noes!
   at ConsoleApplication1.SomeObject.OtherMethod() in C:\ConsoleApplication1\SomeObject.cs:line 24
   at ConsoleApplication1.SomeObject..ctor() in C:\ConsoleApplication1\SomeObject.cs:line 14
   --- End of inner exception stack trace ---
   at ConsoleApplication1.SomeObject..ctor() in C:\ConsoleApplication1\SomeObject.cs:line 18
   at ConsoleApplication1.Program.DoSomething() in C:\ConsoleApplication1\Program.cs:line 23
   at ConsoleApplication1.Program.Main(String[] args) in C:\ConsoleApplication1\Program.cs:line 13

Converting NSString to NSDictionary / JSON

I believe you are misinterpreting the JSON format for key values. You should store your string as

NSString *jsonString = @"{\"ID\":{\"Content\":268,\"type\":\"text\"},\"ContractTemplateID\":{\"Content\":65,\"type\":\"text\"}}";
NSData *data = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
id json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];

Now if you do following NSLog statement

NSLog(@"%@",[json objectForKey:@"ID"]);

Result would be another NSDictionary.

{
    Content = 268;
    type = text;
}

Hope this helps to get clear understanding.

Error: Registry key 'Software\JavaSoft\Java Runtime Environment'\CurrentVersion'?

set PATH=c:\Program Files\Java\jdk1.6.0_45\bin;%PATH%

this will work if you are working on command prompt

Peak detection in a 2D array

This is an image registration problem. The general strategy is:

  • Have a known example, or some kind of prior on the data.
  • Fit your data to the example, or fit the example to your data.
  • It helps if your data is roughly aligned in the first place.

Here's a rough and ready approach, "the dumbest thing that could possibly work":

  • Start with five toe coordinates in roughly the place you expect.
  • With each one, iteratively climb to the top of the hill. i.e. given current position, move to maximum neighbouring pixel, if its value is greater than current pixel. Stop when your toe coordinates have stopped moving.

To counteract the orientation problem, you could have 8 or so initial settings for the basic directions (North, North East, etc). Run each one individually and throw away any results where two or more toes end up at the same pixel. I'll think about this some more, but this kind of thing is still being researched in image processing - there are no right answers!

Slightly more complex idea: (weighted) K-means clustering. It's not that bad.

  • Start with five toe coordinates, but now these are "cluster centres".

Then iterate until convergence:

  • Assign each pixel to the closest cluster (just make a list for each cluster).
  • Calculate the center of mass of each cluster. For each cluster, this is: Sum(coordinate * intensity value)/Sum(coordinate)
  • Move each cluster to the new centre of mass.

This method will almost certainly give much better results, and you get the mass of each cluster which may help in identifying the toes.

(Again, you've specified the number of clusters up front. With clustering you have to specify the density one way or another: Either choose the number of clusters, appropriate in this case, or choose a cluster radius and see how many you end up with. An example of the latter is mean-shift.)

Sorry about the lack of implementation details or other specifics. I would code this up but I've got a deadline. If nothing else has worked by next week let me know and I'll give it a shot.

Create a date time with month and day only, no year

Well, you can create your own type - but a DateTime always has a full date and time. You can't even have "just a date" using DateTime - the closest you can come is to have a DateTime at midnight.

You could always ignore the year though - or take the current year:

// Consider whether you want DateTime.UtcNow.Year instead
DateTime value = new DateTime(DateTime.Now.Year, month, day);

To create your own type, you could always just embed a DateTime within a struct, and proxy on calls like AddDays etc:

public struct MonthDay : IEquatable<MonthDay>
{
    private readonly DateTime dateTime;

    public MonthDay(int month, int day)
    {
        dateTime = new DateTime(2000, month, day);
    }

    public MonthDay AddDays(int days)
    {
        DateTime added = dateTime.AddDays(days);
        return new MonthDay(added.Month, added.Day);
    }

    // TODO: Implement interfaces, equality etc
}

Note that the year you choose affects the behaviour of the type - should Feb 29th be a valid month/day value or not? It depends on the year...

Personally I don't think I would create a type for this - instead I'd have a method to return "the next time the program should be run".

Can I perform a DNS lookup (hostname to IP address) using client-side Javascript?

I don't think this is allowed by most browsers for security reasons, in a pure JavaScript context as the question asks.

iOS 8 UITableView separator inset 0 not working

Swift 2.0 Extension

I just wanted to share an extension I made to remove the margins from the tableview cell separators.

extension UITableViewCell {
    func removeMargins() {

        if self.respondsToSelector("setSeparatorInset:") {
            self.separatorInset = UIEdgeInsetsZero
        }

        if self.respondsToSelector("setPreservesSuperviewLayoutMargins:") {
            self.preservesSuperviewLayoutMargins = false
        }

        if self.respondsToSelector("setLayoutMargins:") {
            self.layoutMargins = UIEdgeInsetsZero
        }
    }
}

Used in context:

    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! CustomCell

    cell.removeMargins()
    return cell

Create boolean column in MySQL with false as default value?

If you are making the boolean column as not null then the default 'default' value is false; you don't have to explicitly specify it.

Difference between a script and a program?

See:

The Difference Between a Program and a Script

A Script is also a program but without an opaque layer hiding the (source code) whereas a program is one having clothes, you can't see it's source code unless it is decompilable.

Scripts need other programs to execute them while programs don't need one.

redirect COPY of stdout to log file from within bash script itself

Bash 4 has a coproc command which establishes a named pipe to a command and allows you to communicate through it.

How to apply font anti-alias effects in CSS?

Works the best. If you want to use it sitewide, without having to add this syntax to every class or ID, add the following CSS to your css body:

body { 
    -webkit-font-smoothing: antialiased;
    text-shadow: 1px 1px 1px rgba(0,0,0,0.004);
    background: url('./images/background.png');
    text-align: left;
    margin: auto;

}

Initialize static variables in C++ class?

Just to add on top of the other answers. In order to initialize a complex static member, you can do it as follows:

Declare your static member as usual.

// myClass.h
class myClass
{
static complexClass s_complex;
//...
};

Make a small function to initialize your class if it's not trivial to do so. This will be called just the one time the static member is initialized. (Note that the copy constructor of complexClass will be used, so it should be well defined).

//class.cpp    
#include myClass.h
complexClass initFunction()
{
    complexClass c;
    c.add(...);
    c.compute(...);
    c.sort(...);
    // Etc.
    return c;
}

complexClass myClass::s_complex = initFunction();

Return file in ASP.Net Core Web API

If this is ASP.net-Core then you are mixing web API versions. Have the action return a derived IActionResult because in your current code the framework is treating HttpResponseMessage as a model.

[Route("api/[controller]")]
public class DownloadController : Controller {
    //GET api/download/12345abc
    [HttpGet("{id}"]
    public async Task<IActionResult> Download(string id) {
        Stream stream = await {{__get_stream_based_on_id_here__}}

        if(stream == null)
            return NotFound(); // returns a NotFoundResult with Status404NotFound response.

        return File(stream, "application/octet-stream"); // returns a FileStreamResult
    }    
}

What is difference between XML Schema and DTD?

DTD predates XML and is therefore not valid XML itself. That's probably the biggest reason for XSD's invention.

How to set an environment variable only for the duration of the script?

Just put

export HOME=/blah/whatever

at the point in the script where you want the change to happen. Since each process has its own set of environment variables, this definition will automatically cease to have any significance when the script terminates (and with it the instance of bash that has a changed environment).

Android Material Design Button Styles

I tried a lot of answer & third party libs, but none was keeping the border and raised effect on pre-lollipop while having the ripple effect on lollipop without drawback. Here is my final solution combining several answers (border/raised are not well rendered on gifs due to grayscale color depth) :

Lollipop

enter image description here

Pre-lollipop

enter image description here

build.gradle

compile 'com.android.support:cardview-v7:23.1.1'

layout.xml

<android.support.v7.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:id="@+id/card"
    card_view:cardElevation="2dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    card_view:cardMaxElevation="8dp"
    android:layout_margin="6dp"
    >
    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="0dp"
        android:background="@drawable/btn_bg"
        android:text="My button"/>
</android.support.v7.widget.CardView>

drawable-v21/btn_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="?attr/colorControlHighlight">
    <item android:drawable="?attr/colorPrimary"/>
</ripple>

drawable/btn_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@color/colorPrimaryDark" android:state_pressed="true"/>
    <item android:drawable="@color/colorPrimaryDark" android:state_focused="true"/>
    <item android:drawable="@color/colorPrimary"/>
</selector>

Activity's onCreate

    final CardView cardView = (CardView) findViewById(R.id.card);
    final Button button = (Button) findViewById(R.id.button);
    button.setOnTouchListener(new View.OnTouchListener() {
        ObjectAnimator o1 = ObjectAnimator.ofFloat(cardView, "cardElevation", 2, 8)
                .setDuration
                        (80);
        ObjectAnimator o2 = ObjectAnimator.ofFloat(cardView, "cardElevation", 8, 2)
                .setDuration
                        (80);

        @Override
        public boolean onTouch(View v, MotionEvent event) {

            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    o1.start();
                    break;
                case MotionEvent.ACTION_CANCEL:
                case MotionEvent.ACTION_UP:
                    o2.start();
                    break;
            }
            return false;
        }
    });

Storing Python dictionaries

My use case was to save multiple JSON objects to a file and marty's answer helped me somewhat. But to serve my use case, the answer was not complete as it would overwrite the old data every time a new entry was saved.

To save multiple entries in a file, one must check for the old content (i.e., read before write). A typical file holding JSON data will either have a list or an object as root. So I considered that my JSON file always has a list of objects and every time I add data to it, I simply load the list first, append my new data in it, and dump it back to a writable-only instance of file (w):

def saveJson(url,sc): # This function writes the two values to the file
    newdata = {'url':url,'sc':sc}
    json_path = "db/file.json"

    old_list= []
    with open(json_path) as myfile:  # Read the contents first
        old_list = json.load(myfile)
    old_list.append(newdata)

    with open(json_path,"w") as myfile:  # Overwrite the whole content
        json.dump(old_list, myfile, sort_keys=True, indent=4)

    return "success"

The new JSON file will look something like this:

[
    {
        "sc": "a11",
        "url": "www.google.com"
    },
    {
        "sc": "a12",
        "url": "www.google.com"
    },
    {
        "sc": "a13",
        "url": "www.google.com"
    }
]

NOTE: It is essential to have a file named file.json with [] as initial data for this approach to work

PS: not related to original question, but this approach could also be further improved by first checking if our entry already exists (based on one or multiple keys) and only then append and save the data.

How to do vlookup and fill down (like in Excel) in R?

Starting with:

houses <- read.table(text="Semi            1
Single          2
Row             3
Single          2
Apartment       4
Apartment       4
Row             3",col.names=c("HouseType","HouseTypeNo"))

... you can use

as.numeric(factor(houses$HouseType))

... to give a unique number for each house type. You can see the result here:

> houses2 <- data.frame(houses,as.numeric(factor(houses$HouseType)))
> houses2
  HouseType HouseTypeNo as.numeric.factor.houses.HouseType..
1      Semi           1                                    3
2    Single           2                                    4
3       Row           3                                    2
4    Single           2                                    4
5 Apartment           4                                    1
6 Apartment           4                                    1
7       Row           3                                    2

... so you end up with different numbers on the rows (because the factors are ordered alphabetically) but the same pattern.

(EDIT: the remaining text in this answer is actually redundant. It occurred to me to check and it turned out that read.table() had already made houses$HouseType into a factor when it was read into the dataframe in the first place).

However, you may well be better just to convert HouseType to a factor, which would give you all the same benefits as HouseTypeNo, but would be easier to interpret because the house types are named rather than numbered, e.g.:

> houses3 <- houses
> houses3$HouseType <- factor(houses3$HouseType)
> houses3
  HouseType HouseTypeNo
1      Semi           1
2    Single           2
3       Row           3
4    Single           2
5 Apartment           4
6 Apartment           4
7       Row           3
> levels(houses3$HouseType)
[1] "Apartment" "Row"       "Semi"      "Single"  

Vue js error: Component template should contain exactly one root element

Note This answer only applies to version 2.x of Vue. Version 3 has lifted this restriction.

You have two root elements in your template.

<div class="form-group">
  ...
</div>
<div class="col-md-6">
  ...
</div>

And you need one.

<div>
    <div class="form-group">
      ...
    </div>

    <div class="col-md-6">
      ...
    </div>
</div>

Essentially in Vue you must have only one root element in your templates.

Setting default values to null fields when mapping with Jackson

Make the member private and add a setter/getter pair. In your setter, if null, then set default value instead. Additionally, I have shown the snippet with the getter also returning a default when internal value is null.

class JavaObject {
    private static final String DEFAULT="Default Value";

    public JavaObject() {
    }

    @NotNull
    private String notNullMember;
    public void setNotNullMember(String value){
            if (value==null) { notNullMember=DEFAULT; return; }
            notNullMember=value;
            return;
    }

    public String getNotNullMember(){
            if (notNullMember==null) { return DEFAULT;}
            return notNullMember;
    }

    public String optionalMember;
}

Array to Hash Ruby

You could try like this, for single array

irb(main):019:0> a = ["item 1", "item 2", "item 3", "item 4"]
  => ["item 1", "item 2", "item 3", "item 4"]
irb(main):020:0> Hash[*a]
  => {"item 1"=>"item 2", "item 3"=>"item 4"}

for array of array

irb(main):022:0> a = [[1, 2], [3, 4]]
  => [[1, 2], [3, 4]]
irb(main):023:0> Hash[*a.flatten]
  => {1=>2, 3=>4}

sys.path different in Jupyter and Python - how to import own modules in Jupyter?

Suppose your project has the following structure and you want to do imports in the notebook.ipynb:

/app
  /mypackage
    mymodule.py
  /notebooks
    notebook.ipynb

If you are running Jupyter inside a docker container without any virtualenv it might be useful to create Jupyter (ipython) config in your project folder:

/app
  /profile_default
    ipython_config.py

Content of ipython_config.py:

c.InteractiveShellApp.exec_lines = [
    'import sys; sys.path.append("/app")'
]

Open the notebook and check it out:

print(sys.path)

['', '/usr/local/lib/python36.zip', '/usr/local/lib/python3.6', '/usr/local/lib/python3.6/lib-dynload', '/usr/local/lib/python3.6/site-packages', '/usr/local/lib/python3.6/site-packages/IPython/extensions', '/root/.ipython', '/app']

Now you can do imports in your notebook without any sys.path appending in the cells:

from mypackage.mymodule import myfunc

How to install PyQt4 on Windows using pip?

It looks like you may have to do a bit of manual installation for PyQt4.

http://pyqt.sourceforge.net/Docs/PyQt4/installation.html

This might help a bit more, it's a bit more in a tutorial/set-by-step format:

http://movingthelamppost.com/blog/html/2013/07/12/installing_pyqt____because_it_s_too_good_for_pip_or_easy_install_.html

Where to find extensions installed folder for Google Chrome on Mac?

The default locations of Chrome's profile directory are defined at http://www.chromium.org/user-experience/user-data-directory. For Chrome on Mac, it's

~/Library/Application\ Support/Google/Chrome/Default

The actual location can be different, by setting the --user-data-dir=path/to/directory flag.
If only one user is registered in Chrome, look in the Default/Extensions subdirectory. Otherwise, look in the <profile user name>/Extensions directory.

If that didn't help, you can always do a custom search.

  1. Go to chrome://extensions/, and find out the ID of an extension (32 lowercase letters) (if not done already, activate "Developer mode" first).

  2. Open the terminal, cd to the directory which is most likely a parent of your Chrome profile (if unsure, try ~ then /).

  3. Run find . -type d -iname "<EXTENSION ID HERE>", for example:

    find . -type d -iname jifpbeccnghkjeaalbbjmodiffmgedin
    

    Result:

    ./Library/Application Support/Google/Chrome/Default/Extensions/jifpbeccnghkjeaalbbjmodiffmgedin

Chrome:The website uses HSTS. Network errors...this page will probably work later

When you visited https://localhost previously at some point it not only visited this over a secure channel (https rather than http), it also told your browser, using a special HTTP header: Strict-Transport-Security (often abbreviated to HSTS), that it should ONLY use https for all future visits.

This is a security feature web servers can use to prevent people being downgraded to http (either intentionally or by some evil party).

However if you then then turn off your https server, and just want to browse http you can't (by design - that's the point of this security feature).

HSTS also does prevents you from accepting and skipping past certificate errors.

To reset this, so HSTS is no longer set for localhost, type the following in your Chrome address bar:

chrome://net-internals/#hsts

Where you will be able to delete this setting for "localhost".

You might also want to find out what was setting this to avoid this problem in future!

Note that for other sites (e.g. www.google.com) these are "preloaded" into the Chrome code and so cannot be removed. When you query them at chrome://net-internals/#hsts you will see them listed as static HSTS entries.

And finally note that Google has started preloading HSTS for the entire .dev domain: https://ma.ttias.be/chrome-force-dev-domains-https-via-preloaded-hsts/

Using Java 8's Optional with Stream::flatMap

Most likely You are doing it wrong.

Java 8 Optional is not meant to be used in this manner. It is usually only reserved for terminal stream operations that may or may not return a value, like find for example.

In your case it might be better to first try to find a cheap way to filter out those items that are resolvable and then get the first item as an optional and resolve it as a last operation. Better yet - instead of filtering, find the first resolvable item and resolve it.

things.filter(Thing::isResolvable)
      .findFirst()
      .flatMap(this::resolve)
      .get();

Rule of thumb is that you should strive to reduce number of items in the stream before you transform them to something else. YMMV of course.

Excel select a value from a cell having row number calculated

You could use the INDIRECT function. This takes a string and converts it into a range

More info here

=INDIRECT("K"&A2)

But it's preferable to use INDEX as it is less volatile.

=INDEX(K:K,A2)

This returns a value or the reference to a value from within a table or range

More info here

Put either function into cell B2 and fill down.

How to overcome root domain CNAME restrictions?

My company does the same thing for a number of customers where we host a web site for them although in our case it's xyz.company.com rather than www.company.com. We do get them to set the A record on xyz.company.com to point to an IP address we allocate them.

As to how you could cope with a change in IP address I don't think there is a perfect solution. Some ideas are:

  • Use a NAT or IP load balancer and give your customers an IP address belonging to it. If the IP address of the web server needs to change you could make an update on the NAT or load balancer,

  • Offer a DNS hosting service as well and get your customers to host their domain with you so that you'd be in a position to update the A records,

  • Get your customers to set their A record up to one main web server and use a HTTP redirect for each customer's web requests.

Logarithmic returns in pandas dataframe

The results might seem similar, but that is just because of the Taylor expansion for the logarithm. Since log(1 + x) ~ x, the results can be similar.

However,

I am using the following code to get logarithmic returns, but it gives the exact same values as the pct.change() function.

is not quite correct.

import pandas as pd

df = pd.DataFrame({'p': range(10)})

df['pct_change'] = df.pct_change()
df['log_stuff'] = \
    np.log(df['p'].astype('float64')/df['p'].astype('float64').shift(1))
df[['pct_change', 'log_stuff']].plot();

enter image description here

how to read System environment variable in Spring applicationContext

Yes, you can do <property name="defaultLocale" value="#{ systemProperties['user.region']}"/> for instance.

The variable systemProperties is predefined, see 6.4.1 XML based configuration.

Django check for any exists for a query

this worked for me!

if some_queryset.objects.all().exists(): print("this table is not empty")

Map and filter an array at the same time

Direct use of .reduce can be hard to read, so I'd recommend creating a function that generates the reducer for you:

function mapfilter(mapper) {
  return (acc, val) => {
    const mapped = mapper(val);
    if (mapped !== false)
      acc.push(mapped);
    return acc;
  };
}

Use it like so:

const words = "Map and filter an array #javascript #arrays";
const tags = words.split(' ')
  .reduce(mapfilter(word => word.startsWith('#') && word.slice(1)), []);
console.log(tags);  // ['javascript', 'arrays'];

How to preview an image before and after upload?

On input type=file add an event onchange="preview()"

For the function preview() type:

thumb.src=URL.createObjectURL(event.target.files[0]);

Live example:

_x000D_
_x000D_
function preview() {
   thumb.src=URL.createObjectURL(event.target.files[0]);
}
_x000D_
<form>
    <input type="file" onchange="preview()">
    <img id="thumb" src="" width="150px"/>
</form>
_x000D_
_x000D_
_x000D_

Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]

I had a similar problem and after going over a lot on stack overflow and spending time on the jar dependencies, I figured out that in my case, I had two sets of asm.jar. I removed one of them and it worked fine...

How do I put an already-running process under nohup?

Using the Job Control of bash to send the process into the background:

  1. Ctrl+Z to stop (pause) the program and get back to the shell.
  2. bg to run it in the background.
  3. disown -h [job-spec] where [job-spec] is the job number (like %1 for the first running job; find about your number with the jobs command) so that the job isn't killed when the terminal closes.

How to find files recursively by file type and copy them to a directory while in ssh?

Something like this should work.

ssh [email protected] 'find -type f -name "*.pdf" -exec cp {} ./pdfsfolder \;'

this.getClass().getClassLoader().getResource("...") and NullPointerException

I had the same issue working on a project with Maven. Here how I fixed it: I just put the sources (images, musics and other stuffs) in the resources directory:

src/main/resources

I created the same structure for the packages in the resources directory too. For example:

If my class is on

com.package1.main

In the resources directory I put one package with the same name

com.package1.main

So I use

getClass().getResource("resource.png");

Animate text change in UILabel

I wonder if it works, and it works perfectly!

Objective-C

[UIView transitionWithView:self.label 
                  duration:0.25f 
                   options:UIViewAnimationOptionTransitionCrossDissolve 
                animations:^{

    self.label.text = rand() % 2 ? @"Nice nice!" : @"Well done!";

  } completion:nil];

Swift 3, 4, 5

UIView.transition(with: label,
              duration: 0.25,
               options: .transitionCrossDissolve,
            animations: { [weak self] in
                self?.label.text = (arc4random()() % 2 == 0) ? "One" : "Two"
         }, completion: nil)

How to use the addr2line command in Linux?

Try adding the -f option to show the function names :

addr2line -f -e a.out 0x4005BDC

How do I get an element to scroll into view, using jQuery?

Simple 2 steps for scrolling down to end or bottom.

Step1: get the full height of scrollable(conversation) div.

Step2: apply scrollTop on that scrollable(conversation) div using the value obtained in step1.

var fullHeight = $('#conversation')[0].scrollHeight;

$('#conversation').scrollTop(fullHeight);

Above steps must be applied for every append on the conversation div.

ASP.NET MVC: No parameterless constructor defined for this object

I just had a similar problem. The same exception occurs when a Model has no parameterless constructor.

The call stack was figuring a method responsible for creating a new instance of a model.

System.Web.Mvc.DefaultModelBinder.CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType)


Here is a sample:

public class MyController : Controller
{
    public ActionResult Action(MyModel model)
    {

    }
}

public class MyModel
{
    public MyModel(IHelper helper) // MVC cannot call that
    {
        // ...
    }

    public MyModel() // MVC can call that
    {
    }
}

PHP Unset Session Variable

// set
$_SESSION['test'] = 1;

// destroy
unset($_SESSION['test']);

How to remove underline from a name on hover

_x000D_
_x000D_
legend.green-color{_x000D_
    color:green !important;_x000D_
}
_x000D_
_x000D_
_x000D_

Ansible - Use default if a variable is not defined

If you have a single play that you want to loop over the items, define that list in group_vars/all or somewhere else that makes sense:

all_items:
  - first
  - second
  - third
  - fourth

Then your task can look like this:

  - name: List items or default list
    debug:
      var: item
    with_items: "{{ varlist | default(all_items) }}"

Pass in varlist as a JSON array:

ansible-playbook <playbook_name> --extra-vars='{"varlist": [first,third]}'

Prior to that, you might also want a task that checks that each item in varlist is also in all_items:

  - name: Ensure passed variables are in all_items
    fail:
      msg: "{{ item }} not  in all_items list"
    when: item not in all_items
    with_items: "{{ varlist | default(all_items) }}"

How to remove "index.php" in codeigniter's path

place a .htaccess file in your root web directory

Whatsoever tweaking you do - if the above is not met - it will not work. Usually its in the System folder, it should be in the root. Cheers!

Capturing URL parameters in request.GET

You might as well check request.META dictionary to access many useful things like PATH_INFO, QUERY_STRING

# for example
request.META['QUERY_STRING']

# or to avoid any exceptions provide a fallback

request.META.get('QUERY_STRING', False)

you said that it returns empty query dict

I think you need to tune your url to accept required or optional args or kwargs Django got you all the power you need with regrex like:

url(r'^project_config/(?P<product>\w+)/$', views.foo),

more about this at django-optional-url-parameters

Count number of objects in list

You can also use unlist(), which is often useful for handling lists:

> mylist <- list(A = c(1:3), B = c(4:6), C = c(7:9))

> mylist
$A
[1] 1 2 3

$B
[1] 4 5 6

$C
[1] 7 8 9

> unlist(mylist)
A1 A2 A3 B1 B2 B3 C1 C2 C3 
 1  2  3  4  5  6  7  8  9 

> length(unlist(mylist))
[1] 9

unlist() is a simple way of executing other functions on lists as well, such as:

> sum(mylist)
Error in sum(mylist) : invalid 'type' (list) of argument

> sum(unlist(mylist))
[1] 45

Convert json to a C# array?

Old question but worth adding an answer if using .NET Core 3.0 or later. JSON serialization/deserialization is built into the framework (System.Text.Json), so you don't have to use third party libraries any more. Here's an example based off the top answer given by @Icarus

using System;
using System.Collections.Generic;

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            var json = "[{\"Name\":\"John Smith\", \"Age\":35}, {\"Name\":\"Pablo Perez\", \"Age\":34}]";

            // use the built in Json deserializer to convert the string to a list of Person objects
            var people = System.Text.Json.JsonSerializer.Deserialize<List<Person>>(json);

            foreach (var person in people)
            {
                Console.WriteLine(person.Name + " is " + person.Age + " years old.");
            }
        }

        public class Person
        {
            public int Age { get; set; }
            public string Name { get; set; }
        }
    }
}

Image library for Python 3

The "friendly PIL fork" Pillow works on Python 2 and 3. Check out the Github project for support matrix and so on.

JQuery, Spring MVC @RequestBody and JSON - making it work together

I'm pretty sure you only have to register MappingJacksonHttpMessageConverter

(the easiest way to do that is through <mvc:annotation-driven /> in XML or @EnableWebMvc in Java)

See:


Here's a working example:

Maven POM

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion><groupId>test</groupId><artifactId>json</artifactId><packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version><name>json test</name>
    <dependencies>
        <dependency><!-- spring mvc -->
            <groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>3.0.5.RELEASE</version>
        </dependency>
        <dependency><!-- jackson -->
            <groupId>org.codehaus.jackson</groupId><artifactId>jackson-mapper-asl</artifactId><version>1.4.2</version>
        </dependency>
    </dependencies>
    <build><plugins>
            <!-- javac --><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId>
            <version>2.3.2</version><configuration><source>1.6</source><target>1.6</target></configuration></plugin>
            <!-- jetty --><plugin><groupId>org.mortbay.jetty</groupId><artifactId>jetty-maven-plugin</artifactId>
            <version>7.4.0.v20110414</version></plugin>
    </plugins></build>
</project>

in folder src/main/webapp/WEB-INF

web.xml

<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
    version="2.4">
    <servlet><servlet-name>json</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>json</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

json-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
                        http://www.springframework.org/schema/beans/spring-beans.xsd">

    <import resource="classpath:mvc-context.xml" />

</beans>

in folder src/main/resources:

mvc-context.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <mvc:annotation-driven />
    <context:component-scan base-package="test.json" />
</beans>

In folder src/main/java/test/json

TestController.java

@Controller
@RequestMapping("/test")
public class TestController {

    @RequestMapping(method = RequestMethod.POST, value = "math")
    @ResponseBody
    public Result math(@RequestBody final Request request) {
        final Result result = new Result();
        result.setAddition(request.getLeft() + request.getRight());
        result.setSubtraction(request.getLeft() - request.getRight());
        result.setMultiplication(request.getLeft() * request.getRight());
        return result;
    }

}

Request.java

public class Request implements Serializable {
    private static final long serialVersionUID = 1513207428686438208L;
    private int left;
    private int right;
    public int getLeft() {return left;}
    public void setLeft(int left) {this.left = left;}
    public int getRight() {return right;}
    public void setRight(int right) {this.right = right;}
}

Result.java

public class Result implements Serializable {
    private static final long serialVersionUID = -5054749880960511861L;
    private int addition;
    private int subtraction;
    private int multiplication;

    public int getAddition() { return addition; }
    public void setAddition(int addition) { this.addition = addition; }
    public int getSubtraction() { return subtraction; }
    public void setSubtraction(int subtraction) { this.subtraction = subtraction; }
    public int getMultiplication() { return multiplication; }
    public void setMultiplication(int multiplication) { this.multiplication = multiplication; }
}

You can test this setup by executing mvn jetty:run on the command line, and then sending a POST request:

URL:        http://localhost:8080/test/math
mime type:  application/json
post body:  { "left": 13 , "right" : 7 }

I used the Poster Firefox plugin to do this.

Here's what the response looks like:

{"addition":20,"subtraction":6,"multiplication":91}

Input button target="_blank" isn't causing the link to load in a new window/tab

you will need to do it like this...

<a type="button" href="http://www.facebook.com/" value="facebook" target="_blank" class="button"></a>

and add the basic css if you want it to look like a btn.. like this

    .button {
    width:100px;
    height:50px;
    -moz-box-shadow:inset 0 1px 0 0 #fff;
    -webkit-box-shadow:inset 0 1px 0 0 #fff;
    box-shadow:inset 0 1px 0 0 #fff;
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #ffffff), color-stop(1, #d1d1d1) );
    background:-moz-linear-gradient( center top, #ffffff 5%, #d1d1d1 100% );
 filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffffff', endColorstr='#d1d1d1');
    background-color:#fff;
    -moz-border-radius:6px;
    -webkit-border-radius:6px;
    border-radius:6px;
    border:1px solid #dcdcdc;
    display:inline-block;
    color:#777;
    font-family:Helvetica;
    font-size:15px;
    font-weight:700;
    padding:6px 24px;
    text-decoration:none;
    text-shadow:1px 1px 0 #fff
}



  .button:hover {
    background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #d1d1d1), color-stop(1, #ffffff) );
    background:-moz-linear-gradient( center top, #d1d1d1 5%, #ffffff 100% );
 filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#d1d1d1', endColorstr='#ffffff');
    background-color:#d1d1d1
}
.button:active {
    position:relative;
    top:1px
}

target works only with href tags..

How to get everything after last slash in a URL?

First extract the path element from the URL:

from urllib.parse import urlparse
parsed= urlparse('https://www.dummy.example/this/is/PATH?q=/a/b&r=5#asx')

and then you can extract the last segment with string functions:

parsed.path.rpartition('/')[2]

(example resulting to 'PATH')

How to import a Python class that is in a directory above?

Import module from a directory which is exactly one level above the current directory:

from .. import module

Unable to copy ~/.ssh/id_rsa.pub

add by user root this command : ssh user_to_acces@hostName -X

user_to_acces = user hostName = hostname machine

Http Servlet request lose params from POST body after read it once

First of all we should not read parameters within the filter. Usually the headers are read in the filter to do few authentication tasks. Having said that one can read the HttpRequest body completely in the Filter or Interceptor by using the CharStreams:

String body = com.google.common.io.CharStreams.toString(request.getReader());

This does not affect the subsequent reads at all.

invalid conversion from 'const char*' to 'char*'

string::c.str() returns a string of type const char * as seen here

A quick fix: try casting printfunc(num,addr,(char *)data.str().c_str());

While the above may work, it is undefined behaviour, and unsafe.

Here's a nicer solution using templates:

char * my_argument = const_cast<char*> ( ...c_str() );

How can I make a JUnit test wait?

Thread.sleep() could work in most cases, but usually if you're waiting, you are actually waiting for a particular condition or state to occur. Thread.sleep() does not guarantee that whatever you're waiting for has actually happened.

If you are waiting on a rest request for example maybe it usually return in 5 seconds, but if you set your sleep for 5 seconds the day your request comes back in 10 seconds your test is going to fail.

To remedy this JayWay has a great utility called Awatility which is perfect for ensuring that a specific condition occurs before you move on.

It has a nice fluent api as well

await().until(() -> 
{
    return yourConditionIsMet();
});  

https://github.com/jayway/awaitility

How do you do relative time in Rails?

If you're building a Rails application, you should use

Time.zone.now
Time.zone.today
Time.zone.yesterday

This gives you time or date in the timezone with which you've configured your Rails application.

For example, if you configure your application to use UTC, then Time.zone.now will always be in UTC time (it won't be impacted by the change of British Summertime for example).

Calculating relative time is easy, eg

Time.zone.now - 10.minute
Time.zone.today.days_ago(5)

Running a cron every 30 seconds

You can check out my answer to this similar question

Basically, I've included there a bash script named "runEvery.sh" which you can run with cron every 1 minute and pass as arguments the real command you wish to run and the frequency in seconds in which you want to run it.

something like this

* * * * * ~/bin/runEvery.sh 5 myScript.sh

How to convert a Title to a URL slug in jQuery?

You can use your own function for this.

try it: http://jsfiddle.net/xstLr7aj/

function string_to_slug(str) {
  str = str.replace(/^\s+|\s+$/g, ''); // trim
  str = str.toLowerCase();

  // remove accents, swap ñ for n, etc
  var from = "àáäâèéëêìíïîòóöôùúüûñç·/_,:;";
  var to   = "aaaaeeeeiiiioooouuuunc------";
  for (var i=0, l=from.length ; i<l ; i++) {
    str = str.replace(new RegExp(from.charAt(i), 'g'), to.charAt(i));
  }

  str = str.replace(/[^a-z0-9 -]/g, '') // remove invalid chars
    .replace(/\s+/g, '-') // collapse whitespace and replace by -
    .replace(/-+/g, '-'); // collapse dashes

  return str;
}
$(document).ready(function() {
    $('#test').submit(function(){
        var val = string_to_slug($('#t').val());
        alert(val);
        return false;
    });
});

IEnumerable<object> a = new IEnumerable<object>(); Can I do this?

You can for example create an instance of List<object>, which implements IEnumerable<object>. Example:

List<object> list = new List<object>();
list.Add(1);
list.Add(4);
list.Add(5);

IEnumerable<object> en = list;
CallFunction(en);

What are the advantages of Sublime Text over Notepad++ and vice-versa?

One thing that should be considered is licensing.

Notepad++ is free (as in speech and as in beer) for perpetual use, released under the GPL license, whereas Sublime Text 2 requires a license.

To quote the Sublime Text 2 website:

..a license must be purchased for continued use. There is currently no enforced time limit for the evaluation.

The same is now true of Sublime Text 3, and a paid upgrade will be needed for future versions.

Upgrade Policy A license is valid for Sublime Text 3, and includes all point updates, as well as access to prior versions (e.g., Sublime Text 2). Future major versions, such as Sublime Text 4, will be a paid upgrade.

This licensing requirement is still correct as of Dec 2019.

Inheritance and Overriding __init__ in python

The book is a bit dated with respect to subclass-superclass calling. It's also a little dated with respect to subclassing built-in classes.

It looks like this nowadays:

class FileInfo(dict):
    """store file metadata"""
    def __init__(self, filename=None):
        super(FileInfo, self).__init__()
        self["name"] = filename

Note the following:

  1. We can directly subclass built-in classes, like dict, list, tuple, etc.

  2. The super function handles tracking down this class's superclasses and calling functions in them appropriately.

What is the total amount of public IPv4 addresses?

According to Reserved IP addresses there are 588,514,304 reserved addresses and since there are 4,294,967,296 (2^32) IPv4 addressess in total, there are 3,706,452,992 public addresses.

And too many addresses in this post.

Binning column with python pandas

Using numba module for speed up.

On big datasets (500k >) pd.cut can be quite slow for binning data.

I wrote my own function in numba with just in time compilation, which is roughly 16x faster:

from numba import njit

@njit
def cut(arr):
    bins = np.empty(arr.shape[0])
    for idx, x in enumerate(arr):
        if (x >= 0) & (x < 1):
            bins[idx] = 1
        elif (x >= 1) & (x < 5):
            bins[idx] = 2
        elif (x >= 5) & (x < 10):
            bins[idx] = 3
        elif (x >= 10) & (x < 25):
            bins[idx] = 4
        elif (x >= 25) & (x < 50):
            bins[idx] = 5
        elif (x >= 50) & (x < 100):
            bins[idx] = 6
        else:
            bins[idx] = 7

    return bins
cut(df['percentage'].to_numpy())

# array([5., 5., 7., 5.])

Optional: you can also map it to bins as strings:

a = cut(df['percentage'].to_numpy())

conversion_dict = {1: 'bin1',
                   2: 'bin2',
                   3: 'bin3',
                   4: 'bin4',
                   5: 'bin5',
                   6: 'bin6',
                   7: 'bin7'}

bins = list(map(conversion_dict.get, a))

# ['bin5', 'bin5', 'bin7', 'bin5']

Speed comparison:

# create dataframe of 8 million rows for testing
dfbig = pd.concat([df]*2000000, ignore_index=True)

dfbig.shape

# (8000000, 1)
%%timeit
cut(dfbig['percentage'].to_numpy())

# 38 ms ± 616 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
%%timeit
bins = [0, 1, 5, 10, 25, 50, 100]
labels = [1,2,3,4,5,6]
pd.cut(dfbig['percentage'], bins=bins, labels=labels)

# 215 ms ± 9.76 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

jQuery animate scroll

var page_url = windws.location.href;
var page_id = page_url.substring(page_url.lastIndexOf("#") + 1);
if (page_id == "") {
    $("html, body").animate({
        scrollTop: $("#scroll-" + page_id).offset().top
    }, 2000)
} else if (page_id == "") {
    $("html, body").animate({
        scrollTop: $("#scroll-" + page_id).offset().top
    }, 2000)
}

});

How to Alter Constraint

You can not alter constraints ever but you can drop them and then recreate.

Have look on this

ALTER TABLE your_table DROP CONSTRAINT ACTIVEPROG_FKEY1;

and then recreate it with ON DELETE CASCADE like this

ALTER TABLE your_table
add CONSTRAINT ACTIVEPROG_FKEY1 FOREIGN KEY(ActiveProgCode) REFERENCES PROGRAM(ActiveProgCode)
    ON DELETE CASCADE;

hope this help

How to fix C++ error: expected unqualified-id

As a side note, consider passing strings in setWord() as const references to avoid excess copying. Also, in displayWord, consider making this a const function to follow const-correctness.

void setWord(const std::string& word) {
  theWord = word;
}

Can I set max_retries for requests.request?

Be careful, Martijn Pieters's answer isn't suitable for version 1.2.1+. You can't set it globally without patching the library.

You can do this instead:

import requests
from requests.adapters import HTTPAdapter

s = requests.Session()
s.mount('http://www.github.com', HTTPAdapter(max_retries=5))
s.mount('https://www.github.com', HTTPAdapter(max_retries=5))

Grep for beginning and end of line?

It looks like you were on the right track... The ^ character matches beginning-of-line, and $ matches end-of-line. Jonathan's pattern will work for you... just wanted to give you the explanation behind it

Output of git branch in tree like fashion

For those who use Github, they have a branch network viewer that seems easier to read

How to handle authentication popup with Selenium WebDriver using Java

This should work for Firefox by using AutoAuth plugin:

FirefoxProfile firefoxProfile = new ProfilesIni().getProfile("default");
File ffPluginAutoAuth = new File("D:\\autoauth-2.1-fx+fn.xpi");
firefoxProfile.addExtension(ffPluginAutoAuth);
driver = new FirefoxDriver(firefoxProfile);

What is "runtime"?

Run time is the instance where you don't know about of what type of objects creates during its execution, objects creation are based on certain condition or some computation work. In contradict, compile time is the instance where required objects are defined by you before its executions.

How to use mod operator in bash?

This might be off-topic. But for the wget in for loop, you can certainly do

curl -O http://example.com/search/link[1-600]

UL or DIV vertical scrollbar

Sometimes it is not eligible to set height to pixel values. However, it is possible to show vertical scrollbar through setting height of div to 100% and overflow to auto.

Let me show an example:

<div id="content" style="height: 100%; overflow: auto">
  <p>some text</p>
  <ul>
    <li>text</li>
    .....
    <li>text</li>
</div>

How to put a jar in classpath in Eclipse?

As of rev 17 of the Android Developer Tools, the correct way to add a library jar when.using the tools and Eclipse is to create a directory called libs on the same level as your src and assets directories and then drop the jar in there. Nothing else.required, the tools take care of all the rest for you automatically.

How does facebook, gmail send the real time notification?

Update

As I continue to recieve upvotes on this, I think it is reasonable to remember that this answer is 4 years old. Web has grown in a really fast pace, so please be mindful about this answer.


I had the same issue recently and researched about the subject.

The solution given is called long polling, and to correctly use it you must be sure that your AJAX request has a "large" timeout and to always make this request after the current ends (timeout, error or success).

Long Polling - Client

Here, to keep code short, I will use jQuery:

function pollTask() { 

    $.ajax({

        url: '/api/Polling',
        async: true,            // by default, it's async, but...
        dataType: 'json',       // or the dataType you are working with
        timeout: 10000,          // IMPORTANT! this is a 10 seconds timeout
        cache: false

    }).done(function (eventList) {  

       // Handle your data here
       var data;
       for (var eventName in eventList) {

            data = eventList[eventName];
            dispatcher.handle(eventName, data); // handle the `eventName` with `data`

       }

    }).always(pollTask);

}

It is important to remember that (from jQuery docs):

In jQuery 1.4.x and below, the XMLHttpRequest object will be in an invalid state if the request times out; accessing any object members may throw an exception. In Firefox 3.0+ only, script and JSONP requests cannot be cancelled by a timeout; the script will run even if it arrives after the timeout period.

Long Polling - Server

It is not in any specific language, but it would be something like this:

function handleRequest () {  

     while (!anythingHappened() || hasTimedOut()) { sleep(2); }

     return events();

} 

Here, hasTimedOut will make sure your code does not wait forever, and anythingHappened, will check if any event happend. The sleep is for releasing your thread to do other stuff while nothing happens. The events will return a dictionary of events (or any other data structure you may prefer) in JSON format (or any other you prefer).

It surely solves the problem, but, if you are concerned about scalability and perfomance as I was when researching, you might consider another solution I found.

Solution

Use sockets!

On client side, to avoid any compatibility issues, use socket.io. It tries to use socket directly, and have fallbacks to other solutions when sockets are not available.

On server side, create a server using NodeJS (example here). The client will subscribe to this channel (observer) created with the server. Whenever a notification has to be sent, it is published in this channel and the subscriptor (client) gets notified.

If you don't like this solution, try APE (Ajax Push Engine).

Hope I helped.

Decompile an APK, modify it and then recompile it

Thanks to Chris Jester-Young I managed to make it work!

I think the way I managed to do it will work only on really simple projects:

  • With Dex2jar I obtained the Jar.
  • With jd-gui I convert my Jar back to Java files.
  • With apktool i got the android manifest and the resources files.

  • In Eclipse I create a new project with the same settings as the old one (checking all the information in the manifest file)

  • When the project is created I'm replacing all the resources and the manifest with the ones I obtained with apktool
  • I paste the java files I extracted from the Jar in the src folder (respecting the packages)
  • I modify those files with what I need
  • Everything is compiling!

/!\ be sure you removed the old apk from the device an error will be thrown stating that the apk signature is not the same as the old one!

Replace words in a string - Ruby

sentence.sub! 'Robert', 'Joe'

Won't cause an exception if the replaced word isn't in the sentence (the []= variant will).

How to replace all instances?

The above replaces only the first instance of "Robert".

To replace all instances use gsub/gsub! (ie. "global substitution"):

sentence.gsub! 'Robert', 'Joe'

The above will replace all instances of Robert with Joe.

Entity Framework Core: DbContextOptionsBuilder does not contain a definition for 'usesqlserver' and no extension method 'usesqlserver'

I had this issue, it seems that I hadn't added the required NuGet packages, although I thought I had done so, make sure to check them, one by one.

Inject service in app.config

Easiest way: $injector = angular.element(document.body).injector()

Then use that to run invoke() or get()

How can I get the behavior of GNU's readlink -f on a Mac?

Here is a portable shell function that should work in ANY Bourne comparable shell. It will resolve the relative path punctuation ".. or ." and dereference symbolic links.

If for some reason you do not have a realpath(1) command, or readlink(1) this can be aliased.

which realpath || alias realpath='real_path'

Enjoy:

real_path () {
  OIFS=$IFS
  IFS='/'
  for I in $1
  do
    # Resolve relative path punctuation.
    if [ "$I" = "." ] || [ -z "$I" ]
      then continue
    elif [ "$I" = ".." ]
      then FOO="${FOO%%/${FOO##*/}}"
           continue
      else FOO="${FOO}/${I}"
    fi

    ## Resolve symbolic links
    if [ -h "$FOO" ]
    then
    IFS=$OIFS
    set `ls -l "$FOO"`
    while shift ;
    do
      if [ "$1" = "->" ]
        then FOO=$2
             shift $#
             break
      fi
    done
    IFS='/'
    fi
  done
  IFS=$OIFS
  echo "$FOO"
}

also, just in case anybody is interested here is how to implement basename and dirname in 100% pure shell code:

## http://www.opengroup.org/onlinepubs/000095399/functions/dirname.html
# the dir name excludes the least portion behind the last slash.
dir_name () {
  echo "${1%/*}"
}

## http://www.opengroup.org/onlinepubs/000095399/functions/basename.html
# the base name excludes the greatest portion in front of the last slash.
base_name () {
  echo "${1##*/}"
}

You can find updated version of this shell code at my google site: http://sites.google.com/site/jdisnard/realpath

EDIT: This code is licensed under the terms of the 2-clause (freeBSD style) license. A copy of the license may be found by following the above hyperlink to my site.

multiple conditions for JavaScript .includes() method

That can be done by using some/every methods of Array and RegEx.

To check whether ALL of words from list(array) are present in the string:

const multiSearchAnd = (text, searchWords) => (
  searchWords.every((el) => {
    return text.match(new RegExp(el,"i"))
  })
)

multiSearchAnd("Chelsey Dietrich Engineer 2018-12-11 Hire", ["cle", "hire"]) //returns false
multiSearchAnd("Chelsey Dietrich Engineer 2018-12-11 Hire", ["che", "hire"]) //returns true

To check whether ANY of words from list(array) are present in the string:

const multiSearchOr = (text, searchWords) => (
  searchWords.some((el) => {
    return text.match(new RegExp(el,"i"))
  })
)

multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["che", "hire"]) //returns true
multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["aaa", "hire"]) //returns true
multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["che", "zzzz"]) //returns true
multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["aaa", "1111"]) //returns false

How to fill color in a cell in VBA?

You need to use cell.Text = "#N/A" instead of cell.Value = "#N/A". The error in the cell is actually just text stored in the cell.

Python - How to convert JSON File to Dataframe

jsondata = '{"0001":{"FirstName":"John","LastName":"Mark","MiddleName":"Lewis","username":"johnlewis2","password":"2910"}}'
import json
import pandas as pd
jdata = json.loads(jsondata)
df = pd.DataFrame(jdata)
print df.T

This should look like this:.

         FirstName LastName MiddleName password    username
0001      John     Mark      Lewis     2910  johnlewis2

Warning: Cannot modify header information - headers already sent by ERROR

Lines 45-47:

?>

<?php

That's sending a couple of newlines as output, so the headers are already dispatched. Just remove those 3 lines (it's all one big PHP block after all, no need to end PHP parsing and then start it again), as well as the similar block on lines 60-62, and it'll work.

Notice that the error message you got actually gives you a lot of information to help you find this yourself:

Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\speedycms\deleteclient.php:47) in C:\xampp\htdocs\speedycms\deleteclient.php on line 106

The two bolded sections tell you where the item is that sent output before the headers (line 47) and where the item is that was trying to send a header after output (line 106).