Programs & Examples On #Svn merge

Questions regarding SVN merge operations.

Can you get a Windows (AD) username in PHP?

I tried almost all of these suggestions, but they were all returning empty values. If anyone else has this issue, I found this handy function on php.net (http://php.net/manual/en/function.get-current-user.php):

get_current_user();
$username = get_current_user();
echo $username;

This was the only way I was finally able to get the user's active directory username. If none of the above answers has worked, give this a try.

How to check if a div is visible state or not?

if (!$('#singlechatpanel-1').css('display') == 'none') {
   alert('visible');
}else{
   alert('hidden');
}

HTTP response header content disposition for attachments

Try changing your Content Type (media type) to application/x-download and your Content-Disposition to: attachment;filename=" + fileName;

response.setContentType("application/x-download");
response.setHeader("Content-disposition", "attachment; filename=" + fileName);

How to join entries in a set into one string?

I think you just have it backwards.

print ", ".join(set_3)

How to remove margin space around body or clear default css styles

Go with this

body {
    padding:0px;
    margin:0px;
}

How to upload & Save Files with Desired name

use this for target path for uploading

<?php
$file_name = $_FILES["csvFile"]["name"];
$target_path = $dir = plugin_dir_path( __FILE__ )."\\upload\\". $file_name;
echo $target_path;
move_uploaded_file($_FILES["csvFile"]["tmp_name"],$target_path. $file_name);
?>

Convert a string representation of a hex dump to a byte array using Java?

The Hex class in commons-codec should do that for you.

http://commons.apache.org/codec/

import org.apache.commons.codec.binary.Hex;
...
byte[] decoded = Hex.decodeHex("00A0BF");
// 0x00 0xA0 0xBF

How to trigger a file download when clicking an HTML button or JavaScript

For me ading button instead of anchor text works really well.

<a href="file.doc"><button>Download!</button></a>

It might not be ok by most rules, but it looks pretty good.

Counting array elements in Perl

Edit: Hash versus Array

As cincodenada correctly pointed out in the comment, ysth gave a better answer: I should have answered your question with another question: "Do you really want to use a Perl array? A hash may be more appropriate."

An array allocates memory for all possible indices up to the largest used so-far. In your example, you allocate 24 cells (but use only 3). By contrast, a hash only allocates space for those fields that are actually used.

Array solution: scalar grep

Here are two possible solutions (see below for explanation):

print scalar(grep {defined $_} @a), "\n";  # prints 3
print scalar(grep $_, @a), "\n";            # prints 3

Explanation: After adding $a[23], your array really contains 24 elements --- but most of them are undefined (which also evaluates as false). You can count the number of defined elements (as done in the first solution) or the number of true elements (second solution).

What is the difference? If you set $a[10]=0, then the first solution will count it, but the second solution won't (because 0 is false but defined). If you set $a[3]=undef, none of the solutions will count it.

Hash solution (by yst)

As suggested by another solution, you can work with a hash and avoid all the problems:

$a{0}  = 1;
$a{5}  = 2;
$a{23} = 3;
print scalar(keys %a), "\n";  # prints 3

This solution counts zeros and undef values.

Error: Main method not found in class Calculate, please define the main method as: public static void main(String[] args)

From the docs

In the Java programming language, every application must contain a main method whose signature is:

public static void main(String[] args)

The modifiers public and static can be written in either order (public static or static public), but the convention is to use public static as shown above. You can name the argument anything you want, but most programmers choose "args" or "argv".

As you say:

error: missing method body, or declare abstract public static void main(String[] args); ^ this is what i got after i added it after the class name

You probably haven't declared main with a body (as ';" would suggest in your error).

You need to have main method with a body, which means you need to add { and }:

public static void main(String[] args) {


}

Add it inside your class definition.

Although sometimes error messages are not very clear, most of the time they contain enough information to point to the issue. Worst case, you can search internet for the error message. Also, documentation can be really helpful.

How to execute a command prompt command from python

From Python you can do directly using below code

import subprocess
proc = subprocess.check_output('C:\Windows\System32\cmd.exe /k %windir%\System32\\reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f' ,stderr=subprocess.STDOUT,shell=True)
    print(str(proc))

in first parameter just executed User Account setting you may customize with yours.

compareTo with primitives -> Integer / int

They're already ints. Why not just use subtraction?

compare = a - b;

Note that Integer.compareTo() doesn't necessarily return only -1, 0 or 1 either.

Setting a system environment variable from a Windows batch file?

The XP Support Tools (which can be installed from your XP CD) come with a program called setx.exe:

C:\Program Files\Support Tools>setx /?

SETX: This program is used to set values in the environment
of the machine or currently logged on user using one of three modes.

1) Command Line Mode: setx variable value [-m]
   Optional Switches:
    -m  Set value in the Machine environment. Default is User.

...
For more information and example use: SETX -i

I think Windows 7 actually comes with setx as part of a standard install.

How to create a directory in Java?

Neat and clean:

import java.io.File;

public class RevCreateDirectory {

    public void revCreateDirectory() {
        //To create single directory/folder
        File file = new File("D:\\Directory1");
        if (!file.exists()) {
            if (file.mkdir()) {
                System.out.println("Directory is created!");
            } else {
                System.out.println("Failed to create directory!");
            }
        }
        //To create multiple directories/folders
        File files = new File("D:\\Directory2\\Sub2\\Sub-Sub2");
        if (!files.exists()) {
            if (files.mkdirs()) {
                System.out.println("Multiple directories are created!");
            } else {
                System.out.println("Failed to create multiple directories!");
            }
        }

    }
}

How to search multiple columns in MySQL?

Here is a query which you can use to search for anything in from your database as a search result ,

SELECT * FROM tbl_customer 
    WHERE CustomerName LIKE '%".$search."%'
    OR Address LIKE '%".$search."%' 
    OR City LIKE '%".$search."%' 
    OR PostalCode LIKE '%".$search."%' 
    OR Country LIKE '%".$search."%'

Using this code will help you search in for multiple columns easily

What is the difference between bottom-up and top-down?

Top down and bottom up DP are two different ways of solving the same problems. Consider a memoized (top down) vs dynamic (bottom up) programming solution to computing fibonacci numbers.

fib_cache = {}

def memo_fib(n):
  global fib_cache
  if n == 0 or n == 1:
     return 1
  if n in fib_cache:
     return fib_cache[n]
  ret = memo_fib(n - 1) + memo_fib(n - 2)
  fib_cache[n] = ret
  return ret

def dp_fib(n):
   partial_answers = [1, 1]
   while len(partial_answers) <= n:
     partial_answers.append(partial_answers[-1] + partial_answers[-2])
   return partial_answers[n]

print memo_fib(5), dp_fib(5)

I personally find memoization much more natural. You can take a recursive function and memoize it by a mechanical process (first lookup answer in cache and return it if possible, otherwise compute it recursively and then before returning, you save the calculation in the cache for future use), whereas doing bottom up dynamic programming requires you to encode an order in which solutions are calculated, such that no "big problem" is computed before the smaller problem that it depends on.

How do I hide the bullets on my list for the sidebar?

You have a selector ul on line 252 which is setting list-style: square outside none (a square bullet). You'll have to change it to list-style: none or just remove the line.

If you only want to remove the bullets from that specific instance, you can use the specific selector for that list and its items as follows:

ul#groups-list.items-list { list-style: none }

When do I need a fb:app_id or fb:admins?

Including the fb:app_id tag in your HTML HEAD will allow the Facebook scraper to associate the Open Graph entity for that URL with an application. This will allow any admins of that app to view Insights about that URL and any social plugins connected with it.

The fb:admins tag is similar, but allows you to just specify each user ID that you would like to give the permission to do the above.

You can include either of these tags or both, depending on how many people you want to admin the Insights, etc. A single as fb:admins is pretty much a minimum requirement. The rest of the Open Graph tags will still be picked up when people share and like your URL, however it may cause problems in the future, so please include one of the above.

fb:admins is specified like this:
<meta property="fb:admins" content="USER_ID"/>
OR
<meta property="fb:admins" content="USER_ID,USER_ID2,USER_ID3"/>

and fb:app_id like this:
<meta property="fb:app_id" content="APPID"/>

Detecting the onload event of a window opened with window.open

var myPopup = window.open(...);
myPopup.addEventListener('load', myFunction, false);

If you care about IE, use the following as the second line instead:

myPopup[myPopup.addEventListener ? 'addEventListener' : 'attachEvent'](
  (myPopup.attachEvent ? 'on' : '') + 'load', myFunction, false
);

As you can see, supporting IE is quite cumbersome and should be avoided if possible. I mean, if you need to support IE because of your audience, by all means, do so.

How to loop through all the files in a directory in c # .net?

try below code

Directory.GetFiles(txtFolderPath.Text, "*ProfileHandler.cs",SearchOption.AllDirectories)

How to make a <div> always full screen?

Change the body element into a flex container and the div into a flex item:

_x000D_
_x000D_
body {_x000D_
  display: flex;_x000D_
  height: 100vh;_x000D_
  margin: 0;_x000D_
}_x000D_
_x000D_
div {_x000D_
  flex: 1;_x000D_
  background: tan;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

Datagridview: How to set a cell in editing mode?

Setting the CurrentCell and then calling BeginEdit(true) works well for me.

The following code shows an eventHandler for the KeyDown event that sets a cell to be editable.

My example only implements one of the required key press overrides but in theory the others should work the same. (and I'm always setting the [0][0] cell to be editable but any other cell should work)

    private void dataGridView1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Tab && dataGridView1.CurrentCell.ColumnIndex == 1)
        {
            e.Handled = true;
            DataGridViewCell cell = dataGridView1.Rows[0].Cells[0];
            dataGridView1.CurrentCell = cell;
            dataGridView1.BeginEdit(true);               
        }
    }

If you haven't found it previously, the DataGridView FAQ is a great resource, written by the program manager for the DataGridView control, which covers most of what you could want to do with the control.

Getting an option text/value with JavaScript

You can use:

var option_user_selection = element.options[ element.selectedIndex ].text

Shell script variable not empty (-z option)

Why would you use -z? To test if a string is non-empty, you typically use -n:

if test -n "$errorstatus"; then
  echo errorstatus is not empty
fi

How to convert float number to Binary?

Keep multiplying the number after decimal by 2 till it becomes 1.0:

0.25*2 = 0.50
0.50*2 = 1.00

and the result is in reverse order being .01

Why is super.super.method(); not allowed in Java?

I think Jon Skeet has the correct answer. I'd just like to add that you can access shadowed variables from superclasses of superclasses by casting this:

interface I { int x = 0; }
class T1 implements I { int x = 1; }
class T2 extends T1 { int x = 2; }
class T3 extends T2 {
        int x = 3;
        void test() {
                System.out.println("x=\t\t"          + x);
                System.out.println("super.x=\t\t"    + super.x);
                System.out.println("((T2)this).x=\t" + ((T2)this).x);
                System.out.println("((T1)this).x=\t" + ((T1)this).x);
                System.out.println("((I)this).x=\t"  + ((I)this).x);
        }
}

class Test {
        public static void main(String[] args) {
                new T3().test();
        }
}

which produces the output:

x=              3
super.x=        2
((T2)this).x=   2
((T1)this).x=   1
((I)this).x=    0

(example from the JLS)

However, this doesn't work for method calls because method calls are determined based on the runtime type of the object.

SQL subquery with COUNT help

Assuming there is a column named business:

SELECT Business, COUNT(*) FROM eventsTable GROUP BY Business

How do I change the android actionbar title and icon

You can also do as follow :

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main2)
        setSupportActionBar(toolbar)
        setTitle("Activity 2")
    }

Sending XML data using HTTP POST with PHP

you can use cURL library for posting data: http://www.php.net/curl

$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_URL, "http://websiteURL");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, "XML=".$xmlcontent."&password=".$password."&etc=etc");
$content=curl_exec($ch);

where postfield contains XML you need to send - you will need to name the postfield the API service (Clickatell I guess) expects

Send email by using codeigniter library via localhost

$insert = $this->db->insert('email_notification', $data);
                $this->session->set_flashdata("msg", "<div class='alert alert-success'> Cafe has been added Successfully.</div>");

                //require ("plugins/mailer/PHPMailerAutoload.php");
                $mail = new PHPMailer;
                $mail->SMTPOptions = array(
                    'ssl' => array(
                    'verify_peer' => false,
                    'verify_peer_name' => false,
                    'allow_self_signed' => true,
                ),
                );

                $message="
                     Your Account Has beed created successfully by Admin:
                    Username: ".$this->input->post('username')." <br><br>
                    Email: ".$this->input->post('sender_email')." <br><br>
                    Regargs<br>
                    <div class='background-color:#666;color:#fff;padding:6px;
                    text-align:center;'>
                         Bookly Admin.
                    </div>
                ";
                $mail->isSMTP(); // Set mailer to use SMTP
                $mail->Host = 'smtp.gmail.com'; // Specify main and backup SMTP servers
                $mail->SMTPAuth = true; 
                $subject = "Hello  ".$this->input->post('username');
                $mail->SMTDebug=2;
                $email = $this->input->post('sender_email'); //this email is user email
                $from_label = "Account Creation";
                $mail->Username = 'your email'; // SMTP username
                $mail->Password = 'password'; // SMTP password
                $mail->SMTPSecure = 'ssl'; // Enable TLS encryption, `ssl` also accepted
                $mail->Port = 465;
                $mail->setFrom($from_label);
                $mail->addAddress($email, 'Bookly Admin');
                $mail->isHTML(true);
                $mail->Subject = $subject;
                $mail->Body = $message;
                $mail->AltBody = 'This is the body in plain text for non-HTML mail clients';
             if($mail->send()){

                  }

How to edit default.aspx on SharePoint site without SharePoint Designer

I was able to accomplish editing the default.aspx page by:

  • Opening the site in SharePoint Designer 2013
  • Then clicking 'All Files' to view all of the files,
  • Then right-click -> Edit file in Advanced Mode.

By doing that I was able to remove the tagprefix causing a problem on my page.

Execute PHP function with onclick

Here´s an alternative with AJAX but no jQuery, just regular JavaScript:

Add this to first/main php page, where you want to call the action from, but change it from a potential a tag (hyperlink) to a button element, so it does not get clicked by any bots or malicious apps (or whatever).

<head>
<script>
  // function invoking ajax with pure javascript, no jquery required.
  function myFunction(value_myfunction) {
    var xmlhttp = new XMLHttpRequest();
    xmlhttp.onreadystatechange = function() {
      if (this.readyState == 4 && this.status == 200) {
        document.getElementById("results").innerHTML += this.responseText; 
        // note '+=', adds result to the existing paragraph, remove the '+' to replace.
      }
    };
    xmlhttp.open("GET", "ajax-php-page.php?sendValue=" + value_myfunction, true);
    xmlhttp.send();
  }

</script>
</head>

<body>

  <?php $sendingValue = "thevalue"; // value to send to ajax php page. ?> 

  <!-- using button instead of hyperlink (a) -->
  <button type="button" onclick="value_myfunction('<?php echo $sendingValue; ?>');">Click to send value</button>

  <h4>Responses from ajax-php-page.php:</h4>
  <p id="results"></p> <!-- the ajax javascript enters returned GET values here -->

</body>

When the button is clicked, onclick uses the the head´s javascript function to send $sendingValue via ajax to another php-page, like many examples before this one. The other page, ajax-php-page.php, checks for the GET value and returns with print_r:

<?php

  $incoming = $_GET['sendValue'];

  if( isset( $incoming ) ) {
    print_r("ajax-php-page.php recieved this: " . "$incoming" . "<br>");
  } else {
    print_r("The request didn´t pass correctly through the GET...");
  }

?>

The response from print_r is then returned and displayed with

document.getElementById("results").innerHTML += this.responseText;

The += populates and adds to existing html elements, removing the + just updates and replaces the existing contents of the html p element "results".

How to compare objects by multiple fields

Another option you can always consider is Apache Commons. It provides a lot of options.

import org.apache.commons.lang3.builder.CompareToBuilder;

Ex:

public int compare(Person a, Person b){

   return new CompareToBuilder()
     .append(a.getName(), b.getName())
     .append(a.getAddress(), b.getAddress())
     .toComparison();
}

How to control border height?

not bad .. but try this one ... (should works for all but ist just -webkit included)

<br>
<input type="text" style="
  background: transparent;
border-bottom: 1px solid #B5D5FF;
border-left: 1px solid;
border-right: 1px solid;
border-left-color: #B5D5FF;
border-image: -webkit-linear-gradient(top, #fff 50%, #B5D5FF 0%) 1 repeat;
">

//Feel free to edit and add all other browser..

How to remove a field completely from a MongoDB document?

To remove or delete field in MongoDB

  • For single Record

    db.getCollection('userData').update({}, {$unset: {pi: 1}})
    
  • For Multi Record

    db.getCollection('userData').update({}, {$unset: {pi: 1}}, {multi: true})
    

Best practice to run Linux service as a different user

  • Some daemons (e.g. apache) do this by themselves by calling setuid()
  • You could use the setuid-file flag to run the process as a different user.
  • Of course, the solution you mentioned works as well.

If you intend to write your own daemon, then I recommend calling setuid(). This way, your process can

  1. Make use of its root privileges (e.g. open log files, create pid files).
  2. Drop its root privileges at a certain point during startup.

How to use matplotlib tight layout with Figure?

Just call fig.tight_layout() as you normally would. (pyplot is just a convenience wrapper. In most cases, you only use it to quickly generate figure and axes objects and then call their methods directly.)

There shouldn't be a difference between the QtAgg backend and the default backend (or if there is, it's a bug).

E.g.

import matplotlib.pyplot as plt

#-- In your case, you'd do something more like:
# from matplotlib.figure import Figure
# fig = Figure()
#-- ...but we want to use it interactive for a quick example, so 
#--    we'll do it this way
fig, axes = plt.subplots(nrows=4, ncols=4)

for i, ax in enumerate(axes.flat, start=1):
    ax.set_title('Test Axes {}'.format(i))
    ax.set_xlabel('X axis')
    ax.set_ylabel('Y axis')

plt.show()

Before Tight Layout

enter image description here

After Tight Layout

import matplotlib.pyplot as plt

fig, axes = plt.subplots(nrows=4, ncols=4)

for i, ax in enumerate(axes.flat, start=1):
    ax.set_title('Test Axes {}'.format(i))
    ax.set_xlabel('X axis')
    ax.set_ylabel('Y axis')

fig.tight_layout()

plt.show()

enter image description here

SQL Sum Multiple rows into one

Thank you for your responses. Turns out my problem was a database issue with duplicate entries, not with my logic. A quick table sync fixed that and the SUM feature worked as expected. This is all still useful knowledge for the SUM feature and is worth reading if you are having trouble using it.

compression and decompression of string data in java

Another example of correct compression and decompression:

@Slf4j
public class GZIPCompression {
    public static byte[] compress(final String stringToCompress) {
        if (isNull(stringToCompress) || stringToCompress.length() == 0) {
            return null;
        }

        try (final ByteArrayOutputStream baos = new ByteArrayOutputStream();
            final GZIPOutputStream gzipOutput = new GZIPOutputStream(baos)) {
            gzipOutput.write(stringToCompress.getBytes(UTF_8));
            gzipOutput.finish();
            return baos.toByteArray();
        } catch (IOException e) {
            throw new UncheckedIOException("Error while compression!", e);
        }
    }

    public static String decompress(final byte[] compressed) {
        if (isNull(compressed) || compressed.length == 0) {
            return null;
        }

        try (final GZIPInputStream gzipInput = new GZIPInputStream(new ByteArrayInputStream(compressed));
             final StringWriter stringWriter = new StringWriter()) {
            IOUtils.copy(gzipInput, stringWriter, UTF_8);
            return stringWriter.toString();
        } catch (IOException e) {
            throw new UncheckedIOException("Error while decompression!", e);
        }
    }
}

Fit cell width to content

I'm not sure if I understand your question, but I'll take a stab at it:

_x000D_
_x000D_
td {
    border: 1px solid #000;
}

tr td:last-child {
    width: 1%;
    white-space: nowrap;
}
_x000D_
<table style="width: 100%;">
    <tr>
        <td class="block">this should stretch</td>
        <td class="block">this should stretch</td>
        <td class="block">this should be the content width</td>
    </tr>
</table>
_x000D_
_x000D_
_x000D_

How to access remote server with local phpMyAdmin client?

Just add below lines to your /etc/phpmyadmin/config.inc.php file in the bottom:

$i++;
$cfg['Servers'][$i]['host'] = 'HostName:port'; //provide hostname and port if other than default
$cfg['Servers'][$i]['user'] = 'userName';   //user name for your remote server
$cfg['Servers'][$i]['password'] = 'Password';  //password
$cfg['Servers'][$i]['auth_type'] = 'config';       // keep it as config

You will get Current Server: drop down with both 127.0.0.1 and one what you have provided with $cfg['Servers'][$i]['host'] can switch between the servers.

More Details: http://sforsuresh.in/access-remote-mysql-server-using-local-phpmyadmin/

Invalid application of sizeof to incomplete type with a struct

I think that the problem is that you put #ifdef instead of #ifndef at the top of your header.h file.

How to define global variable in Google Apps Script

I'm using a workaround by returning a function with an object of my global variables:

function globalVariables(){
  var variables = {
    sheetName: 'Sheet1',
    variable1: 1,
    variable2: 2
  };
  return variables;
}

function functionThatUsesVariable (){
  var sheet =   SpreadsheetApp.getActiveSpreadsheet().getSheetByName(globalVariables().sheetName);
}

Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming?

You may want to check out Eclipse CDT. It provides a C/C++ IDE that runs on multiple platforms (e.g. Windows, Linux, Mac OS X, etc.). Debugging with Eclipse CDT is comparable to using other tools such as Visual Studio.

You can check out the Eclipse CDT Debug tutorial that also includes a number of screenshots.

jQuery: outer html()

No siblings solution:

var x = $('#xxx').parent().html();
alert(x);

Universal solution:

// no cloning necessary    
var x = $('#xxx').wrapAll('<div>').parent().html(); 
alert(x);

Fiddle here: http://jsfiddle.net/ezmilhouse/Mv76a/

Best IDE for HTML5, Javascript, CSS, Jquery support with GUI building tools

Just as an FYI - "best" questions aren't the norm at SO, but I will give you a list of options, just as a service.

OK then. These two are the ones I used:

Komodo Edit

Aptana Studio 3

and then there is always Eclipse.

*UPDATE 20 March 2013 *

Well, Sublime Text 2 is the one to heavily consider. Heavily.

Convert pandas data frame to series

You can also use stack()

df= DataFrame([list(range(5))], columns = [“a{}”.format(I) for I in range(5)])

After u run df, then run:

df.stack()

You obtain your dataframe in series

Are strongly-typed functions as parameters possible in TypeScript?

In TS we can type functions in the in the following manners:

Functions types/signatures

This is used for real implementations of functions/methods it has the following syntax:

(arg1: Arg1type, arg2: Arg2type) : ReturnType

Example:

function add(x: number, y: number): number {
    return x + y;
}

class Date {
  setTime(time: number): number {
   // ...
  }

}

Function Type Literals

Function type literals are another way to declare the type of a function. They're usually applied in the function signature of a higher-order function. A higher-order function is a function which accepts functions as parameters or which returns a function. It has the following syntax:

(arg1: Arg1type, arg2: Arg2type) => ReturnType

Example:

type FunctionType1 = (x: string, y: number) => number;

class Foo {
    save(callback: (str: string) => void) {
       // ...
    }

    doStuff(callback: FunctionType1) {
       // ...
    }

}

Get the first N elements of an array?

Use array_slice()

This is an example from the PHP manual: array_slice

$input = array("a", "b", "c", "d", "e");
$output = array_slice($input, 0, 3);   // returns "a", "b", and "c"

There is only a small issue

If the array indices are meaningful to you, remember that array_slice will reset and reorder the numeric array indices. You need the preserve_keys flag set to trueto avoid this. (4th parameter, available since 5.0.2).

Example:

$output = array_slice($input, 2, 3, true);

Output:

array([3]=>'c', [4]=>'d', [5]=>'e');

Meaning of $? (dollar question mark) in shell scripts

This is the exit status of the last executed command.

For example the command true always returns a status of 0 and false always returns a status of 1:

true
echo $? # echoes 0
false
echo $? # echoes 1

From the manual: (acessible by calling man bash in your shell)

$?       Expands to the exit status of the most recently executed foreground pipeline.

By convention an exit status of 0 means success, and non-zero return status means failure. Learn more about exit statuses on wikipedia.

There are other special variables like this, as you can see on this online manual: https://www.gnu.org/s/bash/manual/bash.html#Special-Parameters

android.widget.Switch - on/off event listener?

For those using Kotlin, you can set a listener for a switch (in this case having the ID mySwitch) as follows:

    mySwitch.setOnCheckedChangeListener { _, isChecked ->
         // do whatever you need to do when the switch is toggled here
    }

isChecked is true if the switch is currently checked (ON), and false otherwise.

How to execute UNION without sorting? (SQL)

I assume your tables are table1 and table2 respectively, and your solution is;

(select * from table1 MINUS select * from table2)
UNION ALL
(select * from table2 MINUS select * from table1)

jQuery select child element by class with unknown path

$('#thisElement').find('.classToSelect') will find any descendents of #thisElement with class classToSelect.

What is the difference between response.sendRedirect() and request.getRequestDispatcher().forward(request,response)

Redirect and Request dispatcher are two different methods to move form one page to another. if we are using redirect to a new page actually a new request is happening from the client side itself to the new page. so we can see the change in the URL. Since redirection is a new request the old request values are not available here.

Getting the document object of an iframe

For even more robustness:

function getIframeWindow(iframe_object) {
  var doc;

  if (iframe_object.contentWindow) {
    return iframe_object.contentWindow;
  }

  if (iframe_object.window) {
    return iframe_object.window;
  } 

  if (!doc && iframe_object.contentDocument) {
    doc = iframe_object.contentDocument;
  } 

  if (!doc && iframe_object.document) {
    doc = iframe_object.document;
  }

  if (doc && doc.defaultView) {
   return doc.defaultView;
  }

  if (doc && doc.parentWindow) {
    return doc.parentWindow;
  }

  return undefined;
}

and

...
var el = document.getElementById('targetFrame');

var frame_win = getIframeWindow(el);

if (frame_win) {
  frame_win.targetFunction();
  ...
}
...

How do I specify unique constraint for multiple columns in MySQL?

I do it like this:

CREATE UNIQUE INDEX index_name ON TableName (Column1, Column2, Column3);

My convention for a unique index_name is TableName_Column1_Column2_Column3_uindex.

What are .tpl files? PHP, web design

Templates. I think that is Smarty syntax.

Check if TextBox is empty and return MessageBox?

Adding on to what @tjg184 said, you could do something like...

if (String.IsNullOrEmpty(MaterialTextBox.Text.Trim())) 

...

How do you stretch an image to fill a <div> while keeping the image's aspect-ratio?

I had similar issue. I resolved it with just CSS.

Basically Object-fit: cover helps you achieve the task of maintaining the aspect ratio while positioning an image inside a div.

But the problem was Object-fit: cover was not working in IE and it was taking 100% width and 100% height and aspect ratio was distorted. In other words image zooming effect wasn't there which I was seeing in chrome.

The approach I took was to position the image inside the container with absolute and then place it right at the centre using the combination:

position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);

Once it is in the centre, I give to the image,

// For vertical blocks (i.e., where height is greater than width)
height: 100%;
width: auto;

// For Horizontal blocks (i.e., where width is greater than height)
height: auto;
width: 100%;

This makes the image get the effect of Object-fit:cover.


Here is a demonstration of the above logic.

https://jsfiddle.net/furqan_694/s3xLe1gp/

This logic works in all browsers.

Adding a HTTP header to the Angular HttpClient doesn't send the header, why?

In my legacy app Array.from of prototype js was conflicting with angular's Array.from that was causing this problem. I resolved it by saving angular's Array.from version and reassigning it after prototype load.

How do I print colored output to the terminal in Python?

Compared to the methods listed here, I prefer the method that comes with the system. Here, I provide a better method without third-party libraries.

class colors: # You may need to change color settings
    RED = '\033[31m'
    ENDC = '\033[m'
    GREEN = '\033[32m'
    YELLOW = '\033[33m'
    BLUE = '\033[34m'

print(colors.RED + "something you want to print in red color" + colors.ENDC)
print(colors.GREEN + "something you want to print in green color" + colors.ENDC)
print("something you want to print in system default color")

More color code , ref to : Printing Colored Text in Python

Enjoy yourself!

Custom seekbar (thumb size, color and background)

Android custom SeekBar - custom track or progress, shape, size, background and thumb and for other seekbar customization see http://www.zoftino.com/android-seekbar-and-custom-seekbar-examples

Custom Track drawable

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/background"
        android:gravity="center_vertical|fill_horizontal">
        <shape android:shape="rectangle"
            android:tint="#ffd600">
            <corners android:radius="8dp"/>
            <size android:height="30dp" />
            <solid android:color="#ffd600" />
        </shape>
    </item>
    <item android:id="@android:id/progress"
        android:gravity="center_vertical|fill_horizontal">
        <scale android:scaleWidth="100%">
            <selector>
                <item android:state_enabled="false"
                    android:drawable="@android:color/transparent" />
                <item>
                    <shape android:shape="rectangle"
                        android:tint="#f50057">
                        <corners android:radius="8dp"/>
                        <size android:height="30dp" />
                        <solid android:color="#f50057" />
                    </shape>
                </item>
            </selector>
        </scale>
    </item>
</layer-list>

Custom thumb drawable

?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"
    android:thickness="4dp"
    android:useLevel="false"
    android:tint="#ad1457">
    <solid
        android:color="#ad1457" />
    <size
        android:width="32dp"
        android:height="32dp" />
</shape>

Output

enter image description here

Default values and initialization in Java

These are the main factors involved:

  1. member variable (default OK)
  2. static variable (default OK)
  3. final member variable (not initialized, must set on constructor)
  4. final static variable (not initialized, must set on a static block {})
  5. local variable (not initialized)

Note 1: you must initialize final member variables on every implemented constructor!

Note 2: you must initialize final member variables inside the block of the constructor itself, not calling another method that initializes them. For instance, this is not valid:

private final int memberVar;

public Foo() {
    // Invalid initialization of a final member
    init();
}

private void init() {
    memberVar = 10;
}

Note 3: arrays are Objects in Java, even if they store primitives.

Note 4: when you initialize an array, all of its items are set to default, independently of being a member or a local array.

I am attaching a code example, presenting the aforementioned cases:

public class Foo {
    // Static and member variables are initialized to default values

    // Primitives
    private int a; // Default 0
    private static int b; // Default 0

    // Objects
    private Object c; // Default NULL
    private static Object d; // Default NULL

    // Arrays (note: they are objects too, even if they store primitives)
    private int[] e; // Default NULL
    private static int[] f; // Default NULL

    // What if declared as final?

    // Primitives
    private final int g; // Not initialized. MUST set in the constructor
    private final static int h; // Not initialized. MUST set in a static {}

    // Objects
    private final Object i; // Not initialized. MUST set in constructor
    private final static Object j; // Not initialized. MUST set in a static {}

    // Arrays
    private final int[] k; // Not initialized. MUST set in constructor
    private final static int[] l; // Not initialized. MUST set in a static {}

    // Initialize final statics
    static {
        h = 5;
        j = new Object();
        l = new int[5]; // Elements of l are initialized to 0
    }

    // Initialize final member variables
    public Foo() {
        g = 10;
        i = new Object();
        k = new int[10]; // Elements of k are initialized to 0
    }

    // A second example constructor
    // You have to initialize final member variables to every constructor!
    public Foo(boolean aBoolean) {
        g = 15;
        i = new Object();
        k = new int[15]; // Elements of k are initialized to 0
    }

    public static void main(String[] args) {
        // Local variables are not initialized
        int m; // Not initialized
        Object n; // Not initialized
        int[] o; // Not initialized

        // We must initialize them before use
        m = 20;
        n = new Object();
        o = new int[20]; // Elements of o are initialized to 0
    }
}

Toolbar navigation icon never set

I used the method below which really is a conundrum of all the ones above. I also found that onOptionsItemSelected is never activated.

    mDrawerToggle.setDrawerIndicatorEnabled(false);
    getSupportActionBar().setHomeButtonEnabled(true);

    Toolbar toolbar = (Toolbar) findViewById(R.id.tool_bar);
    if (toolbar != null) {
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onBackPressed();
            }
        });
    }

Windows batch script to move files

You can try this:

:backup move C:\FilesToBeBackedUp\*.* E:\BackupPlace\ timeout 36000 goto backup

If that doesn't work try to replace "timeout" with sleep. Ik this post is over a year old, just helping anyone with the same problem.

How to handle the click event in Listview in android?

First, the class must implements the click listenener :

implements OnItemClickListener

Then set a listener to the ListView

yourList.setOnItemclickListener(this);

And finally, create the clic method:

@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Toast.makeText(MainActivity.this, "You Clicked at ",   
 Toast.LENGTH_SHORT).show();
}

Size of character ('a') in C/C++

In C language, character literal is not a char type. C considers character literal as integer. So, there is no difference between sizeof('a') and sizeof(1).

So, the sizeof character literal is equal to sizeof integer in C.

In C++ language, character literal is type of char. The cppreference say's:

1) narrow character literal or ordinary character literal, e.g. 'a' or '\n' or '\13'. Such literal has type char and the value equal to the representation of c-char in the execution character set. If c-char is not representable as a single byte in the execution character set, the literal has type int and implementation-defined value.

So, in C++ character literal is a type of char. so, size of character literal in C++ is one byte.

Alos, In your programs, you have used wrong format specifier for sizeof operator.

C11 §7.21.6.1 (P9) :

If a conversion specification is invalid, the behavior is undefined.275) If any argument is not the correct type for the corresponding conversion specification, the behavior is undefined.

So, you should use %zu format specifier instead of %d, otherwise it is undefined behaviour in C.

What does the C++ standard state the size of int, long type to be?

As others have answered, the "standards" all leave most of the details as "implementation defined" and only state that type "char" is at leat "char_bis" wide, and that "char <= short <= int <= long <= long long" (float and double are pretty much consistent with the IEEE floating point standards, and long double is typically same as double--but may be larger on more current implementations).

Part of the reasons for not having very specific and exact values is because languages like C/C++ were designed to be portable to a large number of hardware platforms--Including computer systems in which the "char" word-size may be 4-bits or 7-bits, or even some value other than the "8-/16-/32-/64-bit" computers the average home computer user is exposed to. (Word-size here meaning how many bits wide the system normally operates on--Again, it's not always 8-bits as home computer users may expect.)

If you really need a object (in the sense of a series of bits representing an integral value) of a specific number of bits, most compilers have some method of specifying that; But it's generally not portable, even between compilers made by the ame company but for different platforms. Some standards and practices (especially limits.h and the like) are common enough that most compilers will have support for determining at the best-fit type for a specific range of values, but not the number of bits used. (That is, if you know you need to hold values between 0 and 127, you can determine that your compiler supports an "int8" type of 8-bits which will be large enought to hold the full range desired, but not something like an "int7" type which would be an exact match for 7-bits.)

Note: Many Un*x source packages used "./configure" script which will probe the compiler/system's capabilities and output a suitable Makefile and config.h. You might examine some of these scripts to see how they work and how they probe the comiler/system capabilities, and follow their lead.

How to print the number of characters in each line of a text file

Try this:

while read line    
do    
    echo -e |wc -m      
done <abc.txt    

PHP Echo a large block of text

To expand on @hookedonwinter's answer, here's an alternate (cleaner, in my opinion) syntax:

<?php if (is_single()): ?>
    <p>This will be shown if "is_single()" is true.</p>
<?php else: ?>
    <p>This will be shown otherwise.</p>
<?php endif; ?>

Pandas - Plotting a stacked Bar Chart

Are you getting errors, or just not sure where to start?

%pylab inline
import pandas as pd
import matplotlib.pyplot as plt

df2 = df.groupby(['Name', 'Abuse/NFF'])['Name'].count().unstack('Abuse/NFF').fillna(0)
df2[['abuse','nff']].plot(kind='bar', stacked=True)

stacked bar plot

How do I check if an integer is even or odd?

[Joke mode="on"]

public enum Evenness
{
  Unknown = 0,
  Even = 1,
  Odd = 2
}

public static Evenness AnalyzeEvenness(object o)
{

  if (o == null)
    return Evenness.Unknown;

  string foo = o.ToString();

  if (String.IsNullOrEmpty(foo))
    return Evenness.Unknown;

  char bar = foo[foo.Length - 1];

  switch (bar)
  {
     case '0':
     case '2':
     case '4':
     case '6':
     case '8':
       return Evenness.Even;
     case '1':
     case '3':
     case '5':
     case '7':
     case '9':
       return Evenness.Odd;
     default:
       return Evenness.Unknown;
  }
}

[Joke mode="off"]

EDIT: Added confusing values to the enum.

Virtual member call in a constructor

The rules of C# are very different from that of Java and C++.

When you are in the constructor for some object in C#, that object exists in a fully initialized (just not "constructed") form, as its fully derived type.

namespace Demo
{
    class A 
    {
      public A()
      {
        System.Console.WriteLine("This is a {0},", this.GetType());
      }
    }

    class B : A
    {      
    }

    // . . .

    B b = new B(); // Output: "This is a Demo.B"
}

This means that if you call a virtual function from the constructor of A, it will resolve to any override in B, if one is provided.

Even if you intentionally set up A and B like this, fully understanding the behavior of the system, you could be in for a shock later. Say you called virtual functions in B's constructor, "knowing" they would be handled by B or A as appropriate. Then time passes, and someone else decides they need to define C, and override some of the virtual functions there. All of a sudden B's constructor ends up calling code in C, which could lead to quite surprising behavior.

It is probably a good idea to avoid virtual functions in constructors anyway, since the rules are so different between C#, C++, and Java. Your programmers may not know what to expect!

"Please provide a valid cache path" error in laravel

Try the following:

create these folders under storage/framework:

  • sessions
  • views
  • cache

Now it should work

Closing Bootstrap modal onclick

Close the modal with universal $().hide() method:

$('#product-options').hide();

Writing numerical values on the plot with Matplotlib

You can use the annotate command to place text annotations at any x and y values you want. To place them exactly at the data points you could do this

import numpy
from matplotlib import pyplot

x = numpy.arange(10)
y = numpy.array([5,3,4,2,7,5,4,6,3,2])

fig = pyplot.figure()
ax = fig.add_subplot(111)
ax.set_ylim(0,10)
pyplot.plot(x,y)
for i,j in zip(x,y):
    ax.annotate(str(j),xy=(i,j))

pyplot.show()

If you want the annotations offset a little, you could change the annotate line to something like

ax.annotate(str(j),xy=(i,j+0.5))

Facebook API: Get fans of / people who like a page

This page https://developers.facebook.com/docs/reference/fql/like/ wrote, you can't get fan list.

"The Post, Video, Note, Link, Photo and Album Graph API objects contain an equivalent connection called likes."

NOTE: fql like query is deprecated

Why does IE9 switch to compatibility mode on my website?

As an aside on more modern websites, if you are using conditional statements on your html tag as per boilerplate, this will for some reason cause ie9 to default to compatibility mode. The fix here is to move your conditional statements off the html tag and add them to the body tag, in other words out of the head section. That way you can still use those classes in your style sheet to target older browsers.

"psql: could not connect to server: Connection refused" Error when connecting to remote database

Mine was quite straightforward if you are on a Mac try:

brew install postgres

This will tell you if you have it already install and what version or install the latest version for you if not then run

brew upgrade postgresql

This will make sure you have the latest version installed then finally

brew services start postgresql

This will start the service again. I hope this helps someone.

What is the difference between the GNU Makefile variable assignments =, ?=, := and +=?

The most upvoted answer can be improved.

Let me refer to GNU Make manual "Setting variables" and "Flavors", and add some comments.

Recursively expanded variables

The value you specify is installed verbatim; if it contains references to other variables, these references are expanded whenever this variable is substituted (in the course of expanding some other string). When this happens, it is called recursive expansion.

foo = $(bar)

The catch: foo will be expanded to the value of $(bar) each time foo is evaluated, possibly resulting in different values. Surely you cannot call it "lazy"! This can surprise you if executed on midnight:

# This variable is haunted!
WHEN = $(shell date -I)

something:
    touch $(WHEN).flag

# If this is executed on 00:00:00:000, $(WHEN) will have a different value!
something-else-later: something
    test -f $(WHEN).flag || echo "Boo!"

Simply expanded variable

VARIABLE := value
VARIABLE ::= value

Variables defined with ‘:=’ or ‘::=’ are simply expanded variables.

Simply expanded variables are defined by lines using ‘:=’ or ‘::=’ [...]. Both forms are equivalent in GNU make; however only the ‘::=’ form is described by the POSIX standard [...] 2012.

The value of a simply expanded variable is scanned once and for all, expanding any references to other variables and functions, when the variable is defined.

Not much to add. It's evaluated immediately, including recursive expansion of, well, recursively expanded variables.

The catch: If VARIABLE refers to ANOTHER_VARIABLE:

VARIABLE := $(ANOTHER_VARIABLE)-yohoho

and ANOTHER_VARIABLE is not defined before this assignment, ANOTHER_VARIABLE will expand to an empty value.

Assign if not set

FOO ?= bar

is equivalent to

ifeq ($(origin FOO), undefined)
FOO = bar
endif

where $(origin FOO) equals to undefined only if the variable was not set at all.

The catch: if FOO was set to an empty string, either in makefiles, shell environment, or command line overrides, it will not be assigned bar.

Appending

VAR += bar

Appending:

When the variable in question has not been defined before, ‘+=’ acts just like normal ‘=’: it defines a recursively-expanded variable. However, when there is a previous definition, exactly what ‘+=’ does depends on what flavor of variable you defined originally.

So, this will print foo bar:

VAR = foo
# ... a mile of code
VAR += $(BAR)
BAR = bar
$(info $(VAR))

but this will print foo:

VAR := foo
# ... a mile of code
VAR += $(BAR)
BAR = bar
$(info $(VAR))

The catch is that += behaves differently depending on what type of variable VAR was assigned before.

Multiline values

The syntax to assign multiline value to a variable is:

define VAR_NAME :=
line
line
endef

or

define VAR_NAME =
line
line
endef

Assignment operator can be omitted, then it creates a recursively-expanded variable.

define VAR_NAME
line
line
endef

The last newline before endef is removed.

Bonus: the shell assignment operator ‘!=’

 HASH != printf '\043'

is the same as

HASH := $(shell printf '\043')

Don't use it. $(shell) call is more readable, and the usage of both in a makefiles is highly discouraged. At least, $(shell) follows Joel's advice and makes wrong code look obviously wrong.

Extension exists but uuid_generate_v4 fails

if you do it from unix command (apart from PGAdmin) dont forget to pass the DB as a parameter. otherwise this extension will not be enabled when executing requests on this DB

psql -d -c "create EXTENSION pgcrypto;"

ASP MVC in IIS 7 results in: HTTP Error 403.14 - Forbidden

Check your Global.asax file. In my case, it was empty.

Does WhatsApp offer an open API?

  1. is the correct answer. WhatsApp is intentionally a closed system without an API for external access.

There were several projects available that reverse engineered the WhatsApp webservice interfaces. However, to my knowledge all of them are now discontinued/defunct due to legal action against them from WhatsApp.

For mobile phone applications there is a limited URL-Scheme-API available on IPhone and Android (Android-intent possible as well).

Postgres where clause compare timestamp

Assuming you actually mean timestamp because there is no datetime in Postgres

Cast the timestamp column to a date, that will remove the time part:

select *
from the_table
where the_timestamp_column::date = date '2015-07-15';

This will return all rows from July, 15th.

Note that the above will not use an index on the_timestamp_column. If performance is critical, you need to either create an index on that expression or use a range condition:

select *
from the_table
where the_timestamp_column >= timestamp '2015-07-15 00:00:00'
  and the_timestamp_column < timestamp '2015-07-16 00:00:00';

Is there a cross-browser onload event when clicking the back button?

jQuery's ready event was created for just this sort of issue. You may want to dig into the implementation to see what is going on under the covers.

What programming languages can one use to develop iPhone, iPod Touch and iPad (iOS) applications?

objective-c is the primary language used.

i believe there is a mono touch framework that can be used with c#

Adobe also is working in some tools, one is this iPhone Packager which can utilize actionscript code

Determine the line of code that causes a segmentation fault?

You could also use a core dump and then examine it with gdb. To get useful information you also need to compile with the -g flag.

Whenever you get the message:

 Segmentation fault (core dumped)

a core file is written into your current directory. And you can examine it with the command

 gdb your_program core_file

The file contains the state of the memory when the program crashed. A core dump can be useful during the deployment of your software.

Make sure your system doesn't set the core dump file size to zero. You can set it to unlimited with:

ulimit -c unlimited

Careful though! that core dumps can become huge.

Simple logical operators in Bash

What you've written actually almost works (it would work if all the variables were numbers), but it's not an idiomatic way at all.

  • (…) parentheses indicate a subshell. What's inside them isn't an expression like in many other languages. It's a list of commands (just like outside parentheses). These commands are executed in a separate subprocess, so any redirection, assignment, etc. performed inside the parentheses has no effect outside the parentheses.
    • With a leading dollar sign, $(…) is a command substitution: there is a command inside the parentheses, and the output from the command is used as part of the command line (after extra expansions unless the substitution is between double quotes, but that's another story).
  • { … } braces are like parentheses in that they group commands, but they only influence parsing, not grouping. The program x=2; { x=4; }; echo $x prints 4, whereas x=2; (x=4); echo $x prints 2. (Also braces require spaces around them and a semicolon before closing, whereas parentheses don't. That's just a syntax quirk.)
    • With a leading dollar sign, ${VAR} is a parameter expansion, expanding to the value of a variable, with possible extra transformations.
  • ((…)) double parentheses surround an arithmetic instruction, that is, a computation on integers, with a syntax resembling other programming languages. This syntax is mostly used for assignments and in conditionals.
    • The same syntax is used in arithmetic expressions $((…)), which expand to the integer value of the expression.
  • [[ … ]] double brackets surround conditional expressions. Conditional expressions are mostly built on operators such as -n $variable to test if a variable is empty and -e $file to test if a file exists. There are also string equality operators: "$string1" == "$string2" (beware that the right-hand side is a pattern, e.g. [[ $foo == a* ]] tests if $foo starts with a while [[ $foo == "a*" ]] tests if $foo is exactly a*), and the familiar !, && and || operators for negation, conjunction and disjunction as well as parentheses for grouping. Note that you need a space around each operator (e.g. [[ "$x" == "$y" ]], not [[ "$x"=="$y" ]]), and a space or a character like ; both inside and outside the brackets (e.g. [[ -n $foo ]], not [[-n $foo]]).
  • [ … ] single brackets are an alternate form of conditional expressions with more quirks (but older and more portable). Don't write any for now; start worrying about them when you find scripts that contain them.

This is the idiomatic way to write your test in bash:

if [[ $varA == 1 && ($varB == "t1" || $varC == "t2") ]]; then

If you need portability to other shells, this would be the way (note the additional quoting and the separate sets of brackets around each individual test, and the use of the traditional = operator rather than the ksh/bash/zsh == variant):

if [ "$varA" = 1 ] && { [ "$varB" = "t1" ] || [ "$varC" = "t2" ]; }; then

How to convert an array of strings to an array of floats in numpy?

If you have (or create) a single string, you can use np.fromstring:

import numpy as np
x = ["1.1", "2.2", "3.2"]
x = ','.join(x)
x = np.fromstring( x, dtype=np.float, sep=',' )

Note, x = ','.join(x) transforms the x array to string '1.1, 2.2, 3.2'. If you read a line from a txt file, each line will be already a string.

HAProxy redirecting http to https (ssl)

I found this to be the biggest help:

Use HAProxy 1.5 or newer, and simply add the following line to the frontend config:

redirect scheme https code 301 if !{ ssl_fc }

Javascript use variable as object name

I think Shaz's answer for local variables is hard to understand, though it works for non-recursive functions. Here's another way that I think it's clearer (but it's still his idea, exact same behavior). It's also not accessing the local variables dynamically, just the property of the local variable.

Essentially, it's using a global variable (attached to the function object)

// Here's  a version of it that is more straight forward.
function doIt() {
    doIt.objname = {};
    var someObject = "objname";
    doIt[someObject].value = "value";    
    console.log(doIt.objname);
})();

Which is essentially the same thing as creating a global to store the variable, so you can access it as a property. Creating a global to do this is such a hack.

Here's a cleaner hack that doesn't create global variables, it uses a local variable instead.

function doIt() {
  var scope = {
     MyProp: "Hello"
  };
  var name = "MyProp";
  console.log(scope[name]);
}

See Javascript: interpret string as object reference?

Get the filePath from Filename using Java

You may use:

FileSystems.getDefault().getPath(new String()).toAbsolutePath();

or

FileSystems.getDefault().getPath(new String("./")).toAbsolutePath().getParent()

This will give you the root folder path without using the name of the file. You can then drill down to where you want to go.

Example: /src/main/java...

Controlling execution order of unit tests in Visual Studio

Since you've already mentioned the Ordered Test functionality that the Visual Studio testing framework supplies, I'll ignore that. You also seem to be aware that what you're trying to accomplish in order to test this Static Class is a "bad idea", so I'll ignore that to.

Instead, lets focus on how you might actually be able to guarantee that your tests are executed in the order you want. One option (as supplied by @gaog) is "one test method, many test functions", calling your test functions in the order that you want from within a single function marked with the TestMethod attribute. This is the simplest way, and the only disadvantage is that the first test function to fail will prevent any of the remaining test functions from executing.

With your description of the situation, this is the solution I would suggest you use.

If the bolded part is a problem for you, you can accomplish an ordered execution of isolated tests by leveraging the in built data driven test functionality. Its more complicated and feels a bit dirty, but it gets the job done.

In short, you define a data source (like a CSV file, or a database table) that controls the order in which you need to run your tests, and names of the functions that actually contain the test functionality. You then hook that data source into a data driven test, use the sequential read option, and execute your functions, in the order you want, as individual tests.

[TestClass]
public class OrderedTests
{
    public TestContext TestContext { get; set; }

    private const string _OrderedTestFilename = "TestList.csv";

    [TestMethod]
    [DeploymentItem(_OrderedTestFilename)]
    [DataSource("Microsoft.VisualStudio.TestTools.DataSource.CSV", _OrderedTestFilename, _OrderedTestFilename, DataAccessMethod.Sequential)]
    public void OrderedTests()
    {
        var methodName = (string)TestContext.DataRow[0];
        var method = GetType().GetMethod(methodName);
        method.Invoke(this, new object[] { });
    }

    public void Method_01()
    {
        Assert.IsTrue(true);
    }

    public void Method_02()
    {
        Assert.IsTrue(false);
    }

    public void Method_03()
    {
        Assert.IsTrue(true);
    }
}

In my example, I have a supporting file called TestList.csv, which gets copied to output. It looks like this:

TestName
Method_01
Method_02
Method_03

Your tests will be executed in the order that you specified, and in normal test isolation (i.e. if one fails, the rest still get executed, but sharing static classes).

The above is really only the basic idea, if I were to use it in production I would generate the test function names and their order dynamically before the test is run. Perhaps by leveraging PriorityAttribute you found and some simple reflection code to extract the test methods in the class and order them appropriately, then write that order to the data source.

ASP.NET MVC - Attaching an entity of type 'MODELNAME' failed because another entity of the same type already has the same primary key value

I have added this answer only because the problem is explained based on more complex data pattern and I found it hard to understand here.

I created a fairly simple application. This error occurred inside Edit POST action. The action accepted ViewModel as an input parameter. The reason for using the ViewModel was to make some calculation before the record was saved.

Once the action passed through validation such as if(ModelState.IsValid), my wrongdoing was to project values from ViewModel into a completely new instance of Entity. I thought I'd have to create a new instance to store updated data and then saved such instance.

What I had realised later was that I had to read the record from database:

Student student = db.Students.Find(s => s.StudentID == ViewModel.StudentID);

and updated this object. Everything works now.

Get type of a generic parameter in Java with reflection

I noticed that many people lean towards the getGenericSuperclass() solution:

class RootGeneric<T> {
  public Class<T> persistentClass = (Class<T>)
    ((ParameterizedType)getClass().getGenericSuperclass())
      .getActualTypeArguments()[0];
}

However, this solution is error prone. It will not work properly if there are generics in the descendants. Consider this:

class Foo<S> extends RootGeneric<Integer> {}

class Bar extends Foo<Double> {}

Which type will Bar.persistentClass have? Class<Integer>? Nope, it will be Class<Double>. This will happen due to getClass() always returns the top most class, which is Bar in this case, and its generic super class is Foo<Double>. Hence, the argument type will be Double.

If you need a reliable solution which doesn't fail I can suggest two.

  1. Use Guava. It has a class that was made exactly for this purpose: com.google.common.reflect.TypeToken. It handles all the corner cases just fine and offers some more nice functionality. The downside is an extra dependency. Given you've used this class, your code would look simple and clear, like this:
class RootGeneric<T> {
  @SuppressWarnings("unchecked")
  public final Class<T> persistentClass = (Class<T>) (new TypeToken<T>(getClass()) {}.getType());
}
  1. Use the custom method below. It implements a significantly simplified logic similar to the Guava class, mentioned above. However, I'd not guarantee it's error prone. It does solve the problem with the generic descendants though.
abstract class RootGeneric<T> {
  @SuppressWarnings("unchecked")
  private Class<T> getTypeOfT() {
    Class<T> type = null;
    Class<?> iter = getClass();
    while (iter.getSuperclass() != null) {
      Class<?> next = iter.getSuperclass();
      if (next != null && next.isAssignableFrom(RootGeneric.class)) {
        type =
            (Class<T>)
                ((ParameterizedType) iter.getGenericSuperclass()).getActualTypeArguments()[0];
        break;
      }
      iter = next;
    }
    if (type == null) {
      throw new ClassCastException("Cannot determine type of T");
    }
    return type;
  }
}

Updating records codeigniter

How to update in codeignitor?

whenever you want to update same status with multiple rows you use where_in insteam of where or if you want to change only single record can use where.

below is my code

$conditionArray = array(1, 3, 4, 6);
$this->db->where_in("ip_id", $conditionArray);
$this->db->update($this->table, array("status" => 'active'));

its working perfect.

How to Export-CSV of Active Directory Objects?

From a Windows Server OS execute the following command for a dump of the entire Active Director:

csvde -f test.csv

This command is very broad and will give you more than necessary information. To constrain the records to only user records, you would instead want:

csvde -f test.csv -r objectClass=user 

You can further restrict the command to give you only the fields you need relevant to the search requested such as:

csvde -f test.csv -r objectClass=user -l DN, sAMAccountName, department, memberOf

If you have an Exchange server and each user associated with a live person has a mailbox (as opposed to generic accounts for kiosk / lab workstations) you can use mailNickname in place of sAMAccountName.

Disabled form fields not submitting data

We can also use the readonly only with below attributes -

readonly onclick='return false;'

This is because if we will only use the readonly then radio buttons will be editable. To avoid this situation we can use readonly with above combination. It will restrict the editing and element's values will also passed during form submission.

How to set specific window (frame) size in java swing?

Well, you are using both frame.setSize() and frame.pack().

You should use one of them at one time.

Using setSize() you can give the size of frame you want but if you use pack(), it will automatically change the size of the frames according to the size of components in it. It will not consider the size you have mentioned earlier.

Try removing frame.pack() from your code or putting it before setting size and then run it.

Entity Framework Core: A second operation started on this context before a previous operation completed

Entity Framework Core does not support multiple parallel operations being run on the same DbContext instance. This includes both parallel execution of async queries and any explicit concurrent use from multiple threads. Therefore, always await async calls immediately, or use separate DbContext instances for operations that execute in parallel.

How to clear the JTextField by clicking JButton

Looking for EventHandling, ActionListener?

or code?

JButton b = new JButton("Clear");
b.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
        textfield.setText("");
        //textfield.setText(null); //or use this
    }
});

Also See
How to Use Buttons

MySQL string replace

UPDATE your_table
SET your_field = REPLACE(your_field, 'articles/updates/', 'articles/news/')
WHERE your_field LIKE '%articles/updates/%'

Now rows that were like

http://www.example.com/articles/updates/43

will be

http://www.example.com/articles/news/43

http://www.electrictoolbox.com/mysql-find-replace-text/

Redefine tab as 4 spaces

Put your desired settings in the ~/.vimrc file -- See below for some guidelines and best practices.

There are four main ways to use tabs in Vim:

  1. Always keep 'tabstop' at 8, set 'softtabstop' and 'shiftwidth' to 4 (or 3 or whatever you prefer) and use 'noexpandtab'. Then Vim will use a mix of tabs and spaces, but typing and will behave like a tab appears every 4 (or 3) characters.

    Note: Setting 'tabstop' to any other value than 8 can make your file appear wrong in many places (e.g., when printing it).

  2. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use 'expandtab'. This way you will always insert spaces. The formatting will never be messed up when 'tabstop' is changed.

  3. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use a |modeline| to set these values when editing the file again. Only works when using Vim to edit the file.

  4. Always set 'tabstop' and 'shiftwidth' to the same value, and 'noexpandtab'. This should then work (for initial indents only) for any tabstop setting that people use. It might be nice to have tabs after the first non-blank inserted as spaces if you do this though. Otherwise aligned comments will be wrong when 'tabstop' ischanged.

Source:

How to print all information from an HTTP request to the screen, in PHP

Putting together answers from Peter Bailey and Cmyker you get something like:

<?php
foreach ($_SERVER as $key => $value) {
    if (strpos($key, 'HTTP_') === 0) {
        $chunks = explode('_', $key);
        $header = '';
        for ($i = 1; $y = sizeof($chunks) - 1, $i < $y; $i++) {
            $header .= ucfirst(strtolower($chunks[$i])).'-';
        }
        $header .= ucfirst(strtolower($chunks[$i])).': '.$value;
        echo $header."\n";
    }
}
$body = file_get_contents('php://input');
if ($body != '') {
  print("\n$body\n\n");
}
?>

which works with the php -S built-in webserver, which is quite a handy feature of PHP.

Run Jquery function on window events: load, resize, and scroll?

You can bind listeners to one common functions -

$(window).bind("load resize scroll",function(e){
  // do stuff
});

Or another way -

$(window).bind({
     load:function(){

     },
     resize:function(){

     },
     scroll:function(){

    }
});

Alternatively, instead of using .bind() you can use .on() as bind directly maps to on(). And maybe .bind() won't be there in future jquery versions.

$(window).on({
     load:function(){

     },
     resize:function(){

     },
     scroll:function(){

    }
});

What is the difference between the operating system and the kernel?

Basically the Kernel is the interface between hardware (devices which are available in Computer) and Application software is like MS Office, Visual Studio, etc.

If I answer "what is an OS?" then the answer could be the same. Hence the kernel is the part & core of the OS.

The very sensitive tasks of an OS like memory management, I/O management, process management are taken care of by the kernel only.

So the ultimate difference is:

  1. Kernel is responsible for Hardware level interactions at some specific range. But the OS is like hardware level interaction with full scope of computer.
  2. Kernel triggers SystemCalls to tell the OS that this resource is available at this point of time. The OS is responsible to handle those system calls in order to utilize the resource.

How to select all instances of a variable and edit variable name in Sublime

To me, this is the biggest mistake in Sublime. Alt+F3 is hard to reach/remember, and Ctrl+Shift+G makes no sense considering Ctrl+D is "add next instance to selection".

Add this to your User Key Bindings (Preferences > Key Bindings):

{ "keys": ["ctrl+shift+d"], "command": "find_all_under" },

Now you can highlight something, press Ctrl+Shift+D, and it will add every other instance in the file to the selection.

Is there a way to ignore a single FindBugs warning?

I'm going to leave this one here: https://stackoverflow.com/a/14509697/1356953

Please note that this works with java.lang.SuppressWarningsso no need to use a separate annotation.

@SuppressWarnings on a field only suppresses findbugs warnings reported for that field declaration, not every warning associated with that field.

For example, this suppresses the "Field only ever set to null" warning:

@SuppressWarnings("UWF_NULL_FIELD") String s = null; I think the best you can do is isolate the code with the warning into the smallest method you can, then suppress the warning on the whole method.

Disable future dates in jQuery UI Datepicker

Try This:

$('#datepicker').datepicker({
    endDate: new Date()
});

It will disable the future date.

Javax.net.ssl.SSLHandshakeException: javax.net.ssl.SSLProtocolException: SSL handshake aborted: Failure in SSL library, usually a protocol error

This solved it for me:

The Android documentation for SSLSocket says that TLS 1.1 and TLS 1.2 is supported within android starting API level 16+ (Android 4.1, Jelly Bean). But it is by default disabled but starting with API level 20+ (Android 4.4 for watch, Kitkat Watch and Android 5.0 for phone, Lollipop) they are enabled. But it is very hard to find any documentation about how to enable it for phones running 4.1 for example. To enable TLS 1.1 and 1.2 you need to create a custom SSLSocketFactory that is going to proxy all calls to a default SSLSocketFactory implementation. In addition to that do we have to override all createSocket methods and callsetEnabledProtocols on the returned SSLSocket to enable TLS 1.1 and TLS 1.2. For an example implementation just follow the link below.

android 4.1. enable tls1.1 and tls 1.2

Access to the path is denied

You need to find out from the application pool for the website what is the identity it is running under (by default this is Application Pool Identity) and grant that the correct permissions.

assignment operator overloading in c++

this might be helpful:

// Operator overloading in C++
//assignment operator overloading
#include<iostream>
using namespace std;

class Employee
{
private:
int idNum;
double salary;
public:
Employee ( ) {
    idNum = 0, salary = 0.0;
}

void setValues (int a, int b);
void operator= (Employee &emp );

};

void Employee::setValues ( int idN , int sal )
{

salary = sal; idNum = idN;

}

void Employee::operator = (Employee &emp)  // Assignment operator overloading function
{
salary = emp.salary;
}

int main ( )
{

Employee emp1;
emp1.setValues(10,33);
Employee emp2;
emp2 = emp1; // emp2 is calling object using assignment operator

}

Why doesn't JavaScript support multithreading?

Intel has been doing some open-source research on multithreading in Javascript, it was showcased recently on GDC 2012. Here is the link for the video. The research group used OpenCL which primarily focuses on Intel Chip sets and Windows OS. The project is code-named RiverTrail and the code is available on GitHub

Some more useful links:

Building a Computing Highway for Web Applications

Get method arguments using Spring AOP?

If you have to log all args or your method have one argument, you can simply use getArgs like described in previous answers.

If you have to log a specific arg, you can annoted it and then recover its value like this :

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.PARAMETER)
public @interface Data {
 String methodName() default "";
}

@Aspect
public class YourAspect {

 @Around("...")
 public Object around(ProceedingJoinPoint point) throws Throwable {
  Method method = MethodSignature.class.cast(point.getSignature()).getMethod();
  Object[] args = point.getArgs();
  StringBuilder data = new StringBuilder();
    Annotation[][] parameterAnnotations = method.getParameterAnnotations();
    for (int argIndex = 0; argIndex < args.length; argIndex++) {
        for (Annotation paramAnnotation : parameterAnnotations[argIndex]) {
            if (!(paramAnnotation instanceof Data)) {
                continue;
            }
            Data dataAnnotation = (Data) paramAnnotation;
            if (dataAnnotation.methodName().length() > 0) {
                Object obj = args[argIndex];
                Method dataMethod = obj.getClass().getMethod(dataAnnotation.methodName());
                data.append(dataMethod.invoke(obj));
                continue;
            }
            data.append(args[argIndex]);
        }
    }
 }
}

Examples of use :

public void doSomething(String someValue, @Data String someData, String otherValue) {
    // Apsect will log value of someData param
}

public void doSomething(String someValue, @Data(methodName = "id") SomeObject someData, String otherValue) {
    // Apsect will log returned value of someData.id() method
}

Why is char[] preferred over String for passwords?

Some people believe that you have to overwrite the memory used to store the password once you no longer need it. This reduces the time window an attacker has to read the password from your system and completely ignores the fact that the attacker already needs enough access to hijack the JVM memory to do this. An attacker with that much access can catch your key events making this completely useless (AFAIK, so please correct me if I am wrong).

Update

Thanks to the comments I have to update my answer. Apparently there are two cases where this can add a (very) minor security improvement as it reduces the time a password could land on the hard drive. Still I think it's overkill for most use cases.

  • Your target system may be badly configured or you have to assume it is and you have to be paranoid about core dumps (can be valid if the systems are not managed by an administrator).
  • Your software has to be overly paranoid to prevent data leaks with the attacker gaining access to the hardware - using things like TrueCrypt (discontinued), VeraCrypt, or CipherShed.

If possible, disabling core dumps and the swap file would take care of both problems. However, they would require administrator rights and may reduce functionality (less memory to use) and pulling RAM from a running system would still be a valid concern.

Using LIMIT within GROUP BY to get N results per group?

The following post: sql: selcting top N record per group describes the complicated way of achieving this without subqueries.

It improves on other solutions offered here by:

  • Doing everything in a single query
  • Being able to properly utilize indexes
  • Avoiding subqueries, notoriously known to produce bad execution plans in MySQL

It is however not pretty. A good solution would be achievable were Window Functions (aka Analytic Functions) enabled in MySQL -- but they are not. The trick used in said post utilizes GROUP_CONCAT, which is sometimes described as "poor man's Window Functions for MySQL".

Does a TCP socket connection have a "keep alive"?

TCP sockets remain open till they are closed.

That said, it's very difficult to detect a broken connection (broken, as in a router died, etc, as opposed to closed) without actually sending data, so most applications do some sort of ping/pong reaction every so often just to make sure the connection is still actually alive.

Regular expression to remove HTML tags from a string

You should not attempt to parse HTML with regex. HTML is not a regular language, so any regex you come up with will likely fail on some esoteric edge case. Please refer to the seminal answer to this question for specifics. While mostly formatted as a joke, it makes a very good point.


The following examples are Java, but the regex will be similar -- if not identical -- for other languages.


String target = someString.replaceAll("<[^>]*>", "");

Assuming your non-html does not contain any < or > and that your input string is correctly structured.

If you know they're a specific tag -- for example you know the text contains only <td> tags, you could do something like this:

String target = someString.replaceAll("(?i)<td[^>]*>", "");

Edit: Omega brought up a good point in a comment on another post that this would result in multiple results all being squished together if there were multiple tags.

For example, if the input string were <td>Something</td><td>Another Thing</td>, then the above would result in SomethingAnother Thing.

In a situation where multiple tags are expected, we could do something like:

String target = someString.replaceAll("(?i)<td[^>]*>", " ").replaceAll("\\s+", " ").trim();

This replaces the HTML with a single space, then collapses whitespace, and then trims any on the ends.

Meaning of "referencing" and "dereferencing" in C

find the below explanation:

int main()
{
    int a = 10;// say address of 'a' is 2000;
    int *p = &a; //it means 'p' is pointing[referencing] to 'a'. i.e p->2000
    int c = *p; //*p means dereferncing. it will give the content of the address pointed by 'p'. in this case 'p' is pointing to 2000[address of 'a' variable], content of 2000 is 10. so *p will give 10. 
}

conclusion :

  1. & [address operator] is used for referencing.
  2. * [star operator] is used for de-referencing .

How to change the font size and color of x-axis and y-axis label in a scatterplot with plot function in R?

Look at ?par for the various graphics parameters.

In general cex controls size, col controls colour. If you want to control the colour of a label, the par is col.lab, the colour of the axis annotations col.axis, the colour of the main text, col.main etc. The names are quite intuitive, once you know where to begin.

For example

x <- 1:10
y <- 1:10

plot(x , y,xlab="x axis", ylab="y axis",  pch=19, col.axis = 'blue', col.lab = 'red', cex.axis = 1.5, cex.lab = 2)

enter image description here

If you need to change the colour / style of the surrounding box and axis lines, then look at ?axis or ?box, and you will find that you will be using the same parameter names within calls to box and axis.

You have a lot of control to make things however you wish.

eg

plot(x , y,xlab="x axis", ylab="y axis",  pch=19,  cex.lab = 2, axes = F,col.lab = 'red')
box(col = 'lightblue')
axis(1, col = 'blue', col.axis = 'purple', col.ticks = 'darkred', cex.axis = 1.5, font = 2, family = 'serif')
axis(2, col = 'maroon', col.axis = 'pink', col.ticks = 'limegreen', cex.axis = 0.9, font =3, family = 'mono')

enter image description here

Which is seriously ugly, but shows part of what you can control

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

If the client has Java installed, you could do something like this:

ipAddress = java.net.InetAddress.getLocalHost().getHostAddress();

Other than that, you will probably have to use a server side script.

Convert/cast an stdClass object to another class

consider adding a new method to BusinessClass:

public static function fromStdClass(\stdClass $in): BusinessClass
{
  $out                   = new self();
  $reflection_object     = new \ReflectionObject($in);
  $reflection_properties = $reflection_object->getProperties();
  foreach ($reflection_properties as $reflection_property)
  {
    $name = $reflection_property->getName();
    if (property_exists('BusinessClass', $name))
    {
      $out->{$name} = $in->$name;
    }
  }
  return $out;
}

then you can make a new BusinessClass from $stdClass:

$converted = BusinessClass::fromStdClass($stdClass);

How do I write data to csv file in columns and rows from a list in python?

Well, if you are writing to a CSV file, then why do you use space as a delimiter? CSV files use commas or semicolons (in Excel) as cell delimiters, so if you use delimiter=' ', you are not really producing a CSV file. You should simply construct csv.writer with the default delimiter and dialect. If you want to read the CSV file later into Excel, you could specify the Excel dialect explicitly just to make your intention clear (although this dialect is the default anyway):

example = csv.writer(open("test.csv", "wb"), dialect="excel")

Javascript find json value

I suggest using JavaScript's Array method filter() to identify an element by value. It filters data by using a "function to test each element of the array. Return true to keep the element, false otherwise.."

The following function filters the data, returning data for which the callback returns true, i.e. where data.code equals the requested country code.

function getCountryByCode(code) {
  return data.filter(
      function(data){ return data.code == code }
  );
}

var found = getCountryByCode('DZ');

See the demonstration below:

_x000D_
_x000D_
var data = [{_x000D_
  "name": "Afghanistan",_x000D_
  "code": "AF"_x000D_
}, {_x000D_
  "name": "Åland Islands",_x000D_
  "code": "AX"_x000D_
}, {_x000D_
  "name": "Albania",_x000D_
  "code": "AL"_x000D_
}, {_x000D_
  "name": "Algeria",_x000D_
  "code": "DZ"_x000D_
}];_x000D_
_x000D_
_x000D_
function getCountryByCode(code) {_x000D_
  return data.filter(_x000D_
    function(data) {_x000D_
      return data.code == code_x000D_
    }_x000D_
  );_x000D_
}_x000D_
_x000D_
var found = getCountryByCode('DZ');_x000D_
_x000D_
document.getElementById('output').innerHTML = found[0].name;
_x000D_
<div id="output"></div>
_x000D_
_x000D_
_x000D_

Here's a JSFiddle.

Android : change button text and background color

When you create an App, a file called styles.xml will be created in your res/values folder. If you change the styles, you can change the background, text color, etc for all your layouts. That way you don’t have to go into each individual layout and change the it manually.

styles.xml:

<resources xmlns:android="http://schemas.android.com/apk/res/android">
<style name="Theme.AppBaseTheme" parent="@android:style/Theme.Light">
    <item name="android:editTextColor">#295055</item> 
    <item name="android:textColorPrimary">#295055</item>
    <item name="android:textColorSecondary">#295055</item>
    <item name="android:textColorTertiary">#295055</item>
    <item name="android:textColorPrimaryInverse">#295055</item>
    <item name="android:textColorSecondaryInverse">#295055</item>
    <item name="android:textColorTertiaryInverse">#295055</item>

     <item name="android:windowBackground">@drawable/custom_background</item>        
</style>

<!-- Application theme. -->
<style name="AppTheme" parent="AppBaseTheme">
    <!-- All customizations that are NOT specific to a particular API-level can go here. -->
</style>

parent="@android:style/Theme.Light" is Google’s native colors. Here is a reference of what the native styles are: https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/res/res/values/themes.xml

name="Theme.AppBaseTheme" means that you are creating a style that inherits all the styles from parent="@android:style/Theme.Light". This part you can ignore unless you want to inherit from AppBaseTheme again. = <style name="AppTheme" parent="AppBaseTheme">

@drawable/custom_background is a custom image I put in the drawable’s folder. It is a 300x300 png image.

#295055 is a dark blue color.

My code changes the background and text color. For Button text, please look through Google’s native stlyes (the link I gave u above).

Then in Android Manifest, remember to include the code:

<application
android:theme="@style/Theme.AppBaseTheme">

How can I use break or continue within for loop in Twig template?

A way to be able to use {% break %} or {% continue %} is to write TokenParsers for them.

I did it for the {% break %} token in the code below. You can, without much modifications, do the same thing for the {% continue %}.

  • AppBundle\Twig\AppExtension.php:

    namespace AppBundle\Twig;
    
    class AppExtension extends \Twig_Extension
    {
        function getTokenParsers() {
            return array(
                new BreakToken(),
            );
        }
    
        public function getName()
        {
            return 'app_extension';
        }
    }
    
  • AppBundle\Twig\BreakToken.php:

    namespace AppBundle\Twig;
    
    class BreakToken extends \Twig_TokenParser
    {
        public function parse(\Twig_Token $token)
        {
            $stream = $this->parser->getStream();
            $stream->expect(\Twig_Token::BLOCK_END_TYPE);
    
            // Trick to check if we are currently in a loop.
            $currentForLoop = 0;
    
            for ($i = 1; true; $i++) {
                try {
                    // if we look before the beginning of the stream
                    // the stream will throw a \Twig_Error_Syntax
                    $token = $stream->look(-$i);
                } catch (\Twig_Error_Syntax $e) {
                    break;
                }
    
                if ($token->test(\Twig_Token::NAME_TYPE, 'for')) {
                    $currentForLoop++;
                } else if ($token->test(\Twig_Token::NAME_TYPE, 'endfor')) {
                    $currentForLoop--;
                }
            }
    
    
            if ($currentForLoop < 1) {
                throw new \Twig_Error_Syntax(
                    'Break tag is only allowed in \'for\' loops.',
                    $stream->getCurrent()->getLine(),
                    $stream->getSourceContext()->getName()
                );
            }
    
            return new BreakNode();
        }
    
        public function getTag()
        {
            return 'break';
        }
    }
    
  • AppBundle\Twig\BreakNode.php:

    namespace AppBundle\Twig;
    
    class BreakNode extends \Twig_Node
    {
        public function compile(\Twig_Compiler $compiler)
        {
            $compiler
                ->write("break;\n")
            ;
        }
    }
    

Then you can simply use {% break %} to get out of loops like this:

{% for post in posts %}
    {% if post.id == 10 %}
        {% break %}
    {% endif %}
    <h2>{{ post.heading }}</h2>
{% endfor %}

To go even further, you may write token parsers for {% continue X %} and {% break X %} (where X is an integer >= 1) to get out/continue multiple loops like in PHP.

Parallel.ForEach vs Task.Factory.StartNew

In my view the most realistic scenario is when tasks have a heavy operation to complete. Shivprasad's approach focuses more on object creation/memory allocation than on computing itself. I made a research calling the following method:

public static double SumRootN(int root)
{
    double result = 0;
    for (int i = 1; i < 10000000; i++)
        {
            result += Math.Exp(Math.Log(i) / root);
        }
        return result; 
}

Execution of this method takes about 0.5sec.

I called it 200 times using Parallel:

Parallel.For(0, 200, (int i) =>
{
    SumRootN(10);
});

Then I called it 200 times using the old-fashioned way:

List<Task> tasks = new List<Task>() ;
for (int i = 0; i < loopCounter; i++)
{
    Task t = new Task(() => SumRootN(10));
    t.Start();
    tasks.Add(t);
}

Task.WaitAll(tasks.ToArray()); 

First case completed in 26656ms, the second in 24478ms. I repeated it many times. Everytime the second approach is marginaly faster.

How exactly to use Notification.Builder

I was having a problem building notifications (only developing for Android 4.0+). This link showed me exactly what I was doing wrong and says the following:

Required notification contents

A Notification object must contain the following:

A small icon, set by setSmallIcon()
A title, set by setContentTitle()
Detail text, set by setContentText()

Basically I was missing one of these. Just as a basis for troubleshooting with this, make sure you have all of these at the very least. Hopefully this will save someone else a headache.

How to remove items from a list while iterating?

uppose a list of number and you want to remove all no which are divisible by 3,

list_number =[i for i in range(100)]

using list comprehension,this will careate a new list and create new memory space

new_list =[i for i in list_number if i%3!=0]

using lambda filter function, this will create resultant new list and consume memeory space

new_list = list(filter(lambda x:x%3!=0, list_number))

without consuming memory space for new list and modify existing list

for index, value in enumerate(list_number):
    if list_number[index]%3==0:
        list_number.remove(value)

Can I remove the URL from my print css, so the web address doesn't print?

Historically, it's been impossible to make these things disappear as they are user settings and not considered part of the page you have control over.

http://css-discuss.incutio.com/wiki/Print_Stylesheets#Print_headers.2Ffooters_and_print_margins

However, as of 2017, the @page at-rule has been standardized, which can be used to hide the page title and date in modern browsers:

@page { size: auto; margin: 0mm; }

Credit to Vigneswaran S for this tip.

How to Select Top 100 rows in Oracle?

you should use rownum in oracle to do what you seek

where rownum <= 100

see also those answers to help you

limit in oracle

select top in oracle

select top in oracle 2

How do you remove all the options of a select box and then add one option and select it with jQuery?

$('#mySelect')
    .find('option')
    .remove()
    .end()
    .append('<option value="whatever">text</option>')
    .val('whatever')
;

Alter column in SQL Server

I think you want this syntax:

ALTER TABLE tb_TableName  
add constraint cnt_Record_Status Default '' for Record_Status

Based on some of your comments, I am going to guess that you might already have null values in your table which is causing the alter of the column to not null to fail. If that is the case, then you should run an UPDATE first. Your script will be:

update tb_TableName
set Record_Status  = ''
where Record_Status is null

ALTER TABLE tb_TableName
ALTER COLUMN Record_Status VARCHAR(20) NOT NULL

ALTER TABLE tb_TableName
ADD CONSTRAINT DEF_Name DEFAULT '' FOR Record_Status

See SQL Fiddle with demo

How to split a dataframe string column into two columns?

I saw that no one had used the slice method, so here I put my 2 cents here.

df["<col_name>"].str.slice(stop=5)
df["<col_name>"].str.slice(start=6)

This method will create two new columns.

Form submit with AJAX passing form data to PHP without page refresh

JS Code

    $("#submit").click(function() { 
    //get input field values
    var name            = $('#name').val(); 
    var email           = $('#email').val();
    var message         = $('#comment').val();
    var flag = true;
    /********validate all our form fields***********/
    /* Name field validation  */
    if(name==""){ 
        $('#name').css('border-color','red'); 
        flag = false;
    }
    /* email field validation  */
    if(email==""){ 
        $('#email').css('border-color','red'); 
        flag = false;
    } 
    /* message field validation */
    if(message=="") {  
       $('#comment').css('border-color','red'); 
        flag = false;
    }
    /********Validation end here ****/
    /* If all are ok then we send ajax request to email_send.php *******/
    if(flag) 
    {
        $.ajax({
            type: 'post',
            url: "email_send.php", 
            dataType: 'json',
            data: 'username='+name+'&useremail='+email+'&message='+message,
            beforeSend: function() {
                $('#submit').attr('disabled', true);
                $('#submit').after('<span class="wait">&nbsp;<img src="image/loading.gif" alt="" /></span>');
            },
            complete: function() {
                $('#submit').attr('disabled', false);
                $('.wait').remove();
            },  
            success: function(data)
            {
                if(data.type == 'error')
                {
                    output = '<div class="error">'+data.text+'</div>';
                }else{
                    output = '<div class="success">'+data.text+'</div>';
                    $('input[type=text]').val(''); 
                    $('#contactform textarea').val(''); 
                }

                $("#result").hide().html(output).slideDown();           
                }
        });
    }
});
//reset previously set border colors and hide all message on .keyup()
$("#contactform input, #contactform textarea").keyup(function() { 
    $("#contactform input, #contactform textarea").css('border-color',''); 
    $("#result").slideUp();
});

HTML Form

<div  class="cover">
<div id="result"></div>
<div id="contactform">
    <p class="contact"><label for="name">Name</label></p>
    <input id="name" name="name" placeholder="Yourname" type="text">

    <p class="contact"><label for="email">Email</label></p>
    <input id="email" name="email" placeholder="[email protected]" type="text">

    <p class="contact"><label for="comment">Your Message</label></p>
    <textarea name="comment" id="comment" tabindex="4"></textarea> <br>
    <input name="submit" id="submit" tabindex="5" value="Send Mail" type="submit" style="width:200px;">
</div>

PHP Code

if ($_SERVER['REQUEST_METHOD'] == 'POST') {

//check if its an ajax request, exit if not
if (!isset($_SERVER['HTTP_X_REQUESTED_WITH']) AND strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) != 'xmlhttprequest') {

    //exit script outputting json data
    $output = json_encode(
            array(
                'type' => 'error',
                'text' => 'Request must come from Ajax'
    ));

    die($output);
}

//check $_POST vars are set, exit if any missing
if (!isset($_POST["username"]) || !isset($_POST["useremail"]) || !isset($_POST["message"])) {
    $output = json_encode(array('type' => 'error', 'text' => 'Input fields are empty!'));
    die($output);
}

//Sanitize input data using PHP filter_var().
$username = filter_var(trim($_POST["username"]), FILTER_SANITIZE_STRING);
$useremail = filter_var(trim($_POST["useremail"]), FILTER_SANITIZE_EMAIL);
$message = filter_var(trim($_POST["message"]), FILTER_SANITIZE_STRING);

//additional php validation
if (strlen($username) < 4) { // If length is less than 4 it will throw an HTTP error.
    $output = json_encode(array('type' => 'error', 'text' => 'Name is too short!'));
    die($output);
}
if (!filter_var($useremail, FILTER_VALIDATE_EMAIL)) { //email validation
    $output = json_encode(array('type' => 'error', 'text' => 'Please enter a valid email!'));
    die($output);
}
if (strlen($message) < 5) { //check emtpy message
    $output = json_encode(array('type' => 'error', 'text' => 'Too short message!'));
    die($output);
}

$to = "[email protected]"; //Replace with recipient email address
//proceed with PHP email.
$headers = 'From: ' . $useremail . '' . "\r\n" .
        'Reply-To: ' . $useremail . '' . "\r\n" .
        'X-Mailer: PHP/' . phpversion();

$sentMail = @mail($to, $subject, $message . '  -' . $username, $headers);
//$sentMail = true;
if (!$sentMail) {
    $output = json_encode(array('type' => 'error', 'text' => 'Could not send mail! Please contact administrator.'));
    die($output);
} else {
    $output = json_encode(array('type' => 'message', 'text' => 'Hi ' . $username . ' Thank you for your email'));
    die($output);
}

This page has a simpler example http://wearecoders.net/submit-form-without-page-refresh-with-php-and-ajax/

How to generate a number of most distinctive colors in R?

I would recomend to use an external source for large color palettes.

http://tools.medialab.sciences-po.fr/iwanthue/

has a service to compose any size of palette according to various parameters and

https://graphicdesign.stackexchange.com/questions/3682/where-can-i-find-a-large-palette-set-of-contrasting-colors-for-coloring-many-d/3815

discusses the generic problem from a graphics designers perspective and gives lots of examples of usable palettes.

To comprise a palette from RGB values you just have to copy the values in a vector as in e.g.:

colors37 = c("#466791","#60bf37","#953ada","#4fbe6c","#ce49d3","#a7b43d","#5a51dc","#d49f36","#552095","#507f2d","#db37aa","#84b67c","#a06fda","#df462a","#5b83db","#c76c2d","#4f49a3","#82702d","#dd6bbb","#334c22","#d83979","#55baad","#dc4555","#62aad3","#8c3025","#417d61","#862977","#bba672","#403367","#da8a6d","#a79cd4","#71482c","#c689d0","#6b2940","#d593a7","#895c8b","#bd5975")

$_SERVER["REMOTE_ADDR"] gives server IP rather than visitor IP

When using $_SERVER["REMOTE_ADDR"], I get the server's IP address rather than the visitor's.

Then something is wrong, or odd, with your configuration.

  • Are you using some sort of reverse proxy? In that case, @simshaun's suggestion may work.

  • Do you have anything else out of the ordinary in your web server config?

  • Can you show the PHP code you are using?

  • Can you show what the address looks like. Is it a local one, or a Internet address?

java : non-static variable cannot be referenced from a static context Error

Java has two kind of Variables

a)
Class Level (Static) :
They are one per Class.Say you have Student Class and defined name as static variable.Now no matter how many student object you create all will have same name.

Object Level :
They belong to per Object.If name is non-static ,then all student can have different name.

b)
Class Level :
This variables are initialized on Class load.So even if no student object is created you can still access and use static name variable.

Object Level: They will get initialized when you create a new object ,say by new();

C)
Your Problem : Your class is Just loaded in JVM and you have called its main (static) method : Legally allowed.

Now from that you want to call an Object varibale : Where is the object ??

You have to create a Object and then only you can access Object level varibales.

Cannot use a leading ../ to exit above the top directory

You have an image or a favicon link of the style ="../" somewhere, that if the "../" were valid, would go beyond the top of the site, like this:

Image:

http://example.com/Images/test.jpg

Page

http://example.com/Pages/test.aspx

Valid on that page: ../Images/test.jpg
Would throw an error: ../../Images/test.jpg

lambda expression join multiple tables with select and where clause

If I understand your questions correctly, all you need to do is add the .Where(m => m.r.u.UserId == 1):

    var UserInRole = db.UserProfiles.
        Join(db.UsersInRoles, u => u.UserId, uir => uir.UserId,
        (u, uir) => new { u, uir }).
        Join(db.Roles, r => r.uir.RoleId, ro => ro.RoleId, (r, ro) => new { r, ro })
        .Where(m => m.r.u.UserId == 1)
        .Select (m => new AddUserToRole
        {
            UserName = m.r.u.UserName,
            RoleName = m.ro.RoleName
        });

Hope that helps.

How do I convert seconds to hours, minutes and seconds?

The solutions above will work if you're looking to convert a single value for "seconds since midnight" on a date to a datetime object or a string with HH:MM:SS, but I landed on this page because I wanted to do this on a whole dataframe column in pandas. If anyone else is wondering how to do this for more than a single value at a time, what ended up working for me was:

 mydate='2015-03-01'
 df['datetime'] = datetime.datetime(mydate) + \ 
                  pandas.to_timedelta(df['seconds_since_midnight'], 's')

The difference between Classes, Objects, and Instances

Java (and any other programming language) is modeled in terms of types and values. At the theoretical level, a value is a representation for some quantum of information, and a type is a set of values. When we say value X is an instance of type Y, we are simply saying that X is a member of the set of values that is the type Y.

So that's what the term "instance" really means: it describes a relationship not a thing.

The type system of the Java programming language supports two kinds of types, primitive types and reference types. The reference types are further divided into the classes and array types. A Java object is an instance of a reference type.

An object is a class instance or an array. (JLS 4.3.1)

That's the type theoretic view.

In practice, most Java developers treat the words "instance" and "object" as synonyms. (And that includes me then I'm trying to explain something quickly.) And most developers use the word "value" rather than "instance" to refer to an instance of a primitive type.

How to use a variable for a key in a JavaScript object literal?

Adding square bracket around the variable works good for me. Try this

var thetop = 'top';
<something>.stop().animate(
    { [thetop] : 10 }, 10
);

What's is the difference between train, validation and test set, in neural networks?

Training set: A set of examples used for learning, that is to fit the parameters [i.e., weights] of the classifier.

Validation set: A set of examples used to tune the parameters [i.e., architecture, not weights] of a classifier, for example to choose the number of hidden units in a neural network.

Test set: A set of examples used only to assess the performance [generalization] of a fully specified classifier.

From ftp://ftp.sas.com/pub/neural/FAQ1.txt section "What are the population, sample, training set, design set, validation"

The error surface will be different for different sets of data from your data set (batch learning). Therefore if you find a very good local minima for your test set data, that may not be a very good point, and may be a very bad point in the surface generated by some other set of data for the same problem. Therefore you need to compute such a model which not only finds a good weight configuration for the training set but also should be able to predict new data (which is not in the training set) with good error. In other words the network should be able to generalize the examples so that it learns the data and does not simply remembers or loads the training set by overfitting the training data.

The validation data set is a set of data for the function you want to learn, which you are not directly using to train the network. You are training the network with a set of data which you call the training data set. If you are using gradient based algorithm to train the network then the error surface and the gradient at some point will completely depend on the training data set thus the training data set is being directly used to adjust the weights. To make sure you don't overfit the network you need to input the validation dataset to the network and check if the error is within some range. Because the validation set is not being using directly to adjust the weights of the netowork, therefore a good error for the validation and also the test set indicates that the network predicts well for the train set examples, also it is expected to perform well when new example are presented to the network which was not used in the training process.

Early stopping is a way to stop training. There are different variations available, the main outline is, both the train and the validation set errors are monitored, the train error decreases at each iteration (backprop and brothers) and at first the validation error decreases. The training is stopped at the moment the validation error starts to rise. The weight configuration at this point indicates a model, which predicts the training data well, as well as the data which is not seen by the network . But because the validation data actually affects the weight configuration indirectly to select the weight configuration. This is where the Test set comes in. This set of data is never used in the training process. Once a model is selected based on the validation set, the test set data is applied on the network model and the error for this set is found. This error is a representative of the error which we can expect from absolutely new data for the same problem.

EDIT:

Also, in the case you do not have enough data for a validation set, you can use crossvalidation to tune the parameters as well as estimate the test error.

Regular Expression to match only alphabetic characters

[a-zA-Z] should do that just fine.

You can reference the cheat sheet.

How to disable text selection highlighting

Check my solution without JavaScript:

jsFiddle

_x000D_
_x000D_
li:hover {_x000D_
    background-color: silver;_x000D_
}_x000D_
#id1:before {_x000D_
    content: "File";_x000D_
}_x000D_
#id2:before {_x000D_
    content: "Edit";_x000D_
}_x000D_
#id3:before {_x000D_
    content: "View";_x000D_
}
_x000D_
<ul>_x000D_
    <li><a id="id1" href="www.w1.com"></a>_x000D_
    <li><a id="id2" href="www.w2.com"></a>_x000D_
    <li><a id="id3" href="www.w3.com"></a>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Popup menu with my technique applied: http://jsfiddle.net/y4Lac/2/

How to import a module in Python with importlib.import_module

And don't forget to create a __init__.py with each folder/subfolder (even if they are empty)

android ellipsize multiline textview

Extend TextView and override these methods:

CharSequence origText = "";
int maxLines = 2;

@Override
public void setText(CharSequence text, BufferType type) {
    super.setText(text, type);
    origText = text;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    CharSequence text = origText;
    onPreDraw();

    while(getLineCount() > maxLines) {
        text = text.subSequence(0, text.length()-1);
        super.setText(text + "...");
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        onPreDraw();
    }

}

How can I get the corresponding table header (th) from a table cell (td)?

var $th = $td.closest('tbody').prev('thead').find('> tr > th:eq(' + $td.index() + ')');

Or a little bit simplified

var $th = $td.closest('table').find('th').eq($td.index());

How to get a tab character?

As mentioned, for efficiency reasons sequential spaces are consolidated into one space the browser actually displays. Remember what the ML in HTML stand for. It's a Mark-up Language, designed to control how text is displayed.. not whitespace :p

Still, you can pretend the browser respects tabs since all the TAB does is prepend 4 spaces, and that's easy with CSS. either in line like ...

 <div style="padding-left:4.00em;">Indenented text </div>

Or as a regular class in a style sheet

.tabbed {padding-left:4.00em;}

Then the HTML might look like

<p>regular paragraph regular paragraph regular paragraph</p>
<p class="tabbed">Indented text Indented text Indented text</p>
<p>regular paragraph regular paragraph regular paragraph</p>

Hex-encoded String to Byte Array

Java SE 6 or Java EE 5 provides a method to do this now so there is no need for extra libraries.

The method is DatatypeConverter.parseHexBinary

In this case it can be used as follows:

String str = "9B7D2C34A366BF890C730641E6CECF6F";
byte[] bytes = DatatypeConverter.parseHexBinary(str);

The class also provides type conversions for many other formats that are generally used in XML.

Initializing entire 2D array with one value

You get this behavior, because int array [ROW][COLUMN] = {1}; does not mean "set all items to one". Let me try to explain how this works step by step.

The explicit, overly clear way of initializing your array would be like this:

#define ROW 2
#define COLUMN 2

int array [ROW][COLUMN] =
{
  {0, 0},
  {0, 0}
};

However, C allows you to leave out some of the items in an array (or struct/union). You could for example write:

int array [ROW][COLUMN] =
{
  {1, 2}
};

This means, initialize the first elements to 1 and 2, and the rest of the elements "as if they had static storage duration". There is a rule in C saying that all objects of static storage duration, that are not explicitly initialized by the programmer, must be set to zero.

So in the above example, the first row gets set to 1,2 and the next to 0,0 since we didn't give them any explicit values.

Next, there is a rule in C allowing lax brace style. The first example could as well be written as

int array [ROW][COLUMN] = {0, 0, 0, 0};

although of course this is poor style, it is harder to read and understand. But this rule is convenient, because it allows us to write

int array [ROW][COLUMN] = {0};

which means: "initialize the very first column in the first row to 0, and all other items as if they had static storage duration, ie set them to zero."

therefore, if you attempt

int array [ROW][COLUMN] = {1};

it means "initialize the very first column in the first row to 1 and set all other items to zero".

CSS center display inline block?

This will horizontally center an inline-block element without needing to modify its parent's styles:

  display: inline-block;
  position: relative;
  // Move the element to the left by 50% of the container's width
  left: 50%; 
  // Calculates 50% of the element's width, and moves it by that
  // amount across the X-axis to the left
  transform: translateX(-50%);

Entity Framework - Linq query with order by and group by

You can try to cast the result of GroupBy and Take into an Enumerable first then process the rest (building on the solution provided by NinjaNye

var groupByReference = (from m in context.Measurements
                              .GroupBy(m => m.Reference)
                              .Take(numOfEntries).AsEnumerable()
                               .Select(g => new {Creation = g.FirstOrDefault().CreationTime, 
                                             Avg = g.Average(m => m.CreationTime.Ticks),
                                                Items = g })
                              .OrderBy(x => x.Creation)
                              .ThenBy(x => x.Avg)
                              .ToList() select m);

Your sql query would look similar (depending on your input) this

SELECT TOP (3) [t1].[Reference] AS [Key]
FROM (
    SELECT [t0].[Reference]
    FROM [Measurements] AS [t0]
    GROUP BY [t0].[Reference]
    ) AS [t1]
GO

-- Region Parameters
DECLARE @x1 NVarChar(1000) = 'Ref1'
-- EndRegion
SELECT [t0].[CreationTime], [t0].[Id], [t0].[Reference]
FROM [Measurements] AS [t0]
WHERE @x1 = [t0].[Reference]
GO

-- Region Parameters
DECLARE @x1 NVarChar(1000) = 'Ref2'
-- EndRegion
SELECT [t0].[CreationTime], [t0].[Id], [t0].[Reference]
FROM [Measurements] AS [t0]
WHERE @x1 = [t0].[Reference]

how to call an ASP.NET c# method using javascript

The Jayrock RPC library is a great tool for doing this in a nice familliar way for C# developers. It allows you to create a .NET class with the methods you require, and add this class as a script (in a roundabout way) to your page. You can then create a js object of your type and call methods as you would any other object.

It essentially hides away ajax implementation and presents RPC in a familliar format. Mind you the best option really is to use ASP.NET MVC and use jQuery ajax calls to action methods - much more concise and less messing about!

How to change colour of blue highlight on select box dropdown

When we click on an "input" element, it gets "focused" on. Removing the blue highlighter for this "focus" action is as simple as below. To give it gray color, you could define a gray border.

select:focus{
    border-color: gray;
    outline:none;
}

Python Flask, how to set content type

Usually you don’t have to create the Response object yourself because make_response() will take care of that for you.

from flask import Flask, make_response                                      
app = Flask(__name__)                                                       

@app.route('/')                                                             
def index():                                                                
    bar = '<body>foo</body>'                                                
    response = make_response(bar)                                           
    response.headers['Content-Type'] = 'text/xml; charset=utf-8'            
    return response

One more thing, it seems that no one mentioned the after_this_request, I want to say something:

after_this_request

Executes a function after this request. This is useful to modify response objects. The function is passed the response object and has to return the same or a new one.

so we can do it with after_this_request, the code should look like this:

from flask import Flask, after_this_request
app = Flask(__name__)

@app.route('/')
def index():
    @after_this_request
    def add_header(response):
        response.headers['Content-Type'] = 'text/xml; charset=utf-8'
        return response
    return '<body>foobar</body>'

Synchronously waiting for an async operation, and why does Wait() freeze the program here

With small custom synchronization context, sync function can wait for completion of async function, without creating deadlock. Here is small example for WinForms app.

Imports System.Threading
Imports System.Runtime.CompilerServices

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        SyncMethod()
    End Sub

    ' waiting inside Sync method for finishing async method
    Public Sub SyncMethod()
        Dim sc As New SC
        sc.WaitForTask(AsyncMethod())
        sc.Release()
    End Sub

    Public Async Function AsyncMethod() As Task(Of Boolean)
        Await Task.Delay(1000)
        Return True
    End Function

End Class

Public Class SC
    Inherits SynchronizationContext

    Dim OldContext As SynchronizationContext
    Dim ContextThread As Thread

    Sub New()
        OldContext = SynchronizationContext.Current
        ContextThread = Thread.CurrentThread
        SynchronizationContext.SetSynchronizationContext(Me)
    End Sub

    Dim DataAcquired As New Object
    Dim WorkWaitingCount As Long = 0
    Dim ExtProc As SendOrPostCallback
    Dim ExtProcArg As Object

    <MethodImpl(MethodImplOptions.Synchronized)>
    Public Overrides Sub Post(d As SendOrPostCallback, state As Object)
        Interlocked.Increment(WorkWaitingCount)
        Monitor.Enter(DataAcquired)
        ExtProc = d
        ExtProcArg = state
        AwakeThread()
        Monitor.Wait(DataAcquired)
        Monitor.Exit(DataAcquired)
    End Sub

    Dim ThreadSleep As Long = 0

    Private Sub AwakeThread()
        If Interlocked.Read(ThreadSleep) > 0 Then ContextThread.Resume()
    End Sub

    Public Sub WaitForTask(Tsk As Task)
        Dim aw = Tsk.GetAwaiter

        If aw.IsCompleted Then Exit Sub

        While Interlocked.Read(WorkWaitingCount) > 0 Or aw.IsCompleted = False
            If Interlocked.Read(WorkWaitingCount) = 0 Then
                Interlocked.Increment(ThreadSleep)
                ContextThread.Suspend()
                Interlocked.Decrement(ThreadSleep)
            Else
                Interlocked.Decrement(WorkWaitingCount)
                Monitor.Enter(DataAcquired)
                Dim Proc = ExtProc
                Dim ProcArg = ExtProcArg
                Monitor.Pulse(DataAcquired)
                Monitor.Exit(DataAcquired)
                Proc(ProcArg)
            End If
        End While

    End Sub

     Public Sub Release()
         SynchronizationContext.SetSynchronizationContext(OldContext)
     End Sub

End Class

How can I revert a single file to a previous version?

Git doesn't think in terms of file versions. A version in git is a snapshot of the entire tree.

Given this, what you really want is a tree that has the latest content of most files, but with the contents of one file the same as it was 5 commits ago. This will take the form of a new commit on top of the old ones, and the latest version of the tree will have what you want.

I don't know if there's a one-liner that will revert a single file to the contents of 5 commits ago, but the lo-fi solution should work: checkout master~5, copy the file somewhere else, checkout master, copy the file back, then commit.

Post to another page within a PHP script

index.php

$url = 'http://[host]/test.php';
$json = json_encode(['name' => 'Jhonn', 'phone' => '128000000000']);

$options = ['http' => [
    'method' => 'POST',
    'header' => 'Content-type:application/json',
    'content' => $json
]];

$context = stream_context_create($options);
$response = file_get_contents($url, false, $context);

test.php

$raw = file_get_contents('php://input');
$data = json_decode($raw, true);
echo $data['name']; // Jhonn

Spring 3.0: Unable to locate Spring NamespaceHandler for XML schema namespace

In case someone else runs into this problem, I just did using Eclipse; running the project via the right click action. This error occurred in the J2EE view, but did NOT occur in the Java view. Not sure - assuming something with adding libraries to the correct 'lib' directory.

I am also using a Maven project, allowing m2eclipse to manage dependancies.

What is the difference between Swing and AWT?

AWT 1 . AWT occupies more memory space 2 . AWT is platform dependent 3 . AWT require javax.awt package

swings 1 . Swing occupies less memory space 2 . Swing component is platform independent 3 . Swing requires javax.swing package

Can I change the scroll speed using css or jQuery?

No. Scroll speed is determined by the browser (and usually directly by the settings on the computer/device). CSS and Javascript don't (or shouldn't) have any way to affect system settings.

That being said, there are likely a number of ways you could try to fake a different scroll speed by moving your own content around in such a way as to counteract scrolling. However, I think doing so is a HORRIBLE idea in terms of usability, accessibility, and respect for your users, but I would start by finding events that your target browsers fire that indicate scrolling.

Once you can capture the scroll event (assuming you can), then you would be able to adjust your content dynamically so that the portion you want is visible.

Another approach would be to deal with this in Flash, which does give you at least some level of control over scrolling events.

How to call on a function found on another file?

Small addition to @user995502's answer on how to run the program.

g++ player.cpp main.cpp -o main.out && ./main.out

Good examples of python-memcache (memcached) being used in Python?

It's fairly simple. You write values using keys and expiry times. You get values using keys. You can expire keys from the system.

Most clients follow the same rules. You can read the generic instructions and best practices on the memcached homepage.

If you really want to dig into it, I'd look at the source. Here's the header comment:

"""
client module for memcached (memory cache daemon)

Overview
========

See U{the MemCached homepage<http://www.danga.com/memcached>} for more about memcached.

Usage summary
=============

This should give you a feel for how this module operates::

    import memcache
    mc = memcache.Client(['127.0.0.1:11211'], debug=0)

    mc.set("some_key", "Some value")
    value = mc.get("some_key")

    mc.set("another_key", 3)
    mc.delete("another_key")

    mc.set("key", "1")   # note that the key used for incr/decr must be a string.
    mc.incr("key")
    mc.decr("key")

The standard way to use memcache with a database is like this::

    key = derive_key(obj)
    obj = mc.get(key)
    if not obj:
        obj = backend_api.get(...)
        mc.set(key, obj)

    # we now have obj, and future passes through this code
    # will use the object from the cache.

Detailed Documentation
======================

More detailed documentation is available in the L{Client} class.
"""

Using pg_dump to only get insert statements from one table within database

If you want to DUMP your inserts into an .sql file:

  1. cd to the location which you want to .sql file to be located
  2. pg_dump --column-inserts --data-only --table=<table> <database> > my_dump.sql

Note the > my_dump.sql command. This will put everything into a sql file named my_dump

How do I update Node.js?

Get current time in seconds since the Epoch on Linux, Bash

With most Awk implementations:

awk 'BEGIN {srand(); print srand()}'

Shuffle DataFrame rows

Here is another way:

df['rnd'] = np.random.rand(len(df)) df = df.sort_values(by='rnd', inplace=True).drop('rnd', axis=1)

How to get the current user in ASP.NET MVC

For what it's worth, in ASP.NET MVC 3 you can just use User which returns the user for the current request.

How can I replace a regex substring match in Javascript?

I think the simplest way to achieve your goal is this:

var str   = 'asd-0.testing';
var regex = /(asd-)(\d)(\.\w+)/;
var anyNumber = 1;
var res = str.replace(regex, `$1${anyNumber}$3`);

Using ping in c#

Imports System.Net.NetworkInformation


Public Function PingHost(ByVal nameOrAddress As String) As Boolean
    Dim pingable As Boolean = False
    Dim pinger As Ping
    Dim lPingReply As PingReply

    Try
        pinger = New Ping()
        lPingReply = pinger.Send(nameOrAddress)
        MessageBox.Show(lPingReply.Status)
        If lPingReply.Status = IPStatus.Success Then

            pingable = True
        Else
            pingable = False
        End If


    Catch PingException As Exception
        pingable = False
    End Try
    Return pingable
End Function

Is it possible to format an HTML tooltip (title attribute)?

No. But there are other options out there like Overlib, and jQuery that allow you this freedom.

Personally, I would suggest jQuery as the route to take. It's typically very unobtrusive, and requires no additional setup in the markup of your site (with the exception of adding the jquery script tag in your <head>).

Typescript: How to define type for a function callback (as any function type, not universal any) used in a method parameter

Following from Ryan's answer, I think that the interface you are looking for is defined as follows:

interface Param {
    title: string;
    callback: () => void;
}

How do I calculate the percentage of a number?

Divide $percentage by 100 and multiply to $totalWidth. Simple maths.

In git, what is the difference between merge --squash and rebase?

Let's start by the following example:

enter image description here

Now we have 3 options to merge changes of feature branch into master branch:

  1. Merge commits
    Will keep all commits history of the feature branch and move them into the master branch
    Will add extra dummy commit.

  2. Rebase and merge
    Will append all commits history of the feature branch in the front of the master branch
    Will NOT add extra dummy commit.

  3. Squash and merge
    Will group all feature branch commits into one commit then append it in the front of the master branch
    Will add extra dummy commit.

You can find below how the master branch will look after each one of them.

enter image description here

In all cases:
We can safely DELETE the feature branch.

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

I figured out myself.

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

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

Oracle REPLACE() function isn't handling carriage-returns & line-feeds

Another way is to use TRANSLATE:

TRANSLATE (col_name, 'x'||CHR(10)||CHR(13), 'x')

The 'x' is any character that you don't want translated to null, because TRANSLATE doesn't work right if the 3rd parameter is null.

Best way to test if a row exists in a MySQL table

Or you can insert raw sql part to conditions so I have 'conditions'=>array('Member.id NOT IN (SELECT Membership.member_id FROM memberships AS Membership)')

DataTable, How to conditionally delete rows

Extension method based on Linq

public static void DeleteRows(this DataTable dt, Func<DataRow, bool> predicate)
{
    foreach (var row in dt.Rows.Cast<DataRow>().Where(predicate).ToList())
        row.Delete();
}

Then use:

DataTable dt = GetSomeData();
dt.DeleteRows(r => r.Field<double>("Amount") > 123.12 && r.Field<string>("ABC") == "XYZ");

CSS transition fade on hover

I recommend you to use an unordered list for your image gallery.

You should use my code unless you want the image to gain instantly 50% opacity after you hover out. You will have a smoother transition.

#photos li {
    opacity: .5;
    transition: opacity .5s ease-out;
    -moz-transition: opacity .5s ease-out;
    -webkit-transition: opacity .5s ease-out;
    -o-transition: opacity .5s ease-out;
}

#photos li:hover {
    opacity: 1;
}

Using Exit button to close a winform program

You can also do like this:

private void button2_Click(object sender, EventArgs e)
{
    System.Windows.Forms.Application.ExitThread();
}

Unix's 'ls' sort by name

NOTICE: "a" comes AFTER "Z":

$ touch A.txt aa.txt Z.txt

$ ls

A.txt Z.txt aa.txt

Convert JSONObject to Map

This is what worked for me:

    public static Map<String, Object> toMap(JSONObject jsonobj)  throws JSONException {
        Map<String, Object> map = new HashMap<String, Object>();
        Iterator<String> keys = jsonobj.keys();
        while(keys.hasNext()) {
            String key = keys.next();
            Object value = jsonobj.get(key);
            if (value instanceof JSONArray) {
                value = toList((JSONArray) value);
            } else if (value instanceof JSONObject) {
                value = toMap((JSONObject) value);
            }   
            map.put(key, value);
        }   return map;
    }

    public static List<Object> toList(JSONArray array) throws JSONException {
        List<Object> list = new ArrayList<Object>();
        for(int i = 0; i < array.length(); i++) {
            Object value = array.get(i);
            if (value instanceof JSONArray) {
                value = toList((JSONArray) value);
            }
            else if (value instanceof JSONObject) {
                value = toMap((JSONObject) value);
            }
            list.add(value);
        }   return list;
}

Most of this is from this question: How to convert JSONObject to new Map for all its keys using iterator java

Python Remove last char from string and return it

I decided to go with a for loop and just avoid the item in question, is it an acceptable alternative?

new = ''
for item in str:
    if item == str[n]:
        continue
    else:
        new += item

What is the difference between function and procedure in PL/SQL?

In the few words - function returns something. You can use function in SQL query. Procedure is part of code to do something with data but you can not invoke procedure from query, you have to run it in PL/SQL block.

How can I display two div in one line via css inline property

use inline-block instead of inline. Read more information here about the difference between inline and inline-block.

.inline { 
display: inline-block; 
border: 1px solid red; 
margin:10px;
}

DEMO

Is it possible to have a custom facebook like button?

It's possible with a lot of work.

Basically, you have to post likes action via the Open Graph API. Then, you can add a custom design to your like button.

But then, you''ll need to keep track yourself of the likes so a returning user will be able to unlike content he liked previously.

Plus, you'll need to ask user to log into your app and ask them the publish_action permission.

All in all, if you're doing this for an application, it may worth it. For a website where you basically want user to like articles, then this is really to much.

Also, consider that you increase your drop-off rate each time you ask user a permission via a Facebook login.

If you want to see an example, I've recently made an app using the open graph like button, just hover on some photos in the mosaique to see it

Html.DropDownList - Disabled/Readonly

<script type="text/javascript">
$(function () {
        $(document) .ajaxStart(function () {
                $("#dropdownID").attr("disabled", "disabled");
            })
            .ajaxStop(function () {
                $("#dropdownID").removeAttr("disabled");

            });

});
</script>

What is Vim recording and how can it be disabled?

You start recording by q<letter> and you can end it by typing q again.

Recording is a really useful feature of Vim.

It records everything you type. You can then replay it simply by typing @<letter>. Record search, movement, replacement...

One of the best feature of Vim IMHO.

Connect Android Studio with SVN

There is a "Enable Version Control Integration..." option from the VCS popup (control V). Until you do this and select a VCS the VCS system context menus do not show up and the VCS features are not fully integrated. Not sure why this is so hidden?

Enable Version Control Integration

How to install JSTL? The absolute uri: http://java.sun.com/jstl/core cannot be resolved

I had the same issue , I am using eclipse, just in case others experience the same issue:
In eclipse double click the tomcat server,
stop the server
untick the "server modules without publishing"
start the server.

enter image description here

Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JDBC_DBO]]

server.xml is created when you publish a project.Now If you add more dependency later then server.xml will not be able to catch it until and unless it is refreshed again. Sometimes you need to rebuild context/config file also. First you try to clean the work directory.If it doesn't work then delete server and Server folder,then reconfigure those two.

No content to map due to end-of-input jackson parser

I could fix this error. In my case, the problem was at client side. By mistake I did not close the stream that I was writing to server. I closed stream and it worked fine. Even the error sounds like server was not able to identify the end-of-input.

OutputStream out = new BufferedOutputStream(urlConnection.getOutputStream());
out.write(jsonstring.getBytes());
out.close() ; //This is what I did

How print out the contents of a HashMap<String, String> in ascending order based on its values?

You can use a list of the entry set rather than the key set and it is a more natural choice given you are sorting based on the value. This avoids a lot of unneeded lookups in the sorting and printing of the entries.

Map<String, String> map = ...
List<Map.Entry<String, String>> listOfEntries = new ArrayList<Map.Entry<String, String>>(map.entrySet());
Collections.sort(listOfEntries, new SortByValueComparator());
for(Map.Entry<String, String> entry: listOfEntries)
   System.out.println(entry);

static class SortByValueComparator implements Comparator<Map.Entry<String, String>> {
   public int compareTo(Map.Entry<String, String> e1, Map.Entry<String, String> e2) {
       return e1.getValue().compateTo(e2.getValue());
   }
}

How to set different colors in HTML in one statement?

_x000D_
_x000D_
.rainbow {_x000D_
  background-image: -webkit-gradient( linear, left top, right top, color-stop(0, #f22), color-stop(0.15, #f2f), color-stop(0.3, #22f), color-stop(0.45, #2ff), color-stop(0.6, #2f2),color-stop(0.75, #2f2), color-stop(0.9, #ff2), color-stop(1, #f22) );_x000D_
  background-image: gradient( linear, left top, right top, color-stop(0, #f22), color-stop(0.15, #f2f), color-stop(0.3, #22f), color-stop(0.45, #2ff), color-stop(0.6, #2f2),color-stop(0.75, #2f2), color-stop(0.9, #ff2), color-stop(1, #f22) );_x000D_
  color:transparent;_x000D_
  -webkit-background-clip: text;_x000D_
  background-clip: text;_x000D_
}
_x000D_
<h2><span class="rainbow">Rainbows are colorful and scalable and lovely</span></h2>
_x000D_
_x000D_
_x000D_

How to get name of the computer in VBA?

Looks like I'm late to the game, but this is a common question...

This is probably the code you want.

Please note that this code is in the public domain, from Usenet, MSDN, and the Excellerando blog.

Public Function ComputerName() As String
'' Returns the host name

'' Uses late-binding: bad for performance and stability, useful for 
'' code portability. The correct declaration is:

'   Dim objNetwork  As IWshRuntimeLibrary.WshNetwork
'   Set objNetwork = New IWshRuntimeLibrary.WshNetwork

    Dim objNetwork As Object
    Set objNetwork = CreateObject("WScript.Network")

    ComputerName = objNetwork.ComputerName
    
    Set objNetwork = Nothing

End Function

You'll probably need this, too:

Public Function UserName(Optional WithDomain As Boolean = False) As String
'' Returns the user's network name

'' Uses late-binding: bad for performance and stability, useful for
'' code portability. The correct declaration is:

'   Dim objNetwork  As IWshRuntimeLibrary.WshNetwork
'   Set objNetwork = New IWshRuntimeLibrary.WshNetwork


    Dim objNetwork As Object
    Set objNetwork = CreateObject("WScript.Network")

    If WithDomain Then
        UserName = objNetwork.UserDomain & "\" & objNetwork.UserName
    Else
        UserName = objNetwork.UserName
    End If
    
    Set objNetwork = Nothing

End Function