Programs & Examples On #Visual sourcesafe plugin

how to create virtual host on XAMPP

Add this Code in C:\xampp\apache\conf\extra\httpd-vhosts.conf

<VirtualHost *:80>
DocumentRoot "C:/xampp/htdocs"
ServerName qa-staging.com
ServerAlias www.qa-staging.com
<Directory "c:/xampp/htdocs">
Order allow,deny
Allow from all
</Directory>
</VirtualHost>

Now Add your virtual host name in bellow file.

C:\Windows\System32\drivers\etc\hosts

127.0.0.1 qa-staging.com

If you are not able to save this code in host file then right click on notpad select Run as administrator and then you can able to save your custom code now restart your XAMP

GitLab remote: HTTP Basic: Access denied and fatal Authentication

Open command prompt as administrator then run this command:

git config --system --unset credential.helper

vertical & horizontal lines in matplotlib

The pyplot functions you are calling, axhline() and axvline() draw lines that span a portion of the axis range, regardless of coordinates. The parameters xmin or ymin use value 0.0 as the minimum of the axis and 1.0 as the maximum of the axis.

Instead, use plt.plot((x1, x2), (y1, y2), 'k-') to draw a line from the point (x1, y1) to the point (x2, y2) in color k. See pyplot.plot.

libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

If some one came here after expo eject then below steps will help.

  1. Do, expo start in your terminal
  2. Go to iOS/ and install pod using pod install
  3. Run the build via Xcode.

Binary numbers in Python

Not sure if helpful, but I leave my solution here:

class Solution:
    # @param A : string
    # @param B : string
    # @return a strings
    def addBinary(self, A, B):
        num1 = bin(int(A, 2))
        num2 = bin(int(B, 2))
        bin_str = bin(int(num1, 2)+int(num2, 2))
        b_index = bin_str.index('b')
        return bin_str[b_index+1:]

s = Solution()
print(s.addBinary("11", "100"))

ng-if, not equal to?

That's all unnecessary logic in partials, reduce it to something like this and process your data in controller/service where it should be

<div ng-repeat="details in myDataSet">

    <p>{{ details.Name }}</p>
    <p>{{ details.DOB  }}</p>
    <p>{{details.Payment[0].StatusName}}</p>
    <p>{{ details.Gender}}</p>

</div>

JS:

angular.forEach(myDataSet.Payment, function (payment) {
  if(payment.Status === 0){
    payment.StatusName = 'No Payment';
  } else if(payment.Status === 1 || payment.Status === 2){
    payment.StatusName = 'Late';
  } else if(payment.Status === 3 || payment.Status === 4 || payment.Status === 5){
    payment.StatusName = 'Some payment made';
  } else if(payment.Status === 6){
    payment.StatusName = 'Late and further taken out';
  }else{
    payment.StatusName = 'Error';
  }
})

How to read a CSV file into a .NET Datatable

We always used to use the Jet.OLEDB driver, until we started going to 64 bit applications. Microsoft has not and will not release a 64 bit Jet driver. Here's a simple solution we came up with that uses File.ReadAllLines and String.Split to read and parse the CSV file and manually load a DataTable. As noted above, it DOES NOT handle the situation where one of the column values contains a comma. We use this mostly for reading custom configuration files - the nice part about using CSV files is that we can edit them in Excel.

string CSVFilePathName = @"C:\test.csv";
string[] Lines = File.ReadAllLines(CSVFilePathName);
string[] Fields;
Fields = Lines[0].Split(new char[] { ',' });
int Cols = Fields.GetLength(0);
DataTable dt = new DataTable();
//1st row must be column names; force lower case to ensure matching later on.
for (int i = 0; i < Cols; i++)
    dt.Columns.Add(Fields[i].ToLower(), typeof(string));
DataRow Row;
for (int i = 1; i < Lines.GetLength(0); i++)
{
    Fields = Lines[i].Split(new char[] { ',' });
    Row = dt.NewRow();
    for (int f = 0; f < Cols; f++)
        Row[f] = Fields[f];
    dt.Rows.Add(Row);
}

How to highlight a current menu item?

None of the above directive suggestions were useful to me. If you have a bootstrap navbar like this

<ul class="nav navbar-nav">
    <li><a ng-href="#/">Home</a></li>
    <li><a ng-href="#/about">About</a></li>
  ...
</ul>

(that could be a $ yo angular startup) then you want to add .active to the parent <li> element class list, not the element itself; i.e <li class="active">..</li>. So I wrote this :

.directive('setParentActive', ['$location', function($location) {
  return {
    restrict: 'A',
    link: function(scope, element, attrs, controller) {
      var classActive = attrs.setParentActive || 'active',
          path = attrs.ngHref.replace('#', '');
      scope.location = $location;
      scope.$watch('location.path()', function(newPath) {
        if (path == newPath) {
          element.parent().addClass(classActive);
        } else {
          element.parent().removeClass(classActive);
        }
      })
    }
  }
}])

usage set-parent-active; .active is default so not needed to be set

<li><a ng-href="#/about" set-parent-active>About</a></li>

and the parent <li> element will be .active when the link is active. To use an alternative .active class like .highlight, simply

<li><a ng-href="#/about" set-parent-active="highlight">About</a></li>

Which to use <div class="name"> or <div id="name">?

  • the Id selector is used when referring to a single unique element.
  • The Class selector referrers a group of elements.

For example, if you have a multiple buttons that look the same, you should use class="mybutton" to have consistent styling.

In terms of performance:

CSS selectors are matched from right to left.

Therefore, .myClass should be "faster" than #myID because it misses out testing.

The performance speed is negligible for normally sized pages and you will probably never notice a difference so it's mostly just about convention.

Here is more info on why css is browsers match css selectors from right to left

bootstrap 3 wrap text content within div for horizontal alignment

Now Update word-wrap is replace by :

overflow-wrap:break-word;

Compatible old navigator and css 3 it's good alternative !

it's evolution of word-wrap ( since 2012... )

See more information : https://www.w3.org/TR/css-text-3/#overflow-wrap

See compatibility full : http://caniuse.com/#search=overflow-wrap

Singleton with Arguments in Java

Surprised that no one mentioned how a logger is created/retrieved. For example, below shows how Log4J logger is retrieved.

// Retrieve a logger named according to the value of the name parameter. If the named logger already exists, then the existing instance will be returned. Otherwise, a new instance is created.
public static Logger getLogger(String name)

There are some levels of indirections, but the key part is below method which pretty much tells everything about how it works. It uses a hash table to store the exiting loggers and the key is derived from name. If the logger doesn't exist for a give name, it uses a factory to create the logger and then adds it to the hash table.

69   Hashtable ht;
...
258  public
259  Logger getLogger(String name, LoggerFactory factory) {
260    //System.out.println("getInstance("+name+") called.");
261    CategoryKey key = new CategoryKey(name);
262    // Synchronize to prevent write conflicts. Read conflicts (in
263    // getChainedLevel method) are possible only if variable
264    // assignments are non-atomic.
265    Logger logger;
266
267    synchronized(ht) {
268      Object o = ht.get(key);
269      if(o == null) {
270        logger = factory.makeNewLoggerInstance(name);
271        logger.setHierarchy(this);
272        ht.put(key, logger);
273        updateParents(logger);
274        return logger;
275      } else if(o instanceof Logger) {
276        return (Logger) o;
277      } 
...

How can I make the browser wait to display the page until it's fully loaded?

Although this is not always a good idea, you're free to decide if you really want to do that. There are some different ways to do it, and I found a simple example here:

http://www.reconn.us/content/view/37/47/

Probably not the best one, but it should help you develop your own solution. Good luck.

Get key by value in dictionary

def get_Value(dic,value):
    for name in dic:
        if dic[name] == value:
            del dic[name]
            return name

Upload file to SFTP using PowerShell

There isn't currently a built-in PowerShell method for doing the SFTP part. You'll have to use something like psftp.exe or a PowerShell module like Posh-SSH.

Here is an example using Posh-SSH:

# Set the credentials
$Password = ConvertTo-SecureString 'Password1' -AsPlainText -Force
$Credential = New-Object System.Management.Automation.PSCredential ('root', $Password)

# Set local file path, SFTP path, and the backup location path which I assume is an SMB path
$FilePath = "C:\FileDump\test.txt"
$SftpPath = '/Outbox'
$SmbPath = '\\filer01\Backup'

# Set the IP of the SFTP server
$SftpIp = '10.209.26.105'

# Load the Posh-SSH module
Import-Module C:\Temp\Posh-SSH

# Establish the SFTP connection
$ThisSession = New-SFTPSession -ComputerName $SftpIp -Credential $Credential

# Upload the file to the SFTP path
Set-SFTPFile -SessionId ($ThisSession).SessionId -LocalFile $FilePath -RemotePath $SftpPath

#Disconnect all SFTP Sessions
Get-SFTPSession | % { Remove-SFTPSession -SessionId ($_.SessionId) }

# Copy the file to the SMB location
Copy-Item -Path $FilePath -Destination $SmbPath

Some additional notes:

  • You'll have to download the Posh-SSH module which you can install to your user module directory (e.g. C:\Users\jon_dechiro\Documents\WindowsPowerShell\Modules) and just load using the name or put it anywhere and load it like I have in the code above.
  • If having the credentials in the script is not acceptable you'll have to use a credential file. If you need help with that I can update with some details or point you to some links.
  • Change the paths, IPs, etc. as needed.

That should give you a decent starting point.

Design Android EditText to show error message as described by google

If anybody still facing the error with using google's design library as mentioned in the answer then, please use this as commented by @h_k which is -

Instead of calling setError on TextInputLayout, You might be using setError on EditText itself.

how to show calendar on text box click in html

try to use jquery-ui

<script src="http://code.jquery.com/ui/1.10.1/jquery-ui.js"></script>

<script>   
    $(function() {
         $( "#calendar" ).datepicker();   
    }); 
</script>

<p>Calendar: <input type="text" id="calendar" /></p>

more

Extract hostname name from string

Here's the jQuery one-liner:

$('<a>').attr('href', url).prop('hostname');

Twitter Bootstrap: Print content of modal window

_x000D_
_x000D_
@media print{_x000D_
 body{_x000D_
  visibility: hidden; /* no print*/_x000D_
 }_x000D_
 .print{_x000D_
  _x000D_
  visibility:visible; /*print*/_x000D_
 }_x000D_
}
_x000D_
<body>_x000D_
  <div class="noprint"> <!---no print--->_x000D_
  <div class="noprint"> <!---no print--->_x000D_
  <div class="print">   <!---print--->_x000D_
  <div class="print">   <!---print--->_x000D_
_x000D_
_x000D_
</body>
_x000D_
_x000D_
_x000D_

PHP PDO returning single row

Did you try:

$DBH = new PDO( "connection string goes here" );
$row = $DBH->query( "select figure from table1" )->fetch();
echo $row["figure"];
$DBH = null;

How to grep a string in a directory and all its subdirectories?

grep -r -e string directory

-r is for recursive; -e is optional but its argument specifies the regex to search for. Interestingly, POSIX grep is not required to support -r (or -R), but I'm practically certain that System V grep did, so in practice they (almost) all do. Some versions of grep support -R as well as (or conceivably instead of) -r; AFAICT, it means the same thing.

Verify External Script Is Loaded

If the script creates any variables or functions in the global space you can check for their existance:

External JS (in global scope) --

var myCustomFlag = true;

And to check if this has run:

if (typeof window.myCustomFlag == 'undefined') {
    //the flag was not found, so the code has not run
    $.getScript('<external JS>');
}

Update

You can check for the existence of the <script> tag in question by selecting all of the <script> elements and checking their src attributes:

//get the number of `<script>` elements that have the correct `src` attribute
var len = $('script').filter(function () {
    return ($(this).attr('src') == '<external JS>');
}).length;

//if there are no scripts that match, the load it
if (len === 0) {
    $.getScript('<external JS>');
}

Or you can just bake this .filter() functionality right into the selector:

var len = $('script[src="<external JS>"]').length;

What's the difference between IFrame and Frame?

The only reasons I can think of are actually in the wiki article you referenced to mention a couple...

"The "Verified by Visa" system has drawn some criticism, since it is hard for users to differentiate between the legitimate Verified by Visa pop-up window or inline frame, and a fraudulent phishing site."

"as of 2008, most web browsers do not provide a simple way to check the security certificate for the contents of an iframe"

If you read the Criticism section in the article it details all the potential security flaws.

Otherwise the only difference is the fact that an IFrame is an inline frame and a Frame is part of a Frameset. Which means more layout problems than anything else!

Joda DateTime to Timestamp conversion

I've solved this problem in this way.

String dateUTC = rs.getString("date"); //UTC
DateTime date;
DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss.SSS").withZoneUTC();
date = dateTimeFormatter.parseDateTime(dateUTC);

In this way you ignore the server TimeZone forcing your chosen TimeZone.

How to create a directory if it doesn't exist using Node.js?

fs.exist() is deprecated. So I have used fs.stat() to check the directory status. If the directory does not exist fs.stat() throw an error with message like 'no such file or directory'. Then I have created a directory.

const fs = require('fs').promises;
    
const dir = './dir';
fs.stat(dir).catch(async (err) => {
  if (err.message.includes('no such file or directory')) {
    await fs.mkdir(dir);
  }
});

Open source face recognition for Android

Here are some links that I found on face recognition libraries.

Image Identification links:

Run all SQL files in a directory

You can create a single script that calls all the others.

Put the following into a batch file:

@echo off
echo.>"%~dp0all.sql"
for %%i in ("%~dp0"*.sql) do echo @"%%~fi" >> "%~dp0all.sql"

When you run that batch file it will create a new script named all.sql in the same directory where the batch file is located. It will look for all files with the extension .sql in the same directory where the batch file is located.

You can then run all scripts by using sqlplus user/pwd @all.sql (or extend the batch file to call sqlplus after creating the all.sql script)

Using Image control in WPF to display System.Drawing.Bitmap

According to http://khason.net/blog/how-to-use-systemdrawingbitmap-hbitmap-in-wpf/

   [DllImport("gdi32")]
   static extern int DeleteObject(IntPtr o);

   public static BitmapSource loadBitmap(System.Drawing.Bitmap source)
   {
       IntPtr ip = source.GetHbitmap();
       BitmapSource bs = null;
       try
       {
           bs = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(ip, 
              IntPtr.Zero, Int32Rect.Empty, 
              System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
       }
       finally
       {
           DeleteObject(ip);
       }

       return bs;
   }

It gets System.Drawing.Bitmap (from WindowsBased) and converts it into BitmapSource, which can be actually used as image source for your Image control in WPF.

image1.Source = YourUtilClass.loadBitmap(SomeBitmap);

How do I convert an NSString value to NSData?

First off, you should use dataUsingEncoding: instead of going through UTF8String. You only use UTF8String when you need a C string in that encoding.

Then, for UTF-16, just pass NSUnicodeStringEncoding instead of NSUTF8StringEncoding in your dataUsingEncoding: message.

Failed to allocate memory: 8

In my case, changin screen resolution from WVGA720 to WSVGA works for me.

How do I tell if an object is a Promise?

Here's my original answer, which has since been ratified in the spec as the way to test for a promise:

Promise.resolve(obj) == obj

This works because the algorithm explicitly demands that Promise.resolve must return the exact object passed in if and only if it is a promise by the definition of the spec.

I have another answer here, which used to say this, but I changed it to something else when it didn't work with Safari at that time. That was a year ago, and this now works reliably even in Safari.

I would have edited my original answer, except that felt wrong, given that more people by now have voted for the altered solution in that answer than the original. I believe this is the better answer, and I hope you agree.

How to compare two tags with git?

If source code is on Github, you can use their comparing tool: https://help.github.com/articles/comparing-commits-across-time/

MySQL combine two columns and add into a new column

Add new column to your table and perfrom the query:

UPDATE tbl SET combined = CONCAT(zipcode, ' - ', city, ', ', state)

how to convert object into string in php

Use the casting operator (string)$yourObject;

Throwing exceptions in a PHP Try Catch block

Throw needs an object instantiated by \Exception. Just the $e catched can play the trick.

throw $e

How to check if a string contains a specific text

Empty strings are falsey, so you can just write:

if ($a) {
    echo 'text';
}

Although if you're asking if a particular substring exists in that string, you can use strpos() to do that:

if (strpos($a, 'some text') !== false) {
    echo 'text';
}

Change all files and folders permissions of a directory to 644/755

The shortest one I could come up with is:

chmod -R a=r,u+w,a+X /foo

which works on GNU/Linux, and I believe on Posix in general (from my reading of: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/chmod.html).

What this does is:

  1. Set file/directory to r__r__r__ (0444)
  2. Add w for owner, to get rw_r__r__ (0644)
  3. Set execute for all if a directory (0755 for dir, 0644 for file).

Importantly, the step 1 permission clears all execute bits, so step 3 only adds back execute bits for directories (never files). In addition, all three steps happen before a directory is recursed into (so this is not equivalent to e.g.

chmod -R a=r /foo
chmod -R u+w /foo
chmod -R a+X /foo

since the a=r removes x from directories, so then chmod can't recurse into them.)

Populating a ListView using an ArrayList?

Here's an example of how you could implement a list view:

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //We have our list view
    final ListView dynamic = findViewById(R.id.dynamic);

    //Create an array of elements
    final ArrayList<String> classes = new ArrayList<>();
    classes.add("Data Structures");
    classes.add("Assembly Language");
    classes.add("Calculus 3");
    classes.add("Switching Systems");
    classes.add("Analysis Tools");

    //Create adapter for ArrayList
    final ArrayAdapter<String> adapter = new ArrayAdapter<>(this,android.R.layout.simple_list_item_1, classes);

    //Insert Adapter into List
    dynamic.setAdapter(adapter);

    //set click functionality for each list item
    dynamic.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Log.i("User clicked ", classes.get(position));
        }
    });



}

Capitalize the first letter of both words in a two word string

There is a build-in base-R solution for title case as well:

tools::toTitleCase("demonstrating the title case")
## [1] "Demonstrating the Title Case"

or

library(tools)
toTitleCase("demonstrating the title case")
## [1] "Demonstrating the Title Case"

Powershell: How can I stop errors from being displayed in a script?

You have a couple of options. The easiest involve using the ErrorAction settings.

-Erroraction is a universal parameter for all cmdlets. If there are special commands you want to ignore you can use -erroraction 'silentlycontinue' which will basically ignore all error messages generated by that command. You can also use the Ignore value (in PowerShell 3+):

Unlike SilentlyContinue, Ignore does not add the error message to the $Error automatic variable.

If you want to ignore all errors in a script, you can use the system variable $ErrorActionPreference and do the same thing: $ErrorActionPreference= 'silentlycontinue'

See about_CommonParameters for more info about -ErrorAction. See about_preference_variables for more info about $ErrorActionPreference.

How to update an object in a List<> in C#

You can do somthing like :

if (product != null) {
    var products = Repository.Products;
    var indexOf = products.IndexOf(products.Find(p => p.Id == product.Id));
    Repository.Products[indexOf] = product;
    // or 
    Repository.Products[indexOf].prop = product.prop;
}

Xcode - How to fix 'NSUnknownKeyException', reason: … this class is not key value coding-compliant for the key X" error?

In my case, this was caused by referencing the wrong Nib:

BMTester *viewController = [[BMTester alloc] initWithNibName:@"WrongNibName" bundle:nil];

How to check if a variable is not null?

The two conditional statements you list here are not better than one another. Your usage depends on the situation. You have a typo by the way in the 2nd example. There should be only one equals sign after the exclamation mark.

The 1st example determines if the value in myVar is true and executes the code inside of the {...}

The 2nd example evaluates if myVar does not equal null and if that case is true it will execute your code inside of the {...}

I suggest taking a look into conditional statements for more techniques. Once you are familiar with them, you can decide when you need them.

Git - What is the difference between push.default "matching" and "simple"

Git v2.0 Release Notes

Backward compatibility notes

When git push [$there] does not say what to push, we have used the traditional "matching" semantics so far (all your branches were sent to the remote as long as there already are branches of the same name over there). In Git 2.0, the default is now the "simple" semantics, which pushes:

  • only the current branch to the branch with the same name, and only when the current branch is set to integrate with that remote branch, if you are pushing to the same remote as you fetch from; or

  • only the current branch to the branch with the same name, if you are pushing to a remote that is not where you usually fetch from.

You can use the configuration variable "push.default" to change this. If you are an old-timer who wants to keep using the "matching" semantics, you can set the variable to "matching", for example. Read the documentation for other possibilities.

When git add -u and git add -A are run inside a subdirectory without specifying which paths to add on the command line, they operate on the entire tree for consistency with git commit -a and other commands (these commands used to operate only on the current subdirectory). Say git add -u . or git add -A . if you want to limit the operation to the current directory.

git add <path> is the same as git add -A <path> now, so that git add dir/ will notice paths you removed from the directory and record the removal. In older versions of Git, git add <path> used to ignore removals. You can say git add --ignore-removal <path> to add only added or modified paths in <path>, if you really want to.

"query function not defined for Select2 undefined error"

Covered in this google group thread

The problem was because of the extra div that was being added by the select2. Select2 had added new div with class "select2-container form-select" to wrap the select created. So the next time i loaded the function, the error was being thrown as select2 was being attached to the div element. I changed my selector...

Prefix select2 css identifier with specific tag name "select":

$('select.form-select').select2();

org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'customerService' is defined

Please make sure that your applicationContext.xml file is loaded by specifying it in your web.xml file:

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>

How to round an image with Glide library?

implementation 'com.github.bumptech.glide:glide:4.8.0'
annotationProcessor 'com.github.bumptech.glide:compiler:4.8.0'


RequestOptions options=new RequestOptions();
        options.centerCrop().placeholder(getResources().getDrawable(R.drawable.user_placeholder));
        Glide.with(this)
                .load(preferenceSingleTon.getImage())
                .apply(options)
                .into(ProfileImage);

Event listener for when element becomes visible?

As @figha says, if this is your own web page, you should just run whatever you need to run after you make the element visible.

However, for the purposes of answering the question (and anybody making Chrome or Firefox Extensions, where this is a common use case), Mutation Summary and Mutation Observer will allow DOM changes to trigger events.

For example, triggering an event for a elements with data-widget attribute being added to the DOM. Borrowing this excellent example from David Walsh's blog:

var observer = new MutationObserver(function(mutations) {
    // For the sake of...observation...let's output the mutation to console to see how this all works
    mutations.forEach(function(mutation) {
        console.log(mutation.type);
    });    
});

// Notify me of everything!
var observerConfig = {
    attributes: true, 
    childList: true, 
    characterData: true 
};

// Node, config
// In this case we'll listen to all changes to body and child nodes
var targetNode = document.body;
observer.observe(targetNode, observerConfig);

Responses include added, removed, valueChanged and more. valueChanged includes all attributes, including display etc.

How to set encoding in .getJSON jQuery

Use this function to regain the utf-8 characters

function decode_utf8(s) { 
  return decodeURIComponent(escape(s)); 
}

Example: var new_Str=decode_utf8(str);

Python 3.4.0 with MySQL database

Install pip:

apt-get install pip

For acess MySQL from Python, install:

pip3 install mysqlclient

Sites not accepting wget user agent header

You need to set both the user-agent and the referer:

 wget  --header="Accept: text/html" --user-agent="Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:21.0) Gecko/20100101 Firefox/21.0" --referrer  connect.wso2.com http://dist.wso2.org/products/carbon/4.2.0/wso2carbon-4.2.0.zip

Find unused code

The truth is that the tool can never give you a 100% certain answer, but coverage tool can give you a pretty good run for the money.

If you count with comprehensive unit test suite, than you can use test coverage tool to see exactly what lines of code were not executed during the test run. You will still need to analyze the code manually: either eliminate what you consider dead code or write test to improve test coverage.

One such tool is NCover, with open source precursor on Sourceforge. Another alternative is PartCover.

Check out this answer on stackoverflow.

Does Ruby have a string.startswith("abc") built in method?

If this is for a non-Rails project, I'd use String#index:

"foobar".index("foo") == 0  # => true

What is a Sticky Broadcast?

If an Activity calls onPause with a normal broadcast, receiving the Broadcast can be missed. A sticky broadcast can be checked after it was initiated in onResume.

Update 6/23/2020

Sticky broadcasts are deprecated.

See sendStickyBroadcast documentation.

This method was deprecated in API level 21.

Sticky broadcasts should not be used. They provide no security (anyone can access them), no protection (anyone can modify them), and many other problems. The recommended pattern is to use a non-sticky broadcast to report that something has changed, with another mechanism for apps to retrieve the current value whenever desired.

Implement

Intent intent = new Intent("some.custom.action");
intent.putExtra("some_boolean", true);
sendStickyBroadcast(intent);

Resources

How to add smooth scrolling to Bootstrap's scroll spy function

If you have a fixed navbar, you'll need something like this.

Taking from the best of the above answers and comments...

$(".bs-js-navbar-scrollspy li a[href^='#']").on('click', function(event) {
  var target = this.hash;

  event.preventDefault();

  var navOffset = $('#navbar').height();

  return $('html, body').animate({
    scrollTop: $(this.hash).offset().top - navOffset
  }, 300, function() {
    return window.history.pushState(null, null, target);
  });
});

First, in order to prevent the "undefined" error, store the hash to a variable, target, before calling preventDefault(), and later reference that stored value instead, as mentioned by pupadupa.

Next. You cannot use window.location.hash = target because it sets the url and the location simultaneously rather than separately. You will end up having the location at the beginning of the element whose id matches the href... but covered by your fixed top navbar.

In order to get around this, you set your scrollTop value to the vertical scroll location value of the target minus the height of your fixed navbar. Directly targeting that value maintains smooth scrolling, instead of adding an adjustment afterwards, and getting unprofessional-looking jitters.

You will notice the url doesn't change. To set this, use return window.history.pushState(null, null, target); instead, to manually add the url to the history stack.

Done!

Other notes:

1) using the .on method is the latest (as of Jan 2015) jquery method that is better than .bind or .live, or even .click for reasons I'll leave to you to find out.

2) the navOffset value can be within the function or outside, but you will probably want it outside, as you may very well reference that vertical space for other functions / DOM manipulations. But I left it inside to make it neatly into one function.

Oracle Differences between NVL and Coalesce

NVL and COALESCE are used to achieve the same functionality of providing a default value in case the column returns a NULL.

The differences are:

  1. NVL accepts only 2 arguments whereas COALESCE can take multiple arguments
  2. NVL evaluates both the arguments and COALESCE stops at first occurrence of a non-Null value.
  3. NVL does a implicit datatype conversion based on the first argument given to it. COALESCE expects all arguments to be of same datatype.
  4. COALESCE gives issues in queries which use UNION clauses. Example below
  5. COALESCE is ANSI standard where as NVL is Oracle specific.

Examples for the third case. Other cases are simple.

select nvl('abc',10) from dual; would work as NVL will do an implicit conversion of numeric 10 to string.

select coalesce('abc',10) from dual; will fail with Error - inconsistent datatypes: expected CHAR got NUMBER

Example for UNION use-case

SELECT COALESCE(a, sysdate) 
from (select null as a from dual 
      union 
      select null as a from dual
      );

fails with ORA-00932: inconsistent datatypes: expected CHAR got DATE

SELECT NVL(a, sysdate) 
from (select null as a from dual 
      union 
      select null as a from dual
      ) ;

succeeds.

More information : http://www.plsqlinformation.com/2016/04/difference-between-nvl-and-coalesce-in-oracle.html

How do I count the number of rows and columns in a file using bash?

If counting number of columns in the first is enough, try the following:

awk -F'\t' '{print NF; exit}' myBigFile.tsv

where \t is column delimiter.

Is it possible to get a list of files under a directory of a website? How?

If a website's directory does NOT have an "index...." file, AND .htaccess has NOT been used to block access to the directory itself, then Apache will create an "index of" page for that directory. You can save that page, and its icons, using "Save page as..." along with the "Web page, complete" option (Firefox example). If you own the website, temporarily rename any "index...." file, and reference the directory locally. Then restore your "index...." file.

PHP json_decode() returns NULL with valid JSON?

The most important thing to remember, when you get a NULL result from JSON data that is valid is to use the following command:

json_last_error_msg();

Ie.

var_dump(json_last_error_msg());
string(53) "Control character error, possibly incorrectly encoded"

You then fix that with:

$new_json = preg_replace('/[[:cntrl:]]/', '', $json);

Maximum length for MySQL type text

TINYTEXT 256 bytes
TEXT 65,535 bytes ~64kb
MEDIUMTEXT 16,777,215 bytes ~16MB
LONGTEXT 4,294,967,295 bytes ~4GB

TINYTEXT is a string data type that can store up to to 255 characters.

TEXT is a string data type that can store up to 65,535 characters. TEXT is commonly used for brief articles.

LONGTEXT is a string data type with a maximum length of 4,294,967,295 characters. Use LONGTEXT if you need to store large text, such as a chapter of a novel.

Error: 10 $digest() iterations reached. Aborting! with dynamic sortby predicate

I have another example of something that caused this. Hopefully it helps for future reference. I'm using AngularJS 1.4.1.

I had this markup with multiple calls to a custom directive:

<div ng-controller="SomeController">
    <myDirective data="myData.Where('IsOpen',true)"></myDirective>
    <myDirective data="myData.Where('IsOpen',false)"></myDirective>
</div>

myData is an array and Where() is an extension method that iterates over the array returning a new array containing any items from the original where the IsOpen property matches the bool value in the second parameter.

In the controller I set $scope.data like this:

DataService.getData().then(function(results){
    $scope.data = results;
});

Calling the Where() extension method from the directive like in the above markup was the problem. To fix this issue I moved the call to the extension method into the controller instead of the markup:

<div ng-controller="SomeController">
    <myDirective data="openData"></myDirective>
    <myDirective data="closedData"></myDirective>
</div>

and the new controller code:

DataService.getData().then(function(results){
    $scope.openData = results.Where('IsOpen',true);
    $scope.closedData = results.Where('IsOpen',false);
});

Removing all script tags from html with JS Regular Expression

Here are a variety of shell scripts you can use to strip out different elements.

# doctype
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/<\!DOCTYPE\s\+html[^>]*>/<\!DOCTYPE html>/gi" {} \;

# meta charset
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/<meta[^>]*content=[\"'][^\"']*utf-8[\"'][^>]*>/<meta charset=\"utf-8\">/gi" {} \;

# script text/javascript
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<script[^>]*\)\(\stype=[\"']text\/javascript[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

# style text/css
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<style[^>]*\)\(\stype=[\"']text\/css[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

# html xmlns
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<html[^>]*\)\(\sxmlns=[\"'][^\"']*[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

# html xml:lang
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<html[^>]*\)\(\sxml:lang=[\"'][^\"']*[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

How can I get the source directory of a Bash script from within the script itself?

The top response does not work in all cases...

As I had problems with the BASH_SOURCE with the included 'cd' approach on some very fresh and also on less fresh installed Ubuntu 16.04 (Xenial Xerus) systems when invoking the shell script by means of "sh my_script.sh", I tried out something different that as of now seems to run quite smoothly for my purposes. The approach is a bit more compact in the script and is further much lesser cryptic feeling.

This alternate approach uses the external applications 'realpath' and 'dirname' from the coreutils package. (Okay, not anyone likes the overhead of invoking secondary processes - but when seeing the multi-line scripting for resolving the true object it won't be that bad either having it solve in a single binary usage.)

So let’s see one example of those alternate solution for the described task of querying the true absolute path to a certain file:

SCRIPT=`realpath -s $0`
SCRIPTPATH=`dirname $SCRIPT`

Or when having the chance of using paths with spaces (or maybe other special characters):

SCRIPT=`realpath -s "$0"`
SCRIPTPATH=`dirname "$SCRIPT"`

Indeed, if you don’t need the value of the SCRIPT variable then you might be able to merge this two-liner into even a single line. But why really shall you spend the effort for this?

What is a semaphore?

So imagine everyone is trying to go to the bathroom and there's only a certain number of keys to the bathroom. Now if there's not enough keys left, that person needs to wait. So think of semaphore as representing those set of keys available for bathrooms (the system resources) that different processes (bathroom goers) can request access to.

Now imagine two processes trying to go to the bathroom at the same time. That's not a good situation and semaphores are used to prevent this. Unfortunately, the semaphore is a voluntary mechanism and processes (our bathroom goers) can ignore it (i.e. even if there are keys, someone can still just kick the door open).

There are also differences between binary/mutex & counting semaphores.

Check out the lecture notes at http://www.cs.columbia.edu/~jae/4118/lect/L05-ipc.html.

mysql_fetch_array() expects parameter 1 to be resource problem

You are not doing error checking after the call to mysql_query:

$result = mysql_query("SELECT * FROM student WHERE IDNO=".$_GET['id']);
if (!$result) { // add this check.
    die('Invalid query: ' . mysql_error());
}

In case mysql_query fails, it returns false, a boolean value. When you pass this to mysql_fetch_array function (which expects a mysql result object) we get this error.

SQL - Update multiple records in one query

maybe for someone it will be useful

for Postgresql 9.5 works as a charm

INSERT INTO tabelname(id, col2, col3, col4)
VALUES
    (1, 1, 1, 'text for col4'),
    (DEFAULT,1,4,'another text for col4')
ON CONFLICT (id) DO UPDATE SET
    col2 = EXCLUDED.col2,
    col3 = EXCLUDED.col3,
    col4 = EXCLUDED.col4

this SQL updates existing record and inserts if new one (2 in 1)

How to force addition instead of concatenation in javascript

Your code concatenates three strings, then converts the result to a number.

You need to convert each variable to a number by calling parseFloat() around each one.

total = parseFloat(myInt1) + parseFloat(myInt2) + parseFloat(myInt3);

Runtime error: Could not load file or assembly 'System.Web.WebPages.Razor, Version=3.0.0.0

"Update-Package –reinstall Microsoft.AspNet.WebPages"

Reinstall Microsoft.AspNet.WebPages nuget packages using this command in the package manager console. 100% work!!

How to use andWhere and orWhere in Doctrine?

Here's an example for those who have more complicated conditions and using Doctrine 2.* with QueryBuilder:

$qb->where('o.foo = 1')
   ->andWhere($qb->expr()->orX(
      $qb->expr()->eq('o.bar', 1),
      $qb->expr()->eq('o.bar', 2)
   ))
  ;

Those are expressions mentioned in Czechnology answer.

Input group - two inputs close to each other

I was not content with any of the answers on this page, so I fiddled with this myself for a bit. I came up with the following

_x000D_
_x000D_
angular.module('showcase', []).controller('Ctrl', function() {_x000D_
  var vm = this;_x000D_
  vm.focusParent = function(event) {_x000D_
    angular.element(event.target).parent().addClass('focus');_x000D_
  };_x000D_
_x000D_
  vm.blurParent = function(event) {_x000D_
    angular.element(event.target).parent().removeClass('focus');_x000D_
  };_x000D_
});
_x000D_
.input-merge .col-xs-2,_x000D_
.input-merge .col-xs-4,_x000D_
.input-merge .col-xs-6 {_x000D_
  padding-left: 0;_x000D_
  padding-right: 0;_x000D_
}_x000D_
.input-merge div:first-child .form-control {_x000D_
  border-top-right-radius: 0;_x000D_
  border-bottom-right-radius: 0;_x000D_
}_x000D_
.input-merge div:last-child .form-control {_x000D_
  border-top-left-radius: 0;_x000D_
  border-bottom-left-radius: 0;_x000D_
}_x000D_
.input-merge div:not(:first-child) {_x000D_
  margin-left: -1px;_x000D_
}_x000D_
.input-merge div:not(:first-child):not(:last-child) .form-control {_x000D_
  border-radius: 0;_x000D_
}_x000D_
.focus {_x000D_
  z-index: 2;_x000D_
}
_x000D_
<html ng-app="showcase">_x000D_
_x000D_
<head>_x000D_
  <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>_x000D_
  <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />_x000D_
</head>_x000D_
_x000D_
<body class="container">_x000D_
  <label class="control-label">Person</label>_x000D_
  <div class="input-merge" ng-controller="Ctrl as showCase">_x000D_
    <div class="col-xs-4">_x000D_
      <input class="form-control input-sm" name="initials" type="text" id="initials"_x000D_
             ng-focus="showCase.focusParent($event)" ng-blur="showCase.blurParent($event)"_x000D_
             ng-model="person.initials" placeholder="Initials" />_x000D_
    </div>_x000D_
_x000D_
    <div class="col-xs-2">_x000D_
      <input class="form-control input-sm" name="prefixes" type="text" id="prefixes"_x000D_
             ng-focus="showCase.focusParent($event)" ng-blur="showCase.blurParent($event)"_x000D_
             ng-model="persoon.prefixes" placeholder="Prefixes" />_x000D_
    </div>_x000D_
_x000D_
    <div class="col-xs-6">_x000D_
      <input class="form-control input-sm" name="surname" type="text" id="surname"_x000D_
             ng-focus="showCase.focusParent($event)" ng-blur="showCase.blurParent($event)"_x000D_
             ng-model="persoon.surname" placeholder="Surname" />_x000D_
    </div>_x000D_
  </div>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

With this it is possible to set the width of the individual inputs to your liking. Also a minor issue with the above snippets was that the input looks incomplete when focussed or when it is not valid. I fixed this with some angular code, but you can just as easily do this with jQuery or native javascript or whatever.

The code adds the class .focus to the containing div's, so it can get a higher z-index then the others when the input is focussed.

Get checkbox values using checkbox name using jquery

If you like to get a list of all values of checked checkboxes (e.g. to send them as a list in one AJAX call to the server), you could get that list with:

var list = $("input[name='bla[]']:checked").map(function () {
    return this.value;
}).get();

Returning Month Name in SQL Server Query

for me DATENAME was not accessable due to company restrictions.... but this worked very easy too.

FORMAT(date, 'MMMM') AS month

How to delete specific characters from a string in Ruby?

Do as below using String#tr :

 "((String1))".tr('()', '')
 # => "String1"

Grouping switch statement cases together?

Sure you can.

You can use case x ... y for the range

Example:

#include <iostream.h>
#include <stdio.h>
int main()
{
   int Answer;
   cout << "How many cars do you have?";
   cin >> Answer;
   switch (Answer)                                      
      {
      case 1 ... 4:
         cout << "You need more cars. ";
         break;                                        
      case 5 ... 8:
         cout << "Now you need a house. ";
         break;                                        
      default:
         cout << "What are you? A peace-loving hippie freak? ";
      }
      cout << "\nPress ENTER to continue... " << endl;
      getchar();
      return 0;
}

Make sure you have "-std=c++0x" flag enabled within your compiler

Javascript getElementsByName.value not working

document.getElementsByName("name") will get several elements called by same name . document.getElementsByName("name")[Number] will get one of them. document.getElementsByName("name")[Number].value will get the value of paticular element.

The key of this question is this:
The name of elements is not unique, it is usually used for several input elements in the form.
On the other hand, the id of the element is unique, which is the only definition for a particular element in a html file.

Adding default parameter value with type hint in Python

If you're using typing (introduced in Python 3.5) you can use typing.Optional, where Optional[X] is equivalent to Union[X, None]. It is used to signal that the explicit value of None is allowed . From typing.Optional:

def foo(arg: Optional[int] = None) -> None:
    ...

Difference between git pull and git pull --rebase

Sometimes we have an upstream that rebased/rewound a branch we're depending on. This can be a big problem -- causing messy conflicts for us if we're downstream.

The magic is git pull --rebase

A normal git pull is, loosely speaking, something like this (we'll use a remote called origin and a branch called foo in all these examples):

# assume current checked out branch is "foo"
git fetch origin
git merge origin/foo

At first glance, you might think that a git pull --rebase does just this:

git fetch origin
git rebase origin/foo

But that will not help if the upstream rebase involved any "squashing" (meaning that the patch-ids of the commits changed, not just their order).

Which means git pull --rebase has to do a little bit more than that. Here's an explanation of what it does and how.

Let's say your starting point is this:

a---b---c---d---e  (origin/foo) (also your local "foo")

Time passes, and you have made some commits on top of your own "foo":

a---b---c---d---e---p---q---r (foo)

Meanwhile, in a fit of anti-social rage, the upstream maintainer has not only rebased his "foo", he even used a squash or two. His commit chain now looks like this:

a---b+c---d+e---f  (origin/foo)

A git pull at this point would result in chaos. Even a git fetch; git rebase origin/foo would not cut it, because commits "b" and "c" on one side, and commit "b+c" on the other, would conflict. (And similarly with d, e, and d+e).

What git pull --rebase does, in this case, is:

git fetch origin
git rebase --onto origin/foo e foo

This gives you:

 a---b+c---d+e---f---p'---q'---r' (foo)

You may still get conflicts, but they will be genuine conflicts (between p/q/r and a/b+c/d+e/f), and not conflicts caused by b/c conflicting with b+c, etc.

Answer taken from (and slightly modified):
http://gitolite.com/git-pull--rebase

Command line tool to dump Windows DLL version?

and one way with makecab:

; @echo off
;;goto :end_help
;;setlocal DsiableDelayedExpansion
;;;
;;;
;;; fileinf /l list of full file paths separated with ;
;;; fileinf /f text file with a list of files to be processed ( one on each line )
;;; fileinf /? prints the help
;;;
;;:end_help

; REM Creating a Newline variable (the two blank lines are required!)
; set NLM=^


; set NL=^^^%NLM%%NLM%^%NLM%%NLM%
; if "%~1" equ "/?" type "%~f0" | find ";;;" | find /v "find" && exit /b 0
; if "%~2" equ "" type "%~f0" | find ";;;" | find /v "find" && exit /b 0
; setlocal enableDelayedExpansion
; if "%~1" equ "/l" (
;  set "_files=%~2"
;  echo !_files:;=%NL%!>"%TEMP%\file.paths"
;  set _process_file="%TEMP%\file.paths"
;  goto :get_info
; )

; if "%~1" equ "/f" if exist "%~2" (
;  set _process_file="%~2"
;  goto :get_info
; )

; echo incorect parameters & exit /b 1
; :get_info
; set "file_info="

; makecab /d InfFileName=%TEMP%\file.inf /d "DiskDirectory1=%TEMP%" /f "%~f0"  /f %_process_file% /v0>nul

; for /f "usebackq skip=4 delims=" %%f in ("%TEMP%\file.inf") do (
;  set "file_info=%%f"
;  echo !file_info:,=%nl%!
; )

; endlocal
;endlocal
; del /q /f %TEMP%\file.inf 2>nul
; del /q /f %TEMP%\file.path 2>nul
; exit /b 0

.set DoNotCopyFiles=on
.set DestinationDir=;
.set RptFileName=nul
.set InfFooter=;
.set InfHeader=;
.Set ChecksumWidth=8
.Set InfDiskLineFormat=;
.Set Cabinet=off
.Set Compress=off
.Set GenerateInf=ON
.Set InfDiskHeader=;
.Set InfFileHeader=;
.set InfCabinetHeader=;
.Set InfFileLineFormat=",file:*file*,date:*date*,size:*size*,csum:*csum*,time:*time*,vern:*ver*,vers:*vers*,lang:*lang*"

example output (it has a string version which is a small addition to wmic method :) ):

c:> fileinfo.bat /l C:\install.exe
    file:install.exe
    date:11/07/07
    size:562688
    csum:380ef239
    time:07:03:18a
    vern:9.0.21022.8
    vers:9.0.21022.8 built by: RTM
    lang:1033

and one more Using shell.application and hybrid batch\jscript.Here's tooptipInfo.bat :

@if (@X)==(@Y) @end /* JScript comment
    @echo off

    rem :: the first argument is the script name as it will be used for proper help message
    cscript //E:JScript //nologo "%~f0" %*

    exit /b %errorlevel%

@if (@X)==(@Y) @end JScript comment */

////// 
FSOObj = new ActiveXObject("Scripting.FileSystemObject");
var ARGS = WScript.Arguments;
if (ARGS.Length < 1 ) {
 WScript.Echo("No file passed");
 WScript.Quit(1);
}
var filename=ARGS.Item(0);
var objShell=new ActiveXObject("Shell.Application");
/////


//fso
ExistsItem = function (path) {
    return FSOObj.FolderExists(path)||FSOObj.FileExists(path);
}

getFullPath = function (path) {
    return FSOObj.GetAbsolutePathName(path);
}
//

//paths
getParent = function(path){
    var splitted=path.split("\\");
    var result="";
    for (var s=0;s<splitted.length-1;s++){
        if (s==0) {
            result=splitted[s];
        } else {
            result=result+"\\"+splitted[s];
        }
    }
    return result;
}


getName = function(path){
    var splitted=path.split("\\");
    return splitted[splitted.length-1];
}
//

function main(){
    if (!ExistsItem(filename)) {
        WScript.Echo(filename + " does not exist");
        WScript.Quit(2);
    }
    var fullFilename=getFullPath(filename);
    var namespace=getParent(fullFilename);
    var name=getName(fullFilename);
    var objFolder=objShell.NameSpace(namespace);
    var objItem=objFolder.ParseName(name);
    //https://msdn.microsoft.com/en-us/library/windows/desktop/bb787870(v=vs.85).aspx
    WScript.Echo(fullFilename + " : ");
    WScript.Echo(objFolder.GetDetailsOf(objItem,-1));

}

main();

used against cmd.exe :

C:\Windows\System32\cmd.exe :
File description: Windows Command Processor
Company: Microsoft Corporation
File version: 6.3.9600.16384
Date created: ?22-?Aug-?13 ??13:03
Size: 347 KB

Generating PDF files with JavaScript

I've just written a library called jsPDF which generates PDFs using Javascript alone. It's still very young, and I'll be adding features and bug fixes soon. Also got a few ideas for workarounds in browsers that do not support Data URIs. It's licensed under a liberal MIT license.

I came across this question before I started writing it and thought I'd come back and let you know :)

Generate PDFs in Javascript

Example create a "Hello World" PDF file.

_x000D_
_x000D_
// Default export is a4 paper, portrait, using milimeters for units_x000D_
var doc = new jsPDF()_x000D_
_x000D_
doc.text('Hello world!', 10, 10)_x000D_
doc.save('a4.pdf')
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf/1.3.5/jspdf.debug.js"></script>
_x000D_
_x000D_
_x000D_

C++ class forward declaration

class tile_tree_apple should be defined in a separate .h file.

tta.h:
#include "tile.h"

class tile_tree_apple : public tile
{
      public:
          tile onDestroy() {return *new tile_grass;};
          tile tick() {if (rand()%20==0) return *new tile_tree;};
          void onCreate() {health=rand()%5+4; type=TILET_TREE_APPLE;}; 
          tile onUse() {return *new tile_tree;};       
};

file tt.h
#include "tile.h"

class tile_tree : public tile
{
      public:
          tile onDestroy() {return *new tile_grass;};
          tile tick() {if (rand()%20==0) return *new tile_tree_apple;};
          void onCreate() {health=rand()%5+4; type=TILET_TREE;};        
};

another thing: returning a tile and not a tile reference is not a good idea, unless a tile is a primitive or very "small" type.

Beautiful Soup and extracting a div and its contents by ID

soup.find("tagName",attrs={ "id" : "articlebody" })

End of File (EOF) in C

EOF is -1 because that's how it's defined. The name is provided by the standard library headers that you #include. They make it equal to -1 because it has to be something that can't be mistaken for an actual byte read by getchar(). getchar() reports the values of actual bytes using positive number (0 up to 255 inclusive), so -1 works fine for this.

The != operator means "not equal". 0 stands for false, and anything else stands for true. So what happens is, we call the getchar() function, and compare the result to -1 (EOF). If the result was not equal to EOF, then the result is true, because things that are not equal are not equal. If the result was equal to EOF, then the result is false, because things that are equal are not (not equal).

The call to getchar() returns EOF when you reach the "end of file". As far as C is concerned, the 'standard input' (the data you are giving to your program by typing in the command window) is just like a file. Of course, you can always type more, so you need an explicit way to say "I'm done". On Windows systems, this is control-Z. On Unix systems, this is control-D.

The example in the book is not "wrong". It depends on what you actually want to do. Reading until EOF means that you read everything, until the user says "I'm done", and then you can't read any more. Reading until '\n' means that you read a line of input. Reading until '\0' is a bad idea if you expect the user to type the input, because it is either hard or impossible to produce this byte with a keyboard at the command prompt :)

How to force a view refresh without having it trigger automatically from an observable?

In some circumstances it might be useful to simply remove the bindings and then re-apply:

ko.cleanNode(document.getElementById(element_id))
ko.applyBindings(viewModel, document.getElementById(element_id))

Merge Cell values with PHPExcel - PHP

$this->excel->setActiveSheetIndex(0)->mergeCells("A".($p).":B".($p)); for dynamic merging of cells

What's the difference between HTML 'hidden' and 'aria-hidden' attributes?

Semantic Difference

According to HTML 5.2:

When specified on an element, [the hidden attribute] indicates that the element is not yet, or is no longer, directly relevant to the page’s current state, or that it is being used to declare content to be reused by other parts of the page as opposed to being directly accessed by the user.

Examples include a tab list where some panels are not exposed, or a log-in screen that goes away after a user logs in. I like to call these things “temporally relevant” i.e. they are relevant based on timing.

On the other hand, ARIA 1.1 says:

[The aria-hidden state] indicates whether an element is exposed to the accessibility API.

In other words, elements with aria-hidden="true" are removed from the accessibility tree, which most assistive technology honors, and elements with aria-hidden="false" will definitely be exposed to the tree. Elements without the aria-hidden attribute are in the "undefined (default)" state, which means user agents should expose it to the tree based on its rendering. E.g. a user agent may decide to remove it if its text color matches its background color.

Now let’s compare semantics. It’s appropriate to use hidden, but not aria-hidden, for an element that is not yet “temporally relevant”, but that might become relevant in the future (in which case you would use dynamic scripts to remove the hidden attribute). Conversely, it’s appropriate to use aria-hidden, but not hidden, on an element that is always relevant, but with which you don’t want to clutter the accessibility API; such elements might include “visual flair”, like icons and/or imagery that are not essential for the user to consume.

Effective Difference

The semantics have predictable effects in browsers/user agents. The reason I make a distinction is that user agent behavior is recommended, but not required by the specifications.

The hidden attribute should hide an element from all presentations, including printers and screen readers (assuming these devices honor the HTML specs). If you want to remove an element from the accessibility tree as well as visual media, hidden would do the trick. However, do not use hidden just because you want this effect. Ask yourself if hidden is semantically correct first (see above). If hidden is not semantically correct, but you still want to visually hide the element, you can use other techniques such as CSS.

Elements with aria-hidden="true" are not exposed to the accessibility tree, so for example, screen readers won’t announce them. This technique should be used carefully, as it will provide different experiences to different users: accessible user agents won’t announce/render them, but they are still rendered on visual agents. This can be a good thing when done correctly, but it has the potential to be abused.

Syntactic Difference

Lastly, there is a difference in syntax between the two attributes.

hidden is a boolean attribute, meaning if the attribute is present it is true—regardless of whatever value it might have—and if the attribute is absent it is false. For the true case, the best practice is to either use no value at all (<div hidden>...</div>), or the empty string value (<div hidden="">...</div>). I would not recommend hidden="true" because someone reading/updating your code might infer that hidden="false" would have the opposite effect, which is simply incorrect.

aria-hidden, by contrast, is an enumerated attribute, allowing one of a finite list of values. If the aria-hidden attribute is present, its value must be either "true" or "false". If you want the "undefined (default)" state, remove the attribute altogether.


Further reading: https://github.com/chharvey/chharvey.github.io/wiki/Hidden-Content

Sleep function in ORACLE

Create a procedure which just does your lock and install it into a different user, who is "trusted" with dbms_lock ( USERA ), grant USERA access to dbms_lock.

Then just grant USERB access to this function. They then wont need to be able to access DBMS_LOCK

( make sure you don't have usera and userb in your system before running this )

Connect as a user with grant privs for dbms_lock, and can create users

drop user usera cascade;
drop user userb cascade;
create user usera default tablespace users identified by abc123;
grant create session to usera;
grant resource to usera;
grant execute on dbms_lock to usera;

create user userb default tablespace users identified by abc123;
grant create session to userb;
grant resource to useb

connect usera/abc123;

create or replace function usera.f_sleep( in_time number ) return number is
begin
 dbms_lock.sleep(in_time);
 return 1;
end;
/

grant execute on usera.f_sleep to userb;

connect userb/abc123;

/* About to sleep as userb */
select usera.f_sleep(5) from dual;
/* Finished sleeping as userb */

/* Attempt to access dbms_lock as userb.. Should fail */

begin
  dbms_lock.sleep(5);
end;
/

/* Finished */

Update .NET web service to use TLS 1.2

Three steps needed:

  1. Explicitly mark SSL2.0, TLS1.0, TLS1.1 as forbidden on your server machine, by adding Enabled=0 and DisabledByDefault=1 to your registry (the full path is HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols). See screen for details registry

  2. Explicitly enable TLS1.2 by following the steps from 1. Just use Enabled=1 and DisabledByDefault=0 respectively.

NOTE: verify server version: Windows Server 2003 does not support the TLS 1.2 protocol

  1. Enable TLS1.2 only on app level, like @John Wu suggested above.

    System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

Hope this guide helps.

UPDATE As @Subbu mentioned: Official guide

How to pass macro definition from "make" command line arguments (-D) to C source code?

Because of low reputation, I cannot comment the accepted answer.

I would like to mention the predefined variable CPPFLAGS. It might represent a better fit than CFLAGS or CXXFLAGS, since it is described by the GNU Make manual as:

Extra flags to give to the C preprocessor and programs that use it (the C and Fortran compilers).

Examples of built-in implicit rules that use CPPFLAGS

  • n.o is made automatically from n.c with a recipe of the form:
    • $(CC) $(CPPFLAGS) $(CFLAGS) -c
  • n.o is made automatically from n.cc, n.cpp, or n.C with a recipe of the form:
    • $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c

One would use the command make CPPFLAGS=-Dvar=123 to define the desired macro.

More info

Oracle find a constraint

maybe this can help..

SELECT constraint_name, constraint_type, column_name
from user_constraints natural join user_cons_columns
where table_name = "my_table_name";

Python: Ignore 'Incorrect padding' error when base64 decoding

As said in other responses, there are various ways in which base64 data could be corrupted.

However, as Wikipedia says, removing the padding (the '=' characters at the end of base64 encoded data) is "lossless":

From a theoretical point of view, the padding character is not needed, since the number of missing bytes can be calculated from the number of Base64 digits.

So if this is really the only thing "wrong" with your base64 data, the padding can just be added back. I came up with this to be able to parse "data" URLs in WeasyPrint, some of which were base64 without padding:

import base64
import re

def decode_base64(data, altchars=b'+/'):
    """Decode base64, padding being optional.

    :param data: Base64 data as an ASCII byte string
    :returns: The decoded byte string.

    """
    data = re.sub(rb'[^a-zA-Z0-9%s]+' % altchars, b'', data)  # normalize
    missing_padding = len(data) % 4
    if missing_padding:
        data += b'='* (4 - missing_padding)
    return base64.b64decode(data, altchars)

Tests for this function: weasyprint/tests/test_css.py#L68

Abstract Class vs Interface in C++

I assume that with interface you mean a C++ class with only pure virtual methods (i.e. without any code), instead with abstract class you mean a C++ class with virtual methods that can be overridden, and some code, but at least one pure virtual method that makes the class not instantiable. e.g.:

class MyInterface
{
public:
  // Empty virtual destructor for proper cleanup
  virtual ~MyInterface() {}

  virtual void Method1() = 0;
  virtual void Method2() = 0;
};


class MyAbstractClass
{
public:
  virtual ~MyAbstractClass();

  virtual void Method1();
  virtual void Method2();
  void Method3();

  virtual void Method4() = 0; // make MyAbstractClass not instantiable
};

In Windows programming, interfaces are fundamental in COM. In fact, a COM component exports only interfaces (i.e. pointers to v-tables, i.e. pointers to set of function pointers). This helps defining an ABI (Application Binary Interface) that makes it possible to e.g. build a COM component in C++ and use it in Visual Basic, or build a COM component in C and use it in C++, or build a COM component with Visual C++ version X and use it with Visual C++ version Y. In other words, with interfaces you have high decoupling between client code and server code.

Moreover, when you want to build DLL's with a C++ object-oriented interface (instead of pure C DLL's), as described in this article, it's better to export interfaces (the "mature approach") instead of C++ classes (this is basically what COM does, but without the burden of COM infrastructure).

I'd use an interface if I want to define a set of rules using which a component can be programmed, without specifying a concrete particular behavior. Classes that implement this interface will provide some concrete behavior themselves.

Instead, I'd use an abstract class when I want to provide some default infrastructure code and behavior, and make it possible to client code to derive from this abstract class, overriding the pure virtual methods with some custom code, and complete this behavior with custom code. Think for example of an infrastructure for an OpenGL application. You can define an abstract class that initializes OpenGL, sets up the window environment, etc. and then you can derive from this class and implement custom code for e.g. the rendering process and handling user input:

// Abstract class for an OpenGL app.
// Creates rendering window, initializes OpenGL; 
// client code must derive from it 
// and implement rendering and user input.
class OpenGLApp
{
public:
  OpenGLApp();
  virtual ~OpenGLApp();
  ...

  // Run the app    
  void Run();


  // <---- This behavior must be implemented by the client ---->

  // Rendering
  virtual void Render() = 0;

  // Handle user input
  // (returns false to quit, true to continue looping)
  virtual bool HandleInput() = 0;

  // <--------------------------------------------------------->


private:
  //
  // Some infrastructure code
  //
  ... 
  void CreateRenderingWindow();
  void CreateOpenGLContext();
  void SwapBuffers();
};


class MyOpenGLDemo : public OpenGLApp
{
public:
  MyOpenGLDemo();
  virtual ~MyOpenGLDemo();

  // Rendering
  virtual void Render();  // implements rendering code

  // Handle user input
  virtual bool HandleInput(); // implements user input handling


  //  ... some other stuff
};

Pass form data to another page with php

The best way to accomplish that is to use POST which is a method of Hypertext Transfer Protocol https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods

index.php

<html>
<body>

<form action="site2.php" method="post">
Name: <input type="text" name="name">
Email: <input type="text" name="email">
<input type="submit">
</form>

</body>
</html> 

site2.php

 <html>
 <body>

 Hello <?php echo $_POST["name"]; ?>!<br>
 Your mail is <?php echo $_POST["mail"]; ?>.

 </body>
 </html> 

output

Hello "name" !

Your email is "[email protected]" .

python int( ) function

int() only works for strings that look like integers; it will fail for strings that look like floats. Use float() instead.

Actionbar notification count icon (badge) like Google has

Ok, for @AndrewS solution to work with v7 appCompat library:

<menu 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:someNamespace="http://schemas.android.com/apk/res-auto" >

    <item
        android:id="@+id/saved_badge"
        someNamespace:showAsAction="always"
        android:icon="@drawable/shape_notification" />

</menu>

.

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    super.onCreateOptionsMenu(menu, inflater);
    menu.clear();
    inflater.inflate(R.menu.main, menu);

    MenuItem item = menu.findItem(R.id.saved_badge);
    MenuItemCompat.setActionView(item, R.layout.feed_update_count);
    View view = MenuItemCompat.getActionView(item);
    notifCount = (Button)view.findViewById(R.id.notif_count);
    notifCount.setText(String.valueOf(mNotifCount));
}

private void setNotifCount(int count){
    mNotifCount = count;
    supportInvalidateOptionsMenu();
}

The rest of the code is the same.

Different ways of loading a file as an InputStream

After trying some ways to load the file with no success, I remembered I could use FileInputStream, which worked perfectly.

InputStream is = new FileInputStream("file.txt");

This is another way to read a file into an InputStream, it reads the file from the currently running folder.

Count number of occurrences by month

Use a pivot table. You can manually refresh a pivot table's data source by right-clicking on it and clicking refresh. Otherwise you can set up a worksheet_change macro - or just a refresh button. Pivot Table tutorial is here: http://chandoo.org/wp/2009/08/19/excel-pivot-tables-tutorial/

1) Create a Month column from your Date column (e.g. =TEXT(B2,"MMM") )

image1

2) Create a Year column from your Date column (e.g. =TEXT(B2,"YYYY") )

image2

3) Add a Count column, with "1" for each value

image3

4) Create a Pivot table with the fields, Count, Month and Year 5) Drag the Year and Month fields into Row Labels. Ensure that Year is above month so your Pivot table first groups by year, then by month 6) Drag the Count field into Values to create a Count of Count

image4

There are better tutorials I'm sure just google/bing "pivot table tutorial".

How to jQuery clone() and change id?

_x000D_
_x000D_
$('#cloneDiv').click(function(){_x000D_
_x000D_
_x000D_
  // get the last DIV which ID starts with ^= "klon"_x000D_
  var $div = $('div[id^="klon"]:last');_x000D_
_x000D_
  // Read the Number from that DIV's ID (i.e: 3 from "klon3")_x000D_
  // And increment that number by 1_x000D_
  var num = parseInt( $div.prop("id").match(/\d+/g), 10 ) +1;_x000D_
_x000D_
  // Clone it and assign the new ID (i.e: from num 4 to ID "klon4")_x000D_
  var $klon = $div.clone().prop('id', 'klon'+num );_x000D_
_x000D_
  // Finally insert $klon wherever you want_x000D_
  $div.after( $klon.text('klon'+num) );_x000D_
_x000D_
});
_x000D_
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>_x000D_
_x000D_
<button id="cloneDiv">CLICK TO CLONE</button> _x000D_
_x000D_
<div id="klon1">klon1</div>_x000D_
<div id="klon2">klon2</div>
_x000D_
_x000D_
_x000D_


Scrambled elements, retrieve highest ID

Say you have many elements with IDs like klon--5 but scrambled (not in order). Here we cannot go for :last or :first, therefore we need a mechanism to retrieve the highest ID:

_x000D_
_x000D_
const $all = $('[id^="klon--"]');_x000D_
const maxID = Math.max.apply(Math, $all.map((i, el) => +el.id.match(/\d+$/g)[0]).get());_x000D_
const nextId = maxID + 1;_x000D_
_x000D_
console.log(`New ID is: ${nextId}`);
_x000D_
<div id="klon--12">12</div>_x000D_
<div id="klon--34">34</div>_x000D_
<div id="klon--8">8</div>_x000D_
_x000D_
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
_x000D_
_x000D_
_x000D_

Connecting to TCP Socket from browser using javascript

This will be possible via the navigator interface as shown below:

navigator.tcpPermission.requestPermission({remoteAddress:"127.0.0.1", remotePort:6789}).then(
  () => {
    // Permission was granted
    // Create a new TCP client socket and connect to remote host
    var mySocket = new TCPSocket("127.0.0.1", 6789);

    // Send data to server
    mySocket.writeable.write("Hello World").then(
        () => {

            // Data sent sucessfully, wait for response
            console.log("Data has been sent to server");
            mySocket.readable.getReader().read().then(
                ({ value, done }) => {
                    if (!done) {
                        // Response received, log it:
                        console.log("Data received from server:" + value);
                    }

                    // Close the TCP connection
                    mySocket.close();
                }
            );
        },
        e => console.error("Sending error: ", e)
    );
  }
);

More details are outlined in the w3.org tcp-udp-sockets documentation.

http://raw-sockets.sysapps.org/#interface-tcpsocket

https://www.w3.org/TR/tcp-udp-sockets/

Another alternative is to use Chrome Sockets

Creating connections

chrome.sockets.tcp.create({}, function(createInfo) {
  chrome.sockets.tcp.connect(createInfo.socketId,
    IP, PORT, onConnectedCallback);
});

Sending data

chrome.sockets.tcp.send(socketId, arrayBuffer, onSentCallback);

Receiving data

chrome.sockets.tcp.onReceive.addListener(function(info) {
  if (info.socketId != socketId)
    return;
  // info.data is an arrayBuffer.
});

You can use also attempt to use HTML5 Web Sockets (Although this is not direct TCP communication):

var connection = new WebSocket('ws://IPAddress:Port');

connection.onopen = function () {
  connection.send('Ping'); // Send the message 'Ping' to the server
};

http://www.html5rocks.com/en/tutorials/websockets/basics/

Your server must also be listening with a WebSocket server such as pywebsocket, alternatively you can write your own as outlined at Mozilla

How to hide column of DataGridView when using custom DataSource?

I"m not sure if its too late, but the problem is that, you cannot set the columns in design mode if you are binding at runtime. So if you are binding at runtime, go ahead and remove the columns from the design mode and do it pragmatically

ex..

     if (dt.Rows.Count > 0)
    {
        dataGridViewProjects.DataSource = dt;
        dataGridViewProjects.Columns["Title"].Width = 300;
        dataGridViewProjects.Columns["ID"].Visible = false;
    }

Disabling the button after once click

think simple

<button id="button1" onclick="Click();">ok</button>
<script>
    var buttonClick = false;
    function Click() {
        if (buttonClick) {
            return;
        }
        else {
            buttonClick = true;
            //todo
            alert("ok");
            //buttonClick = false;
        }
    }
</script>

if you want run once :)

Java equivalent of unsigned long long?

For unsigned long you can use UnsignedLong class from Guava library:

It supports various operations:

  • plus
  • minus
  • times
  • mod
  • dividedBy

The thing that seems missing at the moment are byte shift operators. If you need those you can use BigInteger from Java.

Plotting time in Python with Matplotlib

7 years later and this code has helped me. However, my times still were not showing up correctly.

enter image description here

Using Matplotlib 2.0.0 and I had to add the following bit of code from Editing the date formatting of x-axis tick labels in matplotlib by Paul H.

import matplotlib.dates as mdates
myFmt = mdates.DateFormatter('%d')
ax.xaxis.set_major_formatter(myFmt)

I changed the format to (%H:%M) and the time displayed correctly. enter image description here

All thanks to the community.

How to use DbContext.Database.SqlQuery<TElement>(sql, params) with stored procedure? EF Code First CTP5

Also, you can use the "sql" parameter as a format specifier:

context.Database.SqlQuery<MyEntityType>("mySpName @param1 = {0}", param1)

(HTML) Download a PDF file instead of opening them in browser when clicked

you can add the following code

_x000D_
_x000D_
<a href='http://v2.immo-facile.com/catalog/admin-v2/product_info.pdf' class='btnPdf' title='pdf'  target='_blank' type='application/pdf' >Télécharger la fiche du bien</a>
_x000D_
_x000D_
_x000D_

Best practices for SQL varchar column length

No DBMS I know of has any "optimization" that will make a VARCHAR with a 2^n length perform better than one with a max length that is not a power of 2.

I think early SQL Server versions actually treated a VARCHAR with length 255 differently than one with a higher maximum length. I don't know if this is still the case.

For almost all DBMS, the actual storage that is required is only determined by the number of characters you put into it, not the max length you define. So from a storage point of view (and most probably a performance one as well), it does not make any difference whether you declare a column as VARCHAR(100) or VARCHAR(500).

You should see the max length provided for a VARCHAR column as a kind of constraint (or business rule) rather than a technical/physical thing.

For PostgreSQL the best setup is to use text without a length restriction and a CHECK CONSTRAINT that limits the number of characters to whatever your business requires.

If that requirement changes, altering the check constraint is much faster than altering the table (because the table does not need to be re-written)

The same can be applied for Oracle and others - in Oracle it would be VARCHAR(4000) instead of text though.

I don't know if there is a physical storage difference between VARCHAR(max) and e.g. VARCHAR(500) in SQL Server. But apparently there is a performance impact when using varchar(max) as compared to varchar(8000).

See this link (posted by Erwin Brandstetter as a comment)

Edit 2013-09-22

Regarding bigown's comment:

In Postgres versions before 9.2 (which was not available when I wrote the initial answer) a change to the column definition did rewrite the whole table, see e.g. here. Since 9.2 this is no longer the case and a quick test confirmed that increasing the column size for a table with 1.2 million rows indeed only took 0.5 seconds.

For Oracle this seems to be true as well, judging by the time it takes to alter a big table's varchar column. But I could not find any reference for that.

For MySQL the manual says "In most cases, ALTER TABLE makes a temporary copy of the original table". And my own tests confirm that: running an ALTER TABLE on a table with 1.2 million rows (the same as in my test with Postgres) to increase the size of a column took 1.5 minutes. In MySQL however you can not use the "workaround" to use a check constraint to limit the number of characters in a column.

For SQL Server I could not find a clear statement on this but the execution time to increase the size of a varchar column (again the 1.2 million rows table from above) indicates that no rewrite takes place.

Edit 2017-01-24

Seems I was (at least partially) wrong about SQL Server. See this answer from Aaron Bertrand that shows that the declared length of a nvarchar or varchar columns makes a huge difference for the performance.

JBoss default password

I just had to uncomment the line in jboss-eap-5.0\jboss-as\server\default\conf\props\jmx-console-users.properties

admin=admin

Thats it. Restart Jboss and I was about to get in to JBOSS JMX. Magically this even fixed the error that I used to get while shutting down Jboss from Eclipse.

How to convert an int to a hex string?

Let me add this one, because sometimes you just want the single digit representation

( x can be lower, 'x', or uppercase, 'X', the choice determines if the output letters are upper or lower.):

'{:x}'.format(15)
> f

And now with the new f'' format strings you can do:

f'{15:x}'
> f

To add 0 padding you can use 0>n:

f'{2034:0>4X}'
> 07F2

NOTE: the initial 'f' in f'{15:x}' is to signify a format string

How to get correlation of two vectors in python

The docs indicate that numpy.correlate is not what you are looking for:

numpy.correlate(a, v, mode='valid', old_behavior=False)[source]
  Cross-correlation of two 1-dimensional sequences.
  This function computes the correlation as generally defined in signal processing texts:
     z[k] = sum_n a[n] * conj(v[n+k])
  with a and v sequences being zero-padded where necessary and conj being the conjugate.

Instead, as the other comments suggested, you are looking for a Pearson correlation coefficient. To do this with scipy try:

from scipy.stats.stats import pearsonr   
a = [1,4,6]
b = [1,2,3]   
print pearsonr(a,b)

This gives

(0.99339926779878274, 0.073186395040328034)

You can also use numpy.corrcoef:

import numpy
print numpy.corrcoef(a,b)

This gives:

[[ 1.          0.99339927]
 [ 0.99339927  1.        ]]

Set UIButton title UILabel font size programmatically

I hope it will be help to you

[_button.titleLabel setFont:[UIFont systemFontOfSize:15]];  

good luck

How to get terminal's Character Encoding

The terminal uses environment variables to determine which character set to use, therefore you can determine it by looking at those variables:

echo $LC_CTYPE

or

echo $LANG

Rename file with Git

You've got "Bad Status" its because the target file cannot find or not present, like for example you call README file which is not in the current directory.

How to sort List<Integer>?

Ascending order:

 Collections.sort(lList); 

Descending order:

Collections.sort(lList, Collections.reverseOrder()); 

How to change the icon of an Android app in Eclipse?

Go into your AndroidManifest.xml file

  • Click on the Application Tab
  • Find the Text Box Labelled "Icon"
  • Then click the "Browse" button at the end of the text box
  • Click the Button Labelled: "Create New Icon..."

  • Create your icon
  • Click Finish
  • Click "Yes to All" if you already have the icon set to something else.

Enjoy using a gui rather then messing with an image editor! Hope this helps!

Regular expression for first and last name

Try these solutions, for maximum compatibility, as I have already posted here:

JavaScript:

var nm_re = /^(?:((([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-.\s])){1,}(['’,\-\.]){0,1}){2,}(([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-. ]))*(([ ]+){0,1}(((([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){1,})(['’\-,\.]){0,1}){2,}((([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){2,})?)*)$/;

HTML5:

<input type="text" name="full_name" id="full_name" pattern="^(?:((([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-.\s])){1,}(['’,\-\.]){0,1}){2,}(([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-. ]))*(([ ]+){0,1}(((([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){1,})(['’\-,\.]){0,1}){2,}((([^0-9_!¡?÷?¿/\\+=@#$%ˆ&*(){}|~<>;:[\]'’,\-\.\s])){2,})?)*)$" required>

Excel VBA function to print an array to the workbook

Create a variant array (easiest by reading equivalent range in to a variant variable).

Then fill the array, and assign the array directly to the range.

Dim myArray As Variant

myArray = Range("blahblah")

Range("bingbing") = myArray

The variant array will end up as a 2-D matrix.

Make Bootstrap's Carousel both center AND responsive?

in bootstrap v4, i center and fill the carousel img to the screen using

<img class="d-block mx-auto" max-width="100%" max-height="100%">

pretty sure this requires parent elements' height or width to be set

html,body{height:100%;}
.carousel,.carousel-item,.active{height:100%;}
.carousel-inner{height:100%;}

Send attachments with PHP Mail()?

For PHP 5.5.27 security update

$file = $path.$filename;
$content = file_get_contents( $file);
$content = chunk_split(base64_encode($content));
$uid = md5(uniqid(time()));
$name = basename($file);

// header
$header = "From: ".$from_name." <".$from_mail.">\r\n";
$header .= "Reply-To: ".$replyto."\r\n";
$header .= "MIME-Version: 1.0\r\n";
$header .= "Content-Type: multipart/mixed; boundary=\"".$uid."\"\r\n\r\n";

// message & attachment
$nmessage = "--".$uid."\r\n";
$nmessage .= "Content-type:text/plain; charset=iso-8859-1\r\n";
$nmessage .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
$nmessage .= $message."\r\n\r\n";
$nmessage .= "--".$uid."\r\n";
$nmessage .= "Content-Type: application/octet-stream; name=\"".$filename."\"\r\n";
$nmessage .= "Content-Transfer-Encoding: base64\r\n";
$nmessage .= "Content-Disposition: attachment; filename=\"".$filename."\"\r\n\r\n";
$nmessage .= $content."\r\n\r\n";
$nmessage .= "--".$uid."--";

if (mail($mailto, $subject, $nmessage, $header)) {
    return true; // Or do something here
} else {
  return false;
}

Integer to hex string in C++

For those of you who figured out that many/most of the ios::fmtflags don't work with std::stringstream yet like the template idea that Kornel posted way back when, the following works and is relatively clean:

#include <iomanip>
#include <sstream>


template< typename T >
std::string hexify(T i)
{
    std::stringbuf buf;
    std::ostream os(&buf);


    os << "0x" << std::setfill('0') << std::setw(sizeof(T) * 2)
       << std::hex << i;

    return buf.str().c_str();
}


int someNumber = 314159265;
std::string hexified = hexify< int >(someNumber);

Is it possible to save HTML page as PDF using JavaScript or jquery?

Yes. For example you can use the solution by https://grabz.it.

It's got a Javascript API which can be used in different ways to grab and manipulate the screenshot. In order to use it in your app you will need to first get an app key and secret and download the free Javascript SDK.

So, let's see a simple example for using it:

//first include the grabzit.min.js library in the web page
<script src="grabzit.min.js"></script>
//include the code below to add the screenshot to the body tag    
<script>
//use secret key to sign in. replace the url.
GrabzIt("Sign in to view your Application Key").ConvertURL("http://www.google.com").Create();
</script>

Then simply wait a short while and the image will automatically appear at the bottom of the page, without you needing to reload the page.

That's the simplest one. For more examples with image manipulation, attaching screenshots to elements and etc check the documentation.

Access images inside public folder in laravel

when you want to access images which are in public/images folder and if you want to access it without using laravel functions, use as follows:

<img src={{url('/images/photo.type')}} width="" height="" alt=""/>

This works fine.

TypeError: $.ajax(...) is not a function?

This is too late for an answer but this response may be helpful for future readers.

I would like to share a scenario where, say there are multiple html files(one base html and multiple sub-HTMLs) and $.ajax is being used in one of the sub-HTMLs.

Suppose in the sub-HTML, js is included via URL "https://code.jquery.com/jquery-3.5.0.js" and in the base/parent HTML, via URL -"https://code.jquery.com/jquery-3.1.1.slim.min.js", then the slim version of JS will be used across all pages which use this sub-HTML as well as the base HTML mentioned above.

This is especially true in case of using bootstrap framework which loads js using "https://code.jquery.com/jquery-3.1.1.slim.min.js".

So to resolve the problem, need to ensure that in all pages, js is included via URL "https://code.jquery.com/jquery-3.5.0.js" or whatever is the latest URL containing all JQuery libraries.

Thanks to Lily H. for pointing me towards this answer.

How can I make my flexbox layout take 100% vertical space?

Let me show you another way that works 100%. I will also add some padding for the example.

<div class = "container">
  <div class = "flex-pad-x">
    <div class = "flex-pad-y">
      <div class = "flex-pad-y">
        <div class = "flex-grow-y">
         Content Centered
        </div>
      </div>
    </div>
  </div>
</div>

.container {
  position: fixed;
  top: 0px;
  left: 0px;
  bottom: 0px;
  right: 0px;
  width: 100%;
  height: 100%;
}

  .flex-pad-x {
    padding: 0px 20px;
    height: 100%;
    display: flex;
  }

  .flex-pad-y {
    padding: 20px 0px;
    width: 100%;
    display: flex;
    flex-direction: column;
  }

  .flex-grow-y {
    flex-grow: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
   }

As you can see we can achieve this with a few wrappers for control while utilising the flex-grow & flex-direction attribute.

1: When the parent "flex-direction" is a "row", its child "flex-grow" works horizontally. 2: When the parent "flex-direction" is "columns", its child "flex-grow" works vertically.

Hope this helps

Daniel

How can I make a "color map" plot in matlab?

gevang's answer is great. There's another way as well to do this directly by using pcolor. Code:

[X,Y] = meshgrid(-8:.5:8);
R = sqrt(X.^2 + Y.^2) + eps;
Z = sin(R)./R;
figure;
subplot(1,3,1);
pcolor(X,Y,Z); 
subplot(1,3,2);
pcolor(X,Y,Z); shading flat;
subplot(1,3,3);
pcolor(X,Y,Z); shading interp;

Output:

enter image description here

Also, pcolor is flat too, as show here (pcolor is the 2d base; the 3d figure above it is generated using mesh):

enter image description here

How to write text on a image in windows using python opencv2

This is indeed a bit of an annoying problem. For python 2.x.x you use:

cv2.CV_FONT_HERSHEY_SIMPLEX

and for Python 3.x.x:

cv2.FONT_HERSHEY_SIMPLEX

I recommend using a autocomplete environment(pyscripter or scipy for example). If you lookup example code, make sure they use the same version of Python(if they don't make sure you change the code).

Difference between @click and v-on:click Vuejs

v-bind and v-on are two frequently used directives in vuejs html template. So they provided a shorthand notation for the both of them as follows:

You can replace v-on: with @

v-on:click='someFunction'

as:

@click='someFunction'

Another example:

v-on:keyup='someKeyUpFunction'

as:

@keyup='someKeyUpFunction'

Similarly, v-bind with :

v-bind:href='var1'

Can be written as:

:href='var1'

Hope it helps!

Why does Git treat this text file as a binary file?

I have had same problem. I found the thread when I search solution on google, still I don't find any clue. But I think I found the reason after studying, the below example will explain clearly my clue.

    echo "new text" > new.txt
    git add new.txt
    git commit -m "dummy"

for now, the file new.txt is considered as a text file.

    echo -e "newer text\000" > new.txt
    git diff

you will get this result

diff --git a/new.txt b/new.txt
index fa49b07..410428c 100644
Binary files a/new.txt and b/new.txt differ

and try this

git diff -a

you will get below

    diff --git a/new.txt b/new.txt
    index fa49b07..9664e3f 100644
    --- a/new.txt
    +++ b/new.txt
    @@ -1 +1 @@
    -new file
    +newer text^@

How to add element to C++ array?

Use a vector:

#include <vector>

void foo() {
    std::vector <int> v;
    v.push_back( 1 );       // equivalent to v[0] = 1
}

What does "#include <iostream>" do?

In order to read or write to the standard input/output streams you need to include it.

int main( int argc, char * argv[] )
{
    std::cout << "Hello World!" << std::endl;
    return 0;
}

That program will not compile unless you add #include <iostream>

The second line isn't necessary

using namespace std;

What that does is tell the compiler that symbol names defined in the std namespace are to be brought into your program's scope, so you can omit the namespace qualifier, and write for example

#include <iostream>
using namespace std;
int main( int argc, char * argv[] )
{
    cout << "Hello World!" << endl;
    return 0;
}

Notice you no longer need to refer to the output stream with the fully qualified name std::cout and can use the shorter name cout.

I personally don't like bringing in all symbols in the namespace of a header file... I'll individually select the symbols I want to be shorter... so I would do this:

#include <iostream>
using std::cout;
using std::endl;

int main( int argc, char * argv[] )
{
    cout << "Hello World!" << endl;
    return 0;
}

But that is a matter of personal preference.

Spring Boot - Cannot determine embedded database driver class for database type NONE

I tried all the mentioned things above but could not resolve the issue. I am using SQLite and my SQLite file was in the resources directory.

a) Set Up done for IDE

I need to manually add below lines in the .classpath file of my project.

<classpathentry kind="src" path="resources"/>
<classpathentry kind="output" path="target/classes"/>

After that, I refreshed and Cleaned the project from MenuBar at the top. like Project->Clean->My Project Name.

After that, I run the project and problem resolved.

application.properties for my project is

spring.datasource.url=jdbc:sqlite:resources/apiusers.sqlite
spring.datasource.driver-class-name=org.sqlite.JDBC
spring.jpa.properties.hibernate.dialect=com.enigmabridge.hibernate.dialect.SQLiteDialect
spring.datasource.username=
spring.datasource.password=
spring.jpa.hibernate.ddl-auto=update

b) Set Up done if Jar deployment throw same error

You need to add following lines to your pom.xml

  <build>
        <resources>
        <resource>
            <directory>resources</directory>
            <targetPath>${project.build.outputDirectory}</targetPath>
            <includes>
                <include>application.properties</include>
            </includes>
        </resource>
    </resources>
</build>

May be it may help someone.

mySQL select IN range

You can't, but you can use BETWEEN

SELECT job FROM mytable WHERE id BETWEEN 10 AND 15

Note that BETWEEN is inclusive, and will include items with both id 10 and 15.

If you do not want inclusion, you'll have to fall back to using the > and < operators.

SELECT job FROM mytable WHERE id > 10 AND id < 15

Specifying a custom DateTime format when serializing with Json.Net

There is another solution I've been using. Just create a string property and use it for json. This property wil return date properly formatted.

class JSonModel {
    ...

    [JsonIgnore]
    public DateTime MyDate { get; set; }

    [JsonProperty("date")]
    public string CustomDate {
        get { return MyDate.ToString("ddMMyyyy"); }
        // set { MyDate = DateTime.Parse(value); }
        set { MyDate = DateTime.ParseExact(value, "ddMMyyyy", null); }
    }

    ...
}

This way you don't have to create extra classes. Also, it allows you to create diferent data formats. e.g, you can easily create another Property for Hour using the same DateTime.

Delete last char of string

As an alternate to adding a comma for each item you could just using String.Join:

var strgroupids = String.Join(",",  groupIds);

This will add the seperator ("," in this instance) between each element in the array.

Reflection: How to Invoke Method with parameters

I would use it like this, its way shorter and it won't give any problems

        dynamic result = null;
        if (methodInfo != null)
        {
            ParameterInfo[] parameters = methodInfo.GetParameters();
            object classInstance = Activator.CreateInstance(type, null);
            result = methodInfo.Invoke(classInstance, parameters.Length == 0 ? null : parametersArray);
        }

How to stop INFO messages displaying on spark console?

Simply add below param to your spark-shell OR spark-submit command

--conf "spark.driver.extraJavaOptions=-Dlog4jspark.root.logger=WARN,console"

Check exact property name (log4jspark.root.logger here) from log4j.properties file. Hope this helps, cheers!

What is the 'instanceof' operator used for in Java?

class Test48{
public static void main (String args[]){
Object Obj=new Hello();
//Hello obj=new Hello;
System.out.println(Obj instanceof String);
System.out.println(Obj instanceof Hello);
System.out.println(Obj instanceof Object);
Hello h=null;
System.out.println(h instanceof Hello);
System.out.println(h instanceof Object);
}
}  

How can I debug a Perl script?

The most effective debugging tool is still careful thought, coupled with judiciously placed print statements.

Brian Kernighan, "Unix for Beginners" (1979)

(And enhancing print statements with Data::Dumper)

WPF Add a Border to a TextBlock

No, you need to wrap your TextBlock in a Border. Example:

<Border BorderThickness="1" BorderBrush="Black">
    <TextBlock ... />
</Border>

Of course, you can set these properties (BorderThickness, BorderBrush) through styles as well:

<Style x:Key="notCalledBorder" TargetType="{x:Type Border}">
    <Setter Property="BorderThickness" Value="1" />
    <Setter Property="BorderBrush" Value="Black" />
</Style>

<Border Style="{StaticResource notCalledBorder}">
    <TextBlock ... />
</Border>

Running PowerShell as another user, and launching a script

Try adding the RunAs option to your Start-Process

Start-Process powershell.exe -Credential $Credential -Verb RunAs -ArgumentList ("-file $args")

CREATE FILE encountered operating system error 5(failed to retrieve text for this error. Reason: 15105)

copy your --.MDF,--.LDF files to pate this location For 2008 server C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA 2.

In sql server 2008 use ATTACH and select same location for add

How to get document height and width without using jquery

Even the last example given on http://www.howtocreate.co.uk/tutorials/javascript/browserwindow is not working on Quirks mode. Easier to find than I thought, this seems to be the solution(extracted from latest jquery code):

Math.max(
    document.documentElement["clientWidth"],
    document.body["scrollWidth"],
    document.documentElement["scrollWidth"],
    document.body["offsetWidth"],
    document.documentElement["offsetWidth"]
);

just replace Width for "Height" to get Height.

The cast to value type 'Int32' failed because the materialized value is null

I was also facing the same problem and solved through making column as nullable using "?" operator.

Sequnce = db.mstquestionbanks.Where(x => x.IsDeleted == false && x.OrignalFormID == OriginalFormIDint).Select(x=><b>(int?)x.Sequence</b>).Max().ToString();

Sometimes null is returned.

Running multiple commands with xargs

One thing I do is to add to .bashrc/.profile this function:

function each() {
    while read line; do
        for f in "$@"; do
            $f $line
        done
    done
}

then you can do things like

... | each command1 command2 "command3 has spaces"

which is less verbose than xargs or -exec. You could also modify the function to insert the value from the read at an arbitrary location in the commands to each, if you needed that behavior also.

Returning a pointer to a vector element in c++

You can use the data function of the vector:

Returns a pointer to the first element in the vector.

If don't want the pointer to the first element, but by index, then you can try, for example:

//the index to the element that you want to receive its pointer:
int i = n; //(n is whatever integer you want)

std::vector<myObject> vec;
myObject* ptr_to_first = vec.data();

//or

std::vector<myObject>* vec;
myObject* ptr_to_first = vec->data();

//then

myObject element = ptr_to_first[i]; //element at index i
myObject* ptr_to_element = &element;

Centering in CSS Grid

I know this question is a couple years old, but I am surprised to find that no one suggested:

   text-align: center;

this is a more universal property than justify-content, and is definitely not unique to grid, but I find that when dealing with text, which is what this question specifically asks about, that it aligns text to the center with-out affecting the space between grid items, or the vertical centering. It centers text horizontally where its stands on its vertical axis. I also find it to remove a layer of complexity that justify-content and align-items adds. justify-content and align-items affects the entire grid item or items, text-align centers the text without affecting the container it is in. Hope this helps.

Homebrew install specific version of formula?

I decided, against my better judgment, to create a formula for Maven 3.1.1, which homebrew/versions did not have. To do this:

  1. I forked homebrew/versions on github.
  2. I symlinked from $(brew --prefix)/Library/Taps to the local working copy of my fork. I'll call this my-homebrew/versions.
  3. I tested by specifying the formula as my-homebrew/versions/<formula>.
  4. I sent a pull request to homebrew/versions for my new formula.

Yay.

Error resolving template "index", template might not exist or might not be accessible by any of the configured Template Resolvers

this can be resolved by copying the below code in application.properties

spring.thymeleaf.enabled=false

How to change port number for apache in WAMP

In addition of the modification of the file C:\wamp64\bin\apache\apache2.4.27\conf\httpd.conf.
To get the url shortcuts working, edit the file C:\wamp64\wampmanager.conf and change the port:

[apache]
apachePortUsed = "8080"

Then exit and relaunch wamp.

Print array without brackets and commas

first

StringUtils.join(array, "");

second

Arrays.asList(arr).toString().substring(1).replaceFirst("]", "").replace(", ", "")

EDIT

probably the best one: Arrays.toString(arr)

How to update-alternatives to Python 3 without breaking apt?

As I didn't want to break anything, I did this to be able to use newer versions of Python3 than Python v3.4 :

$ sudo update-alternatives --install /usr/local/bin/python3 python3 /usr/bin/python3.6 1
update-alternatives: using /usr/bin/python3.6 to provide /usr/local/bin/python3 (python3) in auto mode
$ sudo update-alternatives --install /usr/local/bin/python3 python3 /usr/bin/python3.7 2
update-alternatives: using /usr/bin/python3.7 to provide /usr/local/bin/python3 (python3) in auto mode
$ update-alternatives --list python3
/usr/bin/python3.6
/usr/bin/python3.7
$ sudo update-alternatives --config python3
There are 2 choices for the alternative python3 (providing /usr/local/bin/python3).

  Selection    Path                Priority   Status
------------------------------------------------------------
* 0            /usr/bin/python3.7   2         auto mode
  1            /usr/bin/python3.6   1         manual mode
  2            /usr/bin/python3.7   2         manual mode

Press enter to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/bin/python3.6 to provide /usr/local/bin/python3 (python3) in manual mode
$ ls -l /usr/local/bin/python3 /etc/alternatives/python3 
lrwxrwxrwx 1 root root 18 2019-05-03 02:59:03 /etc/alternatives/python3 -> /usr/bin/python3.6*
lrwxrwxrwx 1 root root 25 2019-05-03 02:58:53 /usr/local/bin/python3 -> /etc/alternatives/python3*

The service cannot be started, either because it is disabled or because it has no enabled devices associated with it

This error can occur on anything that requires elevated privileges in Windows.

It happens when the "Application Information" service is disabled in Windows services. There are a few viruses that use this as an attack vector to prevent people from removing the virus. It also prevents people from installing software to remove viruses.

The normal way to fix this would be to run services.msc, or to go into Administrative Tools and run "Services". However, you will not be able to do that if the "Application Information" service is disabled.

Instead, reboot your computer into Safe Mode (reboot and press F8 until the Windows boot menu appears, select Safe Mode with Networking). Then run services.msc and look for services that are designated as "Disabled" in the Startup Type column. Change these "Disabled" services to "Automatic".

Make sure the "Application Information" service is set to a Startup Type of "Automatic".

When you are done enabling your services, click Ok at the bottom of the tool and reboot your computer back into normal mode. The problem should be resolved when Windows reboots.

Difference between Build Solution, Rebuild Solution, and Clean Solution in Visual Studio?

Taken from this link:

Build means compile and link only the source files that have changed since the last build, while Rebuild means compile and link all source files regardless of whether they changed or not. Build is the normal thing to do and is faster. Sometimes the versions of project target components can get out of sync and rebuild is necessary to make the build successful. In practice, you never need to Clean.

How do I check OS with a preprocessor directive?

There is no standard macro that is set according to C standard. Some C compilers will set one on some platforms (e.g. Apple's patched GCC sets a macro to indicate that it is compiling on an Apple system and for the Darwin platform). Your platform and/or your C compiler might set something as well, but there is no general way.

Like hayalci said, it's best to have these macros set in your build process somehow. It is easy to define a macro with most compilers without modifying the code. You can simply pass -D MACRO to GCC, i.e.

gcc -D Windows
gcc -D UNIX

And in your code:

#if defined(Windows)
// do some cool Windows stuff
#elif defined(UNIX)
// do some cool Unix stuff
#else
#    error Unsupported operating system
#endif

How to import functions from different js file in a Vue+webpack+vue-loader project

Say I want to import data into a component from src/mylib.js:

var test = {
  foo () { console.log('foo') },
  bar () { console.log('bar') },
  baz () { console.log('baz') }
}

export default test

In my .Vue file I simply imported test from src/mylib.js:

<script> 
  import test from '@/mylib'

  console.log(test.foo())
  ...
</script>

how to add values to an array of objects dynamically in javascript?

You have to instantiate the object first. The simplest way is:

var lab =["1","2","3"];
var val = [42,55,51,22];
var data = [];
for(var i=0; i<4; i++)  {
    data.push({label: lab[i], value: val[i]});
}

Or an other, less concise way, but closer to your original code:

for(var i=0; i<4; i++)  {
   data[i] = {};              // creates a new object
   data[i].label = lab[i];
   data[i].value = val[i];    
}

array() will not create a new array (unless you defined that function). Either Array() or new Array() or just [].

I recommend to read the MDN JavaScript Guide.

caching JavaScript files

I just finished my weekend project cached-webpgr.js which uses the localStorage / web storage to cache JavaScript files. This approach is very fast. My small test showed

  • Loading jQuery from CDN: Chrome 268ms, FireFox: 200ms
  • Loading jQuery from localStorage: Chrome 47ms, FireFox 14ms

The code to achieve that is tiny, you can check it out at my Github project https://github.com/webpgr/cached-webpgr.js

Here is a full example how to use it.

The complete library:

function _cacheScript(c,d,e){var a=new XMLHttpRequest;a.onreadystatechange=function(){4==a.readyState&&(200==a.status?localStorage.setItem(c,JSON.stringify({content:a.responseText,version:d})):console.warn("error loading "+e))};a.open("GET",e,!0);a.send()}function _loadScript(c,d,e,a){var b=document.createElement("script");b.readyState?b.onreadystatechange=function(){if("loaded"==b.readyState||"complete"==b.readyState)b.onreadystatechange=null,_cacheScript(d,e,c),a&&a()}:b.onload=function(){_cacheScript(d,e,c);a&&a()};b.setAttribute("src",c);document.getElementsByTagName("head")[0].appendChild(b)}function _injectScript(c,d,e,a){var b=document.createElement("script");b.type="text/javascript";c=JSON.parse(c);var f=document.createTextNode(c.content);b.appendChild(f);document.getElementsByTagName("head")[0].appendChild(b);c.version!=e&&localStorage.removeItem(d);a&&a()}function requireScript(c,d,e,a){var b=localStorage.getItem(c);null==b?_loadScript(e,c,d,a):_injectScript(b,c,d,a)};

Calling the library

requireScript('jquery', '1.11.2', 'http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js', function(){
    requireScript('examplejs', '0.0.3', 'example.js');
});

Using Jquery Datatable with AngularJs

visit this link for reference:http://codepen.io/kalaiselvan/pen/RRBzda

<script>  
var app=angular.module('formvalid', ['ui.bootstrap','ui.utils']);
app.controller('validationCtrl',function($scope){
  $scope.data=[
        [
            "Tiger Nixon",
            "System Architect",
            "Edinburgh",
            "5421",
            "2011\/04\/25",
            "$320,800"
        ],
        [
            "Garrett Winters",
            "Accountant",
            "Tokyo",
            "8422",
            "2011\/07\/25",
            "$170,750"
        ],
        [
            "Ashton Cox",
            "Junior Technical Author",
            "San Francisco",
            "1562",
            "2009\/01\/12",
            "$86,000"
        ],
        [
            "Cedric Kelly",
            "Senior Javascript Developer",
            "Edinburgh",
            "6224",
            "2012\/03\/29",
            "$433,060"
        ],
        [
            "Airi Satou",
            "Accountant",
            "Tokyo",
            "5407",
            "2008\/11\/28",
            "$162,700"
        ],
        [
            "Brielle Williamson",
            "Integration Specialist",
            "New York",
            "4804",
            "2012\/12\/02",
            "$372,000"
        ],
        [
            "Herrod Chandler",
            "Sales Assistant",
            "San Francisco",
            "9608",
            "2012\/08\/06",
            "$137,500"
        ],
        [
            "Rhona Davidson",
            "Integration Specialist",
            "Tokyo",
            "6200",
            "2010\/10\/14",
            "$327,900"
        ],
        [
            "Colleen Hurst",
            "Javascript Developer",
            "San Francisco",
            "2360",
            "2009\/09\/15",
            "$205,500"
        ],
        [
            "Sonya Frost",
            "Software Engineer",
            "Edinburgh",
            "1667",
            "2008\/12\/13",
            "$103,600"
        ],
        [
            "Jena Gaines",
            "Office Manager",
            "London",
            "3814",
            "2008\/12\/19",
            "$90,560"
        ],
        [
            "Quinn Flynn",
            "Support Lead",
            "Edinburgh",
            "9497",
            "2013\/03\/03",
            "$342,000"
        ],
        [
            "Charde Marshall",
            "Regional Director",
            "San Francisco",
            "6741",
            "2008\/10\/16",
            "$470,600"
        ],
        [
            "Haley Kennedy",
            "Senior Marketing Designer",
            "London",
            "3597",
            "2012\/12\/18",
            "$313,500"
        ],
        [
            "Tatyana Fitzpatrick",
            "Regional Director",
            "London",
            "1965",
            "2010\/03\/17",
            "$385,750"
        ],
        [
            "Michael Silva",
            "Marketing Designer",
            "London",
            "1581",
            "2012\/11\/27",
            "$198,500"
        ],
        [
            "Paul Byrd",
            "Chief Financial Officer (CFO)",
            "New York",
            "3059",
            "2010\/06\/09",
            "$725,000"
        ],
        [
            "Gloria Little",
            "Systems Administrator",
            "New York",
            "1721",
            "2009\/04\/10",
            "$237,500"
        ],
        [
            "Bradley Greer",
            "Software Engineer",
            "London",
            "2558",
            "2012\/10\/13",
            "$132,000"
        ],
        [
            "Dai Rios",
            "Personnel Lead",
            "Edinburgh",
            "2290",
            "2012\/09\/26",
            "$217,500"
        ],
        [
            "Jenette Caldwell",
            "Development Lead",
            "New York",
            "1937",
            "2011\/09\/03",
            "$345,000"
        ],
        [
            "Yuri Berry",
            "Chief Marketing Officer (CMO)",
            "New York",
            "6154",
            "2009\/06\/25",
            "$675,000"
        ],
        [
            "Caesar Vance",
            "Pre-Sales Support",
            "New York",
            "8330",
            "2011\/12\/12",
            "$106,450"
        ],
        [
            "Doris Wilder",
            "Sales Assistant",
            "Sidney",
            "3023",
            "2010\/09\/20",
            "$85,600"
        ],
        [
            "Angelica Ramos",
            "Chief Executive Officer (CEO)",
            "London",
            "5797",
            "2009\/10\/09",
            "$1,200,000"
        ],
        [
            "Gavin Joyce",
            "Developer",
            "Edinburgh",
            "8822",
            "2010\/12\/22",
            "$92,575"
        ],
        [
            "Jennifer Chang",
            "Regional Director",
            "Singapore",
            "9239",
            "2010\/11\/14",
            "$357,650"
        ],
        [
            "Brenden Wagner",
            "Software Engineer",
            "San Francisco",
            "1314",
            "2011\/06\/07",
            "$206,850"
        ],
        [
            "Fiona Green",
            "Chief Operating Officer (COO)",
            "San Francisco",
            "2947",
            "2010\/03\/11",
            "$850,000"
        ],
        [
            "Shou Itou",
            "Regional Marketing",
            "Tokyo",
            "8899",
            "2011\/08\/14",
            "$163,000"
        ],
        [
            "Michelle House",
            "Integration Specialist",
            "Sidney",
            "2769",
            "2011\/06\/02",
            "$95,400"
        ],
        [
            "Suki Burks",
            "Developer",
            "London",
            "6832",
            "2009\/10\/22",
            "$114,500"
        ],
        [
            "Prescott Bartlett",
            "Technical Author",
            "London",
            "3606",
            "2011\/05\/07",
            "$145,000"
        ],
        [
            "Gavin Cortez",
            "Team Leader",
            "San Francisco",
            "2860",
            "2008\/10\/26",
            "$235,500"
        ],
        [
            "Martena Mccray",
            "Post-Sales support",
            "Edinburgh",
            "8240",
            "2011\/03\/09",
            "$324,050"
        ],
        [
            "Unity Butler",
            "Marketing Designer",
            "San Francisco",
            "5384",
            "2009\/12\/09",
            "$85,675"
        ],
        [
            "Howard Hatfield",
            "Office Manager",
            "San Francisco",
            "7031",
            "2008\/12\/16",
            "$164,500"
        ],
        [
            "Hope Fuentes",
            "Secretary",
            "San Francisco",
            "6318",
            "2010\/02\/12",
            "$109,850"
        ],
        [
            "Vivian Harrell",
            "Financial Controller",
            "San Francisco",
            "9422",
            "2009\/02\/14",
            "$452,500"
        ],
        [
            "Timothy Mooney",
            "Office Manager",
            "London",
            "7580",
            "2008\/12\/11",
            "$136,200"
        ],
        [
            "Jackson Bradshaw",
            "Director",
            "New York",
            "1042",
            "2008\/09\/26",
            "$645,750"
        ],
        [
            "Olivia Liang",
            "Support Engineer",
            "Singapore",
            "2120",
            "2011\/02\/03",
            "$234,500"
        ],
        [
            "Bruno Nash",
            "Software Engineer",
            "London",
            "6222",
            "2011\/05\/03",
            "$163,500"
        ],
        [
            "Sakura Yamamoto",
            "Support Engineer",
            "Tokyo",
            "9383",
            "2009\/08\/19",
            "$139,575"
        ],
        [
            "Thor Walton",
            "Developer",
            "New York",
            "8327",
            "2013\/08\/11",
            "$98,540"
        ],
        [
            "Finn Camacho",
            "Support Engineer",
            "San Francisco",
            "2927",
            "2009\/07\/07",
            "$87,500"
        ],
        [
            "Serge Baldwin",
            "Data Coordinator",
            "Singapore",
            "8352",
            "2012\/04\/09",
            "$138,575"
        ],
        [
            "Zenaida Frank",
            "Software Engineer",
            "New York",
            "7439",
            "2010\/01\/04",
            "$125,250"
        ],
        [
            "Zorita Serrano",
            "Software Engineer",
            "San Francisco",
            "4389",
            "2012\/06\/01",
            "$115,000"
        ],
        [
            "Jennifer Acosta",
            "Junior Javascript Developer",
            "Edinburgh",
            "3431",
            "2013\/02\/01",
            "$75,650"
        ],
        [
            "Cara Stevens",
            "Sales Assistant",
            "New York",
            "3990",
            "2011\/12\/06",
            "$145,600"
        ],
        [
            "Hermione Butler",
            "Regional Director",
            "London",
            "1016",
            "2011\/03\/21",
            "$356,250"
        ],
        [
            "Lael Greer",
            "Systems Administrator",
            "London",
            "6733",
            "2009\/02\/27",
            "$103,500"
        ],
        [
            "Jonas Alexander",
            "Developer",
            "San Francisco",
            "8196",
            "2010\/07\/14",
            "$86,500"
        ],
        [
            "Shad Decker",
            "Regional Director",
            "Edinburgh",
            "6373",
            "2008\/11\/13",
            "$183,000"
        ],
        [
            "Michael Bruce",
            "Javascript Developer",
            "Singapore",
            "5384",
            "2011\/06\/27",
            "$183,000"
        ],
        [
            "Donna Snider",
            "Customer Support",
            "New York",
            "4226",
            "2011\/01\/25",
            "$112,000"
        ]
    ]


$scope.dataTableOpt = {
  //if any ajax call 
  };
});
</script>
<div class="container" ng-app="formvalid">
      <div class="panel" data-ng-controller="validationCtrl">
      <div class="panel-heading border">    
        <h2>Data table using jquery datatable in Angularjs </h2>
      </div>
      <div class="panel-body">
          <table class="table table-bordered bordered table-striped table-condensed datatable" ui-jq="dataTable" ui-options="dataTableOpt">
          <thead>
            <tr>
              <th>#</th>
              <th>Name</th>
              <th>Position</th>
              <th>Office</th>
              <th>Age</th>
              <th>Start Date</th>
            </tr>
          </thead>
            <tbody>
              <tr ng-repeat="n in data">
                <td>{{$index+1}}</td>
                <td>{{n[0]}}</td>
                <td>{{n[1]}}</td>
                <td>{{n[2]}}</td>
                <td>{{n[3]}}</td>
                <td>{{n[4] | date:'dd/MM/yyyy'}}</td>
              </tr>
            </tbody>
        </table>
      </div>
    </div>
    </div>

OpenCV error: the function is not implemented

If it's giving you errors with gtk, try qt.

sudo apt-get install libqt4-dev
cmake -D WITH_QT=ON ..
make
sudo make install

If this doesn't work, there's an easy way out.

sudo apt-get install libopencv-*

This will download all the required dependencies(although it seems that you have all the required libraries installed, but still you could try it once). This will probably install OpenCV 2.3.1 (Ubuntu 12.04). But since you have OpenCV 2.4.3 in /usr/local/lib include this path in /etc/ld.so.conf and do ldconfig. So now whenever you use OpenCV, you'd use the latest version. This is not the best way to do it but if you're still having problems with qt or gtk, try this once. This should work.

Update - 18th Jun 2019

I got this error on my Ubuntu(18.04.1 LTS) system for openCV 3.4.2, as the method call to cv2.imshow was failing (e.g., at the line of cv2.namedWindow(name) with error: cv2.error: OpenCV(3.4.2). The function is not implemented.). I am using anaconda. Just the below 2 steps helped me resolve:

conda remove opencv
conda install -c conda-forge opencv=4.1.0

If you are using pip, you can try

pip install opencv-contrib-python

How to list the contents of a package using YUM?

There is a package called yum-utils that builds on YUM and contains a tool called repoquery that can do this.

$ repoquery --help | grep -E "list\ files" 
  -l, --list            list files in this package/group

Combined into one example:

$ repoquery -l time
/usr/bin/time
/usr/share/doc/time-1.7
/usr/share/doc/time-1.7/COPYING
/usr/share/doc/time-1.7/NEWS
/usr/share/doc/time-1.7/README
/usr/share/info/time.info.gz

On at least one RH system, with rpm v4.8.0, yum v3.2.29, and repoquery v0.0.11, repoquery -l rpm prints nothing.

If you are having this issue, try adding the --installed flag: repoquery --installed -l rpm.


DNF Update:

To use dnf instead of yum-utils, use the following command:

$ dnf repoquery -l time
/usr/bin/time
/usr/share/doc/time-1.7
/usr/share/doc/time-1.7/COPYING
/usr/share/doc/time-1.7/NEWS
/usr/share/doc/time-1.7/README
/usr/share/info/time.info.gz

Android SDK installation doesn't find JDK

Yeah install the 32 bit version of the Java SE SDK (or any of the combinations). That should help solve your problem.

Difference between "managed" and "unmanaged"

This is more general than .NET and Windows. Managed is an environment where you have automatic memory management, garbage collection, type safety, ... unmanaged is everything else. So for example .NET is a managed environment and C/C++ is unmanaged.

How to determine whether code is running in DEBUG / RELEASE build?

In xcode 7, there is a field under Apple LLVM 7.0 - preprocessing, which called "Preprocessors Macros Not Used In Precompiled..." I put DEBUG in front of Debug and it works for me by using below code:

#ifdef DEBUG
    NSString* const kURL = @"http://debug.com";
#else
    NSString* const kURL = @"http://release.com";
#endif

MySQLi prepared statements error reporting

Each method of mysqli can fail. You should test each return value. If one fails, think about whether it makes sense to continue with an object that is not in the state you expect it to be. (Potentially not in a "safe" state, but I think that's not an issue here.)

Since only the error message for the last operation is stored per connection/statement you might lose information about what caused the error if you continue after something went wrong. You might want to use that information to let the script decide whether to try again (only a temporary issue), change something or to bail out completely (and report a bug). And it makes debugging a lot easier.

$stmt = $mysqli->prepare("INSERT INTO testtable VALUES (?,?,?)");
// prepare() can fail because of syntax errors, missing privileges, ....
if ( false===$stmt ) {
  // and since all the following operations need a valid/ready statement object
  // it doesn't make sense to go on
  // you might want to use a more sophisticated mechanism than die()
  // but's it's only an example
  die('prepare() failed: ' . htmlspecialchars($mysqli->error));
}

$rc = $stmt->bind_param('iii', $x, $y, $z);
// bind_param() can fail because the number of parameter doesn't match the placeholders in the statement
// or there's a type conflict(?), or ....
if ( false===$rc ) {
  // again execute() is useless if you can't bind the parameters. Bail out somehow.
  die('bind_param() failed: ' . htmlspecialchars($stmt->error));
}

$rc = $stmt->execute();
// execute() can fail for various reasons. And may it be as stupid as someone tripping over the network cable
// 2006 "server gone away" is always an option
if ( false===$rc ) {
  die('execute() failed: ' . htmlspecialchars($stmt->error));
}

$stmt->close();

Just a few notes six years later...

The mysqli extension is perfectly capable of reporting operations that result in an (mysqli) error code other than 0 via exceptions, see mysqli_driver::$report_mode.
die() is really, really crude and I wouldn't use it even for examples like this one anymore.
So please, only take away the fact that each and every (mysql) operation can fail for a number of reasons; even if the exact same thing went well a thousand times before....

Validate phone number using javascript

Add a $ to the end of the regex to signify the end of the pattern:

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

Cannot find R.layout.activity_main

in 2019 I faced the same problem and I searched the internet and found the following which I am sharing with all.

In android studio letter R stands for the resources and this error occurs because of the build process not able to sync resources with your project. In other words, this error is caused when Android Studio can’t generate your R.java file correctly. This problem happens when you shift code to another system or while building the android project for the first time. So when you create a new activity or new class you will see an error message like “cannot resolve symbol r” with a red underline.

Below you can find the possible ways to fix cannot resolve symbol r in android studio.

Update Project Gradle To Latest Version Always use the latest version of Gradle to work android studio properly.

Sync Project With Gradle File Once you update the Gradle plugin you need to sync project with the Gradle file. Open android studio and click on Files > Sync Project with Gradle Files option.

Clean and Rebuild Project The most effective solution is the simplest: clean and rebuild your project. Select Build > Clean Project from the Android Studio toolbar, wait a few moments, and then build your project by selecting Build > Rebuild Project.

Invalidate Caches / Restart If you encounter this error after moving some files and directories around, then it’s possible that the R.layout error is being caused by a mismatch between Android Studio’s cache and your project’s current layout. If you suspect this may be the case, then select File > Invalidate Caches / Restart > Invalidate and Restart from Android Studio’s toolbar. Issues with the names of your resources can also prevent the R.java file from being created correctly, so check that you don't have multiple resources with the same name and that none of your file names contain invalid characters. Android Studio only supports lowercase a-z, 0-9, full stops and underscores, and a single invalid character can cause an R.layout error across your entire project, even if you don’t actually use this resource anywhere in your project!

My problem and its solution: In my case, I applied all the above but could not solve the problem. Thus I started a new project and pasted my code one by one and validated my code with running the app. Finally, at one point when I first deleted the code in colors.xml and copied and pasted code below in colors.xml file, I got the error.

<color name="bg_login">#26ae90</color>
<color name="bg_register">#2e3237</color>
<color name="bg_main">#428bca</color>
<color name="white">#ffffff</color>
<color name="input_login">#222222</color>
<color name="input_login_hint">#999999</color>
<color name="input_register">#888888</color>
<color name="input_register_bg">#3b4148</color>
<color name="input_register_hint">#5e6266</color>
<color name="btn_login">#26ae90</color>
<color name="btn_login_bg">#eceef1</color>
<color name="lbl_name">#333333</color>
<color name="btn_logut_bg">#ff6861</color>

when I undo my changes the error vanished again. Thus my code in colors.xml is not the code above and the code already in colors.xml i.e

<color name="colorPrimary">#008577</color>
<color name="colorPrimaryDark">#00574B</color>
<color name="colorAccent">#D81B60</color>
<color name="bg_login">#26ae90</color>
<color name="bg_register">#2e3237</color>
<color name="bg_main">#428bca</color>
<color name="white">#ffffff</color>
<color name="input_login">#222222</color>
<color name="input_login_hint">#999999</color>
<color name="input_register">#888888</color>
<color name="input_register_bg">#3b4148</color>
<color name="input_register_hint">#5e6266</color>
<color name="btn_login">#26ae90</color>
<color name="btn_login_bg">#eceef1</color>
<color name="lbl_name">#333333</color>
<color name="btn_logut_bg">#ff6861</color>

"Maybe its because i did not have color primary defined" Hope it will help someone like me who is new in programming.

Fatal error: Call to undefined function mcrypt_encrypt()

On ubuntu 14.10 :

Install module mcrypt

sudo apt install php5-mcrypt

Enable module mcrypt on apache2

sudo a2enmod mcrypt

Reload module configuration

sudo service apache2 restart

Converting java date to Sql timestamp

Take a look at SimpleDateFormat:

java.util.Date utilDate = new java.util.Date();
java.sql.Timestamp sq = new java.sql.Timestamp(utilDate.getTime());  

SimpleDateFormat sdf = new SimpleDateFormat("dd.MM.yyyy HH:mm:ss");
System.out.println(sdf.format(sq));

Selenium and xPath - locating a link by containing text

@FindBy(xpath = "//button[@class='btn btn-primary' and contains(text(), 'Submit')]") private WebElementFacade submitButton;

public void clickOnSubmitButton() {
    submitButton.click();
}   

JavaScript: Collision detection

You can try jquery-collision. Full disclosure: I just wrote this and released it. I didn't find a solution, so I wrote it myself.

It allows you to do:

var hit_list = $("#ball").collision("#someobject0");

which will return all the "#someobject0"'s that overlap with "#ball".

Winforms issue - Error creating window handle

The out of memory suggestion doesn't seem like a bad lead.

What is your program doing that it gets this error?

Is it creating a great many windows or controls? Does it create them programatically as opposed to at design time? If so, do you do this in a loop? Is that loop infinite? Are you consuming staggering boatloads of memory in some other way?

What happens when you watch the memory used by your application in task manager? Does it skyrocket to the moon? Or better yet, as suggested above use process monitor to dive into the details.

Fastest way to remove non-numeric characters from a VARCHAR in SQL Server

I'd use an Inline Function from performance perspective, see below: Note that symbols like '+','-' etc will not be removed

CREATE FUNCTION [dbo].[UDF_RemoveNumericStringsFromString]
 (
 @str varchar(100)
 )
 RETURNS TABLE AS RETURN
 WITH Tally (n) as 
  (
  -- 100 rows
   SELECT TOP (Len(@Str)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
   FROM (VALUES (0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) a(n)
   CROSS JOIN (VALUES(0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) b(n)
  )

  SELECT OutStr =  STUFF(
       (SELECT SUBSTRING(@Str, n,1) st
        FROM Tally
        WHERE ISNUMERIC(SUBSTRING(@Str, n,1)) = 1
        FOR XML PATH(''),type).value('.', 'varchar(100)'),1,0,'')
  GO

  /*Use it*/
  SELECT OutStr
  FROM dbo.UDF_RemoveNumericStringsFromString('fjkfhk759734977fwe9794t23')
  /*Result set
   759734977979423 */

You can define it with more than 100 characters...

Placeholder Mixin SCSS/CSS

This is for shorthand syntax

=placeholder
  &::-webkit-input-placeholder
    @content
  &:-moz-placeholder
    @content
  &::-moz-placeholder
    @content
  &:-ms-input-placeholder
    @content

use it like

input
  +placeholder
    color: red

Remove all the children DOM elements in div

while (node.hasChildNodes()) {
    node.removeChild(node.lastChild);
}

ASP.Net MVC Redirect To A Different View

You can use the RedirectToAction() method, then the action you redirect to can return a View. The easiest way to do this is:

return RedirectToAction("Index", model);

Then in your Index method, return the view you want.

Ansible playbook shell output

I found using the minimal stdout_callback with ansible-playbook gave similar output to using ad-hoc ansible.

In your ansible.cfg (Note that I'm on OS X so modify the callback_plugins path to suit your install)

stdout_callback     = minimal
callback_plugins    = /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/ansible/plugins/callback

So that a ansible-playbook task like yours

---
-
  hosts: example
  gather_facts: no
  tasks:
    - shell: ps -eo pcpu,user,args | sort -r -k1 | head -n5

Gives output like this, like an ad-hoc command would

example | SUCCESS | rc=0 >>
%CPU USER     COMMAND
 0.2 root     sshd: root@pts/3
 0.1 root     /usr/sbin/CROND -n
 0.0 root     [xfs-reclaim/vda]
 0.0 root     [xfs_mru_cache]

I'm using ansible-playbook 2.2.1.0

Add space between <li> elements

I just want to say guys:

Only Play With Margin

It is a lot easier to add space between <li> if you play with margin.

How to filter Android logcat by application?

Add your application's package in "Filter Name" by clicking on "+" button on left top corner in logcat.

Rails :include vs. :joins

I was recently reading more on difference between :joins and :includes in rails. Here is an explaination of what I understood (with examples :))

Consider this scenario:

  • A User has_many comments and a comment belongs_to a User.

  • The User model has the following attributes: Name(string), Age(integer). The Comment model has the following attributes:Content, user_id. For a comment a user_id can be null.

Joins:

:joins performs a inner join between two tables. Thus

Comment.joins(:user)

#=> <ActiveRecord::Relation [#<Comment id: 1, content: "Hi I am Aaditi.This is my first   comment!", user_id: 1, created_at: "2014-11-12 18:29:24", updated_at: "2014-11-12 18:29:24">, 
     #<Comment id: 2, content: "Hi I am Ankita.This is my first comment!", user_id: 2, created_at: "2014-11-12 18:29:29", updated_at: "2014-11-12 18:29:29">,    
     #<Comment id: 3, content: "Hi I am John.This is my first comment!", user_id: 3, created_at: "2014-11-12 18:30:25", updated_at: "2014-11-12 18:30:25">]>

will fetch all records where user_id (of comments table) is equal to user.id (users table). Thus if you do

Comment.joins(:user).where("comments.user_id is null")

#=> <ActiveRecord::Relation []>

You will get a empty array as shown.

Moreover joins does not load the joined table in memory. Thus if you do

comment_1 = Comment.joins(:user).first

comment_1.user.age
#=>?[1m?[36mUser Load (0.0ms)?[0m  ?[1mSELECT "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT 1?[0m  [["id", 1]]
#=> 24

As you see, comment_1.user.age will fire a database query again in the background to get the results

Includes:

:includes performs a left outer join between the two tables. Thus

Comment.includes(:user)

#=><ActiveRecord::Relation [#<Comment id: 1, content: "Hi I am Aaditi.This is my first comment!", user_id: 1, created_at: "2014-11-12 18:29:24", updated_at: "2014-11-12 18:29:24">,
   #<Comment id: 2, content: "Hi I am Ankita.This is my first comment!", user_id: 2, created_at: "2014-11-12 18:29:29", updated_at: "2014-11-12 18:29:29">,
   #<Comment id: 3, content: "Hi I am John.This is my first comment!", user_id: 3, created_at: "2014-11-12 18:30:25", updated_at: "2014-11-12 18:30:25">,    
   #<Comment id: 4, content: "Hi This is an anonymous comment!", user_id: nil, created_at: "2014-11-12 18:31:02", updated_at: "2014-11-12 18:31:02">]>

will result in a joined table with all the records from comments table. Thus if you do

Comment.includes(:user).where("comment.user_id is null")
#=> #<ActiveRecord::Relation [#<Comment id: 4, content: "Hi This is an anonymous comment!", user_id: nil, created_at: "2014-11-12 18:31:02", updated_at: "2014-11-12 18:31:02">]>

it will fetch records where comments.user_id is nil as shown.

Moreover includes loads both the tables in the memory. Thus if you do

comment_1 = Comment.includes(:user).first

comment_1.user.age
#=> 24

As you can notice comment_1.user.age simply loads the result from memory without firing a database query in the background.

Class has been compiled by a more recent version of the Java Environment

53 stands for java-9, so it means that whatever class you have has been compiled with javac-9 and you try to run it with jre-8. Either re-compile that class with javac-8 or use the jre-9

Python - List of unique dictionaries

Since the id is sufficient for detecting duplicates, and the id is hashable: run 'em through a dictionary that has the id as the key. The value for each key is the original dictionary.

deduped_dicts = dict((item["id"], item) for item in list_of_dicts).values()

In Python 3, values() doesn't return a list; you'll need to wrap the whole right-hand-side of that expression in list(), and you can write the meat of the expression more economically as a dict comprehension:

deduped_dicts = list({item["id"]: item for item in list_of_dicts}.values())

Note that the result likely will not be in the same order as the original. If that's a requirement, you could use a Collections.OrderedDict instead of a dict.

As an aside, it may make a good deal of sense to just keep the data in a dictionary that uses the id as key to begin with.

In Python how should I test if a variable is None, True or False

Don't fear the Exception! Having your program just log and continue is as easy as:

try:
    result = simulate(open("myfile"))
except SimulationException as sim_exc:
    print "error parsing stream", sim_exc
else:
    if result:
        print "result pass"
    else:
        print "result fail"

# execution continues from here, regardless of exception or not

And now you can have a much richer type of notification from the simulate method as to what exactly went wrong, in case you find error/no-error not to be informative enough.

How can I drop a table if there is a foreign key constraint in SQL Server?

You have to drop the constraint before drop your table.

You can use those queries to find all FKs in your table and find the FKs in the tables in which your table is used.

Declare @SchemaName VarChar(200) = 'Your Schema name'
Declare @TableName VarChar(200) = 'Your Table Name'

-- Find FK in This table.
SELECT 
    ' IF  EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = 
OBJECT_ID(N''' + 
      '[' + OBJECT_SCHEMA_NAME(FK.parent_object_id) + '].[' + FK.name + ']'
+ ''') AND parent_object_id = OBJECT_ID(N''' + 
      '[' + OBJECT_SCHEMA_NAME(FK.parent_object_id) + '].[' + 
OBJECT_NAME(FK.parent_object_id) + ']' + ''')) ' +

    'ALTER TABLE ' +  OBJECT_SCHEMA_NAME(FK.parent_object_id) +
    '.[' + OBJECT_NAME(FK.parent_object_id) + 
    '] DROP CONSTRAINT ' + FK.name
    , S.name , O.name, OBJECT_NAME(FK.parent_object_id)
FROM sys.foreign_keys AS FK
INNER JOIN Sys.objects As O 
  ON (O.object_id = FK.parent_object_id )
INNER JOIN SYS.schemas AS S 
  ON (O.schema_id = S.schema_id)  
WHERE 
      O.name = @TableName
      And S.name = @SchemaName


-- Find the FKs in the tables in which this table is used
  SELECT 
    ' IF  EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id =   
      OBJECT_ID(N''' + 
      '[' + OBJECT_SCHEMA_NAME(FK.parent_object_id) + '].[' + FK.name + ']'
  + ''') AND parent_object_id = OBJECT_ID(N''' + 
      '[' + OBJECT_SCHEMA_NAME(FK.parent_object_id) + '].[' + 
 OBJECT_NAME(FK.parent_object_id) + ']' + ''')) ' +

    ' ALTER TABLE ' +  OBJECT_SCHEMA_NAME(FK.parent_object_id) +
    '.[' + OBJECT_NAME(FK.parent_object_id) + 
    '] DROP CONSTRAINT ' + FK.name
    , S.name , O.name, OBJECT_NAME(FK.parent_object_id)
FROM sys.foreign_keys AS FK
INNER JOIN Sys.objects As O 
  ON (O.object_id = FK.referenced_object_id )
INNER JOIN SYS.schemas AS S 
  ON (O.schema_id = S.schema_id)  
WHERE 
      O.name = @TableName
      And S.name = @SchemaName 

Convert from ASCII string encoded in Hex to plain ASCII?

No need to import any library:

>>> bytearray.fromhex("7061756c").decode()
'paul'

Track a new remote branch created on GitHub

git fetch
git branch --track branch-name origin/branch-name

First command makes sure you have remote branch in local repository. Second command creates local branch which tracks remote branch. It assumes that your remote name is origin and branch name is branch-name.

--track option is enabled by default for remote branches and you can omit it.

Access denied for user 'root'@'localhost' (using password: YES) (Mysql::Error)

I got this problem today while installing SugarCRM (a free CRM).

The system was not able to connect to the database using the root user. I could definitively log in as root from the console... so what was the problem?

I found out that in my situation, I was getting exactly the same error, but that was because the password was sent to mysql directly from the $_POST data, in other words, the < character from my password was sent to mysql as &lt; which means the password was wrong.

Everything else did not help a bit. The list of users in mysql were correct, including the anonymous user (which appears after the root entries.)

How to find all trigger associated with a table with SQL Server?

select * from information_schema.TRIGGERS;

Define css class in django Forms

You could also use Django Crispy Forms, it's a great tool to define forms in case you'd like to use some CSS framework like Bootstrap or Foundation. And it's easy to specify classes for your form fields there.

Your form class would like this then:

from django import forms

from crispy_forms.helper import FormHelper
from crispy_forms.layout import Layout, Div, Submit, Field
from crispy_forms.bootstrap import FormActions

class SampleClass(forms.Form):
    name = forms.CharField(max_length=30)
    age = forms.IntegerField()
    django_hacker = forms.BooleanField(required=False)

    helper = FormHelper()
    helper.form_class = 'your-form-class'
    helper.layout = Layout(
        Field('name', css_class='name-class'),
        Field('age', css_class='age-class'),
        Field('django_hacker', css-class='hacker-class'),
        FormActions(
            Submit('save_changes', 'Save changes'),
        )
    )

Convert object of any type to JObject with Json.NET

This will work:

var cycles = cycleSource.AllCycles();

var settings = new JsonSerializerSettings
{
    ContractResolver = new CamelCasePropertyNamesContractResolver()
};

var vm = new JArray();

foreach (var cycle in cycles)
{
    var cycleJson = JObject.FromObject(cycle);
    // extend cycleJson ......
    vm.Add(cycleJson);
}

return vm;

Can't find bundle for base name

BalusC is right. Version 1.0.13 is current, but 1.0.9 appears to have the required bundles:

$ jar tf lib/jfreechart-1.0.9.jar | grep LocalizationBundle.properties 
org/jfree/chart/LocalizationBundle.properties
org/jfree/chart/editor/LocalizationBundle.properties
org/jfree/chart/plot/LocalizationBundle.properties

How to use global variables in React Native?

You can consider leveraging React's Context feature.

class NavigationContainer extends React.Component {
    constructor(props) {
        super(props);
        this.goTo = this.goTo.bind(this);
    }
    goTo(location) {
        ...
    }
    getChildContext() {
        // returns the context to pass to children
        return {
            goTo: this.goTo
        }
    }
    ...
}

// defines the context available to children
NavigationContainer.childContextTypes = {
    goTo: PropTypes.func
}

class SomeViewContainer extends React.Component {
    render() {
        // grab the context provided by ancestors
        const {goTo} = this.context;
        return <button onClick={evt => goTo('somewhere')}>
            Hello
        </button>
    }
}

// Define the context we want from ancestors
SomeViewContainer.contextTypes = {
    goTo: PropTypes.func
}

With context, you can pass data through the component tree without having to pass the props down manually at every level. There is a big warning on this being an experimental feature and may break in the future, but I would imagine this feature to be around given the majority of the popular frameworks like Redux use context extensively.

The main advantage of using context v.s. a global variable is context is "scoped" to a subtree (this means you can define different scopes for different subtrees).

Do note that you should not pass your model data via context, as changes in context will not trigger React's component render cycle. However, I do find it useful in some use case, especially when implementing your own custom framework or workflow.

make an html svg object also a clickable link

Do it with javascript and add a onClick-attribute to your object-element:

<object data="mysvg.svg" type="image/svg+xml" onClick="window.location.href='http://google.at';">
    <span>Your browser doesn't support SVG images</span>
</object>

How to: Create trigger for auto update modified date with SQL Server 2008

My approach:

  • define a default constraint on the ModDate column with a value of GETDATE() - this handles the INSERT case

  • have a AFTER UPDATE trigger to update the ModDate column

Something like:

CREATE TRIGGER trg_UpdateTimeEntry
ON dbo.TimeEntry
AFTER UPDATE
AS
    UPDATE dbo.TimeEntry
    SET ModDate = GETDATE()
    WHERE ID IN (SELECT DISTINCT ID FROM Inserted)

How to import RecyclerView for Android L-preview

Other answers did not work for me. I had to add this line:

compile 'com.android.support:recyclerview-v7:21.0.0'

Deploying Java webapp to Tomcat 8 running in Docker container

You are trying to copy the war file to a directory below webapps. The war file should be copied into the webapps directory.

Remove the mkdir command, and copy the war file like this:

COPY /1.0-SNAPSHOT/my-app-1.0-SNAPSHOT.war /usr/local/tomcat/webapps/myapp.war

Tomcat will extract the war if autodeploy is turned on.

Automate scp file transfer using a shell script

If you are ok with entering your password once for every run of the script, you can do so easily using an SSH master connection.

#!/usr/bin/env bash

USER_AT_HOST="user@host"  # use "$1@$2" here if you like
SSHSOCKET=~/".ssh/$USER_AT_HOST"

# This is the only time you have to enter the password:
# Open master connection:
ssh -M -f -N -o ControlPath="$SSHSOCKET" "$USER_AT_HOST"

# These do not prompt for your password:
scp -o ControlPath="$SSHSOCKET" file1.xy "$USER_AT_HOST":remotefile1.xy
scp -o ControlPath="$SSHSOCKET" file2.xy "$USER_AT_HOST":remotefile2.xy

# You can also use the flag for normal ssh:
ssh -o ControlPath="$SSHSOCKET" "$USER_AT_HOST" "echo hello"
ssh -o ControlPath="$SSHSOCKET" "$USER_AT_HOST" "echo world"

# Close master connection:
ssh -S "$SSHSOCKET" -O exit "$USER_AT_HOST"

Access Control Request Headers, is added to header in AJAX request with jQuery

What you saw in Firefox was not the actual request; note that the HTTP method is OPTIONS, not POST. It was actually the 'pre-flight' request that the browser makes to determine whether a cross-domain AJAX request should be allowed:

http://www.w3.org/TR/cors/

The Access-Control-Request-Headers header in the pre-flight request includes the list of headers in the actual request. The server is then expected to report back whether these headers are supported in this context or not, before the browser submits the actual request.

How to pass data using NotificationCenter in swift 3.0 and NSNotificationCenter in swift 2.0?

this is how I implement it .

let dictionary = self.convertStringToDictionary(responceString)            
     NotificationCenter.default.post(name: NSNotification.Name(rawValue: "SOCKET_UPDATE"), object: dictionary)

curl usage to get header

You need to add the -i flag to the first command, to include the HTTP header in the output. This is required to print headers.

curl -X HEAD -i http://www.google.com

More here: https://serverfault.com/questions/140149/difference-between-curl-i-and-curl-x-head