Programs & Examples On #Datahistory

Safely override C++ virtual functions

Your compiler may have a warning that it can generate if a base class function becomes hidden. If it does, enable it. That will catch const clashes and differences in parameter lists. Unfortunately this won't uncover a spelling error.

For example, this is warning C4263 in Microsoft Visual C++.

Django URLs TypeError: view must be a callable or a list/tuple in the case of include()

Your code is

urlpatterns = [
    url(r'^$', 'myapp.views.home'),
    url(r'^contact/$', 'myapp.views.contact'),
    url(r'^login/$', 'django.contrib.auth.views.login'),
]

change it to following as you're importing include() function :

urlpatterns = [
    url(r'^$', views.home),
    url(r'^contact/$', views.contact),
    url(r'^login/$', views.login),
]

How can I find out the total physical memory (RAM) of my linux box suitable to be parsed by a shell script?

I find htop a useful tool.

sudo apt-get install htop

and then

free -m

will give the information you need.

Javascript sleep/delay/wait function

The behavior exact to the one specified by you is impossible in JS as implemented in current browsers. Sorry.

Well, you could in theory make a function with a loop where loop's end condition would be based on time, but this would hog your CPU, make browser unresponsive and would be extremely poor design. I refuse to even write an example for this ;)


Update: My answer got -1'd (unfairly), but I guess I could mention that in ES6 (which is not implemented in browsers yet, nor is it enabled in Node.js by default), it will be possible to write a asynchronous code in a synchronous fashion. You would need promises and generators for that.

You can use it today, for instance in Node.js with harmony flags, using Q.spawn(), see this blog post for example (last example there).

Android Closing Activity Programmatically

You Can use just finish(); everywhere after Activity Start for clear that Activity from Stack.

How to assert two list contain the same elements in Python?

As of Python 3.2 unittest.TestCase.assertItemsEqual(doc) has been replaced by unittest.TestCase.assertCountEqual(doc) which does exactly what you are looking for, as you can read from the python standard library documentation. The method is somewhat misleadingly named but it does exactly what you are looking for.

a and b have the same elements in the same number, regardless of their order

Here a simple example which compares two lists having the same elements but in a different order.

  • using assertCountEqual the test will succeed
  • using assertListEqual the test will fail due to the order difference of the two lists

Here a little example script.

import unittest


class TestListElements(unittest.TestCase):
    def setUp(self):
        self.expected = ['foo', 'bar', 'baz']
        self.result = ['baz', 'foo', 'bar']

    def test_count_eq(self):
        """Will succeed"""
        self.assertCountEqual(self.result, self.expected)

    def test_list_eq(self):
        """Will fail"""
        self.assertListEqual(self.result, self.expected)

if __name__ == "__main__":
    unittest.main()

Side Note : Please make sure that the elements in the lists you are comparing are sortable.

Git push existing repo to a new and different remote repo server?

Do you really want to simply push your local repository (with its local branches, etc.) to the new remote or do you really want to mirror the old remote (with all its branches, tags, etc) on the new remote? If the latter here's a great blog on How to properly mirror a git repository.

I strongly encourage you to read the blog for some very important details, but the short version is this:

In a new directory run these commands:

git clone --mirror [email protected]/upstream-repository.git
cd upstream-repository.git
git push --mirror [email protected]/new-location.git

How can I install a .ipa file to my iPhone simulator

You cannot run an ipa file in the simulator because the ipa file is compiled for a phone's ARM architecture, not the simulator's x86 architecture.

However, you can extract an app installed in a local simulator, send it to someone else, and have them copy it to the simulator on their machine.

In terminal, type:

open ~/Library/Application\ Support/iPhone\ Simulator/*/Applications

This will open all the applications folders of all the simulators you have installed. Each of the applications will be in a folder with a random hexadecimal name. You can work out which is your application by looking inside each of them. Once you have found out which one you want, right click it and choose "Compress ..." and it will make a zip file that you can easily copy to another computer and unzip to a similar location.

How can I get Docker Linux container information from within the container itself?

To make it simple,

  1. Container ID is your host name inside docker
  2. Container information is available inside /proc/self/cgroup

To get host name,

hostname

or

uname -n

or

cat /etc/host

Output can be redirected to any file & read back from application E.g.: # hostname > /usr/src//hostname.txt

Add border-bottom to table row <tr>

I found when using this method that the space between the td elements caused a gap to form in the border, but have no fear...

One way around this:

<tr>
    <td>
        Example of normal table data
    </td>

    <td class="end" colspan="/* total number of columns in entire table*/">
        /* insert nothing in here */ 
    </td>
</tr>

With the CSS:

td.end{
    border:2px solid black;
}

Laravel: Using try...catch with DB::transaction()

You could wrapping the transaction over try..catch or even reverse them, here my example code I used to in laravel 5,, if you look deep inside DB:transaction() in Illuminate\Database\Connection that the same like you write manual transaction.

Laravel Transaction

public function transaction(Closure $callback)
    {
        $this->beginTransaction();

        try {
            $result = $callback($this);

            $this->commit();
        }

        catch (Exception $e) {
            $this->rollBack();

            throw $e;
        } catch (Throwable $e) {
            $this->rollBack();

            throw $e;
        }

        return $result;
    }

so you could write your code like this, and handle your exception like throw message back into your form via flash or redirect to another page. REMEMBER return inside closure is returned in transaction() so if you return redirect()->back() it won't redirect immediately, because the it returned at variable which handle the transaction.

Wrap Transaction

$result = DB::transaction(function () use ($request, $message) {
   try{

      // execute query 1
      // execute query 2
      // ..

      return redirect(route('account.article'));

   } catch (\Exception $e) {
       return redirect()->back()->withErrors(['error' => $e->getMessage()]);
    }
 });

// redirect the page
return $result;

then the alternative is throw boolean variable and handle redirect outside transaction function or if your need to retrieve why transaction failed you can get it from $e->getMessage() inside catch(Exception $e){...}

Close a div by clicking outside

Add a transparent background taking up the whole window size, just before your popup div

.transparent-back{
    position: fixed;
    top: 0px;
    left:0px;
    width: 100%;
    height: 100%;
    background-color: rgba(255,255,255,0.5);
}

Then on its click, dismiss the popup.

$(".transparent-back").on('click',function(){
    $('popup').fadeOut(300);
});

Postgresql SELECT if string contains

I personally prefer the simpler syntax of the ~ operator.

SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' ~ tag_name;

Worth reading through Difference between LIKE and ~ in Postgres to understand the difference. `

Paused in debugger in chrome?

If you navigate to Sources you can see the pauseenter image description here button at the bottom of the DevTools. Basically there are 3 possible pause option in DevTools while debugging js file,

  • Don't pause on exceptions(enter image description here) :

    The pause button will be in grey colour as if "Don't pause on exceptions" is active. enter image description here

  • Pause on all exceptions(enter image description here) :

    The pause button will be in blue colour as if "Pause on all exceptions" is active. enter image description here

  • Pause on uncaught exceptions(enter image description here) :

    The pause button will be in purple colour as if "Pause on uncaught exceptions" is active. enter image description here

In your case, if you don't want to pause, select Don't pause on exceptions. To select, toggle the pause button till it become greyenter image description here.

Multiple definition of ... linker error

Declarations of public functions go in header files, yes, but definitions are absolutely valid in headers as well! You may declare the definition as static (only 1 copy allowed for the entire program) if you are defining things in a header for utility functions that you don't want to have to define again in each c file. I.E. defining an enum and a static function to translate the enum to a string. Then you won't have to rewrite the enum to string translator for each .c file that includes the header. :)

Read XML file using javascript

You can use below script for reading child of the above xml. It will work with IE and Mozila Firefox both.

<script type="text/javascript">

function readXml(xmlFile){

var xmlDoc;

if(typeof window.DOMParser != "undefined") {
    xmlhttp=new XMLHttpRequest();
    xmlhttp.open("GET",xmlFile,false);
    if (xmlhttp.overrideMimeType){
        xmlhttp.overrideMimeType('text/xml');
    }
    xmlhttp.send();
    xmlDoc=xmlhttp.responseXML;
}
else{
    xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
    xmlDoc.async="false";
    xmlDoc.load(xmlFile);
}
var tagObj=xmlDoc.getElementsByTagName("marker");
var typeValue = tagObj[0].getElementsByTagName("type")[0].childNodes[0].nodeValue;
var titleValue = tagObj[0].getElementsByTagName("title")[0].childNodes[0].nodeValue;
}
</script>

how to get login option for phpmyadmin in xampp

Step 1:

Locate phpMyAdmin installation path.

Step 2:

Open phpMyAdmin/config.inc.php in your favourite text editor. Copy config.sample.inc.php to config.inc.php if it's missing.

Step 3:

Search for $cfg['Servers'][$i]['auth_type'] = 'config';

Replace it with $cfg['Servers'][$i]['auth_type'] = 'cookie';

Angular2 disable button

I think this is the easiest way

<!-- Submit Button-->
<button 
  mat-raised-button       
  color="primary"
  [disabled]="!f.valid"
>
  Submit
</button>

Cleanest way to write retry logic?

Do it simple in C#, Java or other languages:

  internal class ShouldRetryHandler {
    private static int RETRIES_MAX_NUMBER = 3;
    private static int numberTryes;

    public static bool shouldRetry() {
        var statusRetry = false;

        if (numberTryes< RETRIES_MAX_NUMBER) {
            numberTryes++;
            statusRetry = true;
            //log msg -> 'retry number' + numberTryes

        }

        else {
            statusRetry = false;
            //log msg -> 'reached retry number limit' 
        }

        return statusRetry;
    }
}

and use it in your code very simple:

 void simpleMethod(){
    //some code

    if(ShouldRetryHandler.shouldRetry()){
    //do some repetitive work
     }

    //some code    
    }

or you can use it in recursive methods:

void recursiveMethod(){
    //some code

    if(ShouldRetryHandler.shouldRetry()){
    recursiveMethod();
     }

    //some code    
    }

How to center the text in a JLabel?

The following constructor, JLabel(String, int), allow you to specify the horizontal alignment of the label.

JLabel label = new JLabel("The Label", SwingConstants.CENTER);

git clone error: RPC failed; curl 56 OpenSSL SSL_read: SSL_ERROR_SYSCALL, errno 10054

you need to increase the buffer size (it's due to the large repository size), so you have to increase it

git config http.postBuffer 524288000

Althought you must have an initializd repository, just porceed as the following

git init
git config http.postBuffer 524288000
git remote add origin <REPO URL>
git pull origin master
...

Read Post Data submitted to ASP.Net Form

Read the Request.Form NameValueCollection and process your logic accordingly:

NameValueCollection nvc = Request.Form;
string userName, password;
if (!string.IsNullOrEmpty(nvc["txtUserName"]))
{
  userName = nvc["txtUserName"];
}

if (!string.IsNullOrEmpty(nvc["txtPassword"]))
{
  password = nvc["txtPassword"];
}

//Process login
CheckLogin(userName, password);

... where "txtUserName" and "txtPassword" are the Names of the controls on the posting page.

How can I render inline JavaScript with Jade / Pug?

script(nonce="some-nonce").
  console.log("test");

//- Workaround
<script nonce="some-nonce">console.log("test");</script>

How to handle click event in Button Column in Datagridview?

You can try this one, you wouldn't care much about the ordering of the columns.

private void TheGrid_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
    if (TheGrid.Columns[e.ColumnIndex].HeaderText == "Edit")
    {
        // to do: edit actions here
        MessageBox.Show("Edit");
    }
}

How to cast an Object to an int

If you mean cast a String to int, use Integer.valueOf("123").

You can't cast most other Objects to int though, because they wont have an int value. E.g. an XmlDocument has no int value.

Android Studio emulator does not come with Play Store for API 23

Just want to add another solution for React Native users that just need the Expo app.

  1. Install the Expo app
  2. Open you project
  3. Click Device -> Open on Android - In this stage Expo will install the expo android app and you'll be able to open it.

Cygwin Make bash command not found

I faced the same problem. Follow these steps:

  1. Goto the installer once again.
  2. Do the initial setup.
  3. Select all the libraries by clicking and selecting install (the one already installed will show reinstall, so don't install them).
  4. Click next.
  5. The installation will take some time.

Reversing a String with Recursion in Java

Run the code below - it prints:

Step 0: ello / H
Step 1: llo / e
Step 2: lo / l
Step 3: o / l
Step 3 returns: ol
Step 2 returns: oll
Step 1 returns: olle
Step 0 returns: olleH

Code:

public class Test {

    private static int i = 0;

    public static void main(String args[]) {
        reverse("Hello");
    }

    public static String reverse(String str) {
        int localI = i++;
        if ((null == str) || (str.length()  <= 1)) {
            return str;
        }
        System.out.println("Step " + localI + ": " + str.substring(1) + " / " + str.charAt(0));
        String reversed = reverse(str.substring(1)) + str.charAt(0);

        System.out.println("Step " + localI + " returns: " + reversed);
        return reversed;
    }
}

jQuery If DIV Doesn't Have Class "x"

I think the author was looking for:

$(this).not('.selected')

Preventing console window from closing on Visual Studio C/C++ Console application

Here is a way for C/C++:

#include <stdlib.h>

#ifdef _WIN32
    #define WINPAUSE system("pause")
#endif

Put this at the top of your program, and IF it is on a Windows system (#ifdef _WIN32), then it will create a macro called WINPAUSE. Whenever you want your program to pause, call WINPAUSE; and it will pause the program, using the DOS command. For other systems like Unix/Linux, the console should not quit on program exit anyway.

Creating a recursive method for Palindrome

Try this:

package javaapplicationtest;

public class Main {

    public static void main(String[] args) {

        String source = "mango";
        boolean isPalindrome = true;

        //looping through the string and checking char by char from reverse
        for(int loop = 0; loop < source.length(); loop++){          
            if( source.charAt(loop) != source.charAt(source.length()-loop-1)){
                isPalindrome = false;
                break;
            }
        }

         if(isPalindrome == false){
             System.out.println("Not a palindrome");
         }
         else
             System.out.println("Pailndrome");

    }

}

@Media min-width & max-width

for some iPhone you have to put your viewport like this

<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, shrink-to-fit=no, user-scalable=0" />

Creating temporary files in Android

This is what I typically do:

File outputDir = context.getCacheDir(); // context being the Activity pointer
File outputFile = File.createTempFile("prefix", "extension", outputDir);

As for their deletion, I am not complete sure either. Since I use this in my implementation of a cache, I manually delete the oldest files till the cache directory size comes down to my preset value.

Purge Kafka Topic

Temporarily update the retention time on the topic to one second:

kafka-topics.sh --zookeeper <zkhost>:2181 --alter --topic <topic name> --config retention.ms=1000

And in newer Kafka releases, you can also do it with kafka-configs --entity-type topics

kafka-configs.sh --zookeeper <zkhost>:2181 --entity-type topics --alter --entity-name <topic name> --add-config retention.ms=1000

then wait for the purge to take effect (about one minute). Once purged, restore the previous retention.ms value.

Gets last digit of a number

No need to use any strings.Its over burden.

int i = 124;
int last= i%10;
System.out.println(last);   //prints 4

How to set default values for Angular 2 component properties?

Here is the best solution for this. (ANGULAR All Version)

Addressing solution: To set a default value for @Input variable. If no value passed to that input variable then It will take the default value.

I have provided solution for this kind of similar question. You can find the full solution from here

export class CarComponent implements OnInit {
  private _defaultCar: car = {
    // default isCar is true
    isCar: true,
    // default wheels  will be 4
    wheels: 4
  };

  @Input() newCar: car = {};

  constructor() {}

  ngOnInit(): void {

   // this will concate both the objects and the object declared later (ie.. ...this.newCar )
   // will overwrite the default value. ONLY AND ONLY IF DEFAULT VALUE IS PRESENT

    this.newCar = { ...this._defaultCar, ...this.newCar };
   //  console.log(this.newCar);
  }
}

Vertical Menu in Bootstrap

The "nav nav-list" class of Twiter Bootstrap 2.0 is handy for building a side bar.

You can see a lot of documentation at http://www.w3resource.com/twitter-bootstrap/nav-tabs-and-pills-tutorial.php

Hide all elements with class using plain Javascript

Assuming you are dealing with a single class per element:

function swapCssClass(a,b) {
    while (document.querySelector('.' + a)) {
        document.querySelector('.' + a).className = b;
    }
}

and then call simply call it with

swapCssClass('x_visible','x_hidden');

How do I combine the first character of a cell with another cell in Excel?

Personally I like the & function for this

Assuming that you are using cells A1 and A2 for John Smith

=left(a1,1) & b1

If you want to add text between, for example a period

=left(a1,1) & "." & b1

Error handling with try and catch in Laravel

You are inside a namespace so you should use \Exception to specify the global namespace:

try {

  $this->buildXMLHeader();

} catch (\Exception $e) {

    return $e->getMessage();
}

In your code you've used catch (Exception $e) so Exception is being searched in/as:

App\Services\PayUService\Exception

Since there is no Exception class inside App\Services\PayUService so it's not being triggered. Alternatively, you can use a use statement at the top of your class like use Exception; and then you can use catch (Exception $e).

Laravel: getting a a single value from a MySQL query

yet another edit: As of version 5.2 pluck is not deprecated anymore, it just got new behaviour (same as lists previously - see side-note below):

edit: As of version 5.1 pluck is deprecated, so start using value instead:

DB::table('users')->where('username', $username)->value('groupName');    

// valid for L4 / L5.0 only
DB::table('users')->where('username', $username)->pluck('groupName');

this will return single value of groupName field of the first row found.


SIDE NOTE reg. @TomasButeler comment: As Laravel doesn't follow sensible versioning, there are sometimes cases like this. At the time of writing this answer we had pluck method to get SINGLE value from the query (Laravel 4.* & 5.0).

Then, with L5.1 pluck got deprecated and, instead, we got value method to replace it.

But to make it funny, pluck in fact was never gone. Instead it just got completely new behaviour and... deprecated lists method.. (L5.2) - that was caused by the inconsistency between Query Builder and Collection methods (in 5.1 pluck worked differently on the collection and query, that's the reason).

How to get value in the session in jQuery

Sessions are stored on the server and are set from server side code, not client side code such as JavaScript.

What you want is a cookie, someone's given a brilliant explanation in this Stack Overflow question here: How do I set/unset cookie with jQuery?

You could potentially use sessions and set/retrieve them with jQuery and AJAX, but it's complete overkill if Cookies will do the trick.

Error in if/while (condition) {: missing Value where TRUE/FALSE needed

The evaluation of condition resulted in an NA. The if conditional must have either a TRUE or FALSE result.

if (NA) {}
## Error in if (NA) { : missing value where TRUE/FALSE needed

This can happen accidentally as the results of calculations:

if(TRUE && sqrt(-1)) {}
## Error in if (TRUE && sqrt(-1)) { : missing value where TRUE/FALSE needed

To test whether an object is missing use is.na(x) rather than x == NA.


See also the related errors:

Error in if/while (condition) { : argument is of length zero

Error in if/while (condition) : argument is not interpretable as logical

if (NULL) {}
## Error in if (NULL) { : argument is of length zero

if ("not logical") {}
## Error: argument is not interpretable as logical

if (c(TRUE, FALSE)) {}
## Warning message:
## the condition has length > 1 and only the first element will be used

Optional args in MATLAB functions

A good way of going about this is not to use nargin, but to check whether the variables have been set using exist('opt', 'var').

Example:

function [a] = train(x, y, opt)
    if (~exist('opt', 'var'))
        opt = true;
    end
end

See this answer for pros of doing it this way: How to check whether an argument is supplied in function call?

INNER JOIN in UPDATE sql for DB2

You don't say what platform you're targeting. Referring to tables as files, though, leads me to believe that you're NOT running DB2 on Linux, UNIX or Windows (LUW).

However, if you are on DB2 LUW, see the MERGE statement:

For your example statement, this would be written as:

merge into file1 a
   using (select anotherfield, something from file2) b
   on substr(a.firstfield,10,20) = substr(b.anotherfield,1,10)
when matched and a.firstfield like 'BLAH%'
   then update set a.firstfield = 'BIT OF TEXT' || b.something;

Please note: For DB2, the third argument of the SUBSTR function is the number of bytes to return, not the ending position. Therefore, SUBSTR(a.firstfield,10,20) returns CHAR(20). However, SUBSTR(b.anotherfield,1,10) returns CHAR(10). I'm not sure if this was done on purpose, but it may affect your comparison.

How do I remove a comma off the end of a string?

If you're concatenating something in the loop, you can do it in this way too:

$coma = "";
foreach($a as $b){
    $string .= $coma.$b;
    $coma = ",";
}

SQL Server: Make all UPPER case to Proper Case/Title Case

Is it too late to go back and get the un-uppercased data?

The von Neumann's, McCain's, DeGuzman's, and the Johnson-Smith's of your client base may not like the result of your processing...

Also, I'm guessing that this is intended to be a one-time upgrade of the data? It might be easier to export, filter/modify, and re-import the corrected names into the db, and then you can use non-SQL approaches to name fixing...

How to ensure a <select> form field is submitted when it is disabled?

<select disabled="disabled">
    ....
</select>
<input type="hidden" name="select_name" value="selected value" />

Where select_name is the name that you would normally give the <select>.

Another option.

<select name="myselect" disabled="disabled">
    <option value="myselectedvalue" selected="selected">My Value</option>
    ....
</select>
<input type="hidden" name="myselect" value="myselectedvalue" />

Now with this one, I have noticed that depending on what webserver you are using, you may have to put the hidden input either before, or after the <select>.

If my memory serves me correctly, with IIS, you put it before, with Apache you put it after. As always, testing is key.

How to align an input tag to the center without specifying the width?

you can put in a table cell and then align the cell content.

<table>
   <tr>
     <td align="center">
        <input type="button" value="Some Button">
     </td>
   </tr>
</table>

What is fastest children() or find() in jQuery?

None of the other answers dealt with the case of using .children() or .find(">") to only search for immediate children of a parent element. So, I created a jsPerf test to find out, using three different ways to distinguish children.

As it happens, even when using the extra ">" selector, .find() is still a lot faster than .children(); on my system, 10x so.

So, from my perspective, there does not appear to be much reason to use the filtering mechanism of .children() at all.

Remove and Replace Printed items

import sys
import time

a = 0  
for x in range (0,3):  
    a = a + 1  
    b = ("Loading" + "." * a)
    # \r prints a carriage return first, so `b` is printed on top of the previous line.
    sys.stdout.write('\r'+b)
    time.sleep(0.5)
print (a)

Note that you might have to run sys.stdout.flush() right after sys.stdout.write('\r'+b) depending on which console you are doing the printing to have the results printed when requested without any buffering.

Java POI : How to read Excel cell value and not the formula computing it?

Previously posted solutions did not work for me. cell.getRawValue() returned the same formula as stated in the cell. The following function worked for me:

public void readFormula() throws IOException {
    FileInputStream fis = new FileInputStream("Path of your file");
    Workbook wb = new XSSFWorkbook(fis);
    Sheet sheet = wb.getSheetAt(0);
    FormulaEvaluator evaluator = wb.getCreationHelper().createFormulaEvaluator();

    CellReference cellReference = new CellReference("C2"); // pass the cell which contains the formula
    Row row = sheet.getRow(cellReference.getRow());
    Cell cell = row.getCell(cellReference.getCol());

    CellValue cellValue = evaluator.evaluate(cell);

    switch (cellValue.getCellType()) {
        case Cell.CELL_TYPE_BOOLEAN:
            System.out.println(cellValue.getBooleanValue());
            break;
        case Cell.CELL_TYPE_NUMERIC:
            System.out.println(cellValue.getNumberValue());
            break;
        case Cell.CELL_TYPE_STRING:
            System.out.println(cellValue.getStringValue());
            break;
        case Cell.CELL_TYPE_BLANK:
            break;
        case Cell.CELL_TYPE_ERROR:
            break;

        // CELL_TYPE_FORMULA will never happen
        case Cell.CELL_TYPE_FORMULA:
            break;
    }

}

Check if a number is int or float

It's easier to ask forgiveness than ask permission. Simply perform the operation. If it works, the object was of an acceptable, suitable, proper type. If the operation doesn't work, the object was not of a suitable type. Knowing the type rarely helps.

Simply attempt the operation and see if it works.

inNumber = somenumber
try:
    inNumberint = int(inNumber)
    print "this number is an int"
except ValueError:
    pass
try:
    inNumberfloat = float(inNumber)
    print "this number is a float"
except ValueError:
    pass

Trim spaces from start and end of string

Here is some methods I've been used in the past to trim strings in js:

String.prototype.ltrim = function( chars ) {
    chars = chars || "\\s*";
    return this.replace( new RegExp("^[" + chars + "]+", "g"), "" );
}

String.prototype.rtrim = function( chars ) {
    chars = chars || "\\s*";
    return this.replace( new RegExp("[" + chars + "]+$", "g"), "" );
}
String.prototype.trim = function( chars ) {
    return this.rtrim(chars).ltrim(chars);
}

sql delete statement where date is greater than 30 days

We can use this:

    DELETE FROM table_name WHERE date_column < 
           CAST(CONVERT(char(8), (DATEADD(day,-30,GETDATE())), 112) AS datetime)

But a better option is to use:

DELETE FROM table_name WHERE DATEDIFF(dd, date_column, GETDATE()) > 30

The former is not sargable (i.e. functions on the right side of the expression so it can’t use index) and takes 30 seconds, the latter is sargable and takes less than a second.

How can I make a link from a <td> table cell

You can creat the table you want, save it as an image and then use an image map to creat the link (this way you can put the coords of the hole td to make it in to a link).

Run exe file with parameters in a batch file

This should work:

start "" "c:\program files\php\php.exe" D:\mydocs\mp\index.php param1 param2

The start command interprets the first argument as a window title if it contains spaces. In this case, that means start considers your whole argument a title and sees no command. Passing "" (an empty title) as the first argument to start fixes the problem.

Regex for remove everything after | (with | )

If you want to get everything after | excluding set character use this code.

[^|]*$

Others solutions \|.*$

Results : | mypcworld

This one [^|]*$

Results : mypcworld

http://regexr.com/3elkd

git am error: "patch does not apply"

I had this error, was able to overcome it by using : patch -p1 < example.patch

I took it from here: https://www.drupal.org/node/1129120

How to remove an element slowly with jQuery?

I'm little late to the party, but for anyone like me that came from a Google search and didn't find the right answer. Don't get me wrong there are good answers here, but not exactly what I was looking for, without further ado, here is what I did:

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$(document).ready(function() {
    
    var $deleteButton = $('.deleteItem');

    $deleteButton.on('click', function(event) {
      event.preventDefault();

      var $button = $(this);

      if(confirm('Are you sure about this ?')) {

        var $item = $button.closest('tr.item');

        $item.addClass('removed-item')
        
            .one('webkitAnimationEnd oanimationend msAnimationEnd animationend', function(e) {
          
                $(this).remove();
        });
      }
      
    });
    
});
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/**
 * Credit to Sara Soueidan
 * @link https://github.com/SaraSoueidan/creative-list-effects/blob/master/css/styles-4.css
 */

.removed-item {
    -webkit-animation: removed-item-animation .6s cubic-bezier(.55,-0.04,.91,.94) forwards;
    -o-animation: removed-item-animation .6s cubic-bezier(.55,-0.04,.91,.94) forwards;
    animation: removed-item-animation .6s cubic-bezier(.55,-0.04,.91,.94) forwards
}

@keyframes removed-item-animation {
    from {
        opacity: 1;
        -webkit-transform: scale(1);
        -ms-transform: scale(1);
        -o-transform: scale(1);
        transform: scale(1)
    }

    to {
        -webkit-transform: scale(0);
        -ms-transform: scale(0);
        -o-transform: scale(0);
        transform: scale(0);
        opacity: 0
    }
}

@-webkit-keyframes removed-item-animation {
    from {
        opacity: 1;
        -webkit-transform: scale(1);
        transform: scale(1)
    }

    to {
        -webkit-transform: scale(0);
        transform: scale(0);
        opacity: 0
    }
}

@-o-keyframes removed-item-animation {
    from {
        opacity: 1;
        -o-transform: scale(1);
        transform: scale(1)
    }

    to {
        -o-transform: scale(0);
        transform: scale(0);
        opacity: 0
    }
}
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<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
  <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"/>
</head>
<body>
  
  <table class="table table-striped table-bordered table-hover">
    <thead>
      <tr>
        <th>id</th>
        <th>firstname</th>
        <th>lastname</th>
        <th>@twitter</th>
        <th>action</th>
      </tr>
    </thead>
    <tbody>
      
      <tr class="item">
        <td>1</td>
        <td>Nour-Eddine</td>
        <td>ECH-CHEBABY</td>
        <th>@__chebaby</th>
        <td><button class="btn btn-danger deleteItem">Delete</button></td>
      </tr>
      
      <tr class="item">
        <td>2</td>
        <td>John</td>
        <td>Doe</td>
        <th>@johndoe</th>
        <td><button class="btn btn-danger deleteItem">Delete</button></td>
      </tr>
      
      <tr class="item">
        <td>3</td>
        <td>Jane</td>
        <td>Doe</td>
        <th>@janedoe</th>
        <td><button class="btn btn-danger deleteItem">Delete</button></td>
      </tr>
    </tbody>
  </table>
  
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>


</body>
</html>
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_x000D_
_x000D_

Why does the order in which libraries are linked sometimes cause errors in GCC?

I have seen this a lot, some of our modules link in excess of a 100 libraries of our code plus system & 3rd party libs.

Depending on different linkers HP/Intel/GCC/SUN/SGI/IBM/etc you can get unresolved functions/variables etc, on some platforms you have to list libraries twice.

For the most part we use structured hierarchy of libraries, core, platform, different layers of abstraction, but for some systems you still have to play with the order in the link command.

Once you hit upon a solution document it so the next developer does not have to work it out again.

My old lecturer used to say, "high cohesion & low coupling", it’s still true today.

android: how to use getApplication and getApplicationContext from non activity / service class

In order to avoid to pass this argument i use class derived from Application

public class MyApplication extends Application {

private static Context sContext;

@Override
public void onCreate() {
    super.onCreate();
    sContext=   getApplicationContext();

}

public static Context getContext() {
    return sContext;
}

and invoke MyApplication.getContext() in Helper classes.

Don't forget to update the manifest.

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.example"> 
      <application 
       android:name=".MyApplication"
       android:allowBackup="true" 
       android:icon="@mipmap/ic_launcher" 
       android:label="@string/app_name"> 
         <activity....>
            ......
         </activity>
     </application> 
</manifest>

Uncaught syntaxerror: unexpected identifier?

There are errors here :

var formTag = document.getElementsByTagName("form"), // form tag is an array
selectListItem = $('select'),
makeSelect = document.createElement('select'),
makeSelect.setAttribute("id", "groups");

The code must change to:

var formTag = document.getElementsByTagName("form");
var selectListItem = $('select');
var makeSelect = document.createElement('select');
makeSelect.setAttribute("id", "groups");

By the way, there is another error at line 129 :

var createLi.appendChild(createSubList);

Replace it with:

createLi.appendChild(createSubList);

SQLSTATE[28000] [1045] Access denied for user 'root'@'localhost' (using password: YES) Symfony2

Ok, so this might not fix your issue but it definitely worked for me.

So you've created your Mysql user I take it? Go to user privileges on PhpMyAdmin and click edit next to the user your using for Symfony. Scroll down to near the bottom and where it says which host you want to use make sure you've selected LocalHost not % Any.

Then in your config file swap 127.0.0.1 for localhost. Hopefully that will work for you. Just worked for me as I was having the same issue.

MassAssignmentException in Laravel

I am using Laravel 4.2.

the error you are seeing

[Illuminate\Database\Eloquent\MassAssignmentException]
username

indeed is because the database is protected from filling en masse, which is what you are doing when you are executing a seeder. However, in my opinion, it's not necessary (and might be insecure) to declare which fields should be fillable in your model if you only need to execute a seeder.

In your seeding folder you have the DatabaseSeeder class:

class DatabaseSeeder extends Seeder {

    /**
    * Run the database seeds.
    *
    * @return void
    */

    public function run()
    {
        Eloquent::unguard();

        //$this->call('UserTableSeeder');
    }
}

This class acts as a facade, listing all the seeders that need to be executed. If you call the UsersTableSeeder seeder manually through artisan, like you did with the php artisan db:seed --class="UsersTableSeeder" command, you bypass this DatabaseSeeder class.

In this DatabaseSeeder class the command Eloquent::unguard(); allows temporary mass assignment on all tables, which is exactly what you need when you are seeding a database. This unguard method is only executed when you run the php aristan db:seed command, hence it being temporary as opposed to making the fields fillable in your model (as stated in the accepted and other answers).

All you need to do is add the $this->call('UsersTableSeeder'); to the run method in the DatabaseSeeder class and run php aristan db:seed in your CLI which by default will execute DatabaseSeeder.

Also note that you are using a plural classname Users, while Laraval uses the the singular form User. If you decide to change your class to the conventional singular form, you can simply uncomment the //$this->call('UserTableSeeder'); which has already been assigned but commented out by default in the DatabaseSeeder class.

Printing image with PrintDocument. how to adjust the image to fit paper size

The solution provided by BBoy works fine. But in my case I had to use

e.Graphics.DrawImage(memoryImage, e.PageBounds);

This will print only the form. When I use MarginBounds it prints the entire screen even if the form is smaller than the monitor screen. PageBounds solved that issue. Thanks to BBoy!

Qt c++ aggregate 'std::stringstream ss' has incomplete type and cannot be defined

You probably have a forward declaration of the class, but haven't included the header:

#include <sstream>

//...
QString Stats_Manager::convertInt(int num)
{
    std::stringstream ss;   // <-- also note namespace qualification
    ss << num;
    return ss.str();
}

How can I clear event subscriptions in C#?

class c1
{
    event EventHandler someEvent;
    ResetSubscriptions() => someEvent = delegate { };
}

It is better to use delegate { } than null to avoid the null ref exception.

Fake "click" to activate an onclick method

This is a perfect example of where you should use a javascript library like Prototype or JQuery to abstract away the cross-browser differences.

How to get the row number from a datatable?

You do know that DataRow is the row of a DataTable correct?

What you currently have already loop through each row. You just have to keep track of how many rows there are in order to get the current row.

int i = 0;
int index = 0;
foreach (DataRow row in dt.Rows) 
{
index = i;
// do stuff
i++;
} 

Saving images in Python at a very high quality

In case you are working with seaborn plots, instead of Matplotlib, you can save a .png image like this:

Let's suppose you have a matrix object (either Pandas or NumPy), and you want to take a heatmap:

import seaborn as sb

image = sb.heatmap(matrix)   # This gets you the heatmap
image.figure.savefig("C:/Your/Path/ ... /your_image.png")   # This saves it

This code is compatible with the latest version of Seaborn. Other code around Stack Overflow worked only for previous versions.

Another way I like is this. I set the size of the next image as follows:

plt.subplots(figsize=(15,15))

And then later I plot the output in the console, from which I can copy-paste it where I want. (Since Seaborn is built on top of Matplotlib, there will not be any problem.)

Apache giving 403 forbidden errors

The server may need read permission for your home directory and .htaccess therein

How to use new PasswordEncoder from Spring Security

I had a similar issue. I needed to keep the legacy encrypted passwords (Base64/SHA-1/Random salt Encoded) as users will not want to change their passwords or re-register. However I wanted to use the BCrypt encoder moving forward too.

My solution was to write a bespoke decoder that checks to see which encryption method was used first before matching (BCrypted ones start with $).

To get around the salt issue, I pass into the decoder a concatenated String of salt + encrypted password via my modified user object.

Decoder

@Component
public class LegacyEncoder implements PasswordEncoder {

    private static final String BCRYP_TYPE = "$";
    private static final PasswordEncoder BCRYPT = new BCryptPasswordEncoder();

    @Override
    public String encode(CharSequence rawPassword) {

    return BCRYPT.encode(rawPassword);
    }

    @Override
    public boolean matches(CharSequence rawPassword, String encodedPassword) {

    if (encodedPassword.startsWith(BCRYP_TYPE)) {
        return BCRYPT.matches(rawPassword, encodedPassword);
    }

    return sha1SaltMatch(rawPassword, encodedPassword);
    }

    @SneakyThrows
    private boolean sha1SaltMatch(CharSequence rawPassword, String encodedPassword) {

    String[] saltHash = encodedPassword.split(User.SPLIT_CHAR);

    // Legacy code from old system   
    byte[] b64salt = Base64.getDecoder().decode(saltHash[0].getBytes());
    byte[] validHash = Base64.getDecoder().decode(saltHash[1]);
    byte[] checkHash = Utility.getHash(5, rawPassword.toString(), b64salt);

    return Arrays.equals(checkHash, validHash);
    }

}

User Object

public class User implements UserDetails {

    public static final String SPLIT_CHAR = ":";

    @Id
    @Column(name = "user_id", nullable = false)
    private Integer userId;

    @Column(nullable = false, length = 60)
    private String password;

    @Column(nullable = true, length = 32)
    private String salt;

.
.

    @PostLoad
    private void init() {

    username = emailAddress; //To comply with UserDetails
    password = salt == null ? password : salt + SPLIT_CHAR + password;
    }        

You can also add a hook to re-encode the password in the new BCrypt format and replace it. Thus phasing out the old method.

What do 3 dots next to a parameter type mean in Java?

This is the Java way to pass varargs (variable number arguments).

If you are familiar with C, this is similar to the ... syntax used it the printf function:

int printf(const char * format, ...);

but in a type safe fashion: every argument has to comply with the specified type (in your sample, they should be all String).

This is a simple sample of how you can use varargs:

class VarargSample {

   public static void PrintMultipleStrings(String... strings) {
      for( String s : strings ) {
          System.out.println(s);
      }
   }

   public static void main(String[] args) {
      PrintMultipleStrings("Hello", "world");
   }
}

The ... argument is actually an array, so you could pass a String[] as the parameter.

How to change language settings in R

You may also want to be aware of the difference between, for example, Sys.setenv(LANG = "ru") and Sys.setlocale(locale = "ru_RU.utf8").

> Sys.setlocale(locale = "ru_RU.utf8")
[1] "LC_CTYPE=ru_RU.utf8;LC_NUMERIC=C;LC_TIME=ru_RU.utf8;LC_COLLATE=ru_RU.utf8;LC_MONETARY=ru_RU.utf8;LC_MESSAGES=en_IE.utf8;LC_PAPER=en_IE.utf8;LC_NAME=en_IE.utf8;LC_ADDRESS=en_IE.utf8;LC_TELEPHONE=en_IE.utf8;LC_MEASUREMENT=en_IE.utf8;LC_IDENTIFICATION=en_IE.utf8"

If you are interested in changing the behaviour of functions that refer to one of these elements (e.g strptime to extract dates), you should use Sys.setlocale(). See ?Sys.setlocale for more details. In order to see all available languages on a linux system, you can run

system("locale -a", intern = TRUE)

Error converting data types when importing from Excel to SQL Server 2008

SSIS doesn't implicitly convert data types, so you need to do it explicitly. The Excel connection manager can only handle a few data types and it tries to make a best guess based on the first few rows of the file. This is fully documented in the SSIS documentation.

You have several options:

  • Change your destination data type to float
  • Load to a 'staging' table with data type float using the Import Wizard and then INSERT into the real destination table using CAST or CONVERT to convert the data
  • Create an SSIS package and use the Data Conversion transformation to convert the data

You might also want to note the comments in the Import Wizard documentation about data type mappings.

Get path from open file in Python

I had the exact same issue. If you are using a relative path os.path.dirname(path) will only return the relative path. os.path.realpath does the trick:

>>> import os
>>> f = open('file.txt')
>>> os.path.realpath(f.name)

How do I find the location of my Python site-packages directory?

This should work on all distributions in and out of virtual environment due to it's "low-tech" nature. The os module always resides in the parent directory of 'site-packages'

import os; print(os.path.dirname(os.__file__) + '/site-packages')

To change dir to the site-packages dir I use the following alias (on *nix systems):

alias cdsp='cd $(python -c "import os; print(os.path.dirname(os.__file__))"); cd site-packages'

How to mention C:\Program Files in batchfile

Now that bash is out for windows 10, if you want to access program files from bash, you can do it like so: cd /mnt/c/Program\ Files.

difference between $query>num_rows() and $this->db->count_all_results() in CodeIgniter & which one is recommended

$this->db->count_all_results is part of an Active Record query (preparing the query, to only return the number, not the actual results).

$query->num_rows() is performed on a resultset object (after returning results from the DB).

Error "There is already an open DataReader associated with this Command which must be closed first" when using 2 distinct commands

Add MultipleActiveResultSets=true to the provider part of your connection string. See the example below:

<add name="DbContext" connectionString="Data Source=(LocalDb)\v11.0;Initial Catalog=dbName;Persist Security Info=True;User ID=userName;Password=password;MultipleActiveResultSets=True" providerName="System.Data.SqlClient" />

Responsive web design is working on desktop but not on mobile device

Responsive meta tag

To ensure proper rendering and touch zooming for all devices, add the responsive viewport meta tag to your <head>.

<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

Is there a way to automatically generate getters and setters in Eclipse?

There is an open source jar available know as Lombok , you just add jar and then annotate your POJO with @Getter & @Setter it will create getters and setters automatically.

Apart from this we can use other features like @ToString ,@EqualsAndHashCode and pretty other cool stuff which removes vanilla code from your application

Hibernate - Batch update returned unexpected row count from update: 0 actual row count: 0 expected: 1

i got the same problem and i verified this may occur because of Auto increment primary key. To solve this problem do not inset auto increment value with data set. Insert data without the primary key.

Check with jquery if div has overflowing elements

I fixed this by adding another div in the one that overflows. Then you compare the heights of the 2 divs.

<div class="AAAA overflow-hidden" style="height: 20px;" >
    <div class="BBBB" >
        Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
    </div>
</div>

and the js

    if ($('.AAAA').height() < $('.BBBB').height()) {
        console.log('we have overflow')
    } else {
        console.log('NO overflow')
    }

This looks easier...

How to make `setInterval` behave more in sync, or how to use `setTimeout` instead?

As someone else pointed out, the Web Audio API has a better timer.

But in general, if these events happen consistently, how about you put them all on the same timer? I'm thinking about how a step sequencer works.

Practically, could it looks something like this?

var timer = 0;
var limit = 8000; // 8000 will be the point at which the loop repeats

var drumInterval = 8000;
var chordInterval = 1000;
var bassInterval = 500;

setInterval(function {
    timer += 500;

    if (timer == drumInterval) {
        // Do drum stuff
    }

    if (timer == chordInterval) {
        // Do chord stuff
    }

    if (timer == bassInterval) {
        // Do bass stuff
    }

    // Reset timer once it reaches limit
    if (timer == limit) {
        timer = 0;
    }

}, 500); // Set the timer to the smallest common denominator

MySQL Where DateTime is greater than today

SELECT * 
FROM customer 
WHERE joiningdate >= NOW();

What is the Maximum Size that an Array can hold?

Per MSDN it is

By default, the maximum size of an Array is 2 gigabytes (GB).

In a 64-bit environment, you can avoid the size restriction by setting the enabled attribute of the gcAllowVeryLargeObjects configuration element to true in the run-time environment.

However, the array will still be limited to a total of 4 billion elements.

Refer Here http://msdn.microsoft.com/en-us/library/System.Array(v=vs.110).aspx

Note: Here I am focusing on the actual length of array by assuming that we will have enough hardware RAM.

How to clear the entire array?

Only use Redim statement

 Dim aFirstArray() As Variant

Redim aFirstArray(nRows,nColumns)

Download file from an ASP.NET Web API method using AngularJS

You could implement a showfile function which takes in parameters of the data returned from the WEBApi, and a filename for the file you are trying to download. What I did was create a separate browser service identifies the user's browser and then handles the rendering of the file based on the browser. For instance if the target browser is chrome on an ipad, you have to use javascripts FileReader object.

FileService.showFile = function (data, fileName) {
    var blob = new Blob([data], { type: 'application/pdf' });

    if (BrowserService.isIE()) {
        window.navigator.msSaveOrOpenBlob(blob, fileName);
    }
    else if (BrowserService.isChromeIos()) {
        loadFileBlobFileReader(window, blob, fileName);
    }
    else if (BrowserService.isIOS() || BrowserService.isAndroid()) {
        var url = URL.createObjectURL(blob);
        window.location.href = url;
        window.document.title = fileName;
    } else {
        var url = URL.createObjectURL(blob);
        loadReportBrowser(url, window,fileName);
    }
}


function loadFileBrowser(url, window, fileName) {
    var iframe = window.document.createElement('iframe');
    iframe.src = url
    iframe.width = '100%';
    iframe.height = '100%';
    iframe.style.border = 'none';
    window.document.title = fileName;
    window.document.body.appendChild(iframe)
    window.document.body.style.margin = 0;
}

function loadFileBlobFileReader(window, blob,fileName) {
    var reader = new FileReader();
    reader.onload = function (e) {
        var bdata = btoa(reader.result);
        var datauri = 'data:application/pdf;base64,' + bdata;
        window.location.href = datauri;
        window.document.title = fileName;
    }
    reader.readAsBinaryString(blob);
}

How can one check to see if a remote file exists using PHP?

PHP's inbuilt functions may not work for checking URL if allow_url_fopen setting is set to off for security reasons. Curl is a better option as we would not need to change our code at later stage. Below is the code I used to verify a valid URL:

$url = str_replace(' ', '%20', $url);
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); 
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_exec($ch);
$httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);  
curl_close($ch);
if($httpcode>=200 && $httpcode<300){  return true; } else { return false; } 

Kindly note the CURLOPT_SSL_VERIFYPEER option which also verify the URL's starting with HTTPS.

When creating a service with sc.exe how to pass in context parameters?

it is not working in the Powershell and should use CMD in my case

Fire event on enter key press for a textbox

My 2c.. I have used javascript, but found it did things that were not quite expected.

USE the panel's defaultButton attribute/property as many of the above posts suggest. It is reliable (EASY) and works in all the browsers I have tested it on.

How to vertically center a <span> inside a div?

At your parent DIV add

display:table;

and at your child element add

 display:table-cell;
 vertical-align:middle;

Send value of submit button when form gets posted

The initial post mentioned buttons. You can also replace the input tags with buttons.

<button type="submit" name="product" value="Tea">Tea</button>
<button type="submit" name="product" value="Coffee">Coffee</button>

The name and value attributes are required to submit the value when the form is submitted (the id attribute is not necessary in this case). The attribute type=submit specifies that clicking on this button causes the form to be submitted.

When the server is handling the submitted form, $_POST['product'] will contain the value "Tea" or "Coffee" depending on which button was clicked.

If you want you can also require the user to confirm before submitting the form (useful when you are implementing a delete button for example).

<button type="submit" name="product" value="Tea" onclick="return confirm('Are you sure you want tea?');">Tea</button>
<button type="submit" name="product" value="Coffee" onclick="return confirm('Are you sure you want coffee?');">Coffee</button>

Android: Clear the back stack

Use this code for starting a new Activity and close or destroy all other activity stack or back stack.

Intent intent = new Intent(this, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

How to show the "Are you sure you want to navigate away from this page?" when changes committed?

There is an "onunload" parameter for the body tag you can call javascript functions from there. If it returns false it prevents navigating away.

What is the difference between explicit and implicit cursors in Oracle?

From a performance point of view, Implicit cursors are faster.

Let's compare the performance between an explicit and implicit cursor:

SQL> DECLARE
  2    l_loops  NUMBER := 100000;
  3    l_dummy  dual.dummy%TYPE;
  4    l_start  NUMBER;
  5    -- explicit cursor declaration
  6    CURSOR c_dual IS
  7      SELECT dummy
  8      FROM   dual;
  9  BEGIN
 10    l_start := DBMS_UTILITY.get_time;
 11    -- explicitly open, fetch and close the cursor
 12    FOR i IN 1 .. l_loops LOOP
 13      OPEN  c_dual;
 14      FETCH c_dual
 15      INTO  l_dummy;
 16      CLOSE c_dual;
 17    END LOOP;
 18
 19    DBMS_OUTPUT.put_line('Explicit: ' ||
 20                         (DBMS_UTILITY.get_time - l_start) || ' hsecs');
 21
 22    l_start := DBMS_UTILITY.get_time;
 23    -- implicit cursor for loop
 24    FOR i IN 1 .. l_loops LOOP
 25      SELECT dummy
 26      INTO   l_dummy
 27      FROM   dual;
 28    END LOOP;
 29
 30    DBMS_OUTPUT.put_line('Implicit: ' ||
 31                         (DBMS_UTILITY.get_time - l_start) || ' hsecs');
 32  END;
 33  /
Explicit: 332 hsecs
Implicit: 176 hsecs

PL/SQL procedure successfully completed.

So, a significant difference is clearly visible. Implicit cursor is much faster than an explicit cursor.

More examples here.

how to set the background color of the whole page in css

The problem is that the body of the page isn't actually visible. The DIVs under have width of 100% and have background colors themselves that override the body CSS.

To Fix the no-man's land, this might work. It's not elegant, but works.

#doc3 {
    margin: auto 10px;
    width: auto;
    height: 2000px;
    background-color: yellow;
}

Get only part of an Array in Java?

public static int[] range(int[] array, int start, int end){
        int returner[] = new int[end-start];
        for(int x = 0; x <= end-start-1; x++){
            returner[x] = array[x+start];
        }
        return returner;
    }

this is a way to do the same thing as Array.copyOfRange but without importing anything

Implement a loading indicator for a jQuery AJAX call

This is how I realised the loading indicator by an Glyphicon:

<!DOCTYPE html>
<html>

<head>
    <title>Demo</title>

    <link rel="stylesheet" href="https://ajax.aspnetcdn.com/ajax/bootstrap/3.3.6/css/bootstrap.min.css">
    <script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.12.4.min.js"></script>
    <script src="https://ajax.aspnetcdn.com/ajax/bootstrap/3.3.6/bootstrap.min.js"></script>

    <style>
        .gly-ani {
          animation: ani 2s infinite linear;
        }
        @keyframes ani {
          0% {
            transform: rotate(0deg);
          }
          100% {
            transform: rotate(359deg);
          }
        }
    </style>  
</head>

<body>
<div class="container">

    <span class="glyphicon glyphicon-refresh gly-ani" style="font-size:40px;"></span>

</div>
</body>

</html>

jQuery/Javascript function to clear all the fields of a form

Note: this answer is relevant to resetting form fields, not clearing fields - see update.

You can use JavaScript's native reset() method to reset the entire form to its default state.

Example provided by Ryan:

$('#myForm')[0].reset();

Note: This may not reset certain fields, such as type="hidden".

UPDATE

As noted by IlyaDoroshin the same thing can be accomplished using jQuery's trigger():

$('#myForm').trigger("reset");

UPDATE

If you need to do more than reset the form to its default state, you should review the answers to Resetting a multi-stage form with jQuery.

loading json data from local file into React JS

If you have couple of json files:

import data from 'sample.json';

If you were to dynamically load one of the many json file, you might have to use a fetch instead:

fetch(`${fileName}.json`)
  .then(response => response.json())
  .then(data => console.log(data))

How to enable scrolling on website that disabled scrolling?

Select the Body using chrome dev tools (Inspect ) and change in css overflow:visible,

If that doesn't work then check in below css file if html, body is set as overflow:hidden , change it as visible

How do I use cascade delete with SQL Server?

I think you cannot just delete the tables property what if this is actual production data, just delete the contents that dont affect the table schema.

What does 'Unsupported major.minor version 52.0' mean, and how do I fix it?

Actually you have a code compiled targeting a higher JDK (JDK 1.8 in your case) but at runtime you are supplying a lower JRE(JRE 7 or below).

you can fix this problem by adding target parameter while compilation
e.g. if your runtime target is 1.7, you should use 1.7 or below

javac -target 1.7 *.java

if you are using eclipse, you can sent this parameter at Window -> Preferences -> Java -> Compiler -> set "Compiler compliance level" = choose your runtime jre version or lower.

HTML5 Video tag not working in Safari , iPhone and iPad

What helped in my case was dropping the audio track. It was silent before, but it had to be gone completely.

On ubuntu:

ffmpeg -i input.mp4 -vcodec copy -an output.mp4

And safari/desktop start to play the video

The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead

  1. Why is this happening?

    The entire ext/mysql PHP extension, which provides all functions named with the prefix mysql_, was officially deprecated in PHP v5.5.0 and removed in PHP v7.

    It was originally introduced in PHP v2.0 (November 1997) for MySQL v3.20, and no new features have been added since 2006. Coupled with the lack of new features are difficulties in maintaining such old code amidst complex security vulnerabilities.

    The manual has contained warnings against its use in new code since June 2011.

  2. How can I fix it?

    As the error message suggests, there are two other MySQL extensions that you can consider: MySQLi and PDO_MySQL, either of which can be used instead of ext/mysql. Both have been in PHP core since v5.0, so if you're using a version that is throwing these deprecation errors then you can almost certainly just start using them right away—i.e. without any installation effort.

    They differ slightly, but offer a number of advantages over the old extension including API support for transactions, stored procedures and prepared statements (thereby providing the best way to defeat SQL injection attacks). PHP developer Ulf Wendel has written a thorough comparison of the features.

    Hashphp.org has an excellent tutorial on migrating from ext/mysql to PDO.

  3. I understand that it's possible to suppress deprecation errors by setting error_reporting in php.ini to exclude E_DEPRECATED:

    error_reporting = E_ALL ^ E_DEPRECATED
    

    What will happen if I do that?

    Yes, it is possible to suppress such error messages and continue using the old ext/mysql extension for the time being. But you really shouldn't do this—this is a final warning from the developers that the extension may not be bundled with future versions of PHP (indeed, as already mentioned, it has been removed from PHP v7). Instead, you should take this opportunity to migrate your application now, before it's too late.

    Note also that this technique will suppress all E_DEPRECATED messages, not just those to do with the ext/mysql extension: therefore you may be unaware of other upcoming changes to PHP that would affect your application code. It is, of course, possible to only suppress errors that arise on the expression at issue by using PHP's error control operator—i.e. prepending the relevant line with @—however this will suppress all errors raised by that expression, not just E_DEPRECATED ones.


What should you do?

  • You are starting a new project.

    There is absolutely no reason to use ext/mysql—choose one of the other, more modern, extensions instead and reap the rewards of the benefits they offer.

  • You have (your own) legacy codebase that currently depends upon ext/mysql.

    It would be wise to perform regression testing: you really shouldn't be changing anything (especially upgrading PHP) until you have identified all of the potential areas of impact, planned around each of them and then thoroughly tested your solution in a staging environment.

    • Following good coding practice, your application was developed in a loosely integrated/modular fashion and the database access methods are all self-contained in one place that can easily be swapped out for one of the new extensions.

      Spend half an hour rewriting this module to use one of the other, more modern, extensions; test thoroughly. You can later introduce further refinements to reap the rewards of the benefits they offer.

    • The database access methods are scattered all over the place and cannot easily be swapped out for one of the new extensions.

      Consider whether you really need to upgrade to PHP v5.5 at this time.

      You should begin planning to replace ext/mysql with one of the other, more modern, extensions in order that you can reap the rewards of the benefits they offer; you might also use it as an opportunity to refactor your database access methods into a more modular structure.

      However, if you have an urgent need to upgrade PHP right away, you might consider suppressing deprecation errors for the time being: but first be sure to identify any other deprecation errors that are also being thrown.

  • You are using a third party project that depends upon ext/mysql.

    Consider whether you really need to upgrade to PHP v5.5 at this time.

    Check whether the developer has released any fixes, workarounds or guidance in relation to this specific issue; or, if not, pressure them to do so by bringing this matter to their attention. If you have an urgent need to upgrade PHP right away, you might consider suppressing deprecation errors for the time being: but first be sure to identify any other deprecation errors that are also being thrown.

    It is absolutely essential to perform regression testing.

Flask Download a File

You need to make sure that the value you pass to the directory argument is an absolute path, corrected for the current location of your application.

The best way to do this is to configure UPLOAD_FOLDER as a relative path (no leading slash), then make it absolute by prepending current_app.root_path:

@app.route('/uploads/<path:filename>', methods=['GET', 'POST'])
def download(filename):
    uploads = os.path.join(current_app.root_path, app.config['UPLOAD_FOLDER'])
    return send_from_directory(directory=uploads, filename=filename)

It is important to reiterate that UPLOAD_FOLDER must be relative for this to work, e.g. not start with a /.

A relative path could work but relies too much on the current working directory being set to the place where your Flask code lives. This may not always be the case.

get Context in non-Activity class

If your class is non-activity class, and creating an instance of it from the activiy, you can pass an instance of context via constructor of the later as follows:

class YourNonActivityClass{

// variable to hold context
private Context context;

//save the context recievied via constructor in a local variable

public YourNonActivityClass(Context context){
    this.context=context;
}

}

You can create instance of this class from the activity as follows:

new YourNonActivityClass(this);

How to create Windows EventLog source from command line?

you can create your own custom event by using diagnostics.Event log class. Open a windows application and on a button click do the following code.

System.Diagnostics.EventLog.CreateEventSource("ApplicationName", "MyNewLog");

"MyNewLog" means the name you want to give to your log in event viewer.

for more information check this link [ http://msdn.microsoft.com/en-in/library/49dwckkz%28v=vs.90%29.aspx]

How to add image that is on my computer to a site in css or html?

No, Not if your website is on a remote server, i.e not on localhost.

How to refer environment variable in POM.xml?

You can use <properties> tag to define a custom variable and ${variable} pattern to use it

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <!-- define -->
    <properties>
        <property.name>1.0</property.name>
    </properties>

    <!-- using -->
    <version>${property.name}</version>

</project>

Listing contents of a bucket with boto3

One way that I used to do this:

import boto3
s3 = boto3.resource('s3')
bucket=s3.Bucket("bucket_name")
contents = [_.key for _ in bucket.objects.all() if "subfolders/ifany/" in _.key]

css display table cell requires percentage width

You just need to add 'table-layout: fixed;'

.table {
   display: table;
   height: 100px;
   width: 100%;
   table-layout: fixed;
}

http://www.w3schools.com/cssref/pr_tab_table-layout.asp

URL.Action() including route values

outgoing url in mvc generated based on the current routing schema.

because your Information action method require id parameter, and your route collection has id of your current requested url(/Admin/Information/5), id parameter automatically gotten from existing route collection values.

to solve this problem you should use UrlParameter.Optional:

 <a href="@Url.Action("Information", "Admin", new { id = UrlParameter.Optional })">Add an Admin</a>

Count all occurrences of a string in lots of files with grep

If you want number of occurrences per file (example for string "tcp"):

grep -RIci "tcp" . | awk -v FS=":" -v OFS="\t" '$2>0 { print $2, $1 }' | sort -hr

Example output:

53  ./HTTPClient/src/HTTPClient.cpp
21  ./WiFi/src/WiFiSTA.cpp
19  ./WiFi/src/ETH.cpp
13  ./WiFi/src/WiFiAP.cpp
4   ./WiFi/src/WiFiClient.cpp
4   ./HTTPClient/src/HTTPClient.h
3   ./WiFi/src/WiFiGeneric.cpp
2   ./WiFi/examples/WiFiClientBasic/WiFiClientBasic.ino
2   ./WiFiClientSecure/src/ssl_client.cpp
1   ./WiFi/src/WiFiServer.cpp

Explanation:

  • grep -RIci NEEDLE . - looks for string NEEDLE recursively from current directory (following symlinks), ignoring binaries, counting number of occurrences, ignoring case
  • awk ... - this command ignores files with zero occurrences and formats lines
  • sort -hr - sorts lines in reverse order by numbers in first column

Of course, it works with other grep commands with option -c (count) as well. For example:

grep -c "tcp" *.txt | awk -v FS=":" -v OFS="\t" '$2>0 { print $2, $1 }' | sort -hr

How to create a oracle sql script spool file

In order to execute a spool file in plsql Go to File->New->command window -> paste your code-> execute. Got to the directory and u will find the file.

How to write/update data into cells of existing XLSX workbook using xlsxwriter in python

You can do by xlwings as well

import xlwings as xw
for book in xlwings.books:
    print(book)

Lightweight Javascript DB for use in Node.js

LevelUP aims to expose the features of LevelDB in a Node.js-friendly way.

https://github.com/rvagg/node-levelup

You can also look at UnQLite. with a node.js binding node-unqlite

https://github.com/symisc/unqlite

How to get object length

So one does not have to find and replace the Object.keys method, another approach would be this code early in the execution of the script:

if(!Object.keys)
{
  Object.keys = function(obj)
  {
    return $.map(obj, function(v, k)
    {
      return k;
    });
  };
 }

JSON Stringify changes time of date because of UTC

Here is something really neat and simple (atleast I believe so :)) and requires no manipulation of date to be cloned or overloading any of browser's native functions like toJSON (reference: How to JSON stringify a javascript Date and preserve timezone, courtsy Shawson)

Pass a replacer function to JSON.stringify that stringifies stuff to your heart's content!!! This way you don't have to do hour and minute diffs or any other manipulations.

I have put in console.logs to see intermediate results so it is clear what is going on and how recursion is working. That reveals something worthy of notice: value param to replacer is already converted to ISO date format :). Use this[key] to work with original data.

var replacer = function(key, value)
{
    var returnVal = value;
    if(this[key] instanceof Date)
    {
        console.log("replacer called with key - ", key, " value - ", value, this[key]); 

        returnVal = this[key].toString();

        /* Above line does not strictly speaking clone the date as in the cloned object 
         * it is a string in same format as the original but not a Date object. I tried 
         * multiple things but was unable to cause a Date object being created in the 
         * clone. 
         * Please Heeeeelp someone here!

        returnVal = new Date(JSON.parse(JSON.stringify(this[key])));   //OR
        returnVal = new Date(this[key]);   //OR
        returnVal = this[key];   //careful, returning original obj so may have potential side effect

*/
    }
    console.log("returning value: ", returnVal);

    /* if undefined is returned, the key is not at all added to the new object(i.e. clone), 
     * so return null. null !== undefined but both are falsy and can be used as such*/
    return this[key] === undefined ? null : returnVal;
};

ab = {prop1: "p1", prop2: [1, "str2", {p1: "p1inner", p2: undefined, p3: null, p4date: new Date()}]};
var abstr = JSON.stringify(ab, replacer);
var abcloned = JSON.parse(abstr);
console.log("ab is: ", ab);
console.log("abcloned is: ", abcloned);

/* abcloned is:
 * {
  "prop1": "p1",
  "prop2": [
    1,
    "str2",
    {
      "p1": "p1inner",
      "p2": null,
      "p3": null,
      "p4date": "Tue Jun 11 2019 18:47:50 GMT+0530 (India Standard Time)"
    }
  ]
}
Note p4date is string not Date object but format and timezone are completely preserved.
*/

How to connect to a MS Access file (mdb) using C#?

The simplest way to connect is through an OdbcConnection using code like this

using System.Data.Odbc;

using(OdbcConnection myConnection = new OdbcConnection())
{
    myConnection.ConnectionString = myConnectionString;
    myConnection.Open();

    //execute queries, etc

}

where myConnectionString is something like this

myConnectionString = @"Driver={Microsoft Access Driver (*.mdb)};" + 
"Dbq=C:\mydatabase.mdb;Uid=Admin;Pwd=;

See ConnectionStrings

In alternative you could create a DSN and then use that DSN in your connection string

  • Open the Control Panel - Administrative Tools - ODBC Data Source Manager
  • Go to the System DSN Page and ADD a new DSN
  • Choose the Microsoft Access Driver (*.mdb) and press END
  • Set the Name of the DSN (choose MyDSN for this example)
  • Select the Database to be used
  • Try the Compact or Recover commands to see if the connection works

now your connectionString could be written in this way

myConnectionString = "DSN=myDSN;"

Java: Detect duplicates in ArrayList?

Improved code to return the duplicate elements

  • Can find duplicates in a Collection
  • return the set of duplicates
  • Unique Elements can be obtained from the Set

public static <T> List getDuplicate(Collection<T> list) {

    final List<T> duplicatedObjects = new ArrayList<T>();
    Set<T> set = new HashSet<T>() {
    @Override
    public boolean add(T e) {
        if (contains(e)) {
            duplicatedObjects.add(e);
        }
        return super.add(e);
    }
    };
   for (T t : list) {
        set.add(t);
    }
    return duplicatedObjects;
}


public static <T> boolean hasDuplicate(Collection<T> list) {
    if (getDuplicate(list).isEmpty())
        return false;
    return true;
}

IIS 7, HttpHandler and HTTP Error 500.21

I had the same problem and was solved by running the following in run

%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i

How to get first two characters of a string in oracle query?

select substr(orderno,1,2) from shipment;

You may want to have a look at the documentation too.

What is the best way to exit a function (which has no return value) in python before the function ends (e.g. a check fails)?

I would suggest:

def foo(element):
    do something
    if not check: return
    do more (because check was succesful)
    do much much more...

How do I count occurrence of duplicate items in array

this code will return duplicate value in same array

$array = array(12,43,66,21,56,43,43,78,78,100,43,43,43,21);
foreach($arr as $key=>$item){
  if(array_count_values($arr)[$item] > 1){
     echo "Found Matched value : ".$item." <br />";
  }
}

How to decode a Base64 string?

Base64 encoding converts three 8-bit bytes (0-255) into four 6-bit bytes (0-63 aka base64). Each of the four bytes indexes an ASCII string which represents the final output as four 8-bit ASCII characters. The indexed string is typically 'A-Za-z0-9+/' with '=' used as padding. This is why encoded data is 4/3 longer.

Base64 decoding is the inverse process. And as one would expect, the decoded data is 3/4 as long.

While base64 encoding can encode plain text, its real benefit is encoding non-printable characters which may be interpreted by transmitting systems as control characters.

I suggest the original poster render $z as bytes with each bit having meaning to the application. Rendering non-printable characters as text typically invokes Unicode which produces glyphs based on your system's localization.

Base64decode("the answer to life the universe and everything") = 00101010

Eclipse/Maven error: "No compiler is provided in this environment"

Make sure you have %JAVA_HOME% set by typing echo %JAVA_HOME% in Command Prompt. If you don't have that set, then you need to go add your Java path to Window's Environmental Variables.

Make child visible outside an overflow:hidden parent

This is an old question but encountered it myself.

I have semi-solutions that work situational for the former question("Children visible in overflow:hidden parent")

If the parent div does not need to be position:relative, simply set the children styles to visibility:visible.

If the parent div does need to be position:relative, the only way possible I found to show the children was position:fixed. This worked for me in my situation luckily enough but I would imagine it wouldn't work in others.

Here is a crappy example just post into a html file to view.

<div style="background: #ff00ff; overflow: hidden; width: 500px; height: 500px; position: relative;">
    <div style="background: #ff0000;position: fixed; top: 10px; left: 10px;">asd
        <div style="background: #00ffff; width: 200px; overflow: visible; position: absolute; visibility: visible; clear:both; height: 1000px; top: 100px; left: 10px;"> a</div>
    </div>
</div>

How to import set of icons into Android Studio project

Since Android Studio 3.4, there is a new tool called Resource manager. It supports importing many drawables at once (vectors, pngs, ...) . Follow the official documentation.

How to render a DateTime in a specific format in ASP.NET MVC 3?

@{
  string datein = Convert.ToDateTime(item.InDate).ToString("dd/MM/yyyy");        
  @datein
}

How to restore the menu bar in Visual Studio Code

Another way to restore the menu bar is to trigger the View: Toggle Menu Bar command in the command palette (F1).

switch() statement usage

In short, yes. But there are times when you might favor one vs. the other. Google "case switch vs. if else". There are some discussions already on SO too. Also, here is a good video that talks about it in the context of MATLAB:

http://blogs.mathworks.com/pick/2008/01/02/matlab-basics-switch-case-vs-if-elseif/

Personally, when I have 3 or more cases, I usually just go with case/switch.

how to parse a "dd/mm/yyyy" or "dd-mm-yyyy" or "dd-mmm-yyyy" formatted date string using JavaScript or jQuery

You might want to use helper library like http://momentjs.com/ which wraps the native javascript date object for easier manipulations

Then you can do things like:

var day = moment("12-25-1995", "MM-DD-YYYY");

or

var day = moment("25/12/1995", "DD/MM/YYYY");

then operate on the date

day.add('days', 7)

and to get the native javascript date

day.toDate();

Check if an apt-get package is installed and then install it if it's not on Linux

To check if packagename was installed, type:

dpkg -s <packagename>

You can also use dpkg-query that has a neater output for your purpose, and accepts wild cards, too.

dpkg-query -l <packagename>

To find what package owns the command, try:

dpkg -S `which <command>`

For further details, see article Find out if package is installed in Linux and dpkg cheat sheet.

Insert a new row into DataTable

@William You can use NewRow method of the datatable to get a blank datarow and with the schema as that of the datatable. You can populate this datarow and then add the row to the datatable using .Rows.Add(DataRow) OR .Rows.InsertAt(DataRow, Position). The following is a stub code which you can modify as per your convenience.

//Creating dummy datatable for testing
DataTable dt = new DataTable();
DataColumn dc = new DataColumn("col1", typeof(String));
dt.Columns.Add(dc);

dc = new DataColumn("col2", typeof(String));
dt.Columns.Add(dc);

dc = new DataColumn("col3", typeof(String));
dt.Columns.Add(dc);

dc = new DataColumn("col4", typeof(String));
dt.Columns.Add(dc);

DataRow dr = dt.NewRow();

dr[0] = "coldata1";
dr[1] = "coldata2";
dr[2] = "coldata3";
dr[3] = "coldata4";

dt.Rows.Add(dr);//this will add the row at the end of the datatable
//OR
int yourPosition = 0;
dt.Rows.InsertAt(dr, yourPosition);

How to invoke a Linux shell command from Java

Building on @Tim's example to make a self-contained method:

import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
import java.util.ArrayList;

public class Shell {

    /** Returns null if it failed for some reason.
     */
    public static ArrayList<String> command(final String cmdline,
    final String directory) {
        try {
            Process process = 
                new ProcessBuilder(new String[] {"bash", "-c", cmdline})
                    .redirectErrorStream(true)
                    .directory(new File(directory))
                    .start();

            ArrayList<String> output = new ArrayList<String>();
            BufferedReader br = new BufferedReader(
                new InputStreamReader(process.getInputStream()));
            String line = null;
            while ( (line = br.readLine()) != null )
                output.add(line);

            //There should really be a timeout here.
            if (0 != process.waitFor())
                return null;

            return output;

        } catch (Exception e) {
            //Warning: doing this is no good in high quality applications.
            //Instead, present appropriate error messages to the user.
            //But it's perfectly fine for prototyping.

            return null;
        }
    }

    public static void main(String[] args) {
        test("which bash");

        test("find . -type f -printf '%T@\\\\t%p\\\\n' "
            + "| sort -n | cut -f 2- | "
            + "sed -e 's/ /\\\\\\\\ /g' | xargs ls -halt");

    }

    static void test(String cmdline) {
        ArrayList<String> output = command(cmdline, ".");
        if (null == output)
            System.out.println("\n\n\t\tCOMMAND FAILED: " + cmdline);
        else
            for (String line : output)
                System.out.println(line);

    }
}

(The test example is a command that lists all files in a directory and its subdirectories, recursively, in chronological order.)

By the way, if somebody can tell me why I need four and eight backslashes there, instead of two and four, I can learn something. There is one more level of unescaping happening than what I am counting.

Edit: Just tried this same code on Linux, and there it turns out that I need half as many backslashes in the test command! (That is: the expected number of two and four.) Now it's no longer just weird, it's a portability problem.

The page cannot be displayed because an internal server error has occurred on server

I just got this error and it was caused by a duplicate static content MIME type in the web.config

This error was being returned only on static files - eg images, css, js files were all saying this error (text by itself, no other html or text in the response).

The way to debug this is to look in web config under static content. Here we have a json file extension loaded. This was required on IIS7 but will kill the app if used on IIS8 because json is now pre-loaded at the server level.

    <staticContent>
        <clientCache cacheControlMode="UseMaxAge" cacheControlMaxAge="30.00:00:00" />
        <mimeMap fileExtension=".json" mimeType="application/json" />
    </staticContent>

So solution is to remove any of these mimeType entries one at a time to confirm which are needed and which kill your app!

Update

Actually the best solution was provided by a commenter here. You can remove and then add, which will always work regardless of whether it is already defined or not. Like this:

<remove fileExtension=".json" /> 
<mimeMap fileExtension=".json" mimeType="application/json" />

How to compare a local git branch with its remote branch?

Example

git diff 'master' 'testlocalBranch'

If you are using editor like webstorm, you can right click on file select compare with branch and type/select your branch.

enter image description here

enter image description here

Disabled href tag

The best answer is always the simplest. No need for any coding.

If the (a) anchor tag has no href attribute, it is only a placeholder for a hyperlink. Supported by all browsers!

_x000D_
_x000D_
<a href="/">free web counters</a><br  />_x000D_
<a "/">free web counters</a>
_x000D_
_x000D_
_x000D_

Create a dictionary with list comprehension

Here is another example of dictionary creation using dict comprehension:

What i am tring to do here is to create a alphabet dictionary where each pair; is the english letter and its corresponding position in english alphabet

>>> import string
>>> dict1 = {value: (int(key) + 1) for key, value in 
enumerate(list(string.ascii_lowercase))}
>>> dict1
{'a': 1, 'c': 3, 'b': 2, 'e': 5, 'd': 4, 'g': 7, 'f': 6, 'i': 9, 'h': 8, 
'k': 11, 'j': 10, 'm': 13, 'l': 12, 'o': 15, 'n': 14, 'q': 17, 'p': 16, 's': 
19, 'r': 18, 'u': 21, 't': 20, 'w': 23, 'v': 22, 'y': 25, 'x': 24, 'z': 26}
>>> 

Notice the use of enumerate here to get a list of alphabets and their indexes in the list and swapping the alphabets and indices to generate the key value pair for dictionary

Hope it gives a good idea of dictionary comp to you and encourages you to use it more often to make your code compact

printf \t option

That's something controlled by your terminal, not by printf.

printf simply sends a \t to the output stream (which can be a tty, a file etc), it doesn't send a number of spaces.

Can the jQuery UI Datepicker be made to disable Saturdays and Sundays (and holidays)?

This version of code will make u to get the holiday dates from the sql database and disable the specified date in the UI Datepicker


$(document).ready(function (){
  var holiDays = (function () {
    var val = null;
    $.ajax({
        'async': false,
        'global': false,
        'url': 'getdate.php',
        'success': function (data) {
            val = data;
        }
    });
    return val;
    })();
  var natDays = holiDays.split('');

  function nationalDays(date) {
    var m = date.getMonth();
    var d = date.getDate();
    var y = date.getFullYear();

    for (var i = 0; i ‘ natDays.length-1; i++) {
    var myDate = new Date(natDays[i]);
      if ((m == (myDate.getMonth())) && (d == (myDate.getDate())) && (y == (myDate.getFullYear())))
      {
        return [false];
      }
    }
    return [true];
  }

  function noWeekendsOrHolidays(date) {
    var noWeekend = $.datepicker.noWeekends(date);
      if (noWeekend[0]) {
        return nationalDays(date);
      } else {
        return noWeekend;
    }
  }
  $(function() { 
    $("#shipdate").datepicker({
      minDate: 0,
      dateFormat: 'DD, d MM, yy',
      beforeShowDay: noWeekendsOrHolidays,
      showOn: 'button',
      buttonImage: 'images/calendar.gif', 
      buttonImageOnly: true
     });
  });
});

Create a Database in sql and put you holiday dates in MM/DD/YYYY format as Varchar Put the below contents in a file getdate.php


[php]
$sql="SELECT dates FROM holidaydates";
$result = mysql_query($sql);
$chkdate = $_POST['chkdate'];
$str='';
while($row = mysql_fetch_array($result))
{
$str .=$row[0].'';
}
echo $str;
[/php]

Happy Coding !!!! :-)

OS X Bash, 'watch' command

Here's a slightly changed version of this answer that:

  • checks for valid args
  • shows a date and duration title at the top
  • moves the "duration" argument to be the 1st argument, so complex commands can be easily passed as the remaining arguments.

To use it:

  • Save this to ~/bin/watch
  • execute chmod 700 ~/bin/watch in a terminal to make it executable.
  • try it by running watch 1 echo "hi there"

~/bin/watch

#!/bin/bash

function show_help()
{
  echo ""
  echo "usage: watch [sleep duration in seconds] [command]"
  echo ""
  echo "e.g. To cat a file every second, run the following"
  echo ""
  echo "     watch 1 cat /tmp/it.txt" 
  exit;
}

function show_help_if_required()
{
  if [ "$1" == "help" ]
  then
      show_help
  fi
  if [ -z "$1" ]
    then
      show_help
  fi
}

function require_numeric_value()
{
  REG_EX='^[0-9]+$'
  if ! [[ $1 =~ $REG_EX ]] ; then
    show_help
  fi
}

show_help_if_required $1
require_numeric_value $1

DURATION=$1
shift

while :; do 
  clear
  echo "Updating every $DURATION seconds. Last updated $(date)"
  bash -c "$*"
  sleep $DURATION
done

Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()'

I installed webapi with it via the helppages nuget package. That package replaced most of the asp.net mvc 4 binaries with beta versions which didn't work well together with the rest of the project. Fix was to restore the original mvc 4 dll's and all was good.

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

I suggest removing the below code from getMails

 .catch(error => { throw error})

In your main function you should put await and related code in Try block and also add one catch block where you failure code.


you function gmaiLHelper.getEmails should return a promise which has reject and resolve in it.

Now while calling and using await put that in try catch block(remove the .catch) as below.

router.get("/emailfetch", authCheck, async (req, res) => {
  //listing messages in users mailbox 
try{
  let emailFetch = await gmaiLHelper.getEmails(req.user._doc.profile_id , '/messages', req.user.accessToken)
}
catch (error) { 
 // your catch block code goes here
})

Differences between "BEGIN RSA PRIVATE KEY" and "BEGIN PRIVATE KEY"

Have a look at <openssl/pem.h>. It gives possible BEGIN markers.

Copying the content from the above link for quick reference:

#define PEM_STRING_X509_OLD "X509 CERTIFICATE"
#define PEM_STRING_X509     "CERTIFICATE"
#define PEM_STRING_X509_PAIR    "CERTIFICATE PAIR"
#define PEM_STRING_X509_TRUSTED "TRUSTED CERTIFICATE"
#define PEM_STRING_X509_REQ_OLD "NEW CERTIFICATE REQUEST"
#define PEM_STRING_X509_REQ "CERTIFICATE REQUEST"
#define PEM_STRING_X509_CRL "X509 CRL"
#define PEM_STRING_EVP_PKEY "ANY PRIVATE KEY"
#define PEM_STRING_PUBLIC   "PUBLIC KEY"
#define PEM_STRING_RSA      "RSA PRIVATE KEY"
#define PEM_STRING_RSA_PUBLIC   "RSA PUBLIC KEY"
#define PEM_STRING_DSA      "DSA PRIVATE KEY"
#define PEM_STRING_DSA_PUBLIC   "DSA PUBLIC KEY"
#define PEM_STRING_PKCS7    "PKCS7"
#define PEM_STRING_PKCS7_SIGNED "PKCS #7 SIGNED DATA"
#define PEM_STRING_PKCS8    "ENCRYPTED PRIVATE KEY"
#define PEM_STRING_PKCS8INF "PRIVATE KEY"
#define PEM_STRING_DHPARAMS "DH PARAMETERS"
#define PEM_STRING_DHXPARAMS    "X9.42 DH PARAMETERS"
#define PEM_STRING_SSL_SESSION  "SSL SESSION PARAMETERS"
#define PEM_STRING_DSAPARAMS    "DSA PARAMETERS"
#define PEM_STRING_ECDSA_PUBLIC "ECDSA PUBLIC KEY"
#define PEM_STRING_ECPARAMETERS "EC PARAMETERS"
#define PEM_STRING_ECPRIVATEKEY "EC PRIVATE KEY"
#define PEM_STRING_PARAMETERS   "PARAMETERS"
#define PEM_STRING_CMS      "CMS"

is there a require for json in node.js

No. Either use readFile or readFileSync (The latter only at startup time).

Or use an existing library like

Alternatively write your config in a js file rather then a json file like

module.exports = {
  // json
}

Detect if a browser in a mobile device (iOS/Android phone/tablet) is used

Update (June 2016): I now try to support touch and mouse input on every resolution, since the device landscape is slowly blurring the lines between what things are and aren't touch devices. iPad Pros are touch-only with the resolution of a 13" laptop. Windows laptops now frequently come with touch screens.

Other similar SO answers (see other answer on this question) might have different ways to try to figure out what sort of device the user is using, but none of them are fool-proof. I encourage you to check those answers out if you absolutely need to try to determine the device.


iPhones, for one, ignore the handheld query (Source). And I wouldn't be surprised if other smartphones do, too, for similar reasons.

The current best way that I use to detect a mobile device is to know its width and use the corresponding media query to catch it. That link there lists some popular ones. A quick Google search would yield you any others you might need, I'm sure.

For more iPhone-specific ones (such as Retina display), check out that first link I posted.

Formatting a number with exactly two decimals in JavaScript

To format a number using fixed-point notation, you can simply use the toFixed method:

(10.8).toFixed(2); // "10.80"

var num = 2.4;
alert(num.toFixed(2)); // "2.40"

Note that toFixed() returns a string.

IMPORTANT: Note that toFixed does not round 90% of the time, it will return the rounded value, but for many cases, it doesn't work.

For instance:

2.005.toFixed(2) === "2.00"

UPDATE:

Nowadays, you can use the Intl.NumberFormat constructor. It's part of the ECMAScript Internationalization API Specification (ECMA402). It has pretty good browser support, including even IE11, and it is fully supported in Node.js.

_x000D_
_x000D_
const formatter = new Intl.NumberFormat('en-US', {
   minimumFractionDigits: 2,      
   maximumFractionDigits: 2,
});

console.log(formatter.format(2.005)); // "2.01"
console.log(formatter.format(1.345)); // "1.35"
_x000D_
_x000D_
_x000D_

You can alternatively use the toLocaleString method, which internally will use the Intl API:

_x000D_
_x000D_
const format = (num, decimals) => num.toLocaleString('en-US', {
   minimumFractionDigits: 2,      
   maximumFractionDigits: 2,
});


console.log(format(2.005)); // "2.01"
console.log(format(1.345)); // "1.35"
_x000D_
_x000D_
_x000D_

This API also provides you a wide variety of options to format, like thousand separators, currency symbols, etc.

Compile error: package javax.servlet does not exist

Even after trying suggested solution, it was not solving my problem because there where many instance of java path were entered by me.

  1. I removed all java related path (different version java) from "Path, JAVA_HOME, JRE_HOME" and created from fresh.

  2. i have set (path may changes as per different installation)
    a. JAVA_HOME as C:\Program Files\Java\jdk1.8.0_191
    b. JRE_HOME as C:\Program Files\Java\jdk1.8.0_191\jre\lib
    c. add binary file path in path: C:\Program Files\Java\jdk1.8.0_191\bin
    d. CLASSPATH as C:\apache-tomcat-7.0.93\lib

  3. never try in the same command prompt if its already open while doing changes/creting system/user variables. close it and open new one.

Reference Image: enter image description here

Jquery Ajax Loading image

Try something like this:

<div id="LoadingImage" style="display: none">
  <img src="" />
</div>

<script>
  function ajaxCall(){
    $("#LoadingImage").show();
      $.ajax({ 
        type: "GET", 
        url: surl, 
        dataType: "jsonp", 
        cache : false, 
        jsonp : "onJSONPLoad", 
        jsonpCallback: "newarticlescallback", 
        crossDomain: "true", 
        success: function(response) { 
          $("#LoadingImage").hide();
          alert("Success"); 
        }, 
        error: function (xhr, status) {  
          $("#LoadingImage").hide();
          alert('Unknown error ' + status); 
        }    
      });  
    }
</script>

Why Does OAuth v2 Have Both Access and Refresh Tokens?

To further simplify B T's answer: Use refresh tokens when you don't typically want the user to have to type in credentials again, but still want the power to be able to revoke the permissions (by revoking the refresh token)

You cannot revoke an access token, only a refresh token.

How to bind WPF button to a command in ViewModelBase?

 <Grid >
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <Button Command="{Binding ClickCommand}" Width="100" Height="100" Content="wefwfwef"/>
</Grid>

the code behind for the window:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewModelBase();
    }
}

The ViewModel:

public class ViewModelBase
{
    private ICommand _clickCommand;
    public ICommand ClickCommand
    {
        get
        {
            return _clickCommand ?? (_clickCommand = new CommandHandler(() => MyAction(), ()=> CanExecute));
        }
    }
     public bool CanExecute
     {
        get
        {
            // check if executing is allowed, i.e., validate, check if a process is running, etc. 
            return true/false;
        }
     }

    public void MyAction()
    {

    }
}

Command Handler:

 public class CommandHandler : ICommand
{
    private Action _action;
    private Func<bool> _canExecute;

    /// <summary>
    /// Creates instance of the command handler
    /// </summary>
    /// <param name="action">Action to be executed by the command</param>
    /// <param name="canExecute">A bolean property to containing current permissions to execute the command</param>
    public CommandHandler(Action action, Func<bool> canExecute)
    {
        _action = action;
        _canExecute = canExecute;
    }

    /// <summary>
    /// Wires CanExecuteChanged event 
    /// </summary>
    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    /// <summary>
    /// Forcess checking if execute is allowed
    /// </summary>
    /// <param name="parameter"></param>
    /// <returns></returns>
    public bool CanExecute(object parameter)
    {
        return _canExecute.Invoke();
    }

    public void Execute(object parameter)
    {
        _action();
    }
}

I hope this will give you the idea.

Android global variable

You can create a Global Class like this:

public class GlobalClass extends Application{

    private String name;
    private String email;

    public String getName() {
        return name;
    }

    public void setName(String aName) {
        name = aName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String aEmail) {
        email = aEmail;
    }
}

Then define it in the manifest:

<application
    android:name="com.example.globalvariable.GlobalClass" ....

Now you can set values to global variable like this:

final GlobalClass globalVariable = (GlobalClass) getApplicationContext();
globalVariable.setName("Android Example context variable");

You can get those values like this:

final GlobalClass globalVariable = (GlobalClass) getApplicationContext();
final String name  = globalVariable.getName();

Please find complete example from this blog Global Variables

Replacing backslashes with forward slashes with str_replace() in php

Single quoted php string variable works.

$str = 'http://www.domain.com/data/images\flags/en.gif';
$str = str_replace('\\', '/', $str);

Char array to hex string C++

You could use std::hex

Eg.

std::cout << std::hex << packet;

The specified type member is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported

In this case, one of the easiest and best approach is to first cast it to list and then use where or select.

result = result.ToList().where(p => date >= p.DOB);

How to recover stashed uncommitted changes

To make this simple, you have two options to reapply your stash:

  1. git stash pop - Restore back to the saved state, but it deletes the stash from the temporary storage.
  2. git stash apply - Restore back to the saved state and leaves the stash list for possible later reuse.

You can read in more detail about git stashes in this article.

Add a custom attribute to a Laravel / Eloquent model on load?

The last thing on the Laravel Eloquent doc page is:

protected $appends = array('is_admin');

That can be used automatically to add new accessors to the model without any additional work like modifying methods like ::toArray().

Just create getFooBarAttribute(...) accessor and add the foo_bar to $appends array.

How to view .img files?

OSFMount , MagicDisc , Gizmo Director/Gizmo Drive , The Takeaway .

All these work well on .img files

Spring data jpa- No bean named 'entityManagerFactory' is defined; Injection of autowired dependencies failed

In your application context, change the bean with id from emf to entityManagerFactory:

<bean id="emf"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="packagesToScan" value="org.wahid.cse.entity" />
    <property name="dataSource" ref="dataSource" />

    <property name="jpaProperties">
        <props>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.hbm2ddl.auto">create</prop>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
        </props>
    </property>

    <property name="persistenceProvider">
        <bean class="org.hibernate.jpa.HibernatePersistenceProvider"></bean>
    </property>

</bean>

To

<bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="packagesToScan" value="org.wahid.cse.entity" />
    <property name="dataSource" ref="dataSource" />

    <property name="jpaProperties">
        <props>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.hbm2ddl.auto">create</prop>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
        </props>
    </property>

    <property name="persistenceProvider">
        <bean class="org.hibernate.jpa.HibernatePersistenceProvider"></bean>
    </property>

</bean>

onClick function of an input type="button" not working

You've forgot to define an onclick attribute to do something when the button is clicked, so nothing happening is the correct execution, see below;

<input type="button" id="moreFields" onclick="moreFields()" value="Give me more fields!"  />
                                     ----------------------

getResources().getColor() is deprecated

It looks like the best approach is to use:

ContextCompat.getColor(context, R.color.color_name)

eg:

yourView.setBackgroundColor(ContextCompat.getColor(applicationContext,
                            R.color.colorAccent))

This will choose the Marshmallow two parameter method or the pre-Marshmallow method appropriately.

Is System.nanoTime() completely useless?

Java is crossplatform, and nanoTime is platform-dependent. If you use Java - when don't use nanoTime. I found real bugs across different jvm implementations with this function.

Selecting between two dates within a DateTime field - SQL Server

select * 
from blah 
where DatetimeField between '22/02/2009 09:00:00.000' and '23/05/2009 10:30:00.000'

Depending on the country setting for the login, the month/day may need to be swapped around.

Cannot execute RUN mkdir in a Dockerfile

The problem is that /var/www doesn't exist either, and mkdir isn't recursive by default -- it expects the immediate parent directory to exist.

Use:

mkdir -p /var/www/app

...or install a package that creates a /var/www prior to reaching this point in your Dockerfile.

Is "else if" faster than "switch() case"?

I'd say the switch is the way to go, it is both faster and better practise.

There are various links such as (http://www.blackwasp.co.uk/SpeedTestIfElseSwitch.aspx) that show benchmark tests comparing the two.

SignalR - Sending a message to a specific user using (IUserIdProvider) *NEW 2.0.0*

For anyone trying to do this in asp.net core. You can use claims.

public class CustomEmailProvider : IUserIdProvider
{
    public virtual string GetUserId(HubConnectionContext connection)
    {
        return connection.User?.FindFirst(ClaimTypes.Email)?.Value;
    }
}

Any identifier can be used, but it must be unique. If you use a name identifier for example, it means if there are multiple users with the same name as the recipient, the message would be delivered to them as well. I have chosen email because it is unique to every user.

Then register the service in the startup class.

services.AddSingleton<IUserIdProvider, CustomEmailProvider>();

Next. Add the claims during user registration.

var result = await _userManager.CreateAsync(user, Model.Password);
if (result.Succeeded)
{
    await _userManager.AddClaimAsync(user, new Claim(ClaimTypes.Email, Model.Email));
}

To send message to the specific user.

public class ChatHub : Hub
{
    public async Task SendMessage(string receiver, string message)
    {
        await Clients.User(receiver).SendAsync("ReceiveMessage", message);
    }
}

Note: The message sender won't be notified the message is sent. If you want a notification on the sender's end. Change the SendMessage method to this.

public async Task SendMessage(string sender, string receiver, string message)
{
    await Clients.Users(sender, receiver).SendAsync("ReceiveMessage", message);
}

These steps are only necessary if you need to change the default identifier. Otherwise, skip to the last step where you can simply send messages by passing userIds or connectionIds to SendMessage. For more

Bitwise operation and usage

There may be a better way to find where an array element is between two values, but as this example shows, the & works here, whereas and does not.

import numpy as np
a=np.array([1.2, 2.3, 3.4])
np.where((a>2) and (a<3))      
#Result: Value Error
np.where((a>2) & (a<3))
#Result: (array([1]),)

Checking for multiple conditions using "when" on single task in ansible

You can use like this.

when: condition1 == "condition1" or condition2 == "condition2"

Link to official docs: The When Statement.

Also Please refer to this gist: https://gist.github.com/marcusphi/6791404

ORA-12154: TNS:could not resolve the connect identifier specified (PLSQL Developer)

As I can't add a comment, just thought I'd post this for completion. tufy's answer is correct, it's to do with parenthesis (brackets) in the path to the application being run.

There is an existing networking bug where the networking layer is unable to parse program locations that contain parenthesis in the path to the executable which is attempting to connect to Oracle.

Filed with Oracle, Bug 3807408 refers.

Source

How do I accomplish an if/else in mustache.js?

This is something you solve in the "controller", which is the point of logicless templating.

// some function that retreived data through ajax
function( view ){

   if ( !view.avatar ) {
      // DEFAULTS can be a global settings object you define elsewhere
      // so that you don't have to maintain these values all over the place
      // in your code.
      view.avatar = DEFAULTS.AVATAR;
   }

   // do template stuff here

}

This is actually a LOT better then maintaining image url's or other media that might or might not change in your templates, but takes some getting used to. The point is to unlearn template tunnel vision, an avatar img url is bound to be used in other templates, are you going to maintain that url on X templates or a single DEFAULTS settings object? ;)

Another option is to do the following:

// augment view
view.hasAvatar = !!view.avatar;
view.noAvatar = !view.avatar;

And in the template:

{{#hasAvatar}}
    SHOW AVATAR
{{/hasAvatar}}
{{#noAvatar}}
    SHOW DEFAULT
{{/noAvatar}}

But that's going against the whole meaning of logicless templating. If that's what you want to do, you want logical templating and you should not use Mustache, though do give it yourself a fair chance of learning this concept ;)

jQuery remove special characters from string and more

Remove numbers, underscore, white-spaces and special characters from the string sentence.

str.replace(/[0-9`~!@#$%^&*()_|+\-=?;:'",.<>\{\}\[\]\\\/]/gi,'');

Demo

String replacement in java, similar to a velocity template

Take a look at the java.text.MessageFormat class, MessageFormat takes a set of objects, formats them, then inserts the formatted strings into the pattern at the appropriate places.

Object[] params = new Object[]{"hello", "!"};
String msg = MessageFormat.format("{0} world {1}", params);

Spark: Add column to dataframe conditionally

Try withColumn with the function when as follows:

val sqlContext = new SQLContext(sc)
import sqlContext.implicits._ // for `toDF` and $""
import org.apache.spark.sql.functions._ // for `when`

val df = sc.parallelize(Seq((4, "blah", 2), (2, "", 3), (56, "foo", 3), (100, null, 5)))
    .toDF("A", "B", "C")

val newDf = df.withColumn("D", when($"B".isNull or $"B" === "", 0).otherwise(1))

newDf.show() shows

+---+----+---+---+
|  A|   B|  C|  D|
+---+----+---+---+
|  4|blah|  2|  1|
|  2|    |  3|  0|
| 56| foo|  3|  1|
|100|null|  5|  0|
+---+----+---+---+

I added the (100, null, 5) row for testing the isNull case.

I tried this code with Spark 1.6.0 but as commented in the code of when, it works on the versions after 1.4.0.

How do I use ROW_NUMBER()?

Though I agree with others that you could use count() to get the total number of rows, here is how you can use the row_count():

  1. To get the total no of rows:

    with temp as (
        select row_number() over (order by id) as rownum
        from table_name 
    )
    select max(rownum) from temp
  2. To get the row numbers where name is Matt:

    with temp as (
        select name, row_number() over (order by id) as rownum
        from table_name
    )
    select rownum from temp where name like 'Matt'

You can further use min(rownum) or max(rownum) to get the first or last row for Matt respectively.

These were very simple implementations of row_number(). You can use it for more complex grouping. Check out my response on Advanced grouping without using a sub query

how to rotate text left 90 degree and cell size is adjusted according to text in html

Unfortunately while I thought these answers may have worked for me, I struggled with a solution, as I'm using tables inside responsive tables - where the overflow-x is played with.

So, with that in mind, have a look at this link for a cleaner way, which doesn't have the weird width overflow issues. It worked for me in the end and was very easy to implement.

https://css-tricks.com/rotated-table-column-headers/

Windows Application has stopped working :: Event Name CLR20r3

This is just because the application is built in non unicode language fonts and you are running the system on unicode fonts. change your default non unicode fonts to arabic by going in regional settings advanced tab in control panel. That will solve your problem.

How can I display my windows user name in excel spread sheet using macros?

Range("A1").value = Environ("Username")

This is better than Application.Username, which doesn't always supply the Windows username. Thanks to Kyle for pointing this out.

  • Application Username is the name of the User set in Excel > Tools > Options
  • Environ("Username") is the name you registered for Windows; see Control Panel >System

Android: how to parse URL String with spaces to URI object?

I wrote this function:

public static String encode(@NonNull String uriString) {
    if (TextUtils.isEmpty(uriString)) {
        Assert.fail("Uri string cannot be empty!");
        return uriString;
    }
    // getQueryParameterNames is not exist then cannot iterate on queries
    if (Build.VERSION.SDK_INT < 11) {
        return uriString;
    }

    // Check if uri has valid characters
    // See https://tools.ietf.org/html/rfc3986
    Pattern allowedUrlCharacters = Pattern.compile("([A-Za-z0-9_.~:/?\\#\\[\\]@!$&'()*+,;" +
            "=-]|%[0-9a-fA-F]{2})+");
    Matcher matcher = allowedUrlCharacters.matcher(uriString);
    String validUri = null;
    if (matcher.find()) {
        validUri = matcher.group();
    }
    if (TextUtils.isEmpty(validUri) || uriString.length() == validUri.length()) {
        return uriString;
    }

    // The uriString is not encoded. Then recreate the uri and encode it this time
    Uri uri = Uri.parse(uriString);
    Uri.Builder uriBuilder = new Uri.Builder()
            .scheme(uri.getScheme())
            .authority(uri.getAuthority());
    for (String path : uri.getPathSegments()) {
        uriBuilder.appendPath(path);
    }
    for (String key : uri.getQueryParameterNames()) {
        uriBuilder.appendQueryParameter(key, uri.getQueryParameter(key));
    }
    String correctUrl = uriBuilder.build().toString();
    return correctUrl;
}

How to set OnClickListener on a RadioButton in Android?

Just in case someone else was struggeling with the accepted answer:

There are different OnCheckedChangeListener-Interfaces. I added to first one to see if a CheckBox was changed.

import android.widget.CompoundButton.OnCheckedChangeListener;

vs

import android.widget.RadioGroup.OnCheckedChangeListener;

When adding the snippet from Ricky I had errors:

The method setOnCheckedChangeListener(RadioGroup.OnCheckedChangeListener) in the type RadioGroup is not applicable for the arguments (new CompoundButton.OnCheckedChangeListener(){})

Can be fixed with answer from Ali :

new RadioGroup.OnCheckedChangeListener()

How to install trusted CA certificate on Android device?

These steps worked for me:

  1. Install Dory Certificate Android app on your mobile device: https://play.google.com/store/apps/details?id=io.tempage.dorycert&hl=en_US
  2. Connect mobile device to laptop with USB Cable.
  3. Create root folder on Internal Phone memory, copy the certificate file in that folder and disconnect cable.
  4. Open Dory Certificate Android app, click the round [+] button and select the right Import File Certificate option.
  5. Select format, provide a name (I typed same as filename), browse the certificate file and click the [OK].
  6. Three cards will list up. I ignored the card that only had the [SIGN CSR] button and proceeded to click the [INSTALL] button on the two other cards.
  7. I refreshed the PWA web app I had opened no my mobile Chrome (it is hosted on a local IIS Web Server) and voala! No chrome warning message. The green lock was there. It was Working.

Alternatively, I found these options which I had no need to try myself but looked easy to follow:

Finally, it may not be relevant but, if you are looking to create and setup a self-signed certificate (with mkcert) for your PWA app (website) hosted on a local IIS Web server, I followed this page:

https://medium.com/@aweber01/locally-trusted-development-certificates-with-mkcert-and-iis-e09410d92031

Thanks and hope it helps!! :)

How to run a class from Jar which is not the Main-Class in its Manifest file

Another similar option that I think Nick briefly alluded to in the comments is to create multiple wrapper jars. I haven't tried it, but I think they could be completely empty other than the manifest file, which should specify the main class to load as well as the inclusion of the MyJar.jar to the classpath.

MyJar1.jar\META-INF\MANIFEST.MF

Manifest-Version: 1.0
Main-Class: com.mycomp.myproj.dir1.MainClass1
Class-Path: MyJar.jar

MyJar2.jar\META-INF\MANIFEST.MF

Manifest-Version: 1.0
Main-Class: com.mycomp.myproj.dir2.MainClass2
Class-Path: MyJar.jar

etc. Then just run it with java -jar MyJar2.jar

Redirecting to a new page after successful login

Javascript redirection generated with php code:

 if($match > 0){
     $msg = 'Login Complete! Thanks';
     echo "<script> window.location.assign('index.php'); </script>";
 }
 else{
     $msg = 'Login Failed!<br /> Please make sure that you enter the correct  details and that you have activated your account.';
 }

Php redirection only:

<?php
    header("Location: index.php"); 
    exit;
?>

How can I call a WordPress shortcode within a template?

echo do_shortcode('[CONTACT-US-FORM]');

Use this in your template.

Look here for more: Do Shortcode

react-router scroll to top on every transition

My solution: a component that I'm using in my screens components (where I want a scroll to top).

import { useLayoutEffect } from 'react';

const ScrollToTop = () => {
    useLayoutEffect(() => {
        window.scrollTo(0, 0);
    }, []);

    return null;
};

export default ScrollToTop;

This preserves scroll position when going back. Using useEffect() was buggy for me, when going back the document would scroll to top and also had a blink effect when route was changed in an already scrolled document.

What's the difference between HEAD, working tree and index, in Git?

Your working tree is what is actually in the files that you are currently working on.

HEAD is a pointer to the branch or commit that you last checked out, and which will be the parent of a new commit if you make it. For instance, if you're on the master branch, then HEAD will point to master, and when you commit, that new commit will be a descendent of the revision that master pointed to, and master will be updated to point to the new commit.

The index is a staging area where the new commit is prepared. Essentially, the contents of the index are what will go into the new commit (though if you do git commit -a, this will automatically add all changes to files that Git knows about to the index before committing, so it will commit the current contents of your working tree). git add will add or update files from the working tree into your index.

Access parent DataContext from DataTemplate

I was searching how to do something similar in WPF and I got this solution:

<ItemsControl ItemsSource="{Binding MyItems,Mode=OneWay}">
<ItemsControl.ItemsPanel>
    <ItemsPanelTemplate>
        <StackPanel Orientation="Vertical" />
    </ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
    <DataTemplate>
        <RadioButton 
            Content="{Binding}" 
            Command="{Binding Path=DataContext.CustomCommand, 
                        RelativeSource={RelativeSource Mode=FindAncestor,      
                        AncestorType={x:Type ItemsControl}} }"
            CommandParameter="{Binding}" />
    </DataTemplate>
</ItemsControl.ItemTemplate>

I hope this works for somebody else. I have a data context which is set automatically to the ItemsControls, and this data context has two properties: MyItems -which is a collection-, and one command 'CustomCommand'. Because of the ItemTemplate is using a DataTemplate, the DataContext of upper levels is not directly accessible. Then the workaround to get the DC of the parent is use a relative path and filter by ItemsControl type.

Ternary operator in PowerShell

I've recently improved (open PullRequest) the ternary conditional and null-coalescing operators in the PoweShell lib 'Pscx'
Pls have a look for my solution.


My github topic branch: UtilityModule_Invoke-Operators

Functions:

Invoke-Ternary
Invoke-TernaryAsPipe
Invoke-NullCoalescing
NullCoalescingAsPipe

Aliases

Set-Alias :?:   Pscx\Invoke-Ternary                     -Description "PSCX alias"
Set-Alias ?:    Pscx\Invoke-TernaryAsPipe               -Description "PSCX alias"
Set-Alias :??   Pscx\Invoke-NullCoalescing              -Description "PSCX alias"
Set-Alias ??    Pscx\Invoke-NullCoalescingAsPipe        -Description "PSCX alias"

Usage

<condition_expression> |?: <true_expression> <false_expression>

<variable_expression> |?? <alternate_expression>

As expression you can pass:
$null, a literal, a variable, an 'external' expression ($b -eq 4) or a scriptblock {$b -eq 4}

If a variable in the variable expression is $null or not existing, the alternate expression is evaluated as output.

Identifier not found error on function call

You have to define void swapCase before the main definition.

unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard

In the “Subclass of” field, select UITableViewController.

The class title changes to xxxxTableViewController. Leave that as is.

Make sure the “Also create XIB file” option is selected.

Android sample bluetooth code to send a simple string via bluetooth

I made the following code so that even beginners can understand. Just copy the code and read comments. Note that message to be send is declared as a global variable which you can change just before sending the message. General changes can be done in Handler function.

multiplayerConnect.java

import android.annotation.SuppressLint;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;

public class multiplayerConnect extends AppCompatActivity {

public static final int REQUEST_ENABLE_BT=1;
ListView lv_paired_devices;
Set<BluetoothDevice> set_pairedDevices;
ArrayAdapter adapter_paired_devices;
BluetoothAdapter bluetoothAdapter;
public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
public static final int MESSAGE_READ=0;
public static final int MESSAGE_WRITE=1;
public static final int CONNECTING=2;
public static final int CONNECTED=3;
public static final int NO_SOCKET_FOUND=4;


String bluetooth_message="00";




@SuppressLint("HandlerLeak")
Handler mHandler=new Handler()
{
    @Override
    public void handleMessage(Message msg_type) {
        super.handleMessage(msg_type);

        switch (msg_type.what){
            case MESSAGE_READ:

                byte[] readbuf=(byte[])msg_type.obj;
                String string_recieved=new String(readbuf);

                //do some task based on recieved string

                break;
            case MESSAGE_WRITE:

                if(msg_type.obj!=null){
                    ConnectedThread connectedThread=new ConnectedThread((BluetoothSocket)msg_type.obj);
                    connectedThread.write(bluetooth_message.getBytes());

                }
                break;

            case CONNECTED:
                Toast.makeText(getApplicationContext(),"Connected",Toast.LENGTH_SHORT).show();
                break;

            case CONNECTING:
                Toast.makeText(getApplicationContext(),"Connecting...",Toast.LENGTH_SHORT).show();
                break;

            case NO_SOCKET_FOUND:
                Toast.makeText(getApplicationContext(),"No socket found",Toast.LENGTH_SHORT).show();
                break;
        }
    }
};



@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.multiplayer_bluetooth);
    initialize_layout();
    initialize_bluetooth();
    start_accepting_connection();
    initialize_clicks();

}

public void start_accepting_connection()
{
    //call this on button click as suited by you

    AcceptThread acceptThread = new AcceptThread();
    acceptThread.start();
    Toast.makeText(getApplicationContext(),"accepting",Toast.LENGTH_SHORT).show();
}
public void initialize_clicks()
{
    lv_paired_devices.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id)
        {
            Object[] objects = set_pairedDevices.toArray();
            BluetoothDevice device = (BluetoothDevice) objects[position];

            ConnectThread connectThread = new ConnectThread(device);
            connectThread.start();

            Toast.makeText(getApplicationContext(),"device choosen "+device.getName(),Toast.LENGTH_SHORT).show();
        }
    });
}

public void initialize_layout()
{
    lv_paired_devices = (ListView)findViewById(R.id.lv_paired_devices);
    adapter_paired_devices = new ArrayAdapter(getApplicationContext(),R.layout.support_simple_spinner_dropdown_item);
    lv_paired_devices.setAdapter(adapter_paired_devices);
}

public void initialize_bluetooth()
{
    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (bluetoothAdapter == null) {
        // Device doesn't support Bluetooth
        Toast.makeText(getApplicationContext(),"Your Device doesn't support bluetooth. you can play as Single player",Toast.LENGTH_SHORT).show();
        finish();
    }

    //Add these permisions before
//        <uses-permission android:name="android.permission.BLUETOOTH" />
//        <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
//        <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
//        <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

    if (!bluetoothAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
    }

    else {
        set_pairedDevices = bluetoothAdapter.getBondedDevices();

        if (set_pairedDevices.size() > 0) {

            for (BluetoothDevice device : set_pairedDevices) {
                String deviceName = device.getName();
                String deviceHardwareAddress = device.getAddress(); // MAC address

                adapter_paired_devices.add(device.getName() + "\n" + device.getAddress());
            }
        }
    }
}


public class AcceptThread extends Thread
{
    private final BluetoothServerSocket serverSocket;

    public AcceptThread() {
        BluetoothServerSocket tmp = null;
        try {
            // MY_UUID is the app's UUID string, also used by the client code
            tmp = bluetoothAdapter.listenUsingRfcommWithServiceRecord("NAME",MY_UUID);
        } catch (IOException e) { }
        serverSocket = tmp;
    }

    public void run() {
        BluetoothSocket socket = null;
        // Keep listening until exception occurs or a socket is returned
        while (true) {
            try {
                socket = serverSocket.accept();
            } catch (IOException e) {
                break;
            }

            // If a connection was accepted
            if (socket != null)
            {
                // Do work to manage the connection (in a separate thread)
                mHandler.obtainMessage(CONNECTED).sendToTarget();
            }
        }
    }
}


private class ConnectThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;

    public ConnectThread(BluetoothDevice device) {
        // Use a temporary object that is later assigned to mmSocket,
        // because mmSocket is final
        BluetoothSocket tmp = null;
        mmDevice = device;

        // Get a BluetoothSocket to connect with the given BluetoothDevice
        try {
            // MY_UUID is the app's UUID string, also used by the server code
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
        } catch (IOException e) { }
        mmSocket = tmp;
    }

    public void run() {
        // Cancel discovery because it will slow down the connection
        bluetoothAdapter.cancelDiscovery();

        try {
            // Connect the device through the socket. This will block
            // until it succeeds or throws an exception
            mHandler.obtainMessage(CONNECTING).sendToTarget();

            mmSocket.connect();
        } catch (IOException connectException) {
            // Unable to connect; close the socket and get out
            try {
                mmSocket.close();
            } catch (IOException closeException) { }
            return;
        }

        // Do work to manage the connection (in a separate thread)
//            bluetooth_message = "Initial message"
//            mHandler.obtainMessage(MESSAGE_WRITE,mmSocket).sendToTarget();
    }

    /** Will cancel an in-progress connection, and close the socket */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}
private class ConnectedThread extends Thread {

    private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;

    public ConnectedThread(BluetoothSocket socket) {
        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;

        // Get the input and output streams, using temp objects because
        // member streams are final
        try {
            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();
        } catch (IOException e) { }

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }

    public void run() {
        byte[] buffer = new byte[2];  // buffer store for the stream
        int bytes; // bytes returned from read()

        // Keep listening to the InputStream until an exception occurs
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.read(buffer);
                // Send the obtained bytes to the UI activity
                mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer).sendToTarget();

            } catch (IOException e) {
                break;
            }
        }
    }

    /* Call this from the main activity to send data to the remote device */
    public void write(byte[] bytes) {
        try {
            mmOutStream.write(bytes);
        } catch (IOException e) { }
    }

    /* Call this from the main activity to shutdown the connection */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}
}

multiplayer_bluetooth.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Challenge player"/>

    <ListView
        android:id="@+id/lv_paired_devices"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1">
    </ListView>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Make sure Device is paired"/>

</LinearLayout>

Javascript loading CSV file into an array

You can't use AJAX to fetch files from the user machine. This is absolutely the wrong way to go about it.

Use the FileReader API:

<input type="file" id="file input">

js:

console.log(document.getElementById("file input").files); // list of File objects

var file = document.getElementById("file input").files[0];
var reader = new FileReader();
content = reader.readAsText(file);
console.log(content);

Then parse content as CSV. Keep in mind that your parser currently does not deal with escaped values in CSV like: value1,value2,"value 3","value ""4"""

How to make an app's background image repeat

Ok, here's what I've got in my app. It includes a hack to prevent ListViews from going black while scrolling.

drawable/app_background.xml:

<?xml version="1.0" encoding="utf-8"?>
    <bitmap xmlns:android="http://schemas.android.com/apk/res/android"
        android:src="@drawable/actual_pattern_image"
        android:tileMode="repeat" />

values/styles.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>

  <style name="app_theme" parent="android:Theme">
    <item name="android:windowBackground">@drawable/app_background</item>
    <item name="android:listViewStyle">@style/TransparentListView</item>
    <item name="android:expandableListViewStyle">@style/TransparentExpandableListView</item>
  </style>

  <style name="TransparentListView" parent="@android:style/Widget.ListView">
    <item name="android:cacheColorHint">@android:color/transparent</item>
  </style>

  <style name="TransparentExpandableListView" parent="@android:style/Widget.ExpandableListView">
    <item name="android:cacheColorHint">@android:color/transparent</item>
  </style>

</resources>

AndroidManifest.xml:

//
<application android:theme="@style/app_theme">
//

How to enable mbstring from php.ini?

All XAMPP packages come with Multibyte String (php_mbstring.dll) extension installed.

If you have accidentally removed DLL file from php/ext folder, just add it back (get the copy from XAMPP zip archive - its downloadable).

If you have deleted the accompanying INI configuration line from php.ini file, add it back as well:

extension=php_mbstring.dll

Also, ensure to restart your webserver (Apache) using XAMPP control panel.

Additional Info on Enabling PHP Extensions

  • install extension (e.g. put php_mbstring.dll into /XAMPP/php/ext directory)
  • in php.ini, ensure extension directory specified (e.g. extension_dir = "ext")
  • ensure correct build of DLL file (e.g. 32bit thread-safe VC9 only works with DLL files built using exact same tools and configuration: 32bit thread-safe VC9)
  • ensure PHP API versions match (If not, once you restart the webserver you will receive related error.)

react-native - Fit Image in containing View, not the whole screen size

Anyone over here who wants his image to fit in full screen without any crop (in both portrait and landscape mode), use this:

image: {
    flex: 1,
    width: '100%',
    height: '100%',
    resizeMode: 'contain',
},