#Aspen | Programs & Examples on Aspen

Remove all child nodes from a parent?

A other users suggested,

.empty()

is good enought, because it removes all descendant nodes (both tag-nodes and text-nodes) AND all kind of data stored inside those nodes. See the JQuery's API empty documentation.

If you wish to keep data, like event handlers for example, you should use

.detach()

as described on the JQuery's API detach documentation.

The method .remove() could be usefull for similar purposes.

How to open link in new tab on html?

When to use target='_blank' :

The HTML version (Some devices not support it):

<a href="http://chriscoyier.net" target="_blank">This link will open in new window/tab</a>

The JavaScript version for all Devices :

The use of rel="external" is perfectly valid

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script type="text/javascript">
    $('a[rel="external"]').attr('target', '_blank');
</script>

and for Jquery can try with the below one:

$("#content a[href^='http://']").attr("target","_blank");

If browser setting don't allow you to open in new windows :

href = "google.com";
onclick="window.open (this.href, ''); return false";

Programmatically trigger "select file" dialog box

This worked for me:

$('#fileInput').val('');

Is it possible to have empty RequestParam values use the defaultValue?

You can keep primitive type by setting default value, in the your case just add "required = false" property:

@RequestParam(value = "i", required = false, defaultValue = "10") int i

P.S. This page from Spring documentation might be useful: Annotation Type RequestParam

Rotation of 3D vector?

It can also be solved using quaternion theory:

def angle_axis_quat(theta, axis):
    """
    Given an angle and an axis, it returns a quaternion.
    """
    axis = np.array(axis) / np.linalg.norm(axis)
    return np.append([np.cos(theta/2)],np.sin(theta/2) * axis)

def mult_quat(q1, q2):
    """
    Quaternion multiplication.
    """
    q3 = np.copy(q1)
    q3[0] = q1[0]*q2[0] - q1[1]*q2[1] - q1[2]*q2[2] - q1[3]*q2[3]
    q3[1] = q1[0]*q2[1] + q1[1]*q2[0] + q1[2]*q2[3] - q1[3]*q2[2]
    q3[2] = q1[0]*q2[2] - q1[1]*q2[3] + q1[2]*q2[0] + q1[3]*q2[1]
    q3[3] = q1[0]*q2[3] + q1[1]*q2[2] - q1[2]*q2[1] + q1[3]*q2[0]
    return q3

def rotate_quat(quat, vect):
    """
    Rotate a vector with the rotation defined by a quaternion.
    """
    # Transfrom vect into an quaternion 
    vect = np.append([0],vect)
    # Normalize it
    norm_vect = np.linalg.norm(vect)
    vect = vect/norm_vect
    # Computes the conjugate of quat
    quat_ = np.append(quat[0],-quat[1:])
    # The result is given by: quat * vect * quat_
    res = mult_quat(quat, mult_quat(vect,quat_)) * norm_vect
    return res[1:]

v = [3, 5, 0]
axis = [4, 4, 1]
theta = 1.2 

print(rotate_quat(angle_axis_quat(theta, axis), v))
# [2.74911638 4.77180932 1.91629719]

How to make an HTTP get request with parameters

You can also pass value directly via URL.

If you want to call method public static void calling(string name){....}

then you should call usingHttpWebRequest webrequest = (HttpWebRequest)WebRequest.Create("http://localhost:****/Report/calling?name=Priya); webrequest.Method = "GET"; webrequest.ContentType = "application/text";

Just make sure you are using ?Object = value in URL

scroll image with continuous scrolling using marquee tag

You cannot scroll images continuously using the HTML marquee tag - it must have JavaScript added for the continuous scrolling functionality.

There is a JavaScript plugin called crawler.js available on the dynamic drive forum for achieving this functionality. This plugin was created by John Davenport Scheuer and has been modified over time to suit new browsers.

I have also implemented this plugin into my blog to document all the steps to use this plugin. Here is the sample code:

<head>
    <script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>
    <script src="assets/js/crawler.js" type="text/javascript" ></script>
</head>

<div id="mycrawler2" style="margin-top: -3px; " class="productswesupport">
    <img src="assets/images/products/ie.png" />
    <img src="assets/images/products/browser.png" />
    <img src="assets/images/products/chrome.png" />
    <img src="assets/images/products/safari.png" />
</div>

Here is the plugin configration:

marqueeInit({
    uniqueid: 'mycrawler2',
    style: {
    },
    inc: 5, //speed - pixel increment for each iteration of this marquee's movement
    mouse: 'cursor driven', //mouseover behavior ('pause' 'cursor driven' or false)
    moveatleast: 2,
    neutral: 150,
    savedirection: true,
    random: true
});

Getting "net::ERR_BLOCKED_BY_CLIENT" error on some AJAX calls

I find a case is if your url contains the key word banner, it will blocked too.

How do you force a makefile to rebuild a target

Someone else suggested .PHONY which is definitely correct. .PHONY should be used for any rule for which a date comparison between the input and the output is invalid. Since you don't have any targets of the form output: input you should use .PHONY for ALL of them!

All that said, you probably should define some variables at the top of your makefile for the various filenames, and define real make rules that have both input and output sections so you can use the benefits of make, namely that you'll only actually compile things that are necessary to copmile!

Edit: added example. Untested, but this is how you do .PHONY

.PHONY: clean    
clean:
    $(clean)

How can I regenerate ios folder in React Native project?

Remove the ios folder first

 react-native eject 
 cd ios/ 
 pod init 
 pod install 
 cd .. 
 react-native link 
 cd ios 
 open *.xcworkspace/

How to fix warning from date() in PHP"

This just happen to me because in the php.ini the date.timezone was not set!

;date.timezone=Europe/Berlin

Using the php date() function triggered that warning.

What is the difference between varchar and varchar2 in Oracle?

Currently, they are the same. but previously

Somewhere on the net, I read that,

VARCHAR is reserved by Oracle to support distinction between NULL and empty string in future, as ANSI standard prescribes.

VARCHAR2 does not distinguish between a NULL and empty string, and never will.

Also,

Emp_name varchar(10) - if you enter value less than 10 digits then remaining space cannot be deleted. it used total of 10 spaces.

Emp_name varchar2(10) - if you enter value less than 10 digits then remaining space is automatically deleted

How to Install pip for python 3.7 on Ubuntu 18?

Combining the answers from @mpenkon and @dangel, this is what worked for me:

sudo apt install python3-pip
python3.7 -m pip install pip

Step #1 is required (assuming you don't already have pip for python3) for step #2 to work. It uses pip for Python3.6 to install pip for Python 3.7 apparently.

What is the difference between DSA and RSA?

Referring, https://web.archive.org/web/20140212143556/http://courses.cs.tamu.edu:80/pooch/665_spring2008/Australian-sec-2006/less19.html

RSA
RSA encryption and decryption are commutative
hence it may be used directly as a digital signature scheme
given an RSA scheme {(e,R), (d,p,q)}
to sign a message M, compute:
S = M power d (mod R)
to verify a signature, compute:
M = S power e(mod R) = M power e.d(mod R) = M(mod R)

RSA can be used both for encryption and digital signatures, simply by reversing the order in which the exponents are used: the secret exponent (d) to create the signature, the public exponent (e) for anyone to verify the signature. Everything else is identical.

DSA (Digital Signature Algorithm)
DSA is a variant on the ElGamal and Schnorr algorithms. It creates a 320 bit signature, but with 512-1024 bit security again rests on difficulty of computing discrete logarithms has been quite widely accepted.

DSA Key Generation
firstly shared global public key values (p,q,g) are chosen:
choose a large prime p = 2 power L
where L= 512 to 1024 bits and is a multiple of 64
choose q, a 160 bit prime factor of p-1
choose g = h power (p-1)/q
for any h<p-1, h(p-1)/q(mod p)>1
then each user chooses a private key and computes their public key:
choose x<q
compute y = g power x(mod p)

DSA key generation is related to, but somewhat more complex than El Gamal. Mostly because of the use of the secondary 160-bit modulus q used to help speed up calculations and reduce the size of the resulting signature.

DSA Signature Creation and Verification

to sign a message M
generate random signature key k, k<q
compute
r = (g power k(mod p))(mod q)
s = k-1.SHA(M)+ x.r (mod q)
send signature (r,s) with message

to verify a signature, compute:
w = s-1(mod q)
u1= (SHA(M).w)(mod q)
u2= r.w(mod q)
v = (g power u1.y power u2(mod p))(mod q)
if v=r then the signature is verified

Signature creation is again similar to ElGamal with the use of a per message temporary signature key k, but doing calc first mod p, then mod q to reduce the size of the result. Note that the use of the hash function SHA is explicit here. Verification also consists of comparing two computations, again being a bit more complex than, but related to El Gamal.
Note that nearly all the calculations are mod q, and hence are much faster.
But, In contrast to RSA, DSA can be used only for digital signatures

DSA Security
The presence of a subliminal channel exists in many schemes (any that need a random number to be chosen), not just DSA. It emphasises the need for "system security", not just a good algorithm.

Is it correct to use DIV inside FORM?

Absolutely not! It will render, but it will not validate. Use a label.

It is not correct. It is not accessible. You see it on some websites because some developers are just lazy. When I am hiring developers, this is one of the first things I check for in candidates work. Forms are nasty, but take the time and learn to do them properly

C++ display stack trace on exception

I have a similar problem, and though I like portability, I only need gcc support. In gcc, execinfo.h and the backtrace calls are available. To demangle the function names, Mr. Bingmann has a nice piece of code. To dump a backtrace on an exception, I create an exception that prints the backtrace in the constructor. If I were expecting this to work with an exception thrown in a library, it might require rebuilding/linking so that the backtracing exception is used.

/******************************************
#Makefile with flags for printing backtrace with function names
# compile with symbols for backtrace
CXXFLAGS=-g
# add symbols to dynamic symbol table for backtrace
LDFLAGS=-rdynamic
turducken: turducken.cc
******************************************/

#include <cstdio>
#include <stdexcept>
#include <execinfo.h>
#include "stacktrace.h" /* https://panthema.net/2008/0901-stacktrace-demangled/ */

// simple exception that prints backtrace when constructed
class btoverflow_error: public std::overflow_error
{
    public:
    btoverflow_error( const std::string& arg ) :
        std::overflow_error( arg )
    {
        print_stacktrace();
    };
};


void chicken(void)
{
    throw btoverflow_error( "too big" );
}

void duck(void)
{
    chicken();
}

void turkey(void)
{
    duck();
}

int main( int argc, char *argv[])
{
    try
    {
        turkey();
    }
    catch( btoverflow_error e)
    {
        printf( "caught exception: %s\n", e.what() );
    }
}

Compiling and running this with gcc 4.8.4 yields a backtrace with nicely unmangled C++ function names:

stack trace:
 ./turducken : btoverflow_error::btoverflow_error(std::string const&)+0x43
 ./turducken : chicken()+0x48
 ./turducken : duck()+0x9
 ./turducken : turkey()+0x9
 ./turducken : main()+0x15
 /lib/x86_64-linux-gnu/libc.so.6 : __libc_start_main()+0xf5
 ./turducken() [0x401629]

ExecuteNonQuery doesn't return results

You use EXECUTENONQUERY() for INSERT,UPDATE and DELETE.

But for SELECT you must use EXECUTEREADER().........

How to keep footer at bottom of screen

HTML

<div id="footer"></div>

CSS

#footer {
   position:absolute;
   bottom:0;
   width:100%;
   height:100px;   
   background:blue;//optional
}

How to correctly dismiss a DialogFragment?

There are references to the official docs (DialogFragment Reference) in other answers, but no mention of the example given there:

void showDialog() {
    mStackLevel++;

    // DialogFragment.show() will take care of adding the fragment
    // in a transaction.  We also want to remove any currently showing
    // dialog, so make our own transaction and take care of that here.
    FragmentTransaction ft = getFragmentManager().beginTransaction();
    Fragment prev = getFragmentManager().findFragmentByTag("dialog");
    if (prev != null) {
        ft.remove(prev);
    }
    ft.addToBackStack(null);

    // Create and show the dialog.
    DialogFragment newFragment = MyDialogFragment.newInstance(mStackLevel);
    newFragment.show(ft, "dialog");
}

This removes any currently shown dialog, creates a new DialogFragment with an argument, and shows it as a new state on the back stack. When the transaction is popped, the current DialogFragment and its Dialog will be destroyed, and the previous one (if any) re-shown. Note that in this case DialogFragment will take care of popping the transaction of the Dialog is dismissed separately from it.

For my needs I changed it to:

FragmentManager manager = getSupportFragmentManager();
Fragment prev = manager.findFragmentByTag(TAG);
if (prev != null) {
    manager.beginTransaction().remove(prev).commit();
}

MyDialogFragment fragment = new MyDialogFragment();
fragment.show(manager, TAG);

Sending Arguments To Background Worker?

You should always try to use a composite object with concrete types (using composite design pattern) rather than a list of object types. Who would remember what the heck each of those objects is? Think about maintenance of your code later on... Instead, try something like this:

Public (Class or Structure) MyPerson
                public string FirstName { get; set; }
                public string LastName { get; set; }
                public string Address { get; set; }
                public int ZipCode { get; set; }
End Class

And then:

Dim person as new MyPerson With { .FirstName = “Joe”,
                                  .LastName = "Smith”,
                                  ...
                                 }
backgroundWorker1.RunWorkerAsync(person)

and then:

private void backgroundWorker1_DoWork (object sender, DoWorkEventArgs e)
{
        MyPerson person = e.Argument as MyPerson
        string firstname = person.FirstName;
        string lastname = person.LastName;
        int zipcode = person.ZipCode;                                 
}

How does inline Javascript (in HTML) work?

What the browser does when you've got

<a onclick="alert('Hi');" ... >

is to set the actual value of "onclick" to something effectively like:

new Function("event", "alert('Hi');");

That is, it creates a function that expects an "event" parameter. (Well, IE doesn't; it's more like a plain simple anonymous function.)

Setting background images in JFrame

Try this :

import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;


public class Test {

    public static void main(String[] args) {
        JFrame f = new JFrame();
        try {
            f.setContentPane(new JLabel(new ImageIcon(ImageIO.read(new File("test.jpg")))));
        } catch (IOException e) {
            e.printStackTrace();
        }
        f.pack();
        f.setVisible(true);
    }

}

By the way, this will result in the content pane not being a container. If you want to add things to it you have to subclass a JPanel and override the paintComponent method.

How do I register a .NET DLL file in the GAC?

I tried just about everything in the comments and it didn't work. So I did gacutil /i "path to my dll" from Powershell and it worked.

Also remember the trick of pressing Shift when you right-click on a file in Windows Explorer to get the option of Copy path.

How to delete migration files in Rails 3

Sometimes I found myself deleting the migration file and then deleting the corresponding entry on the table schema_migrations from the database. Not pretty but it works.

Insert null/empty value in sql datetime column by default

Ozi, when you create a new datetime object as in datetime foo = new datetime(); foo is constructed with the time datetime.minvalue() in building a parameterized query, you could check to see if the values entered are equal to datetime.minvalue()

-Just a side thought. seems you have things working.

How can I handle the warning of file_get_contents() function in PHP?

One alternative is to suppress the error and also throw an exception which you can catch later. This is especially useful if there are multiple calls to file_get_contents() in your code, since you don't need to suppress and handle all of them manually. Instead, several calls can be made to this function in a single try/catch block.

// Returns the contents of a file
function file_contents($path) {
    $str = @file_get_contents($path);
    if ($str === FALSE) {
        throw new Exception("Cannot access '$path' to read contents.");
    } else {
        return $str;
    }
}

// Example
try {
    file_contents("a");
    file_contents("b");
    file_contents("c");
} catch (Exception $e) {
    // Deal with it.
    echo "Error: " , $e->getMessage();
}

What, exactly, is needed for "margin: 0 auto;" to work?

Here is my Suggestion:

First: 
      1. Add display: block or table
      2. Add position: relative
      3. Add width:(percentage also works fine)
Second: 
      if above trick not works then you have to add float:none;

Why is this rsync connection unexpectedly closed on Windows?

This error message probably means that you either mistyped the server name or forgot to start an ssh server at server. Make absolutely certain that an ssh server is running on the server at port 22, and that it's not firewalled. You can test that with ssh user@server.

How to use random in BATCH script?

And just to be completely random for those who don't always want a black screen.

@(IF not "%1" == "max" (start /MAX cmd /Q /C %0 max&X)ELSE set A=0&set C=1&set V=A&wmic process where name="cmd.exe" CALL setpriority "REALTIME">NUL)&CLS
:Y
(IF %A% EQU 10 set A=A)&(IF %A% EQU 11 set A=B)&(IF %A% EQU 12 set A=C)&(IF %A% EQU 13 set A=D)&(IF %A% EQU 14 set A=E)&(IF %A% EQU 15 set A=F)
(IF %V% EQU 10 set V=A)&(IF %V% EQU 11 set V=B)&(IF %V% EQU 12 set V=C)&(IF %V% EQU 13 set V=D)&(IF %V% EQU 14 set V=E)&(IF %V% EQU 15 set V=F)
(IF %A% EQU %V% set A=0)
title %A%%V%%random%6%random%%random%%random%%random%9%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%&color %A%%V%&ECHO %random%%C%%random%%random%%random%%random%6%random%9%random%%random%%random%%random%%random%%random%%random%%random%%random%&(IF %C% EQU 46 (TIMEOUT /T 1 /NOBREAK>nul&set C=1&CLS&SET /A A=%random% %%15 +1&SET /A V=%random% %%15 +1)ELSE set /A C=%C%+1)&goto Y

This will change screen color also both are random.

Invalid argument supplied for foreach()

I usually use a construct similar to this:

/**
 * Determine if a variable is iterable. i.e. can be used to loop over.
 *
 * @return bool
 */
function is_iterable($var)
{
    return $var !== null 
        && (is_array($var) 
            || $var instanceof Traversable 
            || $var instanceof Iterator 
            || $var instanceof IteratorAggregate
            );
}

$values = get_values();

if (is_iterable($values))
{
    foreach ($values as $value)
    {
        // do stuff...
    }
}

Note that this particular version is not tested, its typed directly into SO from memory.

Edit: added Traversable check

flow 2 columns of text automatically with CSS

Maybe a slightly tighter version? My use case is outputting college majors given a json array of majors (data).

var count_data      = data.length;

$.each( data, function( index ){
    var column = ( index < count_data/2 ) ? 1 : 2;
    $("#column"+column).append(this.name+'<br/>');
});

<div id="majors_view" class="span12 pull-left">

  <div class="row-fluid">
    <div class="span5" id="column1"> </div>
    <div class="span5 offset1" id="column2"> </div>
  </div>

</div>

CSS image resize percentage of itself?

Actually most of the answers here doesn't really scale the image to the width of itself.

We need to have a width and height of auto on the img element itself so we can start with it's original size.

After that a container element can scale the image for us.

Simple HTML example:

<div style="position: relative;">
    <figure>
       <img src="[email protected]" />
    </figure>
</div>

And here are the CSS rules. I use an absolute container in this case:

figure {
    position: absolute;
    left: 0;
    top: 0;
    -webkit-transform: scale(0.5); 
    -moz-transform: scale(0.5);
    -ms-transform: scale(0.5); 
    -o-transform: scale(0.5);
    transform: scale(0.5);
    transform-origin: left;
} 

figure img {
    width: auto;
    height: auto;
}

You could tweak the image positioning with rules like transform: translate(0%, -50%);.

How do I create a GUI for a windows application using C++?

For such a simple application even MFC would be overkill. If don't want to introduce another dependency just do it in plain vanilla Win32. It will be easier for you if you have never used MFC.

Check out the classic "Programming Windows" by Charles Petzold or some online tutorial (e.g. http://www.winprog.org/tutorial/) and you are ready to go.

How do I add a library path in cmake?

might fail working with link_directories, then add each static library like following:

target_link_libraries(foo /path_to_static_library/libbar.a)

How to find Google's IP address?

I'm keeping the following list updated for a couple of years now:

1.0.0.0/24
1.1.1.0/24
1.2.3.0/24
8.6.48.0/21
8.8.8.0/24
8.35.192.0/21
8.35.200.0/21
8.34.216.0/21
8.34.208.0/21
23.236.48.0/20
23.251.128.0/19
63.161.156.0/24
63.166.17.128/25
64.9.224.0/19
64.18.0.0/20
64.233.160.0/19
64.233.171.0/24
65.167.144.64/28
65.170.13.0/28
65.171.1.144/28
66.102.0.0/20
66.102.14.0/24
66.249.64.0/19
66.249.92.0/24
66.249.86.0/23
70.32.128.0/19
72.14.192.0/18
74.125.0.0/16
89.207.224.0/21
104.154.0.0/15
104.132.0.0/14
107.167.160.0/19
107.178.192.0/18
108.59.80.0/20
108.170.192.0/18
108.177.0.0/17
130.211.0.0/16
142.250.0.0/15
144.188.128.0/24
146.148.0.0/17
162.216.148.0/22
162.222.176.0/21
172.253.0.0/16
173.194.0.0/16
173.255.112.0/20
192.158.28.0/22
193.142.125.0/28
199.192.112.0/22
199.223.232.0/21
206.160.135.240/24
207.126.144.0/20
208.21.209.0/24
209.85.128.0/17
216.239.32.0/19

IntelliJ can't recognize JavaFX 11 with OpenJDK 11

As mentioned in the comments, the Starting Guide is the place to start with Java 11 and JavaFX 11.

The key to work as you did before Java 11 is to understand that:

JavaFX 11 is not part of the JDK anymore
You can get it in different flavors, either as an SDK or as regular dependencies (maven/gradle).
You will need to include it to the module path of your project, even if your project is not modular.

JavaFX project

If you create a regular JavaFX default project in IntelliJ (without Maven or Gradle) I'd suggest you download the SDK from here. Note that there are jmods as well, but for a non modular project the SDK is preferred.

These are the easy steps to run the default project:

Create a JavaFX project
Set JDK 11 (point to your local Java 11 version)
Add the JavaFX 11 SDK as a library. The URL could be something like /Users/<user>/Downloads/javafx-sdk-11/lib/. Once you do this you will notice that the JavaFX classes are now recognized in the editor.

Before you run the default project, you just need to add these to the VM options:

--module-path /Users/<user>/Downloads/javafx-sdk-11/lib --add-modules=javafx.controls,javafx.fxml
Run

Maven

If you use Maven to build your project, follow these steps:

Create a Maven project with JavaFX archetype
Set JDK 11 (point to your local Java 11 version)

Add the JavaFX 11 dependencies.

<dependencies>
    <dependency>
        <groupId>org.openjfx</groupId>
        <artifactId>javafx-controls</artifactId>
        <version>11</version>
    </dependency>
    <dependency>
        <groupId>org.openjfx</groupId>
        <artifactId>javafx-fxml</artifactId>
        <version>11</version>
    </dependency>
</dependencies>

Once you do this you will notice that the JavaFX classes are now recognized in the editor.

You will notice that Maven manages the required dependencies for you: it will add javafx.base and javafx.graphics for javafx.controls, but most important, it will add the required classifier based on your platform. In my case, Mac.

This is why your jars org.openjfx:javafx-controls:11 are empty, because there are three possible classifiers (windows, linux and mac platforms), that contain all the classes and the native implementation.

In case you still want to go to your .m2 repo and take the dependencies from there manually, make sure you pick the right one (for instance .m2/repository/org/openjfx/javafx-controls/11/javafx-controls-11-mac.jar)

Replace default maven plugins with those from here.
Run mvn compile javafx:run, and it should work.

Similar works as well for Gradle projects, as explained in detail here.

EDIT

The mentioned Getting Started guide contains updated documentation and sample projects for IntelliJ:

JavaFX 11 without Maven/Gradle, see non-modular sample or modular sample projects.
JavaFX 11 with Maven, see non-modular sample or modular sample projects.
JavaFX 11 with Gradle, see non-modular sample or modular sample projects.

How to get the seconds since epoch from the time + date output of gmtime()?

There are two ways, depending on your original timestamp:

mktime() and timegm()

http://docs.python.org/library/time.html

'uint32_t' does not name a type

just navigate to /usr/include/x86_64-linux-gnu/bits open stdint-uintn.h and add these lines

typedef __uint8_t uint8_t;
typedef __uint16_t uint16_t;
typedef __uint32_t uint32_t;
typedef __uint64_t uint64_t;

again open stdint-intn.h and add

typedef __int8_t int8_t;
typedef __int16_t int16_t;
typedef __int32_t int32_t;
typedef __int64_t int64_t;

note these lines are already present just copy and add the missing lines cheerss..

How to load all modules in a folder?

Anurag Uniyal answer with suggested improvements!

#!/usr/bin/python
# -*- encoding: utf-8 -*-

import os
import glob

all_list = list()
for f in glob.glob(os.path.dirname(__file__)+"/*.py"):
    if os.path.isfile(f) and not os.path.basename(f).startswith('_'):
        all_list.append(os.path.basename(f)[:-3])

__all__ = all_list

Adding images or videos to iPhone Simulator

I just needed some random images for testing, so this is how I did it.

I have the simplest solution in the world. Just open Safari in the simulator, go to Google images (or your own web or Dropbox URL), view an image, hold down the mouse button for 2 seconds, and you'll see "Save Image" - it will save right into the Photos library. Rinse and repeat.

How to replace multiple patterns at once with sed?

Here is a variation on ooga's answer that works for multiple search and replace pairs without having to check how values might be reused:

sed -i '
s/\bAB\b/________BC________/g
s/\bBC\b/________CD________/g
s/________//g
' path_to_your_files/*.txt

Here is an example:

before:

some text AB some more text "BC" and more text.

after:

some text BC some more text "CD" and more text.

Note that \b denotes word boundaries, which is what prevents the ________ from interfering with the search (I'm using GNU sed 4.2.2 on Ubuntu). If you are not using a word boundary search, then this technique may not work.

Also note that this gives the same results as removing the s/________//g and appending && sed -i 's/________//g' path_to_your_files/*.txt to the end of the command, but doesn't require specifying the path twice.

A general variation on this would be to use \x0 or _\x0_ in place of ________ if you know that no nulls appear in your files, as jthill suggested.

How to create/read/write JSON files in Qt5

An example on how to use that would be great. There is a couple of examples at the Qt forum, but you're right that the official documentation should be expanded.

QJsonDocument on its own indeed doesn't produce anything, you will have to add the data to it. That's done through the QJsonObject, QJsonArray and QJsonValue classes. The top-level item needs to be either an array or an object (because 1 is not a valid json document, while {foo: 1} is.)

Remove part of string after "."

We can pretend they are filenames and remove extensions:

tools::file_path_sans_ext(a)
# [1] "NM_020506"    "NM_020519"    "NM_001030297" "NM_010281"    "NM_011419"    "NM_053155"

Javascript "Cannot read property 'length' of undefined" when checking a variable's length

Why?

You asked why it happens, let's see:

The official language specificaion dictates a call to the internal [[GetValue]] method. Your .attr returns undefined and you're trying to access its length.

If Type(V) is not Reference, return V.

This is true, since undefined is not a reference (alongside null, number, string and boolean)

Let base be the result of calling GetBase(V).

This gets the undefined part of myVar.length .

If IsUnresolvableReference(V), throw a ReferenceError exception.

This is not true, since it is resolvable and it resolves to undefined.

If IsPropertyReference(V), then

This happens since it's a property reference with the . syntax.

Now it tries to convert undefined to a function which results in a TypeError.

Page vs Window in WPF?

Pages are intended for use in Navigation applications (usually with Back and Forward buttons, e.g. Internet Explorer). Pages must be hosted in a NavigationWindow or a Frame

Windows are just normal WPF application Windows, but can host Pages via a Frame container

Insert at first position of a list in Python

Use insert:

In [1]: ls = [1,2,3]

In [2]: ls.insert(0, "new")

In [3]: ls
Out[3]: ['new', 1, 2, 3]

Error: "dictionary update sequence element #0 has length 1; 2 is required" on Django 1.4

You are sending one parameter incorrectly; it should be a dictionary object:

Wrong: func(a=r)
Correct: func(a={'x':y})

How to pass 2D array (matrix) in a function in C?

2D array:

int sum(int array[][COLS], int rows)
{

}

3D array:

int sum(int array[][B][C], int A)
{

}

4D array:

int sum(int array[][B][C][D], int A)
{

}

and nD array:

int sum(int ar[][B][C][D][E][F].....[N], int A)
{

}

How do I verify/check/test/validate my SSH passphrase?

Use "ssh-keygen -p". You can add "-f "

It will prompt you for the old password. If the password is correct, it will prompt to enter a new password. If the old password is incorrect, you will get "Failed to load key <...>".

java.lang.ClassNotFoundException: org.apache.log4j.Level

You need to download log4j and add in your classpath.

How to purge tomcat's cache when deploying a new .war file? Is there a config setting?

Tomcat also creates a ROOT directory at the same level as work/. ROOT/ also caches the old stuff. delete ROOT along with Catalina directory in work.

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

Note:- below is the illustration of map and flatmap function, otherwise Optional is primarily designed to be used as a return type only.

As you already may know Optional is a kind of container which may or may not contain a single object, so it can be used wherever you anticipate a null value(You may never see NPE if use Optional properly). For example if you have a method which expects a person object which may be nullable you may want to write the method something like this:

void doSome(Optional<Person> person){
  /*and here you want to retrieve some property phone out of person
    you may write something like this:
  */
  Optional<String> phone = person.map((p)->p.getPhone());
  phone.ifPresent((ph)->dial(ph));
}
class Person{
  private String phone;
  //setter, getters
}

Here you have returned a String type which is automatically wrapped in an Optional type.

If person class looked like this, i.e. phone is also Optional

class Person{
  private Optional<String> phone;
  //setter,getter
}

In this case invoking map function will wrap the returned value in Optional and yield something like:

Optional<Optional<String>> 
//And you may want Optional<String> instead, here comes flatMap

void doSome(Optional<Person> person){
  Optional<String> phone = person.flatMap((p)->p.getPhone());
  phone.ifPresent((ph)->dial(ph));
}

PS; Never call get method (if you need to) on an Optional without checking it with isPresent() unless you can't live without NullPointerExceptions.

How to perform runtime type checking in Dart?

There are two operators for type testing: E is T tests for E an instance of type T while E is! T tests for E not an instance of type T.

Note that E is Object is always true, and null is T is always false unless T===Object.

How to remove white space characters from a string in SQL Server

Remove new line characters with SQL column data

Update a set  a.CityName=Rtrim(Ltrim(REPLACE(REPLACE(a.CityName,CHAR(10),' '),CHAR(13),' ')))
,a.postalZone=Rtrim(Ltrim(REPLACE(REPLACE(a.postalZone,CHAR(10),' '),CHAR(13),' ')))  
From tAddress a 
inner Join  tEmployees p  on a.AddressId =p.addressId 
Where p.MigratedID is not null and p.AddressId is not null AND
(REPLACE(REPLACE(a.postalZone,CHAR(10),'Y'),CHAR(13),'X') Like 'Y%' OR REPLACE(REPLACE(a.CityName,CHAR(10),'Y'),CHAR(13),'X') Like 'Y%')

Sort hash by key, return hash in Ruby

In Ruby 2.1 it is simple:

h.sort.to_h

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

function remote_file_exists($url){
   return(bool)preg_match('~HTTP/1\.\d\s+200\s+OK~', @current(get_headers($url)));
}  
$ff = "http://www.emeditor.com/pub/emed32_11.0.5.exe";
    if(remote_file_exists($ff)){
        echo "file exist!";
    }
    else{
        echo "file not exist!!!";
    }

Angular 4: InvalidPipeArgument: '[object Object]' for pipe 'AsyncPipe'

I found another solution to get the data. according to the documentation Please check documentation link

In service file add following.

import { Injectable } from '@angular/core';
import { AngularFireDatabase } from 'angularfire2/database';

@Injectable()
export class MoviesService {

  constructor(private db: AngularFireDatabase) {}
  getMovies() {
    this.db.list('/movies').valueChanges();
  }
}

In Component add following.

import { Component, OnInit } from '@angular/core';
import { MoviesService } from './movies.service';

@Component({
  selector: 'app-movies',
  templateUrl: './movies.component.html',
  styleUrls: ['./movies.component.css']
})
export class MoviesComponent implements OnInit {
  movies$;

  constructor(private moviesDb: MoviesService) { 
   this.movies$ = moviesDb.getMovies();
 }

In your html file add following.

<li  *ngFor="let m of movies$ | async">{{ m.name }} </li>

How do I get the directory of the PowerShell script I execute?

PowerShell 3 has the $PSScriptRoot automatic variable:

Contains the directory from which a script is being run.

In Windows PowerShell 2.0, this variable is valid only in script modules (.psm1). Beginning in Windows PowerShell 3.0, it is valid in all scripts.

Don't be fooled by the poor wording. PSScriptRoot is the directory of the current file.

In PowerShell 2, you can calculate the value of $PSScriptRoot yourself:

# PowerShell v2
$PSScriptRoot = Split-Path -Parent -Path $MyInvocation.MyCommand.Definition

PHP: Return all dates between two dates in an array

function createDateRangeArray($strDateFrom,$strDateTo)
{
    // takes two dates formatted as YYYY-MM-DD and creates an
    // inclusive array of the dates between the from and to dates.

    // could test validity of dates here but I'm already doing
    // that in the main script

    $aryRange = [];

    $iDateFrom = mktime(1, 0, 0, substr($strDateFrom, 5, 2), substr($strDateFrom, 8, 2), substr($strDateFrom, 0, 4));
    $iDateTo = mktime(1, 0, 0, substr($strDateTo, 5, 2), substr($strDateTo, 8, 2), substr($strDateTo, 0, 4));

    if ($iDateTo >= $iDateFrom) {
        array_push($aryRange, date('Y-m-d', $iDateFrom)); // first entry
        while ($iDateFrom<$iDateTo) {
            $iDateFrom += 86400; // add 24 hours
            array_push($aryRange, date('Y-m-d', $iDateFrom));
        }
    }
    return $aryRange;
}

source: http://boonedocks.net/mike/archives/137-Creating-a-Date-Range-Array-with-PHP.html

Removing highcharts.com credits link

credits : null

also works to disable the credits

Set UILabel line spacing

From Interface Builder:

enter image description here

Programmatically:

SWift 4

Using label extension

extension UILabel {

    func setLineSpacing(lineSpacing: CGFloat = 0.0, lineHeightMultiple: CGFloat = 0.0) {

        guard let labelText = self.text else { return }

        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = lineSpacing
        paragraphStyle.lineHeightMultiple = lineHeightMultiple

        let attributedString:NSMutableAttributedString
        if let labelattributedText = self.attributedText {
            attributedString = NSMutableAttributedString(attributedString: labelattributedText)
        } else {
            attributedString = NSMutableAttributedString(string: labelText)
        }

        // Line spacing attribute
        attributedString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))

        self.attributedText = attributedString
    }
}

Now call extension function

let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"

// Pass value for any one argument - lineSpacing or lineHeightMultiple
label.setLineSpacing(lineSpacing: 2.0) .  // try values 1.0 to 5.0

// or try lineHeightMultiple
//label.setLineSpacing(lineHeightMultiple = 2.0) // try values 0.5 to 2.0

Or using label instance (Just copy & execute this code to see result)

let label = UILabel()
let stringValue = "Set\nUILabel\nline\nspacing"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40

// Line spacing attribute
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: style, range: NSRange(location: 0, length: stringValue.characters.count))

// Character spacing attribute
attrString.addAttribute(NSAttributedStringKey.kern, value: 2, range: NSMakeRange(0, attrString.length))

label.attributedText = attrString

Swift 3

let label = UILabel()
let stringValue = "Set\nUILabel\nline\nspacing"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
attrString.addAttribute(NSParagraphStyleAttributeName, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
label.attributedText = attrString

Pandas split column of lists into multiple columns

Much simpler solution:

pd.DataFrame(df2["teams"].to_list(), columns=['team1', 'team2'])

Yields,

  team1 team2
-------------
0    SF   NYG
1    SF   NYG
2    SF   NYG
3    SF   NYG
4    SF   NYG
5    SF   NYG
6    SF   NYG
7    SF   NYG

If you wanted to split a column of delimited strings rather than lists, you could similarly do:

pd.DataFrame(df["teams"].str.split('<delim>', expand=True).values,
             columns=['team1', 'team2'])

link_to method and click event in Rails

another solution is catching onClick event and for aggregate data to js function you can

.hmtl.erb

<%= link_to "Action", 'javascript:;', class: 'my-class', data: { 'array' => %w(foo bar) } %>

.js

// handle my-class click
$('a.my-class').on('click', function () {
  var link = $(this);
  var array = link.data('array');
});

Copy a table from one database to another in Postgres

I was using DataGrip (By Intellij Idea). and it was very easy copying data from one table (in a different database to another).

First, make sure you are connected with both DataSources in Data Grip.

Select Source Table and press F5 or (Right-click -> Select Copy Table to.)

This will show you a list of all tables (you can also search using a table name in the popup window). Just select your target and press OK.

DataGrip will handle everything else for you.

html5 input for money/currency

More easy and beautiful if you has vue.js v-money-spinner :)

AngularJs event to call after content is loaded

you can call javascript version of onload event in angular js. this ng-load event can be applied to any dom element like div, span, body, iframe, img etc. following is the link to add ng-load in your existing project.

download ng-load for angular js

Following is example for iframe, once it is loaded testCallbackFunction will be called in controller

EXAMPLE

    // include the `ngLoad` module
    var app = angular.module('myApp', ['ngLoad']);
    app.controller('myCtrl', function($scope) {
        $scope.testCallbackFunction = function() {
          //TODO : Things to do once Element is loaded
        };

    });

HTML

  <div ng-app='myApp' ng-controller='myCtrl'> 
      <iframe src="test.html" ng-load callback="testCallbackFunction()">  
  </div>

Find files in created between a date range

If you use GNU find, since version 4.3.3 you can do:

find -newerct "1 Aug 2013" ! -newerct "1 Sep 2013" -ls

It will accept any date string accepted by GNU date -d.

You can change the c in -newerct to any of a, B, c, or m for looking at atime/birth/ctime/mtime.

Another example - list files modified between 17:30 and 22:00 on Nov 6 2017:

find -newermt "2017-11-06 17:30:00" ! -newermt "2017-11-06 22:00:00" -ls

Full details from man find:

   -newerXY reference
          Compares the timestamp of the current file with reference.  The reference argument is normally the name of a file (and one of its timestamps  is  used
          for  the  comparison)  but  it may also be a string describing an absolute time.  X and Y are placeholders for other letters, and these letters select
          which time belonging to how reference is used for the comparison.

          a   The access time of the file reference
          B   The birth time of the file reference
          c   The inode status change time of reference
          m   The modification time of the file reference
          t   reference is interpreted directly as a time

          Some combinations are invalid; for example, it is invalid for X to be t.  Some combinations are not implemented on all systems; for example B  is  not
          supported on all systems.  If an invalid or unsupported combination of XY is specified, a fatal error results.  Time specifications are interpreted as
          for the argument to the -d option of GNU date.  If you try to use the birth time of a reference file, and the birth time cannot be determined, a fatal
          error  message  results.   If  you  specify a test which refers to the birth time of files being examined, this test will fail for any files where the
          birth time is unknown.

Find the least number of coins required that can make any change from 1 to 99 cents

Assuming you're talking about US currency, you would want a Greedy Algorithm: http://en.wikipedia.org/wiki/Greedy_algorithm

In essence, you try all denominations from highest-to-lowest, taking as many coins as posible from each one until you've got nothing left.

For the general case see http://en.wikipedia.org/wiki/Change-making_problem, because you would want to use dynamic programming or linear programming to find the answer for arbitrary denominations where a greedy algorithm wouldn't work.

How to create an array for JSON using PHP?

Simple: Just create a (nested) PHP array and call json_encode on it. Numeric arrays translate into JSON lists ([]), associative arrays and PHP objects translate into objects ({}). Example:

$a = array(
        array('foo' => 'bar'),
        array('foo' => 'baz'));
$json = json_encode($a);

Gives you:

[{"foo":"bar"},{"foo":"baz"}]

Hive: Filtering Data between Specified Dates when Date is a String

Just like SQL, Hive supports BETWEEN operator for more concise statement:

SELECT *
  FROM your_table
  WHERE your_date_column BETWEEN '2010-09-01' AND '2013-08-31';

Angular 5 - Copy to clipboard

You can achieve this using Angular modules:

navigator.clipboard.writeText('your text').then().catch(e => console.error(e));

Disable cache for some images

I was just looking for a solution to this, and the answers above didn't work in my case (and I have insufficient reputation to comment on them). It turns out that, at least for my use-case and the browser I was using (Chrome on OSX), the only thing that seemed to prevent caching was:

Cache-Control = 'no-store'

For completeness i'm now using all 3 of 'no-cache, no-store, must-revalidate'

So in my case (serving dynamically generated images out of Flask in Python), I had to do the following to hopefully work in as many browsers as possible...

def make_uncached_response(inFile):
    response = make_response(inFile)
    response.headers['Pragma-Directive'] = 'no-cache'
    response.headers['Cache-Directive'] = 'no-cache'
    response.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
    response.headers['Pragma'] = 'no-cache'
    response.headers['Expires'] = '0'
    return response

How do I clone a github project to run locally?

To clone a repository and place it in a specified directory use "git clone [url] [directory]". For example

git clone https://github.com/ryanb/railscasts-episodes.git Rails

will create a directory named "Rails" and place it in the new directory. Click here for more information.

Java generics: multiple generic parameters?

Even more, you can inherit generics :)

@SuppressWarnings("unchecked")
public <T extends Something<E>, E extends Enum<E> & SomethingAware> T getSomething(Class<T> clazz) {
        return (T) somethingHolderMap.get(clazz);
    }

What does Ruby have that Python doesn't, and vice versa?

Some others from:

http://www.ruby-lang.org/en/documentation/ruby-from-other-languages/to-ruby-from-python/

(If I have misintrepreted anything or any of these have changed on the Ruby side since that page was updated, someone feel free to edit...)

Strings are mutable in Ruby, not in Python (where new strings are created by "changes").

Ruby has some enforced case conventions, Python does not.

Python has both lists and tuples (immutable lists). Ruby has arrays corresponding to Python lists, but no immutable variant of them.

In Python, you can directly access object attributes. In Ruby, it's always via methods.

In Ruby, parentheses for method calls are usually optional, but not in Python.

Ruby has public, private, and protected to enforce access, instead of Python’s convention of using underscores and name mangling.

Python has multiple inheritance. Ruby has "mixins."

And another very relevant link:

http://c2.com/cgi/wiki?PythonVsRuby

Which, in particular, links to another good one by Alex Martelli, who's been also posting a lot of great stuff here on SO:

http://groups.google.com/group/comp.lang.python/msg/028422d707512283

Getting mouse position in c#

To answer your specific example:

// your example
Location.X = Cursor.Position.X;
Location.Y = Cursor.Position.Y;

// sample code
Console.WriteLine("x: " + Cursor.Position.X + " y: " + Cursor.Position.Y);

Don't forget to add using System.Windows.Forms;, and adding the reference to it (right click on references > add reference > .NET tab > Systems.Windows.Forms > ok)

CFLAGS vs CPPFLAGS

The CPPFLAGS macro is the one to use to specify #include directories.

Both CPPFLAGS and CFLAGS work in your case because the make(1) rule combines both preprocessing and compiling in one command (so both macros are used in the command).

You don't need to specify . as an include-directory if you use the form #include "...". You also don't need to specify the standard compiler include directory. You do need to specify all other include-directories.

Repair all tables in one go

If corrupted tables remain after

mysqlcheck -A --auto-repair

try

mysqlcheck -A --auto-repair --use-frm

ps1 cannot be loaded because running scripts is disabled on this system

The following three steps are used to fix Running Scripts is disabled on this System error

Step1 : To fix this kind of problem, we have to start power shell in administrator mode.

Step2 : Type the following command set-ExecutionPolicy RemoteSigned Step3: Press Y for your Confirmation.

Visit the following for more information https://youtu.be/J_596H-sWsk

Altering column size in SQL Server

For Oracle For Database:

ALTER TABLE table_name MODIFY column_name VARCHAR2(255 CHAR);

What is a good game engine that uses Lua?

A few more:

How to set value in @Html.TextBoxFor in Razor syntax?

I tried replacing value with Value and it worked out. It has set the value in input tag now.

Java: Detect duplicates in ArrayList?

Simply put: 1) make sure all items are comparable 2) sort the array 2) iterate over the array and find duplicates

What is Common Gateway Interface (CGI)?

CGI is an interface which tells the webserver how to pass data to and from an application. More specifically, it describes how request information is passed in environment variables (such as request type, remote IP address), how the request body is passed in via standard input, and how the response is passed out via standard output. You can refer to the CGI specification for details.

To use your image:

user (client) request for page ---> webserver ---[CGI]----> Server side Program ---> MySQL Server.

Most if not all, webservers can be configured to execute a program as a 'CGI'. This means that the webserver, upon receiving a request, will forward the data to a specific program, setting some environment variables and marshalling the parameters via standard input and standard output so the program can know where and what to look for.

The main benefit is that you can run ANY executable code from the web, given that both the webserver and the program know how CGI works. That's why you could write web programs in C or Bash with a regular CGI-enabled webserver. That, and that most programming environments can easily use standard input, standard output and environment variables.

In your case you most likely used another, specific for PHP, means of communication between your scripts and the webserver, this, as you well mention in your question, is an embedded interpreter called mod_php.

So, answering your questions:

What exactly is CGI?

See above.

Whats the big deal with /cgi-bin/*.cgi? Whats up with this? I don't know what is this cgi-bin directory on the server for. I don't know why they have *.cgi extensions.

That's the traditional place for cgi programs, many webservers come with this directory pre configured to execute all binaries there as CGI programs. The .cgi extension denotes an executable that is expected to work through the CGI.

Why does Perl always comes in the way. CGI & Perl (language). I also don't know whats up with these two. Almost all the time I keep hearing these two in combination "CGI & Perl". This book is another great example CGI Programming with Perl Why not "CGI Programming with PHP/JSP/ASP". I never saw such things.

Because Perl is ancient (older than PHP, JSP and ASP which all came to being when CGI was already old, Perl existed when CGI was new) and became fairly famous for being a very good language to serve dynamic webpages via the CGI. Nowadays there are other alternatives to run Perl in a webserver, mainly mod_perl.

CGI Programming in C this confuses me a lot. in C?? Seriously?? I don't know what to say. I"m just confused. "in C"?? This changes everything. Program needs to be compiled and executed. This entirely changes my view of web programming. When do I compile? How does the program gets executed (because it will be a machine code, so it must execute as a independent process). How does it communicate with the web server? IPC? and interfacing with all the servers (in my example MATLAB & MySQL) using socket programming? I'm lost!!

You compile the executable once, the webserver executes the program and passes the data in the request to the program and outputs the received response. CGI specifies that one program instance will be launched per each request. This is why CGI is inefficient and kind of obsolete nowadays.

They say that CGI is deprecated. Its no more in use. Is it so? What is its latest update?

CGI is still used when performance is not paramount and a simple means of executing code is required. It is inefficient for the previously stated reasons and there are more modern means of executing any program in a web enviroment. Currently the most famous is FastCGI.

Return a "NULL" object if search result not found

In C++, references can't be null. If you want to optionally return null if nothing is found, you need to return a pointer, not a reference:

Attr *getAttribute(const string& attribute_name) const {
   //search collection
   //if found at i
        return &attributes[i];
   //if not found
        return nullptr;
}

Otherwise, if you insist on returning by reference, then you should throw an exception if the attribute isn't found.

(By the way, I'm a little worried about your method being const and returning a non-const attribute. For philosophical reasons, I'd suggest returning const Attr *. If you also may want to modify this attribute, you can overload with a non-const method returning a non-const attribute as well.)

android.view.InflateException: Binary XML file: Error inflating class fragment

I couldn't solve my problem using provided answers. Finally I changed this:

<fragment
android:id="@+id/fragment_food_image_gallery"
android:name="ir.smartrestaurant.ui.fragment.ImageGalleryFragment"
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout="@layout/fragment_image_gallery"
tools:layout="@layout/fragment_image_gallery" />

to this :

<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="200dp" />

private void showGallery() {
    ImageGalleryFragment fragment = new ImageGalleryFragment()
    getSupportFragmentManager().beginTransaction()
                .replace(R.id.fragment_container, fragment)
                .commit();
    }

and it works.
If you are using it inside fragment, use getChildFragmentManager instead of getSupportFragmentManager.

How do I enable/disable log levels in Android?

https://limxtop.blogspot.com/2019/05/app-log.html

Read this article please, where provides complete implement:

For debug version, all the logs will be output;
For release version, only the logs whose level is above DEBUG (exclude) will be output by default. In the meanwhile, the DEBUG and VERBOSE log can be enable through setprop log.tag.<YOUR_LOG_TAG> <LEVEL> in running time.

Spring @Autowired and @Qualifier

@Autowired to autowire(or search) by-type
@Qualifier to autowire(or search) by-name
Other alternate option for @Qualifier is @Primary

@Component
@Qualifier("beanname")
public class A{}

public class B{

//Constructor
@Autowired  
public B(@Qualifier("beanname")A a){...} //  you need to add @autowire also 

//property
@Autowired
@Qualifier("beanname")
private A a;

}

//If you don't want to add the two annotations, we can use @Resource
public class B{

//property
@Resource(name="beanname")
private A a;

//Importing properties is very similar
@Value("${property.name}")  //@Value know how to interpret ${}
private String name;
}

more about @value

Run PostgreSQL queries from the command line

Open a command prompt and go to the directory where Postgres installed. In my case my Postgres path is "D:\TOOLS\Postgresql-9.4.1-3".After that move to the bin directory of Postgres.So command prompt shows as "D:\TOOLS\Postgresql-9.4.1-3\bin>"
Now my goal is to select "UserName" from the users table using "UserId" value.So the database query is "Select u."UserName" from users u Where u."UserId"=1".

The same query is written as below for psql command prompt of postgres.

D:\TOOLS\Postgresql-9.4.1-3\bin>psql -U postgres -d DatabaseName -h localhost - t -c "Select u.\"UserName\" from users u Where u.\"UserId\"=1;

How to add a ScrollBar to a Stackpanel

It works like this:

<ScrollViewer VerticalScrollBarVisibility="Visible" HorizontalScrollBarVisibility="Disabled" Width="340" HorizontalAlignment="Left" Margin="12,0,0,0">
        <StackPanel Name="stackPanel1" Width="311">

        </StackPanel>
</ScrollViewer>

TextBox tb = new TextBox();
tb.TextChanged += new TextChangedEventHandler(TextBox_TextChanged);
stackPanel1.Children.Add(tb);

-XX:MaxPermSize with or without -XX:PermSize

If you're doing some performance tuning it's often recommended to set both -XX:PermSize and -XX:MaxPermSize to the same value to increase JVM efficiency.

Here is some information:

You can also specify -XX:+CMSClassUnloadingEnabled to enable class unloading option if you are using CMS GC. It may help to decrease the probability of Java.lang.OutOfMemoryError: PermGen space

Disable pasting text into HTML form

Check validity of the MX record of the host of the given email. This can eliminate errors to the right of the @ sign.

You could do this with an AJAX call before submit and/or server side after the form is submitted.

How to find the difference in days between two dates?

This assumes that a month is 1/12 of a year:

#!/usr/bin/awk -f
function mktm(datespec) {
  split(datespec, q, "-")
  return q[1] * 365.25 + q[3] * 365.25 / 12 + q[2]
}
BEGIN {
  printf "%d\n", mktm(ARGV[2]) - mktm(ARGV[1])
}

How to insert a row in an HTML table body in JavaScript

Add Column, Add Row, Delete Column, Delete Row. Simplest way

_x000D_

    function addColumn(myTable) {
      var table = document.getElementById(myTable);
      var row = table.getElementsByTagName('tr');
      for(i=0;i<row.length;i++){
        row[i].innerHTML = row[i].innerHTML + '<td></td>';
      }
    }
    function deleterow(tblId)
    {
        
      var table = document.getElementById(tblId);
      var row = table.getElementsByTagName('tr');
            if(row.length!='1'){
                row[row.length - 1].outerHTML='';
            }
    }
    function deleteColumn(tblId)
    {
        var allRows = document.getElementById(tblId).rows;
        for (var i=0; i<allRows.length; i++) {
            if (allRows[i].cells.length > 1) {
                allRows[i].deleteCell(-1);
            }
        }
    }
    function myFunction(myTable) {
      var table = document.getElementById(myTable);
      var row = table.getElementsByTagName('tr');
      var row = row[row.length-1].outerHTML;
      table.innerHTML = table.innerHTML + row;
      var row = table.getElementsByTagName('tr');
      var row = row[row.length-1].getElementsByTagName('td');
      for(i=0;i<row.length;i++){
        row[i].innerHTML = '';
      }
    }

_x000D_

    table, td {
      border: 1px solid black;
      border-collapse:collapse;
    }
    td {
      cursor:text;
      padding:10px;
    }
    td:empty:after{
      content:"Type here...";
      color:#cccccc;
    }

_x000D_

   <!DOCTYPE html>
    <html>
    <head>
    </head>
    <body>
    <form>
    <p>
    <input type="button" value="+Column" onclick="addColumn('tblSample')">
    <input type="button" value="-Column" onclick="deleteColumn('tblSample')">
    <input type="button" value="+Row" onclick="myFunction('tblSample')">
    <input type="button" value="-Row" onclick="deleterow('tblSample')">
    </p>
    <table id="tblSample" contenteditable><tr><td></td></tr></table>
    </form>

    </body>
    </html>

_x000D_

Android Log.v(), Log.d(), Log.i(), Log.w(), Log.e() - When to use each one?

The source code provides some basic guidance:

The order in terms of verbosity, from least to most is ERROR, WARN, INFO, DEBUG, VERBOSE. Verbose should never be compiled into an application except during development. Debug logs are compiled in but stripped at runtime. Error, warning and info logs are always kept.

For more detail, Kurtis' answer is dead on. I would just add: Don't log any personally identifiable or private information at INFO or above (WARN/ERROR). Otherwise, bug reports or anything else that includes logging may be polluted.

Node Express sending image files as API response

There is an api in Express.

res.sendFile

app.get('/report/:chart_id/:user_id', function (req, res) {
    // res.sendFile(filepath);
});

http://expressjs.com/en/api.html#res.sendFile

How do I see if Wi-Fi is connected on Android?

The following code (in Kotlin) works from API 21 until at least current API version (API 29). The function getWifiState() returns one of 3 possible values for the WiFi network state: Disable, EnabledNotConnected and Connected that were defined in an enum class. This allows to take more granular decisions like informing the user to enable WiFi or, if already enabled, to connect to one of the available networks. But if all that is needed is a boolean indicating if the WiFi interface is connected to a network, then the other function isWifiConnected() will give you that. It uses the previous one and compares the result to Connected.

It's inspired in some of the previous answers but trying to solve the problems introduced by the evolution of Android API's or the slowly increasing availability of IP V6. The trick was to use:

wifiManager.connectionInfo.bssid != null

instead of:

getIpAddress() == 0 that is only valid for IP V4 or
getNetworkId() == -1 that now requires another special permission (Location)

According to the documentation: https://developer.android.com/reference/kotlin/android/net/wifi/WifiInfo.html#getbssid it will return null if not connected to a network. And even if we do not have permission to get the real value, it will still return something other than null if we are connected.

Also have the following in mind:

On releases before android.os.Build.VERSION_CODES#N, this object should only be obtained from an Context#getApplicationContext(), and not from any other derived context to avoid memory leaks within the calling process.

In the Manifest, do not forget to add:

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

Proposed code is:

class MyViewModel(application: Application) : AndroidViewModel(application) {

   // Get application context
    private val myAppContext: Context = getApplication<Application>().applicationContext

   // Define the different possible states for the WiFi Connection
    internal enum class WifiState {
        Disabled,               // WiFi is not enabled
        EnabledNotConnected,    // WiFi is enabled but we are not connected to any WiFi network
        Connected,              // Connected to a WiFi network
    }

    // Get the current state of the WiFi network
    private fun getWifiState() : WifiState {

        val wifiManager : WifiManager = myAppContext.applicationContext.getSystemService(Context.WIFI_SERVICE) as WifiManager

        return if (wifiManager.isWifiEnabled) {
                    if (wifiManager.connectionInfo.bssid != null)
                        WifiState.Connected
                    else
                        WifiState.EnabledNotConnected
               } else {
                    WifiState.Disabled
               }
    }

    // Returns true if we are connected to a WiFi network
    private fun isWiFiConnected() : Boolean {
        return (getWifiState() == WifiState.Connected)
    }
}

what does this mean ? image/png;base64?

That is, you are referencing an image, but instead of providing an external url, the png image data is in the url itself, embedded in the style sheet. data:image/png;base64 tells the browser that the data is inline, is a png image and is in this case base64 encoded. The encoding is needed because png images can contain bytes that are invalid inside a HTML document (or within the HTTP protocol even).

JavaScript Number Split into individual digits

You can work on strings instead of numbers to achieve this. You can do it like this

(111 + '').split('')

This will return an array of strings ['1','1','1'] on which you can iterate upon and call parseInt method.

parseInt('1') === 1

If you want the sum of individual digits, you can use the reduce function (implemented from Javascript 1.8) like this

(111 + '').split('').reduce(function(previousValue, currentValue){  
  return parseInt(previousValue,10) + parseInt(currentValue,10);  
})

Update label from another thread

Use MethodInvoker for updating label text in other thread.

private void AggiornaContatore()
{
    MethodInvoker inv = delegate 
    {
      this.lblCounter.Text = this.index.ToString(); 
    }

 this.Invoke(inv);
}

You are getting the error because your UI thread is holding the label, and since you are trying to update it through another thread you are getting cross thread exception.

You may also see: Threading in Windows Forms

Android map v2 zoom to show all the markers

Working fine for me.

From this code, I am displaying multiple markers with particular zoom on map screen.

// Declared variables

private LatLngBounds bounds;
private LatLngBounds.Builder builder;

// Method for adding multiple marker points with drawable icon

private void drawMarker(LatLng point, String text) {

        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(point).title(text).icon(BitmapDescriptorFactory.fromResource(R.drawable.icon));
        mMap.addMarker(markerOptions);
        builder.include(markerOptions.getPosition());

    }

// For adding multiple markers visible on map

@Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        builder = new LatLngBounds.Builder();
    for (int i = 0; i < locationList.size(); i++) {

        drawMarker(new LatLng(Double.parseDouble(locationList.get(i).getLatitude()), Double.parseDouble(locationList.get(i).getLongitude())), locationList.get(i).getNo());

     }
     bounds = builder.build();
     CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, 0);
     mMap.animateCamera(cu);

JQuery Ajax Post results in 500 Internal Server Error

You can also get that error in VB if the function you're calling starts with Public Shared Function rather than Public Function in the webservice. (As might happen if you move or copy the function out of a class). Just another thing to watch for.

How to use ArrayList's get() method

Would this help?

final List<String> l = new ArrayList<String>();
for (int i = 0; i < 10; i++) l.add("Number " + i);
for (int i = 0; i < 10; i++) System.out.println(l.get(i));

Apache won't follow symlinks (403 Forbidden)

I was having a similar problem that I could not resolve for a long time on my new server. In addition to palacsint's answer, a good question to ask is: are you using Apache 2.4? In Apache 2.4 there is a different mechanism for setting the permissions that do not work when done using the above configuration, so I used the solution explained in this blog post.

Basically, what I needed to do was convert my config file from:

Alias /demo /usr/demo/html

<Directory "/usr/demo/html">
    Options FollowSymLinks
    AllowOverride None
    Order allow,deny
    allow from all

</Directory>

to:

Alias /demo /usr/demo/html

<Directory "/usr/demo/html">
    Options FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>

Note how the Order and allow lines have been replaced by Require all granted

In CSS Flexbox, why are there no "justify-items" and "justify-self" properties?

This was asked on the www-style list, and Tab Atkins (spec editor) provided an answer explaining why. I'll elaborate on that a bit here.

To start out, let's initially assume our flex container is single-line (flex-wrap: nowrap). In this case, there's clearly an alignment difference between the main axis and the cross axis -- there are multiple items stacked in the main axis, but only one item stacked in the cross axis. So it makes sense to have a customizeable-per-item "align-self" in the cross axis (since each item is aligned separately, on its own), whereas it doesn't make sense in the main axis (since there, the items are aligned collectively).

For multi-line flexbox, the same logic applies to each "flex line". In a given line, items are aligned individually in the cross axis (since there's only one item per line, in the cross axis), vs. collectively in the main axis.

Here's another way of phrasing it: so, all of the *-self and *-content properties are about how to distribute extra space around things. But the key difference is that the *-self versions are for cases where there's only a single thing in that axis, and the *-content versions are for when there are potentially many things in that axis. The one-thing vs. many-things scenarios are different types of problems, and so they have different types of options available -- for example, the space-around / space-between values make sense for *-content, but not for *-self.

SO: In a flexbox's main axis, there are many things to distribute space around. So a *-content property makes sense there, but not a *-self property.

In contrast, in the cross axis, we have both a *-self and a *-content property. One determines how we'll distribute space around the many flex lines (align-content), whereas the other (align-self) determines how to distribute space around individual flex items in the cross axis, within a given flex line.

(I'm ignoring *-items properties here, since they simply establish defaults for *-self.)

How do I fix twitter-bootstrap on IE?

If you are using responsive layout, try including this js on your code: https://github.com/scottjehl/Respond

Declare a Range relative to the Active Cell with VBA

Like this:

Dim rng as Range
Set rng = ActiveCell.Resize(numRows, numCols)

then read the contents of that range to an array:

Dim arr As Variant
arr = rng.Value
'arr is now a two-dimensional array of size (numRows, numCols)

or, select the range (I don't think that's what you really want, but you ask for this in the question).

rng.Select

Equivalent of SQL ISNULL in LINQ?

You can use the ?? operator to set the default value but first you must set the Nullable property to true in your dbml file in the required field (xx.Online)

var hht = from x in db.HandheldAssets
        join a in db.HandheldDevInfos on x.AssetID equals a.DevName into DevInfo
        from aa in DevInfo.DefaultIfEmpty()
        select new
        {
        AssetID = x.AssetID,
        Status = xx.Online ?? false
        };

Should operator<< be implemented as a friend or as a member function?

friend operator = equal rights as class

friend std::ostream& operator<<(std::ostream& os, const Object& object) {
    os << object._atribute1 << " " << object._atribute2 << " " << atribute._atribute3 << std::endl;
    return os;
}

I get Access Forbidden (Error 403) when setting up new alias

try this

sudo chmod -R 0777 /opt/lampp/htdocs/testproject

How to darken a background using CSS?

You can use a container for your background, placed as absolute and negative z-index : http://jsfiddle.net/2YW7g/

HTML

<div class="main">
    <div class="bg">         
    </div>
    Hello World!!!!
</div>

CSS

.main{
    width:400px;
    height:400px;
    position:relative;
    color:red;
    background-color:transparent;
    font-size:18px;
}
.main .bg{
    position:absolute;
      width:400px;
    height:400px;
    background-image:url("http://fc02.deviantart.net/fs71/i/2011/274/6/f/ocean__sky__stars__and_you_by_muddymelly-d4bg1ub.png");
    z-index:-1;
}

.main:hover .bg{
    opacity:0.5;
}

MVC ajax post to controller action method

It's due to you sending one object, and you're expecting two parameters.

Try this and you'll see:

public class UserDetails
{
   public string username { get; set; }
   public string password { get; set; }
}

public JsonResult Login(UserDetails data)
{
   string error = "";
   //the rest of your code
}

How to copy commits from one branch to another?

You should really have a workflow that lets you do this all by merging:

- x - x - x (v2) - x - x - x (v2.1)
           \
            x - x - x (wss)

So all you have to do is git checkout v2.1 and git merge wss. If for some reason you really can't do this, and you can't use git rebase to move your wss branch to the right place, the command to grab a single commit from somewhere and apply it elsewhere is git cherry-pick. Just check out the branch you want to apply it on, and run git cherry-pick <SHA of commit to cherry-pick>.

Some of the ways rebase might save you:

If your history looks like this:

- x - x - x (v2) - x - x - x (v2.1)
           \
            x - x - x (v2-only) - x - x - x (wss)

You could use git rebase --onto v2 v2-only wss to move wss directly onto v2:

- x - x - x (v2) - x - x - x (v2.1)
          |\
          |  x - x - x (v2-only)
           \
             x - x - x (wss)

Then you can merge! If you really, really, really can't get to the point where you can merge, you can still use rebase to effectively do several cherry-picks at once:

# wss-starting-point is the SHA1/branch immediately before the first commit to rebase
git branch wss-to-rebase wss
git rebase --onto v2.1 wss-starting-point wss-to-rebase
git checkout v2.1
git merge wss-to-rebase

Note: the reason that it takes some extra work in order to do this is that it's creating duplicate commits in your repository. This isn't really a good thing - the whole point of easy branching and merging is to be able to do everything by making commit(s) one place and merging them into wherever they're needed. Duplicate commits mean an intent never to merge those two branches (if you decide you want to later, you'll get conflicts).

Django - makemigrations - No changes detected

First of all, make sure your app is registered in the Installed_app in the setting.py Then the above answer works perfectly fine

How do I time a method's execution in Java?

new Timer(""){{
    // code to time 
}}.timeMe();



public class Timer {

    private final String timerName;
    private long started;

    public Timer(String timerName) {
        this.timerName = timerName;
        this.started = System.currentTimeMillis();
    }

    public void timeMe() {
        System.out.println(
        String.format("Execution of '%s' takes %dms.", 
                timerName, 
                started-System.currentTimeMillis()));
    }

}

jquery get all form elements: input, textarea & select

The below code helps to get the details of elements from the specific form with the form id,

$('#formId input, #formId select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements from all the forms which are place in the loading page,

$('form input, form select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements which are place in the loading page even when the element is not place inside the tag,

$('input, select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

NOTE: We add the more element tag name what we need in the object list like as below,

Example: to get name of attribute "textarea",

$('input, select, textarea').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

How to check whether Kafka Server is running?

I found an event OnError in confluent Kafka:

consumer.OnError += Consumer_OnError;

 private void Consumer_OnError(object sender, Error e)
    {
        Debug.Log("connection error: "+ e.Reason);
        ConsumerConnectionError(e);
    }

And its documentation in code:

    //
    // Summary:
    //     Raised on critical errors, e.g. connection failures or all brokers down. Note
    //     that the client will try to automatically recover from errors - these errors
    //     should be seen as informational rather than catastrophic
    //
    // Remarks:
    //     Executes on the same thread as every other Consumer event handler (except OnLog
    //     which may be called from an arbitrary thread).
    public event EventHandler<Error> OnError;

Reading json files in C++

Essentially javascript and C++ work on two different principles. Javascript creates an "associative array" or hash table, which matches a string key, which is the field name, to a value. C++ lays out structures in memory, so the first 4 bytes are an integer, which is an age, then maybe we have a fixed-wth 32 byte string which represents the "profession".

So javascript will handle things like "age" being 18 in one record and "nineteen" in another. C++ can't. (However C++ is much faster).

So if we want to handle JSON in C++, we have to build the associative array from the ground up. Then we have to tag the values with their types. Is it an integer, a real value (probably return as "double"), boolean, a string? It follows that a JSON C++ class is quite a large chunk of code. Effectively what we are doing is implementing a bit of the javascript engine in C++. We then pass our JSON parser the JSON as a string, and it tokenises it, and gives us functions to query the JSON from C++.

Two arrays in foreach loop

foreach only works with a single array. To step through multiple arrays, it's better to use the each() function in a while loop:

while(($code = each($codes)) && ($name = each($names))) {
    echo '<option value="' . $code['value'] . '">' . $name['value'] . '</option>';
}

each() returns information about the current key and value of the array and increments the internal pointer by one, or returns false if it has reached the end of the array. This code would not be dependent upon the two arrays having identical keys or having the same sort of elements. The loop terminates when one of the two arrays is finished.

How do I see which checkbox is checked?

I love short hands so:

$isChecked = isset($_POST['myCheckbox']) ? "yes" : "no";

How to Create a circular progressbar in Android which rotates on it?

Here are my two solutions.

Short answer:

Instead of creating a layer-list, I separated it into two files. One for ProgressBar and one for its background.

This is the ProgressDrawable file (@drawable folder): circular_progress_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="270"
    android:toDegrees="270">
    <shape
        android:innerRadiusRatio="2.5"
        android:shape="ring"
        android:thickness="1dp"
        android:useLevel="true"><!-- this line fixes the issue for lollipop api 21 -->

        <gradient
            android:angle="0"
            android:endColor="#007DD6"
            android:startColor="#007DD6"
            android:type="sweep"
            android:useLevel="false" />
    </shape>
</rotate>

And this is for its background(@drawable folder): circle_shape.xml

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="ring"
    android:innerRadiusRatio="2.5"
    android:thickness="1dp"
    android:useLevel="false">

    <solid android:color="#CCC" />

</shape>

And at the end, inside the layout that you're working:

<ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:indeterminate="false"
        android:progressDrawable="@drawable/circular_progress_bar"
        android:background="@drawable/circle_shape"
        style="?android:attr/progressBarStyleHorizontal"
        android:max="100"
        android:progress="65" />

Here's the result:

result 1

Long Answer:

Use a custom view which inherits the android.view.View

result 2

Here is the full project on github

Datatables warning(table id = 'example'): cannot reinitialise data table

$('#example').dataTable();

Make it a class so you can instantiate multiple table at a time

$('.example').dataTable();

Equal height rows in CSS Grid Layout

Short Answer

If the goal is to create a grid with equal height rows, where the tallest cell in the grid sets the height for all rows, here's a quick and simple solution:

Set the container to grid-auto-rows: 1fr

How it works

Grid Layout provides a unit for establishing flexible lengths in a grid container. This is the fr unit. It is designed to distribute free space in the container and is somewhat analogous to the flex-grow property in flexbox.

If you set all rows in a grid container to 1fr, let's say like this:

grid-auto-rows: 1fr;

... then all rows will be equal height.

It doesn't really make sense off-the-bat because fr is supposed to distribute free space. And if several rows have content with different heights, then when the space is distributed, some rows would be proportionally smaller and taller.

Except, buried deep in the grid spec is this little nugget:

7.2.3. Flexible Lengths: the fr unit

...

When the available space is infinite (which happens when the grid container’s width or height is indefinite), flex-sized (fr) grid tracks are sized to their contents while retaining their respective proportions.

The used size of each flex-sized grid track is computed by determining the max-content size of each flex-sized grid track and dividing that size by the respective flex factor to determine a “hypothetical 1fr size”.

The maximum of those is used as the resolved 1fr length (the flex fraction), which is then multiplied by each grid track’s flex factor to determine its final size.

So, if I'm reading this correctly, when dealing with a dynamically-sized grid (e.g., the height is indefinite), grid tracks (rows, in this case) are sized to their contents.

The height of each row is determined by the tallest (max-content) grid item.

The maximum height of those rows becomes the length of 1fr.

That's how 1fr creates equal height rows in a grid container.

Why flexbox isn't an option

As noted in the question, equal height rows are not possible with flexbox.

Flex items can be equal height on the same row, but not across multiple rows.

This behavior is defined in the flexbox spec:

6. Flex Lines

In a multi-line flex container, the cross size of each line is the minimum size necessary to contain the flex items on the line.

In other words, when there are multiple lines in a row-based flex container, the height of each line (the "cross size") is the minimum height necessary to contain the flex items on the line.

Turn off constraints temporarily (MS SQL)

You can disable FK and CHECK constraints ~~only in SQL 2005+~~. See ALTER TABLE

ALTER TABLE foo NOCHECK CONSTRAINT ALL

ALTER TABLE foo NOCHECK CONSTRAINT CK_foo_column

Primary keys and unique constraints can not be disabled, but this should be OK if I've understood you correctly.

enable or disable checkbox in html

The HTML parser simply doesn't interpret the inlined javascript like this.

You may do this :

<td><input type="checkbox" id="repriseCheckBox" name="repriseCheckBox"/></td>

<script>document.getElementById("repriseCheckBox").disabled=checkStat == 1 ? true : false;</script>

How to modify the nodejs request default timeout time?

Linking to express issue #3330

You may set the timeout either globally for entire server:

var server = app.listen();
server.setTimeout(500000);

or just for specific route:

app.post('/xxx', function (req, res) {
   req.setTimeout(500000);
});

Regular expression for only characters a-z, A-Z

This /[^a-z]/g solves the problem.

_x000D_

function pangram(str) {
    let regExp = /[^a-z]/g;
    let letters = str.toLowerCase().replace(regExp, '');
    document.getElementById('letters').innerHTML = letters;
}
pangram('GHV 2@# %hfr efg uor7 489(*&^% knt lhtkjj ngnm!@#$%^&*()_');

_x000D_

<h4 id="letters"></h4>

_x000D_

How to make a section of an image a clickable link

The easiest way is to make the "button image" as a separate image. Then place it over the main image (using "style="position: absolute;". Assign the URL link to "button image". and smile :)

How do I tell if an object is a Promise?

I use this function as a universal solution:

function isPromise(value) {
  return value && value.then && typeof value.then === 'function';
}

Create an empty list in python with certain size

There are two "quick" methods:

x = length_of_your_list
a = [None]*x
# or
a = [None for _ in xrange(x)]

It appears that [None]*x is faster:

>>> from timeit import timeit
>>> timeit("[None]*100",number=10000)
0.023542165756225586
>>> timeit("[None for _ in xrange(100)]",number=10000)
0.07616496086120605

But if you are ok with a range (e.g. [0,1,2,3,...,x-1]), then range(x) might be fastest:

>>> timeit("range(100)",number=10000)
0.012513160705566406

'pip install' fails for every package ("Could not find a version that satisfies the requirement")

Support for TLS 1.0 and 1.1 was dropped for PyPI. If your system does not use a more recent version, it could explain your error.

Could you try reinstalling pip system-wide, to update your system dependencies to a newer version of TLS?

This seems to be related to Unable to install Python libraries

See Dominique Barton's answer:

Apparently pip is trying to access PyPI via HTTPS (which is encrypted and fine), but with an old (insecure) SSL version. Your system seems to be out of date. It might help if you update your packages.

On Debian-based systems I'd try:
apt-get update && apt-get upgrade python-pip
On Red Hat Linux-based systems:
yum update python-pip # (or python2-pip, at least on Red Hat Linux 7)
On Mac:
sudo easy_install -U pip
You can also try to update openssl separately.

Git: list only "untracked" files (also, custom commands)

git add -A -n will do what you want. -A adds all untracked files to the repo, -n makes it a dry-run where the add isn't performed but the status output is given listing each file that would have been added.

How to set max and min value for Y axis

I wrote a js to display values from 0 to 100 in y-axis with a gap of 20.

This is my script.js

_x000D_

//x-axis_x000D_
var vehicles = ["Trucks", "Cars", "Bikes", "Jeeps"];_x000D_
_x000D_
//The percentage of vehicles of each type_x000D_
var percentage = [41, 76, 29, 50];_x000D_
_x000D_
var ctx = document.getElementById("barChart");_x000D_
var lineChart = new Chart(ctx, {_x000D_
  type: 'bar',_x000D_
  data: {_x000D_
    labels: vehicles,_x000D_
    datasets: [{_x000D_
      data: percentage,_x000D_
      label: "Percentage of vehicles",_x000D_
      backgroundColor: "#3e95cd",_x000D_
      fill: false_x000D_
    }]_x000D_
  },_x000D_
  options: {_x000D_
    scales: {_x000D_
      yAxes: [{_x000D_
        ticks: {_x000D_
          beginAtZero: true,_x000D_
          min: 0,_x000D_
          max: 100,_x000D_
          stepSize: 20,_x000D_
        }_x000D_
      }]_x000D_
    }_x000D_
  }_x000D_
});

_x000D_

This is the graph displayed on the web.

How to disable a ts rule for a specific line?

`@ts-expect-error`

TS 3.9 introduces a new magic comment. @ts-expect-error will:

have same functionality as @ts-ignore
trigger an error, if actually no compiler error has been suppressed (= indicates useless flag)

if (false) {
  // @ts-expect-error: Let's ignore a single compiler error like this unreachable code 
  console.log("hello"); // compiles
}

// If @ts-expect-error didn't suppress anything at all, we now get a nice warning 
let flag = true;
// ...
if (flag) {
  // @ts-expect-error
  // ^~~~~~~~~~~~~~~^ error: "Unused '@ts-expect-error' directive.(2578)"
  console.log("hello"); 
}

Alternatives

@ts-ignore and @ts-expect-error can be used for all sorts of compiler errors. For type issues (like in OP), I recommend one of the following alternatives due to narrower error suppression scope:

? Use any type

// type assertion for single expression
delete ($ as any).summernote.options.keyMap.pc.TAB;

// new variable assignment for multiple usages
const $$: any = $
delete $$.summernote.options.keyMap.pc.TAB;
delete $$.summernote.options.keyMap.mac.TAB;

? Augment JQueryStatic interface

// ./global.d.ts
interface JQueryStatic {
  summernote: any;
}

// ./main.ts
delete $.summernote.options.keyMap.pc.TAB; // works

In other cases, shorthand module declarations or module augmentations for modules with no/extendable types are handy utilities. A viable strategy is also to keep not migrated code in .js and use --allowJs with checkJs: false.

Not equal string

Try this:

if(myString != "-1")

The opperand is != and not =!

You can also use Equals

if(!myString.Equals("-1"))

Note the ! before myString

Bash scripting, multiple conditions in while loop

Try:

while [ $stats -gt 300 -o $stats -eq 0 ]

[ is a call to test. It is not just for grouping, like parentheses in other languages. Check man [ or man test for more information.

What are all possible pos tags of NLTK?

You can download the list here: ftp://ftp.cis.upenn.edu/pub/treebank/doc/tagguide.ps.gz. It includes confusing parts of speech, capitalization, and other conventions. Also, wikipedia has an interesting section similar to this. Section: Part-of-speech tags used.

Why does Boolean.ToString output "True" and not "true"

For Xml you can use XmlConvert.ToString method.

Uncaught TypeError: Cannot use 'in' operator to search for 'length' in

The only solution that worked for me and $.each was definitely causing the error. so i used for loop and it's not throwing error anymore.

Example code

     $.ajax({
            type: 'GET',
            url: 'https://example.com/api',
            data: { get_param: 'value' },
            success: function (data) {
                for (var i = 0; i < data.length; ++i) {
                    console.log(data[i].NameGerman);
                }
            }
        });

How to connect to SQL Server database from JavaScript in the browser?

I dont think you can connect to SQL server from client side javascripts. You need to pick up some server side language to build web applications which can interact with your database and use javascript only to make your user interface better to interact with.

you can pick up any server side scripting language based on your language preference :

PHP
ASP.Net
Ruby On Rails

Display images in asp.net mvc

It is possible to use a handler to do this, even in MVC4. Here's an example from one i made earlier:

public class ImageHandler : IHttpHandler
{
    byte[] bytes;

    public void ProcessRequest(HttpContext context)
    {
        int param;
        if (int.TryParse(context.Request.QueryString["id"], out param))
        {
            using (var db = new MusicLibContext())
            {
                if (param == -1)
                {
                    bytes = File.ReadAllBytes(HttpContext.Current.Server.MapPath("~/Images/add.png"));

                    context.Response.ContentType = "image/png";
                }
                else
                {
                    var data = (from x in db.Images
                                where x.ImageID == (short)param
                                select x).FirstOrDefault();

                    bytes = data.ImageData;

                    context.Response.ContentType = "image/" + data.ImageFileType;
                }

                context.Response.Cache.SetCacheability(HttpCacheability.NoCache);
                context.Response.BinaryWrite(bytes);
                context.Response.Flush();
                context.Response.End();
            }
        }
        else
        {
            //image not found
        }
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}

In the view, i added the ID of the photo to the query string of the handler.

Javascript Print iframe contents only

document.getElementById("printf").contentWindow.print();

Same origin policy applies.

How do I see which version of Swift I'm using?

You can see and select which Swift version Xcode is using in:

Target -> Build Settings -> Swift Language Version:

This is available in Xcode 8.3 and Xcode 9 (haven't checked older versions)

Creating the checkbox dynamically using JavaScript?

The last line should read

cbh.appendChild(document.createTextNode(cap));

Appending the text (label?) to the same container as the checkbox, not the checkbox itself

CSS3 Transition not working

Transition is more like an animation.

div.sicon a {
    background:-moz-radial-gradient(left, #ffffff 24%, #cba334 88%);
    transition: background 0.5s linear;
    -moz-transition: background 0.5s linear; /* Firefox 4 */
    -webkit-transition: background 0.5s linear; /* Safari and Chrome */
    -o-transition: background 0.5s linear; /* Opera */
    -ms-transition: background 0.5s linear; /* Explorer 10 */
}

So you need to invoke that animation with an action.

div.sicon a:hover {
    background:-moz-radial-gradient(left, #cba334 24%, #ffffff 88%);
}

Also check for browser support and if you still have some problem with whatever you're trying to do! Check css-overrides in your stylesheet and also check out for behavior: ***.htc css hacks.. there may be something overriding your transition!

You should check this out: http://www.w3schools.com/css/css3_transitions.asp

Javascript to stop HTML5 video playback on modal window close

Have a try:

_x000D_

function stop(){_x000D_
    var video = document.getElementById("video");_x000D_
    video.load();_x000D_
}

_x000D_

HTML Upload MAX_FILE_SIZE does not appear to work

Before I start, please let me emphasize that the size of the file must be checked on the server side. If not checked on server side, malicious users can override your client side limits, and upload huge files to your server. DO NOT TRUST THE USERS.

I played a bit with PHP's MAX_FILE_SIZE, it seemed to work only after the file was uploaded, which makes it irrelevant (again, malicious user can override it quite easily).

The javascript code below (tested in Firefox and Chrome), based on Matthew's post, will warn the user (the good, innocent one) a priori to uploading a large file, saving both traffic and the user's time:

<form method="post" enctype="multipart/form-data" 
onsubmit="return checkSize(2097152)">    
<input type="file" id="upload" />
<input type="submit" />

<script type="text/javascript">
function checkSize(max_img_size)
{
    var input = document.getElementById("upload");
    // check for browser support (may need to be modified)
    if(input.files && input.files.length == 1)
    {           
        if (input.files[0].size > max_img_size) 
        {
            alert("The file must be less than " + (max_img_size/1024/1024) + "MB");
            return false;
        }
    }

    return true;
}
</script>

What are the nuances of scope prototypal / prototypical inheritance in AngularJS?

Quick answer:
A child scope normally prototypically inherits from its parent scope, but not always. One exception to this rule is a directive with scope: { ... } -- this creates an "isolate" scope that does not prototypically inherit. This construct is often used when creating a "reusable component" directive.

As for the nuances, scope inheritance is normally straightfoward... until you need 2-way data binding (i.e., form elements, ng-model) in the child scope. Ng-repeat, ng-switch, and ng-include can trip you up if you try to bind to a primitive (e.g., number, string, boolean) in the parent scope from inside the child scope. It doesn't work the way most people expect it should work. The child scope gets its own property that hides/shadows the parent property of the same name. Your workarounds are

define objects in the parent for your model, then reference a property of that object in the child: parentObj.someProp
use $parent.parentScopeProperty (not always possible, but easier than 1. where possible)
define a function on the parent scope, and call it from the child (not always possible)

New AngularJS developers often do not realize that ng-repeat, ng-switch, ng-view, ng-include and ng-if all create new child scopes, so the problem often shows up when these directives are involved. (See this example for a quick illustration of the problem.)

This issue with primitives can be easily avoided by following the "best practice" of always have a '.' in your ng-models – watch 3 minutes worth. Misko demonstrates the primitive binding issue with ng-switch.

Having a '.' in your models will ensure that prototypal inheritance is in play. So, use

<input type="text" ng-model="someObj.prop1">

<!--rather than
<input type="text" ng-model="prop1">`
-->

L-o-n-g answer:

JavaScript Prototypal Inheritance

Also placed on the AngularJS wiki: https://github.com/angular/angular.js/wiki/Understanding-Scopes

It is important to first have a solid understanding of prototypal inheritance, especially if you are coming from a server-side background and you are more familiar with class-ical inheritance. So let's review that first.

Suppose parentScope has properties aString, aNumber, anArray, anObject, and aFunction. If childScope prototypically inherits from parentScope, we have:

prototypal inheritance

(Note that to save space, I show the anArray object as a single blue object with its three values, rather than an single blue object with three separate gray literals.)

If we try to access a property defined on the parentScope from the child scope, JavaScript will first look in the child scope, not find the property, then look in the inherited scope, and find the property. (If it didn't find the property in the parentScope, it would continue up the prototype chain... all the way up to the root scope). So, these are all true:

childScope.aString === 'parent string'
childScope.anArray[1] === 20
childScope.anObject.property1 === 'parent prop1'
childScope.aFunction() === 'parent output'

Suppose we then do this:

childScope.aString = 'child string'

The prototype chain is not consulted, and a new aString property is added to the childScope. This new property hides/shadows the parentScope property with the same name. This will become very important when we discuss ng-repeat and ng-include below.

property hiding

Suppose we then do this:

childScope.anArray[1] = '22'
childScope.anObject.property1 = 'child prop1'

The prototype chain is consulted because the objects (anArray and anObject) are not found in the childScope. The objects are found in the parentScope, and the property values are updated on the original objects. No new properties are added to the childScope; no new objects are created. (Note that in JavaScript arrays and functions are also objects.)

follow the prototype chain

Suppose we then do this:

childScope.anArray = [100, 555]
childScope.anObject = { name: 'Mark', country: 'USA' }

The prototype chain is not consulted, and child scope gets two new object properties that hide/shadow the parentScope object properties with the same names.

more property hiding

Takeaways:

If we read childScope.propertyX, and childScope has propertyX, then the prototype chain is not consulted.
If we set childScope.propertyX, the prototype chain is not consulted.

One last scenario:

delete childScope.anArray
childScope.anArray[1] === 22  // true

We deleted the childScope property first, then when we try to access the property again, the prototype chain is consulted.

after removing a child property

Angular Scope Inheritance

The contenders:

The following create new scopes, and inherit prototypically: ng-repeat, ng-include, ng-switch, ng-controller, directive with scope: true, directive with transclude: true.
The following creates a new scope which does not inherit prototypically: directive with scope: { ... }. This creates an "isolate" scope instead.

Note, by default, directives do not create new scope -- i.e., the default is scope: false.

ng-include

Suppose we have in our controller:

$scope.myPrimitive = 50;
$scope.myObject    = {aNumber: 11};

And in our HTML:

<script type="text/ng-template" id="/tpl1.html">
<input ng-model="myPrimitive">
</script>
<div ng-include src="'/tpl1.html'"></div>

<script type="text/ng-template" id="/tpl2.html">
<input ng-model="myObject.aNumber">
</script>
<div ng-include src="'/tpl2.html'"></div>

Each ng-include generates a new child scope, which prototypically inherits from the parent scope.

ng-include child scopes

Typing (say, "77") into the first input textbox causes the child scope to get a new myPrimitive scope property that hides/shadows the parent scope property of the same name. This is probably not what you want/expect.

ng-include with a primitive

Typing (say, "99") into the second input textbox does not result in a new child property. Because tpl2.html binds the model to an object property, prototypal inheritance kicks in when the ngModel looks for object myObject -- it finds it in the parent scope.

ng-include with an object

We can rewrite the first template to use $parent, if we don't want to change our model from a primitive to an object:

<input ng-model="$parent.myPrimitive">

Typing (say, "22") into this input textbox does not result in a new child property. The model is now bound to a property of the parent scope (because $parent is a child scope property that references the parent scope).

ng-include with $parent

For all scopes (prototypal or not), Angular always tracks a parent-child relationship (i.e., a hierarchy), via scope properties $parent, $$childHead and $$childTail. I normally don't show these scope properties in the diagrams.

For scenarios where form elements are not involved, another solution is to define a function on the parent scope to modify the primitive. Then ensure the child always calls this function, which will be available to the child scope due to prototypal inheritance. E.g.,

// in the parent scope
$scope.setMyPrimitive = function(value) {
     $scope.myPrimitive = value;
}

Here is a sample fiddle that uses this "parent function" approach. (The fiddle was written as part of this answer: https://stackoverflow.com/a/14104318/215945.)

ng-switch

ng-switch scope inheritance works just like ng-include. So if you need 2-way data binding to a primitive in the parent scope, use $parent, or change the model to be an object and then bind to a property of that object. This will avoid child scope hiding/shadowing of parent scope properties.

ng-repeat

Ng-repeat works a little differently. Suppose we have in our controller:

$scope.myArrayOfPrimitives = [ 11, 22 ];
$scope.myArrayOfObjects    = [{num: 101}, {num: 202}]

And in our HTML:

<ul><li ng-repeat="num in myArrayOfPrimitives">
       <input ng-model="num">
    </li>
<ul>
<ul><li ng-repeat="obj in myArrayOfObjects">
       <input ng-model="obj.num">
    </li>
<ul>

For each item/iteration, ng-repeat creates a new scope, which prototypically inherits from the parent scope, but it also assigns the item's value to a new property on the new child scope. (The name of the new property is the loop variable's name.) Here's what the Angular source code for ng-repeat actually is:

childScope = scope.$new();  // child scope prototypically inherits from parent scope
...
childScope[valueIdent] = value;  // creates a new childScope property

If item is a primitive (as in myArrayOfPrimitives), essentially a copy of the value is assigned to the new child scope property. Changing the child scope property's value (i.e., using ng-model, hence child scope num) does not change the array the parent scope references. So in the first ng-repeat above, each child scope gets a num property that is independent of the myArrayOfPrimitives array:

ng-repeat with primitives

This ng-repeat will not work (like you want/expect it to). Typing into the textboxes changes the values in the gray boxes, which are only visible in the child scopes. What we want is for the inputs to affect the myArrayOfPrimitives array, not a child scope primitive property. To accomplish this, we need to change the model to be an array of objects.

So, if item is an object, a reference to the original object (not a copy) is assigned to the new child scope property. Changing the child scope property's value (i.e., using ng-model, hence obj.num) does change the object the parent scope references. So in the second ng-repeat above, we have:

ng-repeat with objects

(I colored one line gray just so that it is clear where it is going.)

This works as expected. Typing into the textboxes changes the values in the gray boxes, which are visible to both the child and parent scopes.

ng-controller

Nesting controllers using ng-controller results in normal prototypal inheritance, just like ng-include and ng-switch, so the same techniques apply. However, "it is considered bad form for two controllers to share information via $scope inheritance" -- http://onehungrymind.com/angularjs-sticky-notes-pt-1-architecture/ A service should be used to share data between controllers instead.

(If you really want to share data via controllers scope inheritance, there is nothing you need to do. The child scope will have access to all of the parent scope properties. See also Controller load order differs when loading or navigating)

directives

default (scope: false) - the directive does not create a new scope, so there is no inheritance here. This is easy, but also dangerous because, e.g., a directive might think it is creating a new property on the scope, when in fact it is clobbering an existing property. This is not a good choice for writing directives that are intended as reusable components.
scope: true - the directive creates a new child scope that prototypically inherits from the parent scope. If more than one directive (on the same DOM element) requests a new scope, only one new child scope is created. Since we have "normal" prototypal inheritance, this is like ng-include and ng-switch, so be wary of 2-way data binding to parent scope primitives, and child scope hiding/shadowing of parent scope properties.
scope: { ... } - the directive creates a new isolate/isolated scope. It does not prototypically inherit. This is usually your best choice when creating reusable components, since the directive cannot accidentally read or modify the parent scope. However, such directives often need access to a few parent scope properties. The object hash is used to set up two-way binding (using '=') or one-way binding (using '@') between the parent scope and the isolate scope. There is also '&' to bind to parent scope expressions. So, these all create local scope properties that are derived from the parent scope. Note that attributes are used to help set up the binding -- you can't just reference parent scope property names in the object hash, you have to use an attribute. E.g., this won't work if you want to bind to parent property parentProp in the isolated scope: <div my-directive> and scope: { localProp: '@parentProp' }. An attribute must be used to specify each parent property that the directive wants to bind to: <div my-directive the-Parent-Prop=parentProp> and scope: { localProp: '@theParentProp' }.
Isolate scope's __proto__ references Object. Isolate scope's $parent references the parent scope, so although it is isolated and doesn't inherit prototypically from the parent scope, it is still a child scope.
For the picture below we have
<my-directive interpolated="{{parentProp1}}" twowayBinding="parentProp2"> and
scope: { interpolatedProp: '@interpolated', twowayBindingProp: '=twowayBinding' }
Also, assume the directive does this in its linking function: scope.someIsolateProp = "I'm isolated"

For more information on isolate scopes see http://onehungrymind.com/angularjs-sticky-notes-pt-2-isolated-scope/
transclude: true - the directive creates a new "transcluded" child scope, which prototypically inherits from the parent scope. The transcluded and the isolated scope (if any) are siblings -- the $parent property of each scope references the same parent scope. When a transcluded and an isolate scope both exist, isolate scope property $$nextSibling will reference the transcluded scope. I'm not aware of any nuances with the transcluded scope.
For the picture below, assume the same directive as above with this addition: transclude: true

This fiddle has a showScope() function that can be used to examine an isolate and transcluded scope. See the instructions in the comments in the fiddle.

Summary

There are four types of scopes:

normal prototypal scope inheritance -- ng-include, ng-switch, ng-controller, directive with scope: true
normal prototypal scope inheritance with a copy/assignment -- ng-repeat. Each iteration of ng-repeat creates a new child scope, and that new child scope always gets a new property.
isolate scope -- directive with scope: {...}. This one is not prototypal, but '=', '@', and '&' provide a mechanism to access parent scope properties, via attributes.
transcluded scope -- directive with transclude: true. This one is also normal prototypal scope inheritance, but it is also a sibling of any isolate scope.

For all scopes (prototypal or not), Angular always tracks a parent-child relationship (i.e., a hierarchy), via properties $parent and $$childHead and $$childTail.

Diagrams were generated with graphviz "*.dot" files, which are on github. Tim Caswell's "Learning JavaScript with Object Graphs" was the inspiration for using GraphViz for the diagrams.

Regular Expression to match string starting with a specific word

If you want to match anything that starts with "stop" including "stop going", "stop" and "stopping" use:

^stop

If you want to match the word stop followed by anything as in "stop going", "stop this", but not "stopped" and not "stopping" use:

^stop\W

How to use Bootstrap 4 in ASP.NET Core

What does the trick for me is:

1) Right click on wwwroot > Add > Client Side Library

2) Typed "bootstrap" on the search box

3) Select "Choose specific files"

4) Scroll down and select a folder. In my case I chose "twitter-bootstrap"

5) Check "css" and "js"

6) Click "Install".

A few seconds later I have all of them wwwroot folder. Do the same for all client side packages that you want to add.

SQL Inner-join with 3 tables?

You can do the following (I guessed on table fields,etc)

SELECT s.studentname
    , s.studentid
    , s.studentdesc
    , h.hallname
FROM students s
INNER JOIN hallprefs hp
    on s.studentid = hp.studentid
INNER JOIN halls h
    on hp.hallid = h.hallid

Based on your request for multiple halls you could do it this way. You just join on your Hall table multiple times for each room pref id:

SELECT     s.StudentID
    , s.FName
    , s.LName
    , s.Gender
    , s.BirthDate
    , s.Email
    , r.HallPref1
    , h1.hallName as Pref1HallName
    , r.HallPref2 
    , h2.hallName as Pref2HallName
    , r.HallPref3
    , h3.hallName as Pref3HallName
FROM  dbo.StudentSignUp AS s 
INNER JOIN RoomSignUp.dbo.Incoming_Applications_Current AS r 
    ON s.StudentID = r.StudentID 
INNER JOIN HallData.dbo.Halls AS h1 
    ON r.HallPref1 = h1.HallID
INNER JOIN HallData.dbo.Halls AS h2
    ON r.HallPref2 = h2.HallID
INNER JOIN HallData.dbo.Halls AS h3
    ON r.HallPref3 = h3.HallID

Mipmaps vs. drawable folders

The mipmap folders are for placing your app/launcher icons (which are shown on the homescreen) in only. Any other drawable assets you use should be placed in the relevant drawable folders as before.

According to this Google blogpost:

It’s best practice to place your app icons in mipmap- folders (not the drawable- folders) because they are used at resolutions different from the device’s current density.

When referencing the mipmap- folders ensure you are using the following reference:

android:icon="@mipmap/ic_launcher"

The reason they use a different density is that some launchers actually display the icons larger than they were intended. Because of this, they use the next size up.

Get first element of Series without knowing the index

Use iloc to access by position (rather than label):

In [11]: df = pd.DataFrame([[1, 2], [3, 4]], ['a', 'b'], ['A', 'B'])

In [12]: df
Out[12]: 
   A  B
a  1  2
b  3  4

In [13]: df.iloc[0]  # first row in a DataFrame
Out[13]: 
A    1
B    2
Name: a, dtype: int64

In [14]: df['A'].iloc[0]  # first item in a Series (Column)
Out[14]: 1

Collectors.toMap() keyMapper -- more succinct expression?

You can use a lambda:

Collectors.toMap(p -> p.getLast(), Function.identity())

or, more concisely, you can use a method reference using :::

Collectors.toMap(Person::getLast, Function.identity())

and instead of Function.identity, you can simply use the equivalent lambda:

Collectors.toMap(Person::getLast, p -> p)

If you use Netbeans you should get hints whenever an anonymous class can be replaced by a lambda.

How to create EditText accepts Alphabets only in android?

Put code edittext xml file,

   android:digits="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

Why doesn't JavaScript support multithreading?

I don't know the rationale for this decision, but I know that you can simulate some of the benefits of multi-threaded programming using setTimeout. You can give the illusion of multiple processes doing things at the same time, though in reality, everything happens in one thread.

Just have your function do a little bit of work, and then call something like:

setTimeout(function () {
    ... do the rest of the work...
}, 0);

And any other things that need doing (like UI updates, animated images, etc) will happen when they get a chance.

Mixed mode assembly is built against version ‘v2.0.50727' of the runtime

Please add attribute useLegacyV2RuntimeActivationPolicy="true" in your applications app.config file.

Old Value

  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/>
  </startup>

New Value

  <startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/>
  </startup>

It will solve your problem.

Possible cases for Javascript error: "Expected identifier, string or number"

IE7 has problems with arrays of objects

columns: [
{
  field: "id",
  header: "ID"
},
{
  field: "name",
  header: "Name" , /* this comma was the problem*/ 
},
...

What is Android keystore file, and what is it used for?

The answer I would provide is that a keystore file is to authenticate yourself to anyone who is asking. It isn't restricted to just signing .apk files, you can use it to store personal certificates, sign data to be transmitted and a whole variety of authentication.

In terms of what you do with it for Android and probably what you're looking for since you mention signing apk's, it is your certificate. You are branding your application with your credentials. You can brand multiple applications with the same key, in fact, it is recommended that you use one certificate to brand multiple applications that you write. It easier to keep track of what applications belong to you.

I'm not sure what you mean by implications. I suppose it means that no one but the holder of your certificate can update your application. That means that if you release it into the wild, lose the cert you used to sign the application, then you cannot release updates so keep that cert safe and backed up if need be.

But apart from signing apks to release into the wild, you can use it to authenticate your device to a server over SSL if you so desire, (also Android related) among other functions.

Calling a class method raises a TypeError in Python

In python member function of a class need explicit self argument. Same as implicit this pointer in C++. For more details please check out this page.

Angular 2 TypeScript how to find element in Array

You need to use method Array.filter:

this.persons =  this.personService.getPersons().filter(x => x.id == this.personId)[0];

or Array.find

this.persons =  this.personService.getPersons().find(x => x.id == this.personId);

ASP.net Getting the error "Access to the path is denied." while trying to upload files to my Windows Server 2008 R2 Web server

the problem might be that networkservice has no read rights

salution:

rightclick your upload folder -> poperty's -> security ->Edit -> add -> type :NETWORK SERVICE -> check box full control allow-> press ok or apply

Java Generics With a Class & an Interface - Together

Actually, you can do what you want. If you want to provide multiple interfaces or a class plus interfaces, you have to have your wildcard look something like this:

<T extends ClassA & InterfaceB>

See the Generics Tutorial at sun.com, specifically the Bounded Type Parameters section, at the bottom of the page. You can actually list more than one interface if you wish, using & InterfaceName for each one that you need.

This can get arbitrarily complicated. To demonstrate, see the JavaDoc declaration of Collections#max, which (wrapped onto two lines) is:

public static <T extends Object & Comparable<? super T>> T
                                           max(Collection<? extends T> coll)

why so complicated? As said in the Java Generics FAQ: To preserve binary compatibility.

It looks like this doesn't work for variable declaration, but it does work when putting a generic boundary on a class. Thus, to do what you want, you may have to jump through a few hoops. But you can do it. You can do something like this, putting a generic boundary on your class and then:

class classB { }
interface interfaceC { }

public class MyClass<T extends classB & interfaceC> {
    Class<T> variable;
}

to get variable that has the restriction that you want. For more information and examples, check out page 3 of Generics in Java 5.0. Note, in <T extends B & C>, the class name must come first, and interfaces follow. And of course you can only list a single class.

Can a local variable's memory be accessed outside its scope?

After returning from a function, all identifiers are destroyed instead of kept values in a memory location and we can not locate the values without having an identifier.But that location still contains the value stored by previous function.

So, here function foo() is returning the address of a and a is destroyed after returning its address. And you can access the modified value through that returned address.

Let me take a real world example:

Suppose a man hides money at a location and tells you the location. After some time, the man who had told you the money location dies. But still you have the access of that hidden money.

How can I parse / create a date time stamp formatted with fractional seconds UTC timezone (ISO 8601, RFC 3339) in Swift?

Swift 4 • iOS 11.2.1 or later

extension ISO8601DateFormatter {
    convenience init(_ formatOptions: Options) {
        self.init()
        self.formatOptions = formatOptions
    }
}

extension Formatter {
    static let iso8601withFractionalSeconds = ISO8601DateFormatter([.withInternetDateTime, .withFractionalSeconds])
}

extension Date {
    var iso8601withFractionalSeconds: String { return Formatter.iso8601withFractionalSeconds.string(from: self) }
}

extension String {
    var iso8601withFractionalSeconds: Date? { return Formatter.iso8601withFractionalSeconds.date(from: self) }
}

Usage:

Date().description(with: .current)  //  Tuesday, February 5, 2019 at 10:35:01 PM Brasilia Summer Time"
let dateString = Date().iso8601withFractionalSeconds   //  "2019-02-06T00:35:01.746Z"

if let date = dateString.iso8601withFractionalSeconds {
    date.description(with: .current) // "Tuesday, February 5, 2019 at 10:35:01 PM Brasilia Summer Time"
    print(date.iso8601withFractionalSeconds)           //  "2019-02-06T00:35:01.746Z\n"
}

iOS 9 • Swift 3 or later

extension Formatter {
    static let iso8601withFractionalSeconds: DateFormatter = {
        let formatter = DateFormatter()
        formatter.calendar = Calendar(identifier: .iso8601)
        formatter.locale = Locale(identifier: "en_US_POSIX")
        formatter.timeZone = TimeZone(secondsFromGMT: 0)
        formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSXXXXX"
        return formatter
    }()
}

Codable Protocol

If you need to encode and decode this format when working with Codable protocol you can create your own custom date encoding/decoding strategies:

extension JSONDecoder.DateDecodingStrategy {
    static let iso8601withFractionalSeconds = custom {
        let container = try $0.singleValueContainer()
        let string = try container.decode(String.self)
        guard let date = Formatter.iso8601withFractionalSeconds.date(from: string) else {
            throw DecodingError.dataCorruptedError(in: container,
                  debugDescription: "Invalid date: " + string)
        }
        return date
    }
}

and the encoding strategy

extension JSONEncoder.DateEncodingStrategy {
    static let iso8601withFractionalSeconds = custom {
        var container = $1.singleValueContainer()
        try container.encode(Formatter.iso8601withFractionalSeconds.string(from: $0))
    }
}

Playground Testing

let dates = [Date()]   // ["Feb 8, 2019 at 9:48 PM"]

encoding

let encoder = JSONEncoder()
encoder.dateEncodingStrategy = .iso8601withFractionalSeconds
let data = try! encoder.encode(dates)
print(String(data: data, encoding: .utf8)!)

decoding

let decoder = JSONDecoder()
decoder.dateDecodingStrategy = .iso8601withFractionalSeconds
let decodedDates = try! decoder.decode([Date].self, from: data)  // ["Feb 8, 2019 at 9:48 PM"]

What are the uses of the exec command in shell scripts?

The exec built-in command mirrors functions in the kernel, there are a family of them based on execve, which is usually called from C.

exec replaces the current program in the current process, without forking a new process. It is not something you would use in every script you write, but it comes in handy on occasion. Here are some scenarios I have used it;

We want the user to run a specific application program without access to the shell. We could change the sign-in program in /etc/passwd, but maybe we want environment setting to be used from start-up files. So, in (say) .profile, the last statement says something like:
```
 exec appln-program
```
so now there is no shell to go back to. Even if appln-program crashes, the end-user cannot get to a shell, because it is not there - the exec replaced it.
We want to use a different shell to the one in /etc/passwd. Stupid as it may seem, some sites do not allow users to alter their sign-in shell. One site I know had everyone start with csh, and everyone just put into their .login (csh start-up file) a call to ksh. While that worked, it left a stray csh process running, and the logout was two stage which could get confusing. So we changed it to exec ksh which just replaced the c-shell program with the korn shell, and made everything simpler (there are other issues with this, such as the fact that the ksh is not a login-shell).
Just to save processes. If we call prog1 -> prog2 -> prog3 -> prog4 etc. and never go back, then make each call an exec. It saves resources (not much, admittedly, unless repeated) and makes shutdown simplier.

You have obviously seen exec used somewhere, perhaps if you showed the code that's bugging you we could justify its use.

Edit: I realised that my answer above is incomplete. There are two uses of exec in shells like ksh and bash - used for opening file descriptors. Here are some examples:

exec 3< thisfile          # open "thisfile" for reading on file descriptor 3
exec 4> thatfile          # open "thatfile" for writing on file descriptor 4
exec 8<> tother           # open "tother" for reading and writing on fd 8
exec 6>> other            # open "other" for appending on file descriptor 6
exec 5<&0                 # copy read file descriptor 0 onto file descriptor 5
exec 7>&4                 # copy write file descriptor 4 onto 7
exec 3<&-                 # close the read file descriptor 3
exec 6>&-                 # close the write file descriptor 6

Note that spacing is very important here. If you place a space between the fd number and the redirection symbol then exec reverts to the original meaning:

  exec 3 < thisfile       # oops, overwrite the current program with command "3"

There are several ways you can use these, on ksh use read -u or print -u, on bash, for example:

read <&3
echo stuff >&4

Best way to reverse a string

public static string Reverse2(string x)
        {
            char[] charArray = new char[x.Length];
            int len = x.Length - 1;
            for (int i = 0; i <= len; i++)
                charArray[i] = x[len - i];
            return new string(charArray);
        }

Simple way to encode a string according to a password?

Here's an implementation of URL Safe encryption and Decryption using AES(PyCrypto) and base64.

import base64
from Crypto import Random
from Crypto.Cipher import AES

AKEY = b'mysixteenbytekey' # AES key must be either 16, 24, or 32 bytes long

iv = Random.new().read(AES.block_size)

def encode(message):
    obj = AES.new(AKEY, AES.MODE_CFB, iv)
    return base64.urlsafe_b64encode(obj.encrypt(message))

def decode(cipher):
    obj2 = AES.new(AKEY, AES.MODE_CFB, iv)
    return obj2.decrypt(base64.urlsafe_b64decode(cipher))

If you face some issue like this https://bugs.python.org/issue4329 (TypeError: character mapping must return integer, None or unicode) use str(cipher) while decoding as follows:

return obj2.decrypt(base64.urlsafe_b64decode(str(cipher)))

Test:

In [13]: encode(b"Hello World")
Out[13]: b'67jjg-8_RyaJ-28='

In [14]: %timeit encode("Hello World")
100000 loops, best of 3: 13.9 µs per loop

In [15]: decode(b'67jjg-8_RyaJ-28=')
Out[15]: b'Hello World'

In [16]: %timeit decode(b'67jjg-8_RyaJ-28=')
100000 loops, best of 3: 15.2 µs per loop

Split value from one field to two

Method I used to split first_name into first_name and last_name when the data arrived all in the first_name field. This will put only the last word in the last name field, so "john phillips sousa" will be "john phillips" first name and "sousa" last name. It also avoids overwriting any records that have been fixed already.

set last_name=trim(SUBSTRING_INDEX(first_name, ' ', -1)), first_name=trim(SUBSTRING(first_name,1,length(first_name) - length(SUBSTRING_INDEX(first_name, ' ', -1)))) where list_id='$List_ID' and length(first_name)>0 and length(trim(last_name))=0

vertical & horizontal lines in matplotlib

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

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

With form validation: why onsubmit="return functionname()" instead of onsubmit="functionname()"?

When onsubmit (or any other event) is supplied as an HTML attribute, the string value of the attribute (e.g. "return validate();") is injected as the body of the actual onsubmit handler function when the DOM object is created for the element.

Here's a brief proof in the browser console:

var p = document.createElement('p');
p.innerHTML = '<form onsubmit="return validate(); // my statement"></form>';
var form = p.childNodes[0];

console.log(typeof form.onsubmit);
// => function

console.log(form.onsubmit.toString());
// => function onsubmit(event) {
//      return validate(); // my statement
//    }

So in case the return keyword is supplied in the injected statement; when the submit handler is triggered the return value received from validate function call will be passed over as the return value of the submit handler and thus take effect on controlling the submit behavior of the form.

Without the supplied return in the string, the generated onsubmit handler would not have an explicit return statement and when triggered it would return undefined (the default function return value) irrespective of whether validate() returns true or false and the form would be submitted in both cases.

How to call a View Controller programmatically?

There's 2 ways you can do this:

1, Create a segue to your ViewController in your Storyboard as explained in my answer here: How to perform a segue that is not related to user input in iOS 5?

2, Give your ViewController and identifier and call it using the code in my answer here: Call storyboard scene programmatically (without needing segue)?

Xcode 7 error: "Missing iOS Distribution signing identity for ..."

I also faced the same issue today. The following steps fixed my issue.

Download https://developer.apple.com/certificationauthority/AppleWWDRCA.cer
Double-click to install to Keychain.
Then in Keychain, Select View -> "Show Expired Certificates" in Keychain app.
It will list all the expired certifcates.
Delete "Apple Worldwide Developer Relations Certificate Authority certificates" from "login" tab
And also delete it from "System" tab.

Now you are ready go.

onclick open window and specific size

These are the best practices from Mozilla Developer Network's window.open page :

<script type="text/javascript">
var windowObjectReference = null; // global variable

function openFFPromotionPopup() {
  if(windowObjectReference == null || windowObjectReference.closed)
  /* if the pointer to the window object in memory does not exist
     or if such pointer exists but the window was closed */

  {
    windowObjectReference = window.open("http://www.spreadfirefox.com/",
   "PromoteFirefoxWindowName", "resizable,scrollbars,status");
    /* then create it. The new window will be created and
       will be brought on top of any other window. */
  }
  else
  {
    windowObjectReference.focus();
    /* else the window reference must exist and the window
       is not closed; therefore, we can bring it back on top of any other
       window with the focus() method. There would be no need to re-create
       the window or to reload the referenced resource. */
  };
}
</script>

<p><a
 href="http://www.spreadfirefox.com/"
 target="PromoteFirefoxWindowName"
 onclick="openFFPromotionPopup(); return false;" 
 title="This link will create a new window or will re-use an already opened one"
>Promote Firefox adoption</a></p>

What are the differences between json and simplejson Python modules?

Here's (a now outdated) comparison of Python json libraries:

Comparing JSON modules for Python (archive link)

Regardless of the results in this comparison you should use the standard library json if you are on Python 2.6. And.. might as well just use simplejson otherwise.

Insert NULL value into INT column

Just use the insert query and put the NULL keyword without quotes. That will work-

INSERT INTO `myDatabase`.`myTable` (`myColumn`) VALUES (NULL);

SpringMVC RequestMapping for GET parameters

This will get ALL parameters from the request. For Debugging purposes only:

@RequestMapping (value = "/promote", method = {RequestMethod.POST, RequestMethod.GET})
public ModelAndView renderPromotePage (HttpServletRequest request) {
    Map<String, String[]> parameters = request.getParameterMap();

    for(String key : parameters.keySet()) {
        System.out.println(key);
        String[] vals = parameters.get(key);
        for(String val : vals)
            System.out.println(" -> " + val);
    }

    ModelAndView mv = new ModelAndView();
    mv.setViewName("test");
    return mv;
}

What is the difference between single-quoted and double-quoted strings in PHP?

One thing:

It is very important to note that the line with the closing identifier of Heredoc must contain no other characters, except a semicolon (;). That means especially that the identifier may not be indented, and there may not be any spaces or tabs before or after the semicolon.

Example:

   $str = <<<EOD
Example of string
spanning multiple lines
using heredoc syntax.
EOD;

Build query string for System.Net.HttpClient get

Thanks to "Darin Dimitrov", This is the extension methods.

 public static partial class Ext
{
    public static Uri GetUriWithparameters(this Uri uri,Dictionary<string,string> queryParams = null,int port = -1)
    {
        var builder = new UriBuilder(uri);
        builder.Port = port;
        if(null != queryParams && 0 < queryParams.Count)
        {
            var query = HttpUtility.ParseQueryString(builder.Query);
            foreach(var item in queryParams)
            {
                query[item.Key] = item.Value;
            }
            builder.Query = query.ToString();
        }
        return builder.Uri;
    }

    public static string GetUriWithparameters(string uri,Dictionary<string,string> queryParams = null,int port = -1)
    {
        var builder = new UriBuilder(uri);
        builder.Port = port;
        if(null != queryParams && 0 < queryParams.Count)
        {
            var query = HttpUtility.ParseQueryString(builder.Query);
            foreach(var item in queryParams)
            {
                query[item.Key] = item.Value;
            }
            builder.Query = query.ToString();
        }
        return builder.Uri.ToString();
    }
}

vuejs update parent data from child component

Two-way binding has been deprecated in Vue 2.0 in favor of using a more event-driven architecture. In general, a child should not mutate its props. Rather, it should $emit events and let the parent respond to those events.

In your specific case, you could use a custom component with v-model. This is a special syntax which allows for something close to two-way binding, but is actually a shorthand for the event-driven architecture described above. You can read about it here -> https://vuejs.org/v2/guide/components.html#Form-Input-Components-using-Custom-Events.

Here's a simple example:

_x000D_

Vue.component('child', {_x000D_
  template: '#child',_x000D_
  _x000D_
  //The child has a prop named 'value'. v-model will automatically bind to this prop_x000D_
  props: ['value'],_x000D_
  methods: {_x000D_
    updateValue: function (value) {_x000D_
      this.$emit('input', value);_x000D_
    }_x000D_
  }_x000D_
});_x000D_
_x000D_
new Vue({_x000D_
  el: '#app',_x000D_
  data: {_x000D_
    parentValue: 'hello'_x000D_
  }_x000D_
});

_x000D_

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.13/vue.js"></script>_x000D_
_x000D_
<div id="app">_x000D_
  <p>Parent value: {{parentValue}}</p>_x000D_
  <child v-model="parentValue"></child>_x000D_
</div>_x000D_
_x000D_
<template id="child">_x000D_
   <input type="text" v-bind:value="value" v-on:input="updateValue($event.target.value)">_x000D_
</template>

_x000D_

The docs state that

<custom-input v-bind:value="something" v-on:input="something = arguments[0]"></custom-input>

is equivalent to

<custom-input v-model="something"></custom-input>

That is why the prop on the child needs to be named value, and why the child needs to $emit an event named input.

Convert a RGB Color Value to a Hexadecimal String

You can use

String hex = String.format("#%02x%02x%02x", r, g, b);

Use capital X's if you want your resulting hex-digits to be capitalized (#FFFFFF vs. #ffffff).

Populating a razor dropdownlist from a List<object> in MVC

Instead of a List<UserRole>, you can let your Model contain a SelectList<UserRole>. Also add a property SelectedUserRoleId to store... well... the selected UserRole's Id value.

Fill up the SelectList, then in your View use:

@Html.DropDownListFor(x => x.SelectedUserRoleId, x.UserRole)

and you should be fine.

Sorting Values of Set

Strings are sorted lexicographically. The behavior you're seeing is correct.

Define your own comparator to sort the strings however you prefer.

It would also work the way you're expecting (5 as the first element) if you changed your collections to Integer instead of using String.

How do I update a Tomcat webapp without restarting the entire service?

In conf directory of apache tomcat you can find context.xml file. In that edit tag as <Context reloadable="true">. this should solve the issue and you need not restart the server

What is the difference between public, private, and protected?

It is typically considered good practice to default to the lowest visibility required as this promotes data encapsulation and good interface design. When considering member variable and method visibility think about the role the member plays in the interaction with other objects.

If you "code to an interface rather than implementation" then it's usually pretty straightforward to make visibility decisions. In general, variables should be private or protected unless you have a good reason to expose them. Use public accessors (getters/setters) instead to limit and regulate access to a class's internals.

To use a car as an analogy, things like speed, gear, and direction would be private instance variables. You don't want the driver to directly manipulate things like air/fuel ratio. Instead, you expose a limited number of actions as public methods. The interface to a car might include methods such as accelerate(), deccelerate()/brake(), setGear(), turnLeft(), turnRight(), etc.

The driver doesn't know nor should he care how these actions are implemented by the car's internals, and exposing that functionality could be dangerous to the driver and others on the road. Hence the good practice of designing a public interface and encapsulating the data behind that interface.

This approach also allows you to alter and improve the implementation of the public methods in your class without breaking the interface's contract with client code. For example, you could improve the accelerate() method to be more fuel efficient, yet the usage of that method would remain the same; client code would require no changes but still reap the benefits of your efficiency improvement.

Edit: Since it seems you are still in the midst of learning object oriented concepts (which are much more difficult to master than any language's syntax), I highly recommend picking up a copy of PHP Objects, Patterns, and Practice by Matt Zandstra. This is the book that first taught me how to use OOP effectively, rather than just teaching me the syntax. I had learned the syntax years beforehand, but that was useless without understanding the "why" of OOP.

Mocking a method to throw an exception (moq), but otherwise act like the mocked object?

This is how I managed to do what I was trying to do:

[Test]
public void TransferHandlesDisconnect()
{
    // ... set up config here
    var methodTester = new Mock<Transfer>(configInfo);
    methodTester.CallBase = true;
    methodTester
        .Setup(m => 
            m.GetFile(
                It.IsAny<IFileConnection>(), 
                It.IsAny<string>(), 
                It.IsAny<string>()
            ))
        .Throws<System.IO.IOException>();

    methodTester.Object.TransferFiles("foo1", "foo2");
    Assert.IsTrue(methodTester.Object.Status == TransferStatus.TransferInterrupted);
}

If there is a problem with this method, I would like to know; the other answers suggest I am doing this wrong, but this was exactly what I was trying to do.

What is the purpose of willSet and didSet in Swift?

One thing where didSet is really handy is when you use outlets to add additional configuration.

@IBOutlet weak var loginOrSignupButton: UIButton! {
  didSet {
        let title = NSLocalizedString("signup_required_button")
        loginOrSignupButton.setTitle(title, for: .normal)
        loginOrSignupButton.setTitle(title, for: .highlighted)
  }

Accessing Object Memory Address

While it's true that id(object) gets the object's address in the default CPython implementation, this is generally useless... you can't do anything with the address from pure Python code.

The only time you would actually be able to use the address is from a C extension library... in which case it is trivial to get the object's address since Python objects are always passed around as C pointers.

How to parse float with two decimal places in javascript?

Solution for FormArray controllers

Initialize FormArray form Builder

  formInitilize() {
    this.Form = this._formBuilder.group({
      formArray: this._formBuilder.array([this.createForm()])
    });
  }

Create Form

  createForm() {
    return (this.Form = this._formBuilder.group({
      convertodecimal: ['']
    }));
  }

Set Form Values into Form Controller

  setFormvalues() {
    this.Form.setControl('formArray', this._formBuilder.array([]));
    const control = <FormArray>this.resourceBalanceForm.controls['formArray'];
    this.ListArrayValues.forEach((x) => {
      control.push(this.buildForm(x));
    });
  }

  private buildForm(x): FormGroup {
    const bindvalues= this._formBuilder.group({
      convertodecimal: x.ArrayCollection1? parseFloat(x.ArrayCollection1[0].name).toFixed(2) : '' // Option for array collection
// convertodecimal: x.number.toFixed(2)    --- option for two decimal value 
    });

    return bindvalues;
  }

What is the best way to uninstall gems from a rails3 project?

You must use 'gem uninstall gem_name' to uninstall a gem.

Note that if you installed the gem system-wide (ie. sudo bundle install) then you may need to specify the binary directory using the -n option, to ensure binaries belonging to the gem are removed. For example

sudo gem uninstall gem_name  -n /usr/lib/ruby/gems/1.9.1/bin

Create database from command line

Try:

sudo -u postgres psql -c 'create database test;'

How to select an item from a dropdown list using Selenium WebDriver with java?

WebElement select = driver.findElement(By.id("gender"));
List<WebElement> options = select.findElements(By.tagName("option"));
for (WebElement option : options) {
   if("Germany".equals(option.getText()))
       option.click();   
}

Concatenate two char* strings in a C program

strcat concats str2 onto str1

You'll get runtime errors because str1 is not being properly allocated for concatenation

Populating a ComboBox using C#

If you simply want to add it without creating a new class try this:

// WPF
<ComboBox Name="language" Loaded="language_Loaded" /> 


// C# code
private void language_Loaded(object sender, RoutedEventArgs e)
{
    List<String> language= new List<string>();
    language.Add("English");
    language.Add("Spanish");
    language.Add("ect"); 
    this.chartReviewComboxBox.ItemsSource = language;
}

I suggest an xml file with all your languages that you will support that way you do not have to be dependent on c# I would definitly create a class for languge like the above programmer suggest.

Prevent overwriting a file using cmd if exist

Use the FULL path to the folder in your If Not Exist code. Then you won't even have to CD anymore:

If Not Exist "C:\Documents and Settings\John\Start Menu\Programs\SoftWareFolder\"

PHP multiline string with PHP

You cannot run PHP code within a string like that. It just doesn't work. As well, when you're "out" of PHP code (?>), any text outside of the PHP blocks is considered output anyway, so there's no need for the echo statement.

If you do need to do multiline output from with a chunk of PHP code, consider using a HEREDOC:

<?php

$var = 'Howdy';

echo <<<EOL
This is output
And this is a new line
blah blah blah and this following $var will actually say Howdy as well

and now the output ends
EOL;

Finding square root without using sqrt function?

Here is a very awesome code to find sqrt and even faster than original sqrt function.

float InvSqrt (float x) 
{
    float xhalf = 0.5f*x;
    int i = *(int*)&x;
    i = 0x5f375a86 - (i>>1);
    x = *(float*)&i;
    x = x*(1.5f - xhalf*x*x);
    x = x*(1.5f - xhalf*x*x);
    x = x*(1.5f - xhalf*x*x);
    x=1/x;
    return x;
}

SQL Server Error : String or binary data would be truncated

This error is usually encountered when inserting a record in a table where one of the columns is a VARCHAR or CHAR data type and the length of the value being inserted is longer than the length of the column.

I am not satisfied how Microsoft decided to inform with this "dry" response message, without any point of where to look for the answer.

How does the bitwise complement operator (~ tilde) work?

This operation is a complement, not a negation.

Consider that ~0 = -1, and work from there.

The algorithm for negation is, "complement, increment".

Did you know? There is also "one's complement" where the inverse numbers are symmetrical, and it has both a 0 and a -0.

MySQL's now() +1 day

INSERT INTO `table` ( `data` , `date` ) VALUES('".$data."',NOW()+INTERVAL 1 DAY);

Programs & Examples On #Aspen

Remove all child nodes from a parent?

How to open link in new tab on html?

Programmatically trigger "select file" dialog box

Is it possible to have empty RequestParam values use the defaultValue?

Rotation of 3D vector?

How to make an HTTP get request with parameters

scroll image with continuous scrolling using marquee tag

Getting "net::ERR_BLOCKED_BY_CLIENT" error on some AJAX calls

How do you force a makefile to rebuild a target

How can I regenerate ios folder in React Native project?

How to fix warning from date() in PHP"

What is the difference between varchar and varchar2 in Oracle?

How to Install pip for python 3.7 on Ubuntu 18?

What is the difference between DSA and RSA?

Is it correct to use DIV inside FORM?

C++ display stack trace on exception

ExecuteNonQuery doesn't return results

How to keep footer at bottom of screen

How to correctly dismiss a DialogFragment?

Sending Arguments To Background Worker?

How does inline Javascript (in HTML) work?

Setting background images in JFrame

How do I register a .NET DLL file in the GAC?

How to delete migration files in Rails 3

Insert null/empty value in sql datetime column by default

How can I handle the warning of file_get_contents() function in PHP?

What, exactly, is needed for "margin: 0 auto;" to work?

Why is this rsync connection unexpectedly closed on Windows?

How to use random in BATCH script?

Invalid argument supplied for foreach()

flow 2 columns of text automatically with CSS

CSS image resize percentage of itself?

How do I create a GUI for a windows application using C++?

How do I add a library path in cmake?

How to find Google's IP address?

IntelliJ can't recognize JavaFX 11 with OpenJDK 11

How to get the seconds since epoch from the time + date output of gmtime()?

'uint32_t' does not name a type

How to load all modules in a folder?

Adding images or videos to iPhone Simulator

How to replace multiple patterns at once with sed?

How to create/read/write JSON files in Qt5

Remove part of string after "."

Javascript "Cannot read property 'length' of undefined" when checking a variable's length

Why?

Page vs Window in WPF?

Insert at first position of a list in Python

Error: "dictionary update sequence element #0 has length 1; 2 is required" on Django 1.4

How to pass 2D array (matrix) in a function in C?

How do I verify/check/test/validate my SSH passphrase?

java.lang.ClassNotFoundException: org.apache.log4j.Level

How to purge tomcat's cache when deploying a new .war file? Is there a config setting?

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

How to perform runtime type checking in Dart?

How to remove white space characters from a string in SQL Server

Sort hash by key, return hash in Ruby

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

Angular 4: InvalidPipeArgument: '[object Object]' for pipe 'AsyncPipe'

How do I get the directory of the PowerShell script I execute?

PHP: Return all dates between two dates in an array

Removing highcharts.com credits link

Set UILabel line spacing

Pandas split column of lists into multiple columns

link_to method and click event in Rails

Copy a table from one database to another in Postgres

html5 input for money/currency

AngularJs event to call after content is loaded

Find files in created between a date range

Find the least number of coins required that can make any change from 1 to 99 cents

How to create an array for JSON using PHP?

Hive: Filtering Data between Specified Dates when Date is a String

Angular 5 - Copy to clipboard

Disable cache for some images

How do I clone a github project to run locally?

Java generics: multiple generic parameters?

What does Ruby have that Python doesn't, and vice versa?

Getting mouse position in c#

CFLAGS vs CPPFLAGS

Repair all tables in one go

`@ts-expect-error`