Programs & Examples On #Jinternalframe

JInternalFrame is a lightweight Java Swing component that provides many of the features of a native frame, including dragging, closing, becoming an icon, resizing, title display, and support for a menu bar.

Creating SVG graphics using Javascript?

There are multiple libraries on SVG graphics using Javascript like: Snap, Raphael, D3. Or you can directly interface the SVG with plain javascript.

Currently all latest versions of the browsers support SVG v1.1. SVG v2.0 is in Working Draft and too early to use it.

This article shows how to interact with SVG using Javascript and has reference to links for browser support. Interfacing with SVG

How do I create and read a value from cookie?

I use the following functions, which I have written by taking the best I have found from various sources and weeded out some bugs or discrepancies.

The function setCookie does not have advanced options, just the simple stuff, but the code is easy to understand, which is always a plus:

function setCookie(name, value, daysToLive = 3650) { // 10 years default
  let cookie = name + "=" + encodeURIComponent(value);
  if (typeof daysToLive === "number") {
    cookie += "; max-age=" + (daysToLive * 24 * 60 * 60);
    document.cookie = cookie + ";path=/";
  }
}
function getCookie(name) {
  let cookieArr = document.cookie.split(";");
  for (let i = 0; i < cookieArr.length; i++) {
    let cookiePair = cookieArr[i].split("=");
    if (name == cookiePair[0].trim()) {
      return decodeURIComponent(cookiePair[1].trim());
    }
  }
  return undefined;
}
function deleteCookie(name) {
  setCookie(name, '', -1);
}

fatal: bad default revision 'HEAD'

just do an initial commit and the error will go away:

git commit -m "initial commit"

Which are more performant, CTE or temporary tables?

It depends.

First of all

What is a Common Table Expression?

A (non recursive) CTE is treated very similarly to other constructs that can also be used as inline table expressions in SQL Server. Derived tables, Views, and inline table valued functions. Note that whilst BOL says that a CTE "can be thought of as temporary result set" this is a purely logical description. More often than not it is not materlialized in its own right.

What is a temporary table?

This is a collection of rows stored on data pages in tempdb. The data pages may reside partially or entirely in memory. Additionally the temporary table may be indexed and have column statistics.

Test Data

CREATE TABLE T(A INT IDENTITY PRIMARY KEY, B INT , F CHAR(8000) NULL);

INSERT INTO T(B)
SELECT TOP (1000000)  0 + CAST(NEWID() AS BINARY(4))
FROM master..spt_values v1,
     master..spt_values v2;

Example 1

WITH CTE1 AS
(
SELECT A,
       ABS(B) AS Abs_B,
       F
FROM T
)
SELECT *
FROM CTE1
WHERE A = 780

Plan 1

Notice in the plan above there is no mention of CTE1. It just accesses the base tables directly and is treated the same as

SELECT A,
       ABS(B) AS Abs_B,
       F
FROM   T
WHERE  A = 780 

Rewriting by materializing the CTE into an intermediate temporary table here would be massively counter productive.

Materializing the CTE definition of

SELECT A,
       ABS(B) AS Abs_B,
       F
FROM T

Would involve copying about 8GB of data into a temporary table then there is still the overhead of selecting from it too.

Example 2

WITH CTE2
     AS (SELECT *,
                ROW_NUMBER() OVER (ORDER BY A) AS RN
         FROM   T
         WHERE  B % 100000 = 0)
SELECT *
FROM   CTE2 T1
       CROSS APPLY (SELECT TOP (1) *
                    FROM   CTE2 T2
                    WHERE  T2.A > T1.A
                    ORDER  BY T2.A) CA 

The above example takes about 4 minutes on my machine.

Only 15 rows of the 1,000,000 randomly generated values match the predicate but the expensive table scan happens 16 times to locate these.

enter image description here

This would be a good candidate for materializing the intermediate result. The equivalent temp table rewrite took 25 seconds.

INSERT INTO #T
SELECT *,
       ROW_NUMBER() OVER (ORDER BY A) AS RN
FROM   T
WHERE  B % 100000 = 0

SELECT *
FROM   #T T1
       CROSS APPLY (SELECT TOP (1) *
                    FROM   #T T2
                    WHERE  T2.A > T1.A
                    ORDER  BY T2.A) CA 

With Plan

Intermediate materialisation of part of a query into a temporary table can sometimes be useful even if it is only evaluated once - when it allows the rest of the query to be recompiled taking advantage of statistics on the materialized result. An example of this approach is in the SQL Cat article When To Break Down Complex Queries.

In some circumstances SQL Server will use a spool to cache an intermediate result, e.g. of a CTE, and avoid having to re-evaluate that sub tree. This is discussed in the (migrated) Connect item Provide a hint to force intermediate materialization of CTEs or derived tables. However no statistics are created on this and even if the number of spooled rows was to be hugely different from estimated is not possible for the in progress execution plan to dynamically adapt in response (at least in current versions. Adaptive Query Plans may become possible in the future).

Can I set max_retries for requests.request?

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

You can do this instead:

import requests
from requests.adapters import HTTPAdapter

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

How to send POST request in JSON using HTTPClient in Android?

In this answer I am using an example posted by Justin Grammens.

About JSON

JSON stands for JavaScript Object Notation. In JavaScript properties can be referenced both like this object1.name and like this object['name'];. The example from the article uses this bit of JSON.

The Parts
A fan object with email as a key and [email protected] as a value

{
  fan:
    {
      email : '[email protected]'
    }
}

So the object equivalent would be fan.email; or fan['email'];. Both would have the same value of '[email protected]'.

About HttpClient Request

The following is what our author used to make a HttpClient Request. I do not claim to be an expert at all this so if anyone has a better way to word some of the terminology feel free.

public static HttpResponse makeRequest(String path, Map params) throws Exception 
{
    //instantiates httpclient to make request
    DefaultHttpClient httpclient = new DefaultHttpClient();

    //url with the post data
    HttpPost httpost = new HttpPost(path);

    //convert parameters into JSON object
    JSONObject holder = getJsonObjectFromMap(params);

    //passes the results to a string builder/entity
    StringEntity se = new StringEntity(holder.toString());

    //sets the post request as the resulting string
    httpost.setEntity(se);
    //sets a request header so the page receving the request
    //will know what to do with it
    httpost.setHeader("Accept", "application/json");
    httpost.setHeader("Content-type", "application/json");

    //Handles what is returned from the page 
    ResponseHandler responseHandler = new BasicResponseHandler();
    return httpclient.execute(httpost, responseHandler);
}

Map

If you are not familiar with the Map data structure please take a look at the Java Map reference. In short, a map is similar to a dictionary or a hash.

private static JSONObject getJsonObjectFromMap(Map params) throws JSONException {

    //all the passed parameters from the post request
    //iterator used to loop through all the parameters
    //passed in the post request
    Iterator iter = params.entrySet().iterator();

    //Stores JSON
    JSONObject holder = new JSONObject();

    //using the earlier example your first entry would get email
    //and the inner while would get the value which would be '[email protected]' 
    //{ fan: { email : '[email protected]' } }

    //While there is another entry
    while (iter.hasNext()) 
    {
        //gets an entry in the params
        Map.Entry pairs = (Map.Entry)iter.next();

        //creates a key for Map
        String key = (String)pairs.getKey();

        //Create a new map
        Map m = (Map)pairs.getValue();   

        //object for storing Json
        JSONObject data = new JSONObject();

        //gets the value
        Iterator iter2 = m.entrySet().iterator();
        while (iter2.hasNext()) 
        {
            Map.Entry pairs2 = (Map.Entry)iter2.next();
            data.put((String)pairs2.getKey(), (String)pairs2.getValue());
        }

        //puts email and '[email protected]'  together in map
        holder.put(key, data);
    }
    return holder;
}

Please feel free to comment on any questions that arise about this post or if I have not made something clear or if I have not touched on something that your still confused about... etc whatever pops in your head really.

(I will take down if Justin Grammens does not approve. But if not then thanks Justin for being cool about it.)

Update

I just happend to get a comment about how to use the code and realized that there was a mistake in the return type. The method signature was set to return a string but in this case it wasnt returning anything. I changed the signature to HttpResponse and will refer you to this link on Getting Response Body of HttpResponse the path variable is the url and I updated to fix a mistake in the code.

How to decode a QR-code image in (preferably pure) Python?

You can try the following steps and code using qrtools:

  • Create a qrcode file, if not already existing

    • I used pyqrcode for doing this, which can be installed using pip install pyqrcode
    • And then use the code:

      >>> import pyqrcode
      >>> qr = pyqrcode.create("HORN O.K. PLEASE.")
      >>> qr.png("horn.png", scale=6)
      
  • Decode an existing qrcode file using qrtools

    • Install qrtools using sudo apt-get install python-qrtools
    • Now use the following code within your python prompt

      >>> import qrtools
      >>> qr = qrtools.QR()
      >>> qr.decode("horn.png")
      >>> print qr.data
      u'HORN O.K. PLEASE.'
      

Here is the complete code in a single run:

In [2]: import pyqrcode
In [3]: qr = pyqrcode.create("HORN O.K. PLEASE.")
In [4]: qr.png("horn.png", scale=6)
In [5]: import qrtools
In [6]: qr = qrtools.QR()
In [7]: qr.decode("horn.png")
Out[7]: True
In [8]: print qr.data
HORN O.K. PLEASE.

Caveats

  • You might need to install PyPNG using pip install pypng for using pyqrcode
  • In case you have PIL installed, you might get IOError: decoder zip not available. In that case, try uninstalling and reinstalling PIL using:

    pip uninstall PIL
    pip install PIL
    
  • If that doesn't work, try using Pillow instead

    pip uninstall PIL
    pip install pillow
    

What's the simplest way of detecting keyboard input in a script from the terminal?

Well, since the date of this question post, a Python library addressed this topic. pynput library, from Moses Palmer, is GREAT to catch keyboard and mouse events in a very simple way.

(mind the missing 'i' in pynput - I missed it too... ;-) )

javascript, for loop defines a dynamic variable name

I think you could do it by creating parameters in an object maybe?

var myObject = {}; for(var i=0;i<myArray.length;i++) {     myObject[ myArray[i] ]; } 

If you don't set them to anything, you'll just have an object with some parameters that are undefined. I'd have to write this myself to be sure though.

What's the best way to test SQL Server connection programmatically?

Look for an open listener on port 1433 (the default port). If you get any response after creating a tcp connection there, the server's probably up.

Nth max salary in Oracle

5th highest salary:

SELECT
    * 
FROM
    emp a 
WHERE 
    4 = (
        SELECT 
            COUNT(DISTINCT b.sal) 
        FROM 
            emp b 
        WHERE 
            a.sal < b.sal
    )

Replace 4 with any value of N.

Google Map API - Removing Markers

You can try this

    markers[markers.length-1].setMap(null);

Hope it works.

Redirecting exec output to a buffer or file

Since you look like you're going to be using this in a linux/cygwin environment, you want to use popen. It's like opening a file, only you'll get the executing programs stdout, so you can use your normal fscanf, fread etc.

How to remove focus without setting focus to another control?

You do not need to clear focus, just add this code where you want to focus

 time_statusTV.setFocusable(true);
 time_statusTV.requestFocus();
 InputMethodManager imm = (InputMethodManager)this.getSystemService(Service.INPUT_METHOD_SERVICE);
 imm.showSoftInput( time_statusTV, 0);

Docker-compose: node_modules not present in a volume after npm install succeeds

This happens because you have added your worker directory as a volume to your docker-compose.yml, as the volume is not mounted during the build.

When docker builds the image, the node_modules directory is created within the worker directory, and all the dependencies are installed there. Then on runtime the worker directory from outside docker is mounted into the docker instance (which does not have the installed node_modules), hiding the node_modules you just installed. You can verify this by removing the mounted volume from your docker-compose.yml.

A workaround is to use a data volume to store all the node_modules, as data volumes copy in the data from the built docker image before the worker directory is mounted. This can be done in the docker-compose.yml like this:

redis:
    image: redis
worker:
    build: ./worker
    command: npm start
    ports:
        - "9730:9730"
    volumes:
        - ./worker/:/worker/
        - /worker/node_modules
    links:
        - redis

I'm not entirely certain whether this imposes any issues for the portability of the image, but as it seems you are primarily using docker to provide a runtime environment, this should not be an issue.

If you want to read more about volumes, there is a nice user guide available here: https://docs.docker.com/userguide/dockervolumes/

EDIT: Docker has since changed it's syntax to require a leading ./ for mounting in files relative to the docker-compose.yml file.

Creating a recursive method for Palindrome

there's no code smaller than this:

public static boolean palindrome(String x){
    return (x.charAt(0) == x.charAt(x.length()-1)) && 
        (x.length()<4 || palindrome(x.substring(1, x.length()-1)));
}

if you want to check something:

public static boolean palindrome(String x){
    if(x==null || x.length()==0){
        throw new IllegalArgumentException("Not a valid string.");
    }
    return (x.charAt(0) == x.charAt(x.length()-1)) && 
        (x.length()<4 || palindrome(x.substring(1, x.length()-1)));
}

LOL B-]

SecurityError: Blocked a frame with origin from accessing a cross-origin frame

Same-origin policy

You can't access an <iframe> with different origin using JavaScript, it would be a huge security flaw if you could do it. For the same-origin policy browsers block scripts trying to access a frame with a different origin.

Origin is considered different if at least one of the following parts of the address isn't maintained:

protocol://hostname:port/...

Protocol, hostname and port must be the same of your domain if you want to access a frame.

NOTE: Internet Explorer is known to not strictly follow this rule, see here for details.

Examples

Here's what would happen trying to access the following URLs from http://www.example.com/home/index.html

URL                                             RESULT 
http://www.example.com/home/other.html       -> Success 
http://www.example.com/dir/inner/another.php -> Success 
http://www.example.com:80                    -> Success (default port for HTTP) 
http://www.example.com:2251                  -> Failure: different port 
http://data.example.com/dir/other.html       -> Failure: different hostname 
https://www.example.com/home/index.html:80   -> Failure: different protocol
ftp://www.example.com:21                     -> Failure: different protocol & port 
https://google.com/search?q=james+bond       -> Failure: different protocol, port & hostname 

Workaround

Even though same-origin policy blocks scripts from accessing the content of sites with a different origin, if you own both the pages, you can work around this problem using window.postMessage and its relative message event to send messages between the two pages, like this:

  • In your main page:

    const frame = document.getElementById('your-frame-id');
    frame.contentWindow.postMessage(/*any variable or object here*/, 'http://your-second-site.com');
    

    The second argument to postMessage() can be '*' to indicate no preference about the origin of the destination. A target origin should always be provided when possible, to avoid disclosing the data you send to any other site.

  • In your <iframe> (contained in the main page):

    window.addEventListener('message', event => {
        // IMPORTANT: check the origin of the data! 
        if (event.origin.startsWith('http://your-first-site.com')) { 
            // The data was sent from your site.
            // Data sent with postMessage is stored in event.data:
            console.log(event.data); 
        } else {
            // The data was NOT sent from your site! 
            // Be careful! Do not use it. This else branch is
            // here just for clarity, you usually shouldn't need it.
            return; 
        } 
    }); 
    

This method can be applied in both directions, creating a listener in the main page too, and receiving responses from the frame. The same logic can also be implemented in pop-ups and basically any new window generated by the main page (e.g. using window.open()) as well, without any difference.

Disabling same-origin policy in your browser

There already are some good answers about this topic (I just found them googling), so, for the browsers where this is possible, I'll link the relative answer. However, please remember that disabling the same-origin policy will only affect your browser. Also, running a browser with same-origin security settings disabled grants any website access to cross-origin resources, so it's very unsafe and should NEVER be done if you do not know exactly what you are doing (e.g. development purposes).

Keras model.summary() result - Understanding the # of Parameters

For Dense Layers:

output_size * (input_size + 1) == number_parameters 

For Conv Layers:

output_channels * (input_channels * window_size + 1) == number_parameters

Consider following example,

model = Sequential([
Conv2D(32, (3, 3), activation='relu', input_shape=input_shape),
Conv2D(64, (3, 3), activation='relu'),
Conv2D(128, (3, 3), activation='relu'),
Dense(num_classes, activation='softmax')
])

model.summary()
_________________________________________________________________
Layer (type)                 Output Shape              Param #   
=================================================================
conv2d_1 (Conv2D)            (None, 222, 222, 32)      896       
_________________________________________________________________
conv2d_2 (Conv2D)            (None, 220, 220, 64)      18496     
_________________________________________________________________
conv2d_3 (Conv2D)            (None, 218, 218, 128)     73856     
_________________________________________________________________
dense_9 (Dense)              (None, 218, 218, 10)      1290      
=================================================================

Calculating params,

assert 32 * (3 * (3*3) + 1) == 896
assert 64 * (32 * (3*3) + 1) == 18496
assert 128 * (64 * (3*3) + 1) == 73856
assert num_classes * (128 + 1) == 1290

How to change value of ArrayList element in java

Use the set method to replace the old value with a new one.

list.set( 2, "New" );

Extract / Identify Tables from PDF python

You should definitely have a look at this answer of mine:

and also have a look at all the links included therein.

Tabula/TabulaPDF is currently the best table extraction tool that is available for PDF scraping.

Evaluate if list is empty JSTL

There's also the function tags, a bit more flexible:

<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<c:if test="${fn:length(list) > 0}">

And here's the tag documentation.

How do I change a tab background color when using TabLayout?

As I found best and suitable option for me and it will work with animation too.

You can use indicator it self as a background.

You can set app:tabIndicatorGravity="stretch" attribute to use as background.

Example:

   <android.support.design.widget.TabLayout
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabIndicatorGravity="stretch"
        app:tabSelectedTextColor="@color/white"
        app:tabTextColor="@color/colorAccent">

        <android.support.design.widget.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Chef" />


        <android.support.design.widget.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="User" />

    </android.support.design.widget.TabLayout>

Hope it will helps you.

moment.js get current time in milliseconds?

You can just get the individual time components and calculate the total. You seem to be expecting Moment to already have this feature neatly packaged up for you, but it doesn't. I doubt it's something that people have a need for very often.

Example:

_x000D_
_x000D_
var m = moment();_x000D_
_x000D_
var ms = m.milliseconds() + 1000 * (m.seconds() + 60 * (m.minutes() + 60 * m.hours()));_x000D_
_x000D_
console.log(ms);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>
_x000D_
_x000D_
_x000D_

pull access denied repository does not exist or may require docker login

I had the same issue when working with docker-composer. In my case it was an Amazon AWS ECR private registry. It seems to be a bug in docker-compose

https://github.com/docker/compose/issues/1622#issuecomment-162988389

After adding the full path "myrepo/myimage" to docker compose yaml

image: xxxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/myrepo:myimage

it was all fine.

Parser Error Message: Could not load type 'TestMvcApplication.MvcApplication'

I had the same error and none of your solutions helped. I think my problem was simply the name that I had chosen for the project. I had named my project 'interface' which when I got the parse error it said that it couldn't load:

Line 1: <%@ Application Codebehind="Global.asax.cs" Inherits="@interface.MvcApplication" Language="C#" %>

Where there was an '@' sign for some reason. I am guessing the word 'interface' is reserved for something else and it added the @ symbol but that obviously broke something. I deleted the project and made a new one with a different name with no problems.

Trim a string in C

#include "stdafx.h"
#include <string.h>
#include <ctype.h>

char* trim(char* input);


int _tmain(int argc, _TCHAR* argv[])
{
    char sz1[]="  MQRFH  ";
    char sz2[]=" MQRFH";
    char sz3[]="  MQR FH";
    char sz4[]="MQRFH  ";
    char sz5[]="MQRFH";
    char sz6[]="M";
    char sz7[]="M ";
    char sz8[]=" M";
    char sz9[]="";
    char sz10[]="        ";

    printf("sz1:[%s] %d\n",trim(sz1), strlen(sz1));
    printf("sz2:[%s] %d\n",trim(sz2), strlen(sz2));
    printf("sz3:[%s] %d\n",trim(sz3), strlen(sz3));
    printf("sz4:[%s] %d\n",trim(sz4), strlen(sz4));
    printf("sz5:[%s] %d\n",trim(sz5), strlen(sz5));
    printf("sz6:[%s] %d\n",trim(sz6), strlen(sz6));
    printf("sz7:[%s] %d\n",trim(sz7), strlen(sz7));
    printf("sz8:[%s] %d\n",trim(sz8), strlen(sz8));
    printf("sz9:[%s] %d\n",trim(sz9), strlen(sz9));
    printf("sz10:[%s] %d\n",trim(sz10), strlen(sz10));

    return 0;
}

char *ltrim(char *s) 
{     
    while(isspace(*s)) s++;     
    return s; 
}  

char *rtrim(char *s) 
{     
    char* back;
    int len = strlen(s);

    if(len == 0)
        return(s); 

    back = s + len;     
    while(isspace(*--back));     
    *(back+1) = '\0';     
    return s; 
}  

char *trim(char *s) 
{     
    return rtrim(ltrim(s));  
} 

Output:

sz1:[MQRFH] 9
sz2:[MQRFH] 6
sz3:[MQR FH] 8
sz4:[MQRFH] 7
sz5:[MQRFH] 5
sz6:[M] 1
sz7:[M] 2
sz8:[M] 2
sz9:[] 0
sz10:[] 8

Creating a Zoom Effect on an image on hover using CSS?

Simply:

.grow { transition: all .2s ease-in-out; }

This will allow the element to assign an animation via css.

.grow:hover { transform: scale(1.1); }

This will make it grow!

How to use regex in file find

Just little elaboration of regex for search a directory and file

Find a directroy with name like book

find . -name "*book*" -type d

Find a file with name like book word

find . -name "*book*" -type f

How to enter in a Docker container already running with a new TTY

The "nsinit" way is:

install nsinit

git clone [email protected]:dotcloud/docker.git
cd docker
make shell

from inside the container:

go install github.com/dotcloud/docker/pkg/libcontainer/nsinit/nsinit

from outside:

docker cp id_docker_container:/go/bin/nsinit /root/

use it

cd /var/lib/docker/execdriver/native/<container_id>/
nsinit exec bash

How do I check if a C++ string is an int?

Here is another solution.

try
{
  (void) std::stoi(myString); //cast to void to ignore the return value   
  //Success! myString contained an integer
} 
catch (const std::logic_error &e)
{   
  //Failure! myString did not contain an integer
}

How can I implement a theme from bootswatch or wrapbootstrap in an MVC 5 project?

Bootswatch is a good alternative, but you can also find multiple types of free templates made for ASP.NET MVC that use MDBootstrap (a front-end framework built on top of Bootstrap) here:

ASP.NET MVC MDB Templates

How can I generate Unix timestamps?

nawk:

$ nawk 'BEGIN{print srand()}'
  • Works even on old versions of Solaris and probably other UNIX systems, where '''date +%s''' isn't implemented
  • Doesn't work on Linux and other distros where the posix tools have been replaced with the GNU versions (nawk -> gawk etc.)
  • Pretty unintuitive but definitelly amusing :-)

Comment shortcut Android Studio

For Line Comment: Ctrl + /

For Block Comment: Ctrl + Shift + /

Run a .bat file using python code

Replace \ with / in the path

import os
os.system("D:/xxx1/xxx2XMLnew/otr.bat ")

How do I get specific properties with Get-AdUser

using select-object for example:

Get-ADUser -Filter * -SearchBase 'OU=Users & Computers, DC=aaaaaaa, DC=com' -Properties DisplayName | select -expand displayname | Export-CSV "ADUsers.csv" 

What's the net::ERR_HTTP2_PROTOCOL_ERROR about?

By default nginx limits upload size to 1MB.

With client_max_body_size you can set your own limit, as in

location /uploads {
    ...
    client_max_body_size 100M;
} 

You can set this setting also on the http or server block instead (See here).

This fixed my issue with net::ERR_HTTP2_PROTOCOL_ERROR

How to show Alert Message like "successfully Inserted" after inserting to DB using ASp.net MVC3

Personally I'd go with AJAX.

If you cannot switch to @Ajax... helpers, I suggest you to add a couple of properties in your model

public bool TriggerOnLoad { get; set; }
public string TriggerOnLoadMessage { get; set: }

Change your view to a strongly typed Model via

@using MyModel

Before returning the View, in case of successfull creation do something like

MyModel model = new MyModel();
model.TriggerOnLoad = true;
model.TriggerOnLoadMessage = "Object successfully created!";
return View ("Add", model);

then in your view, add this

@{
   if (model.TriggerOnLoad) {
   <text>
   <script type="text/javascript">
     alert('@Model.TriggerOnLoadMessage');
   </script>
   </text>
   }
}

Of course inside the tag you can choose to do anything you want, event declare a jQuery ready function:

$(document).ready(function () {
   alert('@Model.TriggerOnLoadMessage');
});

Please remember to reset the Model properties upon successfully alert emission.

Another nice thing about MVC is that you can actually define an EditorTemplate for all this, and then use it in your view via:

@Html.EditorFor (m => m.TriggerOnLoadMessage)

But in case you want to build up such a thing, maybe it's better to define your own C# class:

class ClientMessageNotification {
    public bool TriggerOnLoad { get; set; }
    public string TriggerOnLoadMessage { get; set: }
}

and add a ClientMessageNotification property in your model. Then write EditorTemplate / DisplayTemplate for the ClientMessageNotification class and you're done. Nice, clean, and reusable.

How to center div vertically inside of absolutely positioned parent div

Center vertically and horizontally:

.parent{
  height: 100%;
  position: absolute;
  width: 100%;
  top: 0;
  left: 0;
}
.c{
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  transform: translateY(-50%);
}

Bootstrap 3 Navbar with Logo

Add the following to the .navbar-brand class

.navbar-brand
{
  padding: 0px; // this allows the image to occupy all the padding space of the navbar--brand
}

.navbar-brand > img
{
   height: 100%; // set height to occupy full height space on the navbar-brand
   width: auto; // width should be auto to allow img to scale accordingly
   max-height: 100%; // optional
   mrgin: 0 auto; // optional
}

Run PHP Task Asynchronously

If it just a question of providing expensive tasks, in case of php-fpm is supported, why not to use fastcgi_finish_request() function?

This function flushes all response data to the client and finishes the request. This allows for time consuming tasks to be performed without leaving the connection to the client open.

You don't really use asynchronicity in this way:

  1. Make all your main code first.
  2. Execute fastcgi_finish_request().
  3. Make all heavy stuff.

Once again php-fpm is needed.

What is the difference between C# and .NET?

C# does not have a seperate runtime library. It uses .NET as a runtime library.

How do you get the current text contents of a QComboBox?

PyQt4 can be forced to use a new API in which QString is automatically converted to and from a Python object:

import sip
sip.setapi('QString', 2)

With this API, QtCore.QString class is no longer available and self.ui.comboBox.currentText() will return a Python string or unicode object.

See Selecting Incompatible APIs from the doc.

Setting user agent of a java URLConnection

Off hand, setting the http.agent system property to "" might do the trick (I don't have the code in front of me).

You might get away with:

 System.setProperty("http.agent", "");

but that might require a race between you and initialisation of the URL protocol handler, if it caches the value at startup (actually, I don't think it does).

The property can also be set through JNLP files (available to applets from 6u10) and on the command line:

-Dhttp.agent=

Or for wrapper commands:

-J-Dhttp.agent=

Eloquent - where not equal to

Use where with a != operator in combination with whereNull

Code::where('to_be_used_by_user_id', '!=' , 2)->orWhereNull('to_be_used_by_user_id')->get()

Java: Multiple class declarations in one file

No. You can't. But it is very possible in Scala:

class Foo {val bar = "a"}
class Bar {val foo = "b"}

Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop

Another way is to use a copy of your arrayList just for iteration:

List<Object> l = ...
    
List<Object> iterationList = ImmutableList.copyOf(l);
    
for (Object curr : iterationList) {
    if (condition(curr)) {
        l.remove(curr);
    }
}

VBA Date as integer

Public SUB test()
    Dim mdate As Date
    mdate = now()
    MsgBox (Round(CDbl(mdate), 0))
End SUB

React Native Responsive Font Size

You can use something like this.

var {height, width} = Dimensions.get('window'); var textFontSize = width * 0.03;

inputText: {
    color : TEXT_COLOR_PRIMARY,
    width: '80%',
    fontSize: textFontSize
}

Hope this helps without installing any third party libraries.

Zero-pad digits in string

Solution using str_pad:

str_pad($digit,2,'0',STR_PAD_LEFT);

Benchmark on php 5.3

Result str_pad : 0.286863088608

Result sprintf : 0.234171152115

Code:

$start = microtime(true);
for ($i=0;$i<100000;$i++) {
    str_pad(9,2,'0',STR_PAD_LEFT);
    str_pad(15,2,'0',STR_PAD_LEFT);
    str_pad(100,2,'0',STR_PAD_LEFT);
}
$end = microtime(true);
echo "Result str_pad : ",($end-$start),"\n";

$start = microtime(true);
for ($i=0;$i<100000;$i++) {
    sprintf("%02d", 9);
    sprintf("%02d", 15);
    sprintf("%02d", 100);
}
$end = microtime(true);
echo "Result sprintf : ",($end-$start),"\n";

Visual Studio 2017 error: Unable to start program, An operation is not legal in the current state

Another solution you can try that worked for me when I received this error is to clean the solution, then do a rebuild. As the other solutions did not help me, I thought this might help someone else in the same boat.

How to pass ArrayList of Objects from one to another activity using Intent in android?

I had the exact same question and while still hassling with the Parcelable, I found out that the static variables are not such a bad idea for the task.

You can simply create a

public static ArrayList<Parliament> myObjects = .. 

and use it from elsewhere via MyRefActivity.myObjects

I was not sure about what public static variables imply in the context of an application with activities. If you also have doubts about either this or on performance aspects of this approach, refer to:

Cheers.

How do I link a JavaScript file to a HTML file?

You can add script tags in your HTML document, ideally inside the which points to your javascript files. Order of the script tags are important. Load the jQuery before your script files if you want to use jQuery from your script.

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script type="text/javascript" src="relative/path/to/your/javascript.js"></script>

Then in your javascript file you can refer to jQuery either using $ sign or jQuery. Example:

jQuery.each(arr, function(i) { console.log(i); }); 

How to remove part of a string?

assuming 11223344 is not constant

$string="REGISTER 11223344 here";
$s = explode(" ",$string);
unset($s[1]);
$s = implode(" ",$s);
print "$s\n";

How to get access to raw resources that I put in res folder?

TextView txtvw = (TextView)findViewById(R.id.TextView01);
        txtvw.setText(readTxt());

 private String readTxt()
    {
    InputStream raw = getResources().openRawResource(R.raw.hello);

    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

    int i;
    try
    {
        i = raw.read();
        while (i != -1)
        {
            byteArrayOutputStream.write(i);
            i = raw.read();
        }
        raw.close();
    }
    catch (IOException e)
    {
        // TODO Auto-generated catch block

        e.printStackTrace();
    }


    return byteArrayOutputStream.toString();

}

TextView01:: txtview in linearlayout hello:: .txt file in res/raw folder (u can access ny othr folder as wel)

Ist 2 lines are 2 written in onCreate() method

rest is to be written in class extending Activity!!

Xcode Objective-C | iOS: delay function / NSTimer help?

A slightly less verbose way is to use the performSelector: withObject: afterDelay: which sets up the NSTimer object for you and can be easily cancelled

So continuing with the previous example this would be

[self performSelector:@selector(goToSecondButton) withObject:nil afterDelay:.06];

More info in the doc

Tomcat 8 Maven Plugin for Java 8

Yes you can,

In your pom.xml, add the tomcat plugin. (You can use this for both Tomcat 7 and 8):

pom.xml

<!-- Tomcat plugin -->  
<plugin>  
 <groupId>org.apache.tomcat.maven</groupId>  
 <artifactId>tomcat7-maven-plugin</artifactId>  
 <version>2.2</version>  
 <configuration>  
  <url>http:// localhost:8080/manager/text</url>  
  <server>TomcatServer</server>    *(From maven > settings.xml)*
  <username>*yourtomcatusername*</username>  
  <password>*yourtomcatpassword*</password>   
 </configuration>   
</plugin>   

tomcat-users.xml

<tomcat-users>
    <role rolename="manager-gui"/>  
        <role rolename="manager-script"/>   
        <user username="admin" password="password" roles="manager-gui,manager-script" />  
</tomcat-users>

settings.xml (maven > conf)

<servers>  
    <server>
       <id>TomcatServer</id>
       <username>admin</username>
       <password>password</password>
    </server>
</servers>  

* deploy/re-deploy

mvn tomcat7:deploy OR mvn tomcat7:redeploy

Tried this on (Both Ubuntu and Windows 8/10):
* Jdk 7 & Tomcat 7
* Jdk 7 & Tomcat 8
* Jdk 8 & Tomcat 7
* Jdk 8 & Tomcat 8
* Jdk 8 & Tomcat 9

Tested on Both Jdk 7/8 & Tomcat 7/8. (Works with Tomcat 8.5 and 9)

Note:
Tomcat manager should be running or properly setup, before you can use it with maven.

Good Luck!

How can I get the line number which threw exception?

I added an extension to Exception which returns the line, column, method, filename and message:

public static class Extensions
{
    public static string ExceptionInfo(this Exception exception)
    {

        StackFrame stackFrame = (new StackTrace(exception, true)).GetFrame(0);
        return string.Format("At line {0} column {1} in {2}: {3} {4}{3}{5}  ",
           stackFrame.GetFileLineNumber(), stackFrame.GetFileColumnNumber(),
           stackFrame.GetMethod(), Environment.NewLine, stackFrame.GetFileName(),
           exception.Message);

    }
}

Finding the direction of scrolling in a UIScrollView?

- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
NSLog(@"px %f py %f",velocity.x,velocity.y);}

Use this delegate method of scrollview.

If y co-ordinate of velocity is +ve scroll view scrolls downwards and if it is -ve scrollview scrolls upwards. Similarly left and right scroll can be detected using x co-ordinate.

StringBuilder vs String concatenation in toString() in Java

In most cases, you won't see an actual difference between the two approaches, but it's easy to construct a worst case scenario like this one:

public class Main
{
    public static void main(String[] args)
    {
        long now = System.currentTimeMillis();
        slow();
        System.out.println("slow elapsed " + (System.currentTimeMillis() - now) + " ms");

        now = System.currentTimeMillis();
        fast();
        System.out.println("fast elapsed " + (System.currentTimeMillis() - now) + " ms");
    }

    private static void fast()
    {
        StringBuilder s = new StringBuilder();
        for(int i=0;i<100000;i++)
            s.append("*");      
    }

    private static void slow()
    {
        String s = "";
        for(int i=0;i<100000;i++)
            s+="*";
    }
}

The output is:

slow elapsed 11741 ms
fast elapsed 7 ms

The problem is that to += append to a string reconstructs a new string, so it costs something linear to the length of your strings (sum of both).

So - to your question:

The second approach would be faster, but it's less readable and harder to maintain. As I said, in your specific case you would probably not see the difference.

How to pass a form input value into a JavaScript function

Give your inputs names it will make it easier

<form>
<input type="text" id="formValueId" name="valueId"/>
<input type="button" onclick="foo(this.form.valueId.value)"/>
</form>

UPDATE:

If you give your button an id things can be even easier:

<form>
<input type="text" id="formValueId" name="valueId"/>
<input type="button" id="theButton"/>
</form>

Javascript:

var button = document.getElementById("theButton"),
value =  button.form.valueId.value;
button.onclick = function() {
    foo(value);
}

"React.Children.only expected to receive a single React element child" error when putting <Image> and <TouchableHighlight> in a <View>

just after TouchableWithoutFeedback or <TouchableHighlight> insert a <View> this way you won't get this error. why is that then @Pedram answer or other answers explains enough.

OR condition in Regex

A classic "or" would be |. For example, ab|de would match either side of the expression.

However, for something like your case you might want to use the ? quantifier, which will match the previous expression exactly 0 or 1 times (1 times preferred; i.e. it's a "greedy" match). Another (probably more relyable) alternative would be using a custom character group:

\d+\s+[A-Z\s]+\s+[A-Z][A-Za-z]+

This pattern will match:

  • \d+: One or more numbers.
  • \s+: One or more whitespaces.
  • [A-Z\s]+: One or more uppercase characters or space characters
  • \s+: One or more whitespaces.
  • [A-Z][A-Za-z\s]+: An uppercase character followed by at least one more character (uppercase or lowercase) or whitespaces.

If you'd like a more static check, e.g. indeed only match ABC and A ABC, then you can combine a (non-matching) group and define the alternatives inside (to limit the scope):

\d (?:ABC|A ABC) Street

Or another alternative using a quantifier:

\d (?:A )?ABC Street

Difference between Role and GrantedAuthority in Spring Security

Another way to understand the relationship between these concepts is to interpret a ROLE as a container of Authorities.

Authorities are fine-grained permissions targeting a specific action coupled sometimes with specific data scope or context. For instance, Read, Write, Manage, can represent various levels of permissions to a given scope of information.

Also, authorities are enforced deep in the processing flow of a request while ROLE are filtered by request filter way before reaching the Controller. Best practices prescribe implementing the authorities enforcement past the Controller in the business layer.

On the other hand, ROLES are coarse grained representation of an set of permissions. A ROLE_READER would only have Read or View authority while a ROLE_EDITOR would have both Read and Write. Roles are mainly used for a first screening at the outskirt of the request processing such as http. ... .antMatcher(...).hasRole(ROLE_MANAGER)

The Authorities being enforced deep in the request's process flow allows a finer grained application of the permission. For instance, a user may have Read Write permission to first level a resource but only Read to a sub-resource. Having a ROLE_READER would restrain his right to edit the first level resource as he needs the Write permission to edit this resource but a @PreAuthorize interceptor could block his tentative to edit the sub-resource.

Jake

How to show live preview in a small popup of linked page on mouse over on link?

Another way is to use a website thumbnail/link preview service LinkPeek (even happens to show a screenshot of StackOverflow as a demo right now), URL2PNG, Browshot, Websnapr, or an alternative.

Setting the correct PATH for Eclipse

Eclipse folder has an initialization file which is used by eclipse on launch/Double click it is named as eclipse.ini. Add the following lines in eclipse.ini file. Where the vm defines the path of JVM with which we want eclipse to use.

-vm
C:\Program Files\Java\jdk1.8\bin\javaw.exe

Make sure you have add the above lines separately and above the following line

--launcher.appendVmargs
-vmargs

How can I transition height: 0; to height: auto; using CSS?

I have not read everything in detail but I have had this problem recently and I did what follows:

div.class{
   min-height:1%;
   max-height:200px;
   -webkit-transition: all 0.5s ease;
   -moz-transition: all 0.5s ease;
   -o-transition: all 0.5s ease;
   -webkit-transition: all 0.5s ease;
   transition: all 0.5s ease;
   overflow:hidden;
}

div.class:hover{
   min-height:100%;
   max-height:3000px;
}

This allows you to have a div that at first shows content up to 200px height and on hover it's size becomes at least as high as the whole content of the div. The Div does not become 3000px but 3000px is the limit that I am imposing. Make sure to have the transition on the non :hover, otherwise you might get some strange rendering. In this way the :hover inherits from the non :hover.

Transition does not work form px to % or to auto. You need to use same unit of measure. This works fine for me. Using HTML5 makes it perfect....

Remember that there is always a work around... ; )

Hope someone finds this useful

How to move from one fragment to another fragment on click of an ImageView in Android?

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_profile, container, false);
    notification = (ImageView)v.findViewById(R.id.notification);

    notification.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            FragmentTransaction fr = getFragmentManager().beginTransaction();
            fr.replace(R.id.container,new NotificationFragment());
            fr.commit();
        }
    });

    return v;
}

NULL or BLANK fields (ORACLE)

SELECT COUNT (COL_NAME) 
FROM TABLE 
WHERE TRIM (COL_NAME) IS NULL 
or COL_NAME='NULL'

Angular2 set value for formGroup

You can use form.get to get the specific control object and use setValue

this.form.get(<formControlName>).setValue(<newValue>);

MySQL command line client for Windows

mysql.exe can do just that....

To connect,

mysql -u root -p (press enter)

It should prompt you to enter root password (u = username, p = password)

Then you can use SQL database commands to do pretty much anything....

add string to String array

As many of the answer suggesting better solution is to use ArrayList. ArrayList size is not fixed and it is easily manageable.

It is resizable-array implementation of the List interface. Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, this class provides methods to manipulate the size of the array that is used internally to store the list.

Each ArrayList instance has a capacity. The capacity is the size of the array used to store the elements in the list. It is always at least as large as the list size. As elements are added to an ArrayList, its capacity grows automatically.

Note that this implementation is not synchronized.

ArrayList<String> scripts = new ArrayList<String>();
scripts.add("test1");
scripts.add("test2");
scripts.add("test3");

Can anyone explain what JSONP is, in layman terms?

Say you had some URL that gave you JSON data like:

{'field': 'value'}

...and you had a similar URL except it used JSONP, to which you passed the callback function name 'myCallback' (usually done by giving it a query parameter called 'callback', e.g. http://example.com/dataSource?callback=myCallback). Then it would return:

myCallback({'field':'value'})

...which is not just an object, but is actually code that can be executed. So if you define a function elsewhere in your page called myFunction and execute this script, it will be called with the data from the URL.

The cool thing about this is: you can create a script tag and use your URL (complete with callback parameter) as the src attribute, and the browser will run it. That means you can get around the 'same-origin' security policy (because browsers allow you to run script tags from sources other than the domain of the page).

This is what jQuery does when you make an ajax request (using .ajax with 'jsonp' as the value for the dataType property). E.g.

$.ajax({
  url: 'http://example.com/datasource',
  dataType: 'jsonp',
  success: function(data) {
    // your code to handle data here
  }
});

Here, jQuery takes care of the callback function name and query parameter - making the API identical to other ajax calls. But unlike other types of ajax requests, as mentioned, you're not restricted to getting data from the same origin as your page.

What is a good pattern for using a Global Mutex in C#?

A global Mutex is not only to ensure to have only one instance of an application. I personally prefer using Microsoft.VisualBasic to ensure single instance application like described in What is the correct way to create a single-instance WPF application? (Dale Ragan answer)... I found that's easier to pass arguments received on new application startup to the initial single instance application.

But regarding some previous code in this thread, I would prefer to not create a Mutex each time I want to have a lock on it. It could be fine for a single instance application but in other usage it appears to me has overkill.

That's why I suggest this implementation instead:

Usage:

static MutexGlobal _globalMutex = null;
static MutexGlobal GlobalMutexAccessEMTP
{
    get
    {
        if (_globalMutex == null)
        {
            _globalMutex = new MutexGlobal();
        }
        return _globalMutex;
    }
}

using (GlobalMutexAccessEMTP.GetAwaiter())
{
    ...
}   

Mutex Global Wrapper:

using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Security.AccessControl;
using System.Security.Principal;
using System.Threading;

namespace HQ.Util.General.Threading
{
    public class MutexGlobal : IDisposable
    {
        // ************************************************************************
        public string Name { get; private set; }
        internal Mutex Mutex { get; private set; }
        public int DefaultTimeOut { get; set; }
        public Func<int, bool> FuncTimeOutRetry { get; set; }

        // ************************************************************************
        public static MutexGlobal GetApplicationMutex(int defaultTimeOut = Timeout.Infinite)
        {
            return new MutexGlobal(defaultTimeOut, ((GuidAttribute)Assembly.GetExecutingAssembly().GetCustomAttributes(typeof(GuidAttribute), false).GetValue(0)).Value);
        }

        // ************************************************************************
        public MutexGlobal(int defaultTimeOut = Timeout.Infinite, string specificName = null)
        {
            try
            {
                if (string.IsNullOrEmpty(specificName))
                {
                    Name = Guid.NewGuid().ToString();
                }
                else
                {
                    Name = specificName;
                }

                Name = string.Format("Global\\{{{0}}}", Name);

                DefaultTimeOut = defaultTimeOut;

                FuncTimeOutRetry = DefaultFuncTimeOutRetry;

                var allowEveryoneRule = new MutexAccessRule(new SecurityIdentifier(WellKnownSidType.WorldSid, null), MutexRights.FullControl, AccessControlType.Allow);
                var securitySettings = new MutexSecurity();
                securitySettings.AddAccessRule(allowEveryoneRule);

                Mutex = new Mutex(false, Name, out bool createdNew, securitySettings);

                if (Mutex == null)
                {
                    throw new Exception($"Unable to create mutex: {Name}");
                }
            }
            catch (Exception ex)
            {
                Log.Log.Instance.AddEntry(Log.LogType.LogException, $"Unable to create Mutex: {Name}", ex);
                throw;
            }
        }

        // ************************************************************************
        /// <summary>
        /// 
        /// </summary>
        /// <param name="timeOut"></param>
        /// <returns></returns>
        public MutexGlobalAwaiter GetAwaiter(int timeOut)
        {
            return new MutexGlobalAwaiter(this, timeOut);
        }

        // ************************************************************************
        /// <summary>
        /// 
        /// </summary>
        /// <param name="timeOut"></param>
        /// <returns></returns>
        public MutexGlobalAwaiter GetAwaiter()
        {
            return new MutexGlobalAwaiter(this, DefaultTimeOut);
        }

        // ************************************************************************
        /// <summary>
        /// This method could either throw any user specific exception or return 
        /// true to retry. Otherwise, retruning false will let the thread continue
        /// and you should verify the state of MutexGlobalAwaiter.HasTimedOut to 
        /// take proper action depending on timeout or not. 
        /// </summary>
        /// <param name="timeOutUsed"></param>
        /// <returns></returns>
        private bool DefaultFuncTimeOutRetry(int timeOutUsed)
        {
            // throw new TimeoutException($"Mutex {Name} timed out {timeOutUsed}.");

            Log.Log.Instance.AddEntry(Log.LogType.LogWarning, $"Mutex {Name} timeout: {timeOutUsed}.");
            return true; // retry
        }

        // ************************************************************************
        public void Dispose()
        {
            if (Mutex != null)
            {
                Mutex.ReleaseMutex();
                Mutex.Close();
            }
        }

        // ************************************************************************

    }
}

Awaiter

using System;

namespace HQ.Util.General.Threading
{
    public class MutexGlobalAwaiter : IDisposable
    {
        MutexGlobal _mutexGlobal = null;

        public bool HasTimedOut { get; set; } = false;

        internal MutexGlobalAwaiter(MutexGlobal mutexEx, int timeOut)
        {
            _mutexGlobal = mutexEx;

            do
            {
                HasTimedOut = !_mutexGlobal.Mutex.WaitOne(timeOut, false);
                if (! HasTimedOut) // Signal received
                {
                    return;
                }
            } while (_mutexGlobal.FuncTimeOutRetry(timeOut));
        }

        #region IDisposable Support
        private bool disposedValue = false; // To detect redundant calls

        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                if (disposing)
                {
                    _mutexGlobal.Mutex.ReleaseMutex();
                }

                // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
                // TODO: set large fields to null.

                disposedValue = true;
            }
        }
        // TODO: override a finalizer only if Dispose(bool disposing) above has code to free unmanaged resources.
        // ~MutexExAwaiter()
        // {
        //   // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
        //   Dispose(false);
        // }

        // This code added to correctly implement the disposable pattern.
        public void Dispose()
        {
            // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
            Dispose(true);
            // TODO: uncomment the following line if the finalizer is overridden above.
            // GC.SuppressFinalize(this);
        }
        #endregion
    }
}

fetch in git doesn't get all branches

I had to go into my GitExtensions Remote Repositories as nothing here seemed to be working. There I saw that 2 branches had no remote repository configured. after adjusting it looks as followsenter image description here

Notice branch noExternal3 still shows as not having a remote repository. Not sure what combo of bash commands would have found or adjusted that.

What does "<>" mean in Oracle

It means 'not equal to'. So you're filtering out records where ordid is 605. Overall you're looking for any records which have the same prodid and qty values as those assigned to ordid 605, but which are for a different order.

Differences between unique_ptr and shared_ptr

unique_ptr
is a smart pointer which owns an object exclusively.

shared_ptr
is a smart pointer for shared ownership. It is both copyable and movable. Multiple smart pointer instances can own the same resource. As soon as the last smart pointer owning the resource goes out of scope, the resource will be freed.

How do I run a simple bit of code in a new thread?

another option, that uses delegates and the Thread Pool...

assuming 'GetEnergyUsage' is a method that takes a DateTime and another DateTime as input arguments, and returns an Int...

// following declaration of delegate ,,,
public delegate long GetEnergyUsageDelegate(DateTime lastRunTime, 
                                            DateTime procDateTime);

// following inside of some client method 
GetEnergyUsageDelegate nrgDel = GetEnergyUsage;                     
IAsyncResult aR = nrgDel.BeginInvoke(lastRunTime, procDT, null, null);
while (!aR.IsCompleted) Thread.Sleep(500);
int usageCnt = nrgDel.EndInvoke(aR);

Difference between add(), replace(), and addToBackStack()

Here is a picture that shows the difference between add() and replace()

enter image description here

So add() method keeps on adding fragments on top of the previous fragment in FragmentContainer.

While replace() methods clears all the previous Fragment from Containers and then add it in FragmentContainer.

What is addToBackStack

addtoBackStack method can be used with add() and replace methods. It serves a different purpose in Fragment API.

What is the purpose?

Fragment API unlike Activity API does not come with Back Button navigation by default. If you want to go back to the previous Fragment then the we use addToBackStack() method in Fragment. Let's understand both

Case 1:

getSupportFragmentManager()
            .beginTransaction()
            .add(R.id.fragmentContainer, fragment, "TAG")
            .addToBackStack("TAG")
            .commit();

enter image description here

Case 2:

getSupportFragmentManager()
            .beginTransaction()
            .add(R.id.fragmentContainer, fragment, "TAG")
            .commit();

enter image description here

Change text from "Submit" on input tag

<input name="submitBnt" type="submit" value="like"/>

name is useful when using $_POST in php and also in javascript as document.getElementByName('submitBnt'). Also you can use name as a CS selector like input[name="submitBnt"]; Hope this helps

How can I exclude a directory from Visual Studio Code "Explore" tab?

In version 1.28 of Visual Studio Code "files.exclude" must be placed within a settings node.

Resulting in a workspace file that looks like:

{
    "settings": {
        "files.exclude": {
            "**/node_modules": true
        }
    }
}

Set a persistent environment variable from cmd.exe

Use the SETX command (note the 'x' suffix) to set variables that persist after the cmd window has been closed.

For example, to set an env var "foo" with value of "bar":

setx foo bar

Though it's worth reading the 'notes' that are displayed if you print the usage (setx /?), in particular:

2) On a local system, variables created or modified by this tool will be available in future command windows but not in the current CMD.exe command window.

3) On a remote system, variables created or modified by this tool will be available at the next logon session.

In PowerShell, the [Environment]::SetEnvironmentVariable command.

Importing project into Netbeans

Try copying the src and web folder in different folder location and create New project with existing sources in Netbeans. This should work. Or remove the nbproject folder as well before importing.

How to negate a method reference predicate

You can accomplish this as long emptyStrings = s.filter(s->!s.isEmpty()).count();

The transaction manager has disabled its support for remote/network transactions

In my scenario, the exception was being thrown because I was trying to create a new connection instance within a TransactionScope on an already existing connection:

Example:

void someFunction()
{
    using (var db = new DBContext(GetConnectionString()))
    {
        using (var transaction = new TransactionScope(TransactionScopeOption.Required, new TransactionOptions { IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted }))
        {
            someOtherFunction(); // This function opens a new connection within this transaction, causing the exception.
        }
    }
}

void someOtherFunction()
{
    using (var db = new DBContext(GetConnectionString()))
    {
        db.Whatever // <- Exception.
    }
}

Where and why do I have to put the "template" and "typename" keywords?

This answer is meant to be a rather short and sweet one to answer (part of) the titled question. If you want an answer with more detail that explains why you have to put them there, please go here.


The general rule for putting the typename keyword is mostly when you're using a template parameter and you want to access a nested typedef or using-alias, for example:

template<typename T>
struct test {
    using type = T; // no typename required
    using underlying_type = typename T::type // typename required
};

Note that this also applies for meta functions or things that take generic template parameters too. However, if the template parameter provided is an explicit type then you don't have to specify typename, for example:

template<typename T>
struct test {
    // typename required
    using type = typename std::conditional<true, const T&, T&&>::type;
    // no typename required
    using integer = std::conditional<true, int, float>::type;
};

The general rules for adding the template qualifier are mostly similar except they typically involve templated member functions (static or otherwise) of a struct/class that is itself templated, for example:

Given this struct and function:

template<typename T>
struct test {
    template<typename U>
    void get() const {
        std::cout << "get\n";
    }
};

template<typename T>
void func(const test<T>& t) {
    t.get<int>(); // error
}

Attempting to access t.get<int>() from inside the function will result in an error:

main.cpp:13:11: error: expected primary-expression before 'int'
     t.get<int>();
           ^
main.cpp:13:11: error: expected ';' before 'int'

Thus in this context you would need the template keyword beforehand and call it like so:

t.template get<int>()

That way the compiler will parse this properly rather than t.get < int.

How to get the current date without the time?

DateTime.Now.ToString("dd/MM/yyyy");

How should I call 3 functions in order to execute them one after the other?

You could also use promises in this way:

    some_3secs_function(this.some_value).then(function(){
       some_5secs_function(this.some_other_value).then(function(){
          some_8secs_function(this.some_other_other_value);
       });
    });

You would have to make some_value global in order to access it from inside the .then

Alternatively, from the outer function you could return the value the inner function would use, like so:

    one(some_value).then(function(return_of_one){
       two(return_of_one).then(function(return_of_two){
          three(return_of_two);
       });
    });

ES6 Update

Since async/await is widely available now, this is the way to accomplish the same:

async function run(){    
    await $('#art1').animate({'width':'1000px'},1000,'linear').promise()
    await $('#art2').animate({'width':'1000px'},1000,'linear').promise()
    await $('#art3').animate({'width':'1000px'},1000,'linear').promise()
}

Which is basically "promisifying" your functions (if they're not already asynchronous), and then awaiting them

How can I check which version of Angular I'm using?

Edit: When this answer was written, there was only AngularJS 1.x. Look in the answers below for Angular versions >= 2.

AngularJS does not have a command line tool.

You can get the version number from the JavaScript file itself.

Header of the current angular.js:

/**
 * @license AngularJS v1.0.6
 * (c) 2010-2012 Google, Inc. http://angularjs.org
 * License: MIT
 */

Array of an unknown length in C#

In a nutshell, please use Collections and Generics.

It's a must for any C# developer, it's worth spending time to learn :)

What does AND 0xFF do?

if byte1 is an 8-bit integer type then it's pointless - if it is more than 8 bits it will essentially give you the last 8 bits of the value:

    0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
 &  0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
    -------------------------------
    0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1

How to check if a file is a valid image file?

In addition to what Brian is suggesting you could use PIL's verify method to check if the file is broken.

im.verify()

Attempts to determine if the file is broken, without actually decoding the image data. If this method finds any problems, it raises suitable exceptions. This method only works on a newly opened image; if the image has already been loaded, the result is undefined. Also, if you need to load the image after using this method, you must reopen the image file. Attributes

How do I generate sourcemaps when using babel and webpack?

On Webpack 2 I tried all 12 devtool options. The following options link to the original file in the console and preserve line numbers. See the note below re: lines only.

https://webpack.js.org/configuration/devtool

devtool best dev options

                                build   rebuild      quality                       look
eval-source-map                 slow    pretty fast  original source               worst
inline-source-map               slow    slow         original source               medium
cheap-module-eval-source-map    medium  fast         original source (lines only)  worst
inline-cheap-module-source-map  medium  pretty slow  original source (lines only)  best

lines only

Source Maps are simplified to a single mapping per line. This usually means a single mapping per statement (assuming you author is this way). This prevents you from debugging execution on statement level and from settings breakpoints on columns of a line. Combining with minimizing is not possible as minimizers usually only emit a single line.

REVISITING THIS

On a large project I find ... eval-source-map rebuild time is ~3.5s ... inline-source-map rebuild time is ~7s

is the + operator less performant than StringBuffer.append()

As far I know, every concatenation implies a memory reallocation. So the problem is not the operator used to do it, the solution is to reduce the number of concatenations. For example do the concatenations outside of the iteration structures when you can.

How to convert 'binary string' to normal string in Python3?

Please, see oficial encode() and decode() documentation from codecs library. utf-8 is the default encoding for the functions, but there are severals standard encodings in Python 3, like latin_1 or utf_32.

SQL keys, MUL vs PRI vs UNI

UNI: For UNIQUE:

  • It is a set of one or more columns of a table to uniquely identify the record.
  • A table can have multiple UNIQUE key.
  • It is quite like primary key to allow unique values but can accept one null value which primary key does not.

PRI: For PRIMARY:

  • It is also a set of one or more columns of a table to uniquely identify the record.
  • A table can have only one PRIMARY key.
  • It is quite like UNIQUE key to allow unique values but does not allow any null value.

MUL: For MULTIPLE:

  • It is also a set of one or more columns of a table which does not identify the record uniquely.
  • A table can have more than one MULTIPLE key.
  • It can be created in table on index or foreign key adding, it does not allow null value.
  • It allows duplicate entries in column.
  • If we do not specify MUL column type then it is quite like a normal column but can allow null entries too hence; to restrict such entries we need to specify it.
  • If we add indexes on column or add foreign key then automatically MUL key type added.

AWS Lambda import module error in python

Sharing my solution for the same issue, just in case it helps anyone.

Issue: I got error: "[ERROR] Runtime.ImportModuleError: Unable to import module 'lambda_function': No module named 'StringIO'" while executing aws-big-data-blog code[1] provided in AWS article[2].

Solution: Changed Runtime from Python 3.7 to Python 2.7

[1] — https://github.com/bsnively/aws-big-data-blog/blob/master/aws-blog-vpcflowlogs-athena-quicksight/CloudwatchLogsToFirehose/lambdacode.py [2] — https://aws.amazon.com/blogs/big-data/analyzing-vpc-flow-logs-with-amazon-kinesis-firehose-amazon-athena-and-amazon-quicksight/

Pandas split DataFrame by column value

Using groupby you could split into two dataframes like

In [1047]: df1, df2 = [x for _, x in df.groupby(df['Sales'] < 30)]

In [1048]: df1
Out[1048]:
   A  Sales
2  7     30
3  6     40
4  1     50

In [1049]: df2
Out[1049]:
   A  Sales
0  3     10
1  4     20

Changing text color of menu item in navigation drawer

I used below code to change Navigation drawer text color in my app.

NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setItemTextColor(ColorStateList.valueOf(Color.WHITE));

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

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

Copying the content from the above link for quick reference:

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

How do I minimize the command prompt from my bat file

If you want to start the batch for Win-Run / autostart, I found I nice solution here https://www.computerhope.com/issues/ch000932.htm & https://superuser.com/questions/364799/how-to-run-the-command-prompt-minimized

cmd.exe /c start /min myfile.bat ^& exit
  • the cmd.exe is needed as start is no windows command that can be executed outside a batch
  • /c = exit after the start is finished
  • the ^& exit part ensures that the window closes even if the batch does not end with exit

However, the initial cmd is still not minimized.

Simulating group_concat MySQL function in Microsoft SQL Server 2005?

Possibly too late to be of benefit now, but is this not the easiest way to do things?

SELECT     empName, projIDs = replace
                          ((SELECT Surname AS [data()]
                              FROM project_members
                              WHERE  empName = a.empName
                              ORDER BY empName FOR xml path('')), ' ', REQUIRED SEPERATOR)
FROM         project_members a
WHERE     empName IS NOT NULL
GROUP BY empName

Passing headers with axios POST request

Shubham answer didn't work for me.

When you are using axios library and to pass custom headers, you need to construct headers as an object with key name "headers". The headers key should contain an object, here it is Content-Type and Authorization.

Below example is working fine.

    var headers = {
        'Content-Type': 'application/json',
        'Authorization': 'JWT fefege...' 
    }
    axios.post(Helper.getUserAPI(), data, {"headers" : headers})

        .then((response) => {
            dispatch({type: FOUND_USER, data: response.data[0]})
        })
        .catch((error) => {
            dispatch({type: ERROR_FINDING_USER})
        })

Unit tests vs Functional tests

Unit tests tell a developer that the code is doing things right; functional tests tell a developer that the code is doing the right things.

You can read more at Unit Testing versus Functional Testing


A well explained real-life analogy of unit testing and functional testing can be described as follows,

Many times the development of a system is likened to the building of a house. While this analogy isn't quite correct, we can extend it for the purposes of understanding the difference between unit and functional tests.

Unit testing is analogous to a building inspector visiting a house's construction site. He is focused on the various internal systems of the house, the foundation, framing, electrical, plumbing, and so on. He ensures (tests) that the parts of the house will work correctly and safely, that is, meet the building code.

Functional tests in this scenario are analogous to the homeowner visiting this same construction site. He assumes that the internal systems will behave appropriately, that the building inspector is performing his task. The homeowner is focused on what it will be like to live in this house. He is concerned with how the house looks, are the various rooms a comfortable size, does the house fit the family's needs, are the windows in a good spot to catch the morning sun.

The homeowner is performing functional tests on the house. He has the user's perspective.

The building inspector is performing unit tests on the house. He has the builder's perspective.


As a summary,

Unit Tests are written from a programmers perspective. They are made to ensure that a particular method (or a unit) of a class performs a set of specific tasks.

Functional Tests are written from the user's perspective. They ensure that the system is functioning as users are expecting it to.

How to add conditional attribute in Angular 2?

I wanted to have tooltip only for a particular field as added below in code but you want to have tooltip on multiplent you can have an array valdidate using:

Multiple Elements haveing custom data-tooltip attribute:

1: ['key1ToHaveTooltip', `key2ToHaveTooltip'].includes(key)

2: ['key1ToHaveTooltip', 'key2ToHaveTooltip'].indexOf(key) > -1

to have tooltip attribute on more than 1 element.

   <div *ngFor="let key of Keys"
             [attr.data-tooltip]="key === 'IwantOnlyThisKeyToHaveTooltipAttribute' 
                                           ? 'Hey! I am a tooltip on key matched'
                                           : null">
   </div>

Delete all lines beginning with a # from a file

I'm a little surprised nobody has suggested the most obvious solution:

grep -v '^#' filename

This solves the problem as stated.

But note that a common convention is for everything from a # to the end of a line to be treated as a comment:

sed 's/#.*$//' filename

though that treats, for example, a # character within a string literal as the beginning of a comment (which may or may not be relevant for your case) (and it leaves empty lines).

A line starting with arbitrary whitespace followed by # might also be treated as a comment:

grep -v '^ *#' filename

if whitespace is only spaces, or

grep -v '^[  ]#' filename

where the two spaces are actually a space followed by a literal tab character (type "control-v tab").

For all these commands, omit the filename argument to read from standard input (e.g., as part of a pipe).

SQL select * from column where year = 2010

T-SQL and others;

select * from t where year(Columnx) = 2010

Laravel-5 'LIKE' equivalent (Eloquent)

$data = DB::table('borrowers')
        ->join('loans', 'borrowers.id', '=', 'loans.borrower_id')
        ->select('borrowers.*', 'loans.*')   
        ->where('loan_officers', 'like', '%' . $officerId . '%')
        ->where('loans.maturity_date', '<', date("Y-m-d"))
        ->get();

Create Directory When Writing To File In Node.js

My advise is: try not to rely on dependencies when you can easily do it with few lines of codes

Here's what you're trying to achieve in 14 lines of code:

fs.isDir = function(dpath) {
    try {
        return fs.lstatSync(dpath).isDirectory();
    } catch(e) {
        return false;
    }
};
fs.mkdirp = function(dirname) {
    dirname = path.normalize(dirname).split(path.sep);
    dirname.forEach((sdir,index)=>{
        var pathInQuestion = dirname.slice(0,index+1).join(path.sep);
        if((!fs.isDir(pathInQuestion)) && pathInQuestion) fs.mkdirSync(pathInQuestion);
    });
};

How to build minified and uncompressed bundle with webpack?

You can run webpack twice with different arguments:

$ webpack --minimize

then check command line arguments in webpack.config.js:

var path = require('path'),
  webpack = require('webpack'),
  minimize = process.argv.indexOf('--minimize') !== -1,
  plugins = [];

if (minimize) {
  plugins.push(new webpack.optimize.UglifyJsPlugin());
}

...

example webpack.config.js

How can you make a custom keyboard in Android?

Here is a sample project for a soft keyboard.

https://developer.android.com/guide/topics/text/creating-input-method.html

Your's should be in the same lines with a different layout.

Edit: If you need the keyboard only in your application, its very simple! Create a linear layout with vertical orientation, and create 3 linear layouts inside it with horizontal orientation. Then place the buttons of each row in each of those horizontal linear layouts, and assign the weight property to the buttons. Use android:layout_weight=1 for all of them, so they get equally spaced.

This will solve. If you didn't get what was expected, please post the code here, and we are here to help you!

How to thoroughly purge and reinstall postgresql on ubuntu?

I was facing same problem in my ubuntu 16.04

but i fixed that problem and it's very simple just follow these step and you will be able to install postgresql 10 in your system :

Add this to your sources.list:

sudo vim /etc/apt/sources.list

deb http://ftp.de.debian.org/debian/ wheezy main non-free contrib

deb-src http://ftp.de.debian.org/debian/ wheezy main non-free contrib

after that add these link to your pgdg.list file if it's not there you have to create && add link && save it.

sudo vim /etc/apt/sources.list.d/pgdg.list

deb http://apt.postgresql.org/pub/repos/apt/ xenial-pgdg main

deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main

then update your system

sudo apt-get update

sudo apt-get upgrade

and install that unmet dependencies :

apt-get install ssl-cert

that's it. now Install postgresql using these command

sudo apt-get install postgresql-10

Using jq to parse and display multiple fields in a json serially

While both of the above answers work well if key,value are strings, I had a situation to append a string and integer (jq errors using the above expressions)

Requirement: To construct a url out below json

pradeep@seleniumframework>curl http://192.168.99.103:8500/v1/catalog/service/apache-443 | jq .[0]
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   251  100   251    0     0   155k      0 --:--:-- --:--:-- --:--:--  245k
{
  "Node": "myconsul",
  "Address": "192.168.99.103",
  "ServiceID": "4ce41e90ede4:compassionate_wozniak:443",
  "ServiceName": "apache-443",
  "ServiceTags": [],
  "ServiceAddress": "",
  "ServicePort": 1443,
  "ServiceEnableTagOverride": false,
  "CreateIndex": 45,
  "ModifyIndex": 45
}

Solution:

curl http://192.168.99.103:8500/v1/catalog/service/apache-443 |
jq '.[0] | "http://" + .Address + ":" + "\(.ServicePort)"'

Sublime Text 3, convert spaces to tabs

In my case, this line solved the problem:

"translate_tabs_to_spaces": false

Is key-value pair available in Typescript?

Another simple way is to use a tuple:

// Declare a tuple type
let x: [string, number];
// Initialize it
x = ["hello", 10];
// Access elements
console.log("First: " + x["0"] + " Second: " + x["1"]);

Output:

First: hello Second: 10

What exactly does the .join() method do?

"".join may be used to copy the string in a list to a variable

>>> myList = list("Hello World")
>>> myString = "".join(myList)
>>> print(myList)
['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
>>> print(myString)
Hello World

How do I pass JavaScript values to Scriptlet in JSP?

Its not possible as you are expecting. But you can do something like this. Pass the your java script value to the servlet/controller, do your processing and then pass this value to the jsp page by putting it into some object's as your requirement. Then you can use this value as you want.

In Subversion can I be a user other than my login name?

Using Subversion with either the Apache module or svnserve. I've been able to perform operations as multiple users using --username.

Each time you invoke a Subversion command as a 'new' user, your $HOME/.subversion/auth/<authentication-method>/ directory will have a new entry cached for that user (assuming you are able to authenticate with the correct password or authentication method for the server you are contacting as that particular user).

How to remove certain characters from a string in C++?

Yes, you can use the isdigit() function to check for a digits :)

Here you go:

#include <iostream>
#include <cctype>
#include <string.h>

using namespace std;

int main(){

  char *str = "(555) 555-5555";
  int len = strlen(str);

  for (int i=0; i<len; i++){
      if (isdigit(*(str+i))){
        cout << *(str+i);
      }
  }

  cout << endl;


return 0;   
}

Hope it helps :)

How to return value from function which has Observable subscription inside?

EDIT: updated code in order to reflect changes made to the way pipes work in more recent versions of RXJS. All operators (take in my example) are now wrapped into the pipe() operator.

I realize that this Question was quite a while ago and you surely have a proper solution by now, but for anyone looking for this I would suggest solving it with a Promise to keep the async pattern.

A more verbose version would be creating a new Promise:

function getValueFromObservable() {
    return new Promise(resolve=>{
        this.store.pipe(
           take(1) //useful if you need the data once and don't want to manually cancel the subscription again
         )
         .subscribe(
            (data:any) => {
                console.log(data);
                resolve(data);
         })
    })
}

On the receiving end you will then have "wait" for the promise to resolve with something like this:

getValueFromObservable()
   .then((data:any)=>{
   //... continue with anything depending on "data" after the Promise has resolved
})

A slimmer solution would be using RxJS' .toPromise() instead:

function getValueFromObservable() {
    return this.store.pipe(take(1))
       .toPromise()   
}

The receiving side stays the same as above of course.

How to generate different random numbers in a loop in C++?

Stop seeding the generator every time. Pull the srand call out of the loop

How to plot an array in python?

if you give a 2D array to the plot function of matplotlib it will assume the columns to be lines:

If x and/or y is 2-dimensional, then the corresponding columns will be plotted.

In your case your shape is not accepted (100, 1, 1, 8000). As so you can using numpy squeeze to solve the problem quickly:

np.squeez doc: Remove single-dimensional entries from the shape of an array.

import numpy as np
import matplotlib.pyplot as plt

data = np.random.randint(3, 7, (10, 1, 1, 80))
newdata = np.squeeze(data) # Shape is now: (10, 80)
plt.plot(newdata) # plotting by columns
plt.show()

But notice that 100 sets of 80 000 points is a lot of data for matplotlib. I would recommend that you look for an alternative. The result of the code example (run in Jupyter) is:

Jupyter matplotlib plot

Using setTimeout to delay timing of jQuery actions

.html() only takes a string OR a function as an argument, not both. Try this:

 $("#showDiv").click(function () {
     $('#theDiv').show(1000, function () {
         setTimeout(function () {
             $('#theDiv').html(function () {
                 setTimeout(function () {
                     $('#theDiv').html('Here is some replacement text');
                 }, 0);
                 setTimeout(function () {
                     $('#theDiv').html('More replacement text goes here');
                 }, 2500);
             });
         }, 2500);
     });
 }); //click function ends

jsFiddle example

How do I add a library project to Android Studio?

Android Studio 3.0

Just add the library name to the dependencies block of your app's build.gradle file.

dependencies {
    // ...
    implementation 'com.example:some-library:1.0.0'
}

Note that you should use implementation rather than compile now. This is new with Android Studio 3.0. See this Q&A for an explanation of the difference.

Get the new record primary key ID from MySQL insert query?

If you need the value before insert a row:

CREATE FUNCTION `getAutoincrementalNextVal`(`TableName` VARCHAR(50))
    RETURNS BIGINT
    LANGUAGE SQL
    NOT DETERMINISTIC
    CONTAINS SQL
    SQL SECURITY DEFINER
    COMMENT ''
BEGIN

    DECLARE Value BIGINT;

    SELECT
        AUTO_INCREMENT INTO Value
    FROM
        information_schema.tables
    WHERE
        table_name = TableName AND
        table_schema = DATABASE();

    RETURN Value;

END

You can use this in a insert:

INSERT INTO
    document (Code, Title, Body)
VALUES (                
    sha1( concat (convert ( now() , char), ' ',   getAutoincrementalNextval ('document') ) ),
    'Title',
    'Body'
);

How many socket connections can a web server handle?

in case of the IPv4 protocol, the server with one IP address that listens on one port only can handle 2^32 IP addresses x 2^16 ports so 2^48 unique sockets. If you speak about a server as a physical machine, and you are able to utilize all 2^16 ports, then there could be maximum of 2^48 x 2^16 = 2^64 unique TCP/IP sockets for one IP address. Please note that some ports are reserved for the OS, so this number will be lower. To sum up:

1 IP and 1 port --> 2^48 sockets

1 IP and all ports --> 2^64 sockets

all unique IPv4 sockets in the universe --> 2^96 sockets

POST data with request module on Node.JS

var request = require('request');
request.post('http://localhost/test2.php', 
    {form:{ mes: "heydude" }}, 
    function(error, response, body){
        console.log(body);
});

How do I keep track of pip-installed packages in an Anaconda (Conda) environment?

This is why I wrote Picky: http://picky.readthedocs.io/

It's a python package that tracks packages installed with either pip or conda in either virtualenvs and conda envs.

Using DISTINCT and COUNT together in a MySQL Query

What the hell of all this work anthers

it's too simple

if you want a list of how much productId in each keyword here it's the code

SELECT count(productId),  keyword  FROM `Table_name` GROUP BY keyword; 

How to convert DATE to UNIX TIMESTAMP in shell script on MacOS

date -j -f "%Y-%m-%d %H:%M:%S" "2020-04-07 00:00:00" "+%s"

It will print the dynamic seconds when without %H:%M:%S and 00:00:00.

Can I redirect the stdout in python into some sort of string buffer?

There is contextlib.redirect_stdout() function in Python 3.4:

import io
from contextlib import redirect_stdout

with io.StringIO() as buf, redirect_stdout(buf):
    print('redirected')
    output = buf.getvalue()

Here's code example that shows how to implement it on older Python versions.

Display current time in 12 hour format with AM/PM

import java.text.SimpleDateFormat;
import java.text.DateFormat;
import java.util.Date;

public class Main {
   public static void main(String [] args){
       try {
            DateFormat parseFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm a");
            String sDate = "22-01-2019 13:35 PM";
            Date date = parseFormat.parse(sDate);
            SimpleDateFormat displayFormat = new SimpleDateFormat("dd-MM-yyyy hh:mm a");
            sDate = displayFormat.format(date);
            System.out.println("The required format : " + sDate);
        } catch (Exception e) {}
   }
}

How to view DLL functions?

For native code it's probably best to use Dependency Walker. It also possible to use dumpbin command line utility that comes with Visual Studio.

Python 'list indices must be integers, not tuple"

To create list of lists, you need to separate them with commas, like this

coin_args = [
    ["pennies", '2.5', '50.0', '.01'],
    ["nickles", '5.0', '40.0', '.05'],
    ["dimes", '2.268', '50.0', '.1'],
    ["quarters", '5.67', '40.0', '.25']
]

"Bitmap too large to be uploaded into a texture"

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);
    ///*
    if (requestCode == PICK_FROM_FILE && resultCode == RESULT_OK && null != data){



        uri = data.getData();

        String[] prjection ={MediaStore.Images.Media.DATA};

        Cursor cursor = getContentResolver().query(uri,prjection,null,null,null);

        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(prjection[0]);

        ImagePath = cursor.getString(columnIndex);

        cursor.close();

        FixBitmap = BitmapFactory.decodeFile(ImagePath);

        ShowSelectedImage = (ImageView)findViewById(R.id.imageView);

      //  FixBitmap = new BitmapDrawable(ImagePath);
        int nh = (int) ( FixBitmap.getHeight() * (512.0 / FixBitmap.getWidth()) );
        FixBitmap = Bitmap.createScaledBitmap(FixBitmap, 512, nh, true);

       // ShowSelectedImage.setImageBitmap(BitmapFactory.decodeFile(ImagePath));

        ShowSelectedImage.setImageBitmap(FixBitmap);

    }
}

This code is work

npm ERR! Error: EPERM: operation not permitted, rename

This is a typical error caused by Antivirus. There is a workaround for cases like mine, where I can't disable A/V (Company Policy).

You have to change the polyfills.js inside Npm package:

[NODE_HOME]/node_modules/npm/node_modules/graceful_fs/polyfills.js

Look for this statement:

if (process.platform === "win32") {

Inside of this statement, there is a timeout making a retry in case of error. The problem is that in some cases, after the timeout, the file is still locked by the A/V. The solution is rip out the timeout and let this statement in loop. The change with the previous code commented:

if (platform === "win32") {

fs.rename = (function (fs$rename) { return function (from, to, cb) {
  var start = Date.now()
  var backoff = 0;
  fs$rename(from, to, function CB (er) {
    if (er
        && (er.code === "EACCES" || er.code === "EPERM")
        /*&& Date.now() - start < 60000*/) {
            console.log("Retrying rename file: " + from + " <> " + to)
            fs$rename(from, to, CB);
      /*setTimeout(function() {
        fs.stat(to, function (stater, st) {
          if (stater && stater.code === "ENOENT")
            fs$rename(from, to, CB);
          else
            cb(er)
        })
      }, backoff)*/
      if (backoff < 100)
        backoff += 10;
      return;
    }
    if (cb) cb(er)
  })
}})(fs.rename)
}

Automating the InvokeRequired code pattern

Usage:

control.InvokeIfRequired(c => c.Visible = false);

return control.InvokeIfRequired(c => {
    c.Visible = value

    return c.Visible;
});

Code:

using System;
using System.ComponentModel;

namespace Extensions
{
    public static class SynchronizeInvokeExtensions
    {
        public static void InvokeIfRequired<T>(this T obj, Action<T> action)
            where T : ISynchronizeInvoke
        {
            if (obj.InvokeRequired)
            {
                obj.Invoke(action, new object[] { obj });
            }
            else
            {
                action(obj);
            }
        }

        public static TOut InvokeIfRequired<TIn, TOut>(this TIn obj, Func<TIn, TOut> func) 
            where TIn : ISynchronizeInvoke
        {
            return obj.InvokeRequired
                ? (TOut)obj.Invoke(func, new object[] { obj })
                : func(obj);
        }
    }
}

Get the index of the object inside an array, matching a condition

Try this code

var x = [{prop1:"abc",prop2:"qwe"},{prop1:"bnmb",prop2:"yutu"},{prop1:"zxvz",prop2:"qwrq"}]
let index = x.findIndex(x => x.prop1 === 'zxvz')

No Persistence provider for EntityManager named

Make sure that the persistence.xml file is in the directory: <webroot>/WEB-INF/classes/META-INF

Getting last day of the month in a given string date

With Java 8 DateTime / LocalDateTime :

String dateString = "01/13/2012";
DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("MM/dd/yyyy", Locale.US); 
LocalDate date = LocalDate.parse(dateString, dateFormat);       
ValueRange range = date.range(ChronoField.DAY_OF_MONTH);
Long max = range.getMaximum();
LocalDate newDate = date.withDayOfMonth(max.intValue());
System.out.println(newDate); 

OR

String dateString = "01/13/2012";
DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("MM/dd/yyyy", Locale.US); 
LocalDate date = LocalDate.parse(dateString, dateFormat);
LocalDate newDate = date.withDayOfMonth(date.getMonth().length(date.isLeapYear()));
System.out.println(newDate);

Output:

2012-01-31

LocalDateTime should be used instead of LocalDate if you have time information in your date string . I.E. 2015/07/22 16:49

Byte[] to InputStream or OutputStream

output = new ByteArrayOutputStream();
...
input = new ByteArrayInputStream( output.toByteArray() )

Python Script Uploading files via FTP

Use ftplib, you can write it like this:

import ftplib
session = ftplib.FTP('server.address.com','USERNAME','PASSWORD')
file = open('kitten.jpg','rb')                  # file to send
session.storbinary('STOR kitten.jpg', file)     # send the file
file.close()                                    # close file and FTP
session.quit()

Use ftplib.FTP_TLS instead if you FTP host requires TLS.


To retrieve it, you can use urllib.retrieve:

import urllib 

urllib.urlretrieve('ftp://server/path/to/file', 'file')

EDIT:

To find out the current directory, use FTP.pwd():

FTP.pwd(): Return the pathname of the current directory on the server.

To change the directory, use FTP.cwd(pathname):

FTP.cwd(pathname): Set the current directory on the server.

Checking version of angular-cli that's installed?

Go to your folder path in cmd where your angular is installed and type ng --version it will show your angular version. Thanks.

SQL Server - transactions roll back on error?

If one of the inserts fail, or any part of the command fails, does SQL server roll back the transaction?

No, it does not.

If it does not rollback, do I have to send a second command to roll it back?

Sure, you should issue ROLLBACK instead of COMMIT.

If you want to decide whether to commit or rollback the transaction, you should remove the COMMIT sentence out of the statement, check the results of the inserts and then issue either COMMIT or ROLLBACK depending on the results of the check.

Regex in JavaScript for validating decimal numbers

Does this work?

[0-9]{2}.[0-9]{2}

Why use ICollection and not IEnumerable or List<T> on many-many/one-many relationships?

What I have done in the past is declare my inner class collections using IList<Class>, ICollection<Class>or IEnumerable<Class> (if static list) depending on whether or not I will have to do any number of the following in a method in my repository: enumerate, sort/order or modify. When I just need to enumerate (and maybe sort) over objects then I create a temp List<Class>to work with the collection within an IEnumerable method. I think this practice would only be effective if the collection is relatively small, but it may be good practice in general, idk. Please correct me if there is evidence as to why this would not good practice.

Difference between DataFrame, Dataset, and RDD in Spark

A Dataframe is an RDD of Row objects, each representing a record. A Dataframe also knows the schema (i.e., data fields) of its rows. While Dataframes look like regular RDDs, internally they store data in a more efficient manner, taking advantage of their schema. In addition, they provide new operations not available on RDDs, such as the ability to run SQL queries. Dataframes can be created from external data sources, from the results of queries, or from regular RDDs.

Reference: Zaharia M., et al. Learning Spark (O'Reilly, 2015)

Is bool a native C type?

/* Many years ago, when the earth was still cooling, we used this: */

typedef enum
{
    false = ( 1 == 0 ),
    true = ( ! false )
} bool;

/* It has always worked for me. */

Provisioning Profiles menu item missing from Xcode 5

You can add account in the preference -> Accounts setting.

It seems that you already configure xCode4, then I think you can select your certificates for compiling in project-> Building Setting directly since your certificates are already in your keychain.

Permission denied (publickey,keyboard-interactive)

You may want to double check the authorized_keys file permissions:

$ chmod 600 ~/.ssh/authorized_keys

Newer SSH server versions are very picky on this respect.

PHP CURL & HTTPS

Another option like Gavin Palmer answer is to use the .pem file but with a curl option

  1. download the last updated .pem file from https://curl.haxx.se/docs/caextract.html and save it somewhere on your server(outside the public folder)

  2. set the option in your code instead of the php.ini file.

In your code

curl_setopt($ch, CURLOPT_CAINFO, $_SERVER['DOCUMENT_ROOT'] .  "/../cacert-2017-09-20.pem");

NOTE: setting the cainfo in the php.ini like @Gavin Palmer did is better than setting it in your code like I did, because it will save a disk IO every time the function is called, I just make it like this in case you want to test the cainfo file on the fly instead of changing the php.ini while testing your function.

Angularjs if-then-else construction in expression

I am trying to check if a key exist in an array in angular way and landed here on this question. In my Angularjs 1.4 ternary operator worked like below

{{ CONDITION ? TRUE : FALSE }}

hence for the array key exist i did a simple JS check

Solution 1 : {{ array['key'] !== undefined ? array['key'] : 'n/a' }}

Solution 2 : {{ "key" in array ? array['key'] : 'n/a' }}

Token based authentication in Web API without any user interface

I think there is some confusion about the difference between MVC and Web Api. In short, for MVC you can use a login form and create a session using cookies. For Web Api there is no session. That's why you want to use the token.

You do not need a login form. The Token endpoint is all you need. Like Win described you'll send the credentials to the token endpoint where it is handled.

Here's some client side C# code to get a token:

    //using System;
    //using System.Collections.Generic;
    //using System.Net;
    //using System.Net.Http;
    //string token = GetToken("https://localhost:<port>/", userName, password);

    static string GetToken(string url, string userName, string password) {
        var pairs = new List<KeyValuePair<string, string>>
                    {
                        new KeyValuePair<string, string>( "grant_type", "password" ), 
                        new KeyValuePair<string, string>( "username", userName ), 
                        new KeyValuePair<string, string> ( "Password", password )
                    };
        var content = new FormUrlEncodedContent(pairs);
        ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
        using (var client = new HttpClient()) {
            var response = client.PostAsync(url + "Token", content).Result;
            return response.Content.ReadAsStringAsync().Result;
        }
    }

In order to use the token add it to the header of the request:

    //using System;
    //using System.Collections.Generic;
    //using System.Net;
    //using System.Net.Http;
    //var result = CallApi("https://localhost:<port>/something", token);

    static string CallApi(string url, string token) {
        ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
        using (var client = new HttpClient()) {
            if (!string.IsNullOrWhiteSpace(token)) {
                var t = JsonConvert.DeserializeObject<Token>(token);

                client.DefaultRequestHeaders.Clear();
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + t.access_token);
            }
            var response = client.GetAsync(url).Result;
            return response.Content.ReadAsStringAsync().Result;
        }
    }

Where Token is:

//using Newtonsoft.Json;

class Token
{
    public string access_token { get; set; }
    public string token_type { get; set; }
    public int expires_in { get; set; }
    public string userName { get; set; }
    [JsonProperty(".issued")]
    public string issued { get; set; }
    [JsonProperty(".expires")]
    public string expires { get; set; }
}

Now for the server side:

In Startup.Auth.cs

        var oAuthOptions = new OAuthAuthorizationServerOptions
        {
            TokenEndpointPath = new PathString("/Token"),
            Provider = new ApplicationOAuthProvider("self"),
            AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
            // https
            AllowInsecureHttp = false
        };
        // Enable the application to use bearer tokens to authenticate users
        app.UseOAuthBearerTokens(oAuthOptions);

And in ApplicationOAuthProvider.cs the code that actually grants or denies access:

//using Microsoft.AspNet.Identity.Owin;
//using Microsoft.Owin.Security;
//using Microsoft.Owin.Security.OAuth;
//using System;
//using System.Collections.Generic;
//using System.Security.Claims;
//using System.Threading.Tasks;

public class ApplicationOAuthProvider : OAuthAuthorizationServerProvider
{
    private readonly string _publicClientId;

    public ApplicationOAuthProvider(string publicClientId)
    {
        if (publicClientId == null)
            throw new ArgumentNullException("publicClientId");

        _publicClientId = publicClientId;
    }

    public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
    {
        var userManager = context.OwinContext.GetUserManager<ApplicationUserManager>();

        var user = await userManager.FindAsync(context.UserName, context.Password);
        if (user == null)
        {
            context.SetError("invalid_grant", "The user name or password is incorrect.");
            return;
        }

        ClaimsIdentity oAuthIdentity = await user.GenerateUserIdentityAsync(userManager);
        var propertyDictionary = new Dictionary<string, string> { { "userName", user.UserName } };
        var properties = new AuthenticationProperties(propertyDictionary);

        AuthenticationTicket ticket = new AuthenticationTicket(oAuthIdentity, properties);
        // Token is validated.
        context.Validated(ticket);
    }

    public override Task TokenEndpoint(OAuthTokenEndpointContext context)
    {
        foreach (KeyValuePair<string, string> property in context.Properties.Dictionary)
        {
            context.AdditionalResponseParameters.Add(property.Key, property.Value);
        }
        return Task.FromResult<object>(null);
    }

    public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
    {
        // Resource owner password credentials does not provide a client ID.
        if (context.ClientId == null)
            context.Validated();

        return Task.FromResult<object>(null);
    }

    public override Task ValidateClientRedirectUri(OAuthValidateClientRedirectUriContext context)
    {
        if (context.ClientId == _publicClientId)
        {
            var expectedRootUri = new Uri(context.Request.Uri, "/");

            if (expectedRootUri.AbsoluteUri == context.RedirectUri)
                context.Validated();
        }
        return Task.FromResult<object>(null);
    }

}

As you can see there is no controller involved in retrieving the token. In fact, you can remove all MVC references if you want a Web Api only. I have simplified the server side code to make it more readable. You can add code to upgrade the security.

Make sure you use SSL only. Implement the RequireHttpsAttribute to force this.

You can use the Authorize / AllowAnonymous attributes to secure your Web Api. Additionally you can add filters (like RequireHttpsAttribute) to make your Web Api more secure. I hope this helps.

What is the difference between procedural programming and functional programming?

To expand on Konrad's comment:

and the order of evaluation is not well-defined

Some functional languages have what is called Lazy Evaluation. Which means a function is not executed until the value is needed. Until that time the function itself is what is passed around.

Procedural languages are step 1 step 2 step 3... if in step 2 you say add 2 + 2, it does it right then. In lazy evaluation you would say add 2 + 2, but if the result is never used, it never does the addition.

Spring Boot not serving static content

In my case I have a spring boot application which is kind of mixing spring and jaxrs. So I have a java class which inherits from the class org.glassfish.jersey.server.ResourceConfig. I had to add this line to the constructor of that class so that the spring endpoints are still called: property(ServletProperties.FILTER_FORWARD_ON_404, true).

Which data type for latitude and longitude?

If you do not need all the functionality PostGIS offers, Postgres (nowadays) offers an extension module called earthdistance. It uses the point or cube data type depending on your accuracy needs for distance calculations.

You can now use the earth_box function to -for example- query for points within a certain distance of a location.

Copy Notepad++ text with formatting?

It is worth mentioning that 64-bit Notepad++ does not support Plugin Manager and NPPExport, so they won't be shown in Plugins menu. If you will try to add NPPExport plugin manually, most likely you'll see :

"NPPExport plugin is not supported with 64bit Notepad++"

Fortunately, there is NPP_Export plugin to download from here which works well with 64-bit Notepad++ (v7.2.2 in my case) and support for Plugin Manager is underway (check GitHub for updates).

Java: How To Call Non Static Method From Main Method?

Please find answer:

public class Customer {

    public static void main(String[] args) {
        Customer customer=new Customer();
        customer.business();
    }

    public void business(){
        System.out.println("Hi Harry");
    }
}

How to comment/uncomment in HTML code

/* (opener) */ (closer)

for example,

<html>
 /*<p>Commented P Tag </p>*/
<html>

Using Laravel Homestead: 'no input file specified'

I had the same issue while following the Laravel docs (https://laravel.com/docs/5.2/homestead)

My problem was very simple, I missed read this part in the docs:

Homestead.yaml file will be placed in the ~/.homestead hidden directory:

So I was updating the wrong Homestead.yaml file, since the file was moved when I ran the bash init.sh command.

I only realised this after a lot of searching, so hope this will help someone.

Eclipse returns error message "Java was started but returned exit code = 1"

The error message points to a problem with your Java version. Do you have a JDK installed?

Try adding the following (noting the new line):

/!\ make sure, that the -vm option occurs before the -vmargs command. Everything after -vmargs is passed directly to the JVM.

-vm 
c:/wherever/java/jdk1.6.0_21/jre/bin/server/jvm.dll
-vmargs... 

...to your eclipse.ini file, pointing to the JDK you want to use, and check that the required Java version is at least as new as your JDK. This is the path for a Windows system. More on paths can be found here (scroll down).

If you don't know where the eclipse.ini file is: regularly it is in the folder of your eclipse.exe.

Edit2: @KadoLakatt: the reason why installing the latest Java Version worked for you is because Eclipse checks the standard path for a JVM if it doesn't find a -vm entry (see here). However I'd not recommend that, since you might be wrong guessing the JVM used. If you update Java (automatically?) you might run into problems in your Eclipse wondering what you might have changed. Better set it to a specific folder in your eclipse.ini to be certain.

RecyclerView expand/collapse items

After using the recommended way of implementing expandable/collapsible items residing in a RecyclerView on RecyclerView expand/collapse items answered by HeisenBerg, I've seen some noticeable artifacts whenever the RecyclerView is refreshed by invoking TransitionManager.beginDelayedTransition(ViewGroup) and subsequently notifyDatasetChanged().

His original answer:

final boolean isExpanded = position==mExpandedPosition;
holder.details.setVisibility(isExpanded?View.VISIBLE:View.GONE);
holder.itemView.setActivated(isExpanded);
holder.itemView.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        mExpandedPosition = isExpanded ? -1 : position;
        TransitionManager.beginDelayedTransition(recyclerView);
        notifyDataSetChanged();
    }
});

Modified:

final boolean isExpanded = position == mExpandedPosition;
holder.details.setVisibility(isExpanded ? View.VISIBLE : View.GONE);
holder.view.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (mExpandedHolder != null) {
            mExpandedHolder.details.setVisibility(View.GONE);
            notifyItemChanged(mExpandedPosition);
        }
        mExpandedPosition = isExpanded ? -1 : holder.getAdapterPosition();
        mExpandedHolder = isExpanded ? null : holder;
        notifyItemChanged(holder.getAdapterPosition());
    }
}
  • details is view that you want to show/hide during item expand/collapse
  • mExpandedPosition is an int that keeps track of expanded item
  • mExpandedHolder is a ViewHolder used during item collapse

Notice that the method TransitionManager.beginDelayedTransition(ViewGroup) and notifyDataSetChanged() are replaced by notifyItemChanged(int) to target specific item and some little tweaks.

After the modification, the previous unwanted effects should be gone. However, this may not be the perfect solution. It only did what I wanted, eliminating the eyesores.

::EDIT::

For clarification, both mExpandedPosition and mExpandedHolder are globals.

Detect whether current Windows version is 32 bit or 64 bit

In C#:

public bool Is64bit() {
    return Marshal.SizeOf(typeof(IntPtr)) == 8;
}

In VB.NET:

Public Function Is64bit() As Boolean
   If Marshal.SizeOf(GetType(IntPtr)) = 8 Then Return True
   Return False
End Function

How to use Checkbox inside Select Option

I started from @vitfo answer but I want to have <option> inside <select> instead of checkbox inputs so i put together all the answers to make this, there is my code, I hope it will help someone.

_x000D_
_x000D_
$(".multiple_select").mousedown(function(e) {_x000D_
    if (e.target.tagName == "OPTION") _x000D_
    {_x000D_
      return; //don't close dropdown if i select option_x000D_
    }_x000D_
    $(this).toggleClass('multiple_select_active'); //close dropdown if click inside <select> box_x000D_
});_x000D_
$(".multiple_select").on('blur', function(e) {_x000D_
    $(this).removeClass('multiple_select_active'); //close dropdown if click outside <select>_x000D_
});_x000D_
 _x000D_
$('.multiple_select option').mousedown(function(e) { //no ctrl to select multiple_x000D_
    e.preventDefault(); _x000D_
    $(this).prop('selected', $(this).prop('selected') ? false : true); //set selected options on click_x000D_
    $(this).parent().change(); //trigger change event_x000D_
});_x000D_
_x000D_
 _x000D_
 $("#myFilter").on('change', function() {_x000D_
      var selected = $("#myFilter").val().toString(); //here I get all options and convert to string_x000D_
      var document_style = document.documentElement.style;_x000D_
      if(selected !== "")_x000D_
        document_style.setProperty('--text', "'Selected: "+selected+"'");_x000D_
      else_x000D_
        document_style.setProperty('--text', "'Select values'");_x000D_
 });
_x000D_
:root_x000D_
{_x000D_
 --text: "Select values";_x000D_
}_x000D_
.multiple_select_x000D_
{_x000D_
 height: 18px;_x000D_
 width: 90%;_x000D_
 overflow: hidden;_x000D_
 -webkit-appearance: menulist;_x000D_
 position: relative;_x000D_
}_x000D_
.multiple_select::before_x000D_
{_x000D_
 content: var(--text);_x000D_
 display: block;_x000D_
  margin-left: 5px;_x000D_
  margin-bottom: 2px;_x000D_
}_x000D_
.multiple_select_active_x000D_
{_x000D_
 overflow: visible !important;_x000D_
}_x000D_
.multiple_select option_x000D_
{_x000D_
 display: none;_x000D_
    height: 18px;_x000D_
 background-color: white;_x000D_
}_x000D_
.multiple_select_active option_x000D_
{_x000D_
 display: block;_x000D_
}_x000D_
_x000D_
.multiple_select option::before {_x000D_
  content: "\2610";_x000D_
}_x000D_
.multiple_select option:checked::before {_x000D_
  content: "\2611";_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<select id="myFilter" class="multiple_select" multiple>_x000D_
  <option>A</option>_x000D_
  <option>B</option>_x000D_
  <option>C</option>_x000D_
  <option>D</option>_x000D_
  <option>E</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

Turning a Comma Separated string into individual rows

Nice to see that it have been solved in the 2016 version, but for all of those that is not on that, here are two generalized and simplified versions of the methods above.

The XML-method is shorter, but of course requires the string to allow for the xml-trick (no 'bad' chars.)

XML-Method:

create function dbo.splitString(@input Varchar(max), @Splitter VarChar(99)) returns table as
Return
    SELECT Split.a.value('.', 'VARCHAR(max)') AS Data FROM
    ( SELECT CAST ('<M>' + REPLACE(@input, @Splitter, '</M><M>') + '</M>' AS XML) AS Data 
    ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a); 

Recursive method:

create function dbo.splitString(@input Varchar(max), @Splitter Varchar(99)) returns table as
Return
  with tmp (DataItem, ix) as
   ( select @input  , CHARINDEX('',@Input)  --Recu. start, ignored val to get the types right
     union all
     select Substring(@input, ix+1,ix2-ix-1), ix2
     from (Select *, CHARINDEX(@Splitter,@Input+@Splitter,ix+1) ix2 from tmp) x where ix2<>0
   ) select DataItem from tmp where ix<>0

Function in action

Create table TEST_X (A int, CSV Varchar(100));
Insert into test_x select 1, 'A,B';
Insert into test_x select 2, 'C,D';

Select A,data from TEST_X x cross apply dbo.splitString(x.CSV,',') Y;

Drop table TEST_X

XML-METHOD 2: Unicode Friendly (Addition courtesy of Max Hodges) create function dbo.splitString(@input nVarchar(max), @Splitter nVarchar(99)) returns table as Return SELECT Split.a.value('.', 'NVARCHAR(max)') AS Data FROM ( SELECT CAST ('<M>' + REPLACE(@input, @Splitter, '</M><M>') + '</M>' AS XML) AS Data ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a);

File 'app/hero.ts' is not a module error in the console, where to store interfaces files in directory structure with angular2?

In my case I had forgotten to save changes to the file 'app/hero.ts', after saving and restarting ng serve the issue was resolved.

Have a div cling to top of screen if scrolled down past it

The trick to make infinity's answer work without the flickering is to put the scroll-check on another div then the one you want to have fixed.

Derived from the code viixii.com uses I ended up using this:

function sticky_relocate() {
    var window_top = $(window).scrollTop();
    var div_top = $('#sticky-anchor').offset().top;
    if (window_top > div_top)
        $('#sticky-element').addClass('sticky');
    else
        $('#sticky-element').removeClass('sticky');
}

$(function() {
    $(window).scroll(sticky_relocate);
    sticky_relocate();
});

This way the function is only called once the sticky-anchor is reached and thus won't be removing and adding the '.sticky' class on every scroll event.

Now it adds the sticky class when the sticky-anchor reaches the top and removes it once the sticky-anchor return into view.

Just place an empty div with a class acting like an anchor just above the element you want to have fixed.

Like so:

<div id="sticky-anchor"></div>
<div id="sticky-element">Your sticky content</div>

All credit for the code goes to viixii.com

.append(), prepend(), .after() and .before()

This image displayed below gives a clear understanding and shows the exact difference between .append(), .prepend(), .after() and .before()

jQuery infographic

You can see from the image that .append() and .prepend() adds the new elements as child elements (brown colored) to the target.

And .after() and .before() adds the new elements as sibling elements (black colored) to the target.

Here is a DEMO for better understanding.


EDIT: the flipped versions of those functions:

jQuery insertion infographic, plus flipped versions of the functions

Using this code:

var $target = $('.target');

$target.append('<div class="child">1. append</div>');
$target.prepend('<div class="child">2. prepend</div>');
$target.before('<div class="sibling">3. before</div>');
$target.after('<div class="sibling">4. after</div>');

$('<div class="child flipped">or appendTo</div>').appendTo($target);
$('<div class="child flipped">or prependTo</div>').prependTo($target);
$('<div class="sibling flipped">or insertBefore</div>').insertBefore($target);
$('<div class="sibling flipped">or insertAfter</div>').insertAfter($target);

on this target:

<div class="target">
    This is the target div to which new elements are associated using jQuery
</div>

So although these functions flip the parameter order, each creates the same element nesting:

var $div = $('<div>').append($('<img>'));
var $img = $('<img>').appendTo($('<div>'))

...but they return a different element. This matters for method chaining.

Make error: missing separator

So apparently, all I needed was the "build-essential" package, then to run autoconf first, which made the Makefile.pre.in, then the ./configure then the make which works perfectly...

How do I replace all line breaks in a string with <br /> elements?

Not answering the specific question, but I am sure this will help someone...

If you have output from PHP that you want to render on a web page using JavaScript (perhaps the result of an Ajax request), and you just want to retain white space and line breaks, consider just enclosing the text inside a <pre></pre> block:

var text_with_line_breaks = retrieve_some_text_from_php();
var element = document.querySelectorAll('#output');
element.innerHTML = '<pre>' + text_with_line_breaks + '</pre>';

C# HttpWebRequest The underlying connection was closed: An unexpected error occurred on a send

In 4.0 version of the .Net framework the ServicePointManager.SecurityProtocol only offered two options to set:

  • Ssl3: Secure Socket Layer (SSL) 3.0 security protocol.
  • Tls: Transport Layer Security (TLS) 1.0 security protocol

In the next release of the framework the SecurityProtocolType enumerator got extended with the newer Tls protocols, so if your application can use th 4.5 version you can also use:

  • Tls11: Specifies the Transport Layer Security (TLS) 1.1 security protocol
  • Tls12: Specifies the Transport Layer Security (TLS) 1.2 security protocol.

So if you are on .Net 4.5 change your line

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;

to

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

so that the ServicePointManager will create streams that support Tls12 connections.

Do notice that the enumeration values can be used as flags so you can combine multiple protocols with a logical OR

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | 
                                       SecurityProtocolType.Tls11 |
                                       SecurityProtocolType.Tls12;

Note
Try to keep the number of protocols you support as low as possible and up-to-date with today security standards. Ssll3 is no longer deemed secure and the usage of Tls1.0 SecurityProtocolType.Tls is in decline.

How do I assert equality on two classes without an equals method?

You can use Apache commons lang ReflectionToStringBuilder

You can either specify the attributes you want to test one by one, or better, exclude those you don't want:

String s = new ReflectionToStringBuilder(o, ToStringStyle.SHORT_PREFIX_STYLE)
                .setExcludeFieldNames(new String[] { "foo", "bar" }).toString()

You then compare the two strings as normal. For the point about reflection being slow, I assume this is only for testing, so shouldn't be so important.

HTML5 iFrame Seamless Attribute

I couldn't find anything that met my requirements, hece I came up with this script (depends on jQuery):

https://gist.github.com/invernizzie/95182de86ea9dc5daa80

It will resize the iframe to the viewport size (taking into account wider content). It could use an improvement to use the viewport height instead of the content height, in the case that the former is bigger.

Sending POST parameters with Postman doesn't work, but sending GET parameters does

For me, the server was expect HTTPS requests, but I didn't specify that in the URL. The hook would reach the server, but the body would be empty.

Recursive file search using PowerShell

I use this to find files and then have PowerShell display the entire path of the results:

dir -Path C:\FolderName -Filter FileName.fileExtension -Recurse | %{$_.FullName}

You can always use the wildcard * in the FolderName and/or FileName.fileExtension. For example:

dir -Path C:\Folder* -Filter File*.file* -Recurse | %{$_.FullName}

The above example will search any folder in the C:\ drive beginning with the word Folder. So if you have a folder named FolderFoo and FolderBar PowerShell will show results from both of those folders.

The same goes for the file name and file extension. If you want to search for a file with a certain extension, but don't know the name of the file, you can use:

dir -Path C:\FolderName -Filter *.fileExtension -Recurse | %{$_.FullName}

Or vice versa:

dir -Path C:\FolderName -Filter FileName.* -Recurse | %{$_.FullName}

syntax error: unexpected token <

Just ignore parameter passing as a false in java script functions

Ex:

function getCities(stateId,locationId=false){    

    // Avoid writting locationId= false kind of statements
   /*your code comes here*/

 }

Avoid writting locationId= false kind of statements, As this will give the error in chrome and IE

How to display a list inline using Twitter's Bootstrap

According to the Bootstrap documentation, you need to add the class 'inline' to your list; like this:

<ul class="inline">
    <li>Item one</li>
    <li>Item two</li>
    <li>Item three</li>
</ul>

However, this does not work as there seems to be some CSS missing in the Bootstrap CSS file referring to the class 'inline'. So additionally, add the following lines to your CSS file to make it work:

ul.inline > li, ol.inline > li {
    display: inline-block;
    padding-right: 5px;
    padding-left: 5px;
}

Capture key press without placing an input element on the page?

jQuery also has an excellent implementation that's incredibly easy to use. Here's how you could implement this functionality across browsers:

$(document).keypress(function(e){
    var checkWebkitandIE=(e.which==26 ? 1 : 0);
    var checkMoz=(e.which==122 && e.ctrlKey ? 1 : 0);

    if (checkWebkitandIE || checkMoz) $("body").append("<p>ctrl+z detected!</p>");
});

Tested in IE7,Firefox 3.6.3 & Chrome 4.1.249.1064

Another way of doing this is to use the keydown event and track the event.keyCode. However, since jQuery normalizes keyCode and charCode using event.which, their spec recommends using event.which in a variety of situations:

$(document).keydown(function(e){
if (e.keyCode==90 && e.ctrlKey)
    $("body").append("<p>ctrl+z detected!</p>");
});

How to sort a file, based on its numerical values for a field?

Well, most other answers here refer to

sort -n

However, I'm not sure this works for negative numbers. Here are the results I get with sort version 6.10 on Fedora 9.

Input file:

-0.907928466796875
-0.61614990234375
1.135406494140625
0.48614501953125
-0.4140167236328125

Output:

-0.4140167236328125
0.48614501953125
-0.61614990234375
-0.907928466796875
1.135406494140625

Which is obviously not ordered by numeric value.

Then, I guess that a more precise answer would be to use sort -n but only if all the values are positive.

P.S.: Using sort -g returns just the same results for this example

Edit:

Looks like the locale settings affect how the minus sign affects the order (see here). In order to get proper results I just did:

LC_ALL=C sort -n filename.txt

Difference between framework vs Library vs IDE vs API vs SDK vs Toolkits?

Consider Android Development:

IDE: Eclipse etc..

Library: android.app.Activity library (Class with all code)

API: Interface basically all functions with which we call

SDK: The Android SDK provides you the API libraries and developer tools necessary to build, test, and debug apps for Android (----tools - DDMS,Emulator ----platforms - Android OS versions, ----platform-tools - ADB, ----API docs)

ToolKit: Could be ADT Bundle

Framework: Big library but more of architecture-oriented

How do I create a user with the same privileges as root in MySQL/MariaDB?

% mysql --user=root mysql
CREATE USER 'monty'@'localhost' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'monty'@'localhost' WITH GRANT OPTION;
CREATE USER 'monty'@'%' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'monty'@'%' WITH GRANT OPTION;
CREATE USER 'admin'@'localhost';
GRANT RELOAD,PROCESS ON *.* TO 'admin'@'localhost';
CREATE USER 'dummy'@'localhost';
FLUSH PRIVILEGES;

Adding Buttons To Google Sheets and Set value to Cells on clicking

You can insert an image that looks like a button. Then attach a script to the image.

  • INSERT menu
  • Image

Insert Image

You can insert any image. The image can be edited in the spreadsheet

Edit Image

Image of a Button

Image of Button

Assign a function name to an image:

Assign Function

How can multiple rows be concatenated into one in Oracle without creating a stored procedure?

Easy:

SELECT question_id, wm_concat(element_id) as elements
FROM   questions
GROUP BY question_id;

Pesonally tested on 10g ;-)

From http://www.oracle-base.com/articles/10g/StringAggregationTechniques.php

How to get the onclick calling object?

pass in this in the inline click handler

<a href="123.com" onclick="click123(this);">link</a>

or use event.target in the function (according to the W3C DOM Level 2 Event model)

function click123(event)
{
    var a = event.target;
}

But of course, IE is different, so the vanilla JavaScript way of handling this is

function doSomething(e) {
    var targ;
    if (!e) var e = window.event;
    if (e.target) targ = e.target;
    else if (e.srcElement) targ = e.srcElement;
    if (targ.nodeType == 3) // defeat Safari bug
        targ = targ.parentNode;
}

or less verbose

function doSomething(e) {

    e = e || window.event;
    var targ = e.target || e.srcElement || e;
    if (targ.nodeType == 3) targ = targ.parentNode; // defeat Safari bug
}

where e is the event object that is passed to the function in browsers other than IE.

If you're using jQuery though, I would strongly encourage unobtrusive JavaScript and use jQuery to bind event handlers to elements.

Get yesterday's date using Date

Try this;

   public String toDate() {
       DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
       Calendar cal = Calendar.getInstance();
       cal.add(Calendar.DATE, -1);
       return dateFormat.format(cal.getTime());
  }

Render basic HTML view?

res.sendFile(__dirname + '/public/login.html');

Add number of days to a date

I know this is an old question, but for PHP <5.3 you could try this:

$date = '05/07/2013';
$add_days = 7;
$date = date('Y-m-d',strtotime($date) + (24*3600*$add_days)); //my preferred method
//or
$date = date('Y-m-d',strtotime($date.' +'.$add_days.' days');

Android overlay a view ontop of everything?

You can use bringToFront:

    View view=findViewById(R.id.btnStartGame);
    view.bringToFront();

using batch echo with special characters

In order to use special characters, such as '>' on Windows with echo, you need to place a special escape character before it.

For instance

echo A->B

will not work since '>' has to be escaped by '^':

 echo A-^>B

See also escape sequences. enter image description here

There is a short batch file, which prints a basic set of special character and their escape sequences.

How do I redirect users after submit button click?

// similar behavior as an HTTP redirect
window.location.replace("http://stackoverflow.com/SpecificAction.php");

// similar behavior as clicking on a link
window.location.href = "http://stackoverflow.com/SpecificAction.php";

Python loop to run for certain amount of seconds

try this:

import time
import os

n = 0
for x in range(10): #enter your value here
    print(n)
    time.sleep(1) #to wait a second
    os.system('cls') #to clear previous number
                     #use ('clear') if you are using linux or mac!
    n = n + 1

Explanation of JSONB introduced by PostgreSQL

  • hstore is more of a "wide column" storage type, it is a flat (non-nested) dictionary of key-value pairs, always stored in a reasonably efficient binary format (a hash table, hence the name).
  • json stores JSON documents as text, performing validation when the documents are stored, and parsing them on output if needed (i.e. accessing individual fields); it should support the entire JSON spec. Since the entire JSON text is stored, its formatting is preserved.
  • jsonb takes shortcuts for performance reasons: JSON data is parsed on input and stored in binary format, key orderings in dictionaries are not maintained, and neither are duplicate keys. Accessing individual elements in the JSONB field is fast as it doesn't require parsing the JSON text all the time. On output, JSON data is reconstructed and initial formatting is lost.

IMO, there is no significant reason for not using jsonb once it is available, if you are working with machine-readable data.

How to change the bootstrap primary color?

Any element with 'primay' tag has the color @brand-primary. One of the options to change it is adding a customized css file like below:

_x000D_
_x000D_
.my-primary{_x000D_
  color: lightYellow ;_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.my-primary:focus, .my-primary:hover{_x000D_
  color: yellow ;_x000D_
  background-color: darkRed;_x000D_
}_x000D_
_x000D_
a.navbar-brand {_x000D_
  color: lightYellow ;_x000D_
}_x000D_
_x000D_
.navbar-brand:hover{_x000D_
  color: yellow;_x000D_
}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<div class="container">_x000D_
  <br>_x000D_
  <nav class="navbar navbar-dark bg-primary mb-3">_x000D_
    <div class="container">_x000D_
      <a class="navbar-brand" href="/">Default (navbar-dark  bg-primary)</a>_x000D_
    </div>_x000D_
  </nav>_x000D_
  <button type="button" class="btn btn-primary">Default (btn btn-primary)</button>_x000D_
  </div>_x000D_
_x000D_
_x000D_
<br>_x000D_
_x000D_
<div class="container">_x000D_
  <nav class="navbar my-primary mb-3">_x000D_
    <div class="container">_x000D_
      <a class="navbar-brand" href="/">Customized (my-primary)</a>_x000D_
    </div>_x000D_
  </nav>_x000D_
  <button type="button" class="btn my-primary">Customized (btn my-primary)</button>_x000D_
  </div>
_x000D_
_x000D_
_x000D_

For more about customized css files with bootstrap, here is a helpful link: https://bootstrapbay.com/blog/bootstrap-button-styles/ .

Default Values to Stored Procedure in Oracle

Default values are only used if the arguments are not specified. In your case you did specify the arguments - both were supplied, with a value of NULL. (Yes, in this case NULL is considered a real value :-). Try:

EXEC TEST()

Share and enjoy.

Addendum: The default values for procedure parameters are certainly buried in a system table somewhere (see the SYS.ALL_ARGUMENTS view), but getting the default value out of the view involves extracting text from a LONG field, and is probably going to prove to be more painful than it's worth. The easy way is to add some code to the procedure:

CREATE OR REPLACE PROCEDURE TEST(X IN VARCHAR2 DEFAULT 'P',
                                 Y IN NUMBER DEFAULT 1)
AS
  varX VARCHAR2(32767) := NVL(X, 'P');
  varY NUMBER          := NVL(Y, 1);
BEGIN
  DBMS_OUTPUT.PUT_LINE('X=' || varX || ' -- ' || 'Y=' || varY);
END TEST;

Invalid column name sql error

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Data.SqlClient;
using System.Data;

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void btnAdd_Click(object sender, RoutedEventArgs e)
        {
            SqlConnection conn = new SqlConnection(@"Data Source=WKS09\SQLEXPRESS;Initial Catalog = StudentManagementSystem;Integrated Security=True");
            SqlCommand insert = new SqlCommand("insert into dbo.StudentRegistration(ID, Name,Age,DateOfBirth,Email,Comment) values(@ID, @Name,@Age,@DateOfBirth,@mail,@comment)", conn);
            insert.Parameters.AddWithValue("@ID", textBox1.Text);
            insert.Parameters.AddWithValue("@Name", textBox2.Text);
            insert.Parameters.AddWithValue("@Age", textBox3.Text);
            insert.Parameters.AddWithValue("@DateOfBirth", textBox4.Text);
            insert.Parameters.AddWithValue("@mail", textBox5.Text);
            insert.Parameters.AddWithValue("@comment", textBox6.Text);

            if (textBox1.Text == string.Empty)
            {
                MessageBox.Show("ID Cannot be Null");
                return;
            }
            else if (textBox2.Text == string.Empty)
            {
                MessageBox.Show("Name Cannot be Null");
                return;
            }


            try
            {
                conn.Open();
                insert.ExecuteNonQuery();
                MessageBox.Show("Register done !");
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error" + ex.Message);
                conn.Close();
            }
        }

        private void btnRetrive_Click(object sender, RoutedEventArgs e)
        {
            bool temp = false;
            SqlConnection con = new SqlConnection("server=WKS09\\SQLEXPRESS;database=StudentManagementSystem;Trusted_Connection=True");
            con.Open();
            SqlCommand cmd = new SqlCommand("select * from dbo.StudentRegistration where ID = '" + textBox1.Text.Trim() + "'", con);
            SqlDataReader dr = cmd.ExecuteReader();
            while (dr.Read())
            {
                textBox2.Text = dr.GetString(1);
                textBox3.Text = dr.GetInt32(2).ToString(); 
                textBox4.Text = dr.GetDateTime(3).ToString();
                textBox5.Text = dr.GetString(4);
                textBox6.Text = dr.GetString(5);
                temp = true;
            }
            if (temp == false)
                MessageBox.Show("not found");
            con.Close();
        }

        private void btnClear_Click(object sender, RoutedEventArgs e)
        {
            SqlConnection connection = new SqlConnection("Data Source=WKS09\\SQLEXPRESS;Initial Catalog = StudentManagementSystem;Integrated Security=True");
            string sqlStatement = "DELETE FROM dbo.StudentRegistration WHERE ID = @ID";
            try
            {
                connection.Open();
                SqlCommand cmd = new SqlCommand(sqlStatement, connection);
                cmd.Parameters.AddWithValue("@ID", textBox1.Text);
                cmd.CommandType = CommandType.Text;
                cmd.ExecuteNonQuery();
                MessageBox.Show("Done");
            }
            finally
            {
                Clear();
                connection.Close();
            }
        }

        public void Clear()
        {
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
        }
    }
}

How to select data of a table from another database in SQL Server?

Using Microsoft SQL Server Management Studio you can create Linked Server. First make connection to current (local) server, then go to Server Objects > Linked Servers > context menu > New Linked Server. In window New Linked Server you have to specify desired server name for remote server, real server name or IP address (Data Source) and credentials (Security page).

And further you can select data from linked server:

select * from [linked_server_name].[database].[schema].[table]