SyntaxFix

Programs & Examples On #Exist db

eXist-db is an open source database management system built using XML technology. It stores XML data according to the XML data model and features efficient, index-based XQuery processing.

How to make div go behind another div?

To answer the question in a general manner:

Using z-index will allow you to control this. see z-index at csstricks.

The element of higher z-index will be displayed on top of elements of lower z-index.

For instance, take the following HTML:

<div id="first">first</div>
<div id="second">second</div>

If I have the following CSS:

#first {
    position: fixed;
    z-index: 2;
}

#second {
    position: fixed;
    z-index: 1;
}

#first wil be on top of #second.

But specifically in your case:

The div element is a child of the div that you wish to put in front. This is not logically possible.

Delimiter must not be alphanumeric or backslash and preg_match

You need a delimiter for your pattern. It should be added at the start and end of the pattern like so:

$pattern = "/My name is '(.*)' and im fine/";  // With / as a delimeter

How do I make a Windows batch script completely silent?

Copies a directory named html & all its contents to a destination directory in silent mode. If the destination directory is not present it will still create it.

@echo off
TITLE Copy Folder with Contents

set SOURCE=C:\labs
set DESTINATION=C:\Users\MyUser\Desktop\html

xcopy %SOURCE%\html\* %DESTINATION%\* /s /e /i /Y >NUL

  1. /S Copies directories and subdirectories except empty ones.

  2. /E Copies directories and subdirectories, including empty ones. Same as /S /E. May be used to modify /T.

  3. /I If destination does not exist and copying more than one file, assumes that destination must be a directory.

  4. /Y Suppresses prompting to confirm you want to overwrite an existing destination file.

How to set connection timeout with OkHttp

For Retrofit retrofit:2.0.0-beta4 the code goes as follows:

OkHttpClient client = new OkHttpClient.Builder()
    .addInterceptor(logging)
    .connectTimeout(30, TimeUnit.SECONDS)
    .readTimeout(30, TimeUnit.SECONDS)
    .writeTimeout(30, TimeUnit.SECONDS)
    .build();

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("http://api.yourapp.com/")
    .addConverterFactory(GsonConverterFactory.create())
    .client(client)
    .build();

Splitting String with delimiter

How are you calling split? It works like this:

def values = '1182-2'.split('-')
assert values[0] == '1182'
assert values[1] == '2'

vector vs. list in STL

Any time you cannot have iterators invalidated.

http://localhost:50070 does not work HADOOP

After installing and configuring Hadoop, you can quickly run the command netstat -tulpn

to find the ports open. In the new version of Hadoop 3.1.3 the ports are as follows:-

localhost:8042 Hadoop, localhost:9870 HDFS, localhost:8088 YARN

Extracting text from HTML file using Python

Found myself facing just the same problem today. I wrote a very simple HTML parser to strip incoming content of all markups, returning the remaining text with only a minimum of formatting.

from HTMLParser import HTMLParser
from re import sub
from sys import stderr
from traceback import print_exc

class _DeHTMLParser(HTMLParser):
    def __init__(self):
        HTMLParser.__init__(self)
        self.__text = []

    def handle_data(self, data):
        text = data.strip()
        if len(text) > 0:
            text = sub('[ \t\r\n]+', ' ', text)
            self.__text.append(text + ' ')

    def handle_starttag(self, tag, attrs):
        if tag == 'p':
            self.__text.append('\n\n')
        elif tag == 'br':
            self.__text.append('\n')

    def handle_startendtag(self, tag, attrs):
        if tag == 'br':
            self.__text.append('\n\n')

    def text(self):
        return ''.join(self.__text).strip()


def dehtml(text):
    try:
        parser = _DeHTMLParser()
        parser.feed(text)
        parser.close()
        return parser.text()
    except:
        print_exc(file=stderr)
        return text


def main():
    text = r'''
        <html>
            <body>
                <b>Project:</b> DeHTML<br>
                <b>Description</b>:<br>
                This small script is intended to allow conversion from HTML markup to 
                plain text.
            </body>
        </html>
    '''
    print(dehtml(text))


if __name__ == '__main__':
    main()

Pandas DataFrame Groupby two columns and get counts

Should you want to add a new column (say 'count_column') containing the groups' counts into the dataframe:

df.count_column=df.groupby(['col5','col2']).col5.transform('count')

(I picked 'col5' as it contains no nan)

Android studio doesn't list my phone under "Choose Device"

I face Same problem. In my case i solved this by following some steps.

  1. click attached debugger to android process (It located In android tools inside run button)

  2. if see adb not responding error dialog. then click restart of dialogue button.

  3. Now you can see which device is connected. now close this window.

  4. again press run button. Now you find your targeted device or emulator which is connected.

Hopefully it helps you.

How to convert Nvarchar column to INT

CONVERT takes the column name, not a string containing the column name; your current expression tries to convert the string A.my_NvarcharColumn to an integer instead of the column content.

SELECT convert (int, N'A.my_NvarcharColumn') FROM A;

should instead be

SELECT convert (int, A.my_NvarcharColumn) FROM A;

Simple SQLfiddle here.

Turning error reporting off php

Does this work?

display_errors = Off

Also, what version of php are you using?

How to remove "index.php" in codeigniter's path

There are two way to solve index.php in url path for codeigniter

1:In config/config.php Change code :

$config['index_page'] = 'index.php';

to

$config['index_page'] = '';

2:Create .htacess in root path if not created,Copy the following code:-

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]
</IfModule>

Save it and then check in your Apache Configuration rewrite_module OR mod_rewrite is Enabled.If not then please enabled. (Best Approach)!

What does "if (rs.next())" mean?

As to the concrete problem with that SQLException, you need to replace

ResultSet rs = stmt.executeQuery(sql);

by

ResultSet rs = stmt.executeQuery();

because you're using the PreparedStatement subclass instead of Statement. When using PreparedStatement, you've already passed in the SQL string to Connection#prepareStatement(). You just have to set the parameters on it and then call executeQuery() method directly without re-passing the SQL string.

See also:

As to the concrete question about rs.next(), it shifts the cursor to the next row of the result set from the database and returns true if there is any row, otherwise false. In combination with the if statement (instead of the while) this means that the programmer is expecting or interested in only one row, the first row.

See also:

How to implement Enums in Ruby?

I know it's been a long time since the guy posted this question, but I had the same question and this post didn't give me the answer. I wanted an easy way to see what the number represents, easy comparison, and most of all ActiveRecord support for lookup using the column representing the enum.

I didn't find anything, so I made an awesome implementation called yinum which allowed everything I was looking for. Made ton of specs, so I'm pretty sure it's safe.

Some example features:

COLORS = Enum.new(:COLORS, :red => 1, :green => 2, :blue => 3)
=> COLORS(:red => 1, :green => 2, :blue => 3)
COLORS.red == 1 && COLORS.red == :red
=> true

class Car < ActiveRecord::Base    
  attr_enum :color, :COLORS, :red => 1, :black => 2
end
car = Car.new
car.color = :red / "red" / 1 / "1"
car.color
=> Car::COLORS.red
car.color.black?
=> false
Car.red.to_sql
=> "SELECT `cars`.* FROM `cars` WHERE `cars`.`color` = 1"
Car.last.red?
=> true

How to connect android emulator to the internet

I had this issue due to a network change after I opened the emulator. If you change your WiFi after you start the emulator, you only need to restart the emulator to get internet access

How to "pull" from a local branch into another one?

What you are looking for is merging.

git merge master

With pull you fetch changes from a remote repository and merge them into the current branch.

Check whether number is even or odd

Another easy way to do it without using if/else condition (works for both positive and negative numbers):

int n = 8;
List<String> messages = Arrays.asList("even", "odd");

System.out.println(messages.get(Math.abs(n%2)));

For an Odd no., the expression will return '1' as remainder, giving

messages.get(1) = 'odd' and hence printing 'odd'

else, 'even' is printed when the expression comes up with result '0'

Superscript in markdown (Github flavored)?

Comments about previous answers

The universal solution is using the HTML tag <sup>, as suggested in the main answer.
However, the idea behind Markdown is precisely to avoid the use of such tags:
The document should look nice as plain text, not only when rendered.

Another answer proposes using Unicode characters, which makes the document look nice as a plain text document but could reduce compatibility.

Finally, I would like to remember the simplest solution for some documents: the character ^.
Some Markdown implementation (e.g. MacDown in macOS) interprets the caret as an instruction for superscript.

Ex.
Sin^2 + Cos^2 = 1
Clearly, Stack Overflow does not interpret the caret as a superscript instruction. However, the text is comprehensible, and this is what really matters when using Markdown.

react hooks useEffect() cleanup for only componentWillUnmount?

 
function LegoComponent() {

  const [lego, setLegos] = React.useState([])

  React.useEffect(() => {
    let isSubscribed = true
    fetchLegos().then( legos=> {
      if (isSubscribed) {
        setLegos(legos)
      }
    })
    return () => isSubscribed = false
  }, []);

  return (
    <ul>
    {legos.map(lego=> <li>{lego}</li>)}
    </ul>
  )
}

In the code above, the fetchLegos function returns a promise. We can “cancel” the promise by having a conditional in the scope of useEffect, preventing the app from setting state after the component has unmounted.

Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function.

Open multiple Eclipse workspaces on the Mac

Based on a previous answer that helped me, but different directory:

cd /Applications/Eclipse.app/Contents/MacOS
./eclipse &

Thanks

Get model's fields in Django

Now there is special method - get_fields()

    >>> from django.contrib.auth.models import User
    >>> User._meta.get_fields()

It accepts two parameters that can be used to control which fields are returned:

  • include_parents

    True by default. Recursively includes fields defined on parent classes. If set to False, get_fields() will only search for fields declared directly on the current model. Fields from models that directly inherit from abstract models or proxy classes are considered to be local, not on the parent.

  • include_hidden

    False by default. If set to True, get_fields() will include fields that are used to back other field’s functionality. This will also include any fields that have a related_name (such as ManyToManyField, or ForeignKey) that start with a “+”

How to load external webpage in WebView

Please use this code:-

Main.Xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:background="@drawable/background">
    <RelativeLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content" android:background="@drawable/top_heading"
        android:id="@+id/rlayout1">
        <TextView android:layout_width="wrap_content"
            android:layout_centerVertical="true" android:layout_centerHorizontal="true"
            android:textColor="#ffffff" android:textSize="22dip"
            android:textStyle="bold" android:layout_height="wrap_content"
            android:text="More Information" android:id="@+id/txtviewfbdisplaytitle" />
    </RelativeLayout>
    <RelativeLayout android:layout_width="fill_parent"
        android:layout_height="fill_parent" android:layout_below="@+id/rlayout1"
        android:id="@+id/rlayout2">
        <WebView android:id="@+id/webview1" android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_weight="1.0" />
    </RelativeLayout>
</RelativeLayout>

MainActivity.Java

public class MainActivity extends Activity {
    private class MyWebViewClient extends WebViewClient {
          @Override
          public boolean shouldOverrideUrlLoading(WebView view, String url) {
              view.loadUrl(url);
              return true;
          }
    }
    Button btnBack;
    WebView webview;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        webview=(WebView)findViewById(R.id.webview1);
        webview.setWebViewClient(new MyWebViewClient());
        openURL();
    }

     /** Opens the URL in a browser */
    private void openURL() {
        webview.loadUrl("http://www.google.com");
        webview.requestFocus();
    }
}

Try this code if any query ask me.

WMI "installed" query different from add/remove programs list?

Besides the most commonly known registry key for installed programs:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall

wmic command and the add/remove programs also query another registry key:

HKEY_CLASSES_ROOT\Installer\Products

Software name shown in the list is read from the Value of a Data entry within this key called: ProductName

Removing the registry key for a certain product from both of the above locations will keep it from showing in the add/remove programs list. This is not a method to uninstall programs, it will just remove the entry from what's known to windows as installed software.

Since, by using this method you would lose the chance of using the Remove button from the add/remove list to cleanly remove the software from your system; it's recommended to export registry keys to a file before you delete them. In future, if you decided to bring that item back to the list, you would simply run the registry file you stored.

OS X Terminal UTF-8 issues

Short versatile answer (fits to other national languages, even Lithuanian or Russian)

  • open Terminal
  • edit .profile in home directory - nano .profile or in Catalina or newer nano .zshenv
  • add line export LC_ALL=en_US.UTF-8
  • press Ctrl+x and Y (exit and save)

This solved for me even small country rare national characters. You may need to close and open Terminal to make changes effective.

Also if you like Linux behavior (use lot of Alt shortcuts like Alt+. or Alt+, in mc) then you should disable Mac style Option key function: Terminal->Preferences->Profiles->Keyboard and check box: Use Option as Meta key

$location / switching between html5 and hashbang mode / link rewriting

Fur future readers, if you are using Angular 1.6, you also need to change the hashPrefix:

appModule.config(['$locationProvider', function($locationProvider) {
    $locationProvider.html5Mode(true);
    $locationProvider.hashPrefix('');
}]);

Don't forget to set the base in your HTML <head>:

<head>
    <base href="/">
    ...
</head>

More info about the changelog here.

Postgres: INSERT if does not exist already

The approach with the most upvotes (from John Doe) does somehow work for me but in my case from expected 422 rows i get only 180. I couldn't find anything wrong and there are no errors at all, so i looked for a different simple approach.

Using IF NOT FOUND THEN after a SELECT just works perfectly for me.

(described in PostgreSQL Documentation)

Example from documentation:

SELECT * INTO myrec FROM emp WHERE empname = myname;
IF NOT FOUND THEN
  RAISE EXCEPTION 'employee % not found', myname;
END IF;

mysql is not recognised as an internal or external command,operable program or batch

Simply type in command prompt :

set path=%PATH%;D:\xampp\mysql\bin;

Here my path started from D so I used D: , you can use C: or E:

enter image description here

Intercept page exit event

Similar to Ghommey's answer, but this also supports old versions of IE and Firefox.

window.onbeforeunload = function (e) {
  var message = "Your confirmation message goes here.",
  e = e || window.event;
  // For IE and Firefox
  if (e) {
    e.returnValue = message;
  }

  // For Safari
  return message;
};

error: No resource identifier found for attribute 'adSize' in package 'com.google.example' main.xml

I added in android.support.design.widget.NawigationView this parameter:

android:layout_gravity="start"

And problem was solved.

MVC Calling a view from a different controller

I'm not really sure if I got your question right. Maybe something like

public class CommentsController : Controller
{
    [HttpPost]
    public ActionResult WriteComment(CommentModel comment)
    {
        // Do the basic model validation and other stuff
        try
        {
            if (ModelState.IsValid )
            {
                 // Insert the model to database like:
                 db.Comments.Add(comment);
                 db.SaveChanges();

                 // Pass the comment's article id to the read action
                 return RedirectToAction("Read", "Articles", new {id = comment.ArticleID});
            }
        }
        catch ( Exception e )
        {
             throw e;
        }
        // Something went wrong
        return View(comment);

    }
}


public class ArticlesController : Controller
{
    // id is the id of the article
    public ActionResult Read(int id)
    {
        // Get the article from database by id
        var model = db.Articles.Find(id);
        // Return the view
        return View(model);
    }
}

What is the difference between '/' and '//' when used for division?

/ --> Floating point division

// --> Floor division

Lets see some examples in both python 2.7 and in Python 3.5.

Python 2.7.10 vs. Python 3.5 

print (2/3)  ----> 0                   Python 2.7
print (2/3)  ----> 0.6666666666666666  Python 3.5

Python 2.7.10 vs. Python 3.5 

  print (4/2)  ----> 2         Python 2.7
  print (4/2)  ----> 2.0       Python 3.5

Now if you want to have (in python 2.7) same output as in python 3.5, you can do the following:

Python 2.7.10 

from __future__ import division
print (2/3)  ----> 0.6666666666666666   #Python 2.7
print (4/2)  ----> 2.0                  #Python 2.7

Where as there is no differece between Floor division in both python 2.7 and in Python 3.5

138.93//3 ---> 46.0        #Python 2.7
138.93//3 ---> 46.0        #Python 3.5
4//3      ---> 1           #Python 2.7
4//3      ---> 1           #Python 3.5

Javascript Get Element by Id and set the value

try like below it will work...

<html>
<head>
<script>
function displayResult(element)
{
document.getElementById(element).value = 'hi';
}
</script>
</head>
<body>

<textarea id="myTextarea" cols="20">
BYE
</textarea>
<br>

<button type="button" onclick="displayResult('myTextarea')">Change</button>

</body>
</html>

Difference between malloc and calloc?

Number of blocks:
malloc() assigns single block of requested memory,
calloc() assigns multiple blocks of the requested memory

Initialization:
malloc() - doesn't clear and initialize the allocated memory.
calloc() - initializes the allocated memory by zero.

Speed:
malloc() is fast.
calloc() is slower than malloc().

Arguments & Syntax:
malloc() takes 1 argument:

  1. bytes

    • The number of bytes to be allocated

calloc() takes 2 arguments:

  1. length

    • the number of blocks of memory to be allocated

  2. bytes

    • the number of bytes to be allocated at each block of memory
void *malloc(size_t bytes);         
void *calloc(size_t length, size_t bytes);

Manner of memory Allocation:
The malloc function assigns memory of the desired 'size' from the available heap.
The calloc function assigns memory that is the size of what’s equal to ‘num *size’.

Meaning on name:
The name malloc means "memory allocation".
The name calloc means "contiguous allocation".

Polynomial time and exponential time

polynomial time O(n)^k means Number of operations are proportional to power k of the size of input

exponential time O(k)^n means Number of operations are proportional to the exponent of the size of input

java.lang.IllegalArgumentException: contains a path separator

You cannot use path with directory separators directly, but you will have to make a file object for every directory.

NOTE: This code makes directories, yours may not need that...

File file= context.getFilesDir();
file.mkdir();

String[] array=filePath.split("/");
for(int t=0; t< array.length -1 ;t++)
{
    file=new File(file,array[t]);
    file.mkdir();
}

File f=new File(file,array[array.length-1]);

RandomAccessFileOutputStream rvalue = new RandomAccessFileOutputStream(f,append);

How to convert number to words in java

You probably don't need this any more, but I recently wrote a java class to do this. Apparently Yanick Rochon did something similar. It will convert numbers up to 999 Novemdecillion (999*10^60). It could do more if I knew what came after Novemdecillion, but I would be willing to bet it's unnecessary. Just feed the number as a string in cents. The output is also grammatically correct.

Here is a link to the Bitbucket Repo

How to comment in Vim's config files: ".vimrc"?

 
"This is a comment in vimrc. It does not have a closing quote

Source: http://vim.wikia.com/wiki/Backing_up_and_commenting_vimrc

The remote end hung up unexpectedly while git cloning

The http.postBuffer trick did not work for me. However:

For others experiencing this problem, it may be an issue with GnuTLS. If you set Verbose mode, you may see the underlying error look something along the lines of the code below.

Unfortunately, my only solution so far is to use SSH.

I've seen a solution posted elsewhere to compile Git with OpenSSL instead of GnuTLS. There is an active bug report for the issue here.

GIT_CURL_VERBOSE=1 git clone https://github.com/django/django.git

Cloning into 'django'...
* Couldn't find host github.com in the .netrc file; using defaults
* About to connect() to github.com port 443 (#0)
*   Trying 192.30.252.131... * Connected to github.com (192.30.252.131) port 443 (#0)
* found 153 certificates in /etc/ssl/certs/ca-certificates.crt
*    server certificate verification OK
*    common name: github.com (matched)
*    server certificate expiration date OK
*    server certificate activation date OK
*    certificate public key: RSA
*    certificate version: #3
*    subject: 
*    start date: Mon, 10 Jun 2013 00:00:00 GMT
*    expire date: Wed, 02 Sep 2015 12:00:00 GMT
*    issuer: C=US,O=DigiCert Inc,OU=www.digicert.com,CN=DigiCert High Assurance EV CA-1
*    compression: NULL
*    cipher: ARCFOUR-128
*    MAC: SHA1
> GET /django/django.git/info/refs?service=git-upload-pack HTTP/1.1
User-Agent: git/1.8.4
Host: github.com
Accept: */*
Accept-Encoding: gzip

Pragma: no-cache
< HTTP/1.1 200 OK
< Server: GitHub.com
< Date: Thu, 10 Oct 2013 03:28:14 GMT

< Content-Type: application/x-git-upload-pack-advertisement
< Transfer-Encoding: chunked
< Expires: Fri, 01 Jan 1980 00:00:00 GMT
< Pragma: no-cache
< Cache-Control: no-cache, max-age=0, must-revalidate
< Vary: Accept-Encoding
< 
* Connection #0 to host github.com left intact
* Couldn't find host github.com in the .netrc file; using defaults
* About to connect() to github.com port 443 (#0)
*   Trying 192.30.252.131... * connected
* found 153 certificates in /etc/ssl/certs/ca-certificates.crt
* SSL re-using session ID
*    server certificate verification OK
*    common name: github.com (matched)
*    server certificate expiration date OK
*    server certificate activation date OK
*    certificate public key: RSA
*    certificate version: #3
*    subject: 
*    start date: Mon, 10 Jun 2013 00:00:00 GMT
*    expire date: Wed, 02 Sep 2015 12:00:00 GMT
*    issuer: C=US,O=DigiCert Inc,OU=www.digicert.com,CN=DigiCert High Assurance EV CA-1
*    compression: NULL
*    cipher: ARCFOUR-128
*    MAC: SHA1
> POST /django/django.git/git-upload-pack HTTP/1.1
User-Agent: git/1.8.4
Host: github.com
Accept-Encoding: gzip

Content-Type: application/x-git-upload-pack-request
Accept: application/x-git-upload-pack-result
Content-Encoding: gzip
Content-Length: 2299
* upload completely sent off: 2299out of 2299 bytes

< HTTP/1.1 200 OK
< Server: GitHub.com
< Date: Thu, 10 Oct 2013 03:28:15 GMT

< Content-Type: application/x-git-upload-pack-result
< Transfer-Encoding: chunked
< Expires: Fri, 01 Jan 1980 00:00:00 GMT
< Pragma: no-cache
< Cache-Control: no-cache, max-age=0, must-revalidate
< Vary: Accept-Encoding
< 
remote: Counting objects: 232015, done.
remote: Compressing objects: 100% (65437/65437), done.
* GnuTLS recv error (-9): A TLS packet with unexpected length was received.
* Closing connection #0
error: RPC failed; result=56, HTTP code = 200
fatal: The remote end hung up unexpectedly
fatal: early EOF
fatal: index-pack failed

Left/Right float button inside div

You can use justify-content: space-between in .test like so:

_x000D_
_x000D_ 
.test {_x000D_
  display: flex;_x000D_
  justify-content: space-between;_x000D_
  width: 20rem;_x000D_
  border: .1rem red solid;_x000D_
}
_x000D_ 
<div class="test">_x000D_
  <button>test</button>_x000D_
  <button>test</button>_x000D_
</div>
_x000D_
_x000D_
_x000D_

For those who want to use Bootstrap 4 can use justify-content-between:

_x000D_
_x000D_ 
div {_x000D_
  width: 20rem;_x000D_
  border: .1rem red solid;_x000D_
}
_x000D_ 
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet" />_x000D_
<div class="d-flex justify-content-between">_x000D_
  <button>test</button>_x000D_
  <button>test</button>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to find GCD, LCM on a set of numbers

If you can use Java 8 (and actually want to) you can use lambda expressions to solve this functionally:

private static int gcd(int x, int y) {
    return (y == 0) ? x : gcd(y, x % y);
}

public static int gcd(int... numbers) {
    return Arrays.stream(numbers).reduce(0, (x, y) -> gcd(x, y));
}

public static int lcm(int... numbers) {
    return Arrays.stream(numbers).reduce(1, (x, y) -> x * (y / gcd(x, y)));
}

I oriented myself on Jeffrey Hantin's answer, but

  • calculated the gcd functionally
  • used the varargs-Syntax for an easier API (I was not sure if the overload would work correctly, but it does on my machine)
  • transformed the gcd of the numbers-Array into functional syntax, which is more compact and IMO easier to read (at least if you are used to functional programming)

This approach is probably slightly slower due to additional function calls, but that probably won't matter at all for the most use cases.

Is it possible to display inline images from html in an Android TextView?

If you have a look at the documentation for Html.fromHtml(text) you'll see it says:

Any <img> tags in the HTML will display as a generic replacement image which your program can then go through and replace with real images.

If you don't want to do this replacement yourself you can use the other Html.fromHtml() method which takes an Html.TagHandler and an Html.ImageGetter as arguments as well as the text to parse.

In your case you could parse null as for the Html.TagHandler but you'd need to implement your own Html.ImageGetter as there isn't a default implementation.

However, the problem you're going to have is that the Html.ImageGetter needs to run synchronously and if you're downloading images from the web you'll probably want to do that asynchronously. If you can add any images you want to display as resources in your application the your ImageGetter implementation becomes a lot simpler. You could get away with something like:

private class ImageGetter implements Html.ImageGetter {

    public Drawable getDrawable(String source) {
        int id;

        if (source.equals("stack.jpg")) {
            id = R.drawable.stack;
        }
        else if (source.equals("overflow.jpg")) {
            id = R.drawable.overflow;
        }
        else {
            return null;
        }

        Drawable d = getResources().getDrawable(id);
        d.setBounds(0,0,d.getIntrinsicWidth(),d.getIntrinsicHeight());
        return d;
    }
};

You'd probably want to figure out something smarter for mapping source strings to resource IDs though.

What is a callback in java

A callback is some code that you pass to a given method, so that it can be called at a later time.

In Java one obvious example is java.util.Comparator. You do not usually use a Comparator directly; rather, you pass it to some code that calls the Comparator at a later time:

Example:

class CodedString implements Comparable<CodedString> {
    private int code;
    private String text;

    ...

    @Override
    public boolean equals() {
        // member-wise equality
    }

    @Override
    public int hashCode() {
        // member-wise equality 
    }

    @Override
    public boolean compareTo(CodedString cs) {
        // Compare using "code" first, then
        // "text" if both codes are equal.
    }
}

...

public void sortCodedStringsByText(List<CodedString> codedStrings) {
    Comparator<CodedString> comparatorByText = new Comparator<CodedString>() {
        @Override
        public int compare(CodedString cs1, CodedString cs2) {
            // Compare cs1 and cs2 using just the "text" field
        }
    }

    // Here we pass the comparatorByText callback to Collections.sort(...)
    // Collections.sort(...) will then call this callback whenever it
    // needs to compare two items from the list being sorted.
    // As a result, we will get the list sorted by just the "text" field.
    // If we do not pass a callback, Collections.sort will use the default
    // comparison for the class (first by "code", then by "text").
    Collections.sort(codedStrings, comparatorByText);
}

How can I pass a parameter in Action?

If you know what parameter you want to pass, take a Action<T> for the type. Example:

void LoopMethod (Action<int> code, int count) {
     for (int i = 0; i < count; i++) {
         code(i);
     }
}

If you want the parameter to be passed to your method, make the method generic:

void LoopMethod<T> (Action<T> code, int count, T paramater) {
     for (int i = 0; i < count; i++) {
         code(paramater);
     }
}

And the caller code:

Action<string> s = Console.WriteLine;
LoopMethod(s, 10, "Hello World");

Update. Your code should look like:

private void Include(IList<string> includes, Action<string> action)
{
    if (includes != null)
    {
         foreach (var include in includes)
             action(include);
    }
}

public void test()
{
    Action<string> dg = (s) => {
        _context.Cars.Include(s);
    };
    this.Include(includes, dg);
}

HTML input time in 24 format

_x000D_
_x000D_ 
<!DOCTYPE html>_x000D_
<html>_x000D_
    <body>_x000D_
        Time: <input type="time" id="myTime" value="16:32:55">_x000D_
_x000D_
 <p>Click the button to get the time of the time field.</p>_x000D_
_x000D_
 <button onclick="myFunction()">Try it</button>_x000D_
_x000D_
 <p id="demo"></p>_x000D_
_x000D_
 <script>_x000D_
     function myFunction() {_x000D_
         var x = document.getElementById("myTime").value;_x000D_
         document.getElementById("demo").innerHTML = x;_x000D_
     }_x000D_
 </script>_x000D_
    </body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

I found that by setting value field (not just what is given below) time input will be internally converted into the 24hr format.

css h1 - only as wide as the text

This is because your <h1> is the width of the centercol. Specify a width on the <h1> and use margin: 0 auto; if you want it centered.

Or, alternatively, you could float the <h1>, which would make it only exactly as wide as the text.

Why does viewWillAppear not get called when an app comes back from the background?

Swift

Short answer

Use a NotificationCenter observer rather than viewWillAppear.

override func viewDidLoad() {
    super.viewDidLoad()

    // set observer for UIApplication.willEnterForegroundNotification
    NotificationCenter.default.addObserver(self, selector: #selector(willEnterForeground), name: UIApplication.willEnterForegroundNotification, object: nil)

}

// my selector that was defined above
@objc func willEnterForeground() {
    // do stuff
}

Long answer

To find out when an app comes back from the background, use a NotificationCenter observer rather than viewWillAppear. Here is a sample project that shows which events happen when. (This is an adaptation of this Objective-C answer.)

import UIKit
class ViewController: UIViewController {

    // MARK: - Overrides

    override func viewDidLoad() {
        super.viewDidLoad()
        print("view did load")

        // add notification observers
        NotificationCenter.default.addObserver(self, selector: #selector(didBecomeActive), name: UIApplication.didBecomeActiveNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(willEnterForeground), name: UIApplication.willEnterForegroundNotification, object: nil)

    }

    override func viewWillAppear(_ animated: Bool) {
        print("view will appear")
    }

    override func viewDidAppear(_ animated: Bool) {
        print("view did appear")
    }

    // MARK: - Notification oberserver methods

    @objc func didBecomeActive() {
        print("did become active")
    }

    @objc func willEnterForeground() {
        print("will enter foreground")
    }

}

On first starting the app, the output order is:

view did load
view will appear
did become active
view did appear

After pushing the home button and then bringing the app back to the foreground, the output order is:

will enter foreground
did become active

So if you were originally trying to use viewWillAppear then UIApplication.willEnterForegroundNotification is probably what you want.

Note

As of iOS 9 and later, you don't need to remove the observer. The documentation states:

If your app targets iOS 9.0 and later or macOS 10.11 and later, you don't need to unregister an observer in its dealloc method.

How to get the html of a div on another page with jQuery ajax?

 
$.ajax({
  url:href,
  type:'get',
  success: function(data){
   console.log($(data)); 
  }
});

This console log gets an array like object: [meta, title, ,], very strange

You can use JavaScript:

var doc = document.documentElement.cloneNode()
doc.innerHTML = data
$content = $(doc.querySelector('#content'))

Difference between window.location.href, window.location.replace and window.location.assign

These do the same thing:

window.location.assign(url);
window.location = url;
window.location.href = url;

They simply navigate to the new URL. The replace method on the other hand navigates to the URL without adding a new record to the history.

So, what you have read in those many forums is not correct. The assign method does add a new record to the history.

Reference: https://developer.mozilla.org/en-US/docs/Web/API/Window/location

What is time_t ultimately a typedef to?

[root]# cat time.c

#include <time.h>

int main(int argc, char** argv)
{
        time_t test;
        return 0;
}

[root]# gcc -E time.c | grep __time_t

typedef long int __time_t;

It's defined in $INCDIR/bits/types.h through:

# 131 "/usr/include/bits/types.h" 3 4
# 1 "/usr/include/bits/typesizes.h" 1 3 4
# 132 "/usr/include/bits/types.h" 2 3 4

React hooks useState Array

Try to keep your state minimal. There is no need to store 

   const initialValue = [
    { id: 0,value: " --- Select a State ---" }];

as state. Separate the permanent from the changing

const ALL_STATE_VALS = [
    { id: 0,value: " --- Select a State ---" }
    { id: 1, value: "Alabama" },
    { id: 2, value: "Georgia" },
    { id: 3, value: "Tennessee" }
];

Then you can store just the id as your state: 

const StateSelector = () =>{
  const [selectedStateOption, setselectedStateOption] = useState(0);

  return (
    <div>
      <label>Select a State:</label>
      <select>
        {ALL_STATE_VALS.map((option, index) => (
          <option key={option.id} selected={index===selectedStateOption}>{option.value}</option>
        ))}
      </select>
    </div>);
   )
}

How do I ignore files in Subversion?

Also, if you use Tortoise SVN you can do this:

  1. In context menu select "TortoiseSVN", then "Properties"
  2. In appeared window click "New", then "Advanced"
  3. In appeared window opposite to "Property name" select or type "svn:ignore", opposite to "Property value" type desired file name or folder name or file mask (in my case it was "*/target"), click "Apply property recursively"
  4. Ok. Ok.
  5. Commit

Setting the selected value on a Django forms.ChoiceField

You can also do the following. in your form class def:

max_number = forms.ChoiceField(widget = forms.Select(), 
                 choices = ([('1','1'), ('2','2'),('3','3'), ]), initial='3', required = True,)

then when calling the form in your view you can dynamically set both initial choices and choice list.

yourFormInstance = YourFormClass()

yourFormInstance.fields['max_number'].choices = [(1,1),(2,2),(3,3)]
yourFormInstance.fields['max_number'].initial = [1]

Note: the initial values has to be a list and the choices has to be 2-tuples, in my example above i have a list of 2-tuples. Hope this helps.

failed to open stream: HTTP wrapper does not support writeable connections

May this code help you. It works in my case.

$filename = "D:\xampp\htdocs\wordpress/wp-content/uploads/json/2018-10-25.json";
    $fileUrl = "http://localhost/wordpress/wp-content/uploads/json/2018-10-25.json";
    if(!file_exists($filename)):
        $handle = fopen( $filename, 'a' ) or die( 'Cannot open file:  ' . $fileUrl ); //implicitly creates file
        fwrite( $handle, json_encode(array()));
        fclose( $handle );
    endif;
    $response = file_get_contents($filename);
    $tempArray = json_decode($response);
    if(!empty($tempArray)):
        $count = count($tempArray) + 1;
    else:
        $count = 1;
    endif;
    $tempArray[] = array_merge(array("sn." => $count), $data);
    $jsonData = json_encode($tempArray);
    file_put_contents($filename, $jsonData);

Delete default value of an input text on click

Here is an easy way.

#animal represents any buttons from the DOM.
#animal-value is the input id that being targeted.

$("#animal").on('click', function(){
    var userVal = $("#animal-value").val(); // storing that value
    console.log(userVal); // logging the stored value to the console
    $("#animal-value").val('') // reseting it to empty
});

Comparing two byte arrays in .NET

.NET 3.5 and newer have a new public type, System.Data.Linq.Binary that encapsulates byte[]. It implements IEquatable<Binary> that (in effect) compares two byte arrays. Note that System.Data.Linq.Binary also has implicit conversion operator from byte[].

MSDN documentation:System.Data.Linq.Binary

Reflector decompile of the Equals method:

private bool EqualsTo(Binary binary)
{
    if (this != binary)
    {
        if (binary == null)
        {
            return false;
        }
        if (this.bytes.Length != binary.bytes.Length)
        {
            return false;
        }
        if (this.hashCode != binary.hashCode)
        {
            return false;
        }
        int index = 0;
        int length = this.bytes.Length;
        while (index < length)
        {
            if (this.bytes[index] != binary.bytes[index])
            {
                return false;
            }
            index++;
        }
    }
    return true;
}

Interesting twist is that they only proceed to byte-by-byte comparison loop if hashes of the two Binary objects are the same. This, however, comes at the cost of computing the hash in constructor of Binary objects (by traversing the array with for loop :-) ).

The above implementation means that in the worst case you may have to traverse the arrays three times: first to compute hash of array1, then to compute hash of array2 and finally (because this is the worst case scenario, lengths and hashes equal) to compare bytes in array1 with bytes in array 2.

Overall, even though System.Data.Linq.Binary is built into BCL, I don't think it is the fastest way to compare two byte arrays :-|.

CSS: How to remove pseudo elements (after, before,...)?

You need to add a css rule that removes the after content (through a class)..

An update due to some valid comments.

The more correct way to completely remove/disable the :after rule is to use

p.no-after:after{content:none;}

as Gillian Lo Wong answered.

Original answer

You need to add a css rule that removes the after content (through a class).. 

p.no-after:after{content:"";}

and add that class to your p when you want to with this line

$('p').addClass('no-after'); // replace the p selector with what you need...

a working example at : http://www.jsfiddle.net/G2czw/

React.js inline style best practices

Here is the boolean based styling in JSX syntax:

style={{display: this.state.isShowing ? "inherit" : "none"}}

C# equivalent of C++ vector, with contiguous memory?

First of all, stay away from Arraylist or Hashtable. Those classes are to be considered deprecated, in favor of generics. They are still in the language for legacy purposes.

Now, what you are looking for is the List<T> class. Note that if T is a value type you will have contiguos memory, but not if T is a reference type, for obvious reasons.

Group by with union mysql select query

Try this EDITED:

(SELECT COUNT(motorbike.owner_id),owner.name,transport.type FROM transport,owner,motorbike WHERE transport.type='motobike' AND owner.owner_id=motorbike.owner_id AND transport.type_id=motorbike.motorbike_id GROUP BY motorbike.owner_id)

UNION ALL

(SELECT COUNT(car.owner_id),owner.name,transport.type FROM transport,owner,car WHERE transport.type='car' AND owner.owner_id=car.owner_id AND transport.type_id=car.car_id GROUP BY car.owner_id)

Test if something is not undefined in JavaScript

Check if you're response[0] actually exists, the error seems to suggest it doesn't.

creating triggers for After Insert, After Update and After Delete in SQL

(Update: overlooked a fault in the matter, I have corrected)

(Update2: I wrote from memory the code screwed up, repaired it)

(Update3: check on SQLFiddle)

create table Derived_Values
  (
    BusinessUnit nvarchar(100) not null
    ,Questions nvarchar(100) not null
    ,Answer nvarchar(100)
    )

go

ALTER TABLE Derived_Values ADD CONSTRAINT PK_Derived_Values
PRIMARY KEY CLUSTERED (BusinessUnit, Questions);

create table Derived_Values_Test
  (
    BusinessUnit nvarchar(150)
    ,Questions nvarchar(100)
    ,Answer nvarchar(100)
    )

go

CREATE TRIGGER trgAfterUpdate ON  [Derived_Values]
FOR UPDATE
AS  
begin
    declare @BusinessUnit nvarchar(50)
    set @BusinessUnit = 'Updated Record -- After Update Trigger.'

    insert into 
        [Derived_Values_Test]
        --(BusinessUnit,Questions, Answer) 
    SELECT 
        @BusinessUnit + i.BusinessUnit, i.Questions, i.Answer
    FROM 
        inserted i
        inner join deleted d on i.BusinessUnit = d.BusinessUnit
end

go

CREATE TRIGGER trgAfterDelete ON  [Derived_Values]
FOR UPDATE
AS  
begin
    declare @BusinessUnit nvarchar(50)
    set @BusinessUnit = 'Deleted Record -- After Delete Trigger.'

    insert into 
        [Derived_Values_Test]
        --(BusinessUnit,Questions, Answer) 
    SELECT 
        @BusinessUnit + d.BusinessUnit, d.Questions, d.Answer
    FROM 
        deleted d
end

go

insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q11', 'A11')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q12', 'A12')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q21', 'A21')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q22', 'A22')

UPDATE Derived_Values SET Answer='Updated Answers A11' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q11');
UPDATE Derived_Values SET Answer='Updated Answers A12' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q12');
UPDATE Derived_Values SET Answer='Updated Answers A21' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q21');
UPDATE Derived_Values SET Answer='Updated Answers A22' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q22');

delete Derived_Values;

and then:

SELECT * FROM Derived_Values;
go

select * from Derived_Values_Test;


Record Count: 0;

BUSINESSUNIT    QUESTIONS   ANSWER
Updated Record -- After Update Trigger.BU1  Q11 Updated Answers A11
Deleted Record -- After Delete Trigger.BU1  Q11 A11
Updated Record -- After Update Trigger.BU1  Q12 Updated Answers A12
Deleted Record -- After Delete Trigger.BU1  Q12 A12
Updated Record -- After Update Trigger.BU2  Q21 Updated Answers A21
Deleted Record -- After Delete Trigger.BU2  Q21 A21
Updated Record -- After Update Trigger.BU2  Q22 Updated Answers A22
Deleted Record -- After Delete Trigger.BU2  Q22 A22

(Update4: If you want to sync: SQLFiddle)

create table Derived_Values
  (
    BusinessUnit nvarchar(100) not null
    ,Questions nvarchar(100) not null
    ,Answer nvarchar(100)
    )

go

ALTER TABLE Derived_Values ADD CONSTRAINT PK_Derived_Values
PRIMARY KEY CLUSTERED (BusinessUnit, Questions);

create table Derived_Values_Test
  (
    BusinessUnit nvarchar(150) not null
    ,Questions nvarchar(100) not null
    ,Answer nvarchar(100)
    )

go

ALTER TABLE Derived_Values_Test ADD CONSTRAINT PK_Derived_Values_Test
PRIMARY KEY CLUSTERED (BusinessUnit, Questions);

CREATE TRIGGER trgAfterInsert ON  [Derived_Values]
FOR INSERT
AS  
begin
    insert
        [Derived_Values_Test]
        (BusinessUnit,Questions,Answer)
    SELECT 
        i.BusinessUnit, i.Questions, i.Answer
    FROM 
        inserted i
end

go


CREATE TRIGGER trgAfterUpdate ON  [Derived_Values]
FOR UPDATE
AS  
begin
    declare @BusinessUnit nvarchar(50)
    set @BusinessUnit = 'Updated Record -- After Update Trigger.'

    update
        [Derived_Values_Test]
    set
        --BusinessUnit = i.BusinessUnit
        --,Questions = i.Questions
        Answer = i.Answer
    from
        [Derived_Values]
        inner join inserted i 
    on
        [Derived_Values].BusinessUnit = i.BusinessUnit
        and
        [Derived_Values].Questions = i.Questions
end

go

CREATE TRIGGER trgAfterDelete ON  [Derived_Values]
FOR DELETE
AS  
begin
    delete 
        [Derived_Values_Test]
    from
        [Derived_Values_Test]
        inner join deleted d 
    on
        [Derived_Values_Test].BusinessUnit = d.BusinessUnit
        and
        [Derived_Values_Test].Questions = d.Questions
end

go

insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q11', 'A11')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q12', 'A12')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q21', 'A21')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q22', 'A22')

UPDATE Derived_Values SET Answer='Updated Answers A11' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q11');
UPDATE Derived_Values SET Answer='Updated Answers A12' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q12');
UPDATE Derived_Values SET Answer='Updated Answers A21' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q21');
UPDATE Derived_Values SET Answer='Updated Answers A22' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q22');

--delete Derived_Values;

And then:

SELECT * FROM Derived_Values;
go

select * from Derived_Values_Test;


BUSINESSUNIT    QUESTIONS   ANSWER
BU1 Q11 Updated Answers A11
BU1 Q12 Updated Answers A12
BU2 Q21 Updated Answers A21
BU2 Q22 Updated Answers A22

BUSINESSUNIT    QUESTIONS   ANSWER
BU1 Q11 Updated Answers A11
BU1 Q12 Updated Answers A12
BU2 Q21 Updated Answers A21
BU2 Q22 Updated Answers A22

How and where to use ::ng-deep?

USAGE

::ng-deep, >>> and /deep/ disable view encapsulation for specific CSS rules, in other words, it gives you access to DOM elements, which are not in your component's HTML. For example, if you're using Angular Material (or any other third-party library like this), some generated elements are outside of your component's area (such as dialog) and you can't access those elements directly or using a regular CSS way. If you want to change the styles of those elements, you can use one of those three things, for example:

::ng-deep .mat-dialog {
  /* styles here */
}

For now Angular team recommends making "deep" manipulations only with EMULATED view encapsulation.

DEPRECATION

"deep" manipulations are actually deprecated too, BUT it stills working for now, because Angular does pre-processing support (don't rush to refuse ::ng-deep today, take a look at deprecation practices first).

Anyway, before following this way, I recommend you to take a look at disabling view encapsulation approach (which is not ideal too, it allows your styles to leak into other components), but in some cases, it's a better way. If you decided to disable view encapsulation, it's strongly recommended to use specific classes to avoid CSS rules intersection, and finally, avoid a mess in your stylesheets. It's really easy to disable right in the component's .ts file:

@Component({
  selector: '',
  template: '',
  styles: [''],
  encapsulation: ViewEncapsulation.None  // Use to disable CSS Encapsulation for this component
})

You can find more info about the view encapsulation in this article.

How can I get a precise time, for example in milliseconds in Objective-C?

CFAbsoluteTimeGetCurrent() returns the absolute time as a double value, but I don't know what its precision is -- it might only update every dozen milliseconds, or it might update every microsecond, I don't know.

100% height minus header?

For "100% of the browser window", if you mean this literally, you should use fixed positioning. The top, bottom, right, and left properties are then used to offset the divs edges from the respective edges of the viewport:

#nav, #content{position:fixed;top:0px;bottom:0px;}
#nav{left:0px;right:235px;}
#content{left:235px;right:0px}

This will set up a screen with the left 235 pixels devoted to the nav, and the right rest of the screen to content.

Note, however, you won't be able to scroll the whole screen at once. Though you can set it to scroll either pane individually, by applying overflow:auto to either div.

Note also: fixed positioning is not supported in IE6 or earlier.

$(window).scrollTop() vs. $(document).scrollTop()

I've just had some of the similar problems with scrollTop described here.

In the end I got around this on Firefox and IE by using the selector $('*').scrollTop(0);

Not perfect if you have elements you don't want to effect but it gets around the Document, Body, HTML and Window disparity. If it helps...

How to use an existing database with an Android application

If you are having pre built data base than copy it in asset folder and create an new class as DataBaseHelper which implements SQLiteOpenHelper Than use following code:

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DataBaseHelperClass extends SQLiteOpenHelper{
 //The Android's default system path of your application database.
private static String DB_PATH = "/data/data/package_name/databases/";
// Data Base Name.
private static final String DATABASE_NAME = "DBName.sqlite";
// Data Base Version.
private static final int DATABASE_VERSION = 1;
// Table Names of Data Base.
static final String TABLE_Name = "tableName";

public Context context;
static SQLiteDatabase sqliteDataBase;

/**
 * Constructor
 * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
 * @param context
 * Parameters of super() are    1. Context
 *                              2. Data Base Name.
 *                              3. Cursor Factory.
 *                              4. Data Base Version.
 */
public DataBaseHelperClass(Context context) {       
    super(context, DATABASE_NAME, null ,DATABASE_VERSION);
    this.context = context;
}

/**
 * Creates a empty database on the system and rewrites it with your own database.
 * By calling this method and empty database will be created into the default system path
 * of your application so we are gonna be able to overwrite that database with our database.
 * */
public void createDataBase() throws IOException{
    //check if the database exists
    boolean databaseExist = checkDataBase();

    if(databaseExist){
        // Do Nothing.
    }else{
        this.getWritableDatabase();         
        copyDataBase(); 
    }// end if else dbExist
} // end createDataBase().

/**
 * Check if the database already exist to avoid re-copying the file each time you open the application.
 * @return true if it exists, false if it doesn't
 */
public boolean checkDataBase(){
    File databaseFile = new File(DB_PATH + DATABASE_NAME);
    return databaseFile.exists();        
}

/**
 * Copies your database from your local assets-folder to the just created empty database in the
 * system folder, from where it can be accessed and handled.
 * This is done by transferring byte stream.
 * */
private void copyDataBase() throws IOException{ 
    //Open your local db as the input stream
    InputStream myInput = context.getAssets().open(DATABASE_NAME); 
    // Path to the just created empty db
    String outFileName = DB_PATH + DATABASE_NAME; 
    //Open the empty db as the output stream
    OutputStream myOutput = new FileOutputStream(outFileName); 
    //transfer bytes from the input file to the output file
    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer))>0){
        myOutput.write(buffer, 0, length);
    }

    //Close the streams
    myOutput.flush();
    myOutput.close();
    myInput.close(); 
}

/**
 * This method opens the data base connection.
 * First it create the path up till data base of the device.
 * Then create connection with data base.
 */
public void openDataBase() throws SQLException{      
    //Open the database
    String myPath = DB_PATH + DATABASE_NAME;
    sqliteDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);  
}

/**
 * This Method is used to close the data base connection.
 */
@Override
public synchronized void close() { 
    if(sqliteDataBase != null)
        sqliteDataBase.close(); 
    super.close(); 
}

/**
* Apply your methods and class to fetch data using raw or queries on data base using 
* following demo example code as:
*/
public String getUserNameFromDB(){
    String query = "select User_First_Name From "+TABLE_USER_DETAILS;
    Cursor cursor = sqliteDataBase.rawQuery(query, null);
    String userName = null;
    if(cursor.getCount()>0){
        if(cursor.moveToFirst()){
    do{
                userName = cursor.getString(0);
            }while (cursor.moveToNext());
        }
    }
    return userName;
}


@Override
public void onCreate(SQLiteDatabase db) {
    // No need to write the create table query.
    // As we are using Pre built data base.
    // Which is ReadOnly.
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // No need to write the update table query.
    // As we are using Pre built data base.
    // Which is ReadOnly.
    // We should not update it as requirements of application.
}   
}

Hope this will help you...

In HTML5, should the main navigation be inside or outside the <header> element?

I do not like putting the nav in the header. My reasoning is:

Logic

The header contains introductory information about the document. The nav is a menu that links to other documents. To my mind this means that the content of the nav belongs to the site rather than the document. An exception would be if the NAV held forward links.

Accessibility

I like to put menus at the end of the source code rather than the start. I use CSS to send it to the top of a computer screen or leave it at the end for text-speech browsers and small screens. This avoids the need for skip-links.

Filter output in logcat by tagname

Here is how I create a tag:

private static final String TAG = SomeActivity.class.getSimpleName();
 Log.d(TAG, "some description");

You could use getCannonicalName

Here I have following TAG filters:

  • any (*) View - VERBOSE
  • any (*) Activity - VERBOSE
  • any tag starting with Xyz(*) - ERROR
  • System.out - SILENT (since I am using Log in my own code)

Here what I type in terminal:

$  adb logcat *View:V *Activity:V Xyz*:E System.out:S

How do I rename a MySQL schema?

If you're on the Model Overview page you get a tab with the schema. If you rightclick on that tab you get an option to "edit schema". From there you can rename the schema by adding a new name, then click outside the field. This goes for MySQL Workbench 5.2.30 CE

Edit: On the model overview it's under Physical Schemata

Screenshot:

enter image description here

Get Time from Getdate()

To get the format you want:

SELECT (substring(CONVERT(VARCHAR,GETDATE(),22),10,8) + ' ' + SUBSTRING(CONVERT(VARCHAR,getdate(),22), 19,2))

Why are you pulling this from sql?

How to calculate a Mod b in Casio fx-991ES calculator

Calculate x/y (your actual numbers here), and press a b/c key, which is 3rd one below Shift key.

How can I get a resource content from a static context?
  1. Create a subclass of Application, for instance public class App extends Application {
  2. Set the android:name attribute of your <application> tag in the AndroidManifest.xml to point to your new class, e.g. android:name=".App"
  3. In the onCreate() method of your app instance, save your context (e.g. this) to a static field named mContext and create a static method that returns this field, e.g. getContext():

This is how it should look:

public class App extends Application{

    private static Context mContext;

    @Override
    public void onCreate() {
        super.onCreate();
        mContext = this;
    }

    public static Context getContext(){
        return mContext;
    }
}

Now you can use: App.getContext() whenever you want to get a context, and then getResources() (or App.getContext().getResources()).

in_array() and multidimensional array

This will work too.

function in_array_r($item , $array){
    return preg_match('/"'.preg_quote($item, '/').'"/i' , json_encode($array));
}

Usage:

if(in_array_r($item , $array)){
    // found!
}

Creating an index on a table variable

If Table variable has large data, then instead of table variable(@table) create temp table (#table).table variable doesn't allow to create index after insert.

 CREATE TABLE #Table(C1 int,       
  C2 NVarchar(100) , C3 varchar(100)
  UNIQUE CLUSTERED (c1) 
 );

  1. Create table with unique clustered index

  2. Insert data into Temp "#Table" table

  3. Create non clustered indexes.

     CREATE NONCLUSTERED INDEX IX1  ON #Table (C2,C3);

Is it safe to store a JWT in localStorage with ReactJS?

Localstorage is designed to be accessible by javascript, so it doesn't provide any XSS protection. As mentioned in other answers, there is a bunch of possible ways to do an XSS attack, from which localstorage is not protected by default.

However, cookies have security flags which protect from XSS and CSRF attacks. HttpOnly flag prevents client side javascript from accessing the cookie, Secure flag only allows the browser to transfer the cookie through ssl, and SameSite flag ensures that the cookie is sent only to the origin. Although I just checked and SameSite is currently supported only in Opera and Chrome, so to protect from CSRF it's better to use other strategies. For example, sending an encrypted token in another cookie with some public user data.

So cookies are a more secure choice for storing authentication data.

How to get all registered routes in Express?

express 3.x

Okay, found it myself ... it's just app.routes :-)

express 4.x

Applications - built with express()

app._router.stack

Routers - built with express.Router()

router.stack

Note: The stack includes the middleware functions too, it should be filtered to get the "routes" only.

printf a variable in C

As Shafik already wrote you need to use the right format because scanf gets you a char. Don't hesitate to look here if u aren't sure about the usage: http://www.cplusplus.com/reference/cstdio/printf/

Hint: It's faster/nicer to write x=x+1; the shorter way: x++;

Sorry for answering what's answered just wanted to give him the link - the site was really useful to me all the time dealing with C.

PHP read and write JSON from file

Try using second parameter for json_decode function:

$json = json_decode(file_get_contents($file), true);

PHP array value passes to next row

Change the checkboxes so that the name includes the index inside the brackets:

<input type="checkbox" class="checkbox_veh" id="checkbox_addveh<?php echo $i; ?>" <?php if ($vehicle_feature[$i]->check) echo "checked"; ?> name="feature[<?php echo $i; ?>]" value="<?php echo $vehicle_feature[$i]->id; ?>">

The checkboxes that aren't checked are never submitted. The boxes that are checked get submitted, but they get numbered consecutively from 0, and won't have the same indexes as the other corresponding input fields.

Get hostname of current request in node.js Express

First of all, before providing an answer I would like to be upfront about the fact that by trusting headers you are opening the door to security vulnerabilities such as phishing. So for redirection purposes, don't use values from headers without first validating the URL is authorized.

Then, your operating system hostname might not necessarily match the DNS one. In fact, one IP might have more than one DNS name. So for HTTP purposes there is no guarantee that the hostname assigned to your machine in your operating system configuration is useable.

The best choice I can think of is to obtain your HTTP listener public IP and resolve its name via DNS. See the dns.reverse method for more info. But then, again, note that an IP might have multiple names associated with it.

INSTALL_FAILED_DUPLICATE_PERMISSION... C2D_MESSAGE

replace below lines:

<permission android:name="com.myapp.permission.C2D_MESSAGE" android:protectionLevel="signature" />
<uses-permission android:name="com.myapp.permission.C2D_MESSAGE" 
android:protectionLevel="signature" />

Export HTML page to PDF on user click using JavaScript

This is because you define your "doc" variable outside of your click event. The first time you click the button the doc variable contains a new jsPDF object. But when you click for a second time, this variable can't be used in the same way anymore. As it is already defined and used the previous time.

change it to:

$(function () {

    var specialElementHandlers = {
        '#editor': function (element,renderer) {
            return true;
        }
    };
 $('#cmd').click(function () {
        var doc = new jsPDF();
        doc.fromHTML(
            $('#target').html(), 15, 15, 
            { 'width': 170, 'elementHandlers': specialElementHandlers }, 
            function(){ doc.save('sample-file.pdf'); }
        );

    });  
});

and it will work.

What is wrong with this code that uses the mysql extension to fetch data from a database in PHP?

Your syntax is wrong... The correct coding is:

 <?php
mysql_connect("localhost","root","");
mysql_select_db("form1");
$query = mysql_query("SELECT * FROM users WHERE name = 'Admin' ");
while($rows = mysql_fetch_array($query))
{

   $rows = $rows['Name'];
   $address = $rows['Address'];
   $email = $rows['Email'];
   $subject = $rows['Subject'];
   $comment = $rows['Comment']
   echo $rows.'</br>'.$address.'</br>'.$email.'</br>'.$subject.'</br>'.$comment;
}
   ?>

const to Non-const Conversion in C++

Leaving this here for myself,

If I get this error, I probably used const char* when I should be using char* const.

This makes the pointer constant, and not the contents of the string.

const char* const makes it so the value and the pointer is constant also.

Fitting a histogram with python

Here is an example that uses scipy.optimize to fit a non-linear functions like a Gaussian, even when the data is in a histogram that isn't well ranged, so that a simple mean estimate would fail. An offset constant also would cause simple normal statistics to fail ( just remove p[3] and c[3] for plain gaussian data).

from pylab import *
from numpy import loadtxt
from scipy.optimize import leastsq

fitfunc  = lambda p, x: p[0]*exp(-0.5*((x-p[1])/p[2])**2)+p[3]
errfunc  = lambda p, x, y: (y - fitfunc(p, x))

filename = "gaussdata.csv"
data     = loadtxt(filename,skiprows=1,delimiter=',')
xdata    = data[:,0]
ydata    = data[:,1]

init  = [1.0, 0.5, 0.5, 0.5]

out   = leastsq( errfunc, init, args=(xdata, ydata))
c = out[0]

print "A exp[-0.5((x-mu)/sigma)^2] + k "
print "Parent Coefficients:"
print "1.000, 0.200, 0.300, 0.625"
print "Fit Coefficients:"
print c[0],c[1],abs(c[2]),c[3]

plot(xdata, fitfunc(c, xdata))
plot(xdata, ydata)

title(r'$A = %.3f\  \mu = %.3f\  \sigma = %.3f\ k = %.3f $' %(c[0],c[1],abs(c[2]),c[3]));

show()

Output:

A exp[-0.5((x-mu)/sigma)^2] + k 
Parent Coefficients:
1.000, 0.200, 0.300, 0.625
Fit Coefficients:
0.961231625289 0.197254597618 0.293989275502 0.65370344131

gaussian plot with fit

Default instance name of SQL Server Express

You're right, it's localhost\SQLEXPRESS (just no $) and yes, it's the same for both 2005 and 2008 express versions.

Using the rJava package on Win7 64 bit with R

I think this is an update. I was unable to install rJava (on Windows) until I installed the JDK, as per Javac is not found and javac not working in windows command prompt. The message I was getting was

'javac' is not recognized as an internal or external command, operable program or batch file.

The JDK includes the JRE, and according to https://cran.r-project.org/web/packages/rJava/index.html the current version (0.9-7 published 2015-Jul-29) of rJava

SystemRequirements:     Java JDK 1.2 or higher (for JRI/REngine JDK 1.4 or higher), GNU make

So there you are: if rJava won't install because it can't find javac, and you have the JRE installed, then try the JDK. Also, make sure that JAVA_HOME points to the JDK and not the JRE.

Environ Function code samples for VBA

Environ() gets you the value of any environment variable. These can be found by doing the following command in the Command Prompt:

set

If you wanted to get the username, you would do: 

Environ("username")

If you wanted to get the fully qualified name, you would do:

Environ("userdomain") & "\" & Environ("username")

References

How to apply a CSS filter to a background image

You need to re-structure your HTML in order to do this. You have to blur the whole element in order to blur the background. So if you want to blur only the background, it has to be its own element.

Transition of background-color

As far as I know, transitions currently work in Safari, Chrome, Firefox, Opera and Internet Explorer 10+.

This should produce a fade effect for you in these browsers:

_x000D_
_x000D_ 
a {_x000D_
    background-color: #FF0;_x000D_
}_x000D_
_x000D_
a:hover {_x000D_
    background-color: #AD310B;_x000D_
    -webkit-transition: background-color 1000ms linear;_x000D_
    -ms-transition: background-color 1000ms linear;_x000D_
    transition: background-color 1000ms linear;_x000D_
}
_x000D_ 
<a>Navigation Link</a>
_x000D_
_x000D_
_x000D_

Note: As pointed out by Gerald in the comments, if you put the transition on the a, instead of on a:hover it will fade back to the original color when your mouse moves away from the link.

This might come in handy, too: CSS Fundamentals: CSS 3 Transitions

Regex to match any character including new lines

If you don't want add the /s regex modifier (perhaps you still want . to retain its original meaning elsewhere in the regex), you may also use a character class. One possibility:

[\S\s]

a character which is not a space or is a space. In other words, any character.

You can also change modifiers locally in a small part of the regex, like so:

(?s:.)

How to install Cmake C compiler and CXX compiler

The approach I use is to start the "Visual Studio Command Prompt" which can be found in the Start menu. E.g. my visual studio 2010 Express install has a shortcute Visual Studio Command Prompt (2010) at Start Menu\Programs\Microsoft Visual Studio 2010\Visual Studio Tools.

This shortcut prepares an environment by calling a script vcvarsall.bat where the compiler, linker, etc. are setup from the right Visual Studio installation.

Alternatively, if you already have a prompt open, you can prepare the environment by calling a similar script: 

:: For x86 (using the VS100COMNTOOLS env-var)
call "%VS100COMNTOOLS%"\..\..\VC\bin\vcvars32.bat

or 

:: For amd64 (using the full path)
call C:\Program Files\Microsoft Visual Studio 10.0\VC\bin\amd64\vcvars64.bat

However:

Your output (with the '$' prompt) suggests that you are attempting to run CMake from a MSys shell. In that case it might be better to run CMake for MSys or MinGW, by explicitly specifying a makefile generator:

cmake -G"MSYS Makefiles"
cmake -G"MinGW Makefiles"

Run cmake --help to get a list of all possible generators.

Android saving file to external storage

Probably exception is thrown because there is no MediaCard subdir. You should check if all dirs in the path exist.

About visibility of your files: if you put file named .nomedia in your dir you are telling Android that you don't want it to scan it for media files and they will not appear in the gallery.

Open Facebook page from Android app?

Best answer I have found, it's working great.

Just go to your page on Facebook in the browser, right click, and click on "View source code", then find the page_id attribute: you have to use page_id here in this line after the last back-slash:

fb://page/pageID

For example:

Intent facebookAppIntent;
try {
    facebookAppIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("fb://page/1883727135173361"));
    startActivity(facebookAppIntent);
} catch (ActivityNotFoundException e) {
    facebookAppIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://facebook.com/CryOut-RadioTv-1883727135173361"));
    startActivity(facebookAppIntent);
}

How to convert image file data in a byte array to a Bitmap?

Just try this:

Bitmap bitmap = BitmapFactory.decodeFile("/path/images/image.jpg");
ByteArrayOutputStream blob = new ByteArrayOutputStream();
bitmap.compress(CompressFormat.PNG, 0 /* Ignored for PNGs */, blob);
byte[] bitmapdata = blob.toByteArray();

If bitmapdata is the byte array then getting Bitmap is done like this:

Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapdata, 0, bitmapdata.length);

Returns the decoded Bitmap, or null if the image could not be decoded.

How to calculate an angle from three points?

my angle demo program

Recently, I too have the same problem... In Delphi It's very similar to Objective-C.

procedure TForm1.FormPaint(Sender: TObject);
var ARect: TRect;
    AWidth, AHeight: Integer;
    ABasePoint: TPoint;
    AAngle: Extended;
begin
  FCenter := Point(Width div 2, Height div 2);
  AWidth := Width div 4;
  AHeight := Height div 4;
  ABasePoint := Point(FCenter.X+AWidth, FCenter.Y);
  ARect := Rect(Point(FCenter.X - AWidth, FCenter.Y - AHeight),
    Point(FCenter.X + AWidth, FCenter.Y + AHeight));
  AAngle := ArcTan2(ClickPoint.Y-Center.Y, ClickPoint.X-Center.X) * 180 / pi;
  AngleLabel.Caption := Format('Angle is %5.2f', [AAngle]);
  Canvas.Ellipse(ARect);
  Canvas.MoveTo(FCenter.X, FCenter.Y);
  Canvas.LineTo(FClickPoint.X, FClickPoint.Y);
  Canvas.MoveTo(FCenter.X, FCenter.Y);
  Canvas.LineTo(ABasePoint.X, ABasePoint.Y);
end;

syntax for creating a dictionary into another dictionary in python

You can declare a dictionary inside a dictionary by nesting the {} containers:

d = {'dict1': {'foo': 1, 'bar': 2}, 'dict2': {'baz': 3, 'quux': 4}}

And then you can access the elements using the [] syntax:

print d['dict1']           # {'foo': 1, 'bar': 2}
print d['dict1']['foo']    # 1
print d['dict2']['quux']   # 4

Given the above, if you want to add another dictionary to the dictionary, it can be done like so:

d['dict3'] = {'spam': 5, 'ham': 6}

or if you prefer to add items to the internal dictionary one by one:

d['dict4'] = {}
d['dict4']['king'] = 7
d['dict4']['queen'] = 8

Can an ASP.NET MVC controller return an Image?

You can create your own extension and do this way.

public static class ImageResultHelper
{
    public static string Image<T>(this HtmlHelper helper, Expression<Action<T>> action, int width, int height)
            where T : Controller
    {
        return ImageResultHelper.Image<T>(helper, action, width, height, "");
    }

    public static string Image<T>(this HtmlHelper helper, Expression<Action<T>> action, int width, int height, string alt)
            where T : Controller
    {
        var expression = action.Body as MethodCallExpression;
        string actionMethodName = string.Empty;
        if (expression != null)
        {
            actionMethodName = expression.Method.Name;
        }
        string url = new UrlHelper(helper.ViewContext.RequestContext, helper.RouteCollection).Action(actionMethodName, typeof(T).Name.Remove(typeof(T).Name.IndexOf("Controller"))).ToString();         
        //string url = LinkBuilder.BuildUrlFromExpression<T>(helper.ViewContext.RequestContext, helper.RouteCollection, action);
        return string.Format("<img src=\"{0}\" width=\"{1}\" height=\"{2}\" alt=\"{3}\" />", url, width, height, alt);
    }
}

public class ImageResult : ActionResult
{
    public ImageResult() { }

    public Image Image { get; set; }
    public ImageFormat ImageFormat { get; set; }

    public override void ExecuteResult(ControllerContext context)
    {
        // verify properties 
        if (Image == null)
        {
            throw new ArgumentNullException("Image");
        }
        if (ImageFormat == null)
        {
            throw new ArgumentNullException("ImageFormat");
        }

        // output 
        context.HttpContext.Response.Clear();
        context.HttpContext.Response.ContentType = GetMimeType(ImageFormat);
        Image.Save(context.HttpContext.Response.OutputStream, ImageFormat);
    }

    private static string GetMimeType(ImageFormat imageFormat)
    {
        ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
        return codecs.First(codec => codec.FormatID == imageFormat.Guid).MimeType;
    }
}
public ActionResult Index()
    {
  return new ImageResult { Image = image, ImageFormat = ImageFormat.Jpeg };
    }
    <%=Html.Image<CapchaController>(c => c.Index(), 120, 30, "Current time")%>

add column to mysql table if it does not exist

If you are running this in a script, you'll want to add the following line afterwards to make it rerunnable, otherwise you get a procedure already exists error. 

drop procedure foo;

Check whether user has a Chrome extension installed

Another possible solution if you own the website is to use inline installation. 

if (chrome.app.isInstalled) {
  // extension is installed.
}

I know this an old question but this way was introduced in Chrome 15 and so I thought Id list it for anyone only now looking for an answer.

jQuery selector to get form by name

$('form[name="frmSave"]') is correct. You mentioned you thought this would get all children with the name frmsave inside the form; this would only happen if there was a space or other combinator between the form and the selector, eg: $('form [name="frmSave"]');

$('form[name="frmSave"]') literally means find all forms with the name frmSave, because there is no combinator involved.

MySQL CURRENT_TIMESTAMP on create and on update

Guess this is a old post but actually i guess mysql supports 2 TIMESTAMP in its recent editions mysql 5.6.25 thats what im using as of now.

cURL equivalent in Node.js?

well if you really need a curl equivalent you can try node-curl 

npm install node-curl

you will probably need to add libcurl4-gnutls-dev.

How to check if a string is null in python

Try this:

if cookie and not cookie.isspace():
    # the string is non-empty
else:
    # the string is empty

The above takes in consideration the cases where the string is None or a sequence of white spaces.

How do I center a Bootstrap div with a 'spanX' class?

If anyone wants the true solution for centering BOTH images and text within a span using bootstrap row-fluid, here it is (how to implement this and explanation follows my example):

css

div.row-fluid [class*="span"] .center-in-span { 
   float: none; 
   margin: 0 auto; 
   text-align: center; 
   display: block; 
   width: auto; 
   height: auto;
}

html

<div class="row-fluid">
   <div class="span12">
      <img class="center-in-span" alt="MyExample" src="/path/to/example.jpg"/>
   </div>
</div>

<div class="row-fluid">
   <div class="span12">
      <p class="center-in-span">this is text</p>
   </div>
</div>

USAGE: To use this css to center an image within a span, simply apply the .center-in-span class to the img element, as shown above.

To use this css to center text within a span, simply apply the .center-in-span class to the p element, as shown above.

EXPLANATION: This css works because we are overriding specific bootstrap styling. The notable differences from the other answers that were posted are that the width and height are set to auto, so you don't have to used a fixed with (good for a dynamic webpage). also, the combination of setting the margin to auto, text-align:center and display:block, takes care of both images and paragraphs.

Let me know if this is thorough enough for easy implementation.

Disable automatic sorting on the first column when using jQuery DataTables

 
var table;

$(document).ready(function() {

    //datatables
    table = $('#userTable').DataTable({ 

        "processing": true, //Feature control the processing indicator.
        "serverSide": true, //Feature control DataTables' server-side processing mode.
        "order": [], //Initial no order.
         "aaSorting": [],
        // Load data for the table's content from an Ajax source
        "ajax": {
            "url": "<?php echo base_url().'admin/ajax_list';?>",
            "type": "POST"
        },

        //Set column definition initialisation properties.
        "columnDefs": [
        { 
            "targets": [ ], //first column / numbering column
            "orderable": false, //set not orderable
        },
        ],

    });

});

set 

"targets": [0]

to

 "targets": [ ]

How to compare dates in Java?

Update for Java 8 and later

These methods exists in LocalDate, LocalTime, and LocalDateTime classes.

Those classes are built into Java 8 and later. Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport and further adapted to Android in ThreeTenABP (see How to use…).

How to get a variable type in Typescript?

For : 

abc:number|string;

Use the JavaScript operator typeof: 

if (typeof abc === "number") {
    // do something
}

TypeScript understands typeof

This is called a typeguard.

More

For classes you would use instanceof e.g.

class Foo {}
class Bar {} 

// Later
if (fooOrBar instanceof Foo){
  // TypeScript now knows that `fooOrBar` is `Foo`
}

There are also other type guards e.g. in etc https://basarat.gitbooks.io/typescript/content/docs/types/typeGuard.html

Summarizing multiple columns with dplyr?

All the examples are great, but I figure I'd add one more to show how working in a "tidy" format simplifies things. Right now the data frame is in "wide" format meaning the variables "a" through "d" are represented in columns. To get to a "tidy" (or long) format, you can use gather() from the tidyr package which shifts the variables in columns "a" through "d" into rows. Then you use the group_by() and summarize() functions to get the mean of each group. If you want to present the data in a wide format, just tack on an additional call to the spread() function. 


library(tidyverse)

# Create reproducible df
set.seed(101)
df <- tibble(a   = sample(1:5, 10, replace=T), 
             b   = sample(1:5, 10, replace=T), 
             c   = sample(1:5, 10, replace=T), 
             d   = sample(1:5, 10, replace=T), 
             grp = sample(1:3, 10, replace=T))

# Convert to tidy format using gather
df %>%
    gather(key = variable, value = value, a:d) %>%
    group_by(grp, variable) %>%
    summarize(mean = mean(value)) %>%
    spread(variable, mean)
#> Source: local data frame [3 x 5]
#> Groups: grp [3]
#> 
#>     grp        a     b        c        d
#> * <int>    <dbl> <dbl>    <dbl>    <dbl>
#> 1     1 3.000000   3.5 3.250000 3.250000
#> 2     2 1.666667   4.0 4.666667 2.666667
#> 3     3 3.333333   3.0 2.333333 2.333333

SwiftUI - How do I change the background color of a View?

You can Simply Change Background Color of a View:

var body : some View{


    VStack{

        Color.blue.edgesIgnoringSafeArea(.all)

    }


}

and You can also use ZStack :

var body : some View{


    ZStack{

        Color.blue.edgesIgnoringSafeArea(.all)

    }


}

Cache busting via params

The param ?v=1.123 indicates a query string, and the browser will therefore think it is a new path from, say, ?v=1.0. Thus causing it to load from file, not from cache. As you want.

And, the browser will assume that the source will stay the same next time you call ?v=1.123 and should cache it with that string. So it will remain cached, however your server is set up, until you move to ?v=1.124 or so on.

Cannot create cache directory .. or directory is not writable. Proceeding without cache in Laravel

When you installed composer pretty sure you used $ sudo command because of that the ~/.composer folder was created by the root.

Run this to fix the issue:

$ sudo chown -R $USER $HOME/.composer

deleting folder from java

You should delete the file in the folder first , then the folder.This way you will recursively call the method.

What is REST? Slightly confused

http://en.wikipedia.org/wiki/Representational_State_Transfer

The basic idea is that instead of having an ongoing connection to the server, you make a request, get some data, show that to a user, but maybe not all of it, and then when the user does something which calls for more data, or to pass some up to the server, the client initiates a change to a new state.

Error:Cause: unable to find valid certification path to requested target

Switching to the smartphone network & disabling the web security tool installed on my computer solved the problem.

What's the difference between subprocess Popen and call (how can I use them)?

There are two ways to do the redirect. Both apply to either subprocess.Popen or subprocess.call.

  1. Set the keyword argument shell = True or executable = /path/to/the/shell and specify the command just as you have it there.

  2. Since you're just redirecting the output to a file, set the keyword argument

    stdout = an_open_writeable_file_object

    where the object points to the output file.

subprocess.Popen is more general than subprocess.call.

Popen doesn't block, allowing you to interact with the process while it's running, or continue with other things in your Python program. The call to Popen returns a Popen object.

call does block. While it supports all the same arguments as the Popen constructor, so you can still set the process' output, environmental variables, etc., your script waits for the program to complete, and call returns a code representing the process' exit status. 

returncode = call(*args, **kwargs)

is basically the same as calling 

returncode = Popen(*args, **kwargs).wait()

call is just a convenience function. It's implementation in CPython is in subprocess.py:

def call(*popenargs, timeout=None, **kwargs):
    """Run command with arguments.  Wait for command to complete or
    timeout, then return the returncode attribute.

    The arguments are the same as for the Popen constructor.  Example:

    retcode = call(["ls", "-l"])
    """
    with Popen(*popenargs, **kwargs) as p:
        try:
            return p.wait(timeout=timeout)
        except:
            p.kill()
            p.wait()
            raise

As you can see, it's a thin wrapper around Popen.

React: trigger onChange if input value is changing by state?

You need to trigger the onChange event manually. On text inputs onChange listens for input events.

So in you handleClick function you need to trigger event like 

handleClick () {
    this.setState({value: 'another random text'})
    var event = new Event('input', { bubbles: true });
    this.myinput.dispatchEvent(event);
  }

Complete code

class App extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
    value: 'random text'
    }
  }
  handleChange (e) {
    console.log('handle change called')
  }
  handleClick () {
    this.setState({value: 'another random text'})
    var event = new Event('input', { bubbles: true });
    this.myinput.dispatchEvent(event);
  }
  render () {
    return (
      <div>
        <input readOnly value={this.state.value} onChange={(e) => {this.handleChange(e)}} ref={(input)=> this.myinput = input}/>
        <button onClick={this.handleClick.bind(this)}>Change Input</button>
      </div>
    )
  }
}

ReactDOM.render(<App />,  document.getElementById('app'))

Codepen

Edit: As Suggested by @Samuel in the comments, a simpler way would be to call handleChange from handleClick if you don't need to the event object in handleChange like

handleClick () {
    this.setState({value: 'another random text'})
    this.handleChange();
  }

I hope this is what you need and it helps you.

How to uninstall Ruby from /usr/local?

It's not a good idea to uninstall 1.8.6 if it's in /usr/bin. That is owned by the OS and is expected to be there.

If you put /usr/local/bin in your PATH before /usr/bin then things you have installed in /usr/local/bin will be found before any with the same name in /usr/bin, effectively overwriting or updating them, without actually doing so. You can still reach them by explicitly using /usr/bin in your #! interpreter invocation line at the top of your code.

@Anurag recommended using RVM, which I'll second. I use it to manage 1.8.7 and 1.9.1 in addition to the OS's 1.8.6.

How to build & install GLFW 3 and use it in a Linux project

I solved it in this way

A pkg-config file describes all necessary compile-time and link-time flags and dependencies needed to use a library. 

pkg-config --static --libs glfw3

shows me that

-L/usr/local/lib -lglfw3 -lrt -lXrandr -lXinerama -lXi -lXcursor -lGL -lm -ldl -lXrender -ldrm -lXdamage -lX11-xcb -lxcb-glx -lxcb-dri2 -lxcb-dri3 -lxcb-present -lxcb-sync -lxshmfence -lXxf86vm -lXfixes -lXext -lX11 -lpthread -lxcb -lXau -lXdmcp

I don't know if all these libs are actually necessary for compiling but for me it works...

Forward X11 failed: Network error: Connection refused

you should install a x server such as XMing. and keep the x server is running. config your putty like this :Connection-Data-SSH-X11-Enable X11 forwarding should be checked. and X display location : localhost:0

In Python, how do I use urllib to see if a website is 404 or 200?

You can use urllib2 as well:

import urllib2

req = urllib2.Request('http://www.python.org/fish.html')
try:
    resp = urllib2.urlopen(req)
except urllib2.HTTPError as e:
    if e.code == 404:
        # do something...
    else:
        # ...
except urllib2.URLError as e:
    # Not an HTTP-specific error (e.g. connection refused)
    # ...
else:
    # 200
    body = resp.read()

Note that HTTPError is a subclass of URLError which stores the HTTP status code.

Get a list of URLs from a site

The best on I have found is http://www.auditmypc.com/xml-sitemap.asp which uses Java, and has no limit on pages, and even lets you export results as a raw URL list.

It also uses sessions, so if you are using a CMS, make sure you are logged out before you run the crawl.

Typing Greek letters etc. in Python plots

You need to make the strings raw and use latex:

fig.gca().set_ylabel(r'$\lambda$')

As of matplotlib 2.0 the default font supports most western alphabets and can simple do

ax.set_xlabel('?')

with unicode.

Proper way to rename solution (and directories) in Visual Studio

If you have problems with loading Shared projects, like Xamarin, remember to change reference to shared libs in csproj files. I developed a CocosSharp game and Droid/iOS/WP81 projects didn't want to load. I had to change the line below in every csproj file (Driod/iOS/WP81) which referenced Shared lib. That was caused because of folder names change, so replace YOUR_PREVIOUS_NAMESPACE with your new names of folders.

<Import Project="..\YOUR_PREVIOUS_NAMESPACE.Shared\EmptyProject.Shared.projitems" Label="Shared" />

Also, I noticed that for .Driod projects, assembly name in project properties cannot be changed using Visual Studio (I use 2015). I had to change assembly name manually in the .Droid.csproj file.

<AssemblyName>YourNameSpace</AssemblyName>

Then I loaded solution and in project properties view new name appeared. After rebuilding dll with that name was generated.

Calling filter returns <filter object at ... >

It looks like you're using python 3.x. In python3, filter, map, zip, etc return an object which is iterable, but not a list. In other words,

filter(func,data) #python 2.x

is equivalent to:

list(filter(func,data)) #python 3.x

I think it was changed because you (often) want to do the filtering in a lazy sense -- You don't need to consume all of the memory to create a list up front, as long as the iterator returns the same thing a list would during iteration.

If you're familiar with list comprehensions and generator expressions, the above filter is now (almost) equivalent to the following in python3.x:

( x for x in data if func(x) )

As opposed to:

[ x for x in data if func(x) ]

in python 2.x

How do I add a reference to the MySQL connector for .NET?

This is an older question, but I found it yesterday while struggling with getting the MySQL Connector reference working properly on examples I'd found on the web. I'm working with VS 2010 on Win7 64 bit but have to work with .NET 3.5.

As others have stated, you need to download the .Net & Mono versions (I don't know why this is true, but it's what I've found works). The link to the connectors is given above in the earlier answers.

  • Extract the connectors somewhere convenient.
  • Open the project in Visual Studio, then on the menu bar navigate to Solution Explorer (View > Solution Explorer), and choose Properties (first box on the far left of the toolbar. The Solution Explorer shows up in the top right pane for me, but YMMV).
  • In Properties, select References & locate the instance for mysql.data. It's likely to have a yellow bang on it (Yellow triangle with exclamation point in it). Remove it.
  • Then on the menu bar, navigate to Project > Add Reference... > Browse > point to where you downloaded the connectors. I have only been able to get the V2 version to work, but that may be a factor of my platform, not sure.
  • Clean & build your application. You should now be able to use the MySQL connectors to talk to your database.
  • You can also now downgrade your .NET instance if you need to (we're constrained to .NET 3.5, but mysql.data.dll wants 4.0 at the time of my writing this). On the menu bar, navigate to the properties of your project (Project > Properties). Choose the Application tab > Target framework > Choose which .NET framework you want to use. You have to build the application at least once before you can change the .NET framework. Once you built once the connector will no longer complain about the lower version of .NET.

Fastest Way of Inserting in Entity Framework

All the solutions written here don't help because when you do SaveChanges(), insert statements are sent to database one by one, that's how Entity works.

And if your trip to database and back is 50 ms for instance then time needed for insert is number of records x 50 ms.

You have to use BulkInsert, here is the link: https://efbulkinsert.codeplex.com/

I got insert time reduced from 5-6 minutes to 10-12 seconds by using it.

Calculate days between two Dates in Java 8

Get number of days before Christmas from current day , try this

System.out.println(ChronoUnit.DAYS.between(LocalDate.now(),LocalDate.of(Year.now().getValue(), Month.DECEMBER, 25)));

Passing javascript variable to html textbox

 
document.getElementById("txtBillingGroupName").value = groupName;

How to calculate an age based on a birthday?

I do it like this:

(Shortened the code a bit)

public struct Age
{
    public readonly int Years;
    public readonly int Months;
    public readonly int Days;

}

public Age( int y, int m, int d ) : this()
{
    Years = y;
    Months = m;
    Days = d;
}

public static Age CalculateAge ( DateTime birthDate, DateTime anotherDate )
{
    if( startDate.Date > endDate.Date )
        {
            throw new ArgumentException ("startDate cannot be higher then endDate", "startDate");
        }

        int years = endDate.Year - startDate.Year;
        int months = 0;
        int days = 0;

        // Check if the last year, was a full year.
        if( endDate < startDate.AddYears (years) && years != 0 )
        {
            years--;
        }

        // Calculate the number of months.
        startDate = startDate.AddYears (years);

        if( startDate.Year == endDate.Year )
        {
            months = endDate.Month - startDate.Month;
        }
        else
        {
            months = ( 12 - startDate.Month ) + endDate.Month;
        }

        // Check if last month was a complete month.
        if( endDate < startDate.AddMonths (months) && months != 0 )
        {
            months--;
        }

        // Calculate the number of days.
        startDate = startDate.AddMonths (months);

        days = ( endDate - startDate ).Days;

        return new Age (years, months, days);
}

// Implement Equals, GetHashCode, etc... as well
// Overload equality and other operators, etc...

}

Encrypt & Decrypt using PyCrypto AES 256

https://stackoverflow.com/a/21928790/11402877

compatible utf-8 encoding

def _pad(self, s):
    s = s.encode()
    res = s + (self.bs - len(s) % self.bs) * chr(self.bs - len(s) % self.bs).encode()
    return res

Comparing chars in Java

If you have specific chars should be:

Collection<Character> specificChars = Arrays.asList('A', 'D', 'E');  // more chars
char symbol = 'Y';
System.out.println(specificChars.contains(symbol));   // false
symbol = 'A';
System.out.println(specificChars.contains(symbol));   // true

How to set auto increment primary key in PostgreSQL?

If you want to do this in pgadmin, it is much easier. It seems in postgressql, to add a auto increment to a column, we first need to create a auto increment sequence and add it to the required column. I did like this.

1) Firstly you need to make sure there is a primary key for your table. Also keep the data type of the primary key in bigint or smallint. (I used bigint, could not find a datatype called serial as mentioned in other answers elsewhere)

2)Then add a sequence by right clicking on sequence-> add new sequence. If there is no data in the table, leave the sequence as it is, don't make any changes. Just save it. If there is existing data, add the last or highest value in the primary key column to the Current value in Definitions tab as shown below. enter image description here

3)Finally, add the line nextval('your_sequence_name'::regclass) to the Default value in your primary key as shown below.

enter image description here Make sure the sequence name is correct here. This is all and auto increment should work.

How to add conditional attribute in Angular 2?

You can use a better approach for someone writing HTML for an already existing scss.
html

[attr.role]="<boolean>"

scss

[role = "true"] { ... }

That way you don't need to <boolean> ? true : null every time.

Rebuild Docker container on file changes

You can run build for a specific service by running docker-compose up --build <service name> where the service name must match how did you call it in your docker-compose file.

Example Let's assume that your docker-compose file contains many services (.net app - database - let's encrypt... etc) and you want to update only the .net app which named as application in docker-compose file. You can then simply run docker-compose up --build application

Extra parameters In case you want to add extra parameters to your command such as -d for running in the background, the parameter must be before the service name: docker-compose up --build -d application

Difference between exit() and sys.exit() in Python

exit is a helper for the interactive shell - sys.exit is intended for use in programs.

The site module (which is imported automatically during startup, except if the -S command-line option is given) adds several constants to the built-in namespace (e.g. exit). They are useful for the interactive interpreter shell and should not be used in programs.

Technically, they do mostly the same: raising SystemExit. sys.exit does so in sysmodule.c:

static PyObject *
sys_exit(PyObject *self, PyObject *args)
{
    PyObject *exit_code = 0;
    if (!PyArg_UnpackTuple(args, "exit", 0, 1, &exit_code))
        return NULL;
    /* Raise SystemExit so callers may catch it or clean up. */
    PyErr_SetObject(PyExc_SystemExit, exit_code);
   return NULL;
}

While exit is defined in site.py and _sitebuiltins.py, respectively.

class Quitter(object):
    def __init__(self, name):
        self.name = name
    def __repr__(self):
        return 'Use %s() or %s to exit' % (self.name, eof)
    def __call__(self, code=None):
        # Shells like IDLE catch the SystemExit, but listen when their
        # stdin wrapper is closed.
        try:
            sys.stdin.close()
        except:
            pass
        raise SystemExit(code)
__builtin__.quit = Quitter('quit')
__builtin__.exit = Quitter('exit')

Note that there is a third exit option, namely os._exit, which exits without calling cleanup handlers, flushing stdio buffers, etc. (and which should normally only be used in the child process after a fork()).

C linked list inserting node at the end

This works fine:

struct node *addNode(node *head, int value) {
    node *newNode = (node *) malloc(sizeof(node));
    newNode->value = value;
    newNode->next = NULL;

    if (head == NULL) {
        // Add at the beginning
        head = newNode;
    } else {
        node *current = head;

        while (current->next != NULL) {
            current = current->next;
        };

        // Add at the end
        current->next = newNode;
    }

    return head;
}

Example usage:

struct node *head = NULL;

for (int currentIndex = 1; currentIndex < 10; currentIndex++) {
    head = addNode(head, currentIndex);
}

Why does javascript replace only first instance when using replace?

Unlike the C#/.NET class library (and most other sensible languages), when you pass a String in as the string-to-match argument to the string.replace method, it doesn't do a string replace. It converts the string to a RegExp and does a regex substitution. As Gumbo explains, a regex substitution requires the g?lobal flag, which is not on by default, to replace all matches in one go.

If you want a real string-based replace — for example because the match-string is dynamic and might contain characters that have a special meaning in regexen — the JavaScript idiom for that is:

var id= 'c_'+date.split('/').join('');

Missing styles. Is the correct theme chosen for this layout?

This is because you select not a theme of your project. Try to do next:

enter image description here

Curl not recognized as an internal or external command, operable program or batch file

Steps to install curl in windows

Install cURL on Windows

There are 4 steps to follow to get cURL installed on Windows.

Step 1 and Step 2 is to install SSL library. Step 3 is to install cURL. Step 4 is to install a recent certificate

Step One: Install Visual C++ 2008 Redistributables

From https://www.microsoft.com/en-za/download/details.aspx?id=29 For 64bit systems Visual C++ 2008 Redistributables (x64) For 32bit systems Visual C++ 2008 Redistributables (x32)

Step Two: Install Win(32/64) OpenSSL v1.0.0k Light

From http://www.shininglightpro.com/products/Win32OpenSSL.html For 64bit systems Win64 OpenSSL v1.0.0k Light For 32bit systems Win32 OpenSSL v1.0.0k Light

Step Three: Install cURL

Depending on if your system is 32 or 64 bit, download the corresponding** curl.exe.** For example, go to the Win64 - Generic section and download the Win64 binary with SSL support (the one where SSL is not crossed out). Visit http://curl.haxx.se/download.html

Copy curl.exe to C:\Windows\System32

Step Four: Install Recent Certificates

Do not skip this step. Download a recent copy of valid CERT files from https://curl.haxx.se/ca/cacert.pem Copy it to the same folder as you placed curl.exe (C:\Windows\System32) and rename it as curl-ca-bundle.crt

If you have already installed curl or after doing the above steps, add the directory where it's installed to the windows path:

1 - From the Desktop, right-click My Computer and click Properties.
2 - Click Advanced System Settings .
3 - In the System Properties window click the Environment Variables button.
4 - Select Path and click Edit.
5 - Append ;c:\path to curl directory at the end.
5 - Click OK.
6 - Close and re-open the command prompt

500 internal server error at GetResponse()

In my case my request object inherited from base object. Without knowingly I added a property with int? in my request object and my base object also has same property ( same name ) with int datatype. I noticed this and deleted the property which I added in request object and after that it worked fine.

Append value to empty vector in R?

Appending to an object in a for loop causes the entire object to be copied on every iteration, which causes a lot of people to say "R is slow", or "R loops should be avoided".

As BrodieG mentioned in the comments: it is much better to pre-allocate a vector of the desired length, then set the element values in the loop.

Here are several ways to append values to a vector. All of them are discouraged.

Appending to a vector in a loop

# one way
for (i in 1:length(values))
  vector[i] <- values[i]
# another way
for (i in 1:length(values))
  vector <- c(vector, values[i])
# yet another way?!?
for (v in values)
  vector <- c(vector, v)
# ... more ways

help("append") would have answered your question and saved the time it took you to write this question (but would have caused you to develop bad habits). ;-)

Note that vector <- c() isn't an empty vector; it's NULL. If you want an empty character vector, use vector <- character().

Pre-allocate the vector before looping

If you absolutely must use a for loop, you should pre-allocate the entire vector before the loop. This will be much faster than appending for larger vectors.

set.seed(21)
values <- sample(letters, 1e4, TRUE)
vector <- character(0)
# slow
system.time( for (i in 1:length(values)) vector[i] <- values[i] )
#   user  system elapsed 
#  0.340   0.000   0.343 
vector <- character(length(values))
# fast(er)
system.time( for (i in 1:length(values)) vector[i] <- values[i] )
#   user  system elapsed 
#  0.024   0.000   0.023

How to repair a serialized string which has been corrupted by an incorrect byte count length?

This error is caused because your charset is wrong.

Set charset after open tag: 

header('Content-Type: text/html; charset=utf-8');

And set charset utf8 in your database : 

mysql_query("SET NAMES 'utf8'");

path.join vs path.resolve with __dirname

 
const absolutePath = path.join(__dirname, some, dir);

vs.

const absolutePath = path.resolve(__dirname, some, dir);

path.join will concatenate __dirname which is the directory name of the current file concatenated with values of some and dir with platform-specific separator.

Whereas

path.resolve will process __dirname, some and dir i.e. from right to left prepending it by processing it.

If any of the values of some or dir corresponds to a root path then the previous path will be omitted and process rest by considering it as root

In order to better understand the concept let me explain both a little bit more detail as follows:-

The path.join and path.resolve are two different methods or functions of the path module provided by nodejs.

Where both accept a list of paths but the difference comes in the result i.e. how they process these paths.

path.join concatenates all given path segments together using the platform-specific separator as a delimiter, then normalizes the resulting path. While the path.resolve() process the sequence of paths from right to left, with each subsequent path prepended until an absolute path is constructed.

When no arguments supplied

The following example will help you to clearly understand both concepts:-

My filename is index.js and the current working directory is E:\MyFolder\Pjtz\node

const path = require('path');

console.log("path.join() : ", path.join());
// outputs .
console.log("path.resolve() : ", path.resolve());
// outputs current directory or equivalent to __dirname

Result

? node index.js
path.join() :  .
path.resolve() :  E:\MyFolder\Pjtz\node

path.resolve() method will output the absolute path whereas the path.join() returns . representing the current working directory if nothing is provided

When some root path is passed as arguments

const path=require('path');

console.log("path.join() : " ,path.join('abc','/bcd'));
console.log("path.resolve() : ",path.resolve('abc','/bcd'));

Result i

? node index.js
path.join() :  abc\bcd
path.resolve() :  E:\bcd

path.join() only concatenates the input list with platform-specific separator while the path.resolve() process the sequence of paths from right to left, with each subsequent path prepended until an absolute path is constructed.

Java: unparseable date exception

From Oracle docs, Date.toString() method convert Date object to a String of the specific form - do not use toString method on Date object. Try to use: 

String stringDate = new SimpleDateFormat(YOUR_STRING_PATTERN).format(yourDateObject);

Next step is parse stringDate to Date:

Date date = new SimpleDateFormat(OUTPUT_PATTERN).parse(stringDate);

Note that, parse method throws ParseException

how to set auto increment column with sql developer

I found this post, which looks a bit old, but I figured I'd update everyone on my new findings.

I am using Oracle SQL Developer 4.0.2.15 on Windows. Our database is Oracle 10g (version 10.2.0.1) running on Windows.

To make a column auto-increment in Oracle -

  1. Open up the database connection in the Connections tab
  2. Expand the Tables section, and right click the table that has the column you want to change to auto-increment, and select Edit...
  3. Choose the Columns section, and select the column you want to auto-increment (Primary Key column)
  4. Next, click the "Identity Column" section below the list of columns, and change type from None to "Column Sequence"
  5. Leave the default settings (or change the names of the sequence and trigger if you'd prefer) and then click OK

Your id column (primary key) will now auto-increment, but the sequence will be starting at 1. If you need to increment the id to a certain point, you'll have to run a few alter statements against the sequence.
This post has some more details and how to overcome this.

I found the solution here

Return JSON for ResponseEntity<String>

An alternative solution is to use a wrapper for the String, for instances this:

public class StringResponse {
    private String response;
    public StringResponse(String response) {
        this.response = response;
    }
    public String getResponse() {
        return response;
    }
}

Then return this in your controller's methods:

ResponseEntity<StringResponse>

org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15

I got similar error (org.aspectj.apache.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15) while using aspectj 1.8.13. Solution was to align all compilation into jdk 8 and being careful not to put aspectj library's (1.6.13 for instance) other versions to buildpath/classpath.

How to debug PDO database queries?

Here is a function I made to return a SQL query with "resolved" parameters.

function paramToString($query, $parameters) {
    if(!empty($parameters)) {
        foreach($parameters as $key => $value) {
            preg_match('/(\?(?!=))/i', $query, $match, PREG_OFFSET_CAPTURE);
            $query = substr_replace($query, $value, $match[0][1], 1);
        }
    }
    return $query;
    $query = "SELECT email FROM table WHERE id = ? AND username = ?";
    $values = [1, 'Super'];

    echo paramToString($query, $values);

Assuming you execute like this

$values = array(1, 'SomeUsername');
$smth->execute($values);

This function DOES NOT add quotes to queries but does the job for me.

How to 'bulk update' with Django?

Update:

Django 2.2 version now has a bulk_update.

Old answer:

Refer to the following django documentation section

Updating multiple objects at once

In short you should be able to use: 

ModelClass.objects.filter(name='bar').update(name="foo")

You can also use F objects to do things like incrementing rows:

from django.db.models import F
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)

See the documentation.

However, note that:

  • This won't use ModelClass.save method (so if you have some logic inside it won't be triggered).
  • No django signals will be emitted.
  • You can't perform an .update() on a sliced QuerySet, it must be on an original QuerySet so you'll need to lean on the .filter() and .exclude() methods.

How do I unload (reload) a Python module?

You can reload a module when it has already been imported by using the reload builtin function (Python 3.4+ only):

from importlib import reload  
import foo

while True:
    # Do some things.
    if is_changed(foo):
        foo = reload(foo)

In Python 3, reload was moved to the imp module. In 3.4, imp was deprecated in favor of importlib, and reload was added to the latter. When targeting 3 or later, either reference the appropriate module when calling reload or import it.

I think that this is what you want. Web servers like Django's development server use this so that you can see the effects of your code changes without restarting the server process itself.

To quote from the docs:

Python modules’ code is recompiled and the module-level code reexecuted, defining a new set of objects which are bound to names in the module’s dictionary. The init function of extension modules is not called a second time. As with all other objects in Python the old objects are only reclaimed after their reference counts drop to zero. The names in the module namespace are updated to point to any new or changed objects. Other references to the old objects (such as names external to the module) are not rebound to refer to the new objects and must be updated in each namespace where they occur if that is desired.

As you noted in your question, you'll have to reconstruct Foo objects if the Foo class resides in the foo module.

How to change icon on Google map marker

 
var marker = new google.maps.Marker({
                position: new google.maps.LatLng(23.016427,72.571156),
                map: map,
                icon: 'images/map_marker_icon.png',
                title: 'Hi..!'
            });

apply local path on icon only

How do you create different variable names while in a loop?

I think the challenge here is not to call upon global()

I would personally define a list for your (dynamic) variables to be held and then append to it within a for loop. Then use a separate for loop to view each entry or even execute other operations.

Here is an example - I have a number of network switches (say between 2 and 8) at various BRanches. Now I need to ensure I have a way to determining how many switches are available (or alive - ping test) at any given branch and then perform some operations on them.

Here is my code:

import requests
import sys

def switch_name(branchNum):
    # s is an empty list to start with
    s = []
    #this FOR loop is purely for creating and storing the dynamic variable names in s
    for x in range(1,8,+1):
        s.append("BR" + str(branchNum) + "SW0" + str(x))

    #this FOR loop is used to read each of the switch in list s and perform operations on
    for i in s:
        print(i,"\n")
        # other operations can be executed here too for each switch (i) - like SSH in using paramiko and changing switch interface VLAN etc.


def main():  

    # for example's sake - hard coding the site code
    branchNum= "123"
    switch_name(branchNum)


if __name__ == '__main__':
    main()

Output is:

BR123SW01

BR123SW02

BR123SW03

BR123SW04

BR123SW05

BR123SW06

BR123SW07

How to convert a table to a data frame

If you are using the tidyverse, you can use

as_data_frame(table(myvector))

to get a tibble (i.e. a data frame with some minor variations from the base class)

How to make a JFrame Modal in Swing java

just replace JFrame to JDialog in class

public class MyDialog extends JFrame // delete JFrame and write JDialog

and then write setModal(true); in constructor

After that you will be able to construct your Form in netbeans and the form becomes modal

save a pandas.Series histogram plot to file

Use the Figure.savefig() method, like so:

ax = s.hist()  # s is an instance of Series
fig = ax.get_figure()
fig.savefig('/path/to/figure.pdf')

It doesn't have to end in pdf, there are many options. Check out the documentation.

Alternatively, you can use the pyplot interface and just call the savefig as a function to save the most recently created figure:

import matplotlib.pyplot as plt
s.hist()
plt.savefig('path/to/figure.pdf')  # saves the current figure

Run a task every x-minutes with Windows Task Scheduler

After you select the minimum repeat option (5 minutes or 10 minutes) you can highlight the number and write whatever number you want

Creating a LinkedList class from scratch

Please read this article: How To Implement a LinkedList Class From Scratch In Java

package com.crunchify.tutorials;

/**
 * @author Crunchify.com
 */

public class CrunchifyLinkedListTest {

    public static void main(String[] args) {
        CrunchifyLinkedList lList = new CrunchifyLinkedList();

        // add elements to LinkedList
        lList.add("1");
        lList.add("2");
        lList.add("3");
        lList.add("4");
        lList.add("5");

        /*
         * Please note that primitive values can not be added into LinkedList
         * directly. They must be converted to their corresponding wrapper
         * class.
         */

        System.out.println("lList - print linkedlist: " + lList);
        System.out.println("lList.size() - print linkedlist size: " + lList.size());
        System.out.println("lList.get(3) - get 3rd element: " + lList.get(3));
        System.out.println("lList.remove(2) - remove 2nd element: " + lList.remove(2));
        System.out.println("lList.get(3) - get 3rd element: " + lList.get(3));
        System.out.println("lList.size() - print linkedlist size: " + lList.size());
        System.out.println("lList - print linkedlist: " + lList);
    }
}

class CrunchifyLinkedList {
    // reference to the head node.
    private Node head;
    private int listCount;

    // LinkedList constructor
    public CrunchifyLinkedList() {
        // this is an empty list, so the reference to the head node
        // is set to a new node with no data
        head = new Node(null);
        listCount = 0;
    }

    public void add(Object data)
    // appends the specified element to the end of this list.
    {
        Node crunchifyTemp = new Node(data);
        Node crunchifyCurrent = head;
        // starting at the head node, crawl to the end of the list
        while (crunchifyCurrent.getNext() != null) {
            crunchifyCurrent = crunchifyCurrent.getNext();
        }
        // the last node's "next" reference set to our new node
        crunchifyCurrent.setNext(crunchifyTemp);
        listCount++;// increment the number of elements variable
    }

    public void add(Object data, int index)
    // inserts the specified element at the specified position in this list
    {
        Node crunchifyTemp = new Node(data);
        Node crunchifyCurrent = head;
        // crawl to the requested index or the last element in the list,
        // whichever comes first
        for (int i = 1; i < index && crunchifyCurrent.getNext() != null; i++) {
            crunchifyCurrent = crunchifyCurrent.getNext();
        }
        // set the new node's next-node reference to this node's next-node
        // reference
        crunchifyTemp.setNext(crunchifyCurrent.getNext());
        // now set this node's next-node reference to the new node
        crunchifyCurrent.setNext(crunchifyTemp);
        listCount++;// increment the number of elements variable
    }

    public Object get(int index)
    // returns the element at the specified position in this list.
    {
        // index must be 1 or higher
        if (index <= 0)
            return null;

        Node crunchifyCurrent = head.getNext();
        for (int i = 1; i < index; i++) {
            if (crunchifyCurrent.getNext() == null)
                return null;

            crunchifyCurrent = crunchifyCurrent.getNext();
        }
        return crunchifyCurrent.getData();
    }

    public boolean remove(int index)
    // removes the element at the specified position in this list.
    {
        // if the index is out of range, exit
        if (index < 1 || index > size())
            return false;

        Node crunchifyCurrent = head;
        for (int i = 1; i < index; i++) {
            if (crunchifyCurrent.getNext() == null)
                return false;

            crunchifyCurrent = crunchifyCurrent.getNext();
        }
        crunchifyCurrent.setNext(crunchifyCurrent.getNext().getNext());
        listCount--; // decrement the number of elements variable
        return true;
    }

    public int size()
    // returns the number of elements in this list.
    {
        return listCount;
    }

    public String toString() {
        Node crunchifyCurrent = head.getNext();
        String output = "";
        while (crunchifyCurrent != null) {
            output += "[" + crunchifyCurrent.getData().toString() + "]";
            crunchifyCurrent = crunchifyCurrent.getNext();
        }
        return output;
    }

    private class Node {
        // reference to the next node in the chain,
        // or null if there isn't one.
        Node next;
        // data carried by this node.
        // could be of any type you need.
        Object data;

        // Node constructor
        public Node(Object dataValue) {
            next = null;
            data = dataValue;
        }

        // another Node constructor if we want to
        // specify the node to point to.
        public Node(Object dataValue, Node nextValue) {
            next = nextValue;
            data = dataValue;
        }

        // these methods should be self-explanatory
        public Object getData() {
            return data;
        }

        public void setData(Object dataValue) {
            data = dataValue;
        }

        public Node getNext() {
            return next;
        }

        public void setNext(Node nextValue) {
            next = nextValue;
        }
    }
}

Output

lList - print linkedlist: [1][2][3][4][5]
lList.size() - print linkedlist size: 5
lList.get(3) - get 3rd element: 3
lList.remove(2) - remove 2nd element: true
lList.get(3) - get 3rd element: 4
lList.size() - print linkedlist size: 4
lList - print linkedlist: [1][3][4][5]

Regex: Check if string contains at least one digit

In Java:

public boolean containsNumber(String string)
{
    return string.matches(".*\\d+.*");
}

How to print something to the console in Xcode?

How to print:

NSLog(@"Something To Print");

Or

NSString * someString = @"Something To Print";
NSLog(@"%@", someString);

For other types of variables, use:

NSLog(@"%@", someObject);
NSLog(@"%i", someInt);
NSLog(@"%f", someFloat);
/// etc...

Can you show it in phone?

Not by default, but you could set up a display to show you.

Update for Swift

print("Print this string")
print("Print this \(variable)")
print("Print this ", variable)
print(variable)

Call external javascript functions from java code

Use ScriptEngine.eval(java.io.Reader) to read the script

ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName("JavaScript");
// read script file
engine.eval(Files.newBufferedReader(Paths.get("C:/Scripts/Jsfunctions.js"), StandardCharsets.UTF_8));

Invocable inv = (Invocable) engine;
// call function from script file
inv.invokeFunction("yourFunction", "param");

String.strip() in Python

No, it is better practice to leave them out.

Without strip(), you can have empty keys and values:

apples<tab>round, fruity things
oranges<tab>round, fruity things
bananas<tab>

Without strip(), bananas is present in the dictionary but with an empty string as value. With strip(), this code will throw an exception because it strips the tab of the banana line.

How to reverse an std::string?

I'm not sure what you mean by a string that contains binary numbers. But for reversing a string (or any STL-compatible container), you can use std::reverse(). std::reverse() operates in place, so you may want to make a copy of the string first:

#include <algorithm>
#include <iostream>
#include <string>

int main()
{
    std::string foo("foo");
    std::string copy(foo);
    std::cout << foo << '\n' << copy << '\n';

    std::reverse(copy.begin(), copy.end());
    std::cout << foo << '\n' << copy << '\n';
}

can we use xpath with BeautifulSoup?

Maybe you can try the following without XPath

from simplified_scrapy.simplified_doc import SimplifiedDoc 
html = '''
<html>
<body>
<div>
    <h1>Example Domain</h1>
    <p>This domain is for use in illustrative examples in documents. You may use this
    domain in literature without prior coordination or asking for permission.</p>
    <p><a href="https://www.iana.org/domains/example">More information...</a></p>
</div>
</body>
</html>
'''
# What XPath can do, so can it
doc = SimplifiedDoc(html)
# The result is the same as doc.getElementByTag('body').getElementByTag('div').getElementByTag('h1').text
print (doc.body.div.h1.text)
print (doc.div.h1.text)
print (doc.h1.text) # Shorter paths will be faster
print (doc.div.getChildren())
print (doc.div.getChildren('p'))

QString to char* conversion

EDITED

this way also works

QString str ("Something");

char* ch = str.toStdString().C_str();

How to convert from int to string in objective c: example code

 
int val1 = [textBox1.text integerValue];
int val2 = [textBox2.text integerValue];

int resultValue = val1 * val2;

textBox3.text = [NSString stringWithFormat: @"%d", resultValue];

2D arrays in Python

 
>>> a = []

>>> for i in xrange(3):
...     a.append([])
...     for j in xrange(3):
...             a[i].append(i+j)
...
>>> a
[[0, 1, 2], [1, 2, 3], [2, 3, 4]]
>>>

How to access component methods from “outside” in ReactJS?

If you want to call functions on components from outside React, you can call them on the return value of renderComponent:

var Child = React.createClass({…});
var myChild = React.renderComponent(Child);
myChild.someMethod();

The only way to get a handle to a React Component instance outside of React is by storing the return value of React.renderComponent. Source.

Using Html.ActionLink to call action on different controller

If you grab the MVC Futures assembly (which I would highly recommend) you can then use a generic when creating the ActionLink and a lambda to construct the route:

<%=Html.ActionLink<Product>(c => c.Action( o.Value ), "Details" ) %>

You can get the futures assembly here: http://aspnet.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=24471

Serialize an object to XML

I will start with the copy answer of Ben Gripka:

public void Save(string FileName)
{
    using (var writer = new System.IO.StreamWriter(FileName))
    {
        var serializer = new XmlSerializer(this.GetType());
        serializer.Serialize(writer, this);
        writer.Flush();
    }
}

I used this code earlier. But reality showed that this solution is a bit problematic. Usually most of programmers just serialize setting on save and deserialize settings on load. This is an optimistic scenario. Once the serialization failed, because of some reason, the file is partly written, XML file is not complete and it is invalid. In consequence XML deserialization does not work and your application may crash on start. If the file is not huge, I suggest first serialize object to MemoryStream then write the stream to the File. This case is especially important if there is some complicated custom serialization. You can never test all cases.

public void Save(string fileName)
{
    //first serialize the object to memory stream,
    //in case of exception, the original file is not corrupted
    using (MemoryStream ms = new MemoryStream())
    {
        var writer = new System.IO.StreamWriter(ms);    
        var serializer = new XmlSerializer(this.GetType());
        serializer.Serialize(writer, this);
        writer.Flush();

        //if the serialization succeed, rewrite the file.
        File.WriteAllBytes(fileName, ms.ToArray());
    }
}

The deserialization in real world scenario should count with corrupted serialization file, it happens sometime. Load function provided by Ben Gripka is fine.

public static [ObjectType] Load(string fileName)
{
    using (var stream = System.IO.File.OpenRead(fileName))
    {
        var serializer = new XmlSerializer(typeof([ObjectType]));
        return serializer.Deserialize(stream) as [ObjectType];        
    }    
}

And it could be wrapped by some recovery scenario. It is suitable for settings files or other files which can be deleted in case of problems.

public static [ObjectType] LoadWithRecovery(string fileName)
{
    try
    {
        return Load(fileName);
    }
    catch(Excetion)
    {
        File.Delete(fileName); //delete corrupted settings file
        return GetFactorySettings();
    }
}

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

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

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

How to import JSON File into a TypeScript file?

Thanks for the input guys, I was able to find the fix, I added and defined the json on top of the app.component.ts file:

var json = require('./[yourFileNameHere].json');

This ultimately produced the markers and is a simple line of code.

SQL Current month/ year question

This should work for SQL Server:

SELECT * FROM myTable
WHERE month = DATEPART(m, GETDATE()) AND
year = DATEPART(yyyy, GETDATE())

Get user profile picture by Id

You can use the following endpoint to get the image.jfif instead of jpg:

https://graph.facebook.com/v3.2/{user-id}/picture

Note that you won't be able to see the image, only download it.

How can I convert an Integer to localized month name in Java?

There is an issue when you use DateFormatSymbols class for its getMonthName method to get Month by Name it show Month by Number in some Android devices. I have resolved this issue by doing this way:

In String_array.xml

<string-array name="year_month_name">
    <item>January</item>
    <item>February</item>
    <item>March</item>
    <item>April</item>
    <item>May</item>
    <item>June</item>
    <item>July</item>
    <item>August</item>
    <item>September</item>
    <item>October</item>
    <item>November</item>
    <item>December</item>
    </string-array>

In Java class just call this array like this way:

public String[] getYearMonthName() {
        return getResources().getStringArray(R.array.year_month_names);
        //or like 
       //return cntx.getResources().getStringArray(R.array.month_names);
    } 

      String[] months = getYearMonthName(); 
           if (i < months.length) {
            monthShow.setMonthName(months[i] + " " + year);

            }

Happy Coding :)

ExecutorService that interrupts tasks after a timeout

You can use this implementation that ExecutorService provides

invokeAll(Collection<? extends Callable<T>> tasks,long timeout, TimeUnit unit)
as

executor.invokeAll(Arrays.asList(task), 2 , TimeUnit.SECONDS);

However, in my case, I could not as Arrays.asList took extra 20ms.

Set selected item of spinner programmatically

To find a value and select it:

private void selectValue(Spinner spinner, Object value) {
    for (int i = 0; i < spinner.getCount(); i++) {
        if (spinner.getItemAtPosition(i).equals(value)) {
            spinner.setSelection(i);
            break;
        }
    }
}

How do I replace text inside a div element?

If you're inclined to start using a lot of JavaScript on your site, jQuery makes playing with the DOM extremely simple.

http://docs.jquery.com/Manipulation

Makes it as simple as: $("#field-name").text("Some new text.");

Calling Scalar-valued Functions in SQL

Make sure you have the correct database selected. You may have the master database selected if you are trying to run it in a new query window.

How does "make" app know default target to build if no target is specified?

To save others a few seconds, and to save them from having to read the manual, here's the short answer. Add this to the top of your make file:

.DEFAULT_GOAL := mytarget

mytarget will now be the target that is run if "make" is executed and no target is specified.

If you have an older version of make (<= 3.80), this won't work. If this is the case, then you can do what anon mentions, simply add this to the top of your make file:

.PHONY: default
default: mytarget ;

References: https://www.gnu.org/software/make/manual/html_node/How-Make-Works.html

Get escaped URL parameter

What you really want is the jQuery URL Parser plugin. With this plugin, getting the value of a specific URL parameter (for the current URL) looks like this:

$.url().param('foo');

If you want an object with parameter names as keys and parameter values as values, you'd just call param() without an argument, like this:

$.url().param();

This library also works with other urls, not just the current one:

$.url('http://allmarkedup.com?sky=blue&grass=green').param();
$('#myElement').url().param(); // works with elements that have 'src', 'href' or 'action' attributes

Since this is an entire URL parsing library, you can also get other information from the URL, like the port specified, or the path, protocol etc:

var url = $.url('http://allmarkedup.com/folder/dir/index.html?item=value');
url.attr('protocol'); // returns 'http'
url.attr('path'); // returns '/folder/dir/index.html'

It has other features as well, check out its homepage for more docs and examples.

Instead of writing your own URI parser for this specific purpose that kinda works in most cases, use an actual URI parser. Depending on the answer, code from other answers can return 'null' instead of null, doesn't work with empty parameters (?foo=&bar=x), can't parse and return all parameters at once, repeats the work if you repeatedly query the URL for parameters etc.

Use an actual URI parser, don't invent your own.

For those averse to jQuery, there's a version of the plugin that's pure JS.

Why aren't programs written in Assembly more often?

Why? Simple.

Compare this :

        for (var i = 1; i <= 100; i++)
        {
            if (i % 3 == 0)
                Console.Write("Fizz");
            if (i % 5 == 0)
                Console.Write("Buzz");
            if (i % 3 != 0 && i % 5 != 0)
                Console.Write(i);
            Console.WriteLine();
        }

with

.locals init (
    [0] int32 i)
L_0000: ldc.i4.1 
L_0001: stloc.0 
L_0002: br.s L_003b
L_0004: ldloc.0 
L_0005: ldc.i4.3 
L_0006: rem 
L_0007: brtrue.s L_0013
L_0009: ldstr "Fizz"
L_000e: call void [mscorlib]System.Console::Write(string)
L_0013: ldloc.0 
L_0014: ldc.i4.5 
L_0015: rem 
L_0016: brtrue.s L_0022
L_0018: ldstr "Buzz"
L_001d: call void [mscorlib]System.Console::Write(string)
L_0022: ldloc.0 
L_0023: ldc.i4.3 
L_0024: rem 
L_0025: brfalse.s L_0032
L_0027: ldloc.0 
L_0028: ldc.i4.5 
L_0029: rem 
L_002a: brfalse.s L_0032
L_002c: ldloc.0 
L_002d: call void [mscorlib]System.Console::Write(int32)
L_0032: call void [mscorlib]System.Console::WriteLine()
L_0037: ldloc.0 
L_0038: ldc.i4.1 
L_0039: add 
L_003a: stloc.0 
L_003b: ldloc.0 
L_003c: ldc.i4.s 100
L_003e: ble.s L_0004
L_0040: ret

They're identical feature-wise. The second one isn't even assembler but .NET IL (Intermediary Language, similar to Java's bytecode). The second compilation transforms the IL into native code (i.e. almost assembler), making it even more cryptical.

Naming Classes - How to avoid calling everything a "<WhatEver>Manager"?

When I find myself thinking about using Manager or Helper in a class name, I consider it a code smell that means I haven't found the right abstraction yet and/or I'm violating the single responsibility principle, so refactoring and putting more effort into design often makes naming much easier.

But even well-designed classes don't (always) name themselves, and your choices partly depend on whether you're creating business model classes or technical infrastructure classes.

Business model classes can be hard, because they're different for every domain. There are some terms I use a lot, like Policy for strategy classes within a domain (e.g., LateRentalPolicy), but these usually flow from trying to create a "ubiquitous language" that you can share with business users, designing and naming classes so they model real-world ideas, objects, actions, and events.

Technical infrastructure classes are a bit easier, because they describe domains we know really well. I prefer to incorporate design pattern names into the class names, like InsertUserCommand, CustomerRepository, or SapAdapter. I understand the concern about communicating implementation instead of intent, but design patterns marry these two aspects of class design - at least when you're dealing with infrastructure, where you want the implementation design to be transparent even while you're hiding the details.

How to enable or disable an anchor using jQuery?

 
$('#divID').addClass('disabledAnchor');

In css file

.disabledAnchor a{
       pointer-events: none !important;
       cursor: default;
       color:white;
}

Telnet is not recognized as internal or external command

You can try using Putty (freeware). It is mainly known as a SSH client, but you can use for Telnet login as well

How to pass in password to pg_dump?

You just need to open pg_hba.conf and sets trust in all methods. That's works for me. Therefore the security is null.

How display only years in input Bootstrap Datepicker?

For bootstrap 3 datepicker. (Note the capital letters)

$("#datetimepicker").datetimepicker( {
  format: "YYYY",
  viewMode: "years"
});

Cannot import XSSF in Apache POI

If you use Maven:

poi => poi-ooxml in artifactId

    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>3.12</version>
    </dependency>

postgresql duplicate key violates unique constraint

The primary key is already protecting you from inserting duplicate values, as you're experiencing when you get that error. Adding another unique constraint isn't necessary to do that.

The "duplicate key" error is telling you that the work was not done because it would produce a duplicate key, not that it discovered a duplicate key already commited to the table.

Watching variables in SSIS during debug

Visual Studio 2013: Yes to both adding to the watch windows during debugging and dragging variables or typing them in without "user::". But before any of that would work I also needed to go to Tools > Options, then Debugging > General and had to scroll right down to the bottom of the right hand pane to be able to tick "Use Managed Compatibility Mode". Then I had to stop and restart debugging. Finally the above advice worked. Many thanks to the above and to this article: Visual Studio 2015 Debugging: Can't expand local variables?

How to check certificate name and alias in keystore files?

This will list all certificates:

keytool -list -keystore "$JAVA_HOME/jre/lib/security/cacerts"

select a value where it doesn't exist in another table

You could use NOT IN:

SELECT A.* FROM A WHERE ID NOT IN(SELECT ID FROM B)

However, meanwhile i prefer NOT EXISTS:

SELECT A.* FROM A WHERE NOT EXISTS(SELECT 1 FROM B WHERE B.ID=A.ID)

There are other options as well, this article explains all advantages and disadvantages very well:

Should I use NOT IN, OUTER APPLY, LEFT OUTER JOIN, EXCEPT, or NOT EXISTS?

How to run C program on Mac OS X using Terminal?

First make sure you correct your program:

#include <stdio.h>

int main(void) {
   printf("Hello, world!\n"); //printf instead of pintf
   return 0;
}

Save the file as HelloWorld.c and type in the terminal:

gcc -o HelloWorld HelloWorld.c

Afterwards just run the executable like this:

./HelloWorld

You should be seeing Hello World!

How to completely uninstall Visual Studio 2010?

Best way I have used is to mount the VS 2010 Image or insert the Installation disc and run the uninstall option, really works well

How do I make an html link look like a button?

I use an asp:Button:

<asp:Button runat="server"
            OnClientClick="return location='targetPage', true;"
            UseSubmitBehavior="False"
            Text="Button Text Here"
/>

This way, the operation of the button is completely client-side and the button acts just like a link to the targetPage.

Centering in CSS Grid

Do not even try to use flex; stay with css grid!! :)

https://jsfiddle.net/ctt3bqr0/

place-self: center;

is doing the centering work here.

If you want to center something that is inside div that is inside grid cell you need to define nested grid in order to make it work. (Please look at the fiddle both examples shown there.)

https://css-tricks.com/snippets/css/complete-guide-grid/

Cheers!

Apache is not running from XAMPP Control Panel ( Error: Apache shutdown unexpectedly. This may be due to a blocked port)

If You installed SQL Express or any .Net Server then you need to stop. open cmd in administrator mode and type this line ...

net stop Was

now start apache