Programs & Examples On #Sp executesql

EXEC sp_executesql with multiple parameters

This also works....sometimes you may want to construct the definition of the parameters outside of the actual EXEC call.

DECLARE @Parmdef nvarchar (500)
DECLARE @SQL nvarchar (max)
DECLARE @xTxt1  nvarchar (100) = 'test1'
DECLARE @xTxt2  nvarchar (500) = 'test2' 
SET @parmdef = '@text1 nvarchar (100), @text2 nvarchar (500)'
SET @SQL = 'PRINT @text1 + '' '' + @text2'
EXEC sp_executeSQL @SQL, @Parmdef, @xTxt1, @xTxt2

How can I increase a scrollbar's width using CSS?

This can be done in WebKit-based browsers (such as Chrome and Safari) with only CSS:

::-webkit-scrollbar {
    width: 2em;
    height: 2em
}
::-webkit-scrollbar-button {
    background: #ccc
}
::-webkit-scrollbar-track-piece {
    background: #888
}
::-webkit-scrollbar-thumb {
    background: #eee
}?

JSFiddle Demo


References:

Difference between private, public, and protected inheritance

Summary:

  • Private: no one can see it except for within the class
  • Protected: Private + derived classes can see it
  • Public: the world can see it

When inheriting, you can (in some languages) change the protection type of a data member in certain direction, e.g. from protected to public.

How do you add PostgreSQL Driver as a dependency in Maven?

Depending on your PostgreSQL version you would need to add the postgresql driver to your pom.xml file.

For PostgreSQL 9.1 this would be:

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

    <name>Your project name.</name>
    <dependencies>
        <dependency>
            <groupId>postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>9.1-901-1.jdbc4</version>
        </dependency>
    </dependencies>
</project>

You can get the code for the dependency (as well as any other dependency) from maven's central repository

If you are using postgresql 9.2+:

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

    <name>Your project name.</name>
    <dependencies>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.1</version>
        </dependency>
    </dependencies>
</project>

You can check the latest versions and dependency snippets from:

How to hide axes and gridlines in Matplotlib (python)

Turn the axes off with:

plt.axis('off')

And gridlines with:

plt.grid(b=None)

"cannot resolve symbol R" in Android Studio

Dudes, I think there are a lot of shots in the dark here. In some cases Clean and Sync Project will help only after you fixed the problem.

Step1: So go and look at the top of each file where the package is specified as follows pakage="YourURL.YourProject"; and insure that the correct package (Your Own Project) is specified. You will find this in java files and AndroidManifest.xml and it is critical for the java files to reference the correct package, as that package contains the resources ("R") you are pointing to. Should they not match up the error cannot resolve Symbol R occurs.

Step2: Clean, Sync, whatever. Done

So why does this occur randomly or what did I do wrong??

If you copy and paste code, you should pay close attention to the "package=" as explained above. More importantly, when you paste code, it immediately runs through a sort of debugger (Excuse my bad tech term) to show you "presumed errors", which immediately takes in consideration the "Wrong Package", and you get all the errors. Therefore, even though you immediately corrected the notation after pasting, the debugger has already refreshed. Which is why "Clean, Sync, Whatever" works SOMETIMES

How do I run a program with commandline arguments using GDB within a Bash script?

Another way to do this, which I personally find slightly more convenient and intuitive (without having to remember the --args parameter), is to compile normally, and use r arg1 arg2 arg3 directly from within gdb, like so:

$ gcc -g *.c *.h
$ gdb ./a.out
(gdb) r arg1 arg2 arg3

Uncaught TypeError: Cannot set property 'onclick' of null

So I was having a similar issue and I managed to solve it by putting the script tag with my JS file after the closing body tag.

I assume it's because it makes sure there's something to reference, but I am not entirely sure.

Bootstrap: align input with button

I tried all the above codes and none of them fixed my issues. Here is what worked for me. I used input-group-addon.

<div class = "input-group">
  <span class = "input-group-addon">Go</span>
  <input type = "text" class = "form-control" placeholder="you are the man!">
</div>

How to prune local tracking branches that do not exist on remote anymore

Based on the answers above I'm using this shorter one liner:

git remote prune origin | awk 'BEGIN{FS="origin/"};/pruned/{print $2}' | xargs -r git branch -d

Also, if you already pruned and have local dangling branches, then this will clean them up:

git branch -vv | awk '/^ .*gone/{print $1}' | xargs -r git branch -d

Get the contents of a table row with a button click

The object of the exercise is to find the row that contains the information. When we get there, we can easily extract the required information.

Answer

$(".use-address").click(function() {
    var $item = $(this).closest("tr")   // Finds the closest row <tr> 
                       .find(".nr")     // Gets a descendent with class="nr"
                       .text();         // Retrieves the text within <td>

    $("#resultas").append($item);       // Outputs the answer
});

VIEW DEMO

Now let's focus on some frequently asked questions in such situations.

How to find the closest row?

Using .closest():

var $row = $(this).closest("tr");

Using .parent():

You can also move up the DOM tree using .parent() method. This is just an alternative that is sometimes used together with .prev() and .next().

var $row = $(this).parent()             // Moves up from <button> to <td>
                  .parent();            // Moves up from <td> to <tr>

Getting all table cell <td> values

So we have our $row and we would like to output table cell text:

var $row = $(this).closest("tr"),       // Finds the closest row <tr> 
    $tds = $row.find("td");             // Finds all children <td> elements

$.each($tds, function() {               // Visits every single <td> element
    console.log($(this).text());        // Prints out the text within the <td>
});

VIEW DEMO

Getting a specific <td> value

Similar to the previous one, however we can specify the index of the child <td> element.

var $row = $(this).closest("tr"),        // Finds the closest row <tr> 
    $tds = $row.find("td:nth-child(2)"); // Finds the 2nd <td> element

$.each($tds, function() {                // Visits every single <td> element
    console.log($(this).text());         // Prints out the text within the <td>
});

VIEW DEMO

Useful methods

  • .closest() - get the first element that matches the selector
  • .parent() - get the parent of each element in the current set of matched elements
  • .parents() - get the ancestors of each element in the current set of matched elements
  • .children() - get the children of each element in the set of matched elements
  • .siblings() - get the siblings of each element in the set of matched elements
  • .find() - get the descendants of each element in the current set of matched elements
  • .next() - get the immediately following sibling of each element in the set of matched elements
  • .prev() - get the immediately preceding sibling of each element in the set of matched elements

How to Initialize char array from a string

Weird error.

Can you test this?

const char* const S = "ABCD";
char t[] = { S[0], S[1], S[2], S[3] };
char u[] = { S[3], S[2], S[1], S[0] };

How to make inline plots in Jupyter Notebook larger?

The default figure size (in inches) is controlled by

matplotlib.rcParams['figure.figsize'] = [width, height]

For example:

import matplotlib.pyplot as plt
plt.rcParams['figure.figsize'] = [10, 5]

creates a figure with 10 (width) x 5 (height) inches

How do I convert a string to a double in Python?

The decimal operator might be more in line with what you are looking for:

>>> from decimal import Decimal
>>> x = "234243.434"
>>> print Decimal(x)
234243.434

Can I change the height of an image in CSS :before/:after pseudo-elements?

Adjusting the background-size is permitted. You still need to specify width and height of the block, however.

.pdflink:after {
    background-image: url('/images/pdf.png');
    background-size: 10px 20px;
    display: inline-block;
    width: 10px; 
    height: 20px;
    content:"";
}

See the full Compatibility Table at the MDN.

Pretty-Printing JSON with PHP

Classic case for a recursive solution. Here's mine:

class JsonFormatter {
    public static function prettyPrint(&$j, $indentor = "\t", $indent = "") {
        $inString = $escaped = false;
        $result = $indent;

        if(is_string($j)) {
            $bak = $j;
            $j = str_split(trim($j, '"'));
        }

        while(count($j)) {
            $c = array_shift($j);
            if(false !== strpos("{[,]}", $c)) {
                if($inString) {
                    $result .= $c;
                } else if($c == '{' || $c == '[') {
                    $result .= $c."\n";
                    $result .= self::prettyPrint($j, $indentor, $indentor.$indent);
                    $result .= $indent.array_shift($j);
                } else if($c == '}' || $c == ']') {
                    array_unshift($j, $c);
                    $result .= "\n";
                    return $result;
                } else {
                    $result .= $c."\n".$indent;
                } 
            } else {
                $result .= $c;
                $c == '"' && !$escaped && $inString = !$inString;
                $escaped = $c == '\\' ? !$escaped : false;
            }
        }

        $j = $bak;
        return $result;
    }
}

Usage:

php > require 'JsonFormatter.php';
php > $a = array('foo' => 1, 'bar' => 'This "is" bar', 'baz' => array('a' => 1, 'b' => 2, 'c' => '"3"'));
php > print_r($a);
Array
(
    [foo] => 1
    [bar] => This "is" bar
    [baz] => Array
        (
            [a] => 1
            [b] => 2
            [c] => "3"
        )

)
php > echo JsonFormatter::prettyPrint(json_encode($a));
{
    "foo":1,
    "bar":"This \"is\" bar",
    "baz":{
        "a":1,
        "b":2,
        "c":"\"3\""
    }
}

Cheers

How to concatenate strings in twig

The "{{ ... }}"-delimiter can also be used within strings:

"http://{{ app.request.host }}"

UDP vs TCP, how much faster is it?

I will just make things clear. TCP/UDP are two cars are that being driven on the road. suppose that traffic signs & obstacles are Errors TCP cares for traffic signs, respects everything around. Slow driving because something may happen to the car. While UDP just drives off, full speed no respect to street signs. Nothing, a mad driver. UDP doesn't have error recovery, If there's an obstacle, it will just collide with it then continue. While TCP makes sure that all packets are sent & received perfectly, No errors , so , the car just passes obstacles without colliding. I hope this is a good example for you to understand, Why UDP is preferred in gaming. Gaming needs speed. TCP is preffered in downloads, or downloaded files may be corrupted.

FPDF error: Some data has already been output, can't send PDF

For fpdf to work properly, there cannot be any output at all beside what fpdf generates. For example, this will work:

<?php
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10,'Hello World!');
$pdf->Output();
?>

While this will not (note the leading space before the opening <? tag)

 <?php
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10,'Hello World!');
$pdf->Output();
?>

Also, this will not work either (the echo will break it):

<?php
echo "About to create pdf";
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10,'Hello World!');
$pdf->Output();
?>

I'm not sure about the drupal side of things, but I know that absolutely zero non-fpdf output is a requirement for fpdf to work.


add ob_start (); at the top and at the end add ob_end_flush();

<?php
    ob_start();
    require('fpdf.php');
    $pdf = new FPDF();
    $pdf->AddPage();
    $pdf->SetFont('Arial','B',16);
    $pdf->Cell(40,10,'Hello World!');
    $pdf->Output();
    ob_end_flush(); 
?>

give me an error as below:
FPDF error: Some data has already been output, can't send PDF

to over come this error: go to fpdf.php in that,goto line number 996

function Output($name='', $dest='')

after that make changes like this:

function Output($name='', $dest='') {   
    ob_clean();     //Output PDF to so

Hi do you have a session header on the top of your page. or any includes If you have then try to add this codes on top pf your page it should works fine.

<?

while (ob_get_level())
ob_end_clean();
header("Content-Encoding: None", true);

?>

cheers :-)


In my case i had set:

ini_set('display_errors', 'on');
error_reporting(E_ALL | E_STRICT);

When i made the request to generate the report, some warnings were displayed in the browser (like the usage of deprecated functions).
Turning off the display_errors option, the report was generated successfully.

How to urlencode data for curl command?

Direct link to awk version : http://www.shelldorado.com/scripts/cmds/urlencode
I used it for years and it works like a charm

:
##########################################################################
# Title      :  urlencode - encode URL data
# Author     :  Heiner Steven ([email protected])
# Date       :  2000-03-15
# Requires   :  awk
# Categories :  File Conversion, WWW, CGI
# SCCS-Id.   :  @(#) urlencode  1.4 06/10/29
##########################################################################
# Description
#   Encode data according to
#       RFC 1738: "Uniform Resource Locators (URL)" and
#       RFC 1866: "Hypertext Markup Language - 2.0" (HTML)
#
#   This encoding is used i.e. for the MIME type
#   "application/x-www-form-urlencoded"
#
# Notes
#    o  The default behaviour is not to encode the line endings. This
#   may not be what was intended, because the result will be
#   multiple lines of output (which cannot be used in an URL or a
#   HTTP "POST" request). If the desired output should be one
#   line, use the "-l" option.
#
#    o  The "-l" option assumes, that the end-of-line is denoted by
#   the character LF (ASCII 10). This is not true for Windows or
#   Mac systems, where the end of a line is denoted by the two
#   characters CR LF (ASCII 13 10).
#   We use this for symmetry; data processed in the following way:
#       cat | urlencode -l | urldecode -l
#   should (and will) result in the original data
#
#    o  Large lines (or binary files) will break many AWK
#       implementations. If you get the message
#       awk: record `...' too long
#        record number xxx
#   consider using GNU AWK (gawk).
#
#    o  urlencode will always terminate it's output with an EOL
#       character
#
# Thanks to Stefan Brozinski for pointing out a bug related to non-standard
# locales.
#
# See also
#   urldecode
##########################################################################

PN=`basename "$0"`          # Program name
VER='1.4'

: ${AWK=awk}

Usage () {
    echo >&2 "$PN - encode URL data, $VER
usage: $PN [-l] [file ...]
    -l:  encode line endings (result will be one line of output)

The default is to encode each input line on its own."
    exit 1
}

Msg () {
    for MsgLine
    do echo "$PN: $MsgLine" >&2
    done
}

Fatal () { Msg "$@"; exit 1; }

set -- `getopt hl "$@" 2>/dev/null` || Usage
[ $# -lt 1 ] && Usage           # "getopt" detected an error

EncodeEOL=no
while [ $# -gt 0 ]
do
    case "$1" in
        -l) EncodeEOL=yes;;
    --) shift; break;;
    -h) Usage;;
    -*) Usage;;
    *)  break;;         # First file name
    esac
    shift
done

LANG=C  export LANG
$AWK '
    BEGIN {
    # We assume an awk implementation that is just plain dumb.
    # We will convert an character to its ASCII value with the
    # table ord[], and produce two-digit hexadecimal output
    # without the printf("%02X") feature.

    EOL = "%0A"     # "end of line" string (encoded)
    split ("1 2 3 4 5 6 7 8 9 A B C D E F", hextab, " ")
    hextab [0] = 0
    for ( i=1; i<=255; ++i ) ord [ sprintf ("%c", i) "" ] = i + 0
    if ("'"$EncodeEOL"'" == "yes") EncodeEOL = 1; else EncodeEOL = 0
    }
    {
    encoded = ""
    for ( i=1; i<=length ($0); ++i ) {
        c = substr ($0, i, 1)
        if ( c ~ /[a-zA-Z0-9.-]/ ) {
        encoded = encoded c     # safe character
        } else if ( c == " " ) {
        encoded = encoded "+"   # special handling
        } else {
        # unsafe character, encode it as a two-digit hex-number
        lo = ord [c] % 16
        hi = int (ord [c] / 16);
        encoded = encoded "%" hextab [hi] hextab [lo]
        }
    }
    if ( EncodeEOL ) {
        printf ("%s", encoded EOL)
    } else {
        print encoded
    }
    }
    END {
        #if ( EncodeEOL ) print ""
    }
' "$@"

How to create full path with node's fs.mkdirSync?

One option is to use shelljs module

npm install shelljs

var shell = require('shelljs');
shell.mkdir('-p', fullPath);

From that page:

Available options:

p: full path (will create intermediate dirs if necessary)

As others have noted, there's other more focused modules. But, outside of mkdirp, it has tons of other useful shell operations (like which, grep etc...) and it works on windows and *nix

Replace part of a string in Python?

>>> stuff = "Big and small"
>>> stuff.replace(" and ","/")
'Big/small'

Difference between SurfaceView and View?

One of the main differences between surfaceview and view is that to refresh the screen for a normal view we have to call invalidate method from the same thread where the view is defined. But even if we call invalidate, the refreshing does not happen immediately. It occurs only after the next arrival of the VSYNC signal. VSYNC signal is a kernel generated signal which happens every 16.6 ms or this is also known as 60 frame per second. So if we want more control over the refreshing of the screen (for example for very fast moving animation), we should not use normal view class.

On the other hand in case of surfaceview, we can refresh the screen as fast as we want and we can do it from a background thread. So refreshing of the surfaceview really does not depend upon VSYNC, and this is very useful if we want to do high speed animation. I have few training videos and example application which explain all these things nicely. Please have a look at the following training videos.

https://youtu.be/kRqsoApOr9U

https://youtu.be/Ji84HJ85FIQ

https://youtu.be/U8igPoyrUf8

How do I view the SQLite database on an Android device?

The best way I found so far is using the Android-Debug-Database tool.

Its incredibly simple to use and setup, just add the dependence and connect to the device database's interface via web. No need to root the phone or adding activities or whatsoever. Here are the steps:

STEP 1

Add the following dependency to your app's Gradle file and run the application.

debugCompile 'com.amitshekhar.android:debug-db:1.0.0'

STEP 2

Open your browser and visit your phone's IP address on port 8080. The URL should be like: http://YOUR_PHONE_IP_ADDRESS:8080. You will be presented with the following:

NOTE: You can also always get the debug address URL from your code by calling the method DebugDB.getAddressLog();

enter image description here

To get my phone's IP I currently use Ping Tools, but there are a lot of alternatives.

STEP 3

That's it!


More details in the official documentation: https://github.com/amitshekhariitbhu/Android-Debug-Database

Full screen background image in an activity

In lines with the answer of NoToast, you would need to have multiple versions of "your_image" in your res/drawable-ldpi,mdpi, hdpi, x-hdpi (for xtra large screens), remove match_parent and keep android: adjustViewBounds="true"

Double decimal formatting in Java

Use String.format:

String.format("%.2f", 4.52135);

As per docs:

The locale always used is the one returned by Locale.getDefault().

How do I run a batch script from within a batch script?

Run parallelly on separate command windows in minimized state

dayStart.bat

start "startOfficialSoftwares" /min cmd /k call startOfficialSoftwares.bat
start "initCodingEnvironment" /min cmd /k call initCodingEnvironment.bat
start "updateProjectSource" /min cmd /k call updateProjectSource.bat
start "runCoffeeMachine" /min cmd /k call runCoffeeMachine.bat

Run sequentially on same window

release.bat

call updateDevelVersion.bat
call mergeDevelIntoMaster.bat
call publishProject.bat

ArrayList of String Arrays

Following works in Java 8..

List<String[]> addresses = new ArrayList<>();

Is there a way to cast float as a decimal without rounding and preserving its precision?

Try SELECT CAST(field1 AS DECIMAL(10,2)) field1 and replace 10,2 with whatever precision you need.

Mock a constructor with parameter

With mockito you can use withSettings(), for example if the CounterService required 2 dependencies, you can pass them as a mock:

UserService userService = Mockito.mock(UserService.class); SearchService searchService = Mockito.mock(SearchService.class); CounterService counterService = Mockito.mock(CounterService.class, withSettings().useConstructor(userService, searchService));

What is a "bundle" in an Android application

use of bundle send data from one activity to another activity with the help of intent object; Bundle hold the data that can be any type.

Now I tell that how to create bundle passing data between two activity.

Step 1: On First activity

Bundle b=new Bundle();

b.putString("mkv",anystring);

Intent in=new Intent(getApplicationContext(),secondActivity.class);

in.putExtras(b);

startActivity(in);

Step 2: On Second Activity

Intent in=getIntent();

Bundle b=in.getExtras();

String s=b.getString("mkv");

I think this is useful for you...........

Looping through all rows in a table column, Excel-VBA

You can loop through the cells of any column in a table by knowing just its name and not its position. If the table is in sheet1 of the workbook:

Dim rngCol as Range
Dim cl as Range
Set rngCol = Sheet1.Range("TableName[ColumnName]")
For Each cl in rngCol
    cl.Value = "PHEV"
Next cl

The code above will loop through the data values only, excluding the header row and the totals row. It is not necessary to specify the number of rows in the table.

Use this to find the location of any column in a table by its column name:

Dim colNum as Long
colNum = Range("TableName[Column name to search for]").Column

This returns the numeric position of a column in the table.

How to post data using HttpClient?

Try to use this:

using (var handler = new HttpClientHandler() { CookieContainer = new CookieContainer() })
{
    using (var client = new HttpClient(handler) { BaseAddress = new Uri("site.com") })
    {
        //add parameters on request
        var body = new List<KeyValuePair<string, string>>
        {
            new KeyValuePair<string, string>("test", "test"),
            new KeyValuePair<string, string>("test1", "test1")
        };

        HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, "site.com");

        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/x-www-form-urlencoded; charset=UTF-8"));
        client.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1");
        client.DefaultRequestHeaders.Add("X-Requested-With", "XMLHttpRequest");
        client.DefaultRequestHeaders.Add("X-MicrosoftAjax", "Delta=true");
        //client.DefaultRequestHeaders.Add("Accept", "*/*");

        client.Timeout = TimeSpan.FromMilliseconds(10000);

        var res = await client.PostAsync("", new FormUrlEncodedContent(body));

        if (res.IsSuccessStatusCode)
        {
            var exec = await res.Content.ReadAsStringAsync();
            Console.WriteLine(exec);
        }                    
    }
}

How to run a Python script in the background even after I logout SSH?

If you've already started the process, and don't want to kill it and restart under nohup, you can send it to the background, then disown it.

Ctrl+Z (suspend the process)

bg (restart the process in the background

disown %1 (assuming this is job #1, use jobs to determine)

sql query distinct with Row_Number

This can be done very simple, you were pretty close already

SELECT distinct id, DENSE_RANK() OVER (ORDER BY  id) AS RowNum
FROM table
WHERE fid = 64

How to round the double value to 2 decimal points?

public static double addDoubles(double a, double b) {
        BigDecimal A = new BigDecimal(a + "");
        BigDecimal B = new BigDecimal(b + "");
        return A.add(B).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
    }

Python truncate a long string

Yet another solution. With True and False you get a little feedback about the test at the end.

data = {True: data[:75] + '..', False: data}[len(data) > 75]

MySQL 1062 - Duplicate entry '0' for key 'PRIMARY'

Set your PRIMARY KEY as AUTO_INCREMENT.

What is the difference between the float and integer data type when the size is the same?

  • float stores floating-point values, that is, values that have potential decimal places
  • int only stores integral values, that is, whole numbers

So while both are 32 bits wide, their use (and representation) is quite different. You cannot store 3.141 in an integer, but you can in a float.

Dissecting them both a little further:

In an integer, all bits are used to store the number value. This is (in Java and many computers too) done in the so-called two's complement. This basically means that you can represent the values of −231 to 231 − 1.

In a float, those 32 bits are divided between three distinct parts: The sign bit, the exponent and the mantissa. They are laid out as follows:

S EEEEEEEE MMMMMMMMMMMMMMMMMMMMMMM

There is a single bit that determines whether the number is negative or non-negative (zero is neither positive nor negative, but has the sign bit set to zero). Then there are eight bits of an exponent and 23 bits of mantissa. To get a useful number from that, (roughly) the following calculation is performed:

M × 2E

(There is more to it, but this should suffice for the purpose of this discussion)

The mantissa is in essence not much more than a 24-bit integer number. This gets multiplied by 2 to the power of the exponent part, which, roughly, is a number between −128 and 127.

Therefore you can accurately represent all numbers that would fit in a 24-bit integer but the numeric range is also much greater as larger exponents allow for larger values. For example, the maximum value for a float is around 3.4 × 1038 whereas int only allows values up to 2.1 × 109.

But that also means, since 32 bits only have 4.2 × 109 different states (which are all used to represent the values int can store), that at the larger end of float's numeric range the numbers are spaced wider apart (since there cannot be more unique float numbers than there are unique int numbers). You cannot represent some numbers exactly, then. For example, the number 2 × 1012 has a representation in float of 1,999,999,991,808. That might be close to 2,000,000,000,000 but it's not exact. Likewise, adding 1 to that number does not change it because 1 is too small to make a difference in the larger scales float is using there.

Similarly, you can also represent very small numbers (between 0 and 1) in a float but regardless of whether the numbers are very large or very small, float only has a precision of around 6 or 7 decimal digits. If you have large numbers those digits are at the start of the number (e.g. 4.51534 × 1035, which is nothing more than 451534 follows by 30 zeroes – and float cannot tell anything useful about whether those 30 digits are actually zeroes or something else), for very small numbers (e.g. 3.14159 × 10−27) they are at the far end of the number, way beyond the starting digits of 0.0000...

DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled

  • When you create a stored function, you must declare either that it is deterministic or that it does not modify data. Otherwise, it may be unsafe for data recovery or replication.

  • By default, for a CREATE FUNCTION statement to be accepted, at least one of DETERMINISTIC, NO SQL, or READS SQL DATA must be specified explicitly. Otherwise an error occurs:

To fix this issue add following lines After Return and Before Begin statement:

READS SQL DATA
DETERMINISTIC

For Example :

CREATE FUNCTION f2()
RETURNS CHAR(36) CHARACTER SET utf8
/*ADD HERE */
READS SQL DATA
DETERMINISTIC
BEGIN

For more detail about this issue please read Here

How can I store and retrieve images from a MySQL database using PHP?

i also recommend thinking this thru and then choosing to store images in your file system rather than the DB .. see here: Storing Images in DB - Yea or Nay?

CSS Styling for a Button: Using <input type="button> instead of <button>

Do you really want to style the <div>? Or do you want to style the <input type="button">? You should use the correct selector if you want the latter:

input[type=button] {
    color:#08233e;
    font:2.4em Futura, ‘Century Gothic’, AppleGothic, sans-serif;
    font-size:70%;
    /* ... other rules ... */
    cursor:pointer;
}

input[type=button]:hover {
    background-color:rgba(255,204,0,0.8);
}

See also:

How to tell if UIViewController's view is visible

if you're utilizing a UINavigationController and also want to handle modal views, the following is what i use:

#import <objc/runtime.h>

UIViewController* topMostController = self.navigationController.visibleViewController;
if([[NSString stringWithFormat:@"%s", class_getName([topMostController class])] isEqualToString:@"NAME_OF_CONTROLLER_YOURE_CHECKING_IN"]) {
    //is topmost visible view controller
}

Running vbscript from batch file

This is the command for the batch file and it can run the vbscript.

C:\Windows\SysWOW64\cmd.exe /c cscript C:\Windows\SysWOW64\...\necdaily.vbs

Check if element exists in jQuery

your elemId as its name suggests, is an Id attribute, these are all you can do to check if it exists:

Vanilla JavaScript: in case you have more advanced selectors:

//you can use it for more advanced selectors
if(document.querySelectorAll("#elemId").length){}

if(document.querySelector("#elemId")){}

//you can use it if your selector has only an Id attribute
if(document.getElementById("elemId")){}

jQuery:

if(jQuery("#elemId").length){}

Difference between pre-increment and post-increment in a loop?

a++ is known as postfix.

add 1 to a, returns the old value.

++a is known as prefix.

add 1 to a, returns the new value.

C#:

string[] items = {"a","b","c","d"};
int i = 0;
foreach (string item in items)
{
    Console.WriteLine(++i);
}
Console.WriteLine("");

i = 0;
foreach (string item in items)
{
    Console.WriteLine(i++);
}

Output:

1
2
3
4

0
1
2
3

foreach and while loops depend on which increment type you use. With for loops like below it makes no difference as you're not using the return value of i:

for (int i = 0; i < 5; i++) { Console.Write(i);}
Console.WriteLine("");
for (int i = 0; i < 5; ++i) { Console.Write(i); }

0 1 2 3 4
0 1 2 3 4

If the value as evaluated is used then the type of increment becomes significant:

int n = 0;
for (int i = 0; n < 5; n = i++) { }

How can I check for IsPostBack in JavaScript?

Create a global variable in and apply the value

<script>
       var isPostBack = <%=Convert.ToString(Page.IsPostBack).ToLower()%>;
</script>

Then you can reference it from elsewhere

Loading scripts after page load?

For a Progressive Web App I wrote a script to easily load javascript files async on demand. Scripts are only loaded once. So you can call loadScript as often as you want for the same file. It wouldn't be loaded twice. This script requires JQuery to work.

For example:

loadScript("js/myscript.js").then(function(){
    // Do whatever you want to do after script load
});

or when used in an async function:

await loadScript("js/myscript.js");
// Do whatever you want to do after script load

In your case you may execute this after document ready:

$(document).ready(async function() {
    await loadScript("js/myscript.js");
    // Do whatever you want to do after script is ready
});

Function for loadScript:

function loadScript(src) {
  return new Promise(function (resolve, reject) {
    if ($("script[src='" + src + "']").length === 0) {
        var script = document.createElement('script');
        script.onload = function () {
            resolve();
        };
        script.onerror = function () {
            reject();
        };
        script.src = src;
        document.body.appendChild(script);
    } else {
        resolve();
    }
});
}

Benefit of this way:

  • It uses browser cache
  • You can load the script file when a user performs an action which needs the script instead loading it always.

Clearing content of text file using php

Use 'w' and not, 'a'.

if (!$handle = fopen($file, 'w'))

IIS7 URL Redirection from root to sub directory

Here it is. Add this code to your web.config file:

<system.webServer>
    <rewrite>
        <rules>
            <rule name="Root Hit Redirect" stopProcessing="true">
                <match url="^$" />
                <action type="Redirect" url="/menu_1/MainScreen.aspx" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

It will do 301 Permanent Redirect (URL will be changed in browser). If you want to have such "redirect" to be invisible (rewrite, internal redirect), then use this rule (the only difference is that "Redirect" has been replaced by "Rewrite"):

<system.webServer>
    <rewrite>
        <rules>
            <rule name="Root Hit Redirect" stopProcessing="true">
                <match url="^$" />
                <action type="Rewrite" url="/menu_1/MainScreen.aspx" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

Java ElasticSearch None of the configured nodes are available

I spend days together to figure out this issue. I know its late but this might be helpful:

I resolved this issue by changing the compatible/stable version of:

Spring boot: 2.1.1
Spring Data Elastic: 2.1.4
Elastic: 6.4.0 (default)

Maven:

<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.1.RELEASE</version>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
<version>2.1.4.RELEASE</version>
</dependency>

<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
</dependency>

You don't need to mention Elastic version. By default it is 6.4.0. But if you want to add a specific verison. Use below snippet inside properties tag and use the compatible version of Spring Boot and Spring Data(if required)

<properties>
<elasticsearch.version>6.8.0</elasticsearch.version>
</properties>

Also, I used the Rest High Level client in ElasticConfiguration :

@Value("${elasticsearch.host}")
public String host;

@Value("${elasticsearch.port}")
public int port;

@Bean(destroyMethod = "close")
public RestHighLevelClient restClient1() {
    final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
    RestClientBuilder builder = RestClient.builder(new HttpHost(host, port));
    RestHighLevelClient client = new RestHighLevelClient(builder);
    return client;
    }
}

Important Note: Elastic use 9300 port to communicate between nodes and 9200 as HTTP client. In application properties:

elasticsearch.host=10.40.43.111
elasticsearch.port=9200

spring.data.elasticsearch.cluster-nodes=10.40.43.111:9300 (customized Elastic server)
spring.data.elasticsearch.cluster-name=any-cluster-name (customized cluster name)

From Postman, you can use: http://10.40.43.111:9200/[indexname]/_search

Happy coding :)

Get MAC address using shell script

Here's an alternative answer in case the ones listed above don't work for you. You can use the following solution(s) as well, which was found here:

ip addr

OR

ip addr show

OR

ip link

All three of these will show your MAC address(es) next to link/ether. I stumbled on this because I had just done a fresh install of Debian 9.5 from a USB stick without internet access, so I could only do a very minimal install, and received

-bash: ifconfig: command not found

when I tried some of the above solutions. I figured somebody else may come across this problem as well. Hope it helps.

Programmatically retrieve SQL Server stored procedure source that is identical to the source returned by the SQL Server Management Studio gui?

EXEC sp_helptext 'your procedure name';

This avoids the problem with INFORMATION_SCHEMA approach wherein the stored procedure gets cut off if it is too long.

Update: David writes that this isn't identical to his sproc...perhaps because it returns the lines as 'records' to preserve formatting? If you want to see the results in a more 'natural' format, you can use Ctrl-T first (output as text) and it should print it out exactly as you've entered it. If you are doing this in code, it is trivial to do a foreach to put together your results in exactly the same way.

Update 2: This will provide the source with a "CREATE PROCEDURE" rather than an "ALTER PROCEDURE" but I know of no way to make it use "ALTER" instead. Kind of a trivial thing, though, isn't it?

Update 3: See the comments for some more insight on how to maintain your SQL DDL (database structure) in a source control system. That is really the key to this question.

What is the point of the diamond operator (<>) in Java 7?

In theory, the diamond operator allows you to write more compact (and readable) code by saving repeated type arguments. In practice, it's just two confusing chars more giving you nothing. Why?

  1. No sane programmer uses raw types in new code. So the compiler could simply assume that by writing no type arguments you want it to infer them.
  2. The diamond operator provides no type information, it just says the compiler, "it'll be fine". So by omitting it you can do no harm. At any place where the diamond operator is legal it could be "inferred" by the compiler.

IMHO, having a clear and simple way to mark a source as Java 7 would be more useful than inventing such strange things. In so marked code raw types could be forbidden without losing anything.

Btw., I don't think that it should be done using a compile switch. The Java version of a program file is an attribute of the file, no option at all. Using something as trivial as

package 7 com.example;

could make it clear (you may prefer something more sophisticated including one or more fancy keywords). It would even allow to compile sources written for different Java versions together without any problems. It would allow introducing new keywords (e.g., "module") or dropping some obsolete features (multiple non-public non-nested classes in a single file or whatsoever) without losing any compatibility.

PHP decoding and encoding json with unicode characters

Judging from everything you've said, it seems like the original Odómetro string you're dealing with is encoded with ISO 8859-1, not UTF-8.

Here's why I think so:

  • json_encode produced parseable output after you ran the input string through utf8_encode, which converts from ISO 8859-1 to UTF-8.
  • You did say that you got "mangled" output when using print_r after doing utf8_encode, but the mangled output you got is actually exactly what would happen by trying to parse UTF-8 text as ISO 8859-1 (ó is \x63\xb3 in UTF-8, but that sequence is ó in ISO 8859-1.
  • Your htmlentities hackaround solution worked. htmlentities needs to know what the encoding of the input string to work correctly. If you don't specify one, it assumes ISO 8859-1. (html_entity_decode, confusingly, defaults to UTF-8, so your method had the effect of converting from ISO 8859-1 to UTF-8.)
  • You said you had the same problem in Python, which would seem to exclude PHP from being the issue.

PHP will use the \uXXXX escaping, but as you noted, this is valid JSON.

So, it seems like you need to configure your connection to Postgres so that it will give you UTF-8 strings. The PHP manual indicates you'd do this by appending options='--client_encoding=UTF8' to the connection string. There's also the possibility that the data currently stored in the database is in the wrong encoding. (You could simply use utf8_encode, but this will only support characters that are part of ISO 8859-1).

Finally, as another answer noted, you do need to make sure that you're declaring the proper charset, with an HTTP header or otherwise (of course, this particular issue might have just been an artifact of the environment where you did your print_r testing).

How to create a session using JavaScript?

You can try jstorage javascript plugin, it is an elegant way to maintain sessions check this http://www.jstorage.info/

include the jStorage.js script into your html

<script src="jStorage.js"></script>

Then in your javascript place the sessiontoken into the a key like this

$.jStorage.set("YOUR_KEY",session_id);

Where "YOUR_KEY" is the key using which you can access you session_id , like this:

var id = $.jStorage.get("YOUR_KEY");

error: use of deleted function

The error message clearly says that the default constructor has been deleted implicitly. It even says why: the class contains a non-static, const variable, which would not be initialized by the default ctor.

class X {
    const int x;
};

Since X::x is const, it must be initialized -- but a default ctor wouldn't normally initialize it (because it's a POD type). Therefore, to get a default ctor, you need to define one yourself (and it must initialize x). You can get the same kind of situation with a member that's a reference:

class X { 
    whatever &x;
};

It's probably worth noting that both of these will also disable implicit creation of an assignment operator as well, for essentially the same reason. The implicit assignment operator normally does members-wise assignment, but with a const member or reference member, it can't do that because the member can't be assigned. To make assignment work, you need to write your own assignment operator.

This is why a const member should typically be static -- when you do an assignment, you can't assign the const member anyway. In a typical case all your instances are going to have the same value so they might as well share access to a single variable instead of having lots of copies of a variable that will all have the same value.

It is possible, of course, to create instances with different values though -- you (for example) pass a value when you create the object, so two different objects can have two different values. If, however, you try to do something like swapping them, the const member will retain its original value instead of being swapped.

How to Free Inode Usage?

If you use docker, remove all images. They used many space....

Stop all containers

docker stop $(docker ps -a -q)

Delete all containers

docker rm $(docker ps -a -q)

Delete all images

docker rmi $(docker images -q)

Works to me

If a folder does not exist, create it

Directory.CreateDirectory explains how to try and to create the FilePath if it does not exist.

Directory.Exists explains how to check if a FilePath exists. However, you don't need this as CreateDirectory will check it for you.

Error:attempt to apply non-function

I got the error because of a clumsy typo:

This errors:

knitr::opts_chunk$seet(echo = FALSE)

Error: attempt to apply non-function

After correcting the typo, it works:

knitr::opts_chunk$set(echo = FALSE)

Unable to connect to SQL Express "Error: 26-Error Locating Server/Instance Specified)

All you need to do is to go to the control panel > Computer Management > Services and manually start the SQL express or SQL server. It worked for me.

Good luck.

Insert all data of a datagridview to database at once

Please see if below can help you

Class Post_Sales

Public Shared Sub Post_sales()

    Dim ITM_ID As Integer

    Dim SLS_QTY As Integer

    Dim SLS_PRC As Double

    Dim SLS_AMT As Double

    Dim DSPL_RCT As String

    Dim TAX_CODE As Integer


    'Format the current  date and send it to a textbox
    Form1.TextBox6.Text = System.DateTime.Now.ToString((" yyyy-MM-dd"))

    'Open Connection

    Dim con As New SqlConnection("Initial Catalog=Your Database here;Data source=.;Network Library=DBMSSOCN;User ID=sa;Password=")

    con.Open()

    'Insert Records into the database


    For Each rw As DataGridViewRow In Form1.DataGridView1.Rows

        ITM_ID = rw.Cells("Column1").Value
        DSPL_RCT = rw.Cells("Column2").Value
        SLS_QTY = rw.Cells("Column3").Value
        SLS_PRC = rw.Cells("Column4").Value
        SLS_AMT = rw.Cells("Column5").Value
        TAX_CODE = rw.Cells("Column6").Value

        Dim cmd As New SqlCommand("INSERT INTO DAY_PLUSALES (DT,ITM_ID,DSPL_RCT,SLS_QTY,SLS_PRC,SLS_AMT,TAX_CODE) values ('" & Form1.TextBox6.Text & "','" & ITM_ID & "','" & DSPL_RCT & "','" & SLS_QTY & "','" & SLS_PRC & "','" & SLS_AMT & "','" & TAX_CODE & "')", con)

        cmd.ExecuteNonQuery()

    Next

    con.Close()

    MessageBox.Show("Records Added to the SQL Database successfully!", "Records Updated ")

End Sub

End Class

MySQLi count(*) always returns 1

I find this way more readable:

$result = $mysqli->query('select count(*) as `c` from `table`');
$count = $result->fetch_object()->c;
echo "there are {$count} rows in the table";

Not that I have anything against arrays...

How to create a DOM node as an object?

There are three reasons why your example fails.

  1. The original 'template' variable is not a jQuery/DOM object and cannot be parsed, it is a string. Make it a jQuery object by wrapping it in $(), such as: template = $(template)

  2. Once the 'template' variable is a jQuery object you need to realize that <li> is the root object. Therefore you cannot search for the LI root node and get any results. Simply apply the ID to the jQuery object.

  3. When you assign an ID to an HTML element it cannot begin with a number character with any HTML version before HTML5. It must begin with an alphabetic character. With HTML5 this can be any non-whitespace character. For details refer to: What are valid values for the id attribute in HTML?

PS: A final issue with the sample code is an LI cannot be applied to the BODY. According to HTML requirements it must always be contained within a list, i.e. UL or OL.

CentOS: Copy directory to another directory

This works for me.

cp -r /home/server/folder/test/. /home/server

Change "on" color of a Switch

The solution suggested from arlomedia worked for me. About his issue of extraspace I solved removing all the paddings to the switch.

EDIT

As requested, here what I have.

In the layout file, my switch is inside a linear layout and after a TextView.

<LinearLayout
        android:id="@+id/myLinearLayout"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_gravity="center_horizontal|center"
        android:gravity="right"
        android:padding="10dp"
        android:layout_marginTop="0dp"
        android:background="@drawable/bkg_myLinearLayout"
        android:layout_marginBottom="0dp">
        <TextView
            android:id="@+id/myTextForTheSwitch"
            android:layout_height="wrap_content"
            android:text="@string/TextForTheSwitch"
            android:textSize="18sp"
            android:layout_centerHorizontal="true"
            android:layout_gravity="center_horizontal|center"
            android:gravity="right"
            android:layout_width="wrap_content"
            android:paddingRight="20dp"
            android:textColor="@color/text_white" />
        <Switch
            android:id="@+id/mySwitch"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textOn="@string/On"
            android:textOff="@string/Off"
            android:layout_centerHorizontal="true"
            android:layout_gravity="center_horizontal"
            android:layout_toRightOf="@id/myTextForTheSwitch"
            android:layout_alignBaseline="@id/myTextForTheSwitch"
            android:gravity="right" />
    </LinearLayout>

Since I'm working with Xamarin / Monodroid (min. Android 4.1) my code is:

Android.Graphics.Color colorOn = Android.Graphics.Color.Green;
Android.Graphics.Color colorOff = Android.Graphics.Color.Gray;
Android.Graphics.Color colorDisabled = Android.Graphics.Color.Green;

StateListDrawable drawable = new StateListDrawable();
drawable.AddState(new int[] { Android.Resource.Attribute.StateChecked }, new ColorDrawable(colorOn));
drawable.AddState(new int[] { -Android.Resource.Attribute.StateEnabled }, new ColorDrawable(colorDisabled));
drawable.AddState(new int[] { }, new ColorDrawable(colorOff));

swtch_EnableEdit.ThumbDrawable = drawable;

swtch_EnableEdit is previously defined like this (Xamarin):

Switch swtch_EnableEdit = view.FindViewById<Switch>(Resource.Id.mySwitch);

I don't set at all the paddings and I don't call .setPadding(0, 0, 0, 0).

How do I get a value of datetime.today() in Python that is "timezone aware"?

Getting a timezone-aware date in utc timezone is enough for date subtraction to work.

But if you want a timezone-aware date in your current time zone, tzlocal is the way to go:

from tzlocal import get_localzone  # pip install tzlocal
from datetime import datetime
datetime.now(get_localzone())

PS dateutil has a similar function (dateutil.tz.tzlocal). But inspite of sharing the name it has a completely different code base, which as noted by J.F. Sebastian can give wrong results.

How much RAM is SQL Server actually using?

  1. Start -> Run -> perfmon
  2. Look at the zillions of counters that SQL Server installs

How to install CocoaPods?

Cocoapods Installation on macOS High Sierra:

  1. Install Homebrew https://brew.sh/

  2. Execute following commands in terminal:

sudo gem update --system   
sudo gem install activesupport -v 4.2.6

sudo gem install -n /usr/local/bin cocoapods

pod setup

pod setup --verbose

Chrome hangs after certain amount of data transfered - waiting for available socket

Looks like you are hitting the limit on connections per server. I see you are loading a lot of static files and my advice is to separate them on subdomains and serve them directly with Nginx for example.

  • Create a subdomain called img.yoursite.com and load all your images from there.

  • Create a subdomain called scripts.yourdomain.com and load all your JS and CSS files from there.

  • Create a subdomain called sounds.yoursite.com and load all your MP3s from there... etc..

Nginx has great options for directly serving static files and managing the static files caching.

how to find 2d array size in c++

#include<iostream>
using namespace std ;
int main()
{
    int A[3][4] = { {1,2,3,4} , {4,5,7,8} , {9,10,11,12} } ;
    for(int rows=0 ; rows<sizeof(A)/sizeof(*A) ; rows++)
    {
        for(int columns=0 ; columns< sizeof(*A) / sizeof(*A[0]) ; columns++)
        {
            cout<<A[rows][columns] <<"\t" ;
        }
        cout<<endl ;
    }
}

Multi-threading in VBA

Can't be done natively with VBA. VBA is built in a single-threaded apartment. The only way to get multiple threads is to build a DLL in something other than VBA that has a COM interface and call it from VBA.

INFO: Descriptions and Workings of OLE Threading Models

How to insert data to MySQL having auto incremented primary key?

Check out this post

According to it

No value was specified for the AUTO_INCREMENT column, so MySQL assigned sequence numbers automatically. You can also explicitly assign NULL or 0 to the column to generate sequence numbers.

Is JavaScript object-oriented?

JavaScript is a prototype-based programming language (probably prototype-based scripting language is more correct definition). It employs cloning and not inheritance. A prototype-based programming language is a style of object-oriented programming without classes. While object-oriented programming languages encourages development focus on taxonomy and relationships, prototype-based programming languages encourages to focus on behavior first and then later classify.

The term “object-oriented” was coined by Alan Kay in 1967, who explains it in 2003 to mean

only messaging, local retention and protection and hiding of state-process, and extreme late-binding of all things. (source)

In object-oriented programming, each object is capable of receiving messages, processing data, and sending messages to other objects.

For a language to be object-oriented in may include features as encapsulation, modularity, polymorphism, and inheritance, but it is not a requirement. Object-oriented programming languages that make use of classes are often referred to as classed-based programming languages, but it is by no means a must to make use of classes to be object-oriented.

JavaScript uses prototypes to define object properties, including methods and inheritance.

Conclusion: JavaScript IS object-oriented.

No mapping found for HTTP request with URI Spring MVC

First check whether the java classes are compiled or not in your [PROJECT_NAME]\target\classes directory.

If not you have some compilation errors in your java classes.

Pass Parameter to Gulp Task

It's a feature programs cannot stay without. You can try yargs.

npm install --save-dev yargs

You can use it like this:

gulp mytask --production --test 1234

In the code, for example:

var argv = require('yargs').argv;
var isProduction = (argv.production === undefined) ? false : true;

For your understanding:

> gulp watch
console.log(argv.production === undefined);  <-- true
console.log(argv.test === undefined);        <-- true

> gulp watch --production
console.log(argv.production === undefined);  <-- false
console.log(argv.production);                <-- true
console.log(argv.test === undefined);        <-- true
console.log(argv.test);                      <-- undefined

> gulp watch --production --test 1234
console.log(argv.production === undefined);  <-- false
console.log(argv.production);                <-- true
console.log(argv.test === undefined);        <-- false
console.log(argv.test);                      <-- 1234

Hope you can take it from here.

There's another plugin that you can use, minimist. There's another post where there's good examples for both yargs and minimist: (Is it possible to pass a flag to Gulp to have it run tasks in different ways?)

Is String.Contains() faster than String.IndexOf()?

By using Reflector, you can see, that Contains is implemented using IndexOf. Here's the implementation.

public bool Contains(string value)
{
   return (this.IndexOf(value, StringComparison.Ordinal) >= 0);
}

So Contains is likely a wee bit slower than calling IndexOf directly, but I doubt that it will have any significance for the actual performance.

Is there a Google Sheets formula to put the name of the sheet into a cell?

I have a sheet that is made to used by others and I have quite a few indirect() references around, so I need to formulaically handle a changed sheet tab name.

I used the formula from JohnP2 (below) but was having trouble because it didn't update automatically when a sheet name was changed. You need to go to the actual formula, make an arbitrary change and refresh to run it again.

=REGEXREPLACE(CELL("address",'SHEET NAME'!A1),"'?([^']+)'?!.*","$1")

I solved this by using info found in this solution on how to force a function to refresh. It may not be the most elegant solution, but it forced Sheets to pay attention to this cell and update it regularly, so that it catches an updated sheet title.

=IF(TODAY()=TODAY(), REGEXREPLACE(CELL("address",'SHEET NAME'!A1),"'?([^']+)'?!.*","$1"), "")

Using this, Sheets know to refresh this cell every time you make a change, which results in the address being updated whenever it gets renamed by a user.

Two dimensional array in python

You can first append elements to the initialized array and then for convenience, you can convert it into a numpy array.

import numpy as np
a = [] # declare null array
a.append(['aa1']) # append elements
a.append(['aa2'])
a.append(['aa3'])
print(a)
a_np = np.asarray(a) # convert to numpy array
print(a_np)

Google Chrome forcing download of "f.txt" file

FYI, after reading this thread, I took a look at my installed programs and found that somehow, shortly after upgrading to Windows 10 (possibly/probably? unrelated), an ASK search app was installed as well as a Chrome extension (Windows was kind enough to remind to check that). Since removing, I have not have the f.txt issue.

How to create a testflight invitation code?

after you add the user for testing. the user should get an email. open that email by your iOS device, then click "Start testing" it will bring you to testFlight to download the app directly. If you open that email via computer, and then click "Start testing" it will show you another page which have the instruction of how to install the app. and that invitation code is on the last line. those All upper case letters is the code.

HTTP POST with URL query parameters -- good idea or not?

I would think it could still be quite RESTful to have query arguments that identify the resource on the URL while keeping the content payload confined to the POST body. This would seem to separate the considerations of "What am I sending?" versus "Who am I sending it to?".

pyplot scatter plot marker size

You can use markersize to specify the size of the circle in plot method

import numpy as np
import matplotlib.pyplot as plt

x1 = np.random.randn(20)
x2 = np.random.randn(20)
plt.figure(1)
# you can specify the marker size two ways directly:
plt.plot(x1, 'bo', markersize=20)  # blue circle with size 10 
plt.plot(x2, 'ro', ms=10,)  # ms is just an alias for markersize
plt.show()

From here

enter image description here

Java "user.dir" property - what exactly does it mean?

user.dir is the "User working directory" according to the Java Tutorial, System Properties

How to plot data from multiple two column text files with legends in Matplotlib?

I feel the simplest way would be

 from matplotlib import pyplot;
 from pylab import genfromtxt;  
 mat0 = genfromtxt("data0.txt");
 mat1 = genfromtxt("data1.txt");
 pyplot.plot(mat0[:,0], mat0[:,1], label = "data0");
 pyplot.plot(mat1[:,0], mat1[:,1], label = "data1");
 pyplot.legend();
 pyplot.show();
  1. label is the string that is displayed on the legend
  2. you can plot as many series of data points as possible before show() to plot all of them on the same graph This is the simple way to plot simple graphs. For other options in genfromtxt go to this url.

Fit website background image to screen size

you can do this with this plugin http://dev.andreaseberhard.de/jquery/superbgimage/

or

   background-image:url(../IMAGES/background.jpg);

   background-repeat:no-repeat;

   background-size:cover;

with no need the prefixes of browsers. it's all ready suporterd in both of browers

Working around MySQL error "Deadlock found when trying to get lock; try restarting transaction"

The answer is correct, however the perl documentation on how to handle deadlocks is a bit sparse and perhaps confusing with PrintError, RaiseError and HandleError options. It seems that rather than going with HandleError, use on Print and Raise and then use something like Try:Tiny to wrap your code and check for errors. The below code gives an example where the db code is inside a while loop that will re-execute an errored sql statement every 3 seconds. The catch block gets $_ which is the specific err message. I pass this to a handler function "dbi_err_handler" which checks $_ against a host of errors and returns 1 if the code should continue (thereby breaking the loop) or 0 if its a deadlock and should be retried...

$sth = $dbh->prepare($strsql);
my $db_res=0;
while($db_res==0)
{
   $db_res=1;
   try{$sth->execute($param1,$param2);}
   catch
   {
       print "caught $_ in insertion to hd_item_upc for upc $upc\n";
       $db_res=dbi_err_handler($_); 
       if($db_res==0){sleep 3;}
   }
}

dbi_err_handler should have at least the following:

sub dbi_err_handler
{
    my($message) = @_;
    if($message=~ m/DBD::mysql::st execute failed: Deadlock found when trying to get lock; try restarting transaction/)
    {
       $caught=1;
       $retval=0; # we'll check this value and sleep/re-execute if necessary
    }
    return $retval;
}

You should include other errors you wish to handle and set $retval depending on whether you'd like to re-execute or continue..

Hope this helps someone -

How to pass variable as a parameter in Execute SQL Task SSIS?

SELECT, INSERT, UPDATE, and DELETE commands frequently include WHERE clauses to specify filters that define the conditions each row in the source tables must meet to qualify for an SQL command. Parameters provide the filter values in the WHERE clauses.

You can use parameter markers to dynamically provide parameter values. The rules for which parameter markers and parameter names can be used in the SQL statement depend on the type of connection manager that the Execute SQL uses.

The following table lists examples of the SELECT command by connection manager type. The INSERT, UPDATE, and DELETE statements are similar. The examples use SELECT to return products from the Product table in AdventureWorks2012 that have a ProductID greater than and less than the values specified by two parameters.

EXCEL, ODBC, and OLEDB

SELECT* FROM Production.Product WHERE ProductId > ? AND ProductID < ?

ADO

SELECT * FROM Production.Product WHERE ProductId > ? AND ProductID < ?

ADO.NET

SELECT* FROM Production.Product WHERE ProductId > @parmMinProductID 
     AND ProductID < @parmMaxProductID

The examples would require parameters that have the following names: The EXCEL and OLED DB connection managers use the parameter names 0 and 1. The ODBC connection type uses 1 and 2. The ADO connection type could use any two parameter names, such as Param1 and Param2, but the parameters must be mapped by their ordinal position in the parameter list. The ADO.NET connection type uses the parameter names @parmMinProductID and @parmMaxProductID.

How to use "not" in xpath?

Use boolean function like below:

//a[(contains(@id, 'xx'))=false]

justify-content property isn't working

Screenshot

Go to inspect element and check if .justify-content-center is listed as a class name under 'Styles' tab. If not, probably you are using bootstrap v3 in which justify-content-center is not defined.

If so, please update bootstrap, worked for me.

Shortcut to exit scale mode in VirtualBox

Steps:

  • host + f, to switch to full screen mode, if not yet,
  • host + c, to switch to/out of scaled mode,
  • host + f, to switch back normal size, if need,

Tip:

  • host key, default to right ctrl, the control button on right part of your keyboard,
  • host + c seems only work in fullscreen mode,

How to change maven logging level to display only warning and errors?

Changing the info to error in simplelogging.properties file will help in achieving your requirement.

Just change the value of the below line

org.slf4j.simpleLogger.defaultLogLevel=info 

to

org.slf4j.simpleLogger.defaultLogLevel=error

Remove Android App Title Bar

Use this Remove title and image from top.

Before:

setContentView(R.layout.actii);

Write this code:

requestWindowFeature(Window.FEATURE_NO_TITLE);

Giving multiple conditions in for loop in Java

You can also replace complicated condition with single method call to make it less evil in maintain.

jQuery: count number of rows in a table

Alternatively...

var rowCount = $('table#myTable tr:last').index() + 1;

jsFiddle DEMO

This will ensure that any nested table-rows are not also counted.

Adding a tooltip to an input box

Apart from HTML 5 data-tip You can use css also for making a totally customizable tooltip to be used anywhere throughout your markup.

_x000D_
_x000D_
/* ToolTip classses */ _x000D_
.tooltip {_x000D_
    display: inline-block;    _x000D_
}_x000D_
.tooltip .tooltiptext {_x000D_
    margin-left:9px;_x000D_
    width : 320px;_x000D_
    visibility: hidden;_x000D_
    background-color: #FFF;_x000D_
    border-radius:4px;_x000D_
    border: 1px solid #aeaeae;_x000D_
    position: absolute;_x000D_
    z-index: 1;_x000D_
    padding: 5px;_x000D_
    margin-top : -15px; _x000D_
    opacity: 0;_x000D_
    transition: opacity 0.5s;_x000D_
}_x000D_
.tooltip .tooltiptext::after {_x000D_
    content: " ";_x000D_
    position: absolute;_x000D_
    top: 5%;_x000D_
    right: 100%;  _x000D_
    margin-top: -5px;_x000D_
    border-width: 5px;_x000D_
    border-style: solid;_x000D_
    border-color: transparent #aeaeae transparent transparent;_x000D_
}_x000D_
_x000D_
_x000D_
.tooltip:hover .tooltiptext {_x000D_
    visibility: visible;_x000D_
    opacity: 1;_x000D_
}
_x000D_
<div class="tooltip">_x000D_
  <input type="text" />_x000D_
  <span class="tooltiptext">_x000D_
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.  </span>_x000D_
</div>
_x000D_
_x000D_
_x000D_

MacOS Xcode CoreSimulator folder very big. Is it ok to delete content?

Try to run xcrun simctl delete unavailable in your terminal.

Original answer: Xcode - free to clear devices folder?

The easiest way to replace white spaces with (underscores) _ in bash

You can do it using only the shell, no need for tr or sed

$ str="This is just a test"
$ echo ${str// /_}
This_is_just_a_test

Measuring function execution time in R

The package "tictoc" gives you a very simple way of measuring execution time. The documentation is in: https://cran.fhcrc.org/web/packages/tictoc/tictoc.pdf.

install.packages("tictoc")
require(tictoc)
tic()
rnorm(1000,0,1)
toc()

To save the elapsed time into a variable you can do:

install.packages("tictoc")
require(tictoc)
tic()
rnorm(1000,0,1)
exectime <- toc()
exectime <- exectime$toc - exectime$tic

passing 2 $index values within nested ng-repeat

Just to help someone who get here... You should not use $parent.$index as it's not really safe. If you add an ng-if inside the loop, you get the $index messed!

Right way

  <table>
    <tr ng-repeat="row in rows track by $index" ng-init="rowIndex = $index">
        <td ng-repeat="column in columns track by $index" ng-init="columnIndex = $index">

          <b ng-if="rowIndex == columnIndex">[{{rowIndex}} - {{columnIndex}}]</b>
          <small ng-if="rowIndex != columnIndex">[{{rowIndex}} - {{columnIndex}}]</small>

        </td>
    </tr>
  </table>

Check: plnkr.co/52oIhLfeXXI9ZAynTuAJ

PHP Pass by reference in foreach

This question has a lot of explanations provided, but no clear examples of how to solve the problem that this behavior causes. In most cases, you'll probably want the following code in your pass by reference foreach.

foreach ($array as &$row) {
    // Do stuff
}
// Unset to remove the reference
unset($row);

Align Div at bottom on main Div

This isn't really possible in HTML unless you use absolute positioning or javascript. So one solution would be to give this CSS to #bottom_link:

#bottom_link {
    position:absolute;
    bottom:0;
}

Otherwise you'd have to use some javascript. Here's a jQuery block that should do the trick, depending on the simplicity of the page.

$('#bottom_link').css({
    position: 'relative',
    top: $(this).parent().height() - $(this).height()
});

Programmatically go back to previous ViewController in Swift

Swift 3:

If you want to go back to the previous view controller

_ = navigationController?.popViewController(animated: true)

If you want to go back to the root view controller

_ = navigationController?.popToRootViewController(animated: true)

Get custom product attributes in Woocommerce

woocommerce_get_product_terms() is now deprecated.

Use wc_get_product_terms() instead.

Example:

global $product;
$koostis = array_shift( wc_get_product_terms( $product->id, 'pa_koostis', array( 'fields' => 'names' ) ) );

how to delete installed library form react native project

you have to check your linked project, in the new version of RN, don't need to link if you linked it cause a problem, I Fixed the problem by unlinked manually the dependency that I linked and re-run.

Execution order of events when pressing PrimeFaces p:commandButton

It failed because you used ajax="false". This fires a full synchronous request which in turn causes a full page reload, causing the oncomplete to be never fired (note that all other ajax-related attributes like process, onstart, onsuccess, onerror and update are also never fired).

That it worked when you removed actionListener is also impossible. It should have failed the same way. Perhaps you also removed ajax="false" along it without actually understanding what you were doing. Removing ajax="false" should indeed achieve the desired requirement.


Also is it possible to execute actionlistener and oncomplete simultaneously?

No. The script can only be fired before or after the action listener. You can use onclick to fire the script at the moment of the click. You can use onstart to fire the script at the moment the ajax request is about to be sent. But they will never exactly simultaneously be fired. The sequence is as follows:

  • User clicks button in client
  • onclick JavaScript code is executed
  • JavaScript prepares ajax request based on process and current HTML DOM tree
  • onstart JavaScript code is executed
  • JavaScript sends ajax request from client to server
  • JSF retrieves ajax request
  • JSF processes the request lifecycle on JSF component tree based on process
  • actionListener JSF backing bean method is executed
  • action JSF backing bean method is executed
  • JSF prepares ajax response based on update and current JSF component tree
  • JSF sends ajax response from server to client
  • JavaScript retrieves ajax response
    • if HTTP response status is 200, onsuccess JavaScript code is executed
    • else if HTTP response status is 500, onerror JavaScript code is executed
  • JavaScript performs update based on ajax response and current HTML DOM tree
  • oncomplete JavaScript code is executed

Note that the update is performed after actionListener, so if you were using onclick or onstart to show the dialog, then it may still show old content instead of updated content, which is poor for user experience. You'd then better use oncomplete instead to show the dialog. Also note that you'd better use action instead of actionListener when you intend to execute a business action.

See also:

Submit form using AJAX and jQuery

First give your form an id attribute, then use code like this:

$(document).ready( function() {
  var form = $('#my_awesome_form');

  form.find('select:first').change( function() {
    $.ajax( {
      type: "POST",
      url: form.attr( 'action' ),
      data: form.serialize(),
      success: function( response ) {
        console.log( response );
      }
    } );
  } );

} );

So this code uses .serialize() to pull out the relevant data from the form. It also assumes the select you care about is the first one in the form.

For future reference, the jQuery docs are very, very good.

Extract source code from .jar file

Steps to get sources of a jar file as a zip :

  1. Download JD-GUI from http://java-decompiler.github.io/ and save it at any location on your system.

  2. Drag and drop the jar or open .jar file for which you want the sources on the JD.

  3. Java Decompiler will open with all the package structure in a tree format.

  4. Click on File menu and select save jar sources. It will save the sources as a zip with the same name as the jar.

Example:-

enter image description here

We can use Eclipse IDE for Java EE Developers as well for update/extract code if require.

From eclipse chose Import Jar and then select jar which you need. Follow instruction as per image below

enter image description here

enter image description here

What does -> mean in Python function definitions?

This means the type of result the function returns, but it can be None.

It is widespread in modern libraries oriented on Python 3.x.

For example, it there is in code of library pandas-profiling in many places for example:

def get_description(self) -> dict:

def get_rejected_variables(self, threshold: float = 0.9) -> list:

def to_file(self, output_file: Path or str, silent: bool = True) -> None:
"""Write the report to a file.

Make new column in Panda dataframe by adding values from other columns

You can solve it by adding simply: df['C'] = df['A'] + df['B']

error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)' -- Missing /var/run/mysqld/mysqld.sock

I would also check the mysql configuration. I was running into this problem with my own server but I was a bit too hasty and misconfigured the innodb_buffer_pool_size for my machine.

innodb_buffer_pool_size = 4096M

It usually runs fine up to 2048 but I guess I don't have the memory necessary to support 4 gigs.

I imagine this could also happen with other mysql configuration settings.

Get Multiple Values in SQL Server Cursor

Do not use @@fetch_status - this will return status from the last cursor in the current connection. Use the example below:

declare @sqCur cursor;
declare @data varchar(1000);
declare @i int = 0, @lastNum int, @rowNum int;
set @sqCur = cursor local static read_only for 
    select
         row_number() over (order by(select null)) as RowNum
        ,Data -- you fields
    from YourIntTable
open @cur
begin try
    fetch last from @cur into @lastNum, @data
    fetch absolute 1 from @cur into @rowNum, @data --start from the beginning and get first value 
    while @i < @lastNum
    begin
        set @i += 1

        --Do your job here
        print @data

        fetch next from @cur into @rowNum, @data
    end
end try
begin catch
    close @cur      --|
    deallocate @cur --|-remove this 3 lines if you do not throw
    ;throw          --|
end catch
close @cur
deallocate @cur

Programmatically saving image to Django ImageField

Another possible way to do that:

from django.core.files import File

with open('path_to_file', 'r') as f:   # use 'rb' mode for python3
    data = File(f)
    model.image.save('filename', data, True)

How to run a shell script on a Unix console or Mac terminal?

First, give permission for execution:-
chmod +x script_name

  1. If script is not executable:-
    For running sh script file:-
    sh script_name
    For running bash script file:-
    bash script_name
  2. If script is executable:-
    ./script_name

NOTE:-you can check if the file is executable or not by using 'ls -a'

Laravel 5 - redirect to HTTPS

In Laravel 5.1, I used: File: app\Providers\AppServiceProvider.php

public function boot()
{
    if ($this->isSecure()) {
        \URL::forceSchema('https');
    }
}

public function isSecure()
{
    $isSecure = false;
    if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') {
        $isSecure = true;
    } elseif (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https' || !empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] == 'on') {
        $isSecure = true;
    }

    return $isSecure;
}

NOTE: use forceSchema, NOT forceScheme

In C#, why is String a reference type that behaves like a value type?

It is mainly a performance issue.

Having strings behave LIKE value type helps when writing code, but having it BE a value type would make a huge performance hit.

For an in-depth look, take a peek at a nice article on strings in the .net framework.

PHP sessions that have already been started

Try

<?php
    if(!isset($_SESSION)) 
    { 
        session_start(); 
    } 
?>

The entity type <type> is not part of the model for the current context

if you are trying DB first then be sure that your table has primary key

How do I handle the window close event in Tkinter?

I'd like to thank the answer by Apostolos for bringing this to my attention. Here's a much more detailed example for Python 3 in the year 2019, with a clearer description and example code.


Beware of the fact that destroy() (or not having a custom window closing handler at all) will destroy the window and all of its running callbacks instantly when the user closes it.

This can be bad for you, depending on your current Tkinter activity, and especially when using tkinter.after (periodic callbacks). You might be using a callback which processes some data and writes to disk... in that case, you obviously want the data writing to finish without being abruptly killed.

The best solution for that is to use a flag. So when the user requests window closing, you mark that as a flag, and then react to it.

(Note: I normally design GUIs as nicely encapsulated classes and separate worker threads, and I definitely don't use "global" (I use class instance variables instead), but this is meant to be a simple, stripped-down example to demonstrate how Tk abruptly kills your periodic callbacks when the user closes the window...)

from tkinter import *
import time

# Try setting this to False and look at the printed numbers (1 to 10)
# during the work-loop, if you close the window while the periodic_call
# worker is busy working (printing). It will abruptly end the numbers,
# and kill the periodic callback! That's why you should design most
# applications with a safe closing callback as described in this demo.
safe_closing = True

# ---------

busy_processing = False
close_requested = False

def close_window():
    global close_requested
    close_requested = True
    print("User requested close at:", time.time(), "Was busy processing:", busy_processing)

root = Tk()
if safe_closing:
    root.protocol("WM_DELETE_WINDOW", close_window)
lbl = Label(root)
lbl.pack()

def periodic_call():
    global busy_processing

    if not close_requested:
        busy_processing = True
        for i in range(10):
            print((i+1), "of 10")
            time.sleep(0.2)
            lbl["text"] = str(time.time()) # Will error if force-closed.
            root.update() # Force redrawing since we change label multiple times in a row.
        busy_processing = False
        root.after(500, periodic_call)
    else:
        print("Destroying GUI at:", time.time())
        try: # "destroy()" can throw, so you should wrap it like this.
            root.destroy()
        except:
            # NOTE: In most code, you'll wanna force a close here via
            # "exit" if the window failed to destroy. Just ensure that
            # you have no code after your `mainloop()` call (at the
            # bottom of this file), since the exit call will cause the
            # process to terminate immediately without running any more
            # code. Of course, you should NEVER have code after your
            # `mainloop()` call in well-designed code anyway...
            # exit(0)
            pass

root.after_idle(periodic_call)
root.mainloop()

This code will show you that the WM_DELETE_WINDOW handler runs even while our custom periodic_call() is busy in the middle of work/loops!

We use some pretty exaggerated .after() values: 500 milliseconds. This is just meant to make it very easy for you to see the difference between closing while the periodic call is busy, or not... If you close while the numbers are updating, you will see that the WM_DELETE_WINDOW happened while your periodic call "was busy processing: True". If you close while the numbers are paused (meaning that the periodic callback isn't processing at that moment), you see that the close happened while it's "not busy".

In real-world usage, your .after() would use something like 30-100 milliseconds, to have a responsive GUI. This is just a demonstration to help you understand how to protect yourself against Tk's default "instantly interrupt all work when closing" behavior.

In summary: Make the WM_DELETE_WINDOW handler set a flag, and then check that flag periodically and manually .destroy() the window when it's safe (when your app is done with all work).

PS: You can also use WM_DELETE_WINDOW to ask the user if they REALLY want to close the window; and if they answer no, you don't set the flag. It's very simple. You just show a messagebox in your WM_DELETE_WINDOW and set the flag based on the user's answer.

How to hide columns in HTML table?

You can use the nth-child CSS selector to hide a whole column:

#myTable tr > *:nth-child(2) {
    display: none;
}

This works under assumption that a cell of column N (be it a th or td) is always the Nth child element of its row.

Here's a demo.


? If you want the column number to be dynamic, you could do that using querySelectorAll or any framework presenting similar functionality, like jQuery here:

$('#myTable tr > *:nth-child(2)').hide();

Demo with jQuery

(The jQuery solution also works on legacy browsers that don't support nth-child).

Counting the number of elements in array

This expands on the answer by Denis Bubnov.

I used this to find child values of array elements—namely if there was a anchor field in paragraphs on a Drupal 8 site to build a table of contents.

{% set count = 0 %}
{% for anchor in items %}
    {% if anchor.content['#paragraph'].field_anchor_link.0.value %}
        {% set count = count + 1 %}
    {% endif %}
{% endfor %}

{% if count > 0 %}
 ---  build the toc here --
{% endif %}

What's the difference between `raw_input()` and `input()` in Python 3?

In Python 2, raw_input() returns a string, and input() tries to run the input as a Python expression.

Since getting a string was almost always what you wanted, Python 3 does that with input(). As Sven says, if you ever want the old behaviour, eval(input()) works.

What does "while True" mean in Python?

In this context, I suppose it could be interpreted as

do
...
while cmd  != 'e' 

Click events on Pie Charts in Chart.js

Update: As @Soham Shetty comments, getSegmentsAtEvent(event) only works for 1.x and for 2.x getElementsAtEvent should be used.

.getElementsAtEvent(e)

Looks for the element under the event point, then returns all elements at the same data index. This is used internally for 'label' mode highlighting.

Calling getElementsAtEvent(event) on your Chart instance passing an argument of an event, or jQuery event, will return the point elements that are at that the same position of that event.

canvas.onclick = function(evt){
    var activePoints = myLineChart.getElementsAtEvent(evt);
    // => activePoints is an array of points on the canvas that are at the same position as the click event.
};

Example: https://jsfiddle.net/u1szh96g/208/


Original answer (valid for Chart.js 1.x version):

You can achieve this using getSegmentsAtEvent(event)

Calling getSegmentsAtEvent(event) on your Chart instance passing an argument of an event, or jQuery event, will return the segment elements that are at that the same position of that event.

From: Prototype Methods

So you can do:

$("#myChart").click( 
    function(evt){
        var activePoints = myNewChart.getSegmentsAtEvent(evt);           
        /* do something */
    }
);  

Here is a full working example:

<html>
    <head>
        <script type="text/javascript" src="http://code.jquery.com/jquery-2.0.2.js"></script>
        <script type="text/javascript" src="Chart.js"></script>
        <script type="text/javascript">
            var data = [
                {
                    value: 300,
                    color:"#F7464A",
                    highlight: "#FF5A5E",
                    label: "Red"
                },
                {
                    value: 50,
                    color: "#46BFBD",
                    highlight: "#5AD3D1",
                    label: "Green"
                },
                {
                    value: 100,
                    color: "#FDB45C",
                    highlight: "#FFC870",
                    label: "Yellow"
                }
            ];

            $(document).ready( 
                function () {
                    var ctx = document.getElementById("myChart").getContext("2d");
                    var myNewChart = new Chart(ctx).Pie(data);

                    $("#myChart").click( 
                        function(evt){
                            var activePoints = myNewChart.getSegmentsAtEvent(evt);
                            var url = "http://example.com/?label=" + activePoints[0].label + "&value=" + activePoints[0].value;
                            alert(url);
                        }
                    );                  
                }
            );
        </script>
    </head>
    <body>
        <canvas id="myChart" width="400" height="400"></canvas>
    </body>
</html>

Free space in a CMD shell

If you run "dir c:\", the last line will give you the free disk space.

Edit: Better solution: "fsutil volume diskfree c:"

How to create an exit message

I've never heard of such a function, but it would be trivial enough to implement...

def die(msg)
  puts msg
  exit
end

Then, if this is defined in some .rb file that you include in all your scripts, you are golden.... just because it's not built in doesn't mean you can't do it yourself ;-)

WSDL/SOAP Test With soapui

You can try opening the wsdl in web browser and saving with .wsdl extension. And set the WSDL in SOAP UI project to this .wsdl file. This really works.

"Invalid JSON primitive" in Ajax processing

Using

data : JSON.stringify(obj)

in the above situation would have worked I believe.

Note: You should add json2.js library all browsers don't support that JSON object (IE7-) Difference between json.js and json2.js

Passing variable from Form to Module in VBA

Don't declare the variable in the userform. Declare it as Public in the module.

Public pass As String

In the Userform

Private Sub CommandButton1_Click()
    pass = UserForm1.TextBox1
    Unload UserForm1
End Sub

In the Module

Public pass As String

Public Sub Login()
    '
    '~~> Rest of the code
    '
    UserForm1.Show
    driver.findElementByName("PASSWORD").SendKeys pass
    '
    '~~> Rest of the code
    '
End Sub

You might want to also add an additional check just before calling the driver.find... line?

If Len(Trim(pass)) <> 0 Then

This will ensure that a blank string is not passed.

Unity 2d jumping script

Usually for jumping people use Rigidbody2D.AddForce with Forcemode.Impulse. It may seem like your object is pushed once in Y axis and it will fall down automatically due to gravity.

Example:

rigidbody2D.AddForce(new Vector2(0, 10), ForceMode2D.Impulse);

Error:(1, 0) Plugin with id 'com.android.application' not found

If you work on Windows , you must start Android Studio name by Administrator. It solved my problem

How do I get the time of day in javascript/Node.js?

There's native method to work with date

const date = new Date();
let hours = date.getHours();

How do I overload the [] operator in C#

public int this[int index]
{
    get => values[index];
}

How do I retrieve my MySQL username and password?

If you have root access to the server where mysql is running you should stop the mysql server using this command

sudo service mysql stop

Now start mysql using this command

sudo /usr/sbin/mysqld --skip-grant-tables  --skip-networking &

Now you can login to mysql using

sudo mysql
FLUSH PRIVILEGES;
SET PASSWORD FOR 'root'@'localhost' = PASSWORD('MyNewPass');

Full instructions can be found here http://www.techmatterz.com/recover-mysql-root-password/

How can I execute PHP code from the command line?

You can use:

 echo '<?php if(function_exists("my_func")) echo "function exists"; ' | php

The short tag "< ?=" can be helpful too:

 echo '<?= function_exists("foo") ? "yes" : "no";' | php
 echo '<?= 8+7+9 ;' | php

The closing tag "?>" is optional, but don't forget the final ";"!

nodejs vs node on ubuntu 12.04

Late answer, but for up-to-date info...

If you install node.js using the recommend method from the node github installation readme, it suggests following the instructions on the nodesource blog article, rather than installing from the out of date apt-get repo, node.js should run using the node command, as well as the nodejs command, without having to make a new symlink.

This method from article is:

# Note the new setup script name for Node.js v0.12
curl -sL https://deb.nodesource.com/setup_0.12 | sudo bash -

# Then install with:
sudo apt-get install -y nodejs

Note that this is for v0.12, which will get likely become outdated in the not to distant future.

Also, if you're behind a corporate proxy (like me) you'll want to add the -E option to the sudo command, to preserve the env vars required for the proxy:

curl -sL https://deb.nodesource.com/setup_0.12 | sudo -E bash -

Angular2 Material Dialog css, dialog size

With current version of Angular Material (6.4.7) you can use a custom class:

let dialogRef = dialog.open(UserProfileComponent, {
  panelClass: 'my-class'
});

Now put your class somewhere global (haven't been able to make this work elsewhere), e.g. in styles.css:

.my-class .mat-dialog-container{
  height: 400px;
  width: 600px;
  border-radius: 10px;
  background: lightcyan;
  color: #039be5;
}

Done!

How do I check if an HTML element is empty using jQuery?

White space and line breaks are the main issues with using :empty selector. Careful, in CSS the :empty pseudo class behaves the same way. I like this method:

if ($someElement.children().length == 0){
     someAction();
}

Replace all whitespace with a line break/paragraph mark to make a word list

For reasonably modern versions of sed, edit the standard input to yield the standard output with

$ echo 't???? ß?ß??? ?? ??p??' | sed -E -e 's/[[:blank:]]+/\n/g'
t????
ß?ß???
??
??p??

If your vocabulary words are in files named lesson1 and lesson2, redirect sed’s standard output to the file all-vocab with

sed -E -e 's/[[:blank:]]+/\n/g' lesson1 lesson2 > all-vocab

What it means:

  • The character class [[:blank:]] matches either a single space character or a single tab character.
    • Use [[:space:]] instead to match any single whitespace character (commonly space, tab, newline, carriage return, form-feed, and vertical tab).
    • The + quantifier means match one or more of the previous pattern.
    • So [[:blank:]]+ is a sequence of one or more characters that are all space or tab.
  • The \n in the replacement is the newline that you want.
  • The /g modifier on the end means perform the substitution as many times as possible rather than just once.
  • The -E option tells sed to use POSIX extended regex syntax and in particular for this case the + quantifier. Without -E, your sed command becomes sed -e 's/[[:blank:]]\+/\n/g'. (Note the use of \+ rather than simple +.)

Perl Compatible Regexes

For those familiar with Perl-compatible regexes and a PCRE-capable sed, use \s+ to match runs of at least one whitespace character, as in

sed -E -e 's/\s+/\n/g' old > new

or

sed -e 's/\s\+/\n/g' old > new

These commands read input from the file old and write the result to a file named new in the current directory.

Maximum portability, maximum cruftiness

Going back to almost any version of sed since Version 7 Unix, the command invocation is a bit more baroque.

$ echo 't???? ß?ß??? ?? ??p??' | sed -e 's/[ \t][ \t]*/\
/g'
t????
ß?ß???
??
??p??

Notes:

  • Here we do not even assume the existence of the humble + quantifier and simulate it with a single space-or-tab ([ \t]) followed by zero or more of them ([ \t]*).
  • Similarly, assuming sed does not understand \n for newline, we have to include it on the command line verbatim.
    • The \ and the end of the first line of the command is a continuation marker that escapes the immediately following newline, and the remainder of the command is on the next line.
      • Note: There must be no whitespace preceding the escaped newline. That is, the end of the first line must be exactly backslash followed by end-of-line.
    • This error prone process helps one appreciate why the world moved to visible characters, and you will want to exercise some care in trying out the command with copy-and-paste.

Note on backslashes and quoting

The commands above all used single quotes ('') rather than double quotes (""). Consider:

$ echo '\\\\' "\\\\"
\\\\ \\

That is, the shell applies different escaping rules to single-quoted strings as compared with double-quoted strings. You typically want to protect all the backslashes common in regexes with single quotes.

Colorized grep -- viewing the entire file with highlighted matches

Here is a shell script that uses Awk's gsub function to replace the text you're searching for with the proper escape sequence to display it in bright red:

#! /bin/bash
awk -vstr=$1 'BEGIN{repltext=sprintf("%c[1;31;40m&%c[0m", 0x1B,0x1B);}{gsub(str,repltext); print}' $2

Use it like so:

$ ./cgrep pattern [file]

Unfortunately, it doesn't have all the functionality of grep.

For more information , you can refer to an article "So You Like Color" in Linux Journal

Add Keypair to existing EC2 instance

This happened to me earlier (didn't have access to an EC2 instance someone else created but had access to AWS web console) and I blogged the answer: http://readystate4.com/2013/04/09/aws-gaining-ssh-access-to-an-ec2-instance-you-lost-access-to/

Basically, you can detached the EBS drive, attach it to an EC2 that you do have access to. Add your SSH pub key to ~ec2-user/.ssh/authorized_keys on this attached drive. Then put it back on the old EC2 instance. step-by-step in the link using Amazon AMI.

No need to make snapshots or create a new cloned instance.

Java Regex Capturing Groups

Your understanding is correct. However, if we walk through:

  • (.*) will swallow the whole string;
  • it will need to give back characters so that (\\d+) is satistifed (which is why 0 is captured, and not 3000);
  • the last (.*) will then capture the rest.

I am not sure what the original intent of the author was, however.

Special characters like @ and & in cURL POST data

How about using the entity codes...

@ = %40

& = %26

So, you would have:

curl -d 'name=john&passwd=%4031%263*J' https://www.mysite.com

how to output every line in a file python

Loop through the file.

f = open("masters.txt")
lines = f.readlines()
for line in lines:
    print line

oracle - what statements need to be committed?

DML have to be committed or rollbacked. DDL cannot.

http://www.orafaq.com/faq/what_are_the_difference_between_ddl_dml_and_dcl_commands

You can switch auto-commit on and that's again only for DML. DDL are never part of transactions and therefore there is nothing like an explicit commit/rollback.

truncate is DDL and therefore commited implicitly.

Edit
I've to say sorry. Like @DCookie and @APC stated in the comments there exist sth like implicit commits for DDL. See here for a question about that on Ask Tom. This is in contrast to what I've learned and I am still a bit curious about.

Removing header column from pandas dataframe

Haven't seen this solution yet so here's how I did it without using read_csv:

df.rename(columns={'A':'','B':''})

If you rename all your column names to empty strings your table will return without a header.

And if you have a lot of columns in your table you can just create a dictionary first instead of renaming manually:

df_dict = dict.fromkeys(df.columns, '')
df.rename(columns = df_dict)

Disable Input fields in reactive form

while making ReactiveForm:[define properety disbaled in FormControl]

 'fieldName'= new FormControl({value:null,disabled:true})

html:

 <input type="text" aria-label="billNo" class="form-control" formControlName='fieldName'>

How to print an exception in Python 3?

These are the changes since python 2:

    try:
        1 / 0
    except Exception as e: # (as opposed to except Exception, e:)
                           # ^ that will just look for two classes, Exception and e
        # for the repr
        print(repr(e))
        # for just the message, or str(e), since print calls str under the hood
        print(e)
        # the arguments that the exception has been called with. 
        # the first one is usually the message. (OSError is different, though)
        print(e.args)

You can look into the standard library module traceback for fancier stuff.

How do I change a single value in a data.frame?

In RStudio you can write directly in a cell. Suppose your data.frame is called myDataFrame and the row and column are called columnName and rowName. Then the code would look like:

myDataFrame["rowName", "columnName"] <- value

Hope that helps!

Google Recaptcha v3 example demo

Simple code to implement ReCaptcha v3

The basic JS code

<script src="https://www.google.com/recaptcha/api.js?render=your reCAPTCHA site key here"></script>
<script>
    grecaptcha.ready(function() {
    // do request for recaptcha token
    // response is promise with passed token
        grecaptcha.execute('your reCAPTCHA site key here', {action:'validate_captcha'})
                  .then(function(token) {
            // add token value to form
            document.getElementById('g-recaptcha-response').value = token;
        });
    });
</script>

The basic HTML code

<form id="form_id" method="post" action="your_action.php">
    <input type="hidden" id="g-recaptcha-response" name="g-recaptcha-response">
    <input type="hidden" name="action" value="validate_captcha">
    .... your fields
</form>

The basic PHP code

if (isset($_POST['g-recaptcha-response'])) {
    $captcha = $_POST['g-recaptcha-response'];
} else {
    $captcha = false;
}

if (!$captcha) {
    //Do something with error
} else {
    $secret   = 'Your secret key here';
    $response = file_get_contents(
        "https://www.google.com/recaptcha/api/siteverify?secret=" . $secret . "&response=" . $captcha . "&remoteip=" . $_SERVER['REMOTE_ADDR']
    );
    // use json_decode to extract json response
    $response = json_decode($response);

    if ($response->success === false) {
        //Do something with error
    }
}

//... The Captcha is valid you can continue with the rest of your code
//... Add code to filter access using $response . score
if ($response->success==true && $response->score <= 0.5) {
    //Do something to denied access
}

You have to filter access using the value of $response.score. It can takes values from 0.0 to 1.0, where 1.0 means the best user interaction with your site and 0.0 the worst interaction (like a bot). You can see some examples of use in ReCaptcha documentation.

How do I measure separate CPU core usage for a process?

The ps solution was nearly what I needed and with some bash thrown in does exactly what the original question asked for: to see per-core usage of specific processes

This shows per-core usage of multi-threaded processes too.

Use like: cpustat `pgrep processname` `pgrep otherprocessname` ...

#!/bin/bash

pids=()
while [ $# != 0 ]; do
        pids=("${pids[@]}" "$1")
        shift
done

if [ -z "${pids[0]}" ]; then
        echo "Usage: $0 <pid1> [pid2] ..."
        exit 1
fi

for pid in "${pids[@]}"; do
        if [ ! -e /proc/$pid ]; then
                echo "Error: pid $pid doesn't exist"
                exit 1
        fi
done

while [ true ]; do
        echo -e "\033[H\033[J"
        for pid in "${pids[@]}"; do
                ps -p $pid -L -o pid,tid,psr,pcpu,comm=
        done
        sleep 1
done

Note: These stats are based on process lifetime, not the last X seconds, so you'll need to restart your process to reset the counter.

Determine the process pid listening on a certain port

The -p flag of netstat gives you PID of the process:

netstat -l -p

Edit: The command that is needed to get PIDs of socket users in FreeBSD is sockstat. As we worked out during the discussion with @Cyclone, the line that does the job is:

sockstat -4 -l | grep :80 | awk '{print $3}' | head -1

Why boolean in Java takes only true or false? Why not 1 or 0 also?

Because the people who created Java wanted boolean to mean unambiguously true or false, not 1 or 0.

There's no consensus among languages about how 1 and 0 convert to booleans. C uses any nonzero value to mean true and 0 to mean false, but some UNIX shells do the opposite. Using ints weakens type-checking, because the compiler can't guard against cases where the int value passed in isn't something that should be used in a boolean context.

sudo: docker-compose: command not found

On Ubuntu 16.04

Here's how I fixed this issue: Refer Docker Compose documentation

  1. sudo curl -L https://github.com/docker/compose/releases/download/1.21.0/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose

  2. sudo chmod +x /usr/local/bin/docker-compose

After you do the curl command , it'll put docker-compose into the

/usr/local/bin

which is not on the PATH. To fix it, create a symbolic link:

  1. sudo ln -s /usr/local/bin/docker-compose /usr/bin/docker-compose

And now if you do: docker-compose --version

You'll see that docker-compose is now on the PATH

Convert string to float?

String s = "3.14";
float f = Float.parseFloat(s);

google map API zoom range

Available Zoom Levels

Zoom level 0 is the most zoomed out zoom level available and each integer step in zoom level halves the X and Y extents of the view and doubles the linear resolution.

Google Maps was built on a 256x256 pixel tile system where zoom level 0 was a 256x256 pixel image of the whole earth. A 256x256 tile for zoom level 1 enlarges a 128x128 pixel region from zoom level 0.

As correctly stated by bkaid, the available zoom range depends on where you are looking and the kind of map you are using:

  • Road maps - seem to go up to zoom level 22 everywhere
  • Hybrid and satellite maps - the max available zoom levels depend on location. Here are some examples:
  • Remote regions of Antarctica: 13
  • Gobi Desert: 17
  • Much of the U.S. and Europe: 21
  • "Deep zoom" locations: 22-23 (see bkaid's link)

Note that these values are for the Google Static Maps API which seems to give one more zoom level than the Javascript API. It appears that the extra zoom level available for Static Maps is just an upsampled version of the max-resolution image from the Javascript API.

Map Scale at Various Zoom Levels

Google Maps uses a Mercator projection so the scale varies substantially with latitude. A formula for calculating the correct scale based on latitude is:

meters_per_pixel = 156543.03392 * Math.cos(latLng.lat() * Math.PI / 180) / Math.pow(2, zoom)

Formula is from Chris Broadfoot's comment.


Google Maps basics

Zoom Level - zoom

0 - 19

0 lowest zoom (whole world)

19 highest zoom (individual buildings, if available) Retrieve current zoom level using mapObject.getZoom()


What you're looking for are the scales for each zoom level. Use these:

20 : 1128.497220
19 : 2256.994440
18 : 4513.988880
17 : 9027.977761
16 : 18055.955520
15 : 36111.911040
14 : 72223.822090
13 : 144447.644200
12 : 288895.288400
11 : 577790.576700
10 : 1155581.153000
9  : 2311162.307000
8  : 4622324.614000
7  : 9244649.227000
6  : 18489298.450000
5  : 36978596.910000
4  : 73957193.820000
3  : 147914387.600000
2  : 295828775.300000
1  : 591657550.500000

Using SED with wildcard

The asterisk (*) means "zero or more of the previous item".

If you want to match any single character use

sed -i 's/string-./string-0/g' file.txt

If you want to match any string (i.e. any single character zero or more times) use

sed -i 's/string-.*/string-0/g' file.txt

.htaccess redirect all pages to new domain

May be like this:

Options +FollowSymLinks
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^OLDDOMAIN\.com$ [NC]
RewriteRule ^(.*)$ http://NEWDOMAIN.com [R=301,L]

How to break line in JavaScript?

Add %0D%0A to any place you want to encode a line break on the URL.

  • %0D is a carriage return character
  • %0A is a line break character

This is the new line sequence on windows machines, though not the same on linux and macs, should work in both.

If you want a linebreak in actual javascript, use the \n escape sequence.


onClick="parent.location='mailto:[email protected]?subject=Thanks for writing to me &body=I will get back to you soon.%0D%0AThanks and Regards%0D%0ASaurav Kumar'

What is the difference between Cygwin and MinGW?

Don't overlook AT&T's U/Win software, which is designed to help you compile Unix applications on windows (last version - 2012-08-06; uses Eclipse Public License, Version 1.0).

Like Cygwin they have to run against a library; in their case POSIX.DLL. The AT&T guys are terrific engineers (same group that brought you ksh and dot) and their stuff is worth checking out.

Center Align on a Absolutely Positioned Div

Yes:

div#thing { text-align:center; }

Getting current directory in VBScript

Use With in the code.

Try this way :

''''Way 1

currentdir=Left(WScript.ScriptFullName,InStrRev(WScript.ScriptFullName,"\"))


''''Way 2

With CreateObject("WScript.Shell")
CurrentPath=.CurrentDirectory
End With


''''Way 3

With WSH
CD=Replace(.ScriptFullName,.ScriptName,"")
End With

Processing $http response in service

Related to this I went through a similar problem, but not with get or post made by Angular but with an extension made by a 3rd party (in my case Chrome Extension).
The problem that I faced is that the Chrome Extension won't return then() so I was unable to do it the way in the solution above but the result is still Asynchronous.
So my solution is to create a service and to proceed to a callback

app.service('cookieInfoService', function() {
    this.getInfo = function(callback) {
        var model = {};
        chrome.cookies.get({url:serverUrl, name:'userId'}, function (response) {
            model.response= response;
            callback(model);
        });
    };
});

Then in my controller

app.controller("MyCtrl", function ($scope, cookieInfoService) {
    cookieInfoService.getInfo(function (info) {
        console.log(info);
    });
});

Hope this can help others getting the same issue.

How do I change the android actionbar title and icon

In Android 5.0 material design guidelines discourage the use of icon in actionBar

to enable it add the following code

getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setLogo(R.mipmap.ic_launcher);
getSupportActionBar().setDisplayUseLogoEnabled(true);

credit goes to author of this article

App installation failed due to application-identifier entitlement

I found that I had accidentally changed the provisioning profile to have a wildcard in it.

Ie., it went from com.companyname.appnickname to com.companyname.*

I made a new provisioning profile with the full name correctly named, downloaded it, set the Target->build settings->provisioning profile to that new profile, restarted xcode, got a bizarre error from xcode (it seemed to confuse my various app developer logins), restarted xcode again, and it worked!

I didn't want to delete the existing app, because I was trying to test what happens when a user upgraded their app to a newer version, so I had installed the app store version and then run my xcode with the newer version (which acts like 'upgrading' the app without removing any user data).

The type java.lang.CharSequence cannot be resolved in package declaration

Make your Project and Workspace to point to JDK7 which will resolve the issue. https://developers.google.com/eclipse/docs/jdk_compliance has given ways to modify Compliance and Facet level changes.

Check whether an array is empty

You can also check it by doing.

if(count($array) > 0)
{
    echo 'Error';
}
else
{
    echo 'No Error';
}

Extracting Ajax return data in jQuery

I have noticed that your success function has the parameter "html", and you are trying to add "data" to your elements html()... Change it so these both match:

$.ajax({
    type:"POST",
    url: "ajax.php",
    data:"id="+id ,
    success: function(data){
        $("#response").html(data);
    }
});

Sorting a list using Lambda/Linq to objects

You could use Reflection to get the value of the property.

list = list.OrderBy( x => TypeHelper.GetPropertyValue( x, sortBy ) )
           .ToList();

Where TypeHelper has a static method like:

public static class TypeHelper
{
    public static object GetPropertyValue( object obj, string name )
    {
        return obj == null ? null : obj.GetType()
                                       .GetProperty( name )
                                       .GetValue( obj, null );
    }
}

You might also want to look at Dynamic LINQ from the VS2008 Samples library. You could use the IEnumerable extension to cast the List as an IQueryable and then use the Dynamic link OrderBy extension.

 list = list.AsQueryable().OrderBy( sortBy + " " + sortDirection );

What's the best CRLF (carriage return, line feed) handling strategy with Git?

You almost always want autocrlf=input unless you really know what you are doing.

Some additional context below:

It should be either core.autocrlf=true if you like DOS ending or core.autocrlf=input if you prefer unix-newlines. In both cases, your Git repository will have only LF, which is the Right Thing. The only argument for core.autocrlf=false was that automatic heuristic may incorrectly detect some binary as text and then your tile will be corrupted. So, core.safecrlf option was introduced to warn a user if a irreversable change happens. In fact, there are two possibilities of irreversable changes -- mixed line-ending in text file, in this normalization is desirable, so this warning can be ignored, or (very unlikely) that Git incorrectly detected your binary file as text. Then you need to use attributes to tell Git that this file is binary.

The above paragraph was originally pulled from a thread on gmane.org, but it has since gone down.

Get second child using jQuery

I didn't see it mentioned here, but you can also use CSS spec selectors. See the docs

$('#parentContainer td:nth-child(2)')

Passing route control with optional parameter after root in express?

That would work depending on what client.get does when passed undefined as its first parameter.

Something like this would be safer:

app.get('/:key?', function(req, res, next) {
    var key = req.params.key;
    if (!key) {
        next();
        return;
    }
    client.get(key, function(err, reply) {
        if(client.get(reply)) {
            res.redirect(reply);
        }
        else {
            res.render('index', {
                link: null
            });
        }
    });
});

There's no problem in calling next() inside the callback.

According to this, handlers are invoked in the order that they are added, so as long as your next route is app.get('/', ...) it will be called if there is no key.

Is it possible to use a div as content for Twitter's Popover

Building on jävi's answer, this can be done without IDs or additional button attributes like this:

http://jsfiddle.net/isherwood/E5Ly5/

<button class="popper" data-toggle="popover">Pop me</button>
<div class="popper-content hide">My first popover content goes here.</div>

<button class="popper" data-toggle="popover">Pop me</button>
<div class="popper-content hide">My second popover content goes here.</div>

<button class="popper" data-toggle="popover">Pop me</button>
<div class="popper-content hide">My third popover content goes here.</div>

$('.popper').popover({
    container: 'body',
    html: true,
    content: function () {
        return $(this).next('.popper-content').html();
    }
});

How do you cast a List of supertypes to a List of subtypes?

The only way I know is by copying:

List<TestB> list = new ArrayList<TestB> (
    Arrays.asList (
        testAList.toArray(new TestB[0])
    )
);

How can I disable selected attribute from select2() dropdown Jquery?

In selec2 site you can see options. There is "disabled" option for api. You can use like :

$('#foo').select2({
    disabled: true
});

How to grep and replace

This works best for me on OS X:

grep -r -l 'searchtext' . | sort | uniq | xargs perl -e "s/matchtext/replacetext/" -pi

Source: http://www.praj.com.au/post/23691181208/grep-replace-text-string-in-files

What is NODE_ENV and how to use it in Express?

I assume the original question included how does Express use this environment variable.

Express uses NODE_ENV to alter its own default behavior. For example, in development mode, the default error handler will send back a stacktrace to the browser. In production mode, the response is simply Internal Server Error, to avoid leaking implementation details to the world.

importing jar libraries into android-studio

If the code for your jar library is on GitHub then importing into Android Studio is easy with JitPack.

Your will just need to add the repository to build.gradle:

allprojects{
 repositories {
    jcenter()
    maven { url "https://jitpack.io" }
 }
}

and then the library's GitHub repository as a dependency:

dependencies {
    // ...
    compile 'com.github.YourUsername:LibraryRepo:ReleaseTag'
}

JitPack acts as a maven repository and can be used like Maven Central. The nice thing is that you don't have to upload the jar manually. Behind the scenes JitPack will check out the code from GitHub and compile it. Therefore it works only if the repo has a build file in it (build.gradle).

There is also a guide on how to prepare an Android project.

Append lines to a file using a StreamWriter

One more simple way is using the File.AppendText it appends UTF-8 encoded text to an existing file, or to a new file if the specified file does not exist and returns a System.IO.StreamWriter

using (System.IO.StreamWriter sw = System.IO.File.AppendText(logFilePath + "log.txt"))
{                                                
    sw.WriteLine("this is a log");
}

How to convert BigDecimal to Double in Java?

You can convert BigDecimal to double using .doubleValue(). But believe me, don't use it if you have currency manipulations. It should always be performed on BigDecimal objects directly. Precision loss in these calculations are big time problems in currency related calculations.

Whoops, looks like something went wrong. Laravel 5.0

First run command composer install

Then check for .env.example and .env files in your project folder.

.env file is your main configuration file for database and .env.example is backup file for .env file.

.env.example file will always be there but sometimes .env file can be missing. just copy the .env.example file and paste in the same project folder with filename .env .

now run php artisan key:generate command. this will generate key for your application.

Clear text area

I believe the problem is simply a spelling error when writing bbcode as bbocde:

$("#vinanghinguyen_images_bbocde").val('')

should be:

$("#vinanghinguyen_images_bbcode").val('')

How to retrieve the LoaderException property?

Another Alternative for those who are probing around and/or in interactive mode:

$Error[0].Exception.LoaderExceptions

Note: [0] grabs the most recent Error from the stack

How to remove all options from a dropdown using jQuery / JavaScript

In case .empty() doesn't work for you, which is for me

function SetDropDownToEmpty() 
{           
$('#dropdown').find('option').remove().end().append('<option value="0"></option>');
$("#dropdown").trigger("liszt:updated");          
}

$(document).ready(
SetDropDownToEmpty() ;
)

Google Maps API: open url by clicking on marker

If anyone wants to add an URL on a single marker which not require for loops, here is how it goes:

if ($('#googleMap').length) {
    var initialize = function() {
        var mapOptions = {
            zoom: 15,
            scrollwheel: false,
            center: new google.maps.LatLng(45.725788, -73.5120818),
            styles: [{
                stylers: [{
                    saturation: -100
                }]
            }]
        };
        var map = new google.maps.Map(document.getElementById("googleMap"), mapOptions);
        var marker = new google.maps.Marker({
            position: map.getCenter(),
            animation: google.maps.Animation.BOUNCE,
            icon: 'example-marker.png',
            map: map,
            url: 'https://example.com'
        });

        //Add an url to the marker
    google.maps.event.addListener(marker, 'click', function() {
        window.location.href = this.url;
    });
    }
    // Add the map initialize function to the window load function
    google.maps.event.addDomListener(window, "load", initialize);
}

SQL is null and = null

In SQL, a comparison between a null value and any other value (including another null) using a comparison operator (eg =, !=, <, etc) will result in a null, which is considered as false for the purposes of a where clause (strictly speaking, it's "not true", rather than "false", but the effect is the same).

The reasoning is that a null means "unknown", so the result of any comparison to a null is also "unknown". So you'll get no hit on rows by coding where my_column = null.

SQL provides the special syntax for testing if a column is null, via is null and is not null, which is a special condition to test for a null (or not a null).

Here's some SQL showing a variety of conditions and and their effect as per above.

create table t (x int, y int);
insert into t values (null, null), (null, 1), (1, 1);

select 'x = null' as test , x, y from t where x = null
union all
select 'x != null', x, y from t where x != null
union all
select 'not (x = null)', x, y from t where not (x = null)
union all
select 'x = y', x, y from t where x = y
union all
select 'not (x = y)', x, y from t where not (x = y);

returns only 1 row (as expected):

TEST    X   Y
x = y   1   1

See this running on SQLFiddle

Display date in dd/mm/yyyy format in vb.net

I found this catered for dates in 21st Century that could be entered as dd/mm or dd/mm/yy. It is intended to print an attendance register and asks for the meeting date to start with.

Sub Print_Register()

Dim MeetingDate, Answer

    Sheets("Register").Select
    Range("A1").Select
GetDate:
    MeetingDate = DateValue(InputBox("Enter the date of the meeting." & Chr(13) & _
    "Note Format" & Chr(13) & "Format DD/MM/YY or DD/MM", "Meeting Date", , 10000, 10000))
    If MeetingDate = "" Then GoTo TheEnd
    If MeetingDate < 36526 Then MeetingDate = MeetingDate + 36526
    Range("Current_Meeting_Date") = MeetingDate
    Answer = MsgBox("Date OK?", 3)
    If Answer = 2 Then GoTo TheEnd
    If Answer = 7 Then GoTo GetDate
    ExecuteExcel4Macro "PRINT(1,,,1,,,,,,,,2,,,TRUE,,FALSE)"
TheEnd:
End Sub

IsNothing versus Is Nothing

VB is full of things like that trying to make it both "like English" and comfortable for people who are used to languages that use () and {} a lot. And on the other side, as you already probably know, most of the time you can use () with function calls if you want to, but don't have to.

I prefer IsNothing()... but I use C and C#, so that's just what is comfortable. And I think it's more readable. But go with whatever feels more comfortable to you.

How to check the version of scipy

Using command line:

python -c "import scipy; print(scipy.__version__)"

Can there be an apostrophe in an email address?

Yes, according to RFC 3696 apostrophes are valid as long as they come before the @ symbol.

How to pass arguments to a Button command in Tkinter?

Python's ability to provide default values for function arguments gives us a way out.

def fce(x=myX, y=myY):
    myFunction(x,y)
button = Tk.Button(mainWin, text='press', command=fce)

See: http://infohost.nmt.edu/tcc/help/pubs/tkinter/web/extra-args.html

For more buttons you can create a function which returns a function:

def fce(myX, myY):
    def wrapper(x=myX, y=myY):
        pass
        pass
        pass
        return x+y
    return wrapper

button1 = Tk.Button(mainWin, text='press 1', command=fce(1,2))
button2 = Tk.Button(mainWin, text='press 2', command=fce(3,4))
button3 = Tk.Button(mainWin, text='press 3', command=fce(9,8))

Floating Point Exception C++ Why and what is it?

Since this page is the number 1 result for the google search "c++ floating point exception", I want to add another thing that can cause such a problem: use of undefined variables.

"UserWarning: Matplotlib is currently using agg, which is a non-GUI backend, so cannot show the figure." when plotting figure with pyplot on Pycharm

You can change the matplotlib using backend using the from agg to Tkinter TKAgg using command

matplotlib.use('TKAgg',warn=False, force=True)

Correct way to use Modernizr to detect IE?

Well, after doing more research on this topic I ended up using following solution for targeting IE 10+. As IE10&11 are the only browsers which support the -ms-high-contrast media query, that is a good option without any JS:

@media screen and (-ms-high-contrast: active), screen and (-ms-high-contrast: none) {  
   /* IE10+ specific styles go here */  
}

Works perfectly.

Editing the git commit message in GitHub

GitHub's instructions for doing this:

  1. On the command line, navigate to the repository that contains the commit you want to amend.
  2. Type git commit --amend and press Enter.
  3. In your text editor, edit the commit message and save the commit.
  4. Use the git push --force example-branch command to force push over the old commit.

Source: https://help.github.com/articles/changing-a-commit-message/

How to check the first character in a string in Bash or UNIX shell?

Many ways to do this. You could use wildcards in double brackets:

str="/some/directory/file"
if [[ $str == /* ]]; then echo 1; else echo 0; fi

You can use substring expansion:

if [[ ${str:0:1} == "/" ]] ; then echo 1; else echo 0; fi

Or a regex:

if [[ $str =~ ^/ ]]; then echo 1; else echo 0; fi

How to unzip a list of tuples into individual lists?

If you want a list of lists:

>>> [list(t) for t in zip(*l)]
[[1, 3, 8], [2, 4, 9]]

If a list of tuples is OK:

>>> zip(*l)
[(1, 3, 8), (2, 4, 9)]

How to get an element's top position relative to the browser's viewport?

Edit: Add some code to account for the page scrolling.

function findPos(id) {
    var node = document.getElementById(id);     
    var curtop = 0;
    var curtopscroll = 0;
    if (node.offsetParent) {
        do {
            curtop += node.offsetTop;
            curtopscroll += node.offsetParent ? node.offsetParent.scrollTop : 0;
        } while (node = node.offsetParent);

        alert(curtop - curtopscroll);
    }
}

The id argument is the id of the element whose offset you want. Adapted from a quirksmode post.

How do I show the changes which have been staged?

Think about the gitk tool also , provided with git and very useful to see the changes