Programs & Examples On #Beyondcompare

Beyond Compare is a tool used to compare files and directories.

Git Diff with Beyond Compare

The difference is in the exe being called: set it up to call bcomp.exe and it'll work fine. Configure your environment to call bcompare.exe and you'll end up with the side of the comparison taken from your revision system being empty.

How to configure Visual Studio to use Beyond Compare

I got bored of doing this every 6 months when a new version of Visual Studio comes out, or I move PCs, or a new member joins the team. So, PowerShell:

# .Synopsys
# Sets up Beyond Compare professional as Diff tool for all instances of Visual Studio on this PC
# If you don't use TFS, change the sccProvider as appropriate
[CmdLetBinding()]
param(
    $bcPath = 'C:\Program Files (x86)\Beyond Compare 3\BComp.exe',
    $sccProvider = 'TeamFoundation'
)

$ErrorActionPreference = 'stop';
$baseKey = 'REGISTRY::\HKCU\Software\Microsoft\VisualStudio\*'

function SetRegKeyProperties($keyPath, [hashtable]$keyProps){
    if(!(Test-Path $keyPath)){
        Write-Verbose "Creating $keyPath"
        # Force required here to recursively create registry path
        [void] (new-item $keyPath -Type:Directory -Force);
    }
    foreach($prop in $keyProps.GetEnumerator()){
        Set-ItemProperty -Path:$keyPath -Name:$prop.Key -Value:$prop.Value;
    }
}

$configBases = dir $baseKey | ? { $_.PSChildName -match '^\d+\.\d$' }
foreach($item in $configBases){
    Write-Host "Configuring $item"

    $diffToolsKey = Join-Path $item.PSPath "$sccProvider\SourceControl\DiffTools"
    SetRegKeyProperties (Join-path $diffToolsKey '.*\Compare') @{Command=$bcPath;Arguments='%1 %2 /title1=%6 /title2=%7'}
    SetRegKeyProperties (Join-path $diffToolsKey '.*\Merge') @{Command=$bcPath;Arguments='%1 %2 %3 %4 /title1=%6 /title2=%7 /title3=%8 /title4=%9'}
}

Works on my machine. YMMV. No warranties, no refunds. VS doesn't appear to cache the key, so takes effect immediately.

Access a JavaScript variable from PHP

The short answer is you can't.

I don't know any PHP syntax, but what I can tell you is that PHP is executed on the server and JavaScript is executed on the client (on the browser).

You're doing a $_GET, which is used to retrieve form values:

The built-in $_GET function is used to collect values in a form with method="get".

In other words, if on your page you had:

<form method="get" action="blah.php">
    <input name="test"></input>
</form>

Your $_GET call would retrieve the value in that input field.

So how to retrieve a value from JavaScript?

Well, you could stick the javascript value in a hidden form field...

<script type="text/javascript" charset="utf-8">
    var test = "tester";
    // find the 'test' input element and set its value to the above variable
    document.getElementByID("test").value = test;
</script>

... elsewhere on your page ...

<form method="get" action="blah.php">
    <input id="test" name="test" visibility="hidden"></input>
    <input type="submit" value="Click me!"></input>
</form>

Then, when the user clicks your submit button, he/she will be issuing a "GET" request to blah.php, sending along the value in 'test'.

Execute Insert command and return inserted Id in Sql

Change the query to

"INSERT INTO Mem_Basic(Mem_Na,Mem_Occ) VALUES(@na,@occ); SELECT SCOPE_IDENTITY()"

This will return the last inserted ID which you can then get with ExecuteScalar

Setting query string using Fetch GET request

Solution without external packages

to perform a GET request using the fetch api I worked on this solution that doesn't require the installation of packages.

this is an example of a call to the google's map api

// encode to scape spaces
const esc = encodeURIComponent;
const url = 'https://maps.googleapis.com/maps/api/geocode/json?';
const params = { 
    key: "asdkfñlaskdGE",
    address: "evergreen avenue",
    city: "New York"
};
// this line takes the params object and builds the query string
const query = Object.keys(params).map(k => `${esc(k)}=${esc(params[k])}`).join('&')
const res = await fetch(url+query);
const googleResponse = await res.json()

feel free to copy this code and paste it on the console to see how it works!!

the generated url is something like:

https://maps.googleapis.com/maps/api/geocode/json?key=asdkf%C3%B1laskdGE&address=evergreen%20avenue&city=New%20York

this is what I was looking before I decided to write this, enjoy :D

How to restrict UITextField to take only numbers in Swift?

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    if let numRange = string.rangeOfCharacterFromSet(NSCharacterSet.letterCharacterSet()) {
        return false
    } else {
        return true
    }
   }

ant build.xml file doesn't exist

You have invoked Ant with the verbose (-v) mode but the default buildfile build.xml does not exist. Nor have you specified any other buildfile for it to use.

I would say your Ant installation is fine.

javax.xml.bind.UnmarshalException: unexpected element. Expected elements are (none)

When you generate a JAXB model from an XML Schema, global elements that correspond to named complex types will have that metadata captured as an @XmlElementDecl annotation on a create method in the ObjectFactory class. Since you are creating the JAXBContext on just the DocumentType class this metadata isn't being processed. If you generated your JAXB model from an XML Schema then you should create the JAXBContext on the generated package name or ObjectFactory class to ensure all the necessary metadata is processed.

Example solution:

JAXBContext jaxbContext = JAXBContext.newInstance(my.generatedschema.dir.ObjectFactory.class);
DocumentType documentType = ((JAXBElement<DocumentType>) jaxbContext.createUnmarshaller().unmarshal(inputStream)).getValue();

How to use the PRINT statement to track execution as stored procedure is running?

SQL Server returns messages after a batch of statements has been executed. Normally, you'd use SQL GO to indicate the end of a batch and to retrieve the results:

PRINT '1'
GO

WAITFOR DELAY '00:00:05'

PRINT '2'
GO

WAITFOR DELAY '00:00:05'

PRINT '3'
GO

In this case, however, the print statement you want returned immediately is in the middle of a loop, so the print statements cannot be in their own batch. The only command I know of that will return in the middle of a batch is RAISERROR (...) WITH NOWAIT, which gbn has provided as an answer as I type this.

How to put an image next to each other

Check this out. Just use float and get rid of relative.

http://jsfiddle.net/JhpRk/

#icons{float:left;}

extracting days from a numpy.timedelta64 value

Suppose you have a timedelta series:

import pandas as pd
from datetime import datetime
z = pd.DataFrame({'a':[datetime.strptime('20150101', '%Y%m%d')],'b':[datetime.strptime('20140601', '%Y%m%d')]})

td_series = (z['a'] - z['b'])

One way to convert this timedelta column or series is to cast it to a Timedelta object (pandas 0.15.0+) and then extract the days from the object:

td_series.astype(pd.Timedelta).apply(lambda l: l.days)

Another way is to cast the series as a timedelta64 in days, and then cast it as an int:

td_series.astype('timedelta64[D]').astype(int)

Serializing PHP object to JSON

I spent some hours on the same problem. My object to convert contains many others whose definitions I'm not supposed to touch (API), so I've came up with a solution which could be slow I guess, but I'm using it for development purposes.

This one converts any object to array

function objToArr($o) {
$s = '<?php
class base {
    public static function __set_state($array) {
        return $array;
    }
}
function __autoload($class) {
    eval("class $class extends base {}");
}
$a = '.var_export($o,true).';
var_export($a);
';
$f = './tmp_'.uniqid().'.php';
file_put_contents($f,$s);
chmod($f,0755);
$r = eval('return '.shell_exec('php -f '.$f).';');
unlink($f);
return $r;
}

This converts any object to stdClass

class base {
    public static function __set_state($array) {
        return (object)$array;
    }
}
function objToStd($o) {
$s = '<?php
class base {
    public static function __set_state($array) {
        $o = new self;
        foreach($array as $k => $v) $o->$k = $v;
        return $o;
    }
}
function __autoload($class) {
    eval("class $class extends base {}");
}
$a = '.var_export($o,true).';
var_export($a);
';
$f = './tmp_'.uniqid().'.php';
file_put_contents($f,$s);
chmod($f,0755);
$r = eval('return '.shell_exec('php -f '.$f).';');
unlink($f);
return $r;
}

JSHint and jQuery: '$' is not defined

If you're using an IntelliJ editor such as WebStorm, PyCharm, RubyMine, or IntelliJ IDEA:

In the Environments section of File/Settings/JavaScript/Code Quality Tools/JSHint, click on the jQuery checkbox.

How to get GET (query string) variables in Express.js on Node.js?

You can use with express ^4.15.4:

var express = require('express'),
    router = express.Router();
router.get('/', function (req, res, next) {
    console.log(req.query);
});

Hope this helps.

enumerate() for dictionary in python

That sure must seem confusing. So this is what is going on. The first value of enumerate (in this case i) returns the next index value starting at 0 so 0, 1, 2, 3, ... It will always return these numbers regardless of what is in the dictionary. The second value of enumerate (in this case j) is returning the values in your dictionary/enumm (we call it a dictionary in Python). What you really want to do is what roadrunner66 responded with.

Get the client IP address using PHP

Here is a function to get the IP address using a filter for local and LAN IP addresses:

function get_IP_address()
{
    foreach (array('HTTP_CLIENT_IP',
                   'HTTP_X_FORWARDED_FOR',
                   'HTTP_X_FORWARDED',
                   'HTTP_X_CLUSTER_CLIENT_IP',
                   'HTTP_FORWARDED_FOR',
                   'HTTP_FORWARDED',
                   'REMOTE_ADDR') as $key){
        if (array_key_exists($key, $_SERVER) === true){
            foreach (explode(',', $_SERVER[$key]) as $IPaddress){
                $IPaddress = trim($IPaddress); // Just to be safe

                if (filter_var($IPaddress,
                               FILTER_VALIDATE_IP,
                               FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)
                    !== false) {

                    return $IPaddress;
                }
            }
        }
    }
}

Definition of int64_t

My 2 cents, from a current implementation Point of View and for SWIG users on k8 (x86_64) architecture.

Linux

First long long and long int are different types but sizeof(long long) == sizeof(long int) == sizeof(int64_t)

Gcc

First try to find where and how the compiler define int64_t and uint64_t

grepc -rn "typedef.*INT64_TYPE" /lib/gcc
/lib/gcc/x86_64-linux-gnu/9/include/stdint-gcc.h:43:typedef __INT64_TYPE__ int64_t;
/lib/gcc/x86_64-linux-gnu/9/include/stdint-gcc.h:55:typedef __UINT64_TYPE__ uint64_t;

So we need to find this compiler macro definition

gcc -dM -E -x c /dev/null | grep __INT64                 
#define __INT64_C(c) c ## L
#define __INT64_MAX__ 0x7fffffffffffffffL
#define __INT64_TYPE__ long int

gcc -dM -E -x c++ /dev/null | grep __INT64
#define __INT64_C(c) c ## L
#define __INT64_MAX__ 0x7fffffffffffffffL
#define __INT64_TYPE__ long int

Clang

clang -dM -E -x c++ /dev/null | grep INT64_TYPE
#define __INT64_TYPE__ long int
#define __UINT64_TYPE__ long unsigned int

Clang, GNU compilers:
-dM dumps a list of macros.
-E prints results to stdout instead of a file.
-x c and -x c++ select the programming language when using a file without a filename extension, such as /dev/null

Ref: https://web.archive.org/web/20190803041507/http://nadeausoftware.com/articles/2011/12/c_c_tip_how_list_compiler_predefined_macros

note: for swig user, on Linux x86_64 use -DSWIGWORDSIZE64

MacOS

On Catalina 10.15 IIRC

Clang

clang -dM -E -x c++ /dev/null | grep INT64_TYPE
#define __INT64_TYPE__ long long int
#define __UINT64_TYPE__ long long unsigned int

Clang:
-dM dumps a list of macros.
-E prints results to stdout instead of a file.
-x c and -x c++ select the programming language when using a file without a filename extension, such as /dev/null

Ref: https://web.archive.org/web/20190803041507/http://nadeausoftware.com/articles/2011/12/c_c_tip_how_list_compiler_predefined_macros

note: for swig user, on macOS x86_64 don't use -DSWIGWORDSIZE64

Visual Studio 2019

First sizeof(long int) == 4 and sizeof(long long) == 8

in stdint.h we have:

#if _VCRT_COMPILER_PREPROCESSOR

typedef signed char        int8_t;
typedef short              int16_t;
typedef int                int32_t;
typedef long long          int64_t;
typedef unsigned char      uint8_t;
typedef unsigned short     uint16_t;
typedef unsigned int       uint32_t;
typedef unsigned long long uint64_t;

note: for swig user, on windows x86_64 don't use -DSWIGWORDSIZE64

SWIG Stuff

First see https://github.com/swig/swig/blob/3a329566f8ae6210a610012ecd60f6455229fe77/Lib/stdint.i#L20-L24 so you can control the typedef using SWIGWORDSIZE64 but...

now the bad: SWIG Java and SWIG CSHARP do not take it into account

So you may want to use

#if defined(SWIGJAVA)
#if defined(SWIGWORDSIZE64)
%define PRIMITIVE_TYPEMAP(NEW_TYPE, TYPE)
%clear NEW_TYPE;
%clear NEW_TYPE *;
%clear NEW_TYPE &;
%clear const NEW_TYPE &;
%apply TYPE { NEW_TYPE };
%apply TYPE * { NEW_TYPE * };
%apply TYPE & { NEW_TYPE & };
%apply const TYPE & { const NEW_TYPE & };
%enddef // PRIMITIVE_TYPEMAP
PRIMITIVE_TYPEMAP(long int, long long);
PRIMITIVE_TYPEMAP(unsigned long int, long long);
#undef PRIMITIVE_TYPEMAP
#endif // defined(SWIGWORDSIZE64)
#endif // defined(SWIGJAVA)

and

#if defined(SWIGCSHARP)
#if defined(SWIGWORDSIZE64)
%define PRIMITIVE_TYPEMAP(NEW_TYPE, TYPE)
%clear NEW_TYPE;
%clear NEW_TYPE *;
%clear NEW_TYPE &;
%clear const NEW_TYPE &;
%apply TYPE { NEW_TYPE };
%apply TYPE * { NEW_TYPE * };
%apply TYPE & { NEW_TYPE & };
%apply const TYPE & { const NEW_TYPE & };
%enddef // PRIMITIVE_TYPEMAP
PRIMITIVE_TYPEMAP(long int, long long);
PRIMITIVE_TYPEMAP(unsigned long int, unsigned long long);
#undef PRIMITIVE_TYPEMAP
#endif // defined(SWIGWORDSIZE64)
#endif // defined(SWIGCSHARP)

So int64_t aka long int will be bind to Java/C# long on Linux...

Angular 5 - Copy to clipboard

Modified version of jockeisorby's answer that fixes the event handler not being properly removed.

copyToClipboard(item): void {
    let listener = (e: ClipboardEvent) => {
        e.clipboardData.setData('text/plain', (item));
        e.preventDefault();
    };

    document.addEventListener('copy', listener);
    document.execCommand('copy');
    document.removeEventListener('copy', listener);
}

Check whether specific radio button is checked

$("input[@name='<%=test2.ClientID%>']:checked");

use this and here ClientID fetch random id created by .net.

Connecting to SQL Server Express - What is my server name?

You should be able to see it in the Services panel. Look for a servicename like Sql Server (MSSQLSERVER). The name in the parentheses is your instance name.

Pretty-print an entire Pandas Series / DataFrame

After importing pandas, as an alternative to using the context manager, set such options for displaying entire dataframes:

pd.set_option('display.max_columns', None)  # or 1000
pd.set_option('display.max_rows', None)  # or 1000
pd.set_option('display.max_colwidth', -1)  # or 199

For full list of useful options, see:

pd.describe_option('display')

How can I get a user's media from Instagram without authenticating as a user?

Here is a php script that downloads the images and creates an html file with links on the images. Credit 350D for php version, this is just elaborated..I would suggest putting this is a cron job and firing however often you need. Verified working as of May 2019.

<?
$user = 'smena8m';
$igdata = file_get_contents('https://instagram.com/'.$user.'/');
preg_match('/_sharedData = ({.*);<\/script>/',$igdata,$matches);
$profile_data = json_decode($matches[1])->entry_data->ProfilePage[0]->graphql->user;
$html = '<div class="instagramBox" style="display:inline-grid;grid-template-columns:auto auto auto;">';
$i = 0;
$max = 9;
while($i<$max){
    $imglink = $profile_data->edge_owner_to_timeline_media->edges[$i]->node->shortcode;
    $img = $profile_data->edge_owner_to_timeline_media->edges[$i]->node->thumbnail_resources[0]->src;
    file_put_contents('ig'.$i.'.jpg',file_get_contents($img));
    $html .= '<a href="https://www.instagram.com/p/'.$imglink.'/" target="_blank"><img src="ig'.$i.'.jpg" /></a>';
    $i++;
}
$html .= '</div>';
$instagram = fopen('instagram.html','w');
fwrite($instagram,$html);
fclose($instagram);
?>

how to install multiple versions of IE on the same system?

I would use VMs. Create an XP (or whatever) VM using VMware Workstation or similar product, and snapshot it. That is your oldest version. Then perform the upgrades one at a time, and snapshot each time. Then you can switch to any snapshot you need later, or clone independent VMs based on all the snapshots so you can run them all at once. You probably want to test on different operating systems as well as different versions, so VMs generalize that solution as well rather than some one-off solution of hacking multiple IEs to coexist on a single instance of Windows.

How do I move a redis database from one server to another?

If you have the connectivity between servers it is better to set up replication (which is trivial, unlike with SQL) with the new instance as a slave node - then you can switch the new node to master with a single command and do the move with zero downtime.

How can I parse a JSON file with PHP?

When you decode a json string, you will get an object. not an array. So the best way to see the structure you are getting, is to make a var_dump of the decode. (this var_dump can help you understand the structure, mainly in complex cases).

<?php
     $json = file_get_contents('/home/michael/test.json');
     $json_a = json_decode($json);
     var_dump($json_a); // just to see the structure. It will help you for future cases
     echo "\n";
     foreach($json_a as $row){
         echo $row->status;
         echo "\n";
     }
?>

What is the difference between float and double?

  • A double is 64 and single precision (float) is 32 bits.
  • The double has a bigger mantissa (the integer bits of the real number).
  • Any inaccuracies will be smaller in the double.

How do I create and read a value from cookie?

An improved version of the readCookie:

function readCookie( name )
{
    var cookieParts = document.cookie.split( ';' )
    ,   i           = 0
    ,   part
    ,   part_data
    ,   value
    ;

    while( part = cookieParts[ i++ ] )
    {
        part_data = part.split( '=' );

        if ( part_data.shift().replace(/\s/, '' ) === name )
        {
            value = part_data.shift();
            break;
        }

    }
    return value;
}

This should break as soon as you have found your cookie value and return its value. In my opinion very elegant with the double split.

The replace on the if-condition is a white space trim, to make sure it matches correctly

Apply formula to the entire column

You can use Ctrl+Shift+Down+D to add the formula to every cell in the column as well.

Simply click/highlight the cell with the equation/formula you want to copy and then hold down Ctrl+Shift+Down+D and your formula will be added to each cell.

How do I check if an integer is even or odd?

I would build a table of the parities (0 if even 1 if odd) of the integers (so one could do a lookup :D), but gcc won't let me make arrays of such sizes:

typedef unsigned int uint;

char parity_uint [UINT_MAX];
char parity_sint_shifted [((uint) INT_MAX) + ((uint) abs (INT_MIN))];
char* parity_sint = parity_sint_shifted - INT_MIN;

void build_parity_tables () {
    char parity = 0;
    unsigned int ui;
    for (ui = 1; ui <= UINT_MAX; ++ui) {
        parity_uint [ui - 1] = parity;
        parity = !parity;
    }
    parity = 0;
    int si;
    for (si = 1; si <= INT_MAX; ++si) {
        parity_sint [si - 1] = parity;
        parity = !parity;
    }
    parity = 1;
    for (si = -1; si >= INT_MIN; --si) {
        parity_sint [si] = parity;
        parity = !parity;
    }
}

char uparity (unsigned int n) {
    if (n == 0) {
        return 0;
    }
    return parity_uint [n - 1];
}

char sparity (int n) {
    if (n == 0) {
        return 0;
    }
    if (n < 0) {
        ++n;
    }
    return parity_sint [n - 1];
}

So let's instead resort to the mathematical definition of even and odd instead.

An integer n is even if there exists an integer k such that n = 2k.

An integer n is odd if there exists an integer k such that n = 2k + 1.

Here's the code for it:

char even (int n) {
    int k;
    for (k = INT_MIN; k <= INT_MAX; ++k) {
        if (n == 2 * k) {
            return 1;
        }
    }
    return 0;
}

char odd (int n) {
    int k;
    for (k = INT_MIN; k <= INT_MAX; ++k) {
        if (n == 2 * k + 1) {
            return 1;
        }
    }
    return 0;
}

Let C-integers denote the possible values of int in a given C compilation. (Note that C-integers is a subset of the integers.)

Now one might worry that for a given n in C-integers that the corresponding integer k might not exist within C-integers. But with a little proof it is can be shown that for all integers n, |n| <= |2n| (*), where |n| is "n if n is positive and -n otherwise". In other words, for all n in integers at least one of the following holds (exactly either cases (1 and 2) or cases (3 and 4) in fact but I won't prove it here):

Case 1: n <= 2n.

Case 2: -n <= -2n.

Case 3: -n <= 2n.

Case 4: n <= -2n.

Now take 2k = n. (Such a k does exist if n is even, but I won't prove it here. If n is not even then the loop in even fails to return early anyway, so it doesn't matter.) But this implies k < n if n not 0 by (*) and the fact (again not proven here) that for all m, z in integers 2m = z implies z not equal to m given m is not 0. In the case n is 0, 2*0 = 0 so 0 is even we are done (if n = 0 then 0 is in C-integers because n is in C-integer in the function even, hence k = 0 is in C-integers). Thus such a k in C-integers exists for n in C-integers if n is even.

A similar argument shows that if n is odd, there exists a k in C-integers such that n = 2k + 1.

Hence the functions even and odd presented here will work properly for all C-integers.

Uncaught ReferenceError: function is not defined with onclick

Make sure you are using Javascript module or not?! if using js6 modules your html events attributes won't work. in that case you must bring your function from global scope to module scope. Just add this to your javascript file: window.functionName= functionName;

example:

<h1 onClick="functionName">some thing</h1>

GitHub: Permission denied (publickey). fatal: The remote end hung up unexpectedly

I faced a similar issue when running SSH or Git Clone in Windows. Following findings helps to solve my problem:

  • When you run “rhc setup” or other ssh methods to generate ssh key, it will create the private key file id_rsa in .ssh folder in your home folder, default is C:\User\UserID
  • Git for windows has its own .ssh folder in its installation directory. When you run git/ssh, it will look for private key file id_rsa in this folder
  • Solved the problem by copying id_rsa from the home folder .ssh folder to the .ssh folder in the git installation directory

Also, I think there a way to “tell” git to use the default .ssh folder in home folder but still need to figure out how.

while ($row = mysql_fetch_array($result)) - how many loops are being performed?

$query = "SELECT col1,col2,col3 FROM table WHERE id > 100"
$result = mysql_query($query);
if(mysql_num_rows($result)>0)
{
 while($row = mysql_fetch_array()) //here you can use many functions such as mysql_fetch_assoc() and other
 {
//It returns 1 row to your variable that becomes array and automatically go to the next result string
  Echo $row['col1']."|".Echo $row['col2']."|".Echo $row['col2'];
 }
}

How do I install TensorFlow's tensorboard?

If your Tensorflow install is located here:

/usr/local/lib/python2.7/dist-packages/tensorflow

then the python command to launch Tensorboard is:

$ python /usr/local/lib/python2.7/dist-packages/tensorflow/tensorboard/tensorboard.py --logdir=/home/user/Documents/.../logdir

The installation from pip allows you to use:

$ tensorboard --logdir=/home/user/Documents/.../logdir

jQuery get the location of an element relative to window

    function trbl(e, relative) {
            var r = $(e).get(0).getBoundingClientRect(); relative = $(relative);

            return {
                    t : r.top    + relative['scrollTop'] (),
                    r : r.right  + relative['scrollLeft'](),
                    b : r.bottom + relative['scrollTop'] (),
                    l : r.left   + relative['scrollLeft']() 

            }
    }

    // Example
    trbl(e, window);

How do I connect to an MDF database file?

For Visual Studio 2015 the connection string is:

"Data Source=(localdb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|Database1.mdf;Integrated Security=True"

Best C/C++ Network Library

Aggregated List of Libraries

Change Text Color of Selected Option in a Select Box

You could do it like this.

jsFiddle

JS

var select = document.getElementById('mySelect');
select.onchange = function () {
    select.className = this.options[this.selectedIndex].className;
}

CSS

.redText {
    background-color:#F00;
}
.greenText {
    background-color:#0F0;
}
.blueText {
    background-color:#00F;
}

You could use option { background-color: #FFF; } if you want the list to be white.

HTML

<select id="mySelect" class="greenText">
    <option class="greenText" value="apple" >Apple</option>
    <option class="redText"   value="banana" >Banana</option>
    <option class="blueText" value="grape" >Grape</option>
</select>

Since this is a select it doesn't really make sense to use .yellowText as none selected if that's what you were getting at as something must be selected.

Items in JSON object are out of order using "json.dumps"?

As others have mentioned the underlying dict is unordered. However there are OrderedDict objects in python. ( They're built in in recent pythons, or you can use this: http://code.activestate.com/recipes/576693/ ).

I believe that newer pythons json implementations correctly handle the built in OrderedDicts, but I'm not sure (and I don't have easy access to test).

Old pythons simplejson implementations dont handle the OrderedDict objects nicely .. and convert them to regular dicts before outputting them.. but you can overcome this by doing the following:

class OrderedJsonEncoder( simplejson.JSONEncoder ):
   def encode(self,o):
      if isinstance(o,OrderedDict.OrderedDict):
         return "{" + ",".join( [ self.encode(k)+":"+self.encode(v) for (k,v) in o.iteritems() ] ) + "}"
      else:
         return simplejson.JSONEncoder.encode(self, o)

now using this we get:

>>> import OrderedDict
>>> unordered={"id":123,"name":"a_name","timezone":"tz"}
>>> ordered = OrderedDict.OrderedDict( [("id",123), ("name","a_name"), ("timezone","tz")] )
>>> e = OrderedJsonEncoder()
>>> print e.encode( unordered )
{"timezone": "tz", "id": 123, "name": "a_name"}
>>> print e.encode( ordered )
{"id":123,"name":"a_name","timezone":"tz"}

Which is pretty much as desired.

Another alternative would be to specialise the encoder to directly use your row class, and then you'd not need any intermediate dict or UnorderedDict.

Redirect in Spring MVC

Also note that redirect: and forward: prefixes are handled by UrlBasedViewResolver, so you need to have at least one subclass of UrlBasedViewResolver among your view resolvers, such as InternalResourceViewResolver.

Converting float to char*

char array[10];
sprintf(array, "%f", 3.123);

sprintf: (from MSDN)

Collision resolution in Java HashMap

It isn't defined to do so. In order to achieve this functionality, you need to create a map that maps keys to lists of values:

Map<Foo, List<Bar>> myMap;

Or, you could use the Multimap from google collections / guava libraries

Check if my SSL Certificate is SHA1 or SHA2

I had to modify this slightly to be used on a Windows System. Here's the one-liner version for a windows box.

openssl.exe s_client -connect yoursitename.com:443 > CertInfo.txt && openssl x509 -text -in CertInfo.txt | find "Signature Algorithm" && del CertInfo.txt /F

Tested on Server 2012 R2 using http://iweb.dl.sourceforge.net/project/gnuwin32/openssl/0.9.8h-1/openssl-0.9.8h-1-bin.zip

CSV parsing in Java - working example..?

i had to use a csv parser about 5 years ago. seems there are at least two csv standards: http://en.wikipedia.org/wiki/Comma-separated_values and what microsoft does in excel.

i found this libaray which eats both: http://ostermiller.org/utils/CSV.html, but afaik, it has no way of inferring what data type the columns were.

Difference between float and decimal data type

declare @float as float(10)
declare @Decimal as decimal(10)
declare @Inetger as int

set @float =10.7
set @Decimal =10.7
set @Inetger=@Decimal

print @Inetger

in float when set value to integer print 10 but in decimal 11

cocoapods - 'pod install' takes forever

I ran into the same problem, and I solved it by running the following commands which is given here

pod repo remove master
pod setup
pod install

Get selected item value from Bootstrap DropDown with specific ID

$('#demolist li').on('click', function(){
    $('#datebox').val($(this).text());
});

http://jsfiddle.net/kcpma/18/

How to query DATETIME field using only date in Microsoft SQL Server?

I am using MySQL 5.6 and there is a DATE function to extract only the date part from date time. So the simple solution to the question is -

 select * from test where DATE(date) = '2014-03-19';

http://dev.mysql.com/doc/refman/5.6/en/date-and-time-functions.html

Edit seaborn legend

If legend_out is set to True then legend is available thought g._legend property and it is a part of a figure. Seaborn legend is standard matplotlib legend object. Therefore you may change legend texts like:

import seaborn as sns

tips = sns.load_dataset("tips")
g = sns.lmplot(x="total_bill", y="tip", hue="smoker",
 data=tips, markers=["o", "x"], legend_out = True)

# title
new_title = 'My title'
g._legend.set_title(new_title)
# replace labels
new_labels = ['label 1', 'label 2']
for t, l in zip(g._legend.texts, new_labels): t.set_text(l)

sns.plt.show()

enter image description here

Another situation if legend_out is set to False. You have to define which axes has a legend (in below example this is axis number 0):

import seaborn as sns

tips = sns.load_dataset("tips")
g = sns.lmplot(x="total_bill", y="tip", hue="smoker",
 data=tips, markers=["o", "x"], legend_out = False)

# check axes and find which is have legend
leg = g.axes.flat[0].get_legend()
new_title = 'My title'
leg.set_title(new_title)
new_labels = ['label 1', 'label 2']
for t, l in zip(leg.texts, new_labels): t.set_text(l)
sns.plt.show()

enter image description here

Moreover you may combine both situations and use this code:

import seaborn as sns

tips = sns.load_dataset("tips")
g = sns.lmplot(x="total_bill", y="tip", hue="smoker",
 data=tips, markers=["o", "x"], legend_out = True)

# check axes and find which is have legend
for ax in g.axes.flat:
    leg = g.axes.flat[0].get_legend()
    if not leg is None: break
# or legend may be on a figure
if leg is None: leg = g._legend

# change legend texts
new_title = 'My title'
leg.set_title(new_title)
new_labels = ['label 1', 'label 2']
for t, l in zip(leg.texts, new_labels): t.set_text(l)

sns.plt.show()

This code works for any seaborn plot which is based on Grid class.

How to make the checkbox unchecked by default always

This is browser specific behavior and is a way for making filling up forms more convenient to users (like reloading the page when an error has been encountered and not losing what they just typed). So there is no sure way to disable this across browsers short of setting the default values on page load using javascript.

Firefox though seems to disable this feature when you specify the header:

Cache-Control: no-store

See this question.

Ignore outliers in ggplot2 boxplot

Use geom_boxplot(outlier.shape = NA) to not display the outliers and scale_y_continuous(limits = c(lower, upper)) to change the axis limits.

An example.

n <- 1e4L
dfr <- data.frame(
  y = exp(rlnorm(n)),  #really right-skewed variable
  f = gl(2, n / 2)
)

p <- ggplot(dfr, aes(f, y)) + 
  geom_boxplot()
p   # big outlier causes quartiles to look too slim

p2 <- ggplot(dfr, aes(f, y)) + 
  geom_boxplot(outlier.shape = NA) +
  scale_y_continuous(limits = quantile(dfr$y, c(0.1, 0.9)))
p2  # no outliers plotted, range shifted

Actually, as Ramnath showed in his answer (and Andrie too in the comments), it makes more sense to crop the scales after you calculate the statistic, via coord_cartesian.

coord_cartesian(ylim = quantile(dfr$y, c(0.1, 0.9)))

(You'll probably still need to use scale_y_continuous to fix the axis breaks.)

How to create a simple http proxy in node.js?

Here's an implementation using node-http-proxy from nodejitsu.

var http = require('http');
var httpProxy = require('http-proxy');
var proxy = httpProxy.createProxyServer({});

http.createServer(function(req, res) {
    proxy.web(req, res, { target: 'http://www.google.com' });
}).listen(3000);

pdftk compression option

I didn't see a lot of reduction in file size using qpdf. The best way I found is after pdftk is done use ghostscript to convert pdf to postscript then back to pdf. In PHP you would use exec:

$ps = $save_path.'/psfile.ps';
exec('ps2ps2 ' . $pdf . ' ' . $ps);
unlink($pdf);
exec('ps2pdf ' .$ps . ' ' . $pdf);
unlink($ps);

I used this a few minutes ago to take pdftk output from 490k to 71k.

How do I POST XML data to a webservice with Postman?

Send XML requests with the raw data type, then set the Content-Type to text/xml.


  1. After creating a request, use the dropdown to change the request type to POST.

    Set request type to POST

  2. Open the Body tab and check the data type for raw.

    Setting data type to raw

  3. Open the Content-Type selection box that appears to the right and select either XML (application/xml) or XML (text/xml)

    Selecting content-type text/xml

  4. Enter your raw XML data into the input field below

    Example of XML request in Postman

  5. Click Send to submit your XML Request to the specified server.

    Clicking the Send button

How to get text from each cell of an HTML table?

Thanks for the earlier reply.

I figured out the solutions using selenium 2.0 classes.

import java.util.List;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.ie.InternetExplorerDriver;

public class WebTableExample 
{
    public static void main(String[] args) 
    {
        WebDriver driver = new InternetExplorerDriver();
        driver.get("http://localhost/test/test.html");      

        WebElement table_element = driver.findElement(By.id("testTable"));
        List<WebElement> tr_collection=table_element.findElements(By.xpath("id('testTable')/tbody/tr"));

        System.out.println("NUMBER OF ROWS IN THIS TABLE = "+tr_collection.size());
        int row_num,col_num;
        row_num=1;
        for(WebElement trElement : tr_collection)
        {
            List<WebElement> td_collection=trElement.findElements(By.xpath("td"));
            System.out.println("NUMBER OF COLUMNS="+td_collection.size());
            col_num=1;
            for(WebElement tdElement : td_collection)
            {
                System.out.println("row # "+row_num+", col # "+col_num+ "text="+tdElement.getText());
                col_num++;
            }
            row_num++;
        } 
    }
}

Parse Json string in C#

you can try with System.Web.Script.Serialization.JavaScriptSerializer:

var json = new JavaScriptSerializer();
var data = json.Deserialize<Dictionary<string, Dictionary<string, string>>[]>(jsonStr);

Converting newline formatting from Mac to Windows

In Xcode 9 in the left panel open/choose your file in project navigator. If file is not there, drug-and-drop it into the project navigator.

On right panel find Text Settings and change Line Endings to Windows (CRLF) .

XCode screendumpscreendump from XCode

Toggle display:none style with JavaScript

Give the UL an ID and use the getElementById function:

<html>
<body>
    <script>
    function toggledisplay(elementID)
    {
        (function(style) {
            style.display = style.display === 'none' ? '' : 'none';
        })(document.getElementById(elementID).style);
    }
    </script>

<a href="#" title="Show Tags" onClick="toggledisplay('changethis');">Show All Tags</a>
<ul class="subforums" id="changethis" style="overflow-x: visible; overflow-y: visible; ">
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
</ul>

</body>
</html>

How to remove MySQL completely with config and library files?

With the command:

sudo apt-get remove --purge mysql\*

you can delete anything related to packages named mysql. Those commands are only valid on debian / debian-based linux distributions (Ubuntu for example).

You can list all installed mysql packages with the command:

sudo dpkg -l | grep -i mysql

For more cleanup of the package cache, you can use the command:

sudo apt-get clean

Also, remember to use the command:

sudo updatedb

Otherwise the "locate" command will display old data.

To install mysql again, use the following command:

sudo apt-get install libmysqlclient-dev mysql-client

This will install the mysql client, libmysql and its headers files.

To install the mysql server, use the command:

sudo apt-get install mysql-server

Tools to search for strings inside files without indexing

There is also a Windows built-in program called findstr.exe with which you can search within files.

>findstr /s "provider=sqloledb" *.cs

Meaning of *& and **& in C++

First is a reference to a pointer, second is a reference to a pointer to a pointer. See also FAQ on how pointers and references differ.

void foo(int*& x, int**& y) {
    // modifying x or y here will modify a or b in main
}

int main() {
    int val = 42;
    int *a  = &val;
    int **b = &a;

    foo(a, b);
    return 0;
}

Why is the gets function so dangerous that it should not be used?

gets() is dangerous because it is possible for the user to crash the program by typing too much into the prompt. It can't detect the end of available memory, so if you allocate an amount of memory too small for the purpose, it can cause a seg fault and crash. Sometimes it seems very unlikely that a user will type 1000 letters into a prompt meant for a person's name, but as programmers, we need to make our programs bulletproof. (it may also be a security risk if a user can crash a system program by sending too much data).

fgets() allows you to specify how many characters are taken out of the standard input buffer, so they don't overrun the variable.

Pandas join issue: columns overlap but no suffix specified

The error indicates that the two tables have the 1 or more column names that have the same column name.

Anyone with the same error who doesn't want to provide a suffix can rename the columns instead. Also make sure the index of both DataFrames match in type and value if you don't want to provide the on='mukey' setting.

# rename example
df_a = df_a.rename(columns={'a_old': 'a_new', 'a2_old': 'a2_new'})
# set the index
df_a = df_a.set_index(['mukus'])
df_b = df_b.set_index(['mukus'])

df_a.join(df_b)

What is the best way to delete a component with CLI

destroy or something similar may come to the CLI, but it is not a primary focus at this time. So you will need to do this manually.

Delete the component directory (assuming you didn't use --flat) and then remove it from the NgModule in which it is declared.

If you are unsure of what to do, I suggest you have a "clean" app meaning no current git changes. Then generate a component and see what is changed in the repo so you can backtrack from there what you will need to do to delete a component.

Update

If you're just experimenting about what you want to generate, you can use the --dry-run flag to not produce any files on disk, just see the updated file list.

Display Images Inline via CSS

You have a line break <br> in-between the second and third images in your markup. Get rid of that, and it'll show inline.

Internal Error 500 Apache, but nothing in the logs?

Check that the version of php you're running matches your codebase. For example, your local environment may be running php 5.4 (and things run fine) and maybe you're testing your code on a new machine that has php 5.3 installed. If you are using 5.4 syntax such as [] for array() then you'll get the situation you described above.

How do I close an Android alertdialog

Use Dialog instead of AlertDialog

AlertDialog doesn't have dismiss() but AlertDialog has some methods for button like setPositiveButton().

I recommend to use Dialog if you want customized dialog.

What is the benefit of using "SET XACT_ABORT ON" in a stored procedure?

Regarding client timeouts and the use of XACT_ABORT to handle them, in my opinion there is at least one very good reason to have timeouts in client APIs like SqlClient, and that is to guard the client application code from deadlocks occurring in SQL server code. In this case the client code has no fault, but has to protect it self from blocking forever waiting for the command to complete on the server. So conversely, if client timeouts have to exist to protect client code, so does XACT_ABORT ON has to protect server code from client aborts, in case the server code takes longer to execute than the client is willing to wait for.

Creating a new directory in C

I want to write a program that (...) creates the directory and a (...) file inside of it

because this is a very common question, here is the code to create multiple levels of directories and than call fopen. I'm using a gnu extension to print the error message with printf.

void rek_mkdir(char *path) {
    char *sep = strrchr(path, '/');
    if(sep != NULL) {
        *sep = 0;
        rek_mkdir(path);
        *sep = '/';
    }
    if(mkdir(path, 0777) && errno != EEXIST)
        printf("error while trying to create '%s'\n%m\n", path); 
}

FILE *fopen_mkdir(char *path, char *mode) {
    char *sep = strrchr(path, '/');
    if(sep) { 
        char *path0 = strdup(path);
        path0[ sep - path ] = 0;
        rek_mkdir(path0);
        free(path0);
    }
    return fopen(path,mode);
}

Using the AND and NOT Operator in Python

It's called and and or in Python.

Basic authentication for REST API using spring restTemplate

As of Spring 5.1 you can use HttpHeaders.setBasicAuth

Create Basic Authorization header:

String username = "willie";
String password = ":p@ssword";
HttpHeaders headers = new HttpHeaders();
headers.setBasicAuth(username, password);
...other headers goes here...

Pass the headers to the RestTemplate:

HttpEntity<String> request = new HttpEntity<String>(headers);
ResponseEntity<Account> response = restTemplate.exchange(url, HttpMethod.GET, request, Account.class);
Account account = response.getBody();

Documentation: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/http/HttpHeaders.html#setBasicAuth-java.lang.String-java.lang.String-

How to use System.Net.HttpClient to post a complex type?

In case someone like me didn't really understand what all above are talking about, I give an easy example which is working for me. If you have a web api which url is "http://somesite.com/verifyAddress", it is a post method and it need you to pass it an address object. You want to call this api in your code. Here what you can do.

    public Address verifyAddress(Address address)
    {
        this.client = new HttpClient();
        client.BaseAddress = new Uri("http://somesite.com/");
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        var urlParm = URL + "verifyAddress";
        response = client.PostAsJsonAsync(urlParm,address).Result;
        var dataObjects = response.IsSuccessStatusCode ? response.Content.ReadAsAsync<Address>().Result : null;
        return dataObjects;
    }

How can I add a string to the end of each line in Vim?

...and to prepend (add the beginning of) each line with *,

%s/^/*/g

Refreshing page on click of a button

I'd suggest <a href='page1.jsp'>Refresh</a>.

Python list iterator behavior and next(iterator)

What is happening is that next(a) returns the next value of a, which is printed to the console because it is not affected.

What you can do is affect a variable with this value:

>>> a = iter(list(range(10)))
>>> for i in a:
...    print(i)
...    b=next(a)
...
0
2
4
6
8

How to instantiate, initialize and populate an array in TypeScript?

There isn't a field initialization syntax like that for objects in JavaScript or TypeScript.

Option 1:

class bar {
    // Makes a public field called 'length'
    constructor(public length: number) { }
}

bars = [ new bar(1) ];

Option 2:

interface bar {
    length: number;
}

bars = [ {length: 1} ];

Static Initialization Blocks

I would say static block is just syntactic sugar. There is nothing you could do with static block and not with anything else.

To re-use some examples posted here.

This piece of code could be re-written without using static initialiser.

Method #1: With static

private static final HashMap<String, String> MAP;
static {
    MAP.put("banana", "honey");
    MAP.put("peanut butter", "jelly");
    MAP.put("rice", "beans");
  }

Method #2: Without static

private static final HashMap<String, String> MAP = getMap();
private static HashMap<String, String> getMap()
{
    HashMap<String, String> ret = new HashMap<>();
    ret.put("banana", "honey");
    ret.put("peanut butter", "jelly");
    ret.put("rice", "beans");
    return ret;
}

How to get JavaScript caller function line number? How to get JavaScript caller source URL?

This works for me in chrome/QtWebView

function getErrorObject(){
    try { throw Error('') } catch(err) { return err; }
}

var err = getErrorObject();
var caller_line = err.stack.split("\n")[4];
var index = caller_line.indexOf("at ");
var clean = caller_line.slice(index+2, caller_line.length);

How to split string using delimiter char using T-SQL?

For your specific data, you can use

Select col1, col2, LTRIM(RTRIM(SUBSTRING(
    STUFF(col3, CHARINDEX('|', col3,
    PATINDEX('%|Client Name =%', col3) + 14), 1000, ''),
    PATINDEX('%|Client Name =%', col3) + 14, 1000))) col3
from Table01

EDIT - charindex vs patindex

Test

select col3='Clent ID = 4356hy|Client Name = B B BOB|Client Phone = 667-444-2626|Client Fax = 666-666-0151|Info = INF8888877 -MAC333330554/444400800'
into t1m
from master..spt_values a
cross join master..spt_values b
where a.number < 100
-- (711704 row(s) affected)

set statistics time on

dbcc dropcleanbuffers
dbcc freeproccache
select a=CHARINDEX('|Client Name =', col3) into #tmp1 from t1m
drop table #tmp1

dbcc dropcleanbuffers
dbcc freeproccache
select a=PATINDEX('%|Client Name =%', col3) into #tmp2 from t1m
drop table #tmp2

set statistics time off

Timings

CHARINDEX:

 SQL Server Execution Times (1):
   CPU time = 5656 ms,  elapsed time = 6418 ms.
 SQL Server Execution Times (2):
   CPU time = 5813 ms,  elapsed time = 6114 ms.
 SQL Server Execution Times (3):
   CPU time = 5672 ms,  elapsed time = 6108 ms.

PATINDEX:

 SQL Server Execution Times (1):
   CPU time = 5906 ms,  elapsed time = 6296 ms.
 SQL Server Execution Times (2):
   CPU time = 5860 ms,  elapsed time = 6404 ms.
 SQL Server Execution Times (3):
   CPU time = 6109 ms,  elapsed time = 6301 ms.

Conclusion

The timings for CharIndex and PatIndex for 700k calls are within 3.5% of each other, so I don't think it would matter whichever is used. I use them interchangeably when both can work.

How can I read and manipulate CSV file data in C++?

I found this interesting approach:

CSV to C structure utility

Quote: CSVtoC is a program that takes a CSV or comma-separated values file as input and dumps it as a C structure.

Naturally, you can't make changes to the CSV file, but if you just need in-memory read-only access to the data, it could work.

How to use unicode characters in Windows command line?

A quick decision for .bat files if you computer displays your path/file name correct when you typing it in DOS-window:

  1. copy con temp.txt [press Enter]
  2. Type the path/file name [press Enter]
  3. Press Ctrl-Z [press Enter]

This way you create a .txt file - temp.txt. Open it in Notepad, copy the text (don't worry it will look unreadable) and paste it in your .bat file. Executing the .bat created this way in DOS-window worked for m? (Cyrillic, Bulgarian).

What are some resources for getting started in operating system development?

I found Robert Love's Linux Kernel Development quite interesting. It tells you about how the different subsystems in the Linux kernel works in a very down-to-earth way. Since the source is available Linux is a prime candidate for something to hack on.

How to set session timeout dynamically in Java web applications?

Instead of using a ServletContextListener, use a HttpSessionListener.

In the sessionCreated() method, you can set the session timeout programmatically:

public class MyHttpSessionListener implements HttpSessionListener {

  public void sessionCreated(HttpSessionEvent event){
      event.getSession().setMaxInactiveInterval(15 * 60); // in seconds
  }

  public void sessionDestroyed(HttpSessionEvent event) {}

}

And don't forget to define the listener in the deployment descriptor:

<webapp>
...      
  <listener>                                  
    <listener-class>com.example.MyHttpSessionListener</listener-class>
  </listener>
</webapp>

(or since Servlet version 3.0 you can use @WebListener annotation instead).


Still, I would recommend creating different web.xml files for each application and defining the session timeout there:

<webapp>
...
  <session-config>
    <session-timeout>15</session-timeout> <!-- in minutes -->
  </session-config>
</webapp>

vim line numbers - how to have them on by default?

To change the default setting to display line numbers in vi/vim:

vi ~/.vimrc

then add the following line to the file:

set number

Either we can source ~/.vimrc or save and quit by :wq, now future vi/vim sessions will have numbering :)

What are .tpl files? PHP, web design

The files are using some sort of template engine in which curly braces indicate variables being generated by that templating engine, the files creating such variables must be present elsewhere with the more or less same name as the tpl file name. Here are some of templates engine mostly used.

Smarty

Savant

Tinybutstrong

etc

With smarty being widely used.

Best timestamp format for CSV/Excel?

For second accuracy, yyyy-MM-dd HH:mm:ss should do the trick.

I believe Excel is not very good with fractions of a second (loses them when interacting with COM object IIRC).

JavaScript: get code to run every minute

You could use setInterval for this.

<script type="text/javascript">
function myFunction () {
    console.log('Executed!');
}

var interval = setInterval(function () { myFunction(); }, 60000);
</script>

Disable the timer by setting clearInterval(interval).

See this Fiddle: http://jsfiddle.net/p6NJt/2/

How to find all links / pages on a website

Another alternative might be

Array.from(document.querySelectorAll("a")).map(x => x.href)

With your $$( its even shorter

Array.from($$("a")).map(x => x.href)

Python dict how to create key or append an element to key?

Use dict.setdefault():

dic.setdefault(key,[]).append(value)

help(dict.setdefault):

    setdefault(...)
        D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D

LINQ query to return a Dictionary<string, string>

Look at the ToLookup and/or ToDictionary extension methods.

Get gateway ip address in android

DNS server is obtained via

getprop net.dns1 

UPDATE: as of Android Nougat 7.x, ifconfig is present, and netcfg is gone. So ifconfig can be used to find the IP and netmask.

paint() and repaint() in Java

The paint() method supports painting via a Graphics object.

The repaint() method is used to cause paint() to be invoked by the AWT painting thread.

Returning a C string from a function

A char is only a single one-byte character. It can't store the string of characters, nor is it a pointer (which you apparently cannot have). Therefore you cannot solve your problem without using pointers (which char[] is syntactic sugar for).

DB2 Timestamp select statement

You might want to use TRUNC function on your column when comparing with string format, so it compares only till seconds, not milliseconds.

SELECT * FROM <table_name> WHERE id = 1 
AND TRUNC(usagetime, 'SS') = '2012-09-03 08:03:06';

If you wanted to truncate upto minutes, hours, etc. that is also possible, just use appropriate notation instead of 'SS':

hour ('HH'), minute('MI'), year('YEAR' or 'YYYY'), month('MONTH' or 'MM'), Day ('DD')

How to SUM two fields within an SQL query

The sum function only gets the total of a column. In order to sum two values from different columns, convert the values to int and add them up using the +-Operator

Select (convert(int, col1)+convert(int, col2)) as summed from tbl1

Hope that helps.

@Nullable annotation usage

It makes it clear that the method accepts null values, and that if you override the method, you should also accept null values.

It also serves as a hint for code analyzers like FindBugs. For example, if such a method dereferences its argument without checking for null first, FindBugs will emit a warning.

How to reduce a huge excel file

I have worked extensively in Excel and have found the following 3 points very useful

Find if there are cells which apparently do not hold any data but Excel considers them to have data

You can find this by using the following property on a sheet

ActiveSheet.UsedRange.Rows.Count
ActiveSheet.UsedRange.Columns.Count

If this range is more than the cells on which you have data, delete the rest of the rows/columns

You will be surprised to see the amount of space it can free

Convert files to .xlsb format

XLSM format is to make Excel compliant with Open XML, but there are very few instances when we actually use the XML format of Excel. This reduces size by almost 50% if not more

Optimum way of storing information

For example if you have to save the stock price for around 10 years, and you need to save Open, High, Low, Close for a stock, this would result in (252*10) * (4) cells being used

Instead, of using separate columns for Open,High,Low,Close save them in a single column with a field separator Open:High:Low:Close

You can easily write a function to extract info from the single column whenever you want to, but it will free up almost 2/3rd space that you are currently taking up

Shell Scripting: Using a variable to define a path

To add to the above correct answer :- For my case in shell, this code worked (working on sqoop)

ROOT_PATH="path/to/the/folder"
--options-file  $ROOT_PATH/query.txt

How can I prevent a window from being resized with tkinter?

This code makes a window with the conditions that the user cannot change the dimensions of the Tk() window, and also disables the maximise button.

import tkinter as tk

root = tk.Tk()
root.resizable(width=False, height=False)
root.mainloop()

Within the program you can change the window dimensions with @Carpetsmoker's answer, or by doing this:

root.geometry('{}x{}'.format(<widthpixels>, <heightpixels>))

It should be fairly easy for you to implement that into your code. :)

Set padding for UITextField with UITextBorderStyleNone

Another consideration is that, if you have more than one UITextField where you are adding padding, is to create a separate UIView for each textfield - because they cannot be shared.

Error: Cannot find module 'gulp-sass'

I had the same problem, and I resolve doing this npm update. But I receive the message about permission, so I run:

sudo chwon -R myuser /home/myUserFolder/.config

This set permissions for my user run npm comands like administrator. Then I run this again:

npm update 

and this:

npm install gulp-sass

Then my problem with this was solved.

Can't get value of input type="file"?

don't give this in file input value="123".

  $(document).ready(function(){  

      var img = $('#uploadPicture').val();

  });

How do I find files that do not contain a given string pattern?

another alternative when grep doesn't have the -L option (IBM AIX for example), with nothing but grep and the shell :

for file in * ; do grep -q 'my_pattern' $file || echo $file ; done

How to return a PNG image from Jersey REST service method to the browser

I'm not convinced its a good idea to return image data in a REST service. It ties up your application server's memory and IO bandwidth. Much better to delegate that task to a proper web server that is optimized for this kind of transfer. You can accomplish this by sending a redirect to the image resource (as a HTTP 302 response with the URI of the image). This assumes of course that your images are arranged as web content.

Having said that, if you decide you really need to transfer image data from a web service you can do so with the following (pseudo) code:

@Path("/whatever")
@Produces("image/png")
public Response getFullImage(...) {

    BufferedImage image = ...;

    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    ImageIO.write(image, "png", baos);
    byte[] imageData = baos.toByteArray();

    // uncomment line below to send non-streamed
    // return Response.ok(imageData).build();

    // uncomment line below to send streamed
    // return Response.ok(new ByteArrayInputStream(imageData)).build();
}

Add in exception handling, etc etc.

How to write dynamic variable in Ansible playbook

I am sure there is a smarter way for doing what you want but this should work:

- name         : Test var
  hosts        : all
  gather_facts : no
  vars:
    myvariable : false
  tasks:
    - name: param1
      set_fact:
        myvariable: "{{param1}}"
      when: param1 is defined

    - name: param2
      set_fact:
        myvariable: "{{ param2 if not myvariable else myvariable + ',' + param2 }}"
      when: param2 is defined

    - name: param3
      set_fact:
        myvariable: "{{ param3 if not myvariable else myvariable + ',' + param3 }}"
      when: param3 is defined

    - name: default
      set_fact:
        myvariable: "default"
      when: not myvariable

    - debug:
       var=myvariable

Hope that helps. I am not sure if you can construct variables dynamically and do this in an iterator. But you could also write a small python code or any other language and plug it into ansible

Convert MySql DateTime stamp into JavaScript's Date format

Some of the answers given here are either overcomplicated or just will not work (at least, not in all browsers). If you take a step back, you can see that the MySQL timestamp has each component of time in the same order as the arguments required by the Date() constructor.

All that's needed is a very simple split on the string:

// Split timestamp into [ Y, M, D, h, m, s ]
var t = "2010-06-09 13:12:01".split(/[- :]/);

// Apply each element to the Date function
var d = new Date(Date.UTC(t[0], t[1]-1, t[2], t[3], t[4], t[5]));

console.log(d);
// -> Wed Jun 09 2010 14:12:01 GMT+0100 (BST)

Fair warning: this assumes that your MySQL server is outputting UTC dates (which is the default, and recommended if there is no timezone component of the string).

How to enable file sharing for my app?

New XCode 7 will only require 'UIFileSharingEnabled' key in Info.plist. 'CFBundleDisplayName' is not required any more.

One more hint: do not only modify the Info.plist of the 'tests' target. The main app and the 'tests' have different Info.plist.

How can I stop python.exe from closing immediately after I get an output?

You can't - globally, i.e. for every python program. And this is a good thing - Python is great for scripting (automating stuff), and scripts should be able to run without any user interaction at all.

However, you can always ask for input at the end of your program, effectively keeping the program alive until you press return. Use input("prompt: ") in Python 3 (or raw_input("promt: ") in Python 2). Or get used to running your programs from the command line (i.e. python mine.py), the program will exit but its output remains visible.

How to stop console from closing on exit?

You could open a command prompt, CD to the Debug or Release folder, and type the name of your exe. When I suggest this to people they think it is a lot of work, but here are the bare minimum clicks and keystrokes for this:

  • in Visual Studio, right click your project in Solution Explorer or the tab with the file name if you have a file in the solution open, and choose Open Containing Folder or Open in Windows Explorer
  • in the resulting Windows Explorer window, double-click your way to the folder with the exe
  • Shift-right-click in the background of the explorer window and choose Open Commmand Window here
  • type the first letter of your executable and press tab until the full name appears
  • press enter

I think that's 14 keystrokes and clicks (counting shift-right-click as two for example) which really isn't much. Once you have the command prompt, of course, running it again is just up-arrow, enter.

What are the different types of keys in RDBMS?

Partial Key:

It is a set of attributes that can uniquely identify weak entities and that are related to same owner entity. It is sometime called as Discriminator.

Alternate Key:

All Candidate Keys excluding the Primary Key are known as Alternate Keys.

Artificial Key:

If no obvious key, either stand alone or compound is available, then the last resort is to simply create a key, by assigning a unique number to each record or occurrence. Then this is known as developing an artificial key.

Compound Key:

If no single data element uniquely identifies occurrences within a construct, then combining multiple elements to create a unique identifier for the construct is known as creating a compound key.

Natural Key:

When one of the data elements stored within a construct is utilized as the primary key, then it is called the natural key.

Iterating through map in template

As Herman pointed out, you can get the index and element from each iteration.

{{range $index, $element := .}}{{$index}}
{{range $element}}{{.Value}}
{{end}}
{{end}}

Working example:

package main

import (
    "html/template"
    "os"
)

type EntetiesClass struct {
    Name string
    Value int32
}

// In the template, we use rangeStruct to turn our struct values
// into a slice we can iterate over
var htmlTemplate = `{{range $index, $element := .}}{{$index}}
{{range $element}}{{.Value}}
{{end}}
{{end}}`

func main() {
    data := map[string][]EntetiesClass{
        "Yoga": {{"Yoga", 15}, {"Yoga", 51}},
        "Pilates": {{"Pilates", 3}, {"Pilates", 6}, {"Pilates", 9}},
    }

    t := template.New("t")
    t, err := t.Parse(htmlTemplate)
    if err != nil {
        panic(err)
    }

    err = t.Execute(os.Stdout, data)
    if err != nil {
        panic(err)
    }

}

Output:

Pilates
3
6
9

Yoga
15
51

Playground: http://play.golang.org/p/4ISxcFKG7v

Python error: AttributeError: 'module' object has no attribute

More accurately, your mod1 and lib directories are not modules, they are packages. The file mod11.py is a module.

Python does not automatically import subpackages or modules. You have to explicitly do it, or "cheat" by adding import statements in the initializers.

>>> import lib
>>> dir(lib)
['__builtins__', '__doc__', '__file__', '__name__', '__package__', '__path__']
>>> import lib.pkg1
>>> import lib.pkg1.mod11
>>> lib.pkg1.mod11.mod12()
mod12

An alternative is to use the from syntax to "pull" a module from a package into you scripts namespace.

>>> from lib.pkg1 import mod11

Then reference the function as simply mod11.mod12().

What possibilities can cause "Service Unavailable 503" error?

Primarily what that means is that there are too many concurrent requests and further that they exceed the default 1000 queued requests. That is there are 1000 or more queued requests to your website.

This could happen (assuming there are no faults in your app) if there are long running tasks and as a result the Request queue is backed up.

Depending on how the application pool has been set up you may see this kind of thing. Typically, the app pool's Process Model has an item called Maximum Worker Processes. By default this is 1. If you set it to more than 1 (typically up to a max of the number of cores on the hardware) you may not see this happen.

Just to note that unless the site is extremely busy you should not see this. If you do, it's really pointing to long running tasks

How to convert hex to ASCII characters in the Linux shell?

As per @Randal comment, you can use perl, e.g.

$ printf 5a5a5a5a | perl -lne 'print pack "H*", $_'
ZZZZ

and other way round:

$ printf ZZZZ | perl -lne 'print unpack "H*", $_'
5a5a5a5a

Another example with file:

$ printf 5a5a5a5a | perl -lne 'print pack "H*", $_' > file.bin
$ perl -lne 'print unpack "H*", $_' < file.bin
5a5a5a5a

What is the difference between venv, pyvenv, pyenv, virtualenv, virtualenvwrapper, pipenv, etc?

UPDATE 20200825:

Added below "Conclusion" paragraph

I've went down the pipenv rabbit hole (it's a deep and dark hole indeed...) and since the last answer is over 2 years ago, felt it was useful to update the discussion with the latest developments on the Python virtual envelopes topic I've found.

DISCLAIMER:

This answer is NOT about continuing the raging debate about the merits of pipenv versus venv as envelope solutions- I make no endorsement of either. It's about PyPA endorsing conflicting standards and how future development of virtualenv promises to negate making an either/or choice between them at all. I focused on these two tools precisely because they are the anointed ones by PyPA.

venv

As the OP notes, venv is a tool for virtualizing environments. NOT a third party solution, but native tool. PyPA endorses venv for creating VIRTUAL ENVELOPES: "Changed in version 3.5: The use of venv is now recommended for creating virtual environments".

pipenv

pipenv- like venv - can be used to create virtual envelopes but additionally rolls-in package management and vulnerability checking functionality. Instead of using requirements.txt, pipenv delivers package management via Pipfile. As PyPA endorses pipenv for PACKAGE MANAGEMENT, that would seem to imply pipfile is to supplant requirements.txt.

HOWEVER: pipenv uses virtualenv as its tool for creating virtual envelopes, NOT venv which is endorsed by PyPA as the go-to tool for creating virtual envelopes.

Conflicting Standards:

So if settling on a virtual envelope solution wasn't difficult enough, we now have PyPA endorsing two different tools which use different virtual envelope solutions. The raging Github debate on venv vs virtualenv which highlights this conflict can be found here.

Conflict Resolution:

The Github debate referenced in above link has steered virtualenv development in the direction of accommodating venv in future releases:

prefer built-in venv: if the target python has venv we'll create the environment using that (and then perform subsequent operations on that to facilitate other guarantees we offer)

Conclusion:

So it looks like there will be some future convergence between the two rival virtual envelope solutions, but as of now pipenv- which uses virtualenv - varies materially from venv.

Given the problems pipenv solves and the fact that PyPA has given its blessing, it appears to have a bright future. And if virtualenv delivers on its proposed development objectives, choosing a virtual envelope solution should no longer be a case of either pipenv OR venv.

Update 20200825:

An oft repeated criticism of Pipenv I saw when producing this analysis was that it was not actively maintained. Indeed, what's the point of using a solution whose future could be seen questionable due to lack of continuous development? After a dry spell of about 18 months, Pipenv is once again being actively developed. Indeed, large and material updates have since been released.

Python: split a list based on a condition?

I think a generalization of splitting a an iterable based on N conditions is handy

from collections import OrderedDict
def partition(iterable,*conditions):
    '''Returns a list with the elements that satisfy each of condition.
       Conditions are assumed to be exclusive'''
    d= OrderedDict((i,list())for i in range(len(conditions)))        
    for e in iterable:
        for i,condition in enumerate(conditions):
            if condition(e):
                d[i].append(e)
                break                    
    return d.values()

For instance:

ints,floats,other = partition([2, 3.14, 1, 1.69, [], None],
                              lambda x: isinstance(x, int), 
                              lambda x: isinstance(x, float),
                              lambda x: True)

print " ints: {}\n floats:{}\n other:{}".format(ints,floats,other)

 ints: [2, 1]
 floats:[3.14, 1.69]
 other:[[], None]

If the element may satisfy multiple conditions, remove the break.

How can I pass a reference to a function, with parameters?

The following is equivalent to your second code block:

var f = function () {
        //Some logic here...
    };

var fr = f;

fr(pars);

If you want to actually pass a reference to a function to some other function, you can do something like this:

function fiz(x, y, z) {
    return x + y + z;
}

// elsewhere...

function foo(fn, p, q, r) {
    return function () {
        return fn(p, q, r);
    }
}

// finally...

f = foo(fiz, 1, 2, 3);
f(); // returns 6

You're almost certainly better off using a framework for this sort of thing, though.

How to convert LINQ query result to List?

You need to use the select new LINQ keyword to explicitly convert your tbcourseentity into the custom type course. Example of select new:

var q = from o in db.Orders
        where o.Products.ProductName.StartsWith("Asset") && 
              o.PaymentApproved == true
        select new { name   = o.Contacts.FirstName + " " +
                              o.Contacts.LastName, 
                     product = o.Products.ProductName, 
                     version = o.Products.Version + 
                              (o.Products.SubVersion * 0.1)
                   };

http://www.hookedonlinq.com/LINQtoSQL5MinuteOverview.ashx

How to add an element to Array and shift indexes?

Here is a quasi-oneliner that does it:

String[] prependedArray = new ArrayList<String>() {
  {
    add("newElement");
    addAll(Arrays.asList(originalArray));
  }
}.toArray(new String[0]);

Java Comparator class to sort arrays

[...] How should Java Comparator class be declared to sort the arrays by their first elements in decreasing order [...]

Here's a complete example using Java 8:

import java.util.*;

public class Test {

    public static void main(String args[]) {

        int[][] twoDim = { {1, 2}, {3, 7}, {8, 9}, {4, 2}, {5, 3} };

        Arrays.sort(twoDim, Comparator.comparingInt(a -> a[0])
                                      .reversed());

        System.out.println(Arrays.deepToString(twoDim));
    }
}

Output:

[[8, 9], [5, 3], [4, 2], [3, 7], [1, 2]]

For Java 7 you can do:

Arrays.sort(twoDim, new Comparator<int[]>() {
    @Override
    public int compare(int[] o1, int[] o2) {
        return Integer.compare(o2[0], o1[0]);
    }
});

If you unfortunate enough to work on Java 6 or older, you'd do:

Arrays.sort(twoDim, new Comparator<int[]>() {
    @Override
    public int compare(int[] o1, int[] o2) {
        return ((Integer) o2[0]).compareTo(o1[0]);
    }
});

Git checkout - switching back to HEAD

You can stash (save the changes in temporary box) then, back to master branch HEAD.

$ git add .
$ git stash
$ git checkout master

Jump Over Commits Back and Forth:

  • Go to a specific commit-sha.

      $ git checkout <commit-sha>
    
  • If you have uncommitted changes here then, you can checkout to a new branch | Add | Commit | Push the current branch to the remote.

      # checkout a new branch, add, commit, push
      $ git checkout -b <branch-name>
      $ git add .
      $ git commit -m 'Commit message'
      $ git push origin HEAD          # push the current branch to remote 
    
      $ git checkout master           # back to master branch now
    
  • If you have changes in the specific commit and don't want to keep the changes, you can do stash or reset then checkout to master (or, any other branch).

      # stash
      $ git add -A
      $ git stash
      $ git checkout master
    
      # reset
      $ git reset --hard HEAD
      $ git checkout master
    
  • After checking out a specific commit if you have no uncommitted change(s) then, just back to master or other branch.

      $ git status          # see the changes
      $ git checkout master
    
      # or, shortcut
      $ git checkout -      # back to the previous state
    

For each row in an R dataframe

I think the best way to do this with basic R is:

for( i in rownames(df) )
   print(df[i, "column1"])

The advantage over the for( i in 1:nrow(df))-approach is that you do not get into trouble if df is empty and nrow(df)=0.

How to extract the decision rules from scikit-learn decision-tree?

Now you can use export_text.

from sklearn.tree import export_text

r = export_text(loan_tree, feature_names=(list(X_train.columns)))
print(r)

A complete example from [sklearn][1]

from sklearn.datasets import load_iris
from sklearn.tree import DecisionTreeClassifier
from sklearn.tree import export_text
iris = load_iris()
X = iris['data']
y = iris['target']
decision_tree = DecisionTreeClassifier(random_state=0, max_depth=2)
decision_tree = decision_tree.fit(X, y)
r = export_text(decision_tree, feature_names=iris['feature_names'])
print(r)

How to create a Rectangle object in Java using g.fillRect method

You may try like this:

import java.applet.Applet;
import java.awt.*;

public class Rect1 extends Applet {

  public void paint (Graphics g) {
    g.drawRect (x, y, width, height);    //can use either of the two//
    g.fillRect (x, y, width, height);
    g.setColor(color);
  }

}

where x is x co-ordinate y is y cordinate color=the color you want to use eg Color.blue

if you want to use rectangle object you could do it like this:

import java.applet.Applet;
import java.awt.*;

public class Rect1 extends Applet {

  public void paint (Graphics g) {    
    Rectangle r = new Rectangle(arg,arg1,arg2,arg3);
    g.fillRect(r.getX(), r.getY(), r.getWidth(), r.getHeight());
    g.setColor(color);
  }
}       

How to Decode Json object in laravel and apply foreach loop on that in laravel

your string is NOT a valid json to start with.

a valid json will be,

{
    "area": [
        {
            "area": "kothrud"
        },
        {
            "area": "katraj"
        }
    ]
}

if you do a json_decode, it will yield,

stdClass Object
(
    [area] => Array
        (
            [0] => stdClass Object
                (
                    [area] => kothrud
                )

            [1] => stdClass Object
                (
                    [area] => katraj
                )

        )

)

Update: to use

$string = '

{
    "area": [
        {
            "area": "kothrud"
        },
        {
            "area": "katraj"
        }
    ]
}

';
            $area = json_decode($string, true);

            foreach($area['area'] as $i => $v)
            {
                echo $v['area'].'<br/>';
            }

Output:

kothrud
katraj

Update #2:

for that true:

When TRUE, returned objects will be converted into associative arrays. for more information, click here

what's the correct way to send a file from REST web service to client?

I don't recommend encoding binary data in base64 and wrapping it in JSON. It will just needlessly increase the size of the response and slow things down.

Simply serve your file data using GET and application/octect-streamusing one of the factory methods of javax.ws.rs.core.Response (part of the JAX-RS API, so you're not locked into Jersey):

@GET
@Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response getFile() {
  File file = ... // Initialize this to the File path you want to serve.
  return Response.ok(file, MediaType.APPLICATION_OCTET_STREAM)
      .header("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"" ) //optional
      .build();
}

If you don't have an actual File object, but an InputStream, Response.ok(entity, mediaType) should be able to handle that as well.

How to delete columns in pyspark dataframe

An easy way to do this is to user "select" and realize you can get a list of all columns for the dataframe, df, with df.columns

drop_list = ['a column', 'another column', ...]

df.select([column for column in df.columns if column not in drop_list])

How to convert a string of numbers to an array of numbers?

+string will try to change the string to a number. Then use Array.map function to change every element.

"1,2,3,4".split(',').map(function(el){ return +el;});

Get paragraph text inside an element

Try this:

<li onclick="myfunction(this)">

function myfunction(li) {
    var TextInsideLi = li.getElementsByTagName('p')[0].innerHTML;
}

Live demo

How do I make a batch file terminate upon encountering an error?

We cannot always depend on ERRORLEVEL, because many times external programs or batch scripts do not return exit codes.

In that case we can use generic checks for failures like this:

IF EXIST %outfile% (DEL /F %outfile%)
CALL some_script.bat -o %outfile%
IF NOT EXIST %outfile%  (ECHO ERROR & EXIT /b)

And if the program outputs something to console, we can check it also.

some_program.exe 2>&1 | FIND "error message here" && (ECHO ERROR & EXIT /b)
some_program.exe 2>&1 | FIND "Done processing." || (ECHO ERROR & EXIT /b)

Can I scroll a ScrollView programmatically in Android?

There are a lot of good answers here, but I only want to add one thing. It sometimes happens that you want to scroll your ScrollView to a specific view of the layout, instead of a full scroll to the top or the bottom.

A simple example: in a registration form, if the user tap the "Signup" button when a edit text of the form is not filled, you want to scroll to that specific edit text to tell the user that he must fill that field.

In that case, you can do something like that:

scrollView.post(new Runnable() { 
        public void run() { 
             scrollView.scrollTo(0, editText.getBottom());
        } 
});

or, if you want a smooth scroll instead of an instant scroll:

scrollView.post(new Runnable() { 
            public void run() { 
                 scrollView.smoothScrollTo(0, editText.getBottom());
            } 
    });

Obviously you can use any type of view instead of Edit Text. Note that getBottom() returns the coordinates of the view based on its parent layout, so all the views used inside the ScrollView should have only a parent (for example a Linear Layout).

If you have multiple parents inside the child of the ScrollView, the only solution i've found is to call requestChildFocus on the parent view:

editText.getParent().requestChildFocus(editText, editText);

but in this case you cannot have a smooth scroll.

I hope this answer can help someone with the same problem.

JavaScript OR (||) variable assignment explanation

See short-circuit evaluation for the explanation. It's a common way of implementing these operators; it is not unique to JavaScript.

change cursor from block or rectangle to line?

please Press fn +ins key together

How to pause for specific amount of time? (Excel/VBA)

Just a cleaned up version of clemo's code - works in Access, which doesn't have the Application.Wait function.

Public Sub Pause(sngSecs As Single)
    Dim sngEnd As Single
    sngEnd = Timer + sngSecs
    While Timer < sngEnd
        DoEvents
    Wend
End Sub

Public Sub TestPause()
    Pause 1
    MsgBox "done"
End Sub

BeautifulSoup: extract text from anchor tag

>>> txt = '<a class="title" href="http://rads.stackoverflow.com/amzn/click/B0073HSK0K">Nikon COOLPIX L26 16.1 MP Digital Camera with 5x Zoom NIKKOR Glass Lens and 3-inch LCD (Red)</a> '
>>> fragment = bs4.BeautifulSoup(txt)
>>> fragment
<a class="title" href="http://rads.stackoverflow.com/amzn/click/B0073HSK0K">Nikon COOLPIX L26 16.1 MP Digital Camera with 5x Zoom NIKKOR Glass Lens and 3-inch LCD (Red)</a> 
>>> fragment.find('a', {'class': 'title'})
<a class="title" href="http://rads.stackoverflow.com/amzn/click/B0073HSK0K">Nikon COOLPIX L26 16.1 MP Digital Camera with 5x Zoom NIKKOR Glass Lens and 3-inch LCD (Red)</a>
>>> fragment.find('a', {'class': 'title'}).string
u'Nikon COOLPIX L26 16.1 MP Digital Camera with 5x Zoom NIKKOR Glass Lens and 3-inch LCD (Red)'

Convert float to double without losing precision

I found the following solution:

public static Double getFloatAsDouble(Float fValue) {
    return Double.valueOf(fValue.toString());
}

If you use float and double instead of Float and Double use the following:

public static double getFloatAsDouble(float value) {
    return Double.valueOf(Float.valueOf(value).toString()).doubleValue();
}

How to fade changing background image

This is probably what you wanted:

$('#elem').fadeTo('slow', 0.3, function()
{
    $(this).css('background-image', 'url(' + $img + ')');
}).fadeTo('slow', 1);

With a 1 second delay:

$('#elem').fadeTo('slow', 0.3, function()
{
    $(this).css('background-image', 'url(' + $img + ')');
}).delay(1000).fadeTo('slow', 1);

how to set JAVA_OPTS for Tomcat in Windows?

SET JAVA_HOME=C:\Applications\java\java_8
SET PATH=%PATH%;C:\Applications\java\java_8\bin
SET JAVA_OPTIONS=-d64 -Xms128g -Xmx128g

How can I drop a "not null" constraint in Oracle when I don't know the name of the constraint?

alter table MYTABLE modify (MYCOLUMN null);

In Oracle, not null constraints are created automatically when not null is specified for a column. Likewise, they are dropped automatically when the column is changed to allow nulls.

Clarifying the revised question: This solution only applies to constraints created for "not null" columns. If you specify "Primary Key" or a check constraint in the column definition without naming it, you'll end up with a system-generated name for the constraint (and the index, for the primary key). In those cases, you'd need to know the name to drop it. The best advice there is to avoid the scenario by making sure you specify a name for all constraints other than "not null". If you find yourself in the situation where you need to drop one of these constraints generically, you'll probably need to resort to PL/SQL and the data-definition tables.

How to return dictionary keys as a list in Python?

A bit off on the "duck typing" definition -- dict.keys() returns an iterable object, not a list-like object. It will work anywhere an iterable will work -- not any place a list will. a list is also an iterable, but an iterable is NOT a list (or sequence...)

In real use-cases, the most common thing to do with the keys in a dict is to iterate through them, so this makes sense. And if you do need them as a list you can call list().

Very similarly for zip() -- in the vast majority of cases, it is iterated through -- why create an entire new list of tuples just to iterate through it and then throw it away again?

This is part of a large trend in python to use more iterators (and generators), rather than copies of lists all over the place.

dict.keys() should work with comprehensions, though -- check carefully for typos or something... it works fine for me:

>>> d = dict(zip(['Sounder V Depth, F', 'Vessel Latitude, Degrees-Minutes'], [None, None]))
>>> [key.split(", ") for key in d.keys()]
[['Sounder V Depth', 'F'], ['Vessel Latitude', 'Degrees-Minutes']]

Update React component every second

So you were on the right track. Inside your componentDidMount() you could have finished the job by implementing setInterval() to trigger the change, but remember the way to update a components state is via setState(), so inside your componentDidMount() you could have done this:

componentDidMount() {
  setInterval(() => {
   this.setState({time: Date.now()})    
  }, 1000)
}

Also, you use Date.now() which works, with the componentDidMount() implementation I offered above, but you will get a long set of nasty numbers updating that is not human readable, but it is technically the time updating every second in milliseconds since January 1, 1970, but we want to make this time readable to how we humans read time, so in addition to learning and implementing setInterval you want to learn about new Date() and toLocaleTimeString() and you would implement it like so:

class TimeComponent extends Component {
  state = { time: new Date().toLocaleTimeString() };
}

componentDidMount() {
  setInterval(() => {
   this.setState({ time: new Date().toLocaleTimeString() })    
  }, 1000)
}

Notice I also removed the constructor() function, you do not necessarily need it, my refactor is 100% equivalent to initializing site with the constructor() function.

How to reset the bootstrap modal when it gets closed and open it fresh again?

(function(){
        $(".modal").on("hidden.bs.modal", function(){
            $(this).removeData();
        });
});

This is perfect solution to remove contact while hide/close bootstrap modal.

Creating stored procedure and SQLite?

Yet, it is possible to fake it using a dedicated table, named for your fake-sp, with an AFTER INSERT trigger. The dedicated table rows contain the parameters for your fake sp, and if it needs to return results you can have a second (poss. temp) table (with name related to the fake-sp) to contain those results. It would require two queries: first to INSERT data into the fake-sp-trigger-table, and the second to SELECT from the fake-sp-results-table, which could be empty, or have a message-field if something went wrong.

Flask-SQLalchemy update a row's information

This does not work if you modify a pickled attribute of the model. Pickled attributes should be replaced in order to trigger updates:

from flask import Flask
from flask.ext.sqlalchemy import SQLAlchemy
from pprint import pprint

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqllite:////tmp/users.db'
db = SQLAlchemy(app)


class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(80), unique=True)
    data = db.Column(db.PickleType())

    def __init__(self, name, data):
        self.name = name
        self.data = data

    def __repr__(self):
        return '<User %r>' % self.username

db.create_all()

# Create a user.
bob = User('Bob', {})
db.session.add(bob)
db.session.commit()

# Retrieve the row by its name.
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {}

# Modifying data is ignored.
bob.data['foo'] = 123
db.session.commit()
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {}

# Replacing data is respected.
bob.data = {'bar': 321}
db.session.commit()
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {'bar': 321}

# Modifying data is ignored.
bob.data['moo'] = 789
db.session.commit()
bob = User.query.filter_by(name='Bob').first()
pprint(bob.data)  # {'bar': 321}

What is the difference between declarative and imperative paradigm in programming?

Just to add another example in terms of mobile app development. In iOS and Android, we have Interface Builders, where we can define UI of the apps.

The UI drawn using these Builders is declarative in nature, where we drag and drop the components. The actual drawing happens underneath and performed by the framework and system.

But we can also draw the whole components in code, and that is imperative in nature.

Also, some new languages like Angular JS are focussing on designing UIs declaratively and we may see a lot of other languages offering the same support. Like Java doesn't have any good declarative way to draw native desktop apps in Java swing or Java FX but in the near future, they just might.

two divs the same line, one dynamic width, one fixed

So left div style depends on the presence of right div. I can't think of a CSS selector allowing that kind of behavior yet.

Thus it seems to me that you'll need to programmatically add a class server side (or in JS) on parent div or left div to do that.

<div id="parent twocols">
  <div class="left"></div>
  <div class="right"></div>
</div>

or

<div id="parent">
  <div class="left"></div>
</div>

So right style is always :

.right {
    float: right;
    width: 200px; /* or whatever value you need */
    /* margin and padding at your discretion */
}

and left style is :

.parent.twocols .left {
    margin-right: 200px; /* according to right div width + margin + padding*/
}

How to load a jar file at runtime

Reloading existing classes with existing data is likely to break things.

You can load new code into new class loaders relatively easily:

ClassLoader loader = URLClassLoader.newInstance(
    new URL[] { yourURL },
    getClass().getClassLoader()
);
Class<?> clazz = Class.forName("mypackage.MyClass", true, loader);
Class<? extends Runnable> runClass = clazz.asSubclass(Runnable.class);
// Avoid Class.newInstance, for it is evil.
Constructor<? extends Runnable> ctor = runClass.getConstructor();
Runnable doRun = ctor.newInstance();
doRun.run();

Class loaders no longer used can be garbage collected (unless there is a memory leak, as is often the case with using ThreadLocal, JDBC drivers, java.beans, etc).

If you want to keep the object data, then I suggest a persistence mechanism such as Serialisation, or whatever you are used to.

Of course debugging systems can do fancier things, but are more hacky and less reliable.

It is possible to add new classes into a class loader. For instance, using URLClassLoader.addURL. However, if a class fails to load (because, say, you haven't added it), then it will never load in that class loader instance.

Difference between int and double

Short answer:

int uses up 4 bytes of memory (and it CANNOT contain a decimal), double uses 8 bytes of memory. Just different tools for different purposes.

How can I check if an element exists in the visible DOM?

From Mozilla Developer Network:

This function checks to see if an element is in the page's body. As contains() is inclusive and determining if the body contains itself isn't the intention of isInPage, this case explicitly returns false.

function isInPage(node) {
  return (node === document.body) ? false : document.body.contains(node);
}

node is the node we want to check for in the <body>.

When and how should I use a ThreadLocal variable?

There are 3 scenarios for using a class helper like SimpleDateFormat in multithread code, which best one is use ThreadLocal

Scenarios

1- Using like share object by the help of lock or synchronization mechanism which makes the app slow

2- Using as a local object inside a method

In this scenario, if we have 4 thread each one calls a method 1000 time then we have
4000 SimpleDateFormat object created and waiting for GC to erase them

3- Using ThreadLocal

if we have 4 thread and we gave to each thread one SimpleDateFormat instance
so we have 4 threads, 4 objects of SimpleDateFormat.

There is no need of lock mechanism and object creation and destruction. (Good time complexity and space complexity)

Integer value in TextView

Alternative approach:

 TextView tv = new TextView(this);
 tv.setText(Integer.toString(integer));

How to lowercase a pandas dataframe string column if it has missing values?

use pandas vectorized string methods; as in the documentation:

these methods exclude missing/NA values automatically

.str.lower() is the very first example there;

>>> df['x'].str.lower()
0    one
1    two
2    NaN
Name: x, dtype: object

How to find char in string and get all the indexes?

This is slightly modified version of Mark Ransom's answer that works if ch could be more than one character in length.

def find(term, ch):
    """Find all places with ch in str
    """
    for i in range(len(term)):
        if term[i:i + len(ch)] == ch:
            yield i

Entityframework Join using join method and lambdas

If you have configured navigation property 1-n I would recommend you to use:

var query = db.Categories                                  // source
   .SelectMany(c=>c.CategoryMaps,                          // join
      (c, cm) => new { Category = c, CategoryMaps = cm })  // project result
   .Select(x => x.Category);                               // select result

Much more clearer to me and looks better with multiple nested joins.

How to change button text or link text in JavaScript?

You can simply use:

document.getElementById(button_id).innerText = 'Your text here';

If you want to use HTML formatting, use the innerHTML property instead.

Adding a column to an existing table in a Rails migration

Use this command at rails console

rails generate migration add_fieldname_to_tablename fieldname:string

and

rake db:migrate

to run this migration

Difference between JE/JNE and JZ/JNZ

From the Intel's manual - Instruction Set Reference, the JE and JZ have the same opcode (74 for rel8 / 0F 84 for rel 16/32) also JNE and JNZ (75 for rel8 / 0F 85 for rel 16/32) share opcodes.

JE and JZ they both check for the ZF (or zero flag), although the manual differs slightly in the descriptions of the first JE rel8 and JZ rel8 ZF usage, but basically they are the same.

Here is an extract from the manual's pages 464, 465 and 467.

 Op Code    | mnemonic  | Description
 -----------|-----------|-----------------------------------------------  
 74 cb      | JE rel8   | Jump short if equal (ZF=1).
 74 cb      | JZ rel8   | Jump short if zero (ZF ? 1).

 0F 84 cw   | JE rel16  | Jump near if equal (ZF=1). Not supported in 64-bit mode.
 0F 84 cw   | JZ rel16  | Jump near if 0 (ZF=1). Not supported in 64-bit mode.

 0F 84 cd   | JE rel32  | Jump near if equal (ZF=1).
 0F 84 cd   | JZ rel32  | Jump near if 0 (ZF=1).

 75 cb      | JNE rel8  | Jump short if not equal (ZF=0).
 75 cb      | JNZ rel8  | Jump short if not zero (ZF=0).

 0F 85 cd   | JNE rel32 | Jump near if not equal (ZF=0).
 0F 85 cd   | JNZ rel32 | Jump near if not zero (ZF=0).

Multiple file upload in php

Simple is that, just count the files array first, then in while loop you can easily do this like

$count = count($_FILES{'item_file']['name']);

now you got total number of files right.

In while loop do like this:

$i = 0;
while($i<$count)
{
    Upload one by one like we do normally
    $i++;
}

How to reference a method in javadoc?

You will find much information about JavaDoc at the Documentation Comment Specification for the Standard Doclet, including the information on the

{@link package.class#member label}

tag (that you are looking for). The corresponding example from the documentation is as follows

For example, here is a comment that refers to the getComponentAt(int, int) method:

Use the {@link #getComponentAt(int, int) getComponentAt} method.

The package.class part can be ommited if the referred method is in the current class.


Other useful links about JavaDoc are:

How do you get a query string on Flask?

from flask import request

@app.route('/data')
def data():
    # here we want to get the value of user (i.e. ?user=some-value)
    user = request.args.get('user')

How to write a std::string to a UTF-8 text file

What is the easiest and simple way to do so?

The most intuitive and thus easiest handling of utf8 in C++ is for sure using a drop-in replacement for std::string. As the internet still lacks of one, I went to implement the functionality on my own:

tinyutf8 (EDIT: now Github).

This library provides a very lightweight drop-in preplacement for std::string (or std::u32string if you will, because you iterate over codepoints rather that chars). Ity is implemented succesfully in the middle between fast access and small memory consumption, while being very robust. This robustness to 'invalid' UTF8-sequences makes it (nearly completely) compatible with ANSI (0-255).

Hope this helps!

Get all validation errors from Angular 2 FormGroup

This is solution with FormGroup inside supports ( like here )

Tested on: Angular 4.3.6

get-form-validation-errors.ts

import { AbstractControl, FormGroup, ValidationErrors } from '@angular/forms';

export interface AllValidationErrors {
  control_name: string;
  error_name: string;
  error_value: any;
}

export interface FormGroupControls {
  [key: string]: AbstractControl;
}

export function getFormValidationErrors(controls: FormGroupControls): AllValidationErrors[] {
  let errors: AllValidationErrors[] = [];
  Object.keys(controls).forEach(key => {
    const control = controls[ key ];
    if (control instanceof FormGroup) {
      errors = errors.concat(getFormValidationErrors(control.controls));
    }
    const controlErrors: ValidationErrors = controls[ key ].errors;
    if (controlErrors !== null) {
      Object.keys(controlErrors).forEach(keyError => {
        errors.push({
          control_name: key,
          error_name: keyError,
          error_value: controlErrors[ keyError ]
        });
      });
    }
  });
  return errors;
}

Using example:

if (!this.formValid()) {
  const error: AllValidationErrors = getFormValidationErrors(this.regForm.controls).shift();
  if (error) {
    let text;
    switch (error.error_name) {
      case 'required': text = `${error.control_name} is required!`; break;
      case 'pattern': text = `${error.control_name} has wrong pattern!`; break;
      case 'email': text = `${error.control_name} has wrong email format!`; break;
      case 'minlength': text = `${error.control_name} has wrong length! Required length: ${error.error_value.requiredLength}`; break;
      case 'areEqual': text = `${error.control_name} must be equal!`; break;
      default: text = `${error.control_name}: ${error.error_name}: ${error.error_value}`;
    }
    this.error = text;
  }
  return;
}

C# : assign data to properties via constructor vs. instantiating

Object initializers are cool because they allow you to set up a class inline. The tradeoff is that your class cannot be immutable. Consider:

public class Album 
{
    // Note that we make the setter 'private'
    public string Name { get; private set; }
    public string Artist { get; private set; }
    public int Year { get; private set; }

    public Album(string name, string artist, int year)
    {
        this.Name = name;
        this.Artist = artist;
        this.Year = year;
    }
}

If the class is defined this way, it means that there isn't really an easy way to modify the contents of the class after it has been constructed. Immutability has benefits. When something is immutable, it is MUCH easier to determine that it's correct. After all, if it can't be modified after construction, then there is no way for it to ever be 'wrong' (once you've determined that it's structure is correct). When you create anonymous classes, such as:

new { 
    Name = "Some Name",
    Artist = "Some Artist",
    Year = 1994
};

the compiler will automatically create an immutable class (that is, anonymous classes cannot be modified after construction), because immutability is just that useful. Most C++/Java style guides often encourage making members const(C++) or final (Java) for just this reason. Bigger applications are just much easier to verify when there are fewer moving parts.

That all being said, there are situations when you want to be able quickly modify the structure of your class. Let's say I have a tool that I want to set up:

public void Configure(ConfigurationSetup setup);

and I have a class that has a number of members such as:

class ConfigurationSetup {
    public String Name { get; set; }
    public String Location { get; set; }
    public Int32 Size { get; set; }
    public DateTime Time { get; set; }

    // ... and some other configuration stuff... 
}

Using object initializer syntax is useful when I want to configure some combination of properties, but not neccesarily all of them at once. For example if I just want to configure the Name and Location, I can just do:

ConfigurationSetup setup = new ConfigurationSetup {
    Name = "Some Name",
    Location = "San Jose"
};

and this allows me to set up some combination without having to define a new constructor for every possibly permutation.

On the whole, I would argue that making your classes immutable will save you a great deal of development time in the long run, but having object initializer syntax makes setting up certain configuration permutations much easier.

Cannot connect to SQL Server named instance from another SQL Server

To solve this you must ensure the following is true on the machine hosting SQL Server...

  1. Ensure Server Browser service is running
  2. Ensure TCP/IP communication is enabled for each instance you wish to communicate with over the network. enter image description here
  3. If running multiple instances, ensure each instance is using a different port, and that the port is not in use. e.g for two instance 1433 (default port for the default instance, 1435 for a named instance. enter image description here
  4. Ensure the firewall has an entry to allow communication with SQL Server browser on port 1434 over the UDP protocol.
  5. Ensure the firewall has an entry to allow communication with SQL Server instances on the ports assigned to them in step 3 over the TCP protocol enter image description here

Get Android Device Name

You can see answers at here Get Android Phone Model Programmatically

public String getDeviceName() {
   String manufacturer = Build.MANUFACTURER;
   String model = Build.MODEL;
   if (model.startsWith(manufacturer)) {
      return capitalize(model);
   } else {
      return capitalize(manufacturer) + " " + model;
   }
}


private String capitalize(String s) {
    if (s == null || s.length() == 0) {
        return "";
    }
    char first = s.charAt(0);
    if (Character.isUpperCase(first)) {
        return s;
    } else {
        return Character.toUpperCase(first) + s.substring(1);
    }
}

Git: Recover deleted (remote) branch

just two commands save my life

1. This will list down all previous HEADs

git reflog

2. This will revert the HEAD to commit that you deleted.

git reset --hard <your deleted commit>
ex. git reset --hard b4b2c02

How to add a footer in ListView?

I know this is a very old question, but I googled my way here and found the answer provided not 100% satisfying, because as gcl1 mentioned - this way the footer is not really a footer to the screen - it's just an "add-on" to the list.

Bottom line - for others who may google their way here - I found the following suggestion here: Fixed and always visible footer below ListFragment

Try doing as follows, where the emphasis is on the button (or any footer element) listed first in the XML - and then the list is added as "layout_above":

<RelativeLayout>

<Button android:id="@+id/footer" android:layout_alignParentBottom="true"/> 
<ListView android:id="@android:id/list" **android:layout_above**="@id/footer"> <!-- the list -->

</RelativeLayout>

Laravel: getting a a single value from a MySQL query

Edit:

Sorry i forgot about pluck() as many have commented : Easiest way is :

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

Which will directly return the only the first result for the requested row as a string.

Using the fluent query builder you will obtain an array anyway. I mean The Query Builder has no idea how many rows will come back from that query. Here is what you can do to do it a bit cleaner

$result = DB::table('users')->select('groupName')->where('username', $username)->first();

The first() tells the queryBuilder to return only one row so no array, so you can do :

return $result->groupName;

Hope it helps

initialize a const array in a class initializer in C++

It is not possible in the current standard. I believe you'll be able to do this in C++0x using initializer lists (see A Brief Look at C++0x, by Bjarne Stroustrup, for more information about initializer lists and other nice C++0x features).

ie8 var w= window.open() - "Message: Invalid argument."

I discovered the same problem and after reading the first answer that supposed the problem is caused by the window name, changed it : first to '_blank', which worked fine (both compatibility and regular view), then to the previous value, only minus the space in the value :) - also worked. IMO, the problem (or part of it) is caused by IE being unable to use a normal string value as the wname. Hope this helps if anybody runs into the same problem.

how to align img inside the div to the right?

<style type="text/css">
>> .imgTop {
>>  display: block;
>>  text-align: right;
>>  }
>> </style>

<img class="imgTop" src="imgName.gif" alt="image description" height="100" width="100">

See changes to a specific file using git

You can use below command to see who have changed what in a file.

git blame <filename>

Update Fragment from ViewPager

A very simple yet effective solution to update your fragment views. Use setUserVisibleHint() method. It will be called upon when the fragment is about to be visible to user. There you can update our view (setText() or setVisibility() etc.)

@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);

    if(isVisibleToUser){
       //Write your code to be executed when it is visible to user
    }
}

It worked in my case. Hope it helps!

How to remove from a map while iterating it?

The standard associative-container erase idiom:

for (auto it = m.cbegin(); it != m.cend() /* not hoisted */; /* no increment */)
{
  if (must_delete)
  {
    m.erase(it++);    // or "it = m.erase(it)" since C++11
  }
  else
  {
    ++it;
  }
}

Note that we really want an ordinary for loop here, since we are modifying the container itself. The range-based loop should be strictly reserved for situations where we only care about the elements. The syntax for the RBFL makes this clear by not even exposing the container inside the loop body.

Edit. Pre-C++11, you could not erase const-iterators. There you would have to say:

for (std::map<K,V>::iterator it = m.begin(); it != m.end(); ) { /* ... */ }

Erasing an element from a container is not at odds with constness of the element. By analogy, it has always been perfectly legitimate to delete p where p is a pointer-to-constant. Constness does not constrain lifetime; const values in C++ can still stop existing.

Rownum in postgresql

Postgresql does not have an equivalent of Oracle's ROWNUM. In many cases you can achieve the same result by using LIMIT and OFFSET in your query.

Sending POST data without form

have a look at the php documentation for theese functions you can send post reqeust using them.

fsockopen()
fputs()

or simply use a class like Zend_Http_Client which is also based on socket-conenctions.

also found a neat example using google...

How to scanf only integer and repeat reading if the user enters non-numeric characters?

You will need to repeat your call to strtol inside your loops where you are asking the user to try again. In fact, if you make the loop a do { ... } while(...); instead of while, you don't get a the same sort of repeat things twice behaviour.

You should also format your code so that it's possible to see where the code is inside a loop and not.

Write in body request with HttpClient

If your xml is written by java.lang.String you can just using HttpClient in this way

    public void post() throws Exception{
        HttpClient client = new DefaultHttpClient();
        HttpPost post = new HttpPost("http://www.baidu.com");
        String xml = "<xml>xxxx</xml>";
        HttpEntity entity = new ByteArrayEntity(xml.getBytes("UTF-8"));
        post.setEntity(entity);
        HttpResponse response = client.execute(post);
        String result = EntityUtils.toString(response.getEntity());
    }

pay attention to the Exceptions.

BTW, the example is written by the httpclient version 4.x

Difference between "this" and"super" keywords in Java

this is used to access the methods and fields of the current object. For this reason, it has no meaning in static methods, for example.

super allows access to non-private methods and fields in the super-class, and to access constructors from within the class' constructors only.

Binding an Image in WPF MVVM

If you have a process that already generates and returns an Image type, you can alter the bind and not have to modify any additional image creation code.

Refer to the ".Source" of the image in the binding statement.

XAML

<Image Name="imgOpenClose" Source="{Binding ImageOpenClose.Source}"/>

View Model Field

private Image _imageOpenClose;
public Image ImageOpenClose
{
    get
    {
        return _imageOpenClose;
    }
    set
    {
        _imageOpenClose = value;
        OnPropertyChanged();
    }
}

What is the error "Every derived table must have its own alias" in MySQL?

Here's a different example that can't be rewritten without aliases ( can't GROUP BY DISTINCT).

Imagine a table called purchases that records purchases made by customers at stores, i.e. it's a many to many table and the software needs to know which customers have made purchases at more than one store:

SELECT DISTINCT customer_id, SUM(1)
  FROM ( SELECT DISTINCT customer_id, store_id FROM purchases)
  GROUP BY customer_id HAVING 1 < SUM(1);

..will break with the error Every derived table must have its own alias. To fix:

SELECT DISTINCT customer_id, SUM(1)
  FROM ( SELECT DISTINCT customer_id, store_id FROM purchases) AS custom
  GROUP BY customer_id HAVING 1 < SUM(1);

( Note the AS custom alias).

Not receiving Google OAuth refresh token

Using offline access and prompt:consent worked well to me:

   auth2 = gapi.auth2.init({
                    client_id: '{cliend_id}' 
   });

   auth2.grantOfflineAccess({prompt:'consent'}).then(signInCallback); 

Try-catch-finally-return clarification

If the return in the try block is reached, it transfers control to the finally block, and the function eventually returns normally (not a throw).

If an exception occurs, but then the code reaches a return from the catch block, control is transferred to the finally block and the function eventually returns normally (not a throw).

In your example, you have a return in the finally, and so regardless of what happens, the function will return 34, because finally has the final (if you will) word.

Although not covered in your example, this would be true even if you didn't have the catch and if an exception were thrown in the try block and not caught. By doing a return from the finally block, you suppress the exception entirely. Consider:

public class FinallyReturn {
  public static final void main(String[] args) {
    System.out.println(foo(args));
  }

  private static int foo(String[] args) {
    try {
      int n = Integer.parseInt(args[0]);
      return n;
    }
    finally {
      return 42;
    }
  }
}

If you run that without supplying any arguments:

$ java FinallyReturn

...the code in foo throws an ArrayIndexOutOfBoundsException. But because the finally block does a return, that exception gets suppressed.

This is one reason why it's best to avoid using return in finally.

Mergesort with Python

Loops like this can probably be speeded up:

for i in z:
    result.append(i)
    z.pop(0)

Instead, simply do this:

result.extend(z)

Note that there is no need to clean the contents of z because you won't use it anyway.

How to take backup of a single table in a MySQL database?

You can use this code:

This example takes a backup of sugarcrm database and dumps the output to sugarcrm.sql

# mysqldump -u root -ptmppassword sugarcrm > sugarcrm.sql

# mysqldump -u root -p[root_password] [database_name] > dumpfilename.sql

The sugarcrm.sql will contain drop table, create table and insert command for all the tables in the sugarcrm database. Following is a partial output of sugarcrm.sql, showing the dump information of accounts_contacts table:

--

-- Table structure for table accounts_contacts

DROP TABLE IF EXISTS `accounts_contacts`;
SET @saved_cs_client = @@character_set_client;
SET character_set_client = utf8;
CREATE TABLE `accounts_contacts` (
`id` varchar(36) NOT NULL,
`contact_id` varchar(36) default NULL,
`account_id` varchar(36) default NULL,
`date_modified` datetime default NULL,
`deleted` tinyint(1) NOT NULL default '0',
PRIMARY KEY (`id`),
KEY `idx_account_contact` (`account_id`,`contact_id`),
KEY `idx_contid_del_accid` (`contact_id`,`deleted`,`account_id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
SET character_set_client = @saved_cs_client;

--

Android: Color To Int conversion

R.color.black or some color are obviously integers. It needs a RGB value. You can give your own like #FF123454 which represents various primary colors

Which characters are valid in CSS class names/selectors?

I’ve answered your question in-depth here: http://mathiasbynens.be/notes/css-escapes

The article also explains how to escape any character in CSS (and JavaScript), and I made a handy tool for this as well. From that page:

If you were to give an element an ID value of ~!@$%^&*()_+-=,./';:"?><[]{}|`#, the selector would look like this:

CSS:

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

JavaScript:

<script>
  // document.getElementById or similar
  document.getElementById('~!@$%^&*()_+-=,./\';:"?><[]\\{}|`#');
  // document.querySelector or similar
  $('#\\~\\!\\@\\$\\%\\^\\&\\*\\(\\)\\_\\+-\\=\\,\\.\\/\\\'\\;\\:\\"\\?\\>\\<\\[\\]\\\\\\{\\}\\|\\`\\#');
</script>

How do I get the total number of unique pairs of a set in the database?

This is how you can approach these problems in general on your own:

The first of the pair can be picked in N (=100) ways. You don't want to pick this item again, so the second of the pair can be picked in N-1 (=99) ways. In total you can pick 2 items out of N in N(N-1) (= 100*99=9900) different ways.

But hold on, this way you count also different orderings: AB and BA are both counted. Since every pair is counted twice you have to divide N(N-1) by two (the number of ways that you can order a list of two items). The number of subsets of two that you can make with a set of N is then N(N-1)/2 (= 9900/2 = 4950).

How to fix "set SameSite cookie to none" warning?

I am using both JavaScript Cookie and Java CookieUtil in my project, below settings solved my problem:

JavaScript Cookie

var d = new Date();
d.setTime(d.getTime() + (30*24*60*60*1000)); //keep cookie 30 days
var expires = "expires=" + d.toGMTString();         
document.cookie = "visitName" + "=Hailin;" + expires + ";path=/;SameSite=None;Secure"; //can set SameSite=Lax also

JAVA Cookie (set proxy_cookie_path in Nginx)

location / {
   proxy_pass http://96.xx.xx.34;
   proxy_intercept_errors on;
   #can set SameSite=None also
   proxy_cookie_path / "/;SameSite=Lax;secure";
   proxy_connect_timeout 600;
   proxy_read_timeout 600;
}

Check result in Firefox enter image description here

Read more on https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite

Android - Activity vs FragmentActivity?

ianhanniballake is right. You can get all the functionality of Activity from FragmentActivity. In fact, FragmentActivity has more functionality.

Using FragmentActivity you can easily build tab and swap format. For each tab you can use different Fragment (Fragments are reusable). So for any FragmentActivity you can reuse the same Fragment.

Still you can use Activity for single pages like list down something and edit element of the list in next page.

Also remember to use Activity if you are using android.app.Fragment; use FragmentActivity if you are using android.support.v4.app.Fragment. Never attach a android.support.v4.app.Fragment to an android.app.Activity, as this will cause an exception to be thrown.

Laravel is there a way to add values to a request array

Based on my observations:

$request->request->add(['variable' => 'value']); will (mostly) work in POST, PUT & DELETE methods, because there is value(s) passed, one of those is _token. Like example below.

<form action="{{ route('process', $id) }}" method="POST">
    @csrf
</form>

public function process(Request $request, $id){
    $request->request->add(['id' => $id]);
}

But [below code] won't work because there is no value(s) passed, it doesn't really add.

<a href='{{ route('process', $id) }}'>PROCESS</a>

public function process(Request $request, $id){
    $request->request->add(['id' => $id]);
}


When using GET method you can either declare Request and assign value(s) on it directly. Like below:

public function process($id){
    $request = new Request(['id' => $id]);
}

Or you can use merge. This is better actually than $request->request->add(['variable' => 'value']); because can initialize, and add request values that will work for all methods (GET, POST, PUT, DELETE)

public function process(Request $request, $id){
    $request->merge(['id' => $id]);
}

Tag: laravel5.8.11

Wordpress keeps redirecting to install-php after migration

This happens due to the following issues:

  1. Missing Files
  2. Database Connection Details Problem
  3. Site URL Issue
  4. .htaccess File Issue
  5. Webserver Failure
  6. Resources Blocked by Plugin
  7. Query Limit Exceeded
  8. Insufficient Database Privileges
  9. PHP Extensions

Reference: https://www.scratchcode.io/wordpress-keeps-redirecting-to-wp-admin-install-php/

Setting java locale settings

I had to control this in a script that ran on a machine with French locale, but a specific Java program had to run with en_US. As already pointed out, the following works:

java -Duser.language=en -Duser.country=US ...

Alternatively,

LC_ALL=en_US.UTF-8 java ...

I prefer the latter.

What is Linux’s native GUI API?

Strictly speaking, the API of Linux consists of its system calls. These are all of the kernel functions that can be called by a user-mode (non-kernel) program. This is a very low-level interface that allows programs to do things like open and read files. See http://en.wikipedia.org/wiki/System_call for a general introduction.

A real Linux system will also have an entire "stack" of other software running on it, in order to provide a graphical user interface and other features. Each element of this stack will offer its own API.

Adding machineKey to web.config on web-farm sites

If you are using IIS 7.5 or later you can generate the machine key from IIS and save it directly to your web.config, within the web farm you then just copy the new web.config to each server.

  1. Open IIS manager.
  2. If you need to generate and save the MachineKey for all your applications select the server name in the left pane, in that case you will be modifying the root web.config file (which is placed in the .NET framework folder). If your intention is to create MachineKey for a specific web site/application then select the web site / application from the left pane. In that case you will be modifying the web.config file of your application.
  3. Double-click the Machine Key icon in ASP.NET settings in the middle pane:
  4. MachineKey section will be read from your configuration file and be shown in the UI. If you did not configure a specific MachineKey and it is generated automatically you will see the following options:
  5. Now you can click Generate Keys on the right pane to generate random MachineKeys. When you click Apply, all settings will be saved in the web.config file.

Full Details can be seen @ Easiest way to generate MachineKey – Tips and tricks: ASP.NET, IIS and .NET development…

How do I make flex box work in safari?

I had to add the webkit prefix for safari (but flex not flexbox):

display:-webkit-flex

Transform char array into String

I have search it again and search this question in baidu. Then I find 2 ways:

1,

_x000D_
_x000D_
char ch[]={'a','b','c','d','e','f','g','\0'};_x000D_
string s=ch;_x000D_
cout<<s;
_x000D_
_x000D_
_x000D_

Be aware to that '\0' is necessary for char array ch.

2,

_x000D_
_x000D_
#include<iostream>_x000D_
#include<string>_x000D_
#include<strstream>_x000D_
using namespace std;_x000D_
_x000D_
int main()_x000D_
{_x000D_
 char ch[]={'a','b','g','e','d','\0'};_x000D_
 strstream s;_x000D_
 s<<ch;_x000D_
 string str1;_x000D_
 s>>str1;_x000D_
 cout<<str1<<endl;_x000D_
 return 0;_x000D_
}
_x000D_
_x000D_
_x000D_

In this way, you also need to add the '\0' at the end of char array.

Also, strstream.h file will be abandoned and be replaced by stringstream

How to specify legend position in matplotlib in graph coordinates

You can change location of legend using loc argument. https://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.legend

import matplotlib.pyplot as plt

plt.subplot(211)
plt.plot([1,2,3], label="test1")
plt.plot([3,2,1], label="test2")
# Place a legend above this subplot, expanding itself to
# fully use the given bounding box.
plt.legend(bbox_to_anchor=(0., 1.02, 1., .102), loc=3,
           ncol=2, mode="expand", borderaxespad=0.)

plt.subplot(223)
plt.plot([1,2,3], label="test1")
plt.plot([3,2,1], label="test2")
# Place a legend to the right of this smaller subplot.
plt.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.)

plt.show()