Programs & Examples On #Doctrine

The Doctrine Project is a collection of open source libraries and tools for dealing with database abstraction and Object-Relational Mapping written in PHP.

How do I delete an entity from symfony2

Symfony is smart and knows how to make the find() by itself :

public function deleteGuestAction(Guest $guest)
{
    if (!$guest) {
        throw $this->createNotFoundException('No guest found');
    }

    $em = $this->getDoctrine()->getEntityManager();
    $em->remove($guest);
    $em->flush();

    return $this->redirect($this->generateUrl('GuestBundle:Page:viewGuests.html.twig'));
}

To send the id in your controller, use {{ path('your_route', {'id': guest.id}) }}

Doctrine 2: Update query with query builder

With a small change, it worked fine for me

$qb=$this->dm->createQueryBuilder('AppBundle:CSSDInstrument')
               ->update()
               ->field('status')->set($status)
               ->field('id')->equals($instrumentId)
               ->getQuery()
               ->execute();

Doctrine - How to print out the real sql, not just the prepared statement?

I made some research for this topic, because i wanted to debug a generated SQL query and execute it in the sql editor. As seen in all the answers, it is a highly technical topic.

When i assume that the initial question is base on dev-env, one very simple answer is missing at the moment. You can just use the build in Symfony profiler. Just click on the Doctrine Tab, Scroll to the query you want to inspect. Then click on "view runnable query" and you can paste your query directly in your SQL editor

More UI base approach but very quick and without debugging code overhead.

enter image description here

tar: Error is not recoverable: exiting now

If you got "Error is not recoverable: exiting now" You might have specified incorrect path references.

[me@host ~]$ tar -xvf nameOfMyTar.tar -C /someSubDirectory/
tar: /someSubDirectory: Cannot open: No such file or directory
tar: Error is not recoverable: exiting now
[me@host ~]$

Make sure you provide correct relative or absolute directory references e.g.:

[me@host ~]$ tar -xvf ./nameOfMyTar.tar -C ./someSubDirectory/
./foo/
./bar/
[me@host ~]$ 

How to use andWhere and orWhere in Doctrine?

One thing missing here: if you have a varying number of elements that you want to put together to something like

WHERE [...] AND (field LIKE '%abc%' OR field LIKE '%def%')

and dont want to assemble a DQL-String yourself, you can use the orX mentioned above like this:

$patterns = ['abc', 'def'];
$orStatements = $qb->expr()->orX();
foreach ($patterns as $pattern) {
    $orStatements->add(
        $qb->expr()->like('field', $qb->expr()->literal('%' . $pattern . '%'))
    );
}
$qb->andWhere($orStatements);

Get the last insert id with doctrine 2?

Calling flush() can potentially add lots of new entities, so there isnt really the notion of "lastInsertId". However Doctrine will populate the identity fields whenever one is generated, so accessing the id field after calling flush will always contain the ID of a newly "persisted" entity.

How to encode Doctrine entities to JSON in Symfony 2.0 AJAX application?

This is more an update (for Symfony v:2.7+ and JmsSerializer v:0.13.*@dev), so to avoid that Jms tries to load and serialise the whole object graph ( or in case of cyclic relation ..)

Model:

use Doctrine\ORM\Mapping as ORM;
use JMS\Serializer\Annotation\ExclusionPolicy;  
use JMS\Serializer\Annotation\Exclude;  
use JMS\Serializer\Annotation\MaxDepth; /* <=== Required */
/**
 * User
 *
 * @ORM\Table(name="user_table")
///////////////// OTHER Doctrine proprieties //////////////
 */
 public class User
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected   $id;

    /**
     * @ORM\ManyToOne(targetEntity="FooBundle\Entity\Game")
     * @ORM\JoinColumn(nullable=false)
     * @MaxDepth(1)
     */
    protected $game;
   /*
      Other proprieties ....and Getters ans setters
      ......................
      ......................
   */

Inside an Action:

use JMS\Serializer\SerializationContext;
  /* Necessary include to enbale max depth */

  $users = $this
              ->getDoctrine()
              ->getManager()
              ->getRepository("FooBundle:User")
              ->findAll();

  $serializer = $this->container->get('jms_serializer');
  $jsonContent = $serializer
                   ->serialize(
                        $users, 
                        'json', 
                        SerializationContext::create()
                                 ->enableMaxDepthChecks()
                  );

  return new Response($jsonContent);

Doctrine2: Best way to handle many-to-many with extra columns in reference table

I was getting from a conflict with join table defined in an association class ( with additional custom fields ) annotation and a join table defined in a many-to-many annotation.

The mapping definitions in two entities with a direct many-to-many relationship appeared to result in the automatic creation of the join table using the 'joinTable' annotation. However the join table was already defined by an annotation in its underlying entity class and I wanted it to use this association entity class's own field definitions so as to extend the join table with additional custom fields.

The explanation and solution is that identified by FMaz008 above. In my situation, it was thanks to this post in the forum 'Doctrine Annotation Question'. This post draws attention to the Doctrine documentation regarding ManyToMany Uni-directional relationships. Look at the note regarding the approach of using an 'association entity class' thus replacing the many-to-many annotation mapping directly between two main entity classes with a one-to-many annotation in the main entity classes and two 'many-to-one' annotations in the associative entity class. There is an example provided in this forum post Association models with extra fields:

public class Person {

  /** @OneToMany(targetEntity="AssignedItems", mappedBy="person") */
  private $assignedItems;

}

public class Items {

    /** @OneToMany(targetEntity="AssignedItems", mappedBy="item") */
    private $assignedPeople;
}

public class AssignedItems {

    /** @ManyToOne(targetEntity="Person")
    * @JoinColumn(name="person_id", referencedColumnName="id")
    */
private $person;

    /** @ManyToOne(targetEntity="Item")
    * @JoinColumn(name="item_id", referencedColumnName="id")
    */
private $item;

}

Order by multiple columns with Doctrine

you can use ->addOrderBy($sort, $order)

Add:Doctrine Querybuilder btw. often uses "special" modifications of the normal methods, see select-addSelect, where-andWhere-orWhere, groupBy-addgroupBy...

Execute raw SQL using Doctrine 2

I had the same problem. You want to look the connection object supplied by the entity manager:

$conn = $em->getConnection();

You can then query/execute directly against it:

$statement = $conn->query('select foo from bar');
$num_rows_effected = $conn->exec('update bar set foo=1');

See the docs for the connection object at http://www.doctrine-project.org/api/dbal/2.0/doctrine/dbal/connection.html

How do I check for a network connection?

The marked answer is 100% fine, however, there are certain cases when the standard method is fooled by virtual cards (virtual box, ...). It's also often desirable to discard some network interfaces based on their speed (serial ports, modems, ...).

Here is a piece of code that checks for these cases:

    /// <summary>
    /// Indicates whether any network connection is available
    /// Filter connections below a specified speed, as well as virtual network cards.
    /// </summary>
    /// <returns>
    ///     <c>true</c> if a network connection is available; otherwise, <c>false</c>.
    /// </returns>
    public static bool IsNetworkAvailable()
    {
        return IsNetworkAvailable(0);
    }

    /// <summary>
    /// Indicates whether any network connection is available.
    /// Filter connections below a specified speed, as well as virtual network cards.
    /// </summary>
    /// <param name="minimumSpeed">The minimum speed required. Passing 0 will not filter connection using speed.</param>
    /// <returns>
    ///     <c>true</c> if a network connection is available; otherwise, <c>false</c>.
    /// </returns>
    public static bool IsNetworkAvailable(long minimumSpeed)
    {
        if (!NetworkInterface.GetIsNetworkAvailable())
            return false;

        foreach (NetworkInterface ni in NetworkInterface.GetAllNetworkInterfaces())
        {
            // discard because of standard reasons
            if ((ni.OperationalStatus != OperationalStatus.Up) ||
                (ni.NetworkInterfaceType == NetworkInterfaceType.Loopback) ||
                (ni.NetworkInterfaceType == NetworkInterfaceType.Tunnel))
                continue;

            // this allow to filter modems, serial, etc.
            // I use 10000000 as a minimum speed for most cases
            if (ni.Speed < minimumSpeed)
                continue;

            // discard virtual cards (virtual box, virtual pc, etc.)
            if ((ni.Description.IndexOf("virtual", StringComparison.OrdinalIgnoreCase) >= 0) ||
                (ni.Name.IndexOf("virtual", StringComparison.OrdinalIgnoreCase) >= 0))
                continue;

            // discard "Microsoft Loopback Adapter", it will not show as NetworkInterfaceType.Loopback but as Ethernet Card.
            if (ni.Description.Equals("Microsoft Loopback Adapter", StringComparison.OrdinalIgnoreCase))
                continue;

            return true;
        }
        return false;
    }

Chrome Dev Tools - Modify javascript and reload

Yes, just open the "Source" Tab in the dev-tools and navigate to the script you want to change . Make your adjustments directly in the dev tools window and then hit ctrl+s to save the script - know the new js will be used until you refresh the whole page.

Uploading file using POST request in Node.js

You can also use the "custom options" support from the request library. This format allows you to create a multi-part form upload, but with a combined entry for both the file and extra form information, like filename or content-type. I have found that some libraries expect to receive file uploads using this format, specifically libraries like multer.

This approach is officially documented in the forms section of the request docs - https://github.com/request/request#forms

//toUpload is the name of the input file: <input type="file" name="toUpload">

let fileToUpload = req.file;

let formData = {
    toUpload: {
      value: fs.createReadStream(path.join(__dirname, '..', '..','upload', fileToUpload.filename)),
      options: {
        filename: fileToUpload.originalname,
        contentType: fileToUpload.mimeType
      }
    }
  };
let options = {
    url: url,
    method: 'POST',
    formData: formData
  }
request(options, function (err, resp, body) {
    if (err)
      cb(err);

    if (!err && resp.statusCode == 200) {
      cb(null, body);
    }
  });

Download file from an ASP.NET Web API method using AngularJS

We also had to develop a solution which would even work with APIs requiring authentication (see this article)

Using AngularJS in a nutshell here is how we did it:

Step 1: Create a dedicated directive

// jQuery needed, uses Bootstrap classes, adjust the path of templateUrl
app.directive('pdfDownload', function() {
return {
    restrict: 'E',
    templateUrl: '/path/to/pdfDownload.tpl.html',
    scope: true,
    link: function(scope, element, attr) {
        var anchor = element.children()[0];

        // When the download starts, disable the link
        scope.$on('download-start', function() {
            $(anchor).attr('disabled', 'disabled');
        });

        // When the download finishes, attach the data to the link. Enable the link and change its appearance.
        scope.$on('downloaded', function(event, data) {
            $(anchor).attr({
                href: 'data:application/pdf;base64,' + data,
                download: attr.filename
            })
                .removeAttr('disabled')
                .text('Save')
                .removeClass('btn-primary')
                .addClass('btn-success');

            // Also overwrite the download pdf function to do nothing.
            scope.downloadPdf = function() {
            };
        });
    },
    controller: ['$scope', '$attrs', '$http', function($scope, $attrs, $http) {
        $scope.downloadPdf = function() {
            $scope.$emit('download-start');
            $http.get($attrs.url).then(function(response) {
                $scope.$emit('downloaded', response.data);
            });
        };
    }] 
});

Step 2: Create a template

<a href="" class="btn btn-primary" ng-click="downloadPdf()">Download</a>

Step 3: Use it

<pdf-download url="/some/path/to/a.pdf" filename="my-awesome-pdf"></pdf-download>

This will render a blue button. When clicked, a PDF will be downloaded (Caution: the backend has to deliver the PDF in Base64 encoding!) and put into the href. The button turns green and switches the text to Save. The user can click again and will be presented with a standard download file dialog for the file my-awesome.pdf.

Angular2 equivalent of $document.ready()

Copying the answer from Chris:

Got it working:

import {AfterViewInit} from 'angular2/core';    

export class HomeCmp implements AfterViewInit {    

    ngAfterViewInit() {
       //Copy in all the js code from the script.js. Typescript will complain but it works just fine
    }

Inline comments for Bash?

Here's my solution for inline comments in between multiple piped commands.

Example uncommented code:

    #!/bin/sh
    cat input.txt \
    | grep something \
    | sort -r

Solution for a pipe comment (using a helper function):

    #!/bin/sh
    pipe_comment() {
        cat - 
    }
    cat input.txt \
    | pipe_comment "filter down to lines that contain the word: something" \
    | grep something \
    | pipe_comment "reverse sort what is left" \
    | sort -r

Or if you prefer, here's the same solution without the helper function, but it's a little messier:

    #!/bin/sh
    cat input.txt \
    | cat - `: filter down to lines that contain the word: something` \
    | grep something \
    | cat - `: reverse sort what is left` \
    | sort -r

What does ||= (or-equals) mean in Ruby?

It's like lazy instantiation. If the variable is already defined it will take that value instead of creating the value again.

jQuery get the location of an element relative to window

Try this to get the location of an element relative to window.

_x000D_
_x000D_
        $("button").click(function(){_x000D_
            var offset = $("#simplebox").offset();_x000D_
            alert("Current position of the box is: (left: " + offset.left + ", top: " + offset.top + ")");_x000D_
        });
_x000D_
    #simplebox{_x000D_
        width:150px;_x000D_
        height:100px;_x000D_
        background: #FBBC09;_x000D_
        margin: 150px 100px;_x000D_
    }
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<button type="button">Get Box Position</button>_x000D_
    <p><strong>Note:</strong> Play with the value of margin property to see how the jQuery offest() method works.</p>_x000D_
    <div id="simplebox"></div>
_x000D_
_x000D_
_x000D_

See more @ Get the position of an element relative to the document with jQuery

ES6 export default with multiple functions referring to each other

One alternative is to change up your module. Generally if you are exporting an object with a bunch of functions on it, it's easier to export a bunch of named functions, e.g.

export function foo() { console.log('foo') }, 
export function bar() { console.log('bar') },
export function baz() { foo(); bar() }

In this case you are export all of the functions with names, so you could do

import * as fns from './foo';

to get an object with properties for each function instead of the import you'd use for your first example:

import fns from './foo';

How to attach source or JavaDoc in eclipse for any jar file e.g. JavaFX?

To attach the Java source code with Eclipse,

When you install the JDK, you must have selected the option to install the Java source files too. This will copy the src.zip file in the installation directory. In Eclipse, go to Window -> Preferences -> Java -> Installed JREs -> Add and choose the JDK you have in your system. Eclipse will now list the JARs found in the dialog box. There, select the rt.jar and choose Source Attachment. By default, this will be pointing to the correct src.zip. If not, choose the src.zip file which you have in your java installation directory. java source attach in eclipse Similarly, if you have the javadoc downloaded in your machine, you can configure that too in this dialog box.

Can two or more people edit an Excel document at the same time?

No, sadly:

The Excel 2010 client application does not support co-authoring workbooks in SharePoint Server 2010. However, the Excel client application does support non-real-time co-authoring workbooks stored locally or on network (UNC) paths by using the Shared Workbook feature. Co-authoring workbooks in SharePoint is supported by using the Microsoft Excel Web App, included with Office Web Apps

From Co-authoring overview (SharePoint Server 2010)

...and not for SharePoint 2013 either. Though it works for pretty much all other Office documents. Go figure.

gnuplot plotting multiple line graphs

I think your problem is your version numbers. Try making 8.1 --> 8.01, and so forth. That should put the points in the right order.

Alternatively, you could plot using X, where X is the column number you want, instead of using 1:X. That will plot those values on the y axis and integers on the x axis. Try:

plot "ls.dat" using 2 title 'Removed' with lines, \
     "ls.dat" using 3 title 'Added' with lines, \
     "ls.dat" using 4 title 'Modified' with lines

How to find largest objects in a SQL Server database?

@marc_s's answer is very great and I've been using it for few years. However, I noticed that the script misses data in some columnstore indexes and doesn't show complete picture. E.g. when you do SUM(TotalSpace) against the script and compare it with total space database property in Management Studio the numbers don't match in my case (Management Studio shows larger numbers). I modified the script to overcome this issue and extended it a little bit:

select
    tables.[name] as table_name,
    schemas.[name] as schema_name,
    isnull(db_name(dm_db_index_usage_stats.database_id), 'Unknown') as database_name,
    sum(allocation_units.total_pages) * 8 as total_space_kb,
    cast(round(((sum(allocation_units.total_pages) * 8) / 1024.00), 2) as numeric(36, 2)) as total_space_mb,
    sum(allocation_units.used_pages) * 8 as used_space_kb,
    cast(round(((sum(allocation_units.used_pages) * 8) / 1024.00), 2) as numeric(36, 2)) as used_space_mb,
    (sum(allocation_units.total_pages) - sum(allocation_units.used_pages)) * 8 as unused_space_kb,
    cast(round(((sum(allocation_units.total_pages) - sum(allocation_units.used_pages)) * 8) / 1024.00, 2) as numeric(36, 2)) as unused_space_mb,
    count(distinct indexes.index_id) as indexes_count,
    max(dm_db_partition_stats.row_count) as row_count,
    iif(max(isnull(user_seeks, 0)) = 0 and max(isnull(user_scans, 0)) = 0 and max(isnull(user_lookups, 0)) = 0, 1, 0) as no_reads,
    iif(max(isnull(user_updates, 0)) = 0, 1, 0) as no_writes,
    max(isnull(user_seeks, 0)) as user_seeks,
    max(isnull(user_scans, 0)) as user_scans,
    max(isnull(user_lookups, 0)) as user_lookups,
    max(isnull(user_updates, 0)) as user_updates,
    max(last_user_seek) as last_user_seek,
    max(last_user_scan) as last_user_scan,
    max(last_user_lookup) as last_user_lookup,
    max(last_user_update) as last_user_update,
    max(tables.create_date) as create_date,
    max(tables.modify_date) as modify_date
from 
    sys.tables
    left join sys.schemas on schemas.schema_id = tables.schema_id
    left join sys.indexes on tables.object_id = indexes.object_id
    left join sys.partitions on indexes.object_id = partitions.object_id and indexes.index_id = partitions.index_id
    left join sys.allocation_units on partitions.partition_id = allocation_units.container_id
    left join sys.dm_db_index_usage_stats on tables.object_id = dm_db_index_usage_stats.object_id and indexes.index_id = dm_db_index_usage_stats.index_id
    left join sys.dm_db_partition_stats on tables.object_id = dm_db_partition_stats.object_id and indexes.index_id = dm_db_partition_stats.index_id
group by schemas.[name], tables.[name], isnull(db_name(dm_db_index_usage_stats.database_id), 'Unknown')
order by 5 desc

Hope it will be helpful for someone. This script was tested against large TB-wide databases with hundreds of different tables, indexes and schemas.

What is the difference between VFAT and FAT32 file systems?

FAT32 along with FAT16 and FAT12 are File System Types, but vfat along with umsdos and msdos are drivers, used to mount the FAT file systems in Linux. The choosing of the driver determines how some of the features are applied to the file system, for example, systems mounted with msdos driver don't have long filenames (they are 8.3 format). vfat is the most common driver for mounting FAT32 file systems nowadays.

Source: this wikipedia article

Output of commands like df and lsblk indeed show vfat as the File System Type. But sudo file -sL /dev/<partition> shows FAT (32 bit) if a File System is FAT32.

You can confirm vfat is a module and not a File System Type by running modinfo vfat.

Generating (pseudo)random alpha-numeric strings

Jeremy's answer is great. If, like me, you're unsure of how to implement range(), you can see my version using range().

<?php
$character_array = array_merge(range('a', 'z'), range(0, 9));
$string = "";
    for($i = 0; $i < 6; $i++) {
        $string .= $character_array[rand(0, (count($character_array) - 1))];
    }
echo $string;
?>

This does the exact same thing as Jeremy's but uses merged arrays where he uses a string, and uses count() where he uses strlen().

Remove first 4 characters of a string with PHP

You could use the substr function please check following example,

$string1 = "tarunmodi";
$first4 = substr($string1, 4);
echo $first4;

Output: nmodi

SQL SERVER, SELECT statement with auto generate row id

This will work in SQL Server 2008.

select  top 100 ROW_NUMBER() OVER (ORDER BY tmp.FirstName) ,* from tmp

Cheers

What exactly is OAuth (Open Authorization)?

Simply put OAuth is a way for applications to gain credentials to your information without directly getting your user login information to some website. For example if you write an application on your own website and want it to use data from a user's facebook account, you can use OAuth to get a token via a callback url and then use that token to make calls to the facebook API to get their use data until the token expires. Websites rely on it because it allows programmers to access their data without the user having to directly disclose their information and spread their credentials around online but still provide a level of protection to the data. Will it become the de facto method of authorization? Perhaps, it's been gaining a lot of support recently from Twitter, Facebook, and the likes where other programmers want to build applications around user data.

How do I import material design library to Android Studio?

If you migrated to AndroidX you should add the dependency in graddle like this:

com.google.android.material:material:1.0.0-rc01

What does "<>" mean in Oracle

It means not equal to

Should I use != or <> for not equal in TSQL?

Have a look at the link. It has detailed explanation of what to use for what.

fstream won't create a file

This will do:

#include <fstream>
#include <iostream>
using std::fstream;

int main(int argc, char *argv[]) {
    fstream file;
    file.open("test.txt",std::ios::out);
    file << fflush;
    file.close();
}

Correct format specifier for double in printf

Given the C99 standard (namely, the N1256 draft), the rules depend on the function kind: fprintf (printf, sprintf, ...) or scanf.

Here are relevant parts extracted:

Foreword

This second edition cancels and replaces the first edition, ISO/IEC 9899:1990, as amended and corrected by ISO/IEC 9899/COR1:1994, ISO/IEC 9899/AMD1:1995, and ISO/IEC 9899/COR2:1996. Major changes from the previous edition include:

  • %lf conversion specifier allowed in printf

7.19.6.1 The fprintf function

7 The length modifiers and their meanings are:

l (ell) Specifies that (...) has no effect on a following a, A, e, E, f, F, g, or G conversion specifier.

L Specifies that a following a, A, e, E, f, F, g, or G conversion specifier applies to a long double argument.

The same rules specified for fprintf apply for printf, sprintf and similar functions.

7.19.6.2 The fscanf function

11 The length modifiers and their meanings are:

l (ell) Specifies that (...) that a following a, A, e, E, f, F, g, or G conversion specifier applies to an argument with type pointer to double;

L Specifies that a following a, A, e, E, f, F, g, or G conversion specifier applies to an argument with type pointer to long double.

12 The conversion specifiers and their meanings are: a,e,f,g Matches an optionally signed floating-point number, (...)

14 The conversion specifiers A, E, F, G, and X are also valid and behave the same as, respectively, a, e, f, g, and x.

The long story short, for fprintf the following specifiers and corresponding types are specified:

  • %f -> double
  • %Lf -> long double.

and for fscanf it is:

  • %f -> float
  • %lf -> double
  • %Lf -> long double.

Remove or adapt border of frame of legend using matplotlib

When plotting a plot using matplotlib:

How to remove the box of the legend?

plt.legend(frameon=False)

How to change the color of the border of the legend box?

leg = plt.legend()
leg.get_frame().set_edgecolor('b')

How to remove only the border of the box of the legend?

leg = plt.legend()
leg.get_frame().set_linewidth(0.0)

Remove Rows From Data Frame where a Row matches a String

if you wish to using dplyr, for to remove row "Foo":

df %>%
 filter(!C=="Foo")

Prevent scrolling of parent element when inner element scroll position reaches top/bottom?

I was searching for this for MooTools and this was the first that came up. The original MooTools example would work with scrolling up, but not scrolling down so I decided to write this one.


var stopScroll = function (e) {
    var scrollTo = null;
    if (e.event.type === 'mousewheel') {
        scrollTo = (e.event.wheelDelta * -1);
    } else if (e.event.type === 'DOMMouseScroll') {
        scrollTo = 40 * e.event.detail;
    }
    if (scrollTo) {
        e.preventDefault();
        this.scrollTo(0, scrollTo + this.scrollTop);
    }
    return false;
};

Usage:

(function)($){
    window.addEvent('domready', function(){
        $$('.scrollable').addEvents({
             'mousewheel': stopScroll,
             'DOMMouseScroll': stopScroll
        });
    });
})(document.id);

Generate Row Serial Numbers in SQL Query

Using Common Table Expression (CTE)

WITH CTE AS(
    SELECT ROW_NUMBER() OVER(ORDER BY CustomerId) AS RowNumber,
    Customers.*
    FROM Customers
)
SELECT * FROM CTE

Check if a number is a perfect square

This response doesn't pertain to your stated question, but to an implicit question I see in the code you posted, ie, "how to check if something is an integer?"

The first answer you'll generally get to that question is "Don't!" And it's true that in Python, typechecking is usually not the right thing to do.

For those rare exceptions, though, instead of looking for a decimal point in the string representation of the number, the thing to do is use the isinstance function:

>>> isinstance(5,int)
True
>>> isinstance(5.0,int)
False

Of course this applies to the variable rather than a value. If I wanted to determine whether the value was an integer, I'd do this:

>>> x=5.0
>>> round(x) == x
True

But as everyone else has covered in detail, there are floating-point issues to be considered in most non-toy examples of this kind of thing.

How can one print a size_t variable portably using the printf family?

Extending on Adam Rosenfield's answer for Windows.

I tested this code with on both VS2013 Update 4 and VS2015 preview:

// test.c

#include <stdio.h>
#include <BaseTsd.h> // see the note below

int main()
{
    size_t x = 1;
    SSIZE_T y = 2;
    printf("%zu\n", x);  // prints as unsigned decimal
    printf("%zx\n", x);  // prints as hex
    printf("%zd\n", y);  // prints as signed decimal
    return 0;
}

VS2015 generated binary outputs:

1
1
2

while the one generated by VS2013 says:

zu
zx
zd

Note: ssize_t is a POSIX extension and SSIZE_T is similar thing in Windows Data Types, hence I added <BaseTsd.h> reference.

Additionally, except for the follow C99/C11 headers, all C99 headers are available in VS2015 preview:

C11 - <stdalign.h>
C11 - <stdatomic.h>
C11 - <stdnoreturn.h>
C99 - <tgmath.h>
C11 - <threads.h>

Also, C11's <uchar.h> is now included in latest preview.

For more details, see this old and the new list for standard conformance.

The remote server returned an error: (403) Forbidden

Setting:

request.Referer = @"http://www.somesite.com/";

and adding cookies than worked for me

How to fix 'Notice: Undefined index:' in PHP form action

use isset for this purpose

<?php

 $index = 1;
 if(isset($_POST['filename'])) {
     $filename = $_POST['filename'];
     echo $filename;
 }

?>

Use CSS to automatically add 'required field' asterisk to form inputs

.required label {
    font-weight: bold;
}
.required label:after {
    color: #e32;
    content: ' *';
    display:inline;
}

Fiddle with your exact structure: http://jsfiddle.net/bQ859/

How to "git show" a merge commit with combined diff output even when every changed file agrees with one of the parents?

You can create branch with HEAD set to one commit before merge. Then, you can do:

git merge --squash testing

This will merge, but not commit. Then:

git diff

How to set placeholder value using CSS?

AFAIK, you can't do it with CSS alone. CSS has content rule but even that can be used to insert content before or after an element using pseudo selectors. You need to resort to javascript for that OR use placeholder attribute if you are using HTML5 as pointed out by @Blender.

ggplot geom_text font size control

Here are a few options for changing text / label sizes

library(ggplot2)

# Example data using mtcars

a <- aggregate(mpg ~ vs + am , mtcars, function(i) round(mean(i)))

p <- ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + 
            geom_bar(stat="identity",position="dodge") + 
            geom_text(data = a, aes(label = mpg), 
                            position = position_dodge(width=0.9),  size=20)

The size in the geom_text changes the size of the geom_text labels.

p <- p + theme(axis.text = element_text(size = 15)) # changes axis labels

p <- p + theme(axis.title = element_text(size = 25)) # change axis titles

p <- p + theme(text = element_text(size = 10)) # this will change all text size 
                                                             # (except geom_text)


For this And why size of 10 in geom_text() is different from that in theme(text=element_text()) ?

Yes, they are different. I did a quick manual check and they appear to be in the ratio of ~ (14/5) for geom_text sizes to theme sizes.

So a horrible fix for uniform sizes is to scale by this ratio

geom.text.size = 7
theme.size = (14/5) * geom.text.size

ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + 
  geom_bar(stat="identity",position="dodge") + 
  geom_text(data = a, aes(label = mpg), 
            position = position_dodge(width=0.9),  size=geom.text.size) + 
  theme(axis.text = element_text(size = theme.size, colour="black")) 

This of course doesn't explain why? and is a pita (and i assume there is a more sensible way to do this)

How do I get the AM/PM value from a DateTime?

string.Format("{0:hh:mm:ss tt}", DateTime.Now)

This should give you the string value of the time. tt should append the am/pm.

You can also look at the related topic:

How do you get the current time of day?

Can I add background color only for padding?

I am sorry everyone that this is the solution the true one where you dont have to actually set the padding.

http://jsfiddle.net/techsin/TyXRY/1/

What i have done...

  • Applied two gradients on background with both having one start and end color. Instead of using solid color. Reason being that you can't have two solid colors for one background.
  • Then applied different background-clip property to each.
  • thus making one color extend to content box and other to border, revealing the padding.

Clever if i say so to myself.

div {
    padding: 35px;
    background-image:
      linear-gradient(to bottom,
        rgba(240, 255, 40, 1) 0%,
        rgba(240, 255, 40, 1) 100%),
      linear-gradient(to bottom,
        rgba(240, 40, 40, 1) 0%,
        rgba(240, 40, 40, 1) 100%);
    background-clip: content-box, padding-box;
}

Using GregorianCalendar with SimpleDateFormat

SimpleDateFormat.format() method takes a Date as a parameter. You can get a Date from a Calendar by calling its getTime() method:

public static String format(GregorianCalendar calendar) {
    SimpleDateFormat fmt = new SimpleDateFormat("dd-MMM-yyyy");
    fmt.setCalendar(calendar);
    String dateFormatted = fmt.format(calendar.getTime());

    return dateFormatted;
}

Also note that the months start at 0, so you probably meant:

int month = Integer.parseInt(splitDate[1]) - 1;

Remove legend ggplot 2.2

There might be another solution to this:
Your code was:

geom_point(aes(..., show.legend = FALSE))

You can specify the show.legend parameter after the aes call:

geom_point(aes(...), show.legend = FALSE)

then the corresponding legend should disappear

Bash: Echoing a echo command with a variable in bash

The immediate problem is you have is with quoting: by using double quotes ("..."), your variable references are instantly expanded, which is probably not what you want.

Use single quotes instead - strings inside single quotes are not expanded or interpreted in any way by the shell.

(If you want selective expansion inside a string - i.e., expand some variable references, but not others - do use double quotes, but prefix the $ of references you do not want expanded with \; e.g., \$var).

However, you're better off using a single here-doc[ument], which allows you to create multi-line stdin input on the spot, bracketed by two instances of a self-chosen delimiter, the opening one prefixed by <<, and the closing one on a line by itself - starting at the very first column; search for Here Documents in man bash or at http://www.gnu.org/software/bash/manual/html_node/Redirections.html.

If you quote the here-doc delimiter (EOF in the code below), variable references are also not expanded. As @chepner points out, you're free to choose the method of quoting in this case: enclose the delimiter in single quotes or double quotes, or even simply arbitrarily escape one character in the delimiter with \:

echo "creating new script file."

cat <<'EOF'  > "$servfile"
#!/bin/bash
read -p "Please enter a service: " ser
servicetest=`getsebool -a | grep ${ser}` 
if [ $servicetest > /dev/null ]; then 
  echo "we are now going to work with ${ser}"
else
  exit 1
fi
EOF

As @BruceK notes, you can prefix your here-doc delimiter with - (applied to this example: <<-"EOF") in order to have leading tabs stripped, allowing for indentation that makes the actual content of the here-doc easier to discern. Note, however, that this only works with actual tab characters, not leading spaces.

Employing this technique combined with the afterthoughts regarding the script's content below, we get (again, note that actual tab chars. must be used to lead each here-doc content line for them to get stripped):

cat <<-'EOF' > "$servfile"
    #!/bin/bash
    read -p "Please enter a service name: " ser
    if [[ -n $(getsebool -a | grep "${ser}") ]]; then 
      echo "We are now going to work with ${ser}."
    else
      exit 1
    fi
EOF

Finally, note that in bash even normal single- or double-quoted strings can span multiple lines, but you won't get the benefits of tab-stripping or line-block scoping, as everything inside the quotes becomes part of the string.

Thus, note how in the following #!/bin/bash has to follow the opening ' immediately in order to become the first line of output:

echo '#!/bin/bash
read -p "Please enter a service: " ser
servicetest=$(getsebool -a | grep "${ser}")
if [[ -n $servicetest ]]; then 
  echo "we are now going to work with ${ser}"
else
  exit 1
fi' > "$servfile"

Afterthoughts regarding the contents of your script:

  • The syntax $(...) is preferred over `...` for command substitution nowadays.
  • You should double-quote ${ser} in the grep command, as the command will likely break if the value contains embedded spaces (alternatively, make sure that the valued read contains no spaces or other shell metacharacters).
  • Use [[ -n $servicetest ]] to test whether $servicetest is empty (or perform the command substitution directly inside the conditional) - [[ ... ]] - the preferred form in bash - protects you from breaking the conditional if the $servicetest happens to have embedded spaces; there's NEVER a need to suppress stdout output inside a conditional (whether [ ... ] or [[ ... ]], as no stdout output is passed through; thus, the > /dev/null is redundant (that said, with a command substitution inside a conditional, stderr output IS passed through).

VBA setting the formula for a cell

Try:

.Formula = "='" & strProjectName & "'!" & Cells(2, 7).Address

If your worksheet name (strProjectName) has spaces, you need to include the single quotes in the formula string.

If this does not resolve it, please provide more information about the specific error or failure.

Update

In comments you indicate you're replacing spaces with underscores. Perhaps you are doing something like:

strProjectName = Replace(strProjectName," ", "_")

But if you're not also pushing that change to the Worksheet.Name property, you can expect these to happen:

  1. The file browse dialog appears
  2. The formula returns #REF error

The reason for both is that you are passing a reference to a worksheet that doesn't exist, which is why you get the #REF error. The file dialog is an attempt to let you correct that reference, by pointing to a file wherein that sheet name does exist. When you cancel out, the #REF error is expected.

So you need to do:

Worksheets(strProjectName).Name = Replace(strProjectName," ", "_")
strProjectName = Replace(strProjectName," ", "_")

Then, your formula should work.

add new element in laravel collection object

If you want to add a product into the array you can use:

$item['product'] = $product;

m2eclipse not finding maven dependencies, artifacts not found

I had problems with using m2eclipse (i.e. it did not appear to be installed at all) but I develop a project using IAM - maven plugin for eclipse supported by Eclipse Foundation (or hosted or something like that).

I had sometimes problems as sometimes some strange error appeared for project (it couldn't move something) but simple command (run from eclipse as task or from console) + refresh (F5) solved all problems:

mvn clean

However please note that I created project in eclipse. However I modified pom.xml by hand.

Swift - How to hide back button in navigation item?

In case you're using a UITabBarController:

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    self.tabBarController?.navigationItem.hidesBackButton = true
}

ThreeJS: Remove object from scene

I had The same problem like you have. I try this code and it works just fine: When you create your object put this object.is_ob = true

function loadOBJFile(objFile){            
    /* material of OBJ model */                                          
    var OBJMaterial = new THREE.MeshPhongMaterial({color: 0x8888ff});
    var loader = new THREE.OBJLoader();
    loader.load(objFile, function (object){
        object.traverse (function (child){
            if (child instanceof THREE.Mesh) {
                child.material = OBJMaterial;
            }
        });
        object.position.y = 0.1;
      // add this code
        object.is_ob = true;

        scene.add(object);
    });     
}

function addEntity(object) {
    loadOBJFile(object.name);
}

And then then you delete your object try this code:

function removeEntity(object){
    var obj, i;
            for ( i = scene.children.length - 1; i >= 0 ; i -- ) {
                obj = scene.children[ i ];
                if ( obj.is_ob) {
                    scene.remove(obj);

                }
            }
}

Try that and tell me if that works, it seems that three js doesn't recognize the object after added to the scene. But with this trick it works.

Redirect website after certain amount of time

You're probably looking for the meta refresh tag:

<html>
    <head>
        <meta http-equiv="refresh" content="3;url=http://www.somewhere.com/" />
    </head>
    <body>
        <h1>Redirecting in 3 seconds...</h1>
    </body>
</html>

Note that use of meta refresh is deprecated and frowned upon these days, but sometimes it's the only viable option (for example, if you're unable to do server-side generation of HTTP redirect headers and/or you need to support non-JavaScript clients etc).

Matching a Forward Slash with a regex

You need to escape the / with a \.

/\//ig // matches /

Granting DBA privileges to user in Oracle

You need only to write:

GRANT DBA TO NewDBA;

Because this already makes the user a DB Administrator

The cause of "bad magic number" error when loading a workspace and how to avoid it?

Also worth noting the following from a document by the R Core Team summarizing changes in versions of R after v3.5.0 (here):

R has new serialization format (version 3) which supports custom serialization of ALTREP framework objects... Serialized data in format 3 cannot be read by versions of R prior to version 3.5.0.

I encountered this issue when I saved a workspace in v3.6.0, and then shared the file with a colleague that was using v3.4.2. I was able to resolve the issue by adding "version=2" to my save function.

How to drop a list of rows from Pandas dataframe?

Use DataFrame.drop and pass it a Series of index labels:

In [65]: df
Out[65]: 
       one  two
one      1    4
two      2    3
three    3    2
four     4    1


In [66]: df.drop(df.index[[1,3]])
Out[66]: 
       one  two
one      1    4
three    3    2

What is the return value of os.system() in Python?

"On Unix, the return value is the exit status of the process encoded in the format specified for wait(). Note that POSIX does not specify the meaning of the return value of the C system() function, so the return value of the Python function is system-dependent."

http://docs.python.org/library/os.html#os.system

There is no error, so the exit code is zero

How to close a Java Swing application from the code

Your JFrame default close action can be set to "DISPOSE_ON_CLOSE" instead of EXIT_ON_CLOSE (why people keep using EXIT_ON_CLOSE is beyond me).

If you have any undisposed windows or non-daemon threads, your application will not terminate. This should be considered a error (and solving it with System.exit is a very bad idea).

The most common culprits are java.util.Timer and a custom Thread you've created. Both should be set to daemon or must be explicitly killed.

If you want to check for all active frames, you can use Frame.getFrames(). If all Windows/Frames are disposed of, then use a debugger to check for any non-daemon threads that are still running.

Create Table from JSON Data with angularjs and ng-repeat

Angular 2 or 4:

There's no more ng-repeat, it's *ngFor now in recent Angular versions!

<table style="padding: 20px; width: 60%;">
    <tr>
      <th  align="left">id</th>
      <th  align="left">status</th>
      <th  align="left">name</th>
    </tr>
    <tr *ngFor="let item of myJSONArray">
      <td>{{item.id}}</td>
      <td>{{item.status}}</td>
      <td>{{item.name}}</td>
    </tr>
</table>

Used this simple JSON:

[{"id":1,"status":"active","name":"A"},
{"id":2,"status":"live","name":"B"},
{"id":3,"status":"active","name":"C"},
{"id":6,"status":"deleted","name":"D"},
{"id":4,"status":"live","name":"E"},
{"id":5,"status":"active","name":"F"}]

How do I find out if first character of a string is a number?

To verify only first letter is number or character -- For number Character.isDigit(str.charAt(0)) --return true

For character Character.isLetter(str.charAt(0)) --return true

Python match a string with regex

As everyone else has mentioned it is better to use the "in" operator, it can also act on lists:

line = "This,is,a,sample,string"
lst = ['This', 'sample']
for i in lst:
     i in line

>> True
>> True

When to use DataContract and DataMember attributes?

A data contract is a formal agreement between a service and a client that abstractly describes the data to be exchanged.

Data contract can be explicit or implicit. Simple type such as int, string etc has an implicit data contract. User defined object are explicit or Complex type, for which you have to define a Data contract using [DataContract] and [DataMember] attribute.

A data contract can be defined as follows:

  • It describes the external format of data passed to and from service operations

  • It defines the structure and types of data exchanged in service messages

  • It maps a CLR type to an XML Schema
  • It defines how data types are serialized and deserialized. Through serialization, you convert an object into a sequence of bytes that can be transmitted over a network. Through deserialization, you reassemble an object from a sequence of bytes that you receive from a calling application.
  • It is a versioning system that allows you to manage changes to structured data

We need to include System.Runtime.Serialization reference to the project. This assembly holds the DataContract and DataMember attribute.

Mocking static methods with Mockito

The typical strategy for dodging static methods that you have no way of avoiding using, is by creating wrapped objects and using the wrapper objects instead.

The wrapper objects become facades to the real static classes, and you do not test those.

A wrapper object could be something like

public class Slf4jMdcWrapper {
    public static final Slf4jMdcWrapper SINGLETON = new Slf4jMdcWrapper();

    public String myApisToTheSaticMethodsInSlf4jMdcStaticUtilityClass() {
        return MDC.getWhateverIWant();
    }
}

Finally, your class under test can use this singleton object by, for example, having a default constructor for real life use:

public class SomeClassUnderTest {
    final Slf4jMdcWrapper myMockableObject;

    /** constructor used by CDI or whatever real life use case */
    public myClassUnderTestContructor() {
        this.myMockableObject = Slf4jMdcWrapper.SINGLETON;
    }

    /** constructor used in tests*/
    myClassUnderTestContructor(Slf4jMdcWrapper myMock) {
        this.myMockableObject = myMock;
    }
}

And here you have a class that can easily be tested, because you do not directly use a class with static methods.

If you are using CDI and can make use of the @Inject annotation then it is even easier. Just make your Wrapper bean @ApplicationScoped, get that thing injected as a collaborator (you do not even need messy constructors for testing), and go on with the mocking.

Visually managing MongoDB documents and collections

The real answer is ... No.

So far as I have found there is no reasonable or publicly available Windows MonogoDB client which is really very sad since MongoDB is pretty sweet.

I've thought about throwing together a simple app with WPF on Codeplex ... but I haven't been super motivated.

What would features would you be interested in having? Maybe you can inspire me or others?

For example, do you just want to view DBs / collections & perhaps simple edits (so you don't have to use the shell) or do you require something more complex?

Hook up Raspberry Pi via Ethernet to laptop without router?

I've just implemented and test this successfully. Same situation with my project, want to connect to a Raspberry Pi with no router or wifi. Just a simple ethernet cable.

Using ssh putty program put the address as

raspberrypi.local

Log and in and you can access the terminal.

Alternatively if VNC server is setup, use VNC server and put

raspberrypi.local:1

In the server address. input your VNC server password and you've now got GUI access to do what you want.

In may case it was run scripts in a remote location. In the posters situation, safely shutdown the Pi. Simples Pimples.

Date Format in Swift

Swift 3 and higher

let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .medium
dateFormatter.timeStyle = .none
dateFormatter.locale = Locale.current
print(dateFormatter.string(from: date)) // Jan 2, 2001

This is also helpful when you want to localize your App. The Locale(identifier: ) uses the ISO 639-1 Code. See also the Apple Documentation

Encode a FileStream to base64 with c#

A simple Stream extension method would do the job:

public static class StreamExtensions
{
    public static string ConvertToBase64(this Stream stream)
    {
        var bytes = new Byte[(int)stream.Length];

        stream.Seek(0, SeekOrigin.Begin);
        stream.Read(bytes, 0, (int)stream.Length);

        return Convert.ToBase64String(bytes);
    }
}

The methods for Read (and also Write) and optimized for the respective class (whether is file stream, memory stream, etc.) and will do the work for you. For simple task like this, there is no need of readers, and etc.

The only drawback is that the stream is copied into byte array, but that is how the conversion to base64 via Convert.ToBase64String works unfortunately.

jQuery $.ajax request of dataType json will not retrieve data from PHP script

Well, it might help someone. I was stupid enough to put var_dump('testing'); in the function I was requesting JSON from to be sure the request was actually received. This obviously also echo's as part for the expected json response, and with dataType set to json defined, the request fails.

Wrap long lines in Python

I'm surprised no one mentioned the implicit style above. My preference is to use parens to wrap the string while lining the string lines up visually. Personally I think this looks cleaner and more compact than starting the beginning of the string on a tabbed new line.

Note that these parens are not part of a method call — they're only implicit string literal concatenation.

Python 2:

def fun():
    print ('{0} Here is a really '
           'long sentence with {1}').format(3, 5)

Python 3 (with parens for print function):

def fun():
    print(('{0} Here is a really '
           'long sentence with {1}').format(3, 5))

Personally I think it's cleanest to separate concatenating the long string literal from printing it:

def fun():
    s = ('{0} Here is a really '
         'long sentence with {1}').format(3, 5)
    print(s)

Difference between using gradlew and gradle

gradlew is a wrapper(w - character) that uses gradle.

Under the hood gradlew performs three main things:

  • Download and install the correct gradle version
  • Parse the arguments
  • Call a gradle task

Using Gradle Wrapper we can distribute/share a project to everybody to use the same version and Gradle's functionality(compile, build, install...) even if it has not been installed.

To create a wrapper run:

gradle wrapper

This command generate:

gradle-wrapper.properties will contain the information about the Gradle distribution

*./ Is used on Unix to specify the current directory

In c# is there a method to find the max of 3 numbers?

If, for whatever reason (e.g. Space Engineers API), System.array has no definition for Max nor do you have access to Enumerable, a solution for Max of n values is:

public int Max(int[] values) {
    if(values.Length < 1) {
        return 0;
    }
    if(values.Length < 2) {
        return values[0];
    }
    if(values.Length < 3) {
       return Math.Max(values[0], values[1]); 
    }
    int runningMax = values[0];
    for(int i=1; i<values.Length - 1; i++) {
       runningMax = Math.Max(runningMax, values[i]);
    }
    return runningMax;
}

Not equal <> != operator on NULL

NULL has no value, and so cannot be compared using the scalar value operators.

In other words, no value can ever be equal to (or not equal to) NULL because NULL has no value.

Hence, SQL has special IS NULL and IS NOT NULL predicates for dealing with NULL.

How can I tell gcc not to inline a function?

In case you get a compiler error for __attribute__((noinline)), you can just try:

noinline int func(int arg)
{
    ....
}

What is MVC and what are the advantages of it?

Separation of concerns is the biggy.

Being able to tease these components apart makes the code easier to re-use and independently test. If you don't actually know what MVC is, be careful about trying to understand people's opinions as there is still some contention about what the "Model" is (whether it is the business objects/DataSets/DataTables or if it represents the underlying service layer).

I've seen all sorts of implementations that call themselves MVC but aren't exactly and as the comments in Jeff's article show MVC is a contentious point that I don't think developers will ever fully agree upon.

A good round up of all of the different MVC types is available here.

Android adding simple animations while setvisibility(view.Gone)

I was able to show/hide a menu this way:

MenuView.java (extends FrameLayout)

private final int ANIMATION_DURATION = 500;

public void showMenu()
{
    setVisibility(View.VISIBLE);
    animate()
            .alpha(1f)
            .setDuration(ANIMATION_DURATION)
            .setListener(null);
}

private void hideMenu()
{
    animate()
            .alpha(0f)
            .setDuration(ANIMATION_DURATION)
            .setListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    setVisibility(View.GONE);
                }
            });
}

Source

Using Node.js require vs. ES6 import/export

When it comes to async or maybe lazy loading, then import () is much more powerful. See when we require the component in asynchronous way, then we use import it in some async manner as in const variable using await.

const module = await import('./module.js');

Or if you want to use require() then,

const converter = require('./converter');

Thing is import() is actually async in nature. As mentioned by neehar venugopal in ReactConf, you can use it to dynamically load react components for client side architecture.

Also it is way better when it comes to Routing. That is the one special thing that makes network log to download a necessary part when user connects to specific website to its specific component. e.g. login page before dashboard wouldn't download all components of dashboard. Because what is needed current i.e. login component, that only will be downloaded.

Same goes for export : ES6 export are exactly same as for CommonJS module.exports.

NOTE - If you are developing a node.js project, then you have to strictly use require() as node will throw exception error as invalid token 'import' if you will use import . So node does not support import statements.

UPDATE - As suggested by Dan Dascalescu: Since v8.5.0 (released Sep 2017), node --experimental-modules index.mjs lets you use import without Babel. You can (and should) also publish your npm packages as native ESModule, with backwards compatibility for the old require way.

See this for more clearance where to use async imports - https://www.youtube.com/watch?v=bb6RCrDaxhw

Environment variable in Jenkins Pipeline

You can access the same environment variables from groovy using the same names (e.g. JOB_NAME or env.JOB_NAME).

From the documentation:

Environment variables are accessible from Groovy code as env.VARNAME or simply as VARNAME. You can write to such properties as well (only using the env. prefix):

env.MYTOOL_VERSION = '1.33'
node {
  sh '/usr/local/mytool-$MYTOOL_VERSION/bin/start'
}

These definitions will also be available via the REST API during the build or after its completion, and from upstream Pipeline builds using the build step.

For the rest of the documentation, click the "Pipeline Syntax" link from any Pipeline job enter image description here

HTML Entity Decode

Like Robert K said, don't use jQuery.html().text() to decode html entities as it's unsafe because user input should never have access to the DOM. Read about XSS for why this is unsafe.

Instead try the Underscore.js utility-belt library which comes with escape and unescape methods:

_.escape(string)

Escapes a string for insertion into HTML, replacing &, <, >, ", `, and ' characters.

_.escape('Curly, Larry & Moe');
=> "Curly, Larry &amp; Moe"

_.unescape(string)

The opposite of escape, replaces &amp;, &lt;, &gt;, &quot;, &#96; and &#x27; with their unescaped counterparts.

_.unescape('Curly, Larry &amp; Moe');
=> "Curly, Larry & Moe"

To support decoding more characters, just copy the Underscore unescape method and add more characters to the map.

What's the difference between using CGFloat and float?

As others have said, CGFloat is a float on 32-bit systems and a double on 64-bit systems. However, the decision to do that was inherited from OS X, where it was made based on the performance characteristics of early PowerPC CPUs. In other words, you should not think that float is for 32-bit CPUs and double is for 64-bit CPUs. (I believe, Apple's ARM processors were able to process doubles long before they went 64-bit.) The main performance hit of using doubles is that they use twice the memory and therefore might be slower if you are doing a lot of floating point operations.

Tomcat 7 is not running on browser(http://localhost:8080/ )

Double click on the Tomcat Server under the Servers tab in Eclipse Doing that opens a window in the editor with the top heading being Overview opens (there are 2 tabs-Overview and Modules). In that change the options under Server Locations, and g

What does java.lang.Thread.interrupt() do?

Thread interruption is based on flag interrupt status. For every thread default value of interrupt status is set to false. Whenever interrupt() method is called on thread, interrupt status is set to true.

  1. If interrupt status = true (interrupt() already called on thread), that particular thread cannot go to sleep. If sleep is called on that thread interrupted exception is thrown. After throwing exception again flag is set to false.
  2. If thread is already sleeping and interrupt() is called, thread will come out of sleeping state and throw interrupted Exception.

AngularJS format JSON string output

I guess you want to use to edit the json text. Then you can use ivarni's way:

{{data | json}}
and add an adition attribute to make
 editable

<pre contenteditable="true">{{data | json}}</pre>

Hope this can help you.

Is there a REAL performance difference between INT and VARCHAR primary keys?

It's not about performance. It's about what makes a good primary key. Unique and unchanging over time. You may think an entity such as a country code never changes over time and would be a good candidate for a primary key. But bitter experience is that is seldom so.

INT AUTO_INCREMENT meets the "unique and unchanging over time" condition. Hence the preference.

Java error: Only a type can be imported. XYZ resolves to a package

The tomcat folder structure has Webapps/ROOT/ inside where the WEB-INF folder has to be present. If you place your WEB-INF inside Webapps/ tomcat is not locating the class files and jars.

Checking if a variable is not nil and not zero in ruby

When dealing with a database record, I like to initialize all empty values with 0, using the migration helper:

add_column :products, :price, :integer, default: 0

How can I store HashMap<String, ArrayList<String>> inside a list?

First you need to define the List as :

List<Map<String, ArrayList<String>>> list = new ArrayList<>();

To add the Map to the List , use add(E e) method :

list.add(map);

Svn switch from trunk to branch

In my case, I wanted to check out a new branch that has cut recently but it's it big in size and I want to save time and internet bandwidth, as I'm in a slow metered network

so I copped the previous branch that I already checked in

I went to the working directory, and from svn info, I can see it's on the previous branch I did the following command (you can find this command from svn switch --help)

svn switch ^/branches/newBranchName

go check svn info again you can see it is becoming the newBranchName go ahead and svn up

and this how I got the new branch easily, quickly with minimum data transmitting over the internet

hope sharing my case helps and speeds up your work

Failed to find Build Tools revision 23.0.1

Check your $ANDROID_HOME, sometimes is /usr/local/opt/android, but it's not your install sdk path, change it and fix this problem

Update .NET web service to use TLS 1.2

PowerBI Embedded requires TLS 1.2.

The answer above by Etienne Faucher is your solution. quick link to above answer... quick link to above answer... ( https://stackoverflow.com/a/45442874 )

PowerBI Requires TLS 1.2 June 2020 - This Is your Answer - Consider Forcing your IIS runtime to get up to 4.6 to force the default TLS 1.2 behavior you are looking for from the framework. The above answer gives you a config change only solution.

Symptoms: Forced Closed Rejected TCP/IP Connection to Microsoft PowerBI Embedded that just shows up all of a sudden across your systems.

These PowerBI Calls just stop working with a Hard TCP/IP Close error like a firewall would block a connection. Usually the auth steps work - it is when you hit the service for specific workspace and report id's that it fails.

This is the 2020 note from Microsoft PowerBI about TLS 1.2 required

PowerBIClient

methods that show this problem

GetReportsInGroupAsync GetReportsInGroupAsAdminAsync GetReportsAsync GetReportsAsAdminAsync Microsoft.PowerBI.Api HttpClientHandler Force TLS 1.1 TLS 1.2

Search Error Terms to help people find this: System.Net.Http.HttpRequestException: An error occurred while sending the request System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

How do I download/extract font from chrome developers tools?

I found the Chrome option to be OK but there are quite a few steps to go through to get to the font files. Once you're there, the downloading is super easy. I usually use the dev tools in Safari as there are fewer steps. Just go to the page you want, click on "Show page source" or "show page resources" in the Developer menu (both work for this) and the page resources are listed in folders on the left hand side. Click the font folder and the fonts are listed. Right click and save file. If you are downloading a lot of font files from one site it may be quicker to work your way through Chrome's pathway as the "open in tab" does download the fonts quicker. If you're taking one or two fonts from a lot of different sites, Safari will be quicker overall.

Android View shadow

I know this question has already been answered but I want you to know that I found a drawable on Android Studio that is very similar to the pics you have in the question: Take a look at this:

android:background="@drawable/abc_menu_dropdown_panel_holo_light"

It looks like this:

enter image description here

Hope it will be helpful

Edit

The option above is for the older versions of Android Studio so you may not find it. For newer versions:

android:background="@android:drawable/dialog_holo_light_frame"

Moreover, if you want to have your own custom shape, I suggest to use a drawing software like Photoshop and draw it.

enter image description here

Don't forget to save it as .9.png file (example: my_background.9.png)

Read the documentation: Draw 9-patch

Edit 2

An even better and less hard working solution is to use a CardView and set app:cardPreventCornerOverlap="false" to prevent views to overlap the borders:

<android.support.v7.widget.CardView
    android:id="@+id/card_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:cardCornerRadius="2dp"
    app:cardElevation="2dp"
    app:cardPreventCornerOverlap="false"
    app:contentPadding="0dp">

    <!-- your layout stuff here -->

</android.support.v7.widget.CardView>

Also make sure to have included the latest version in the build.gradle, current is

compile 'com.android.support:cardview-v7:26.0.0'

Yarn install command error No such file or directory: 'install'

I believe all relevant solutions have been provided but here is a subtle situatuion: know that if you don't close and open your terminal again you will not see the effect.

Close your terminal and open then type in your terminal

yarn --version

Cheers!

How to remove youtube branding after embedding video in web page?

You can add ?modestbranding=1 to your url. That will remove the logo.

modestbranding (supported players: AS3, HTML5)

This parameter lets you use a YouTube player that does not show a YouTube logo. Set the parameter value to 1 to prevent the YouTube logo from displaying in the control bar. Note that a small YouTube text label will still display in the upper-right corner of a paused video when the user's mouse pointer hovers over the player.

&showinfo=0 will remove the title bar.

showinfo (supported players: AS3, AS2, HTML5)

Values: 0 or 1. The parameter's default value is 1. If you set the parameter value to 0, then the player will not display information like the video title and uploader before the video starts playing.

You can find all options on the Google Developers website.

Note:

It doesn't fully remove the logo. There is still a small logo on the bottom left.

showinfo is deprecated and will be ignored after September 25, 2018: https://developers.google.com/youtube/player_parameters

jQuery, checkboxes and .is(":checked")

I'm still experiencing this behavior with jQuery 1.7.2. A simple workaround is to defer the execution of the click handler with setTimeout and let the browser do its magic in the meantime:

$("#myCheckbox").click( function() {
    var that = this;
    setTimeout(function(){
        alert($(that).is(":checked"));
    });
});

Can I serve multiple clients using just Flask app.run() as standalone?

flask.Flask.run accepts additional keyword arguments (**options) that it forwards to werkzeug.serving.run_simple - two of those arguments are threaded (a boolean) and processes (which you can set to a number greater than one to have werkzeug spawn more than one process to handle requests).

threaded defaults to True as of Flask 1.0, so for the latest versions of Flask, the default development server will be able to serve multiple clients simultaneously by default. For older versions of Flask, you can explicitly pass threaded=True to enable this behaviour.

For example, you can do

if __name__ == '__main__':
    app.run(threaded=True)

to handle multiple clients using threads in a way compatible with old Flask versions, or

if __name__ == '__main__':
    app.run(threaded=False, processes=3)

to tell Werkzeug to spawn three processes to handle incoming requests, or just

if __name__ == '__main__':
    app.run()

to handle multiple clients using threads if you know that you will be using Flask 1.0 or later.

That being said, Werkzeug's serving.run_simple wraps the standard library's wsgiref package - and that package contains a reference implementation of WSGI, not a production-ready web server. If you are going to use Flask in production (assuming that "production" is not a low-traffic internal application with no more than 10 concurrent users) make sure to stand it up behind a real web server (see the section of Flask's docs entitled Deployment Options for some suggested methods).

How to pass an array to a function in VBA?

This seems unnecessary, but VBA is a strange place. If you declare an array variable, then set it using Array() then pass the variable into your function, VBA will be happy.

Sub test()
    Dim fString As String
    Dim arr() As Variant
    arr = Array("foo", "bar")
    fString = processArr(arr)
End Sub

Also your function processArr() could be written as:

Function processArr(arr() As Variant) As String
    processArr = Replace(Join(arr()), " ", "")
End Function

If you are into the whole brevity thing.

CSS: borders between table columns only

I know this is an old question, but there is a simple, one line solution which works consistently for Chrome, Firefox, etc., as well as IE8 and above (and, for the most part, works on IE7 too - see http://www.quirksmode.org/css/selectors/ for details):

table td + td { border-left:2px solid red; }


The output is something like this:

Col1 | Col2 | Col3

What is making this work is that you are defining a border only on table cells which are adjacent to another table cell. In other words, you're applying the CSS to all cells in a row except the first one.

By applying a left border to the second through the last child, it gives the appearance of the line being "between" the cells.

Python slice first and last element in list

Just thought I'd show how to do this with numpy's fancy indexing:

>>> import numpy
>>> some_list = ['1', 'B', '3', 'D', '5', 'F']
>>> numpy.array(some_list)[[0,-1]]
array(['1', 'F'], 
      dtype='|S1')

Note that it also supports arbitrary index locations, which the [::len(some_list)-1] method would not work for:

>>> numpy.array(some_list)[[0,2,-1]]
array(['1', '3', 'F'], 
      dtype='|S1')

As DSM points out, you can do something similar with itemgetter:

>>> import operator
>>> operator.itemgetter(0, 2, -1)(some_list)
('1', '3', 'F')

SQL server 2008 backup error - Operating system error 5(failed to retrieve text for this error. Reason: 15105)

I've faced this error, when there was no enough free space to create backup.

Can table columns with a Foreign Key be NULL?

I found that when inserting, the null column values had to be specifically declared as NULL, otherwise I would get a constraint violation error (as opposed to an empty string).

multiple packages in context:component-scan, spring config

A delayed response but to give multiple packages using annotation based approach we can use as below:

@ComponentScan({"com.my.package.one","com.my.package.subpackage.two","com.your.package.supersubpackage.two"})

How to pass value from <option><select> to form action

You don't have to use jQuery or Javascript.

Use the name tag of the select and let the form do it's job.

<select name="agent_id" id="agent_id">

Remove duplicates from a dataframe in PySpark

if you have a data frame and want to remove all duplicates -- with reference to duplicates in a specific column (called 'colName'):

count before dedupe:

df.count()

do the de-dupe (convert the column you are de-duping to string type):

from pyspark.sql.functions import col
df = df.withColumn('colName',col('colName').cast('string'))

df.drop_duplicates(subset=['colName']).count()

can use a sorted groupby to check to see that duplicates have been removed:

df.groupBy('colName').count().toPandas().set_index("count").sort_index(ascending=False)

How to get the file path from HTML input form in Firefox 3

Actually, just before FF3 was out, I did some experiments, and FF2 sends only the filename, like did Opera 9.0. Only IE sends the full path. The behavior makes sense, because the server doesn't have to know where the user stores the file on his computer, it is irrelevant to the upload process. Unless you are writing an intranet application and get the file by direct network access!

What have changed (and that's the real point of the bug item you point to) is that FF3 no longer let access to the file path from JavaScript. And won't let type/paste a path there, which is more annoying for me: I have a shell extension which copies the path of a file from Windows Explorer to the clipboard and I used it a lot in such form. I solved the issue by using the DragDropUpload extension. But this becomes off-topic, I fear.

I wonder what your Web forms are doing to stop working with this new behavior.

[EDIT] After reading the page linked by Mike, I see indeed intranet uses of the path (identify a user for example) and local uses (show preview of an image, local management of files). User Jam-es seems to provide a workaround with nsIDOMFile (not tried yet).

Get MAC address using shell script

On a modern GNU/Linux system you can see the available network interfaces listing the content of /sys/class/net/, for example:

$ ls /sys/class/net/
enp0s25  lo  virbr0  virbr0-nic  wlp2s0

You can check if an interface is up looking at operstate in the device directory. For example, here's how you can see if enp0s25 is up:

$ cat /sys/class/net/enp0s25/operstate
up

You can then get the MAC address of that interface with:

$ cat /sys/class/net/enp0s25/address 
ff:00:ff:e9:84:a5

For example, here's a simple bash script that prints MAC addresses for active interfaces:

#!/bin/bash
# getmacifup.sh: Print active NICs MAC addresses
D='/sys/class/net'
for nic in $( ls $D )
do
    echo $nic
    if  grep -q up $D/$nic/operstate
    then
        echo -n '   '
        cat $D/$nic/address
    fi
done

And here's its output on a system with an ethernet and a wifi interface:

$ ./getmacifup.sh
enp0s25
   ff:00:ff:e9:84:a5
lo
wlp2s0

For details see the Kernel documentation


Remember also that from 2015 most GNU/Linux distributions switched to systemd, and don't use ethX interface naming scheme any more - now they use a more robust naming convention based on the hardware topology, see:

How do I install jmeter on a Mac?

Download last version (not 2.5.1 or other old ones) from jmeter.apache.org

Unzip file

Ensure you install a version of JAVA which is compatible, Java 6 or 7 for JMeter 2.11

In bin folder click on jmeter.sh not on jar or execute sh ./apache-jmeter-x.x.x/bin/jmeter in the terminal.

x.x.x is the version you use.

Finally, when started you may want to select System Look and feel for Mac OSX better integration. Menu > Options > Look and Feel > System

TypeError: Can't convert 'int' object to str implicitly

def attributeSelection():
balance = 25
print("Your SP balance is currently 25.")
strength = input("How much SP do you want to put into strength?")
balanceAfterStrength = balance - int(strength)
if balanceAfterStrength == 0:
    print("Your SP balance is now 0.")
    attributeConfirmation()
elif strength < 0:
    print("That is an invalid input. Restarting attribute selection. Keep an eye on your balance this time!")
    attributeSelection()
elif strength > balance:
    print("That is an invalid input. Restarting attribute selection. Keep an eye on your balance this time!")
    attributeSelection()
elif balanceAfterStrength > 0 and balanceAfterStrength < 26:
    print("Ok. You're balance is now at " + str(balanceAfterStrength) + " skill points.")
else:
    print("That is an invalid input. Restarting attribute selection.")
    attributeSelection()

Are 'Arrow Functions' and 'Functions' equivalent / interchangeable?

tl;dr: No! Arrow functions and function declarations / expressions are not equivalent and cannot be replaced blindly.
If the function you want to replace does not use this, arguments and is not called with new, then yes.


As so often: it depends. Arrow functions have different behavior than function declarations / expressions, so let's have a look at the differences first:

1. Lexical this and arguments

Arrow functions don't have their own this or arguments binding. Instead, those identifiers are resolved in the lexical scope like any other variable. That means that inside an arrow function, this and arguments refer to the values of this and arguments in the environment the arrow function is defined in (i.e. "outside" the arrow function):

_x000D_
_x000D_
// Example using a function expression
function createObject() {
  console.log('Inside `createObject`:', this.foo);
  return {
    foo: 42,
    bar: function() {
      console.log('Inside `bar`:', this.foo);
    },
  };
}

createObject.call({foo: 21}).bar(); // override `this` inside createObject
_x000D_
_x000D_
_x000D_

_x000D_
_x000D_
// Example using a arrow function
function createObject() {
  console.log('Inside `createObject`:', this.foo);
  return {
    foo: 42,
    bar: () => console.log('Inside `bar`:', this.foo),
  };
}

createObject.call({foo: 21}).bar(); // override `this` inside createObject
_x000D_
_x000D_
_x000D_

In the function expression case, this refers to the object that was created inside the createObject. In the arrow function case, this refers to this of createObject itself.

This makes arrow functions useful if you need to access the this of the current environment:

// currently common pattern
var that = this;
getData(function(data) {
  that.data = data;
});

// better alternative with arrow functions
getData(data => {
  this.data = data;
});

Note that this also means that is not possible to set an arrow function's this with .bind or .call.

If you are not very familiar with this, consider reading

2. Arrow functions cannot be called with new

ES2015 distinguishes between functions that are callable and functions that are constructable. If a function is constructable, it can be called with new, i.e. new User(). If a function is callable, it can be called without new (i.e. normal function call).

Functions created through function declarations / expressions are both constructable and callable.
Arrow functions (and methods) are only callable. class constructors are only constructable.

If you are trying to call a non-callable function or to construct a non-constructable function, you will get a runtime error.


Knowing this, we can state the following.

Replaceable:

  • Functions that don't use this or arguments.
  • Functions that are used with .bind(this)

Not replaceable:

  • Constructor functions
  • Function / methods added to a prototype (because they usually use this)
  • Variadic functions (if they use arguments (see below))

Lets have a closer look at this using your examples:

Constructor function

This won't work because arrow functions cannot be called with new. Keep using a function declaration / expression or use class.

Prototype methods

Most likely not, because prototype methods usually use this to access the instance. If they don't use this, then you can replace it. However, if you primarily care for concise syntax, use class with its concise method syntax:

class User {
  constructor(name) {
    this.name = name;
  }
  
  getName() {
    return this.name;
  }
}

Object methods

Similarly for methods in an object literal. If the method wants to reference the object itself via this, keep using function expressions, or use the new method syntax:

const obj = {
  getName() {
    // ...
  },
};

Callbacks

It depends. You should definitely replace it if you are aliasing the outer this or are using .bind(this):

// old
setTimeout(function() {
  // ...
}.bind(this), 500);

// new
setTimeout(() => {
  // ...
}, 500);

But: If the code which calls the callback explicitly sets this to a specific value, as is often the case with event handlers, especially with jQuery, and the callback uses this (or arguments), you cannot use an arrow function!

Variadic functions

Since arrow functions don't have their own arguments, you cannot simply replace them with an arrow function. However, ES2015 introduces an alternative to using arguments: the rest parameter.

// old
function sum() {
  let args = [].slice.call(arguments);
  // ...
}

// new
const sum = (...args) => {
  // ...
};

Related question:

Further resources:

What is a singleton in C#?

Here's what singleton is: http://en.wikipedia.org/wiki/Singleton_pattern

I don't know C#, but it's actually the same thing in all languages, only implementation differs.

You should generally avoid singleton when it's possible, but in some situations it's very convenient.

Sorry for my English ;)

Scanner only reads first word instead of line

Replace next() with nextLine():

String productDescription = input.nextLine();

The Import android.support.v7 cannot be resolved

  1. Go to your project in the navigator, right click on properties.

  2. Go to the Java Build Path tab on the left.

  3. Go to the libraries tab on top.

  4. Click add external jars.

  5. Go to your ADT Bundle folder, go to sdk/extras/android/support/v7/appcompat/libs.

  6. Select the file android-support-v7-appcompat.jar

  7. Go to order and export and check the box next to your new jar.

  8. Click ok.

Android Studio: Gradle: error: cannot find symbol variable

You shouldn't be importing android.R. That should be automatically generated and recognized. This question contains a lot of helpful tips if you get some error referring to R after removing the import.

Some basic steps after removing the import, if those errors appear:

  • Clean your build, then rebuild
  • Make sure there are no errors or typos in your XML files
  • Make sure your resource names consist of [a-z0-9.]. Capitals or symbols are not allowed for some reason.
  • Perform a Gradle sync (via Tools > Android > Sync Project with Gradle Files)

MySQL: selecting rows where a column is null

There's also a <=> operator:

SELECT pid FROM planets WHERE userid <=> NULL

Would work. The nice thing is that <=> can also be used with non-NULL values:

SELECT NULL <=> NULL yields 1.

SELECT 42 <=> 42 yields 1 as well.

See here: https://dev.mysql.com/doc/refman/5.7/en/comparison-operators.html#operator_equal-to

Creating a thumbnail from an uploaded image

just in case you need to create thumb with a max width and a max height ...

function makeThumbnails($updir, $img, $id,$MaxWe=100,$MaxHe=150){
    $arr_image_details = getimagesize($img); 
    $width = $arr_image_details[0];
    $height = $arr_image_details[1];

    $percent = 100;
    if($width > $MaxWe) $percent = floor(($MaxWe * 100) / $width);

    if(floor(($height * $percent)/100)>$MaxHe)  
    $percent = (($MaxHe * 100) / $height);

    if($width > $height) {
        $newWidth=$MaxWe;
        $newHeight=round(($height*$percent)/100);
    }else{
        $newWidth=round(($width*$percent)/100);
        $newHeight=$MaxHe;
    }

    if ($arr_image_details[2] == 1) {
        $imgt = "ImageGIF";
        $imgcreatefrom = "ImageCreateFromGIF";
    }
    if ($arr_image_details[2] == 2) {
        $imgt = "ImageJPEG";
        $imgcreatefrom = "ImageCreateFromJPEG";
    }
    if ($arr_image_details[2] == 3) {
        $imgt = "ImagePNG";
        $imgcreatefrom = "ImageCreateFromPNG";
    }


    if ($imgt) {
        $old_image = $imgcreatefrom($img);
        $new_image = imagecreatetruecolor($newWidth, $newHeight);
        imagecopyresized($new_image, $old_image, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);

       $imgt($new_image, $updir."".$id."_t.jpg");
        return;    
    }
}

How do you keep parents of floated elements from collapsing?

Rather than putting overflow:auto on the parent, put overflow:hidden

The first CSS I write for any webpage is always:

div {
  overflow:hidden;
}

Then I never have to worry about it.

LINQ: combining join and group by

Once you've done this

group p by p.SomeId into pg  

you no longer have access to the range variables used in the initial from. That is, you can no longer talk about p or bp, you can only talk about pg.

Now, pg is a group and so contains more than one product. All the products in a given pg group have the same SomeId (since that's what you grouped by), but I don't know if that means they all have the same BaseProductId.

To get a base product name, you have to pick a particular product in the pg group (As you are doing with SomeId and CountryCode), and then join to BaseProducts.

var result = from p in Products                         
 group p by p.SomeId into pg                         
 // join *after* group
 join bp in BaseProducts on pg.FirstOrDefault().BaseProductId equals bp.Id         
 select new ProductPriceMinMax { 
       SomeId = pg.FirstOrDefault().SomeId, 
       CountryCode = pg.FirstOrDefault().CountryCode, 
       MinPrice = pg.Min(m => m.Price), 
       MaxPrice = pg.Max(m => m.Price),
       BaseProductName = bp.Name  // now there is a 'bp' in scope
 };

That said, this looks pretty unusual and I think you should step back and consider what you are actually trying to retrieve.

Java function for arrays like PHP's join()?

If you've landed here looking for a quick array-to-string conversion, try Arrays.toString().

Creates a String representation of the Object[] passed. The result is surrounded by brackets ("[]"), each element is converted to a String via the String.valueOf(Object) and separated by ", ". If the array is null, then "null" is returned.

DB2 Date format

SELECT VARCHAR_FORMAT(CURRENT TIMESTAMP, 'YYYYMMDD')
FROM SYSIBM.SYSDUMMY1

Should work on both Mainframe and Linux/Unix/Windows DB2. Info Center entry for VARCHAR_FORMAT().

How to implement my very own URI scheme on Android

This is very possible; you define the URI scheme in your AndroidManifest.xml, using the <data> element. You setup an intent filter with the <data> element filled out, and you'll be able to create your own scheme. (More on intent filters and intent resolution here.)

Here's a short example:

<activity android:name=".MyUriActivity">
    <intent-filter>
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="myapp" android:host="path" />
    </intent-filter>
</activity>

As per how implicit intents work, you need to define at least one action and one category as well; here I picked VIEW as the action (though it could be anything), and made sure to add the DEFAULT category (as this is required for all implicit intents). Also notice how I added the category BROWSABLE - this is not necessary, but it will allow your URIs to be openable from the browser (a nifty feature).

Make JQuery UI Dialog automatically grow or shrink to fit its contents

var w = $('#dialogText').text().length;

$("#dialog").dialog('option', 'width', (w * 10));

did what i needed it to do for resizing the width of the dialog.

Mailbox unavailable. The server response was: 5.7.1 Unable to relay Error

I use Windows Server 2012 for hosting for a long time and it just stop working after a more than years without any problem. My solution was to add public IP address of the server to list of relays and enabled Windows Integrated Authentication.

I just made two changes and I don't which help.

Go to IIS 6 Manager

Go to IIS 6 Manager

Select properties of SMTP server

Select properties of SMTP server

On tab Access, select Relays

On tab Access, select Relays

Add your public IP address

Add your public IP address

Close the dialog and on the same tab click to Authentication button.

Add Integrated Windows Authentication

Add Integrated Windows Authentication

Maybe some step is not needed, but it works.

How to add additional fields to form before submit?

$('#form').append('<input type="text" value="'+yourValue+'" />');

How to check if object property exists with a variable holding the property name?

For own property :

var loan = { amount: 150 };
if(Object.prototype.hasOwnProperty.call(loan, "amount")) 
{ 
   //will execute
}

Note: using Object.prototype.hasOwnProperty is better than loan.hasOwnProperty(..), in case a custom hasOwnProperty is defined in the prototype chain (which is not the case here), like

var foo = {
      hasOwnProperty: function() {
        return false;
      },
      bar: 'Here be dragons'
    };

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty

To include inherited properties in the finding use the in operator: (but you must place an object at the right side of 'in', primitive values will throw error, e.g. 'length' in 'home' will throw error, but 'length' in new String('home') won't)

const yoshi = { skulk: true };
const hattori = { sneak: true };
const kuma = { creep: true };
if ("skulk" in yoshi) 
    console.log("Yoshi can skulk");

if (!("sneak" in yoshi)) 
    console.log("Yoshi cannot sneak");

if (!("creep" in yoshi)) 
    console.log("Yoshi cannot creep");

Object.setPrototypeOf(yoshi, hattori);

if ("sneak" in yoshi)
    console.log("Yoshi can now sneak");
if (!("creep" in hattori))
    console.log("Hattori cannot creep");

Object.setPrototypeOf(hattori, kuma);

if ("creep" in hattori)
    console.log("Hattori can now creep");
if ("creep" in yoshi)
    console.log("Yoshi can also creep");

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/in

Note: One may be tempted to use typeof and [ ] property accessor as the following code which doesn't work always ...

var loan = { amount: 150 };

loan.installment = undefined;

if("installment" in loan) // correct
{
    // will execute
}

if(typeof loan["installment"] !== "undefined") // incorrect
{
    // will not execute
}

Best practice for Django project working directory structure

As per the Django Project Skeleton, the proper directory structure that could be followed is :

[projectname]/                  <- project root
+-- [projectname]/              <- Django root
¦   +-- __init__.py
¦   +-- settings/
¦   ¦   +-- common.py
¦   ¦   +-- development.py
¦   ¦   +-- i18n.py
¦   ¦   +-- __init__.py
¦   ¦   +-- production.py
¦   +-- urls.py
¦   +-- wsgi.py
+-- apps/
¦   +-- __init__.py
+-- configs/
¦   +-- apache2_vhost.sample
¦   +-- README
+-- doc/
¦   +-- Makefile
¦   +-- source/
¦       +-- *snap*
+-- manage.py
+-- README.rst
+-- run/
¦   +-- media/
¦   ¦   +-- README
¦   +-- README
¦   +-- static/
¦       +-- README
+-- static/
¦   +-- README
+-- templates/
    +-- base.html
    +-- core
    ¦   +-- login.html
    +-- README

Refer https://django-project-skeleton.readthedocs.io/en/latest/structure.html for the latest directory structure.

Cannot implicitly convert type 'System.Linq.IQueryable' to 'System.Collections.Generic.IList'

You can replace IList<DzieckoAndOpiekun> resultV with var resultV.

Convert string to a variable name

assign is good, but I have not found a function for referring back to the variable you've created in an automated script. (as.name seems to work the opposite way). More experienced coders will doubtless have a better solution, but this solution works and is slightly humorous perhaps, in that it gets R to write code for itself to execute.

Say I have just assigned value 5 to x (var.name <- "x"; assign(var.name, 5)) and I want to change the value to 6. If I am writing a script and don't know in advance what the variable name (var.name) will be (which seems to be the point of the assign function), I can't simply put x <- 6 because var.name might have been "y". So I do:

var.name <- "x"
#some other code...
assign(var.name, 5)
#some more code...

#write a script file (1 line in this case) that works with whatever variable name
write(paste0(var.name, " <- 6"), "tmp.R")
#source that script file
source("tmp.R")
#remove the script file for tidiness
file.remove("tmp.R")

x will be changed to 6, and if the variable name was anything other than "x", that variable will similarly have been changed to 6.

Is it possible to change the content HTML5 alert messages?

Thank you guys for the help,

When I asked at first I didn't think it's even possible, but after your answers I googled and found this amazing tutorial:

http://blog.thomaslebrun.net/2011/11/html-5-how-to-customize-the-error-message-for-a-required-field/#.UsNN1BYrh2M

How can I return two values from a function in Python?

You can return more than one value using list also. Check the code below

def newFn():    #your function
  result = []    #defining blank list which is to be return
  r1 = 'return1'    #first value
  r2 = 'return2'    #second value
  result.append(r1)    #adding first value in list
  result.append(r2)    #adding second value in list
  return result    #returning your list

ret_val1 = newFn()[1]    #you can get any desired result from it
print ret_val1    #print/manipulate your your result

127 Return code from $?

A shell convention is that a successful executable should exit with the value 0. Anything else can be interpreted as a failure of some sort, on part of bash or the executable you that just ran. See also $PIPESTATUS and the EXIT STATUS section of the bash man page:

   For  the shell’s purposes, a command which exits with a zero exit status has succeeded.  An exit status
   of zero indicates success.  A non-zero exit status indicates failure.  When a command terminates  on  a
   fatal signal N, bash uses the value of 128+N as the exit status.
   If  a command is not found, the child process created to execute it returns a status of 127.  If a com-
   mand is found but is not executable, the return status is 126.

   If a command fails because of an error during expansion or redirection, the exit status is greater than
   zero.

   Shell  builtin  commands  return  a  status of 0 (true) if successful, and non-zero (false) if an error
   occurs while they execute.  All builtins return an exit status of 2 to indicate incorrect usage.

   Bash itself returns the exit status of the last command executed, unless  a  syntax  error  occurs,  in
   which case it exits with a non-zero value.  See also the exit builtin command below.

How do multiple clients connect simultaneously to one port, say 80, on a server?

Normally, for every connecting client the server forks a child process that communicates with the client (TCP). The parent server hands off to the child process an established socket that communicates back to the client.

When you send the data to a socket from your child server, the TCP stack in the OS creates a packet going back to the client and sets the "from port" to 80.

Bootstrap full responsive navbar with logo or brand name text

I checked and it worked for me.

<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1" style="margin-top:100px;"><!--style with margin-top according to your need-->
        <ul class="nav navbar-nav navbar-right">
            <li><a href="#">About</a></li>
            <li><a href="#">Services</a></li>
            <li><a href="#">Contact</a></li>
        </ul>
    </div>

Prevent typing non-numeric in input type number

I just had the same problem and discovered an alternative solution using the validation API - works without black magic in all major browsers (Chrome, Firefox, Safari) except IE. This solution simply prevents users from entering invalid values. I also included a fallback for IE, which is not nice but works at least.

Context: onInput function is called on input events, setInputValue is used to set the value of the input element, previousInputValue contains the last valid input value (updated in setInputValue calls).

    function onInput (event) {
        const inputValue = event.target.value;

        // badInput supported on validation api (except IE)
        // in IE it will be undefined, so we need strict value check
        const badInput = event.target.validity.badInput;

        // simply prevent modifying the value
        if (badInput === true) {
        // it's still possible to enter invalid values in an empty input, so we'll need this trick to prevent that
            if (previousInputValue === '') {
                setInputValue(' ');
                setTimeout(() => {
                    setInputValue('');
                }, 1);
            }
            return;
        }

        if (badInput === false) {
            setInputValue(inputValue);
            return;
        }

        // fallback case for IE and other abominations

        // remove everything from the string expect numbers, point and comma
        // replace comma with points (parseFloat works only with points)
        let stringVal = String(inputValue)
            .replace(/([^0-9.,])/g, '')
            .replace(/,/g, '.');

        // remove all but first point
        const pointIndex = stringVal.indexOf('.');
        if (pointIndex !== -1) {
            const pointAndBefore = stringVal.substring(0, pointIndex + 1);
            const afterPoint = stringVal.substring(pointIndex + 1);

            // removing all points after the first
            stringVal = `${pointAndBefore}${afterPoint.replace(/\./g, '')}`;
        }

        const float = parseFloat(stringVal);
        if (isNaN(float)) {
            // fallback to emptying the input if anything goes south
            setInputValue('');
            return;
        }
        setInputValue(stringVal);
}

Is there a command line command for verifying what version of .NET is installed

Unfortunately the best way would be to check for that directory. I am not sure what you mean but "actually installed" as .NET 3.5 uses the same CLR as .NET 3.0 and .NET 2.0 so all new functionality is wrapped up in new assemblies that live in that directory. Basically, if the directory is there then 3.5 is installed.

Only thing I would add is to find the dir this way for maximum flexibility:

%windir%\Microsoft.NET\Framework\v3.5

Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed

I had the same error, then I tried <asp:PostBackTrigger ControlID="xyz"/> instead of AsyncPostBackTrigger .This worked for me. It is because we don't want a partial postback.

Class type check in TypeScript

You can use the instanceof operator for this. From MDN:

The instanceof operator tests whether the prototype property of a constructor appears anywhere in the prototype chain of an object.

If you don't know what prototypes and prototype chains are I highly recommend looking it up. Also here is a JS (TS works similar in this respect) example which might clarify the concept:

_x000D_
_x000D_
    class Animal {_x000D_
        name;_x000D_
    _x000D_
        constructor(name) {_x000D_
            this.name = name;_x000D_
        }_x000D_
    }_x000D_
    _x000D_
    const animal = new Animal('fluffy');_x000D_
    _x000D_
    // true because Animal in on the prototype chain of animal_x000D_
    console.log(animal instanceof Animal); // true_x000D_
    // Proof that Animal is on the prototype chain_x000D_
    console.log(Object.getPrototypeOf(animal) === Animal.prototype); // true_x000D_
    _x000D_
    // true because Object in on the prototype chain of animal_x000D_
    console.log(animal instanceof Object); _x000D_
    // Proof that Object is on the prototype chain_x000D_
    console.log(Object.getPrototypeOf(Animal.prototype) === Object.prototype); // true_x000D_
    _x000D_
    console.log(animal instanceof Function); // false, Function not on prototype chain_x000D_
    _x000D_
    
_x000D_
_x000D_
_x000D_

The prototype chain in this example is:

animal > Animal.prototype > Object.prototype

How to change onClick handler dynamically?

I agree that using jQuery is the best option. You should also avoid using body's onload function and use jQuery's ready function instead. As for the event listeners, they should be functions that take one argument:

document.getElementById("foo").onclick = function (event){alert('foo');};

or in jQuery:

$('#foo').click(function(event) { alert('foo'); }

Declaring array of objects

Use array.push() to add an item to the end of the array.

var sample = new Array();
sample.push(new Object());

To do this n times use a for loop.

var n = 100;
var sample = new Array();
for (var i = 0; i < n; i++)
    sample.push(new Object());

Note that you can also substitute new Array() with [] and new Object() with {} so it becomes:

var n = 100;
var sample = [];
for (var i = 0; i < n; i++)
    sample.push({});

Unsigned values in C

In the hexadecimal it can't get a negative value. So it shows it like ffffffff.

The advantage to using the unsigned version (when you know the values contained will be non-negative) is that sometimes the computer will spot errors for you (the program will "crash" when a negative value is assigned to the variable).

Java regex capturing groups indexes

Capturing and grouping

Capturing group (pattern) creates a group that has capturing property.

A related one that you might often see (and use) is (?:pattern), which creates a group without capturing property, hence named non-capturing group.

A group is usually used when you need to repeat a sequence of patterns, e.g. (\.\w+)+, or to specify where alternation should take effect, e.g. ^(0*1|1*0)$ (^, then 0*1 or 1*0, then $) versus ^0*1|1*0$ (^0*1 or 1*0$).

A capturing group, apart from grouping, will also record the text matched by the pattern inside the capturing group (pattern). Using your example, (.*):, .* matches ABC and : matches :, and since .* is inside capturing group (.*), the text ABC is recorded for the capturing group 1.

Group number

The whole pattern is defined to be group number 0.

Any capturing group in the pattern start indexing from 1. The indices are defined by the order of the opening parentheses of the capturing groups. As an example, here are all 5 capturing groups in the below pattern:

(group)(?:non-capturing-group)(g(?:ro|u)p( (nested)inside)(another)group)(?=assertion)
|     |                       |          | |      |      ||       |     |
1-----1                       |          | 4------4      |5-------5     |
                              |          3---------------3              |
                              2-----------------------------------------2

The group numbers are used in back-reference \n in pattern and $n in replacement string.

In other regex flavors (PCRE, Perl), they can also be used in sub-routine calls.

You can access the text matched by certain group with Matcher.group(int group). The group numbers can be identified with the rule stated above.

In some regex flavors (PCRE, Perl), there is a branch reset feature which allows you to use the same number for capturing groups in different branches of alternation.

Group name

From Java 7, you can define a named capturing group (?<name>pattern), and you can access the content matched with Matcher.group(String name). The regex is longer, but the code is more meaningful, since it indicates what you are trying to match or extract with the regex.

The group names are used in back-reference \k<name> in pattern and ${name} in replacement string.

Named capturing groups are still numbered with the same numbering scheme, so they can also be accessed via Matcher.group(int group).

Internally, Java's implementation just maps from the name to the group number. Therefore, you cannot use the same name for 2 different capturing groups.

How to take keyboard input in JavaScript?

You can do this by registering an event handler on the document or any element you want to observe keystrokes on and examine the key related properties of the event object.

Example that works in FF and Webkit-based browsers:

document.addEventListener('keydown', function(event) {
    if(event.keyCode == 37) {
        alert('Left was pressed');
    }
    else if(event.keyCode == 39) {
        alert('Right was pressed');
    }
});

DEMO

Populate a datagridview with sql query results

This is suppose to be the safest and error pron query :

    public void Load_Data()
        {
            using (SqlConnection connection = new SqlConnection(DatabaseServices.connectionString)) //use your connection string here
            {
                var bindingSource = new BindingSource();
                string fetachSlidesRecentSQL = "select top (50) * from dbo.slides order by created_date desc";
                using (SqlDataAdapter dataAdapter = new SqlDataAdapter(fetachSlidesRecentSQL, connection))
                {
                    try
                    {
                       SqlCommandBuilder commandBuilder = new SqlCommandBuilder(dataAdapter);

                        DataTable table = new DataTable();
                        dataAdapter.Fill(table);
                        bindingSource.DataSource = table;
                        recent_slides_grd_view.ReadOnly = true;
                        recent_slides_grd_view.DataSource = bindingSource;
                    }
                    catch (SqlException ex)
                    {
                       MessageBox.Show(ex.Message.ToString(), "ERROR Loading");
                    }
                    finally
                    {
                        connection.Close();
                    }
                }

            }
        }

HTML5 Canvas: Zooming

One option is to use css zoom feature:

$("#canvas_id").css("zoom","x%"); 

How to get nth jQuery element

If you want to fetch particular element/node or tag in loop for e.g.

<p class="weekday" data-today="monday">Monday</p>
<p class="weekday" data-today="tuesday">Tuesday</p>
<p class="weekday" data-today="wednesday">Wednesday</p>
<p class="weekday" data-today="thursday">Thursday</p>

So, from above code loop is executed and we want particular field to select for that we have to use jQuery selection that can select only expecting element from above loop so, code will be

$('.weekdays:eq(n)');

e.g.

$('.weekdays:eq(0)');

as well as by other method

$('.weekday').find('p').first('.weekdays').next()/last()/prev();

but first method is more efficient when HTML <tag> has unique class name.

NOTE:Second method is use when their is no class name in target element or node.

for more follow https://api.jquery.com/eq/

Yahoo Finance All Currencies quote API Documentation

I'm developing an application that needs currency conversion, and been using Open Exchange Rates because I wouldn't be paying since the app is in testing. But as of September 2012 Open Exchange Rates is gonna be paid for non-personal, so I checked out that they were using the Yahoo Finance Webservice (the one that "doesn't exist") and looking for documentation on it got here, and opted to use YQL.

Using YQL with the Yahoo Finance table (yahoo.finance.quotes) linked by NT3RP, currencies appear with symbol="ISOCODE=X", for example: "ARS=X" for Argentine Peso, "AUD=X" for Australian Dollar. "USD=X" doesn't exist, but it would be 1, since the rest are rates against USD.

The "price" value on the OP API is in the field "LastTradePriceOnly" of the table. For my application I used the "Ask" field.

JavaScript property access: dot notation vs. brackets?

Let me add some more use case of the square-bracket notation. If you want to access a property say x-proxy in a object, then - will be interpreted wrongly. Their are some other cases too like space, dot, etc., where dot operation will not help you. Also if u have the key in a variable then only way to access the value of the key in a object is by bracket notation. Hope you get some more context.

Warning comparison between pointer and integer

In this line ...

if (*message == "\0") {

... as you can see in the warning ...

warning: comparison between pointer and integer
      ('int' and 'char *')

... you are actually comparing an int with a char *, or more specifically, an int with an address to a char.

To fix this, use one of the following:

if(*message == '\0') ...
if(message[0] == '\0') ...
if(!*message) ...

On a side note, if you'd like to compare strings you should use strcmp or strncmp, found in string.h.

CSS Selector "(A or B) and C"?

No. Standard CSS does not provide the kind of thing you're looking for.

However, you might want to look into LESS and SASS.

These are two projects which aim to extend default CSS syntax by introducing additional features, including variables, nested rules, and other enhancements.

They allow you to write much more structured CSS code, and either of them will almost certainly solve your particular use case.

Of course, none of the browsers support their extended syntax (especially since the two projects each have different syntax and features), but what they do is provide a "compiler" which converts your LESS or SASS code into standard CSS, which you can then deploy on your site.

How to clear PermGen space Error in tomcat

To complement Michael's answer, and according to this answer, a safe way to deal with the problem is to use the following arguments:

-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:+UseConcMarkSweepGC

How might I extract the property values of a JavaScript object into an array?

Using the accepted answer and knowing that Object.values() is proposed in ECMAScript 2017 Draft you can extend Object with method:

if(Object.values == null) {
    Object.values = function(obj) {
        var arr, o;
        arr = new Array();
        for(o in obj) { arr.push(obj[o]); }
        return arr;
    }
}

Using `window.location.hash.includes` throws “Object doesn't support property or method 'includes'” in IE11

IE11 does implement String.prototype.includes so why not using the official Polyfill?

  if (!String.prototype.includes) {
    String.prototype.includes = function(search, start) {
      if (typeof start !== 'number') {
        start = 0;
      }

      if (start + search.length > this.length) {
        return false;
      } else {
        return this.indexOf(search, start) !== -1;
      }
    };
  }

Source: polyfill source

What's the difference between commit() and apply() in SharedPreferences

tl;dr:

  • commit() writes the data synchronously (blocking the thread its called from). It then informs you about the success of the operation.
  • apply() schedules the data to be written asynchronously. It does not inform you about the success of the operation.
  • If you save with apply() and immediately read via any getX-method, the new value will be returned!
  • If you called apply() at some point and it's still executing, any calls to commit() will block until all past apply-calls and the current commit-call are finished.

More in-depth information from the SharedPreferences.Editor Documentation:

Unlike commit(), which writes its preferences out to persistent storage synchronously, apply() commits its changes to the in-memory SharedPreferences immediately but starts an asynchronous commit to disk and you won't be notified of any failures. If another editor on this SharedPreferences does a regular commit() while a apply() is still outstanding, the commit() will block until all async commits are completed as well as the commit itself.

As SharedPreferences instances are singletons within a process, it's safe to replace any instance of commit() with apply() if you were already ignoring the return value.

The SharedPreferences.Editor interface isn't expected to be implemented directly. However, if you previously did implement it and are now getting errors about missing apply(), you can simply call commit() from apply().

How can I delete a service in Windows?

We can do it in two different ways

Remove Windows Service via Registry

Its very easy to remove a service from registry if you know the right path. Here is how I did that:

  1. Run Regedit or Regedt32

  2. Go to the registry entry "HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services"

  3. Look for the service that you want delete and delete it. You can look at the keys to know what files the service was using and delete them as well (if necessary).

Delete Windows Service via Command Window

Alternatively, you can also use command prompt and delete a service using following command:

sc delete

You can also create service by using following command

sc create "MorganTechService" binpath= "C:\Program Files\MorganTechSPace\myservice.exe"

Note: You may have to reboot the system to get the list updated in service manager.

Unable to start debugging on the web server. Could not start ASP.NET debugging VS 2010, II7, Win 7 x64

Had the same issue trying to debug a DNN (Dot Net Nuke) module. Turned out you need to have compilation debug="true":

<compilation debug="true" strict="false" targetFramework="4.0"> 

in your web.config. By default it is false in DNN. Original source here: http://www.dnnsoftware.com/forums/forumid/111/postid/189880/scope/posts

Read the package name of an Android APK

You get the package name programmatically using :

packageManager.getPackageArchiveInfo(apkFilePath, 0)?.packageName

Index was out of range. Must be non-negative and less than the size of the collection parameter name:index

what this means ? is there any problem in my code

It means that you are accessing a location or index which is not present in collection.

To find this, Make sure your Gridview has 5 columns as you are using it's 5th column by this line

dataGridView1.Columns[4].Name = "Amount";

Here is the image which shows the elements of an array. So if your gridview has less column then the (index + 1) by which you are accessing it, then this exception arises.

enter image description here

When should we use Observer and Observable?

Observer pattern is used when there is one-to-many relationship between objects such as if one object is modified, its dependent objects are to be notified automatically.

json.decoder.JSONDecodeError: Extra data: line 2 column 1 (char 190)

You have two records in your json file, and json.loads() is not able to decode more than one. You need to do it record by record.

See Python json.loads shows ValueError: Extra data

OR you need to reformat your json to contain an array:

{
    "foo" : [
       {"name": "XYZ", "address": "54.7168,94.0215", "country_of_residence": "PQR", "countries": "LMN;PQRST", "date": "28-AUG-2008", "type": null},
       {"name": "OLMS", "address": null, "country_of_residence": null, "countries": "Not identified;No", "date": "23-FEB-2017", "type": null}
    ]
}

would be acceptable again. But there cannot be several top level objects.

Pretty-Printing JSON with PHP

Simple way for php>5.4: like in Facebook graph

$Data = array('a' => 'apple', 'b' => 'banana', 'c' => 'catnip');
$json= json_encode($Data, JSON_PRETTY_PRINT);
header('Content-Type: application/json');
print_r($json);

Result in browser

{
    "a": "apple",
    "b": "banana",
    "c": "catnip"
}

Regular Expression - 2 letters and 2 numbers in C#

This should get you for starting with two letters and ending with two numbers.

[A-Za-z]{2}(.*)[0-9]{2}

If you know it will always be just two and two you can

[A-Za-z]{2}[0-9]{2}

Pandas left outer join multiple dataframes on multiple columns

Merge them in two steps, df1 and df2 first, and then the result of that to df3.

In [33]: s1 = pd.merge(df1, df2, how='left', on=['Year', 'Week', 'Colour'])

I dropped year from df3 since you don't need it for the last join.

In [39]: df = pd.merge(s1, df3[['Week', 'Colour', 'Val3']],
                       how='left', on=['Week', 'Colour'])

In [40]: df
Out[40]: 
   Year Week Colour  Val1  Val2 Val3
0  2014    A    Red    50   NaN  NaN
1  2014    B    Red    60   NaN   60
2  2014    B  Black    70   100   10
3  2014    C    Red    10    20  NaN
4  2014    D  Green    20   NaN   20

[5 rows x 6 columns]

XML Schema How to Restrict Attribute by Enumeration

New answer to old question

None of the existing answers to this old question address the real problem.

The real problem was that xs:complexType cannot directly have a xs:extension as a child in XSD. The fix is to use xs:simpleContent first. Details follow...


Your XML,

<price currency="euros">20000.00</price>

will be valid against either of the following corrected XSDs:

Locally defined attribute type

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

  <xs:element name="price">
    <xs:complexType>
      <xs:simpleContent>
        <xs:extension base="xs:decimal">
          <xs:attribute name="currency">
            <xs:simpleType>
              <xs:restriction base="xs:string">
                <xs:enumeration value="pounds" />
                <xs:enumeration value="euros" />
                <xs:enumeration value="dollars" />
              </xs:restriction>
            </xs:simpleType>
          </xs:attribute>
        </xs:extension>
      </xs:simpleContent>
    </xs:complexType>
  </xs:element>
</xs:schema>

Globally defined attribute type

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

  <xs:simpleType name="currencyType">
    <xs:restriction base="xs:string">
      <xs:enumeration value="pounds" />
      <xs:enumeration value="euros" />
      <xs:enumeration value="dollars" />
    </xs:restriction>
  </xs:simpleType>

  <xs:element name="price">
    <xs:complexType>
      <xs:simpleContent>
        <xs:extension base="xs:decimal">
          <xs:attribute name="currency" type="currencyType"/>
        </xs:extension>
      </xs:simpleContent>
    </xs:complexType>
  </xs:element>
</xs:schema>

Notes

  • As commented by @Paul, these do change the content type of price from xs:string to xs:decimal, but this is not strictly necessary and was not the real problem.
  • As answered by @user998692, you could separate out the definition of currency, and you could change to xs:decimal, but this too was not the real problem.

The real problem was that xs:complexType cannot directly have a xs:extension as a child in XSD; xs:simpleContent is needed first.

A related matter (that wasn't asked but may have confused other answers):

How could price be restricted given that it has an attribute?

In this case, a separate, global definition of priceType would be needed; it is not possible to do this with only local type definitions.

How to restrict element content when element has attribute

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

  <xs:simpleType name="priceType">  
    <xs:restriction base="xs:decimal">  
      <xs:minInclusive value="0.00"/>  
      <xs:maxInclusive value="99999.99"/>  
    </xs:restriction>  
  </xs:simpleType>

  <xs:element name="price">
    <xs:complexType>
      <xs:simpleContent>
        <xs:extension base="priceType">
          <xs:attribute name="currency">
            <xs:simpleType>
              <xs:restriction base="xs:string">
                <xs:enumeration value="pounds" />
                <xs:enumeration value="euros" />
                <xs:enumeration value="dollars" />
              </xs:restriction>
            </xs:simpleType>
          </xs:attribute>
        </xs:extension>
      </xs:simpleContent>
    </xs:complexType>
  </xs:element>
</xs:schema>

Using GroupBy, Count and Sum in LINQ Lambda Expressions

var boxSummary = from b in boxes
                 group b by b.Owner into g
                 let nrBoxes = g.Count()
                 let totalWeight = g.Sum(w => w.Weight)
                 let totalVolume = g.Sum(v => v.Volume)
                 select new { Owner = g.Key, Boxes = nrBoxes,
                              TotalWeight = totalWeight,
                              TotalVolume = totalVolume }

convert string to specific datetime format?

More formats:

 require 'date'

 date = "01/07/2016 09:17AM"
 DateTime.parse(date).strftime("%A, %b %d")
 #=> Friday, Jul 01

 DateTime.parse(date).strftime("%m/%d/%Y")
 #=> 07/01/2016

 DateTime.parse(date).strftime("%m-%e-%y %H:%M")
 #=> 07- 1-16 09:17

 DateTime.parse(date).strftime("%b %e")
 #=> Jul  1

 DateTime.parse(date).strftime("%l:%M %p")
 #=>  9:17 AM

 DateTime.parse(date).strftime("%B %Y")
 #=> July 2016
 DateTime.parse(date).strftime("%b %d, %Y")
 #=> Jul 01, 2016
 DateTime.parse(date).strftime("%a, %e %b %Y %H:%M:%S %z")
 #=> Fri,  1 Jul 2016 09:17:00 +0200
 DateTime.parse(date).strftime("%Y-%m-%dT%l:%M:%S%z")
 #=> 2016-07-01T 9:17:00+0200
 DateTime.parse(date).strftime("%I:%M:%S %p")
 #=> 09:17:00 AM
 DateTime.parse(date).strftime("%H:%M:%S")
 #=> 09:17:00
 DateTime.parse(date).strftime("%e %b %Y %H:%M:%S%p")
 #=>  1 Jul 2016 09:17:00AM
 DateTime.parse(date).strftime("%d.%m.%y")
 #=> 01.07.16
 DateTime.parse(date).strftime("%A, %d %b %Y %l:%M %p")
 #=> Friday, 01 Jul 2016  9:17 AM

php implode (101) with quotes

Don't forget to escape your data! If you want to put data in a CSV file without fputcsv function or put it in a SQL query use this code:

$comma_separated = "'" . implode("','", array_map('addslashes', $array)) . "'";

This code avoids SQL injection or data fragmentation when input array contains single quotation or backslash characters.

Testing pointers for validity (C/C++)

AFAIK there is no way. You should try to avoid this situation by always setting pointers to NULL after freeing memory.

Remove padding or margins from Google Charts

I am quite late but any user searching for this can get help from it. Inside the options you can pass a new parameter called chartArea.

        var options = {
        chartArea:{left:10,top:20,width:"100%",height:"100%"}
    };

Left and top options will define the amount of padding from left and top. Hope this will help.

How can I compare two strings in java and define which of them is smaller than the other alphabetically?

You can use

str1.compareTo(str2);

If str1 is lexicographically less than str2, a negative number will be returned, 0 if equal or a positive number if str1 is greater.

E.g.,

"a".compareTo("b"); // returns a negative number, here -1
"a".compareTo("a"); // returns  0
"b".compareTo("a"); // returns a positive number, here 1
"b".compareTo(null); // throws java.lang.NullPointerException

Conda command is not recognized on Windows 10

To prevent having further issues with SSL you should add all those to Path :

 SETX PATH "%PATH%;C:\<path>\Anaconda3;C:\<path>\Anaconda3\Scripts;C:\<path>\Anaconda3\Library\bin"

Requests (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.") Error in PyCharm requesting website

Using C# to check if string contains a string in string array

Try:

String[] val = { "helloword1", "orange", "grape", "pear" };
String sep = "";
string stringToCheck = "word1";

bool match = String.Join(sep,val).Contains(stringToCheck);
bool anothermatch = val.Any(s => s.Contains(stringToCheck));

How to set base url for rest in spring boot?

With spring-boot 2.x you can configure in application.properties:

spring.mvc.servlet.path=/api

Tomcat Server not starting with in 45 seconds

I got the solution for your requirement.

I'm also getting the same error in my eclipse Luna.

Go to Windows option -> select preference.

Than Select General -> Network Connection.

Than select the Active Provider as Manual.

Then restart the tomcat and run. It will work.

Hope it will help you.

Left align block of equations

You can use \begin{flalign}, like the example bellow:

\begin{flalign}
    &f(x) = -1.25x^{2} + 1.5x&
\end{flalign}

How do I run Redis on Windows?

enter image description hereenter image description hereenter image description here

VARY EASY:(NO ANY CAMMAN OR NOT GOING TO ANY LINK,ONLY FOLLOW THIS STEP ,FOR ALL VERSION)   
             FIRST INSTALL REDIS 
                -->>AFTER OPEN TASKBAR
                -->>OPEN SERVICE(taskbar service)
                -->>CHOOSE REDIS 
                -->>RIGTH CLICK ON REDIS SERVICE AND OPEN SERVICE(VIEW IMAGES) 
                -->>CLICK ON START OR RESTART.(ALSO SET AUTOSTART)

Is there a Python caching library?

You can use my simple solution to the problem. It is really straightforward, nothing fancy:

class MemCache(dict):
    def __init__(self, fn):
        dict.__init__(self)
        self.__fn = fn

    def __getitem__(self, item):
        if item not in self:
            dict.__setitem__(self, item, self.__fn(item))
        return dict.__getitem__(self, item)

mc = MemCache(lambda x: x*x)

for x in xrange(10):
    print mc[x]

for x in xrange(10):
    print mc[x]

It indeed lacks expiration funcionality, but you can easily extend it with specifying a particular rule in MemCache c-tor.

Hope code is enough self-explanatory, but if not, just to mention, that cache is being passed a translation function as one of its c-tor params. It's used in turn to generate cached output regarding the input.

Hope it helps

Setting size for icon in CSS

You could override the framework CSS (I guess you're using one) and set the size as you want, like this:

.pnx-msg-icon pnx-icon-msg-warning {
    width: 24px !important;
    height: 24px !important;
}

The "!important" property will make sure your code has priority to the framework's code. Make sure you are overriding the correct property, I don't know how the framework is working, this is just an example of !important usage.

Stored Procedure parameter default value - is this a constant or a variable

It has to be a constant - the value has to be computable at the time that the procedure is created, and that one computation has to provide the value that will always be used.

Look at the definition of sys.all_parameters:

default_value sql_variant If has_default_value is 1, the value of this column is the value of the default for the parameter; otherwise, NULL.

That is, whatever the default for a parameter is, it has to fit in that column.


As Alex K pointed out in the comments, you can just do:

CREATE PROCEDURE [dbo].[problemParam] 
    @StartDate INT = NULL,
    @EndDate INT = NULL
AS  
BEGIN
   SET @StartDate = COALESCE(@StartDate,CONVERT(INT,(CONVERT(CHAR(8),GETDATE()-130,112))))

provided that NULL isn't intended to be a valid value for @StartDate.


As to the blog post you linked to in the comments - that's talking about a very specific context - that, the result of evaluating GETDATE() within the context of a single query is often considered to be constant. I don't know of many people (unlike the blog author) who would consider a separate expression inside a UDF to be part of the same query as the query that calls the UDF.

How to enable CORS in apache tomcat

CORS support in Tomcat is provided via a filter. You need to add this filter to your web.xml file and configure it to match your requirements. Full details on the configuration options available can be found in the Tomcat Documentation.

Finding all possible combinations of numbers to reach a given sum

Another python solution would be to use the itertools.combinations module as follows:

#!/usr/local/bin/python

from itertools import combinations

def find_sum_in_list(numbers, target):
    results = []
    for x in range(len(numbers)):
        results.extend(
            [   
                combo for combo in combinations(numbers ,x)  
                    if sum(combo) == target
            ]   
        )   

    print results

if __name__ == "__main__":
    find_sum_in_list([3,9,8,4,5,7,10], 15)

Output: [(8, 7), (5, 10), (3, 8, 4), (3, 5, 7)]

How to convert string to XML using C#

xDoc.LoadXML("<head><body><Inner> welcome </head> </Inner> <Outer> Bye</Outer>                    
                    </body></head>");

Detect changes in the DOM

Use the MutationObserver interface as shown in Gabriele Romanato's blog

Chrome 18+, Firefox 14+, IE 11+, Safari 6+

// The node to be monitored
var target = $( "#content" )[0];

// Create an observer instance
var observer = new MutationObserver(function( mutations ) {
  mutations.forEach(function( mutation ) {
    var newNodes = mutation.addedNodes; // DOM NodeList
    if( newNodes !== null ) { // If there are new nodes added
        var $nodes = $( newNodes ); // jQuery set
        $nodes.each(function() {
            var $node = $( this );
            if( $node.hasClass( "message" ) ) {
                // do something
            }
        });
    }
  });    
});

// Configuration of the observer:
var config = { 
    attributes: true, 
    childList: true, 
    characterData: true 
};

// Pass in the target node, as well as the observer options
observer.observe(target, config);

// Later, you can stop observing
observer.disconnect();

How to select a dropdown value in Selenium WebDriver using Java

Just wrap your WebElement into Select Object as shown below

Select dropdown = new Select(driver.findElement(By.id("identifier")));

Once this is done you can select the required value in 3 ways. Consider an HTML file like this

<html>
<body>
<select id = "designation">
<option value = "MD">MD</option>
<option value = "prog"> Programmer </option>
<option value = "CEO"> CEO </option>
</option>
</select>
<body>
</html>

Now to identify dropdown do

Select dropdown = new Select(driver.findElement(By.id("designation")));

To select its option say 'Programmer' you can do

dropdown.selectByVisibleText("Programmer ");

or

dropdown.selectByIndex(1);

or

 dropdown.selectByValue("prog");

BasicHttpBinding vs WsHttpBinding vs WebHttpBinding

You're comparing apples to oranges here:

  • webHttpBinding is the REST-style binding, where you basically just hit a URL and get back a truckload of XML or JSON from the web service

  • basicHttpBinding and wsHttpBinding are two SOAP-based bindings which is quite different from REST. SOAP has the advantage of having WSDL and XSD to describe the service, its methods, and the data being passed around in great detail (REST doesn't have anything like that - yet). On the other hand, you can't just browse to a wsHttpBinding endpoint with your browser and look at XML - you have to use a SOAP client, e.g. the WcfTestClient or your own app.

So your first decision must be: REST vs. SOAP (or you can expose both types of endpoints from your service - that's possible, too).

Then, between basicHttpBinding and wsHttpBinding, there differences are as follows:

  • basicHttpBinding is the very basic binding - SOAP 1.1, not much in terms of security, not much else in terms of features - but compatible to just about any SOAP client out there --> great for interoperability, weak on features and security

  • wsHttpBinding is the full-blown binding, which supports a ton of WS-* features and standards - it has lots more security features, you can use sessionful connections, you can use reliable messaging, you can use transactional control - just a lot more stuff, but wsHttpBinding is also a lot *heavier" and adds a lot of overhead to your messages as they travel across the network

For an in-depth comparison (including a table and code examples) between the two check out this codeproject article: Differences between BasicHttpBinding and WsHttpBinding

How to add image in Flutter

Create your assets directory the same as lib level

like this

projectName
 -android
 -ios
 -lib
 -assets
 -pubspec.yaml

then your pubspec.yaml like

  flutter:
  assets:
    - assets/images/

now you can use Image.asset("/assets/images/")

AES Encrypt and Decrypt

Update Swift 4.2

Here, for instance, we encrypt a string to base64encoded string. And then we decrypt the same to a readable string. (That would be same as our input string).

In my case, I use this to encrypt a string and embed that to QR Code. Then another party scan that and decrypt the same. So intermediate won't understand the QR codes.

Step 1: Encrypt a string "Encrypt My Message 123"

Step 2: Encrypted base64Encoded string : +yvNjiD7F9/JKmqHTc/Mjg== (The same printed on QR code)

Step 3: Scan and decrypt the string "+yvNjiD7F9/JKmqHTc/Mjg=="

Step 4: It comes final result - "Encrypt My Message 123"

Functions for Encrypt & Decrypt

func encryption(stringToEncrypt: String) -> String{
    let key = "MySecretPKey"
    //let iv = "92c9d2c07a9f2e0a"
    let data = stringToEncrypt.data(using: .utf8)
    let keyD = key.data(using: .utf8)
    let encr = (data as NSData?)!.aes128EncryptedData(withKey: keyD)
    let base64String: String = (encr as NSData?)!.base64EncodedString(options: NSData.Base64EncodingOptions(rawValue: 0))
    print(base64String)
    return base64String
}

func decryption(encryptedString:String) -> String{
    let key = "MySecretPKey"
    //let iv = "92c9d2c07a9f2e0a"
    let keyD = key.data(using: .utf8)
    let decrpStr = NSData(base64Encoded: encryptedString, options: NSData.Base64DecodingOptions(rawValue: 0))
    let dec = (decrpStr)!.aes128DecryptedData(withKey: keyD)
    let backToString = String(data: dec!, encoding: String.Encoding.utf8)
    print(backToString!)
    return backToString!
}

Usage:

    let enc = encryption(stringToEncrypt: "Encrypt My Message 123")
    let decryptedString = decryption(encryptedString: enc)
    print(decryptedString) 

Classes for supporting AES encrypting functions, these are written in Objective-C. So for swift, you need to use bridge header to support these.

Class Name: NSData+AES.h

#import <Foundation/Foundation.h>

@interface NSData (AES)

- (NSData *)AES128EncryptedDataWithKey:(NSData *)key;
- (NSData *)AES128DecryptedDataWithKey:(NSData *)key;
- (NSData *)AES128EncryptedDataWithKey:(NSData *)key iv:(NSData *)iv;
- (NSData *)AES128DecryptedDataWithKey:(NSData *)key iv:(NSData *)iv;

@end

Class Name: NSData+AES.m

#import "NSData+AES.h"
#import <CommonCrypto/CommonCryptor.h>

@implementation NSData (AES)

- (NSData *)AES128EncryptedDataWithKey:(NSData *)key
{
    return [self AES128EncryptedDataWithKey:key iv:nil];
}

- (NSData *)AES128DecryptedDataWithKey:(NSData *)key
{
    return [self AES128DecryptedDataWithKey:key iv:nil];
}

- (NSData *)AES128EncryptedDataWithKey:(NSData *)key iv:(NSData *)iv
{
    return [self AES128Operation:kCCEncrypt key:key iv:iv];
}

- (NSData *)AES128DecryptedDataWithKey:(NSData *)key iv:(NSData *)iv
{
    return [self AES128Operation:kCCDecrypt key:key iv:iv];
}

- (NSData *)AES128Operation:(CCOperation)operation key:(NSData *)key iv:(NSData *)iv
{

    NSUInteger dataLength = [self length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(operation,
                                          kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding | kCCOptionECBMode,
                                          key.bytes,
                                          kCCBlockSizeAES128,
                                          iv.bytes,
                                          [self bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
    }
    free(buffer);
    return nil;
}

@end

I hope that helps.

Thanks!!!

How to quit a java app from within the program

System.exit() is usually not the best way, but it depends on your application.

The usual way of ending an application is by exiting the main() method. This does not work when there are other non-deamon threads running, as is usual for applications with a graphical user interface (AWT, Swing etc.). For these applications, you either find a way to end the GUI event loop (don't know if that is possible with the AWT or Swing), or invoke System.exit().

Why is git push gerrit HEAD:refs/for/master used instead of git push origin master

In order to avoid having to fully specify the git push command you could alternatively modify your git config file:

[remote "gerrit"]
    url = https://your.gerrit.repo:44444/repo
    fetch = +refs/heads/master:refs/remotes/origin/master
    push = refs/heads/master:refs/for/master

Now you can simply:

git fetch gerrit
git push gerrit

This is according to Gerrit

Understanding React-Redux and mapStateToProps()

React-Redux connect is used to update store for every actions.

import { connect } from 'react-redux';

const AppContainer = connect(  
  mapStateToProps,
  mapDispatchToProps
)(App);

export default AppContainer;

It's very simply and clearly explained in this blog.

You can clone github project or copy paste the code from that blog to understand the Redux connect.

What does "export" do in shell programming?

Exported variables such as $HOME and $PATH are available to (inherited by) other programs run by the shell that exports them (and the programs run by those other programs, and so on) as environment variables. Regular (non-exported) variables are not available to other programs.

$ env | grep '^variable='
$                                 # No environment variable called variable
$ variable=Hello                  # Create local (non-exported) variable with value
$ env | grep '^variable='
$                                 # Still no environment variable called variable
$ export variable                 # Mark variable for export to child processes
$ env | grep '^variable='
variable=Hello
$
$ export other_variable=Goodbye   # create and initialize exported variable
$ env | grep '^other_variable='
other_variable=Goodbye
$

For more information, see the entry for the export builtin in the GNU Bash manual, and also the sections on command execution environment and environment.

Note that non-exported variables will be available to subshells run via ( ... ) and similar notations because those subshells are direct clones of the main shell:

$ othervar=present
$ (echo $othervar; echo $variable; variable=elephant; echo $variable)
present
Hello
elephant
$ echo $variable
Hello
$

The subshell can change its own copy of any variable, exported or not, and may affect the values seen by the processes it runs, but the subshell's changes cannot affect the variable in the parent shell, of course.

Some information about subshells can be found under command grouping and command execution environment in the Bash manual.

How can I change the image displayed in a UIImageView programmatically?

Example in Swift:

import UIKit

class ViewController: UIViewController {

    @IBOutlet var myUIImageView: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func myAction(sender: UIButton) {
        let newImg: UIImage? = UIImage(named: "profile-picture-name")
        self.myUIImageView.image = newImg
    }

    @IBAction func myAction2(sender: UIButton) {
        self.myUIImageView.image = nil
        self.myUIImageView.image = UIImage(data: NSData(contentsOfURL: NSURL(string: "http://url/image.png")!)!)
    }

}

How do I pass data between Activities in Android application?

Use a global class:

public class GlobalClass extends Application
{
    private float vitamin_a;


    public float getVitaminA() {
        return vitamin_a;
    }

    public void setVitaminA(float vitamin_a) {
        this.vitamin_a = vitamin_a;
    }
}

You can call the setters and the getters of this class from all other classes. Do do that, you need to make a GlobalClass-Object in every Actitity:

GlobalClass gc = (GlobalClass) getApplication();

Then you can call for example:

gc.getVitaminA()

How to draw checkbox or tick mark in GitHub Markdown table?

Following is how I draw a checkbox in a table!

| Checkbox Experiments | [ ] unchecked header  | [x] checked header  |
| ---------------------|:---------------------:|:-------------------:|
| checkbox             | [ ] row               | [x] row             |


Displays like this:
enter image description here

How to use PDO to fetch results array in PHP?

Take a look at the PDOStatement.fetchAll method. You could also use fetch in an iterator pattern.

Code sample for fetchAll, from the PHP documentation:

<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

/* Fetch all of the remaining rows in the result set */
print("Fetch all of the remaining rows in the result set:\n");
$result = $sth->fetchAll(\PDO::FETCH_ASSOC);
print_r($result);

Results:

Array
(
    [0] => Array
        (
            [NAME] => pear
            [COLOUR] => green
        )

    [1] => Array
        (
            [NAME] => watermelon
            [COLOUR] => pink
        )
)

Is Ruby pass by reference or by value?

In traditional terminology, Ruby is strictly pass-by-value. But that's not really what you're asking here.

Ruby doesn't have any concept of a pure, non-reference value, so you certainly can't pass one to a method. Variables are always references to objects. In order to get an object that won't change out from under you, you need to dup or clone the object you're passed, thus giving an object that nobody else has a reference to. (Even this isn't bulletproof, though — both of the standard cloning methods do a shallow copy, so the instance variables of the clone still point to the same objects that the originals did. If the objects referenced by the ivars mutate, that will still show up in the copy, since it's referencing the same objects.)

Integer division with remainder in JavaScript?

I normally use:

const quotient =  (a - a % b) / b;
const remainder = a % b;

It's probably not the most elegant, but it works.

Best practice when adding whitespace in JSX

If the goal is to seperate two elements, you can use CSS like below:

A<span style={{paddingLeft: '20px'}}>B</span>

How can I use pickle to save a dict?

import pickle

dictobj = {'Jack' : 123, 'John' : 456}

filename = "/foldername/filestore"

fileobj = open(filename, 'wb')

pickle.dump(dictobj, fileobj)

fileobj.close()

What does it mean to inflate a view from an xml file?

When you write an XML layout, it will be inflated by the Android OS which basically means that it will be rendered by creating view object in memory. Let's call that implicit inflation (the OS will inflate the view for you). For instance:

class Name extends Activity{
    public void onCreate(){
         // the OS will inflate the your_layout.xml
         // file and use it for this activity
         setContentView(R.layout.your_layout);
    }
}

You can also inflate views explicitly by using the LayoutInflater. In that case you have to:

  1. Get an instance of the LayoutInflater
  2. Specify the XML to inflate
  3. Use the returned View
  4. Set the content view with returned view (above)

For instance:

LayoutInflater inflater = LayoutInflater.from(YourActivity.this); // 1
View theInflatedView = inflater.inflate(R.layout.your_layout, null); // 2 and 3
setContentView(theInflatedView) // 4

Putting text in top left corner of matplotlib plot

One solution would be to use the plt.legend function, even if you don't want an actual legend. You can specify the placement of the legend box by using the loc keyterm. More information can be found at this website but I've also included an example showing how to place a legend:

ax.scatter(xa,ya, marker='o', s=20, c="lightgreen", alpha=0.9)
ax.scatter(xb,yb, marker='o', s=20, c="dodgerblue", alpha=0.9)
ax.scatter(xc,yc marker='o', s=20, c="firebrick", alpha=1.0)
ax.scatter(xd,xd,xd, marker='o', s=20, c="goldenrod", alpha=0.9)
line1 = Line2D(range(10), range(10), marker='o', color="goldenrod")
line2 = Line2D(range(10), range(10), marker='o',color="firebrick")
line3 = Line2D(range(10), range(10), marker='o',color="lightgreen")
line4 = Line2D(range(10), range(10), marker='o',color="dodgerblue")
plt.legend((line1,line2,line3, line4),('line1','line2', 'line3', 'line4'),numpoints=1, loc=2) 

Note that because loc=2, the legend is in the upper-left corner of the plot. And if the text overlaps with the plot, you can make it smaller by using legend.fontsize, which will then make the legend smaller.

"Large data" workflows using pandas

This is the case for pymongo. I have also prototyped using sql server, sqlite, HDF, ORM (SQLAlchemy) in python. First and foremost pymongo is a document based DB, so each person would be a document (dict of attributes). Many people form a collection and you can have many collections (people, stock market, income).

pd.dateframe -> pymongo Note: I use the chunksize in read_csv to keep it to 5 to 10k records(pymongo drops the socket if larger)

aCollection.insert((a[1].to_dict() for a in df.iterrows()))

querying: gt = greater than...

pd.DataFrame(list(mongoCollection.find({'anAttribute':{'$gt':2887000, '$lt':2889000}})))

.find() returns an iterator so I commonly use ichunked to chop into smaller iterators.

How about a join since I normally get 10 data sources to paste together:

aJoinDF = pandas.DataFrame(list(mongoCollection.find({'anAttribute':{'$in':Att_Keys}})))

then (in my case sometimes I have to agg on aJoinDF first before its "mergeable".)

df = pandas.merge(df, aJoinDF, on=aKey, how='left')

And you can then write the new info to your main collection via the update method below. (logical collection vs physical datasources).

collection.update({primarykey:foo},{key:change})

On smaller lookups, just denormalize. For example, you have code in the document and you just add the field code text and do a dict lookup as you create documents.

Now you have a nice dataset based around a person, you can unleash your logic on each case and make more attributes. Finally you can read into pandas your 3 to memory max key indicators and do pivots/agg/data exploration. This works for me for 3 million records with numbers/big text/categories/codes/floats/...

You can also use the two methods built into MongoDB (MapReduce and aggregate framework). See here for more info about the aggregate framework, as it seems to be easier than MapReduce and looks handy for quick aggregate work. Notice I didn't need to define my fields or relations, and I can add items to a document. At the current state of the rapidly changing numpy, pandas, python toolset, MongoDB helps me just get to work :)

Is it possible to use if...else... statement in React render function?

Not exactly like that, but there are workarounds. There's a section in React's docs about conditional rendering that you should take a look. Here's an example of what you could do using inline if-else.

render() {
  const isLoggedIn = this.state.isLoggedIn;
  return (
    <div>
      {isLoggedIn ? (
        <LogoutButton onClick={this.handleLogoutClick} />
      ) : (
        <LoginButton onClick={this.handleLoginClick} />
      )}
    </div>
  );
}

You can also deal with it inside the render function, but before returning the jsx.

if (isLoggedIn) {
  button = <LogoutButton onClick={this.handleLogoutClick} />;
} else {
  button = <LoginButton onClick={this.handleLoginClick} />;
}

return (
  <div>
    <Greeting isLoggedIn={isLoggedIn} />
    {button}
  </div>
);

It's also worth mentioning what ZekeDroid brought up in the comments. If you're just checking for a condition and don't want to render a particular piece of code that doesn't comply, you can use the && operator.

  return (
    <div>
      <h1>Hello!</h1>
      {unreadMessages.length > 0 &&
        <h2>
          You have {unreadMessages.length} unread messages.
        </h2>
      }
    </div>
  );

How to Execute SQL Server Stored Procedure in SQL Developer?

Select * from Table name ..i.e(are you save table name in sql(TEST) k.

Select * from TEST then you will execute your project.

What is the problem with shadowing names defined in outer scopes?

Do this:

data = [4, 5, 6]

def print_data():
    global data
    print(data)

print_data()

Javascript: how to validate dates in format MM-DD-YYYY?

This function will validate the date to see if it's correct or if it's in the proper format of: DD/MM/YYYY.

function isValidDate(date)
{
    var matches = /^(\d{2})[-\/](\d{2})[-\/](\d{4})$/.exec(date);
    if (matches == null) return false;
    var d = matches[1];
    var m = matches[2]-1;
    var y = matches[3];
    var composedDate = new Date(y, m, d);
    return composedDate.getDate() == d &&
           composedDate.getMonth() == m &&
           composedDate.getFullYear() == y;
}
console.log(isValidDate('10-12-1961'));
console.log(isValidDate('12/11/1961'));
console.log(isValidDate('02-11-1961'));
console.log(isValidDate('12/01/1961'));
console.log(isValidDate('13-11-1961'));
console.log(isValidDate('11-31-1961'));
console.log(isValidDate('11-31-1061'));

How do you get AngularJS to bind to the title attribute of an A tag?

It looks like ng-attr is a new directive in AngularJS 1.1.4 that you can possibly use in this case.

<!-- example -->
<a ng-attr-title="{{product.shortDesc}}"></a>

However, if you stay with 1.0.7, you can probably write a custom directive to mirror the effect.

Write lines of text to a file in R

I would use the cat() command as in this example:

> cat("Hello",file="outfile.txt",sep="\n")
> cat("World",file="outfile.txt",append=TRUE)

You can then view the results from with R with

> file.show("outfile.txt")
hello
world