Programs & Examples On #Account

Account allows a user to authenticate (does not imply authorization) to system services and be granted authorization to access them;. To log into an account, a user is typically required to authenticate oneself with a password or other credentials for the purposes of accounting, security, logging, and resource management.

How to transfer paid android apps from one google account to another google account

Google has this to say on transferring data between accounts.

http://support.google.com/accounts/bin/answer.py?hl=en&answer=63304

It lists certain types of data that CAN be transferred and certain types of data that CAN NOT be transferred. Unfortunately Google Play Apps falls into the NOT category.

It's conveniently titled: "Moving Product Data"

http://support.google.com/accounts/bin/answer.py?hl=en&answer=58582

Multiple conditions in if statement shell script

You are trying to compare strings inside an arithmetic command (((...))). Use [[ instead.

if [[ $username == "$username1" && $password == "$password1" ]] ||
   [[ $username == "$username2" && $password == "$password2" ]]; then

Note that I've reduced this to two separate tests joined by ||, with the && moved inside the tests. This is because the shell operators && and || have equal precedence and are simply evaluated from left to right. As a result, it's not generally true that a && b || c && d is equivalent to the intended ( a && b ) || ( c && d ).

How to Validate on Max File Size in Laravel?

Edit: Warning! This answer worked on my XAMPP OsX environment, but when I deployed it to AWS EC2 it did NOT prevent the upload attempt.

I was tempted to delete this answer as it is WRONG But instead I will explain what tripped me up

My file upload field is named 'upload' so I was getting "The upload failed to upload.". This message comes from this line in validation.php:

in resources/lang/en/validaton.php:

'uploaded' => 'The :attribute failed to upload.',

And this is the message displayed when the file is larger than the limit set by PHP.

I want to over-ride this message, which you normally can do by passing a third parameter $messages array to Validator::make() method.

However I can't do that as I am calling the POST from a React Component, which renders the form containing the csrf field and the upload field.

So instead, as a super-dodgy-hack, I chose to get into my view that displays the messages and replace that specific message with my friendly 'file too large' message.

Here is what works if the file to smaller than the PHP file size limit:

In case anyone else is using Laravel FormRequest class, here is what worked for me on Laravel 5.7:

This is how I set a custom error message and maximum file size:

I have an input field <input type="file" name="upload">. Note the CSRF token is required also in the form (google laravel csrf_field for what this means).

<?php
namespace App\Http\Requests;
use Illuminate\Foundation\Http\FormRequest;
class Upload extends FormRequest
{
  ...
  ...
  public function rules() {
    return [
      'upload' => 'required|file|max:8192',
    ];
  }
  public function messages()
  {
    return [            
      'upload.required' => "You must use the 'Choose file' button to select which file you wish to upload",
      'upload.max' => "Maximum file size to upload is 8MB (8192 KB). If you are uploading a photo, try to reduce its resolution to make it under 8MB"
    ];
  }
}

How to kill a child process by the parent process?

In the parent process, fork()'s return value is the process ID of the child process. Stuff that value away somewhere for when you need to terminate the child process. fork() returns zero(0) in the child process.

When you need to terminate the child process, use the kill(2) function with the process ID returned by fork(), and the signal you wish to deliver (e.g. SIGTERM).

Remember to call wait() on the child process to prevent any lingering zombies.

How can I run a PHP script inside a HTML file?

You can't run PHP in an html page ending with .html. Unless the page is actually PHP and the extension was changed with .htaccess from .php to .html

What you mean is:

index.html
<html>
...
<?php echo "Hello world";?> //This is impossible


index.php //The file extension can be changed using htaccess, ex: its type stays php but will be visible to visitors as index.html

<?php echo "Hello world";?>

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

$content = '';
    for($rowth=0; $rowth<=100; $rowth++){
        $content .= $selenium->getTable("tblReports.{$rowth}.0") . "\n";
        //$content .= $selenium->getTable("tblReports.{$rowth}.1") . "\n";
        $content .= $selenium->getTable("tblReports.{$rowth}.2") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.3") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.4") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.5") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.6") . "\n";

    }

Custom Python list sorting

Just like this example. You want sort this list.

[('c', 2), ('b', 2), ('a', 3)]

output:

[('a', 3), ('b', 2), ('c', 2)]

you should sort the tuples by the second item, then the first:

def letter_cmp(a, b):
    if a[1] > b[1]:
        return -1
    elif a[1] == b[1]:
        if a[0] > b[0]:
            return 1
        else:
            return -1
    else:
        return 1

Then convert it to a key function:

from functools import cmp_to_key
letter_cmp_key = cmp_to_key(letter_cmp))

Now you can use your custom sort order:

[('c', 2), ('b', 2), ('a', 3)].sort(key=letter_cmp_key)

remove legend title in ggplot

You were almost there : just add theme(legend.title=element_blank())

ggplot(df, aes(x, y, colour=g)) +
  geom_line(stat="identity") + 
  theme(legend.position="bottom") +
  theme(legend.title=element_blank())

This page on Cookbook for R gives plenty of details on how to customize legends.

Is there a C# String.Format() equivalent in JavaScript?

I created it a long time ago, related question

String.Format = function (b) {
    var a = arguments;
    return b.replace(/(\{\{\d\}\}|\{\d\})/g, function (b) {
        if (b.substring(0, 2) == "{{") return b;
        var c = parseInt(b.match(/\d/)[0]);
        return a[c + 1]
    })
};

How can I login to a website with Python?

Web page automation ? Definitely "webbot"

webbot even works web pages which have dynamically changing id and classnames and has more methods and features than selenium or mechanize.

Here's a snippet :)

from webbot import Browser 
web = Browser()
web.go_to('google.com') 
web.click('Sign in')
web.type('[email protected]' , into='Email')
web.click('NEXT' , tag='span')
web.type('mypassword' , into='Password' , id='passwordFieldId') # specific selection
web.click('NEXT' , tag='span') # you are logged in ^_^

The docs are also pretty straight forward and simple to use : https://webbot.readthedocs.io

ORA-01882: timezone region not found

This issue happens as the code which is trying to connect to db, has a timezone which is not in db. It can also be resolved by setting the time zone as below or any valid time zone available in oracle db. valid time zone which can be found select * from v$version;

System.setProperty("user.timezone", "America/New_York"); TimeZone.setDefault(null);

Linking dll in Visual Studio

On Windows you do not link with a .dll file directly – you must use the accompanying .lib file instead. To do that go to Project -> Properties -> Configuration Properties -> Linker -> Additional Dependencies and add path to your .lib as a next line.

You also must make sure that the .dll file is either in the directory contained by the %PATH% environment variable or that its copy is in Output Directory (by default, this is Debug\Release under your project's folder).

If you don't have access to the .lib file, one alternative is to load the .dll manually during runtime using WINAPI functions such as LoadLibrary and GetProcAddress.

Rewrite URL after redirecting 404 error htaccess

Try adding this rule to the top of your htaccess:

RewriteEngine On
RewriteRule ^404/?$ /pages/errors/404.php [L]

Then under that (or any other rules that you have):

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-l
RewriteRule ^ http://domain.com/404/ [L,R]

PHP, get file name without file extension

@Gordon basename will work fine if you know the extension, if you dont you can use explode:

$filename = end(explode(".", $file));

How is Perl's @INC constructed? (aka What are all the ways of affecting where Perl modules are searched for?)

We will look at how the contents of this array are constructed and can be manipulated to affect where the Perl interpreter will find the module files.

  1. Default @INC

    Perl interpreter is compiled with a specific @INC default value. To find out this value, run env -i perl -V command (env -i ignores the PERL5LIB environmental variable - see #2) and in the output you will see something like this:

    $ env -i perl -V
    ...
    @INC:
     /usr/lib/perl5/site_perl/5.18.0/x86_64-linux-thread-multi-ld
     /usr/lib/perl5/site_perl/5.18.0
     /usr/lib/perl5/5.18.0/x86_64-linux-thread-multi-ld
     /usr/lib/perl5/5.18.0
     .
    

Note . at the end; this is the current directory (which is not necessarily the same as the script's directory). It is missing in Perl 5.26+, and when Perl runs with -T (taint checks enabled).

To change the default path when configuring Perl binary compilation, set the configuration option otherlibdirs:

Configure -Dotherlibdirs=/usr/lib/perl5/site_perl/5.16.3

  1. Environmental variable PERL5LIB (or PERLLIB)

    Perl pre-pends @INC with a list of directories (colon-separated) contained in PERL5LIB (if it is not defined, PERLLIB is used) environment variable of your shell. To see the contents of @INC after PERL5LIB and PERLLIB environment variables have taken effect, run perl -V.

    $ perl -V
    ...
    %ENV:
      PERL5LIB="/home/myuser/test"
    @INC:
     /home/myuser/test
     /usr/lib/perl5/site_perl/5.18.0/x86_64-linux-thread-multi-ld
     /usr/lib/perl5/site_perl/5.18.0
     /usr/lib/perl5/5.18.0/x86_64-linux-thread-multi-ld
     /usr/lib/perl5/5.18.0
     .
    
  2. -I command-line option

    Perl pre-pends @INC with a list of directories (colon-separated) passed as value of the -I command-line option. This can be done in three ways, as usual with Perl options:

    • Pass it on command line:

      perl -I /my/moduledir your_script.pl
      
    • Pass it via the first line (shebang) of your Perl script:

      #!/usr/local/bin/perl -w -I /my/moduledir
      
    • Pass it as part of PERL5OPT (or PERLOPT) environment variable (see chapter 19.02 in Programming Perl)

  3. Pass it via the lib pragma

    Perl pre-pends @INC with a list of directories passed in to it via use lib.

    In a program:

    use lib ("/dir1", "/dir2");
    

    On the command line:

    perl -Mlib=/dir1,/dir2
    

    You can also remove the directories from @INC via no lib.

  4. You can directly manipulate @INC as a regular Perl array.

    Note: Since @INC is used during the compilation phase, this must be done inside of a BEGIN {} block, which precedes the use MyModule statement.

    • Add directories to the beginning via unshift @INC, $dir.

    • Add directories to the end via push @INC, $dir.

    • Do anything else you can do with a Perl array.

Note: The directories are unshifted onto @INC in the order listed in this answer, e.g. default @INC is last in the list, preceded by PERL5LIB, preceded by -I, preceded by use lib and direct @INC manipulation, the latter two mixed in whichever order they are in Perl code.

References:

There does not seem to be a comprehensive @INC FAQ-type post on Stack Overflow, so this question is intended as one.

When to use each approach?

  • If the modules in a directory need to be used by many/all scripts on your site, especially run by multiple users, that directory should be included in the default @INC compiled into the Perl binary.

  • If the modules in the directory will be used exclusively by a specific user for all the scripts that user runs (or if recompiling Perl is not an option to change default @INC in previous use case), set the users' PERL5LIB, usually during user login.

    Note: Please be aware of the usual Unix environment variable pitfalls - e.g. in certain cases running the scripts as a particular user does not guarantee running them with that user's environment set up, e.g. via su.

  • If the modules in the directory need to be used only in specific circumstances (e.g. when the script(s) is executed in development/debug mode, you can either set PERL5LIB manually, or pass the -I option to perl.

  • If the modules need to be used only for specific scripts, by all users using them, use use lib/no lib pragmas in the program itself. It also should be used when the directory to be searched needs to be dynamically determined during runtime - e.g. from the script's command line parameters or script's path (see the FindBin module for very nice use case).

  • If the directories in @INC need to be manipulated according to some complicated logic, either impossible to too unwieldy to implement by combination of use lib/no lib pragmas, then use direct @INC manipulation inside BEGIN {} block or inside a special purpose library designated for @INC manipulation, which must be used by your script(s) before any other modules are used.

    An example of this is automatically switching between libraries in prod/uat/dev directories, with waterfall library pickup in prod if it's missing from dev and/or UAT (the last condition makes the standard "use lib + FindBin" solution fairly complicated. A detailed illustration of this scenario is in How do I use beta Perl modules from beta Perl scripts?.

  • An additional use case for directly manipulating @INC is to be able to add subroutine references or object references (yes, Virginia, @INC can contain custom Perl code and not just directory names, as explained in When is a subroutine reference in @INC called?).

Select Multiple Fields from List in Linq

var selectedCategories =
    from value in
        (from data in listObject
        orderby data.category_name descending
        select new { ID = data.category_id, Name = data.category_name })
    group value by value.Name into g
    select g.First();

foreach (var category in selectedCategories) Console.WriteLine(category);

Edit: Made it more LINQ-ey!

Angularjs checkbox checked by default on load and disables Select list when checked

Do it in the controller

_x000D_
_x000D_
$timeout(function(){
$scope.checked = true;
}, 1);
_x000D_
_x000D_
_x000D_

then remove ng-checked.

Search in lists of lists by given index

Nothing wrong with using a gen exp, but if the goal is to inline the loop...

>>> import itertools, operator
>>> 'b' in itertools.imap(operator.itemgetter(1), the_list)
True

Should be the fastest as well.

How to access remote server with local phpMyAdmin client?

It can be done, but you need to change the phpMyAdmin configuration, read this post: http://www.danielmois.com/article/Manage_remote_databases_from_localhost_with_phpMyAdmin

If for any reason the link dies, you can use the following steps:

  • Find phpMyAdmin's configuration file, called config.inc.php
  • Find the $cfg['Servers'][$i]['host'] variable, and set it to the IP or hostname of your remote server
  • Find the $cfg['Servers'][$i]['port'] variable, and set it to the remote mysql port. Usually this is 3306
  • Find the $cfg['Servers'][$i]['user'] and $cfg['Servers'][$i]['password'] variables and set these to your username and password for the remote server

Without proper server configuration, the connection may be slower than a local connection for example, it's would probably be slightly faster to use IP addresses instead of host names to avoid the server having to look up the IP address from the hostname.

In addition, remember that your remote database's username and password is stored in plain text when you connect like this, so you should take steps to ensure that no one can access this config file. Alternatively, you can leave the username and password variables empty to be prompted to enter them each time you log in, which is a lot more secure.

Negative weights using Dijkstra's Algorithm

You can use dijkstra's algorithm with negative edges not including negative cycle, but you must allow a vertex can be visited multiple times and that version will lose it's fast time complexity.

In that case practically I've seen it's better to use SPFA algorithm which have normal queue and can handle negative edges.

How to change a Git remote on Heroku

Assuming your current remote is named origin then:

Delete the current remote reference with

git remote rm origin

Add the new remote

git remote add origin <URL to new heroku app>

push to new domain

git push -u origin master

The -u will set this up as tracked.

Bootstrap carousel width and height

I had the same problem.

My height changed to its original height while my slide was animating to the left, ( in a responsive website )

so I fixed it with CSS only :

.carousel .item.left img{
    width: 100% !important;
}

Relative imports - ModuleNotFoundError: No module named x

If you are using python 3+ then try adding below lines

import os, sys
dir_path = os.path.dirname(os.path.realpath(__file__))
parent_dir_path = os.path.abspath(os.path.join(dir_path, os.pardir))
sys.path.insert(0, parent_dir_path)

How do I decrease the size of my sql server log file?

  1. Ensure the database's backup mode is set to Simple (see here for an overview of the different modes). This will avoid SQL Server waiting for a transaction log backup before reusing space.

  2. Use dbcc shrinkfile or Management Studio to shrink the log files.

Step #2 will do nothing until the backup mode is set.

How do I set the background color of Excel cells using VBA?

Do a quick 'record macro' to see the color number associated with the color you're looking for (yellow highlight is 65535). Then erase the code and put

Sub Name()
Selection.Interior.Color = 65535 '(your number may be different depending on the above)
End Sub

Typescript Date Type?

Every class or interface can be used as a type in TypeScript.

 const date = new Date();

will already know about the date type definition as Date is an internal TypeScript object referenced by the DateConstructor interface.

And for the constructor you used, it is defined as:

interface DateConstructor {
    new(): Date;
    ...
}

To make it more explicit, you can use:

 const date: Date = new Date();

You might be missing the type definitions though, the Date is coming for my example from the ES6 lib, and in my tsconfig.json I have defined:

"compilerOptions": {
    "target": "ES6",
    "lib": [
        "es6",
        "dom"
    ],

You might adapt these settings to target your wanted version of JavaScript.


The Date is by the way an Interface from lib.es6.d.ts:

/** Enables basic storage and retrieval of dates and times. */
interface Date {
    /** Returns a string representation of a date. The format of the string depends on the locale. */
    toString(): string;
    /** Returns a date as a string value. */
    toDateString(): string;
    /** Returns a time as a string value. */
    toTimeString(): string;
    /** Returns a value as a string value appropriate to the host environment's current locale. */
    toLocaleString(): string;
    /** Returns a date as a string value appropriate to the host environment's current locale. */
    toLocaleDateString(): string;
    /** Returns a time as a string value appropriate to the host environment's current locale. */
    toLocaleTimeString(): string;
    /** Returns the stored time value in milliseconds since midnight, January 1, 1970 UTC. */
    valueOf(): number;
    /** Gets the time value in milliseconds. */
    getTime(): number;
    /** Gets the year, using local time. */
    getFullYear(): number;
    /** Gets the year using Universal Coordinated Time (UTC). */
    getUTCFullYear(): number;
    /** Gets the month, using local time. */
    getMonth(): number;
    /** Gets the month of a Date object using Universal Coordinated Time (UTC). */
    getUTCMonth(): number;
    /** Gets the day-of-the-month, using local time. */
    getDate(): number;
    /** Gets the day-of-the-month, using Universal Coordinated Time (UTC). */
    getUTCDate(): number;
    /** Gets the day of the week, using local time. */
    getDay(): number;
    /** Gets the day of the week using Universal Coordinated Time (UTC). */
    getUTCDay(): number;
    /** Gets the hours in a date, using local time. */
    getHours(): number;
    /** Gets the hours value in a Date object using Universal Coordinated Time (UTC). */
    getUTCHours(): number;
    /** Gets the minutes of a Date object, using local time. */
    getMinutes(): number;
    /** Gets the minutes of a Date object using Universal Coordinated Time (UTC). */
    getUTCMinutes(): number;
    /** Gets the seconds of a Date object, using local time. */
    getSeconds(): number;
    /** Gets the seconds of a Date object using Universal Coordinated Time (UTC). */
    getUTCSeconds(): number;
    /** Gets the milliseconds of a Date, using local time. */
    getMilliseconds(): number;
    /** Gets the milliseconds of a Date object using Universal Coordinated Time (UTC). */
    getUTCMilliseconds(): number;
    /** Gets the difference in minutes between the time on the local computer and Universal Coordinated Time (UTC). */
    getTimezoneOffset(): number;
    /**
      * Sets the date and time value in the Date object.
      * @param time A numeric value representing the number of elapsed milliseconds since midnight, January 1, 1970 GMT.
      */
    setTime(time: number): number;
    /**
      * Sets the milliseconds value in the Date object using local time.
      * @param ms A numeric value equal to the millisecond value.
      */
    setMilliseconds(ms: number): number;
    /**
      * Sets the milliseconds value in the Date object using Universal Coordinated Time (UTC).
      * @param ms A numeric value equal to the millisecond value.
      */
    setUTCMilliseconds(ms: number): number;

    /**
      * Sets the seconds value in the Date object using local time.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setSeconds(sec: number, ms?: number): number;
    /**
      * Sets the seconds value in the Date object using Universal Coordinated Time (UTC).
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setUTCSeconds(sec: number, ms?: number): number;
    /**
      * Sets the minutes value in the Date object using local time.
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setMinutes(min: number, sec?: number, ms?: number): number;
    /**
      * Sets the minutes value in the Date object using Universal Coordinated Time (UTC).
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setUTCMinutes(min: number, sec?: number, ms?: number): number;
    /**
      * Sets the hour value in the Date object using local time.
      * @param hours A numeric value equal to the hours value.
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setHours(hours: number, min?: number, sec?: number, ms?: number): number;
    /**
      * Sets the hours value in the Date object using Universal Coordinated Time (UTC).
      * @param hours A numeric value equal to the hours value.
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setUTCHours(hours: number, min?: number, sec?: number, ms?: number): number;
    /**
      * Sets the numeric day-of-the-month value of the Date object using local time.
      * @param date A numeric value equal to the day of the month.
      */
    setDate(date: number): number;
    /**
      * Sets the numeric day of the month in the Date object using Universal Coordinated Time (UTC).
      * @param date A numeric value equal to the day of the month.
      */
    setUTCDate(date: number): number;
    /**
      * Sets the month value in the Date object using local time.
      * @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively.
      * @param date A numeric value representing the day of the month. If this value is not supplied, the value from a call to the getDate method is used.
      */
    setMonth(month: number, date?: number): number;
    /**
      * Sets the month value in the Date object using Universal Coordinated Time (UTC).
      * @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively.
      * @param date A numeric value representing the day of the month. If it is not supplied, the value from a call to the getUTCDate method is used.
      */
    setUTCMonth(month: number, date?: number): number;
    /**
      * Sets the year of the Date object using local time.
      * @param year A numeric value for the year.
      * @param month A zero-based numeric value for the month (0 for January, 11 for December). Must be specified if numDate is specified.
      * @param date A numeric value equal for the day of the month.
      */
    setFullYear(year: number, month?: number, date?: number): number;
    /**
      * Sets the year value in the Date object using Universal Coordinated Time (UTC).
      * @param year A numeric value equal to the year.
      * @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively. Must be supplied if numDate is supplied.
      * @param date A numeric value equal to the day of the month.
      */
    setUTCFullYear(year: number, month?: number, date?: number): number;
    /** Returns a date converted to a string using Universal Coordinated Time (UTC). */
    toUTCString(): string;
    /** Returns a date as a string value in ISO format. */
    toISOString(): string;
    /** Used by the JSON.stringify method to enable the transformation of an object's data for JavaScript Object Notation (JSON) serialization. */
    toJSON(key?: any): string;
}

How to set max and min value for Y axis

There's so many conflicting answers to this, most of which had no effect for me.

I was finally able to set (or retrieve current) X-axis minimum & maximum displayed values with chart.options.scales.xAxes[0].ticks.min (even if min & max are only a subset of the data assigned to the chart.)

Using a time scale in my case, I used:

chart.options.scales.xAxes[0].ticks.min = 1590969600000;  //Jun 1, 2020
chart.options.scales.xAxes[0].ticks.max = 1593561600000;  //Jul 1, 2020
chart.update();

(I found no need to set the step values or beginAtZero, etc.)

how to get multiple checkbox value using jquery

You can do it like this,

$('.ads_Checkbox:checked')

You can iterate through them with each() and fill the array with checkedbox values.

Live Demo

To get the values of selected checkboxes in array

var i = 0;
$('#save_value').click(function () {
       var arr = [];
       $('.ads_Checkbox:checked').each(function () {
           arr[i++] = $(this).val();
       });      
});

Edit, using .map()

You can also use jQuery.map with get() to get the array of selected checkboxe values.

As a side note using this.value instead of $(this).val() would give better performance.

Live Demo

$('#save_value').click(function(){
    var arr = $('.ads_Checkbox:checked').map(function(){
        return this.value;
    }).get();
}); 

How to check the differences between local and github before the pull

And another useful command to do this (after git fetch) is:

git log origin/master ^master

This shows the commits that are in origin/master but not in master. You can also do it in opposite when doing git pull, to check what commits will be submitted to remote.

Installing Java 7 on Ubuntu

Oracle Java 1.7.0 from .deb packages

wget https://raw.github.com/flexiondotorg/oab-java6/master/oab-java.sh
chmod +x oab-java.sh
sudo ./oab-java.sh -7
sudo apt-get update
sudo sudo apt-get install oracle-java7-jdk oracle-java7-fonts oracle-java7-source 
sudo apt-get dist-upgrade

Workaround for 1.7.0_51

There is an Issue 123 currently in OAB and a pull request

Here is the patched vesion:

wget https://raw.github.com/ladios/oab-java6/master/oab-java.sh
chmod +x oab-java.sh
sudo ./oab-java.sh -7
sudo apt-get update
sudo sudo apt-get install oracle-java7-jdk oracle-java7-fonts oracle-java7-source 
sudo apt-get dist-upgrade

Android emulator shows nothing except black screen and adb devices shows "device offline"

Make sure that you've installed the latest HAXM revision. I had the same blank screen problem with version 1.0.1 while 1.0.8 was already available. The installer can be downloaded via the SDK tools, to actually install the module you would have to execute

android-sdk-directory\extras\intel\Hardware_Accelerated_Execution_Manager\intelhaxm.exe

Iterate Multi-Dimensional Array with Nested Foreach Statement

I was looking for a solution to enumerate an array of an unknown at compile time rank with an access to every element indices set. I saw solutions with yield but here is another implementation with no yield. It is in old school minimalistic way. In this example AppendArrayDebug() just prints all the elements into StringBuilder buffer.

public static void AppendArrayDebug ( StringBuilder sb, Array array )
{
    if( array == null || array.Length == 0 )
    {
        sb.Append( "<nothing>" );
        return;
    }

    int i;

    var rank = array.Rank;
    var lastIndex = rank - 1;

    // Initialize indices and their boundaries
    var indices = new int[rank];
    var lower = new int[rank];
    var upper = new int[rank];
    for( i = 0; i < rank; ++i )
    {
        indices[i] = lower[i] = array.GetLowerBound( i );
        upper[i] = array.GetUpperBound( i );
    }

    while( true )
    {
        BeginMainLoop:

        // Begin work with an element

        var element = array.GetValue( indices );

        sb.AppendLine();
        sb.Append( '[' );
        for( i = 0; i < rank; ++i )
        {
            sb.Append( indices[i] );
            sb.Append( ' ' );
        }
        sb.Length -= 1;
        sb.Append( "] = " );
        sb.Append( element );

        // End work with the element

        // Increment index set

        // All indices except the first one are enumerated several times
        for( i = lastIndex; i > 0; )
        {
            if( ++indices[i] <= upper[i] )
                goto BeginMainLoop;
            indices[i] = lower[i];
            --i;
        }

        // Special case for the first index, it must be enumerated only once
        if( ++indices[0] > upper[0] )
            break;
    }
}

For example the following array will produce the following output:

var array = new [,,]
{
    { {  1,  2,  3 }, {  4,  5,  6 }, {  7,  8,  9 }, { 10, 11, 12 } },
    { { 13, 14, 15 }, { 16, 17, 18 }, { 19, 20, 21 }, { 22, 23, 24 } }
};

/*
Output:

[0 0 0] = 1
[0 0 1] = 2
[0 0 2] = 3
[0 1 0] = 4
[0 1 1] = 5
[0 1 2] = 6
[0 2 0] = 7
[0 2 1] = 8
[0 2 2] = 9
[0 3 0] = 10
[0 3 1] = 11
[0 3 2] = 12
[1 0 0] = 13
[1 0 1] = 14
[1 0 2] = 15
[1 1 0] = 16
[1 1 1] = 17
[1 1 2] = 18
[1 2 0] = 19
[1 2 1] = 20
[1 2 2] = 21
[1 3 0] = 22
[1 3 1] = 23
[1 3 2] = 24
*/

How to run Spyder in virtual environment?

Here is a quick way to do it in 2021 using the Anaconda Navigator. This is the most reliable way to do it, unless you want to create environments programmatically which I don't think is the case for most users:

  1. Open Anaconda Navigator.
  2. Click on Environments > Create and give a name to your environment. Be sure to change Python/R Kernel version if needed.

enter image description here

  1. Go "Home" and click on "Install" under the Spyder box.

enter image description here

  1. Click "Launch/Run"

There are still a few minor bugs when setting up your environment, most of them should be solved by restarting the Navigator.

If you find a bug, please help us posting it in the Anaconda Issues bug-tracker too! If you run into trouble creating the environment or if the environment was not correctly created you can double check what got installed: Clicking the "Environments" opens a management window showing installed packages. Search and select Spyder-related packages and then click on "Apply" to install them.

enter image description here

How can I INSERT data into two tables simultaneously in SQL Server?

Another option is to run the two inserts separately, leaving the FK column null, then running an update to poulate it correctly.

If there is nothing natural stored within the two tables that match from one record to another (likely) then create a temporary GUID column and populate this in your data and insert to both fields. Then you can update with the proper FK and null out the GUIDs.

E.g.:

CREATE TABLE [dbo].[table1] ( 
    [id] [int] IDENTITY(1,1) NOT NULL, 
    [data] [varchar](255) NOT NULL, 
    CONSTRAINT [PK_table1] PRIMARY KEY CLUSTERED ([id] ASC),
    JoinGuid UniqueIdentifier NULL
) 

CREATE TABLE [dbo].[table2] ( 
    [id] [int] IDENTITY(1,1) NOT NULL, 
    [table1_id] [int] NULL, 
    [data] [varchar](255) NOT NULL, 
    CONSTRAINT [PK_table2] PRIMARY KEY CLUSTERED ([id] ASC),
    JoinGuid UniqueIdentifier NULL
) 


INSERT INTO Table1....

INSERT INTO Table2....

UPDATE b
SET table1_id = a.id
FROM Table1 a
JOIN Table2 b on a.JoinGuid = b.JoinGuid
WHERE b.table1_id IS NULL

UPDATE Table1 SET JoinGuid = NULL
UPDATE Table2 SET JoinGuid = NULL

How to delete a specific file from folder using asp.net

Check the GridView1.SelectedRow is not null:

if (GridView1.SelectedRow == null) return;
string DeleteThis = GridView1.SelectedRow.Cells[0].Text;

How to check if character is a letter in Javascript?

It's possible to know if the character is a letter or not by using a standard builtin function isNaN or Number.isNaN() from ES6:

isNaN('s') // true
isNaN('-') // true
isNaN('32') // false, '32' is converted to the number 32 which is not NaN

It retruns true if the given value is not a number, otherwise false.

How can I add an item to a ListBox in C# and WinForms?

ListBoxItem is a WPF class, NOT a WinForms class.

For WPF, use ListBoxItem.

For WinForms, the item is a Object type, so use one of these:
1. Provide your own ToString() method for the Object type.
2. Use databinding with DisplayMemeber and ValueMember (see Kelsey's answer)

How to display an image from a path in asp.net MVC 4 and Razor view?

In your View try like this

  <img src= "@Url.Content(Model.ImagePath)" alt="Image" />

jQuery jump or scroll to certain position, div or target on the page from button onclick

$("html, body").scrollTop($(element).offset().top); // <-- Also integer can be used

excel delete row if column contains value from to-remove-list

Given sheet 2:

ColumnA
-------
apple
orange

You can flag the rows in sheet 1 where a value exists in sheet 2:

ColumnA  ColumnB
-------  --------------
pear     =IF(ISERROR(VLOOKUP(A1,Sheet2!A:A,1,FALSE)),"Keep","Delete")
apple    =IF(ISERROR(VLOOKUP(A2,Sheet2!A:A,1,FALSE)),"Keep","Delete")
cherry   =IF(ISERROR(VLOOKUP(A3,Sheet2!A:A,1,FALSE)),"Keep","Delete")
orange   =IF(ISERROR(VLOOKUP(A4,Sheet2!A:A,1,FALSE)),"Keep","Delete")
plum     =IF(ISERROR(VLOOKUP(A5,Sheet2!A:A,1,FALSE)),"Keep","Delete")

The resulting data looks like this:

ColumnA  ColumnB
-------  --------------
pear     Keep
apple    Delete
cherry   Keep
orange   Delete
plum     Keep

You can then easily filter or sort sheet 1 and delete the rows flagged with 'Delete'.

Export Postgresql table data using pgAdmin

Just right click on a table and select "backup". The popup will show various options, including "Format", select "plain" and you get plain SQL.

pgAdmin is just using pg_dump to create the dump, also when you want plain SQL.

It uses something like this:

pg_dump --user user --password --format=plain --table=tablename --inserts --attribute-inserts etc.

JIRA JQL searching by date - is there a way of getting Today() (Date) instead of Now() (DateTime)

You would expect that this is easily possible but that seems not be the case. The only way I see at the moment is to create a user defined JQL function. I never tried this but here is a plug-in:

http://confluence.atlassian.com/display/DEVNET/Plugin+Tutorial+-+Adding+a+JQL+Function+to+JIRA

Min/Max of dates in an array?

**Use Spread Operators| ES6 **

let datesVar = [ 2017-10-26T03:37:10.876Z,
  2017-10-27T03:37:10.876Z,
  2017-10-23T03:37:10.876Z,
  2015-10-23T03:37:10.876Z ]

Math.min(...datesVar);

That will give the minimum date from the array.

Its shorthand Math.min.apply(null, ArrayOfdates);

Break statement in javascript array map method

That's not possible using the built-in Array.prototype.map. However, you could use a simple for-loop instead, if you do not intend to map any values:

var hasValueLessThanTen = false;
for (var i = 0; i < myArray.length; i++) {
  if (myArray[i] < 10) {
    hasValueLessThanTen = true;
    break;
  }
}

Or, as suggested by @RobW, use Array.prototype.some to test if there exists at least one element that is less than 10. It will stop looping when some element that matches your function is found:

var hasValueLessThanTen = myArray.some(function (val) { 
  return val < 10;
});

Getting Integer value from a String using javascript/jquery

just do this , you need to remove char other than "numeric" and "." form your string will do work for you

yourString = yourString.replace ( /[^\d.]/g, '' );

your final code will be

  str1 = "test123.00".replace ( /[^\d.]/g, '' );
  str2 = "yes50.00".replace ( /[^\d.]/g, '' );
  total = parseInt(str1, 10) + parseInt(str2, 10);
  alert(total);

Demo

React "after render" code?

One drawback of using componentDidUpdate, or componentDidMount is that they are actually executed before the dom elements are done being drawn, but after they've been passed from React to the browser's DOM.

Say for example if you needed set node.scrollHeight to the rendered node.scrollTop, then React's DOM elements may not be enough. You need to wait until the elements are done being painted to get their height.

Solution:

Use requestAnimationFrame to ensure that your code is run after the painting of your newly rendered object

scrollElement: function() {
  // Store a 'this' ref, and
  var _this = this;
  // wait for a paint before running scrollHeight dependent code.
  window.requestAnimationFrame(function() {
    var node = _this.getDOMNode();
    if (node !== undefined) {
      node.scrollTop = node.scrollHeight;
    }
  });
},
componentDidMount: function() {
  this.scrollElement();
},
// and or
componentDidUpdate: function() {
  this.scrollElement();
},
// and or
render: function() {
  this.scrollElement()
  return [...]

How do I select an entire row which has the largest ID in the table?

You could use a subselect:

SELECT row 
FROM table 
WHERE id=(
    SELECT max(id) FROM table
    )

Note that if the value of max(id) is not unique, multiple rows are returned.

If you only want one such row, use @MichaelMior's answer,

SELECT row from table ORDER BY id DESC LIMIT 1

How do you import classes in JSP?

In the page tag:

<%@ page import="java.util.List" %>

Simulating group_concat MySQL function in Microsoft SQL Server 2005?

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

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

How to convert existing non-empty directory into a Git working directory and push files to a remote repository

Here's my solution:

git init
git remote add origin PATH/TO/REPO
git fetch
git checkout -t origin/master

Add shadow to custom shape on Android

After Lots of search finally I got this

enter image description here

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<!-- Bottom 2dp Shadow -->
<item>
    <shape  android:shape="rectangle">

        <solid android:color="#d8d8d8" />
        <corners android:radius="7dp" />

    </shape>
</item>

<!-- White Top color -->
<item android:bottom="3px">

    <shape  android:shape="rectangle">

    <solid android:color="#FFFFFF" />
    <corners android:radius="7dp" />


    </shape>

</item>


</layer-list>

SQL alias for SELECT statement

You can do this using the WITH clause of the SELECT statement:

;
WITH my_select As (SELECT ... FROM ...) 
SELECT * FROM foo
WHERE id IN (SELECT MAX(id) FROM my_select GROUP BY name)

That's the ANSI/ISO SQL Syntax. I know that SQL Server, Oracle and DB2 support it. Not sure about the others...

How to know function return type and argument types?

I attended a coursera course, there was lesson in which, we were taught about design recipe.

Below docstring format I found preety useful.

def area(base, height):
    '''(number, number ) -> number    #**TypeContract**
    Return the area of a tring with dimensions base   #**Description**
    and height

    >>>area(10,5)          #**Example **
    25.0
    >>area(2.5,3)
    3.75
    '''
    return (base * height) /2 

I think if docstrings are written in this way, it might help a lot to developers.

Link to video [Do watch the video] : https://www.youtube.com/watch?v=QAPg6Vb_LgI

React component not re-rendering on state change

After looking into many answers (most of them are correct for their scenarios) and none of them fix my problem I realized that my case is a bit different:

In my weird scenario my component was being rendered inside the state and therefore couldn't be updated. Below is a simple example:

constructor() {
    this.myMethod = this.myMethod.bind(this);
    this.changeTitle = this.changeTitle.bind(this);

    this.myMethod();
}

changeTitle() {
    this.setState({title: 'I will never get updated!!'});
}

myMethod() {
    this.setState({body: <div>{this.state.title}</div>});
}

render() {
    return <>
        {this.state.body}
        <Button onclick={() => this.changeTitle()}>Change Title!</Button>
    </>
}

After refactoring the code to not render the body from state it worked fine :)

SQL Server format decimal places with commas

without considering this to be a good idea...

select dbo.F_AddThousandSeparators(convert(varchar, convert(decimal(18, 4), 1234.1234567), 1))

Function

-- Author:      bummi
-- Create date: 20121106
CREATE FUNCTION F_AddThousandSeparators(@NumStr varchar(50)) 
RETURNS Varchar(50)
AS
BEGIN
declare @OutStr varchar(50)
declare @i int
declare @run int

Select @i=CHARINDEX('.',@NumStr)
if @i=0 
    begin
    set @i=LEN(@NumStr)
    Set @Outstr=''
    end
else
    begin   
     Set @Outstr=SUBSTRING(@NUmStr,@i,50)
     Set @i=@i -1
    end 


Set @run=0

While @i>0
    begin
      if @Run=3
        begin
          Set @Outstr=','+@Outstr
          Set @run=0
        end
      Set @Outstr=SUBSTRING(@NumStr,@i,1) +@Outstr  
      Set @i=@i-1
      Set @run=@run + 1     
    end

    RETURN @OutStr

END
GO

curl.h no such file or directory

To those who use centos and have stumbled upon this post :

 $ yum install curl-devel

and when compiling your program example.cpp, link to the curl library:

 $ g++ example.cpp -lcurl -o example

"-o example" creates the executable example instead of the default a.out.

The next line runs example:

 $ ./example

using OR and NOT in solr query

Putting together comments from a couple different answers here, in the Solr docs and on the other SO question, I found that the following syntax produces the correct result for my use case

(my_field=my_value or my_field is null):

(my_field:"my_value" OR (*:* NOT my_field:*))

This works for solr 4.1.0. This is slightly different than the use case in the OP; but, I thought that others would find it useful.

Add column in dataframe from list

IIUC, if you make your (unfortunately named) List into an ndarray, you can simply index into it naturally.

>>> import numpy as np
>>> m = np.arange(16)*10
>>> m[df.A]
array([  0,  40,  50,  60, 150, 150, 140, 130])
>>> df["D"] = m[df.A]
>>> df
    A   B   C    D
0   0 NaN NaN    0
1   4 NaN NaN   40
2   5 NaN NaN   50
3   6 NaN NaN   60
4  15 NaN NaN  150
5  15 NaN NaN  150
6  14 NaN NaN  140
7  13 NaN NaN  130

Here I built a new m, but if you use m = np.asarray(List), the same thing should work: the values in df.A will pick out the appropriate elements of m.


Note that if you're using an old version of numpy, you might have to use m[df.A.values] instead-- in the past, numpy didn't play well with others, and some refactoring in pandas caused some headaches. Things have improved now.

Android TextView Text not getting wrapped

I added a \n in the middle of my string and it looked okay.

Clear screen in shell

Here's how to make your very own cls or clear command that will work without explicitly calling any function!

We'll take advantage of the fact that the python console calls repr() to display objects on screen. This is especially useful if you have your own customized python shell (with the -i option for example) and you have a pre-loading script for it. This is what you need:

import os
class ScreenCleaner:
    def __repr__(self):
        os.system('cls')  # This actually clears the screen
        return ''  # Because that's what repr() likes

cls = ScreenCleaner()

Use clear instead of cls if you're on linux (in both the os command and the variable name)!

Now if you just write cls or clear in the console - it will clear it! Not even cls() or clear() - just the raw variable. This is because python will call repr(cls) to print it out, which will in turn trigger our __repr__ function.

Let's test it out:

>>> df;sag
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'df' is not defined
>>> sglknas
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'sglknas' is not defined
>>> lksnldn
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'lksnldn' is not defined
>>> cls

And the screen is clear!

To clarify - the code above needs to either be imported in the console like this

from somefile import cls

Or pre load directly with something like:

python -i my_pre_loaded_classes.py

Iterating through a golang map

For example,

package main

import "fmt"

func main() {
    type Map1 map[string]interface{}
    type Map2 map[string]int
    m := Map1{"foo": Map2{"first": 1}, "boo": Map2{"second": 2}}
    //m = map[foo:map[first: 1] boo: map[second: 2]]
    fmt.Println("m:", m)
    for k, v := range m {
        fmt.Println("k:", k, "v:", v)
    }
}

Output:

m: map[boo:map[second:2] foo:map[first:1]]
k: boo v: map[second:2]
k: foo v: map[first:1]

Passing data between view controllers

Well, we have a few ways we can work with the delegates system or using storyboardSegue:

  1. As working with setter and getter methods, like in viewController.h

     @property (retain, nonatomic) NSString *str;
    

    Now, in viewController.m

    @synthesize str;
    

    Here I have a PDF URL and a segue to another viewController like this and pdfObject is my pdfModel. It is basically an NSOBJECT class.

     str = [NSString stringWithFormat:@"%@", pdfObject.objPath];
     NSLog(@"pdfUrl :***: %@ :***:", pdfUrl);
    
     [self performSegueWithIdentifier:@"programPDFViewController_segue" sender:self];
    
     #pragma mark - Navigation
    
     // In a storyboard-based application, you will often want to do a little preparation before navigation
    
     - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    
          if ([[segue identifier] isEqualToString:@"programPDFViewController_segue"]) {
              programPDFViewController *pdfVC = [segue destinationViewController];
              [pdfVC setRecievedPdfUrl:str];
          }
     }
    

    Now successfully I received my PDF URL string and other ViewController and use that string in webview...

  2. As working with delegates like this I have one NSObject class of utilities containing my methods of dateFormatter, sharedInstance, EscapeWhiteSpaceCharacters, convertImageToGrayScale and more method I worked with throughout the application so now in file utilities.h.

    In this, you don’t need to create variables every time parsing data from one to another view controller. One time, you create a string variable in file utilities.h.

    Just make it nil and use it again.

     @interface Utilities : NSObject
    

    File Utilities.h:

     +(Utilities*)sharedInstance;
    
     @property(nonatomic, retain)NSString* strUrl;
    

    Now in file utilities.m:

     @implementation utilities
    
     +(utilities*)sharedInstance
     {
         static utilities* sharedObj = nil;
         if (sharedObj == nil) {
             sharedObj = [[utilities alloc] init];
         }
         return sharedObj;
     }
    

    Now it's done, come to your file firstViewController.m and call the delegate

    NSString*str = [NSString stringWithFormat:@"%@", pdfObject.objPath];

    [Connection sharedInstance].strUrl = nil; [Connection sharedInstance].strUrl = str;

    Now go to you file secondViewController.m directly, and use it without creating a variable

    In viewwillapear what I did:

     -(void)viewWillAppear:(BOOL)animated {
         [super viewWillAppear:YES];
    
         [self webViewMethod:[Connection sharedInstance].strUrl];
     }
    
    
     -(void)WebViewMethod:(NSString)Url {
    
         // Working with webview. Enjoy coding :D
     }
    

This delegate work is reliable with memory management.

How can I add raw data body to an axios request?

The key is to use "Content-Type": "text/plain" as mentioned by @MadhuBhat.

axios.post(path, code, { headers: { "Content-Type": "text/plain" } }).then(response => {
    console.log(response);
});

A thing to note if you use .NET is that a raw string to a controller will return 415 Unsupported Media Type. To get around this you need to encapsulate the raw string in hyphens like this and send it as "Content-Type": "application/json":

axios.post(path, "\"" + code + "\"", { headers: { "Content-Type": "application/json" } }).then(response => {
    console.log(response);
});

C# Controller:

[HttpPost]
public async Task<ActionResult<string>> Post([FromBody] string code)
{
    return Ok(code);
}

https://weblog.west-wind.com/posts/2017/sep/14/accepting-raw-request-body-content-in-aspnet-core-api-controllers

You can also make a POST with query params if that helps:

.post(`/mails/users/sendVerificationMail`, null, { params: {
  mail,
  firstname
}})
.then(response => response.status)
.catch(err => console.warn(err));

This will POST an empty body with the two query params:

POST http://localhost:8000/api/mails/users/sendVerificationMail?mail=lol%40lol.com&firstname=myFirstName

Source: https://stackoverflow.com/a/53501339/3850405

Best way to check if a Data Table has a null value in it

I will do like....

(!DBNull.Value.Equals(dataSet.Tables[6].Rows[0]["_id"]))

Does a favicon have to be 32x32 or 16x16?

As I learned, no one of those several solutions are perfects. Using a favicon generator is indeed a good solution but their number is overwhelming and it's hard to choose. I d'like to add that if you want your website to be PWA enabled, you need to provide also a 512x512 icon as stated by Google Devs :

icons including a 192px and a 512px version

I didn't met a lot of favicon generators enforcing that criteria (firebase does, but there is a lot of things it doesn't do). So the solution must be a mix of many other solutions.

I don't know, today at the begining of 2020 if providing a 16x16, 32x32 still relevant. I guess it still matters in certain context like, for example, if your users still use IE for some reason (this stills happen in some privates companies which doesn't migrate to a newer browser for some reasons)

How can I compare strings in C using a `switch` statement?

Assuming little endianness and sizeof(char) == 1, you could do that (something like this was suggested by MikeBrom).

char* txt = "B1";
int tst = *(int*)txt;
if ((tst & 0x00FFFFFF) == '1B')
    printf("B1!\n");

It could be generalized for BE case.

How do I export an Android Studio project?

Windows:

First Open Command Window and set location of your android studio project folder like:

D:\MyApplication>

then type below command in it:

gradlew clean

then wait for complete clean process. after complete it now zip your project like below:

  • right click on your project folder
  • then select send to option now
  • select compressed via zip

How can I lock the first row and first column of a table when scrolling, possibly using JavaScript and CSS?

It's actually do-able without JavaScript, but using pure CSS + HTML with sticky position. Just add "position:sticky" to the cells you'd like to freeze.

For building a table, you can either use or CSS grid, and this technique works on both of them.

Here is an example formatting with table tag ( live demo here ):

<table>
  <tr><th class="head"></th class="head"><th></th> ... </tr>
  <tr><th class="head"></th>             <th></th> ... </tr>
...
</table>
<style type="text/css">
  .head { position: sticky; top: 0; left: 0;}
</style>

And here is an example with CSS Grid ( live demo here ):

<div class="grid">
   <!-- cells to freeze -->
   <div class="entry head"></div>
   <div class="entry head"></div>
   ...
   <!-- normal cells -->
   <div class="entry"></div>
   ...
</div>
<style type="text/css">
  .grid {
    display: grid;
    grid-template-columns: repeat(<your-cell-count>, <cell-size>); 
  } 
  .entry.head { position: sticky; top: 0; left: 0 }
</style>

You probably will need to take care of the cells frozen both horizontally and vertically ( e.g., setting a z-index larger than others ) but it will be still CSS thing.

I think the main drawback of this approach is, probably, the browser compatibility issue. Check Can I Use CSS-sticky and Can I use CSS grid before using these techniques.

How can I output the value of an enum class in C++11

#include <iostream>
#include <type_traits>

using namespace std;

enum class A {
  a = 1,
  b = 69,
  c= 666
};

std::ostream& operator << (std::ostream& os, const A& obj)
{
   os << static_cast<std::underlying_type<A>::type>(obj);
   return os;
}

int main () {
  A a = A::c;
  cout << a << endl;
}

How to make a stable two column layout in HTML/CSS

I could care less about IE6, as long as it works in IE8, Firefox 4, and Safari 5

This makes me happy.

Try this: Live Demo

display: table is surprisingly good. Once you don't care about IE7, you're free to use it. It doesn't really have any of the usual downsides of <table>.

CSS:

#container {
    background: #ccc;
    display: table
}
#left, #right {
    display: table-cell
}
#left {
    width: 150px;
    background: #f0f;
    border: 5px dotted blue;
}
#right {
    background: #aaa;
    border: 3px solid #000
}

@JsonProperty annotation on field as well as getter/setter

In addition to existing good answers, note that Jackson 1.9 improved handling by adding "property unification", meaning that ALL annotations from difference parts of a logical property are combined, using (hopefully) intuitive precedence.

In Jackson 1.8 and prior, only field and getter annotations were used when determining what and how to serialize (writing JSON); and only and setter annotations for deserialization (reading JSON). This sometimes required addition of "extra" annotations, like annotating both getter and setter.

With Jackson 1.9 and above these extra annotations are NOT needed. It is still possible to add those; and if different names are used, one can create "split" properties (serializing using one name, deserializing using other): this is occasionally useful for sort of renaming.

java.nio.file.Path for a classpath resource

It turns out you can do this, with the help of the built-in Zip File System provider. However, passing a resource URI directly to Paths.get won't work; instead, one must first create a zip filesystem for the jar URI without the entry name, then refer to the entry in that filesystem:

static Path resourceToPath(URL resource)
throws IOException,
       URISyntaxException {

    Objects.requireNonNull(resource, "Resource URL cannot be null");
    URI uri = resource.toURI();

    String scheme = uri.getScheme();
    if (scheme.equals("file")) {
        return Paths.get(uri);
    }

    if (!scheme.equals("jar")) {
        throw new IllegalArgumentException("Cannot convert to Path: " + uri);
    }

    String s = uri.toString();
    int separator = s.indexOf("!/");
    String entryName = s.substring(separator + 2);
    URI fileURI = URI.create(s.substring(0, separator));

    FileSystem fs = FileSystems.newFileSystem(fileURI,
        Collections.<String, Object>emptyMap());
    return fs.getPath(entryName);
}

Update:

It’s been rightly pointed out that the above code contains a resource leak, since the code opens a new FileSystem object but never closes it. The best approach is to pass a Consumer-like worker object, much like how Holger’s answer does it. Open the ZipFS FileSystem just long enough for the worker to do whatever it needs to do with the Path (as long as the worker doesn’t try to store the Path object for later use), then close the FileSystem.

Is there a way to style a TextView to uppercase all of its letters?

I've come up with a solution which is similar with RacZo's in the fact that I've also created a subclass of TextView which handles making the text upper-case.

The difference is that instead of overriding one of the setText() methods, I've used a similar approach to what the TextView actually does on API 14+ (which is in my point of view a cleaner solution).

If you look into the source, you'll see the implementation of setAllCaps():

public void setAllCaps(boolean allCaps) {
    if (allCaps) {
        setTransformationMethod(new AllCapsTransformationMethod(getContext()));
    } else {
        setTransformationMethod(null);
    }
}

The AllCapsTransformationMethod class is not (currently) public, but still, the source is also available. I've simplified that class a bit (removed the setLengthChangesAllowed() method), so the complete solution is this:

public class UpperCaseTextView extends TextView {

    public UpperCaseTextView(Context context) {
        super(context);
        setTransformationMethod(upperCaseTransformation);
    }

    public UpperCaseTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setTransformationMethod(upperCaseTransformation);
    }

    public UpperCaseTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setTransformationMethod(upperCaseTransformation);
    }

    private final TransformationMethod upperCaseTransformation =
            new TransformationMethod() {

        private final Locale locale = getResources().getConfiguration().locale;

        @Override
        public CharSequence getTransformation(CharSequence source, View view) {
            return source != null ? source.toString().toUpperCase(locale) : null;
        }

        @Override
        public void onFocusChanged(View view, CharSequence sourceText,
                boolean focused, int direction, Rect previouslyFocusedRect) {}
    };
}

Filtering Sharepoint Lists on a "Now" or "Today"

Have you tried this: create a Computed column, called 'Expiry', with a formula that amounts to '[Created] + 7 days'. Then use the computed column in your View's filter. Let us know whether this worked or what problems this poses!

Adding simple legend to plot in R

Take a look at ?legend and try this:

legend('topright', names(a)[-1] , 
   lty=1, col=c('red', 'blue', 'green',' brown'), bty='n', cex=.75)

enter image description here

push_back vs emplace_back

Specific use case for emplace_back: If you need to create a temporary object which will then be pushed into a container, use emplace_back instead of push_back. It will create the object in-place within the container.

Notes:

  1. push_back in the above case will create a temporary object and move it into the container. However, in-place construction used for emplace_back would be more performant than constructing and then moving the object (which generally involves some copying).
  2. In general, you can use emplace_back instead of push_back in all the cases without much issue. (See exceptions)

How to split elements of a list?

myList = [i.split('\t')[0] for i in myList] 

Android 8: Cleartext HTTP traffic not permitted

Update December 2019 ionic - 4.7.1

<manifest xmlns:tools=“http://schemas.android.com/tools”>

<application android:usesCleartextTraffic=“true” tools:targetApi=“28”>

Please add above content in android manifest .xml file

Previous Versions of ionic

  1. Make sure you have the following in your config.xml in Ionic Project:

    <edit-config file="app/src/main/AndroidManifest.xml" mode="merge" target="/manifest/application" xmlns:android="http://schemas.android.com/apk/res/android">
                <application android:networkSecurityConfig="@xml/network_security_config" />
                <application android:usesCleartextTraffic="true" />
            </edit-config>
    
  2. Run ionic Cordova build android. It creates Android folder under Platforms

  3. Open Android Studio and open the Android folder present in our project project-platforms-android. Leave it for few minutes so that it builds the gradle

  4. After gradle build is finished we get some errors for including minSdVersion in manifest.xml. Now what we do is just remove <uses-sdk android:minSdkVersion="19" /> from manifest.xml.

    Make sure its removed from both the locations:

    1. app → manifests → AndroidManifest.xml.
    2. CordovaLib → manifests → AndroidManifest.xml.

    Now try to build the gradle again and now it builds successfully

  5. Make sure you have the following in Application tag in App → manifest → Androidmanifest.xml:

    <application
    android:networkSecurityConfig="@xml/network_security_config"  android:usesCleartextTraffic="true" >
    
  6. Open network_security_config (app → res → xml → network_security_config.xml).

    Add the following code:

    <?xml version="1.0" encoding="utf-8"?>
    <network-security-config>
        <domain-config cleartextTrafficPermitted="true">
            <domain includeSubdomains="true">xxx.yyyy.com</domain>
        </domain-config>
    </network-security-config>
    

Here xxx.yyyy.com is the link of your HTTP API. Make sure you don't include any Http before the URL.

Note: Now build the app using Android Studio (Build -- Build Bundle's/APK -- Build APK) and now you can use that App and it works fine in Android Pie. If you try to build app using ionic Cordova build android it overrides all these settings so make sure you use Android Studio to build the Project.

If you have any older versions of app installed, Uninstall them and give a try or else you will be left with some error:

App not Installed

How to delete large data of table in SQL without log?

If i say without loop, i can use GOTO statement for delete large amount of records using sql server. exa.

 IsRepeat:
    DELETE TOP (10000)
    FROM <TableName>
    IF @@ROWCOUNT > 0
         GOTO IsRepeat

like this way you can delete large amount of data with smaller size of delete.

let me know if requires more information.

How to convert an address to a latitude/longitude?

Having rolled my own solution for this before, I can whole heartedly recommend the Geo::Coder::US Perl module for this. Just download all the census data and use the included importer to create the Berkeley DB for your country and point the Perl script at it. Use the module's built in address parsing, and there you have it: An offline geocoding system!

Heroku deployment error H10 (App crashed)

I had the same issue (same error on heroku, working on local machine) and I tried all the solutions listed here including heroku run rails console which ran without error messages. I tried heroku run rake db:migrate and heroku run rake db:migrate:reset a few times. None of this solved the problem. On going through some files that are used in production but not in dev environment, I found some whitespace in the puma.rb file to be the culprit. Hope this helps someone who has the same issue. Changing this made it work

  ActiveRecord::Base.establish_connection
  End

to

  ActiveRecord::Base.establish_connection
end

Writing data to a local text file with javascript

Our HTML:

<div id="addnew">
    <input type="text" id="id">
    <input type="text" id="content">
    <input type="button" value="Add" id="submit">
</div>

<div id="check">
    <input type="text" id="input">
    <input type="button" value="Search" id="search">
</div>

JS (writing to the txt file):

function writeToFile(d1, d2){
    var fso = new ActiveXObject("Scripting.FileSystemObject");
    var fh = fso.OpenTextFile("data.txt", 8, false, 0);
    fh.WriteLine(d1 + ',' + d2);
    fh.Close();
}
var submit = document.getElementById("submit");
submit.onclick = function () {
    var id      = document.getElementById("id").value;
    var content = document.getElementById("content").value;
    writeToFile(id, content);
}

checking a particular row:

function readFile(){
    var fso = new ActiveXObject("Scripting.FileSystemObject");
    var fh = fso.OpenTextFile("data.txt", 1, false, 0);
    var lines = "";
    while (!fh.AtEndOfStream) {
        lines += fh.ReadLine() + "\r";
    }
    fh.Close();
    return lines;
}
var search = document.getElementById("search");
search.onclick = function () {
    var input   = document.getElementById("input").value;
    if (input != "") {
        var text    = readFile();
        var lines   = text.split("\r");
        lines.pop();
        var result;
        for (var i = 0; i < lines.length; i++) {
            if (lines[i].match(new RegExp(input))) {
                result = "Found: " + lines[i].split(",")[1];
            }
        }
        if (result) { alert(result); }
        else { alert(input + " not found!"); }
    }
}

Put these inside a .hta file and run it. Tested on W7, IE11. It's working. Also if you want me to explain what's going on, say so.

Constants in Objective-C

A slight modification of the suggestion of @Krizz, so that it works properly if the constants header file is to be included in the PCH, which is rather normal. Since the original is imported into the PCH, it won't reload it into the .m file and thus you get no symbols and the linker is unhappy.

However, the following modification allows it to work. It's a bit convoluted, but it works.

You'll need 3 files, .h file which has the constant definitions, the .h file and the .m file, I'll use ConstantList.h, Constants.h and Constants.m, respectively. the contents of Constants.h are simply:

// Constants.h
#define STR_CONST(name, value) extern NSString* const name
#include "ConstantList.h"

and the Constants.m file looks like:

// Constants.m
#ifdef STR_CONST
    #undef STR_CONST
#endif
#define STR_CONST(name, value) NSString* const name = @ value
#include "ConstantList.h"

Finally, the ConstantList.h file has the actual declarations in it and that is all:

// ConstantList.h
STR_CONST(kMyConstant, "Value");
…

A couple of things to note:

  1. I had to redefine the macro in the .m file after #undefing it for the macro to be used.

  2. I also had to use #include instead of #import for this to work properly and avoid the compiler seeing the previously precompiled values.

  3. This will require a recompile of your PCH (and probably the entire project) whenever any values are changed, which is not the case if they are separated (and duplicated) as normal.

Hope that is helpful for someone.

Rails: How does the respond_to block work?

There is one more thing you should be aware of - MIME.

If you need to use a MIME type and it isn't supported by default, you can register your own handlers in config/initializers/mime_types.rb:

Mime::Type.register "text/markdown", :markdown

What issues should be considered when overriding equals and hashCode in Java?

There are some issues worth noticing if you're dealing with classes that are persisted using an Object-Relationship Mapper (ORM) like Hibernate, if you didn't think this was unreasonably complicated already!

Lazy loaded objects are subclasses

If your objects are persisted using an ORM, in many cases you will be dealing with dynamic proxies to avoid loading object too early from the data store. These proxies are implemented as subclasses of your own class. This means thatthis.getClass() == o.getClass() will return false. For example:

Person saved = new Person("John Doe");
Long key = dao.save(saved);
dao.flush();
Person retrieved = dao.retrieve(key);
saved.getClass().equals(retrieved.getClass()); // Will return false if Person is loaded lazy

If you're dealing with an ORM, using o instanceof Person is the only thing that will behave correctly.

Lazy loaded objects have null-fields

ORMs usually use the getters to force loading of lazy loaded objects. This means that person.name will be null if person is lazy loaded, even if person.getName() forces loading and returns "John Doe". In my experience, this crops up more often in hashCode() and equals().

If you're dealing with an ORM, make sure to always use getters, and never field references in hashCode() and equals().

Saving an object will change its state

Persistent objects often use a id field to hold the key of the object. This field will be automatically updated when an object is first saved. Don't use an id field in hashCode(). But you can use it in equals().

A pattern I often use is

if (this.getId() == null) {
    return this == other;
}
else {
    return this.getId().equals(other.getId());
}

But: you cannot include getId() in hashCode(). If you do, when an object is persisted, its hashCode changes. If the object is in a HashSet, you'll "never" find it again.

In my Person example, I probably would use getName() for hashCode and getId() plus getName() (just for paranoia) for equals(). It's okay if there are some risk of "collisions" for hashCode(), but never okay for equals().

hashCode() should use the non-changing subset of properties from equals()

What is the difference between HAVING and WHERE in SQL?

HAVING: is used to check conditions after the aggregation takes place.
WHERE: is used to check conditions before the aggregation takes place.

This code:

select City, CNT=Count(1)
From Address
Where State = 'MA'
Group By City

Gives you a table of all cities in MA and the number of addresses in each city.

This code:

select City, CNT=Count(1)
From Address
Where State = 'MA'
Group By City
Having Count(1)>5

Gives you a table of cities in MA with more than 5 addresses and the number of addresses in each city.

nginx showing blank PHP pages

Many users fall in this thread expecting to find a solution for blank pages being displayed while using nginx+php-fpm, me being one of them. This is a recap of what I ended up doing after reading many of the answers here plus my own investigations (updated to php7.2):

1) Open /etc/php/7.2/fpm/pool.d/www.conf and check the value of parameter listen.

listen = /var/run/php/php7.2-fpm.sock

2) Parameter listen should match fastcgi_pass parameter in your site configuration file (i,e: /etc/nginx/sites-enabled/default).

fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;

3) Check the file actually exists:

$ file /var/run/php/php7.2-fpm.sock 
/var/run/php/php7.2-fpm.sock: socket

4) If it doesn't exist that means php7.2-fpm is not running, so you need to restart it:

$ sudo /etc/init.d/php7.2-fpm restart
[ ok ] Restarting php7.2-fpm (via systemctl): php7.2-fpm.service.


With regard to the location section in /etc/nginx/sites-enabled/default:

   # pass PHP scripts to FastCGI server
   #
   location ~ \.php$ {
      include snippets/fastcgi-php.conf;

      # With php-fpm (or other unix sockets):
      fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
   }

Check the file snippets/fastcgi-php.conf exists at location /etc/nginx/:

$ file /etc/nginx/snippets/fastcgi-php.conf
/etc/nginx/snippets/fastcgi-php.conf: ASCII text

This file contains a list of variable definitions required by php7.2-fpm. The variables are defined directly or through an include of a separated file.

 include fastcgi.conf;

This file is located at /etc/nginx/fastcgi.conf and it looks like:

fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
...
fastcgi_param  REDIRECT_STATUS    200;

nginx includes two possible parameter files: fastcgi_params and fastcgi.conf. The difference between both is the definition of variable SCRIPT_FILENAME:

$ diff fastcgi_params fastcgi.conf 
1a2
> fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;

To make a long story short, fastcgi.conf should always work. If for some reason you're set up is using fastcgi_params, you should define SCRIPT_FILENAME:

location ~ \.php$ {
  include snippets/fastcgi-php.conf;

  # With php-fpm (or other unix sockets):
  fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;

  fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;
}

Now reload nginx configuration:

$ sudo nginx -s reload

And check a php file is displayed correctly. For instance:

/var/www/html/test.php

<pre><?php var_export($_SERVER)?></pre>

Where /var/www/html is the path to the document root.

If despite all that, you're still seeing a blank file, make sure your php.ini has short_open_tag enabled (if you're testing a PHP page with short tags).

How to use workbook.saveas with automatic Overwrite

To hide the prompt set xls.DisplayAlerts = False

ConflictResolution is not a true or false property, it should be xlLocalSessionChanges

Note that this has nothing to do with displaying the Overwrite prompt though!

Set xls = CreateObject("Excel.Application")    
xls.DisplayAlerts = False
Set wb = xls.Workbooks.Add
fullFilePath = importFolderPath & "\" & "A.xlsx"

wb.SaveAs fullFilePath, AccessMode:=xlExclusive,ConflictResolution:=Excel.XlSaveConflictResolution.xlLocalSessionChanges    
wb.Close (True)

Cannot read configuration file due to insufficient permissions

I had the same problem when I tried to share the site root folder with another user. Some folder lost the permission. So I followed the steps to add permission to IIS_IUSRS group as suggested by Afshin Gh. The problem is this group was not available for me. I am using windows 7.

What I did I just changed some steps:

  1. Right click on the parent folder (who lost the permission),
  2. Properties => Security =>In "Group or user names:",
  3. Click Edit...
  4. Window "Permission for your folder" will be opened.
  5. In "Group or user names:" press ADD... btn,
  6. Type Authen and press Check Names,
  7. You will see the complete group name "Authenticated Users"
  8. Press ok => apply.
  9. This should enable privileges again.

That worked for me.

Unresolved Import Issues with PyDev and Eclipse

I had some issues importing additional libraries, after trying to resolve the problem, by understanding PYTHONPATH, Interpreter, and Grammar I found that I did everything write but the problems continue. After that, I just add a new empty line in the files that had the import errors and saved them and the error was resolved.

Android Layout Weight

android:Layout_weight can be used when you don't attach a fix value to your width already like fill_parent etc.

Do something like this :

<Button>

Android:layout_width="0dp"
Android:layout_weight=1

-----other parameters
</Button>

display HTML page after loading complete

Hide the body initially, and then show it with jQuery after it has loaded.

body {
    display: none;
}

$(function () {
    $('body').show();
}); // end ready

Also, it would be best to have $('body').show(); as the last line in your last and main .js file.

Quick way to list all files in Amazon S3 bucket?

Alternatively you can use Minio Client aka mc. Its Open Source and compatible with AWS S3. It is available for Linux, Windows, Mac, FreeBSD.

All you have do do is to run mc ls command for listing the contents.

$ mc ls s3/kline/
[2016-04-30 13:20:47 IST] 1.1MiB 1.jpg
[2016-04-30 16:03:55 IST] 7.5KiB docker.png
[2016-04-30 15:16:17 IST]  50KiB pi.png
[2016-05-10 14:34:39 IST] 365KiB upton.pdf

Note:

  • s3: Alias for Amazon S3
  • kline: AWS S3 bucket name

Installing Minio Client Linux Download mc for:

$ chmod 755 mc
$ ./mc --help

Setting up AWS credentials with Minio Client

$ mc config host add mys3 https://s3.amazonaws.com BKIKJAA5BMMU2RHO6IBB V7f1CwQqAcwo80UEIJEjc5gVQUSSx5ohQ9GSrr12

Note: Please replace mys3 with alias you would like for this account and ,BKIKJAA5BMMU2RHO6IBB, V7f1CwQqAcwo80UEIJEjc5gVQUSSx5ohQ9GSrr12 with your AWS ACCESS-KEY and SECRET-KEY

Hope it helps.

Disclaimer: I work for Minio

Is there a way to programmatically scroll a scroll view to a specific edit text?

Another varition would be:

scrollView.postDelayed(new Runnable()
{
    @Override
    public void run()
    {
        scrollView.smoothScrollTo(0, img_transparent.getTop());
    }
}, 2000);

or you can use the post() method.

In C#, can a class inherit from another class and an interface?

Yes. Try:

class USBDevice : GenericDevice, IOurDevice

Note: The base class should come before the list of interface names.

Of course, you'll still need to implement all the members that the interfaces define. However, if the base class contains a member that matches an interface member, the base class member can work as the implementation of the interface member and you are not required to manually implement it again.

How do I base64 encode a string efficiently using Excel VBA?

As Mark C points out, you can use the MSXML Base64 encoding functionality as described here.

I prefer late binding because it's easier to deploy, so here's the same function that will work without any VBA references:

Function EncodeBase64(text As String) As String
  Dim arrData() As Byte
  arrData = StrConv(text, vbFromUnicode)

  Dim objXML As Variant
  Dim objNode As Variant

  Set objXML = CreateObject("MSXML2.DOMDocument")
  Set objNode = objXML.createElement("b64")

  objNode.dataType = "bin.base64"
  objNode.nodeTypedValue = arrData
  EncodeBase64 = objNode.text

  Set objNode = Nothing
  Set objXML = Nothing
End Function

How to get row count using ResultSet in Java?

Most drivers support forward only resultset - so method like last, beforeFirst etc are not supported.

The first approach is suitable if you are also getting the data in the same loop - otherwise the resultSet has already been iterated and can not be used again.

In most cases the requirement is to get the number of rows a query would return without fetching the rows. Iterating through the result set to find the row count is almost same as processing the data. It is better to do another count(*) query instead.

HashMaps and Null values?

HashMap supports both null keys and values

http://docs.oracle.com/javase/6/docs/api/java/util/HashMap.html

... and permits null values and the null key

So your problem is probably not the map itself.

docker error - 'name is already in use by container'

Ok, so I didn't understand either, then I left my pc, went to do other things, and upon my return, it clicked :D

  1. You download a docker image file. docker pull *image-name* will just pull the image from docker hub without running it.

  2. Now, you use docker run, and give it a name (e.g. newWebServer).

    docker run -d -p 8080:8080 -v volume --name newWebServer image-name/version

You perhaps only need docker run --name *name* *image*, but the other stuff will become useful quickly.

-d (detached) - means the container will exit when the root process used to run the container exits.

-p (port) - specify the container port and the host port. Kind of the internal and external port. The internal one being the port the container uses, and the external one is the port you use outside of it and probably the one you need to put in your web browser if that's how you access your app.

--name (what you want to call this instance of the container) - you could have several instances of the same container all with different names, which is useful when you're trying to test something.

image-name/version is the actual image you want to create the container from. You can see a list of all the images on your system with docker images -a. You may have more than one version, so make sure you choose the correct one/tag.

-v (volume) - perhaps not needed initially, but soon you'll want to persist data after your container exits.

OK. So now, docker run just created a container from your image. If it isn't running, you can now start it with it's name:

docker start newWebServer

You can check all your containers (they may or may not be running) with

docker ps -a

You can stop and start them (or pause them) with their name or the container id (or just the first few characters of it) from the CONTAINER ID column e.g:

docker stop newWebServer

docker start c3028a89462c

And list all your images, with

docker images -a

In a nutshell, download an image; docker run creates a container from it; start it with docker start (name or container id); stop it with docker stop (name or container id).

How to split a data frame?

Splitting the data frame seems counter-productive. Instead, use the split-apply-combine paradigm, e.g., generate some data

df = data.frame(grp=sample(letters, 100, TRUE), x=rnorm(100))

then split only the relevant columns and apply the scale() function to x in each group, and combine the results (using split<- or ave)

df$z = 0
split(df$z, df$grp) = lapply(split(df$x, df$grp), scale)
## alternative: df$z = ave(df$x, df$grp, FUN=scale)

This will be very fast compared to splitting data.frames, and the result remains usable in downstream analysis without iteration. I think the dplyr syntax is

library(dplyr)
df %>% group_by(grp) %>% mutate(z=scale(x))

In general this dplyr solution is faster than splitting data frames but not as fast as split-apply-combine.

Get the current file name in gulp.src()

You can use the gulp-filenames module to get the array of paths. You can even group them by namespaces:

var filenames = require("gulp-filenames");

gulp.src("./src/*.coffee")
    .pipe(filenames("coffeescript"))
    .pipe(gulp.dest("./dist"));

gulp.src("./src/*.js")
  .pipe(filenames("javascript"))
  .pipe(gulp.dest("./dist"));

filenames.get("coffeescript") // ["a.coffee","b.coffee"]  
                              // Do Something With it 

When to use @QueryParam vs @PathParam

REST may not be a standard as such, but reading up on general REST documentation and blog posts should give you some guidelines for a good way to structure API URLs. Most rest APIs tend to only have resource names and resource IDs in the path. Such as:

/departments/{dept}/employees/{id}

Some REST APIs use query strings for filtering, pagination and sorting, but Since REST isn't a strict standard I'd recommend checking some REST APIs out there such as github and stackoverflow and see what could work well for your use case.

I'd recommend putting any required parameters in the path, and any optional parameters should certainly be query string parameters. Putting optional parameters in the path will end up getting really messy when trying to write URL handlers that match different combinations.

how do I initialize a float to its max/min value?

You can either use -FLT_MAX (or -DBL_MAX) for the maximum magnitude negative number and FLT_MAX (or DBL_MAX) for positive. This gives you the range of possible float (or double) values.

You probably don't want to use FLT_MIN; it corresponds to the smallest magnitude positive number that can be represented with a float, not the most negative value representable with a float.

FLT_MIN and FLT_MAX correspond to std::numeric_limits<float>::min() and std::numeric_limits<float>::max().

WPF Label Foreground Color

I checked your XAML, it works fine - e.g. both labels have a gray foreground.
My guess is that you have some style which is affecting the way it looks...

Try moving your XAML to a brand-new window and see for yourself... Then, check if you have any themes or styles (in the Window.Resources for instance) which might be affecting the labels...

The relationship could not be changed because one or more of the foreign-key properties is non-nullable

I've tried these solutions and many others, but none of them quite worked out. Since this is the first answer on google, I'll add my solution here.

The method that worked well for me was to take relationships out of the picture during commits, so there was nothing for EF to screw up. I did this by re-finding the parent object in the DBContext, and deleting that. Since the re-found object's navigation properties are all null, the childrens' relationships are ignored during the commit.

var toDelete = db.Parents.Find(parentObject.ID);
db.Parents.Remove(toDelete);
db.SaveChanges();

Note that this assumes the foreign keys are setup with ON DELETE CASCADE, so when the parent row is removed, the children will be cleaned up by the database.

"Insufficient Storage Available" even there is lot of free space in device memory

Here's a very simple solution that works on my Samsung Galaxy S II and Note 1; I have no idea about other models:

  1. Open the phone app and switch to keypad.
  2. Dial *#9900#
  3. On the screen that appears, click on the button labelled "Delete dumpstate/logcat".

I've restored about one GB of system space this way.

how to find my angular version in my project?

define VERSION variable and import version into it.

import { VERSION } from '@angular/core';

Now you can use VERSION variable in your code to print version For example,

console.log(VERSION.full); 

How to stop "setInterval"

You have to store the timer id of the interval when you start it, you will use this value later to stop it, using the clearInterval function:

$(function () {
  var timerId = 0;

  $('textarea').focus(function () {
    timerId = setInterval(function () {
      // interval function body
    }, 1000);
  });

  $('textarea').blur(function () {
    clearInterval(timerId);
  });

});

Convert json to a C# array?

Old question but worth adding an answer if using .NET Core 3.0 or later. JSON serialization/deserialization is built into the framework (System.Text.Json), so you don't have to use third party libraries any more. Here's an example based off the top answer given by @Icarus

using System;
using System.Collections.Generic;

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            var json = "[{\"Name\":\"John Smith\", \"Age\":35}, {\"Name\":\"Pablo Perez\", \"Age\":34}]";

            // use the built in Json deserializer to convert the string to a list of Person objects
            var people = System.Text.Json.JsonSerializer.Deserialize<List<Person>>(json);

            foreach (var person in people)
            {
                Console.WriteLine(person.Name + " is " + person.Age + " years old.");
            }
        }

        public class Person
        {
            public int Age { get; set; }
            public string Name { get; set; }
        }
    }
}

Postman addon's like in firefox

I liked PostMan, it was the main reason why I kept using Chrome, now I'm good with HttpRequester

https://addons.mozilla.org/En-us/firefox/addon/httprequester/?src=search

A python class that acts like dict

I really don't see the right answer to this anywhere

class MyClass(dict):
    
    def __init__(self, a_property):
        self[a_property] = a_property

All you are really having to do is define your own __init__ - that really is all that there is too it.

Another example (little more complex):

class MyClass(dict):

    def __init__(self, planet):
        self[planet] = planet
        info = self.do_something_that_returns_a_dict()
        if info:
            for k, v in info.items():
                self[k] = v

    def do_something_that_returns_a_dict(self):
        return {"mercury": "venus", "mars": "jupiter"}

This last example is handy when you want to embed some kind of logic.

Anyway... in short class GiveYourClassAName(dict) is enough to make your class act like a dict. Any dict operation you do on self will be just like a regular dict.

Where is the WPF Numeric UpDown control?

Here is another open source control that has many different input methods (mouse drag, mouse wheel, cursor keys, textbox editing), supports many data types and use cases:

https://github.com/Dirkster99/NumericUpDownLib

What is %2C in a URL?

It's the ASCII keycode in hexadecimal for a comma (,).

i.e. , = %2C

like in my link suppose i want to order by two fields means in my link it will come like

order_by=id%2Cname which is equal to order_by=id,name .

How to select rows with NaN in particular column?

Try the following:

df[df['Col2'].isnull()]

Algorithm to convert RGB to HSV and HSV to RGB in range 0-255 for both

Here is an online converter with an article after explaining all the algorithms for color conversion.

You probably would prefer a ready-made C version but it should not be long to apply and it could help other people trying to do the same in another language or with another color space.

Download the Android SDK components for offline install

follow this video https://www.youtube.com/watch?v=883HjO06_E0 for how to download and install Android SDK components manually

Differences between SP initiated SSO and IDP initiated SSO

https://support.procore.com/faq/what-is-the-difference-between-sp-and-idp-initiated-sso

There is much more to this but this is a high level overview on which is which.

Procore supports both SP- and IdP-initiated SSO:

Identity Provider Initiated (IdP-initiated) SSO. With this option, your end users must log into your Identity Provider's SSO page (e.g., Okta, OneLogin, or Microsoft Azure AD) and then click an icon to log into and open the Procore web application. To configure this solution, see Configure IdP-Initiated SSO for Microsoft Azure AD, Configure Procore for IdP-Initated Okta SSO, or Configure IdP-Initiated SSO for OneLogin. OR Service Provider Initiated (SP-initiated) SSO. Referred to as Procore-initiated SSO, this option gives your end users the ability to sign into the Procore Login page and then sends an authorization request to the Identify Provider (e.g., Okta, OneLogin, or Microsoft Azure AD). Once the IdP authenticates the user's identify, the user is logged into Procore. To configure this solution, see Configure Procore-Initiated SSO for Microsoft Azure Active Directory, Configure Procore-Initiated SSO for Okta, or Configure Procore-Initiated SSO for OneLogin.

Difference between socket and websocket?

Regarding your question (b), be aware that the Websocket specification hasn't been finalised. According to the W3C:

Implementors should be aware that this specification is not stable.

Personally I regard Websockets to be waaay too bleeding edge to use at present. Though I'll probably find them useful in a year or so.

Overriding interface property type defined in Typescript d.ts file

I have created this type that allows me to easily override nested interfaces:

export type DeepPartialAny<T> = {
  [P in keyof T]?: T[P] extends Obj ? DeepPartialAny<T[P]> : any;
};

export type Override<A extends Obj, AOverride extends DeepPartialAny<A>> = { [K in keyof A]:
  AOverride[K] extends never
    ? A[K]
    : AOverride[K] extends Obj
    ? Override<A[K], AOverride[K]>
    : AOverride[K]
};

And then you can use it like that:

interface Foo {
  Bar: {
    Baz: string;
  };
}
type Foo2 = Override<Foo, { Bar: { Baz: number } }>;

const bar: Foo2['Bar']['Baz'] = 1; // number;

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

I believe you can set the SVN_USER environment variable to change your SVN username.

How to read a file in reverse order?

A correct, efficient answer written as a generator.

import os

def reverse_readline(filename, buf_size=8192):
    """A generator that returns the lines of a file in reverse order"""
    with open(filename) as fh:
        segment = None
        offset = 0
        fh.seek(0, os.SEEK_END)
        file_size = remaining_size = fh.tell()
        while remaining_size > 0:
            offset = min(file_size, offset + buf_size)
            fh.seek(file_size - offset)
            buffer = fh.read(min(remaining_size, buf_size))
            remaining_size -= buf_size
            lines = buffer.split('\n')
            # The first line of the buffer is probably not a complete line so
            # we'll save it and append it to the last line of the next buffer
            # we read
            if segment is not None:
                # If the previous chunk starts right from the beginning of line
                # do not concat the segment to the last line of new chunk.
                # Instead, yield the segment first 
                if buffer[-1] != '\n':
                    lines[-1] += segment
                else:
                    yield segment
            segment = lines[0]
            for index in range(len(lines) - 1, 0, -1):
                if lines[index]:
                    yield lines[index]
        # Don't yield None if the file was empty
        if segment is not None:
            yield segment

Download and save PDF file with Python requests module

Please note I'm a beginner. If My solution is wrong, please feel free to correct and/or let me know. I may learn something new too.

My solution:

Change the downloadPath accordingly to where you want your file to be saved. Feel free to use the absolute path too for your usage.

Save the below as downloadFile.py.

Usage: python downloadFile.py url-of-the-file-to-download new-file-name.extension

Remember to add an extension!

Example usage: python downloadFile.py http://www.google.co.uk google.html

import requests
import sys
import os

def downloadFile(url, fileName):
    with open(fileName, "wb") as file:
        response = requests.get(url)
        file.write(response.content)


scriptPath = sys.path[0]
downloadPath = os.path.join(scriptPath, '../Downloads/')
url = sys.argv[1]
fileName = sys.argv[2]      
print('path of the script: ' + scriptPath)
print('downloading file to: ' + downloadPath)
downloadFile(url, downloadPath + fileName)
print('file downloaded...')
print('exiting program...')

Sending email in .NET through Gmail

To avoid security issues in Gmail, you should generate an app password first from your Gmail settings and you can use this password instead of a real password to send an email even if you use two steps verification.

Get local IP address

This is the best code I found to get the current IP, avoiding get VMWare host or other invalid IP address.

public string GetLocalIpAddress()
{
    UnicastIPAddressInformation mostSuitableIp = null;

    var networkInterfaces = NetworkInterface.GetAllNetworkInterfaces();

    foreach (var network in networkInterfaces)
    {
        if (network.OperationalStatus != OperationalStatus.Up)
            continue;

        var properties = network.GetIPProperties();

        if (properties.GatewayAddresses.Count == 0)
            continue;

        foreach (var address in properties.UnicastAddresses)
        {
            if (address.Address.AddressFamily != AddressFamily.InterNetwork)
                continue;

            if (IPAddress.IsLoopback(address.Address))
                continue;

            if (!address.IsDnsEligible)
            {
                if (mostSuitableIp == null)
                    mostSuitableIp = address;
                continue;
            }

            // The best IP is the IP got from DHCP server
            if (address.PrefixOrigin != PrefixOrigin.Dhcp)
            {
                if (mostSuitableIp == null || !mostSuitableIp.IsDnsEligible)
                    mostSuitableIp = address;
                continue;
            }

            return address.Address.ToString();
        }
    }

    return mostSuitableIp != null 
        ? mostSuitableIp.Address.ToString()
        : "";
}

Angularjs: Get element in controller

Create custom directive

masterApp.directive('ngRenderCallback', function() {
    return {
        restrict: "A",
        link: function ($scope, element, attrs) {
            setTimeout(function(){ 
                $scope[attrs.ngEl] = element[0];
                $scope.$eval(attrs.ngRenderCallback);               
            }, 30);
        }
    }
});

code for html template

<div ng-render-callback="fnRenderCarousel('carouselA')" ng-el="carouselA"></div>

function in controller

$scope.fnRenderCarousel = function(elName){
    $($scope[elName]).carousel();
}

What are the benefits to marking a field as `readonly` in C#?

There are no apparent performance benefits to using readonly, at least none that I've ever seen mentioned anywhere. It's just for doing exactly as you suggest, for preventing modification once it has been initialised.

So it's beneficial in that it helps you write more robust, more readable code. The real benefit of things like this come when you're working in a team or for maintenance. Declaring something as readonly is akin to putting a contract for that variable's usage in the code. Think of it as adding documentation in the same way as other keywords like internal or private, you're saying "this variable should not be modified after initialisation", and moreover you're enforcing it.

So if you create a class and mark some member variables readonly by design, then you prevent yourself or another team member making a mistake later on when they're expanding upon or modifying your class. In my opinion, that's a benefit worth having (at the small expense of extra language complexity as doofledorfer mentions in the comments).

Remove all padding and margin table HTML and CSS

Remove padding between cells inside the table. Just use cellpadding=0 and cellspacing=0 attributes in table tag.

Make a float only show two decimal places

Another method for Swift (without using NSString):

let percentage = 33.3333
let text = String.localizedStringWithFormat("%.02f %@", percentage, "%")

P.S. this solution is not working with CGFloat type only tested with Float & Double

Markdown: continue numbered list

Note that there are also a number of extensions available that will fix this behaviour for specific contexts of Markdown use.

For example, sane_lists extension of python-markdown (used in mkdocs, for example), will recognize numbers used in Markdown lists. You just need to enable this extension arkdown.markdown(some_text, extensions=['sane_lists'])

Tomcat Server Error - Port 8080 already in use

If you want to regain the 8080 port number you do so by opening the task manager and then process tab, right click java.exe process and click on end process as shown in image attached.

screen shot

Performing Breadth First Search recursively

Following is my code for completely recursive implementation of breadth-first-search of a bidirectional graph without using loop and queue.

public class Graph { public int V; public LinkedList<Integer> adj[]; Graph(int v) { V = v; adj = new LinkedList[v]; for (int i=0; i<v; ++i) adj[i] = new LinkedList<>(); } void addEdge(int v,int w) { adj[v].add(w); adj[w].add(v); } public LinkedList<Integer> getAdjVerted(int vertex) { return adj[vertex]; } public String toString() { String s = ""; for (int i=0;i<adj.length;i++) { s = s +"\n"+i +"-->"+ adj[i] ; } return s; } } //BFS IMPLEMENTATION public static void recursiveBFS(Graph graph, int vertex,boolean visited[], boolean isAdjPrinted[]) { if (!visited[vertex]) { System.out.print(vertex +" "); visited[vertex] = true; } if(!isAdjPrinted[vertex]) { isAdjPrinted[vertex] = true; List<Integer> adjList = graph.getAdjVerted(vertex); printAdjecent(graph, adjList, visited, 0,isAdjPrinted); } } public static void recursiveBFS(Graph graph, List<Integer> vertexList, boolean visited[], int i, boolean isAdjPrinted[]) { if (i < vertexList.size()) { recursiveBFS(graph, vertexList.get(i), visited, isAdjPrinted); recursiveBFS(graph, vertexList, visited, i+1, isAdjPrinted); } } public static void printAdjecent(Graph graph, List<Integer> list, boolean visited[], int i, boolean isAdjPrinted[]) { if (i < list.size()) { if (!visited[list.get(i)]) { System.out.print(list.get(i)+" "); visited[list.get(i)] = true; } printAdjecent(graph, list, visited, i+1, isAdjPrinted); } else { recursiveBFS(graph, list, visited, 0, isAdjPrinted); } }

How to push to History in React Router v4?

you can use it like this as i do it for login and manny different things

class Login extends Component {
  constructor(props){
    super(props);
    this.login=this.login.bind(this)
  }


  login(){
this.props.history.push('/dashboard');
  }


render() {

    return (

   <div>
    <button onClick={this.login}>login</login>
    </div>

)

Add custom header in HttpWebRequest

A simple method of creating the service, adding headers and reading the JSON response,

private static void WebRequest()
    {
        const string WEBSERVICE_URL = "<<Web service URL>>";
        try
        {
            var webRequest = System.Net.WebRequest.Create(WEBSERVICE_URL);
            if (webRequest != null)
            {
                webRequest.Method = "GET";
                webRequest.Timeout = 12000;
                webRequest.ContentType = "application/json";
                webRequest.Headers.Add("Authorization", "Basic dchZ2VudDM6cGFdGVzC5zc3dvmQ=");

                using (System.IO.Stream s = webRequest.GetResponse().GetResponseStream())
                {
                    using (System.IO.StreamReader sr = new System.IO.StreamReader(s))
                    {
                        var jsonResponse = sr.ReadToEnd();
                        Console.WriteLine(String.Format("Response: {0}", jsonResponse));
                    }
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
    }

How to export table as CSV with headings on Postgresql?

Try this: "COPY products_273 FROM '\tmp\products_199.csv' DELIMITER ',' CSV HEADER"

The module was expected to contain an assembly manifest

Check if the manifest is a valid xml file. I had the same problem by doing a DOS copy command at the end of the build, and it turns out that for some reason I can not understand "copy" was adding a strange character (->) at the end of the manifest files. The problem was solved by adding "/b" switch to force binary copy.

Why do Python's math.ceil() and math.floor() operations return floats instead of integers?

Because python's math library is a thin wrapper around the C math library which returns floats.

Python element-wise tuple operations like sum

simple solution without class definition that returns tuple

import operator
tuple(map(operator.add,a,b))

Creating a simple XML file using python

For such a simple XML structure, you may not want to involve a full blown XML module. Consider a string template for the simplest structures, or Jinja for something a little more complex. Jinja can handle looping over a list of data to produce the inner xml of your document list. That is a bit trickier with raw python string templates

For a Jinja example, see my answer to a similar question.

Here is an example of generating your xml with string templates.

import string
from xml.sax.saxutils import escape

inner_template = string.Template('    <field${id} name="${name}">${value}</field${id}>')

outer_template = string.Template("""<root>
 <doc>
${document_list}
 </doc>
</root>
 """)

data = [
    (1, 'foo', 'The value for the foo document'),
    (2, 'bar', 'The <value> for the <bar> document'),
]

inner_contents = [inner_template.substitute(id=id, name=name, value=escape(value)) for (id, name, value) in data]
result = outer_template.substitute(document_list='\n'.join(inner_contents))
print result

Output:

<root>
 <doc>
    <field1 name="foo">The value for the foo document</field1>
    <field2 name="bar">The &lt;value&gt; for the &lt;bar&gt; document</field2>
 </doc>
</root>

The downer of the template approach is that you won't get escaping of < and > for free. I danced around that problem by pulling in a util from xml.sax

BigDecimal setScale and round

One important point that is alluded to but not directly addressed is the difference between "precision" and "scale" and how they are used in the two statements. "precision" is the total number of significant digits in a number. "scale" is the number of digits to the right of the decimal point.

The MathContext constructor only accepts precision and RoundingMode as arguments, and therefore scale is never specified in the first statement.

setScale() obviously accepts scale as an argument, as well as RoundingMode, however precision is never specified in the second statement.

If you move the decimal point one place to the right, the difference will become clear:

// 1.
new BigDecimal("35.3456").round(new MathContext(4, RoundingMode.HALF_UP));
//result = 35.35
// 2.
new BigDecimal("35.3456").setScale(4, RoundingMode.HALF_UP);
// result = 35.3456

How to calculate growth with a positive and negative number?

Simplest method is the one I would use.

=(ThisYear - LastYear)/(ABS(LastYear))

However it only works in certain situations. With certain values the results will be inverted.

Deleting specific rows from DataTable

<asp:GridView ID="grd_item_list" runat="server" AutoGenerateColumns="false" Width="100%" CssClass="table table-bordered table-hover" OnRowCommand="grd_item_list_RowCommand">
    <Columns>
        <asp:TemplateField HeaderText="No">
            <ItemTemplate>
                <%# Container.DataItemIndex + 1 %>
            </ItemTemplate>
        </asp:TemplateField>            
        <asp:TemplateField HeaderText="Actions">
            <ItemTemplate>                    
                <asp:Button ID="remove_itemIndex" OnClientClick="if(confirm('Are You Sure to delete?')==true){ return true;} else{ return false;}" runat="server" class="btn btn-primary" Text="REMOVE" CommandName="REMOVE_ITEM" CommandArgument='<%# Container.DataItemIndex+1 %>' />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

 **This is the row binding event**

protected void grd_item_list_RowCommand(object sender, GridViewCommandEventArgs e) {

    item_list_bind_structure();

    if (ViewState["item_list"] != null)
        dt = (DataTable)ViewState["item_list"];


    if (e.CommandName == "REMOVE_ITEM") {
        var RowNum = Convert.ToInt32(e.CommandArgument.ToString()) - 1;

        DataRow dr = dt.Rows[RowNum];
        dr.Delete();

    }

    grd_item_list.DataSource = dt;
    grd_item_list.DataBind();
}

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

Everyone is right: stick with POST for non-idempotent requests.

What about using both an URI query string and request content? Well it's valid HTTP (see note 1), so why not?!

It is also perfectly logical: URLs, including their query string part, are for locating resources. Whereas HTTP method verbs (POST - and its optional request content) are for specifying actions, or what to do with resources. Those should be orthogonal concerns. (But, they are not beautifully orthogonal concerns for the special case of ContentType=application/x-www-form-urlencoded, see note 2 below.)

Note 1: HTTP specification (1.1) does not state that query parameters and content are mutually exclusive for a HTTP server that accepts POST or PUT requests. So any server is free to accept both. I.e. if you write the server there's nothing to stop you choosing to accept both (except maybe an inflexible framework). Generally, the server can interpret query strings according to whatever rules it wants. It can even interpret them with conditional logic that refers to other headers like Content-Type too, which leads to Note 2:

Note 2: if a web browser is the primary way people are accessing your web application, and application/x-www-form-urlencoded is the Content-Type they are posting, then you should follow the rules for that Content-Type. And the rules for application/x-www-form-urlencoded are much more specific (and frankly, unusual): in this case you must interpret the URI as a set of parameters, and not a resource location. [This is the same point of usefulness Powerlord raised; that it may be hard to use web forms to POST content to your server. Just explained a little differently.]

Note 3: what are query strings originally for? RFC 3986 defines HTTP query strings as an URI part that works as a non-hierarchical way of locating a resource.

In case readers asking this question wish to ask what is good RESTful architecture: the RESTful architecture pattern doesn't require URI schemes to work a specific way. RESTful architecture concerns itself with other properties of the system, like cacheability of resources, the design of the resources themselves (their behavior, capabilities, and representations), and whether idempotence is satisfied. Or in other words, achieving a design which is highly compatible with HTTP protocol and its set of HTTP method verbs. :-) (In other words, RESTful architecture is not very presciptive with how the resources are located.)

Final note: sometimes query parameters get used for yet other things, which are neither locating resources nor encoding content. Ever seen a query parameter like 'PUT=true' or 'POST=true'? These are workarounds for browsers that don't allow you to use PUT and POST methods. While such parameters are seen as part of the URL query string (on the wire), I argue that they are not part of the URL's query in spirit.

How to change background Opacity when bootstrap modal is open

You can download a custom compiled bootstrap 3, just customize the @modal-backdrop-opacity from:

https://getbootstrap.com/docs/3.4/customize/

Customizing bootstrap 4 requires compiling from source, overriding $modal-backdrop-bg as described in:

https://getbootstrap.com/docs/4.4/getting-started/theming/

In the answers to Bootstrap 4 custom build generator / download there is a NodeJS workflow for compiling Bootstrap 4 from source, alone with some non-official Bootstrap 4 customizers.

Thread pooling in C++11

This is copied from my answer to another very similar post, hope it can help:

1) Start with maximum number of threads a system can support:

int Num_Threads =  thread::hardware_concurrency();

2) For an efficient threadpool implementation, once threads are created according to Num_Threads, it's better not to create new ones, or destroy old ones (by joining). There will be performance penalty, might even make your application goes slower than the serial version.

Each C++11 thread should be running in their function with an infinite loop, constantly waiting for new tasks to grab and run.

Here is how to attach such function to the thread pool:

int Num_Threads = thread::hardware_concurrency();
vector<thread> Pool;
for(int ii = 0; ii < Num_Threads; ii++)
{  Pool.push_back(thread(Infinite_loop_function));}

3) The Infinite_loop_function

This is a "while(true)" loop waiting for the task queue

void The_Pool:: Infinite_loop_function()
{
    while(true)
    {
        {
            unique_lock<mutex> lock(Queue_Mutex);

            condition.wait(lock, []{return !Queue.empty() || terminate_pool});
            Job = Queue.front();
            Queue.pop();
        }
        Job(); // function<void()> type
    }
};

4) Make a function to add job to your Queue

void The_Pool:: Add_Job(function<void()> New_Job)
{
    {
        unique_lock<mutex> lock(Queue_Mutex);
        Queue.push(New_Job);
    }
    condition.notify_one();
}

5) Bind an arbitrary function to your Queue

Pool_Obj.Add_Job(std::bind(&Some_Class::Some_Method, &Some_object));

Once you integrate these ingredients, you have your own dynamic threading pool. These threads always run, waiting for job to do.

I apologize if there are some syntax errors, I typed these code and and I have a bad memory. Sorry that I cannot provide you the complete thread pool code, that would violate my job integrity.

Edit: to terminate the pool, call the shutdown() method:

XXXX::shutdown(){
{
    unique_lock<mutex> lock(threadpool_mutex);
    terminate_pool = true;} // use this flag in condition.wait

    condition.notify_all(); // wake up all threads.

    // Join all threads.
    for(std::thread &every_thread : thread_vector)
    {   every_thread.join();}

    thread_vector.clear();  
    stopped = true; // use this flag in destructor, if not set, call shutdown() 
}

"Cannot open include file: 'config-win.h': No such file or directory" while installing mysql-python

Download the version of Connector from https://dev.mysql.com/downloads/connector/c/6.0.html For my case I had installed 64 bit of connector and my python was 32 bit. So I had to copy MySQL from program files to Program Files(86)

What is the difference between String and StringBuffer in Java?

String is used to manipulate character strings that cannot be changed (read-only and immutable).

StringBuffer is used to represent characters that can be modified.

Performance wise, StringBuffer is faster when performing concatenations. This is because when you concatenate a String, you are creating a new object (internally) every time since String is immutable.

You can also use StringBuilder which is similar to StringBuffer except it is not synchronized. The maximum size for either of these is Integer.MAX_VALUE (231 - 1 = 2,147,483,647) or maximum heap size divided by 2 (see How many characters can a Java String have?). More information here.

clear form values after submission ajax

Simply

$('#cform')[0].reset();

Visual Studio SignTool.exe Not Found

I had the same issue but installing the Windows 8.1 SDK as per Catquatwa's answer did not work for me (signtool.exe was still missing from C:\Program Files (x86)\Microsoft SDKs\Windows\vX\Bin).

I stumbled across this solution: http://www.benedykt.net/2015/08/12/missing-signtool-exe-w-visual-studio-2015/

Basically, for VS 2015, this would be:

  • Open Programs and Features
  • Select "Microsoft Visual Studio 2015" and click "Change"
  • Press "Modify" to progress to Features options
  • Select "Windows and Web Development", then tick "ClickOnce Publishing Tools" for installation
  • Then "Next" and then "Update"

In C/C++ what's the simplest way to reverse the order of bits in a byte?

Assuming that your compiler allows unsigned long long:

unsigned char reverse(unsigned char b) {
  return (b * 0x0202020202ULL & 0x010884422010ULL) % 1023;
}

Discovered here

What is the yield keyword used for in C#?

Iteration. It creates a state machine "under the covers" that remembers where you were on each additional cycle of the function and picks up from there.

Can I bind an array to an IN() condition?

For something quick:

//$db = new PDO(...);
//$ids = array(...);

$qMarks = str_repeat('?,', count($ids) - 1) . '?';
$sth = $db->prepare("SELECT * FROM myTable WHERE id IN ($qMarks)");
$sth->execute($ids);

Base 64 encode and decode example code

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".BaseActivity">
   <EditText
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:id="@+id/edt"
       android:paddingTop="30dp"
       />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv1"
        android:text="Encode"
        android:textSize="20dp"
        android:padding="20dp"
        />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv2"

        android:textSize="20dp"
        android:padding="20dp"
        />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv3"
        android:text="decode"
        android:textSize="20dp"
        android:padding="20dp"
        />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv4"
        android:textSize="20dp"
        android:padding="20dp"


        />
</LinearLayout>

Interview Question: Merge two sorted singly linked lists without creating new nodes

        /* Simple/Elegant Iterative approach in Java*/    
        private static LinkedList mergeLists(LinkedList list1, LinkedList list2) {
                    Node head1 = list1.start;
                    Node head2 = list2.start;
                    if (list1.size == 0)
                    return list2;
                    if (list2.size == 0)
                    return list1;               
                    LinkedList mergeList = new LinkedList();
                    while (head1 != null && head2 != null) {
                        if (head1.getData() < head2.getData()) {
                            int data = head1.getData();
                            mergeList.insert(data);
                            head1 = head1.getNext();
                        } else {
                            int data = head2.getData();
                            mergeList.insert(data);
                            head2 = head2.getNext();
                        }
                    }
                    while (head1 != null) {
                        int data = head1.getData();
                        mergeList.insert(data);
                        head1 = head1.getNext();
                    }
                    while (head2 != null) {
                        int data = head2.getData();
                        mergeList.insert(data);
                        head2 = head2.getNext();
                    }
                    return mergeList;
                }

/* Build-In singly LinkedList class in Java*/
class LinkedList {
    Node start;
    int size = 0;

    void insert(int data) {
        if (start == null)
            start = new Node(data);
        else {
            Node temp = start;
            while (temp.getNext() != null) {
                temp = temp.getNext();
            }
            temp.setNext(new Node(data));
        }
        size++;
    }

    @Override
    public String toString() {

        String str = "";
        Node temp=start;
        while (temp != null) {
            str += temp.getData() + "-->";
            temp = temp.getNext();
        }
        return str;
    }

}

Convert hex to binary

I added the calculation for the number of bits to fill to Onedinkenedi's solution. Here is the resulting function:

def hextobin(h):
  return bin(int(h, 16))[2:].zfill(len(h) * 4)

Where 16 is the base you're converting from (hexadecimal), and 4 is how many bits you need to represent each digit, or log base 2 of the scale.

Simulator or Emulator? What is the difference?

Simple Explanation.

If you want to convert your PC (running Windows) into Mac, you can do either of these:

(1) You can simply install a Mac theme on your Windows. So, your PC feels more like Mac, but you can't actually run any Mac programs. (SIMULATION)

(or)

(2) You can program your PC to run like Mac (I'm not sure if this is possible :P ). Now you can even run Mac programs successfully and expect the same output as on Mac. (EMULATION)

In the first case, you can experience Mac, but you can't expect the same output as on Mac.
In the second case, you can expect the same output as on Mac, but still the fact remains that it is only a PC.

How can I make setInterval also work when a tab is inactive in Chrome?

Playing an audio file ensures full background Javascript performance for the time being

For me, it was the simplest and least intrusive solution - apart from playing a faint / almost-empty sound, there are no other potential side effects

You can find the details here: https://stackoverflow.com/a/51191818/914546

(From other answers, I see that some people use different properties of the Audio tag, I do wonder whether it's possible to use the Audio tag for full performance, without actually playing something)

DTO pattern: Best way to copy properties between two objects

Wouldn't lambdaj's project function do what you are looking for?

It'll look something like this:

List<UserDTO> userNDtos = project(users, UserDTO.class, on(User.class).getUserName(), on(User.class).getFullName(), .....);

(Define the constructor for UserDTO accordingly...)

Also see here for examples...

How to disable Compatibility View in IE

All you need is to force disable C.M. in IE - Just paste This code (in IE9 and under c.m. will be disabled):

<meta http-equiv="X-UA-Compatible" content="IE=9; IE=8; IE=7; IE=EDGE" />

Source: http://twigstechtips.blogspot.com/2010/03/css-ie8-meta-tag-to-disable.html

How to set JVM parameters for Junit Unit Tests?

If you set it in Java code, you can set it like this

      static {
        System.getProperties().setProperty("env", "test");
        System.getProperties().setProperty("spring.application.name", "spring-example");
    }

reference:

https://stackoverflow.com/a/60654275/4712855

https://stackoverflow.com/a/10774432/4712855

Int or Number DataType for DataAnnotation validation attribute

You can write a custom validation attribute:

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter, AllowMultiple = false)]
public class Numeric : ValidationAttribute
{
    public Numeric(string errorMessage) : base(errorMessage)
    {
    }

    /// <summary>
    /// Check if given value is numeric
    /// </summary>
    /// <param name="value">The input value</param>
    /// <returns>True if value is numeric</returns>
    public override bool IsValid(object value)
    {
        return decimal.TryParse(value?.ToString(), out _);
    }
}

On your property you can then use the following annotation:

[Numeric("Please fill in a valid number.")]
public int NumberOfBooks { get; set; }

Mysql - How to quit/exit from stored procedure

This works for me :

 CREATE DEFINER=`root`@`%` PROCEDURE `save_package_as_template`( IN package_id int , 
IN bus_fun_temp_id int  , OUT o_message VARCHAR (50) ,
            OUT o_number INT )
 BEGIN

DECLARE  v_pkg_name  varchar(50) ;

DECLARE  v_pkg_temp_id  int(10)  ; 

DECLARE  v_workflow_count INT(10);

-- checking if workflow created for package
select count(*)  INTO v_workflow_count from workflow w where w.package_id = 
package_id ;

this_proc:BEGIN   -- this_proc block start here 

 IF  v_workflow_count = 0 THEN
   select 'no work flow ' as 'workflow_status' ;
    SET o_message ='Work flow is not created for this package.';
    SET  o_number = -2 ;
      LEAVE this_proc;
 END IF;

select 'work flow  created ' as 'workflow_status' ;
-- To  send some message
SET o_message ='SUCCESSFUL';
SET  o_number = 1 ;

  END ;-- this_proc block end here 

END

What is the equivalent of Java's final in C#?

What everyone here is missing is Java's guarantee of definite assignment for final member variables.

For a class C with final member variable V, every possible execution path through every constructor of C must assign V exactly once - failing to assign V or assigning V two or more times will result in an error.

C#'s readonly keyword has no such guarantee - the compiler is more than happy to leave readonly members unassigned or allow you to assign them multiple times within a constructor.

So, final and readonly (at least with respect to member variables) are definitely not equivalent - final is much more strict.

How Best to Compare Two Collections in Java and Act on Them?

For comaparing a list or set we can use Arrays.equals(object[], object[]). It will check for the values only. To get the Object[] we can use Collection.toArray() method.

How to tell which commit a tag points to in Git?

Even though this is pretty old, I thought I would point out a cool feature I just found for listing tags with commits:

git log --decorate=full

It will show the branches which end/start at a commit, and the tags for commits.

MVC3 DropDownListFor - a simple example?

You should do like this:

@Html.DropDownListFor(m => m.ContribType, 
                new SelectList(Model.ContribTypeOptions, 
                               "ContribId", "Value"))

Where:

m => m.ContribType

is a property where the result value will be.

text-align:center won't work with form <label> tag (?)

label is an inline element so its width is equal to the width of the text it contains. The browser is actually displaying the label with text-align:center but since the label is only as wide as the text you don't notice.

The best thing to do is to apply a specific width to the label that is greater than the width of the content - this will give you the results you want.

Insert if not exists Oracle

If you do NOT want to merge in from an other table, but rather insert new data... I came up with this. Is there perhaps a better way to do this?

MERGE INTO TABLE1 a
    USING DUAL
    ON (a.C1_pk= 6)
WHEN NOT MATCHED THEN
    INSERT(C1_pk, C2,C3,C4)
    VALUES (6, 1,0,1);

How to use HTTP GET in PowerShell?

In PowerShell v3, have a look at the Invoke-WebRequest and Invoke-RestMethod e.g.:

$msg = Read-Host -Prompt "Enter message"
$encmsg = [System.Web.HttpUtility]::UrlEncode($msg)
Invoke-WebRequest -Uri "http://smsserver/SNSManager/msgSend.jsp?uid&to=smartsms:*+001XXXXXX&msg=$encmsg&encoding=windows-1255"

HTML meta tag for content language

another language meta tag is og:locale and you can define og:locale meta tag for social media

<meta property="og:locale" content="en" />

How to reload the current route with the angular 2 router

Angular 2-4 route reload hack

For me, using this method inside a root component (component, which is present on any route) works:

onRefresh() {
  this.router.routeReuseStrategy.shouldReuseRoute = function(){return false;};

  let currentUrl = this.router.url + '?';

  this.router.navigateByUrl(currentUrl)
    .then(() => {
      this.router.navigated = false;
      this.router.navigate([this.router.url]);
    });
  }

Selenium and xPath - locating a link by containing text

Use this

//*[@id='popover-search']/div/div/ul/li[1]/a/span[contains(text(),'Some text')]

OR

//*[@id='popover-search']/div/div/ul/li[1]/a/span[contains(.,'Some text')]

Cause of a process being a deadlock victim

The answers here are worth a try, but you should also review your code. Specifically have a read of Polyfun's answer here: How to get rid of deadlock in a SQL Server 2005 and C# application?

It explains the concurrency issue, and how the usage of "with (updlock)" in your queries might correct your deadlock situation - depending really on exactly what your code is doing. If your code does follow this pattern, this is likely a better fix to make, before resorting to dirty reads, etc.

#1130 - Host ‘localhost’ is not allowed to connect to this MySQL server

Find the file "config.inc.php" under your phpMyAdmin directory and edit the following lines:

$cfg['Servers'][$i]['auth_type'] = 'config'; // config, http, cookie

$cfg['Servers'][$i]['user'] = 'root'; // MySQL user

$cfg['Servers'][$i]['password'] = 'TYPE_YOUR_PASSWORD_HERE'; // MySQL password

Note that the password used in the 'password' field must be the same for the MySQL root password. Also, you should check if root login is allowed in this line:

$cfg['Servers'][$i]['AllowRoot']     = TRUE;        // true = allow root login

This way you have your root password set.

[Ljava.lang.Object; cannot be cast to

In case entire entity is being return, better solution in spring JPA is use @Query(value = "from entity where Id in :ids")

This return entity type rather than object type

ProgressDialog is deprecated.What is the alternate one to use?

ProgressBar is very simple and easy to use, i am intending to make this same as simple progress dialog. first step is that you can make xml layout of the dialog that you want to show, let say we name this layout

layout_loading_dialog.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="20dp">
    <ProgressBar
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1" />

    <TextView
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="4"
        android:gravity="center"
        android:text="Please wait! This may take a moment." />
</LinearLayout>

next step is create AlertDialog which will show this layout with ProgressBar

AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setCancelable(false); // if you want user to wait for some process to finish,
builder.setView(R.layout.layout_loading_dialog);
AlertDialog dialog = builder.create();

now all that is left is to show and hide this dialog in our click events like this

dialog.show(); // to show this dialog
dialog.dismiss(); // to hide this dialog

and thats it, it should work, as you can see it is farely simple and easy to implement ProgressBar instead of ProgressDialog. now you can show/dismiss this dialog box in either Handler or ASyncTask, its up to your need

Flutter does not find android sdk

I solved this problem by below step,

1) go to -> system environment -> Environment Variables -> system Variable

2) create New Variable Name ANDROID_HOME and Value D:\Androidsdk\tools (custom android sdk path).

3) concat this path D:\Androidsdk\platform-tools in Path variable value using ";". (also in system Variable)

4) that's all, Restart the PC to apply changes and try again -- flutter Doctor.

Catching exceptions from Guzzle

I want to update the answer for exception handling in Psr-7 Guzzle, Guzzle7 and HTTPClient(expressive, minimal API around the Guzzle HTTP client provided by laravel).

Guzzle7 (same works for Guzzle 6 as well)

Using RequestException, RequestException catches any exception that can be thrown while transferring requests.

try{
  $client = new \GuzzleHttp\Client(['headers' => ['Authorization' => 'Bearer ' . $token]]);
  
  $guzzleResponse = $client->get('/foobar');
  // or can use
  // $guzzleResponse = $client->request('GET', '/foobar')
    if ($guzzleResponse->getStatusCode() == 200) {
         $response = json_decode($guzzleResponse->getBody(),true);
         //perform your action with $response 
    } 
}
catch(\GuzzleHttp\Exception\RequestException $e){
   // you can catch here 400 response errors and 500 response errors
   // You can either use logs here use Illuminate\Support\Facades\Log;
   $error['error'] = $e->getMessage();
   $error['request'] = $e->getRequest();
   if($e->hasResponse()){
       if ($e->getResponse()->getStatusCode() == '400'){
           $error['response'] = $e->getResponse(); 
       }
   }
   Log::error('Error occurred in get request.', ['error' => $error]);
}catch(Exception $e){
   //other errors 
}

Psr7 Guzzle

use GuzzleHttp\Psr7;
use GuzzleHttp\Exception\RequestException;

try {
    $client->request('GET', '/foo');
} catch (RequestException $e) {
    $error['error'] = $e->getMessage();
    $error['request'] = Psr7\Message::toString($e->getRequest());
    if ($e->hasResponse()) {
        $error['response'] = Psr7\Message::toString($e->getResponse());
    }
    Log::error('Error occurred in get request.', ['error' => $error]);
}

For HTTPClient

use Illuminate\Support\Facades\Http;
try{
    $response = Http::get('http://api.foo.com');
    if($response->successful()){
        $reply = $response->json();
    }
    if($response->failed()){
        if($response->clientError()){
            //catch all 400 exceptions
            Log::debug('client Error occurred in get request.');
            $response->throw();
        }
        if($response->serverError()){
            //catch all 500 exceptions
            Log::debug('server Error occurred in get request.');
            $response->throw();
        }
        
    }
 }catch(Exception $e){
     //catch the exception here
 }

How to retrieve the first word of the output of a command in bash?

echo "word1 word2 word3" | { read first rest ; echo $first ; }

This has the advantage that is not using external commands and leaves the $1, $2, etc. variables intact.

How to exit an Android app programmatically?

Intent homeIntent = new Intent(Intent.ACTION_MAIN);
homeIntent.addCategory( Intent.CATEGORY_HOME );
homeIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(homeIntent);
System.exit(1);

Use this Code it's much useful, and you can exit all of the activities.

Bootstrap 4 - Glyphicons migration?

If you are using Laravel 5.6, it comes with Bootstrap 4. All you need to is:

npm install and npm install open-iconic --save

At /resources/assets/sass/app.scss change the line of of Google font import on line 2 to

@import '~open-iconic/font/css/open-iconic-bootstrap';

All you need to do now is

npm run watch

and include

<link rel="stylesheet" href="{{asset('css/app.css')}}">

on top of master blade file and <script src="{{asset('js/app.js')}}"></script> before closing body tag. You will get Bootstrap 4 and icon.

Usage is <span class="oi oi-cog"></span>

Refer here for icon details: Open Iconic: Recommended by Bootstrap 4

If on other project than Laravel, you can just do import @import 'node_modules/open-iconic/font/css/open-iconic-bootstrap-min.css'; in your style file.

Hope this helps. Happy trying.

.gitignore is ignored by Git

One tricky thing not covered by the other answers here is that the .gitignore file won't work if you have inline comments, like this:

foo/bar # The bar file contains sensitive data so we don't want to make this public

So, if you do have comments like that, change them like this:

# The bar file contains sensitive data so we don't want to make this public
foo/bar

The located assembly's manifest definition does not match the assembly reference

I had a similar problem when attempting to update one DLL file of my web-site.

This error was occurring, when I simply copied this DLL file into bin folder over FTP.

I resolved this problem by:

  1. stopping the web-site;
  2. copying needed DLL file/DLL files;
  3. starting the web-site

if (select count(column) from table) > 0 then

not so elegant but you dont need to declare any variable:

for k in (select max(1) from table where 1 = 1) loop
    update x where column = value;
end loop;

Can I hide the HTML5 number input’s spin box?

I needed this to work

/* Chrome, Safari, Edge, Opera */
input[type=number]::-webkit-outer-spin-button,
input[type=number]::-webkit-inner-spin-button
  -webkit-appearance: none
  appearance: none
  margin: 0

/* Firefox */
input[type=number]
  -moz-appearance: textfield

The extra line of appearance: none was key to me.

Import Script from a Parent Directory

If you want to run the script directly, you can:

  1. Add the FolderA's path to the environment variable (PYTHONPATH).
  2. Add the path to sys.path in the your script.

Then:

import module_you_wanted

Passing arrays as parameters in bash

function aecho {
  set "$1[$2]"
  echo "${!1}"
}

Example

$ foo=(dog cat bird)

$ aecho foo 1
cat

ssh_exchange_identification: Connection closed by remote host under Git bash

Simple server reboot solved the problem for me. Try hard reboot , if dont work after soft reboot.

Using sed, how do you print the first 'N' characters of a line?

To print the N first characters you can remove the N+1 characters up to the end of line:

$ sed 's/.//5g' <<< "defn-test"
defn

How can I convert a hex string to a byte array?

Here's a nice fun LINQ example.

public static byte[] StringToByteArray(string hex) {
    return Enumerable.Range(0, hex.Length)
                     .Where(x => x % 2 == 0)
                     .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
                     .ToArray();
}

Installing SQL Server 2012 - Error: Prior Visual Studio 2010 instances requiring update

I did everything provided in the previous answers to this question, but still had the issue. I did have the update installed, but I ran the installer again, reapplying the update while SQL 2012 Installer was open on the screen where I could run the check again. After it finished, I ran the check again and it passed.

Android: android.content.res.Resources$NotFoundException: String resource ID #0x5

Using DataBinding and setting background to the edittext with resources from the drawable folder causes the exception.

<EditText
                            android:background="@drawable/rectangle"
                            android:imeOptions="flagNoExtractUi"
                            android:layout_width="match_parent"
                            android:layout_height="45dp"
                            android:hint="Enter Your Name"
                            android:gravity="center"
                            android:textColorHint="@color/hintColor"
                            android:singleLine="true"
                            android:id="@+id/etName"
                            android:inputType="textCapWords"
                            android:text="@={viewModel.model.name}"
                            android:fontFamily="@font/avenir_roman"/>

Solution

I just change the background from android:background="@drawable/rectangle" to android:background="@null"

Clean and Rebuild the Project.

Spring Boot War deployed to Tomcat

Update 2018-02-03 with Spring Boot 1.5.8.RELEASE.

In pom.xml, you need to tell Spring plugin when it is building that it is a war file by change package to war, like this:

<packaging>war</packaging>

Also, you have to excluded the embedded tomcat while building the package by adding this:

    <!-- to deploy as a war in tomcat -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <scope>provided</scope>
    </dependency>

The full runable example is in here https://www.surasint.com/spring-boot-create-war-for-tomcat/

Named parameters in JDBC

JDBC does not support named parameters. Unless you are bound to using plain JDBC (which causes pain, let me tell you that) I would suggest to use Springs Excellent JDBCTemplate which can be used without the whole IoC Container.

NamedParameterJDBCTemplate supports named parameters, you can use them like that:

 NamedParameterJdbcTemplate jdbcTemplate = new NamedParameterJdbcTemplate(dataSource);

 MapSqlParameterSource paramSource = new MapSqlParameterSource();
 paramSource.addValue("name", name);
 paramSource.addValue("city", city);
 jdbcTemplate.queryForRowSet("SELECT * FROM customers WHERE name = :name AND city = :city", paramSource);

How to create a self-signed certificate for a domain name for development?

Using PowerShell

From Windows 8.1 and Windows Server 2012 R2 (Windows PowerShell 4.0) and upwards, you can create a self-signed certificate using the new New-SelfSignedCertificate cmdlet:

Examples:

New-SelfSignedCertificate -DnsName www.mydomain.com -CertStoreLocation cert:\LocalMachine\My

New-SelfSignedCertificate -DnsName subdomain.mydomain.com -CertStoreLocation cert:\LocalMachine\My

New-SelfSignedCertificate -DnsName *.mydomain.com -CertStoreLocation cert:\LocalMachine\My

Using the IIS Manager

  1. Launch the IIS Manager
  2. At the server level, under IIS, select Server Certificates
  3. On the right hand side under Actions select Create Self-Signed Certificate
  4. Where it says "Specify a friendly name for the certificate" type in an appropriate name for reference.
    1. Examples: www.domain.com or subdomain.domain.com
  5. Then, select your website from the list on the left hand side
  6. On the right hand side under Actions select Bindings
  7. Add a new HTTPS binding and select the certificate you just created (if your certificate is a wildcard certificate you'll need to specify a hostname)
  8. Click OK and test it out.

How to set breakpoints in inline Javascript in Google Chrome?

This is an extension of Rian Schmits' answer above. In my case, I had HTML code embedded in my JavaScript code and I couldn't see anything other than the HTML code. Maybe Chrome Debugging has changed over the years but right-clicking the Sources/Sources tab presented me with Add folder to workspace. I was able to add my entire project, which gave me access to all of my JavaScripts. You can find more detail in this link. I hope this helps somebody.

Start index for iterating Python list

You can use slicing:

for item in some_list[2:]:
    # do stuff

This will start at the third element and iterate to the end.