Programs & Examples On #History

DO NOT USE THIS TAG. Questions about the history of programming are off-topic. For questions about browser history, use [browser-history] instead. For questions about the JavaScript library, use [history.js]. For questions about the HTML5 API, use [html5-history]. For questions about version control, use [revision-history]. For questions about recalling inputs in an entry box, use [input-history].

nginx: send all requests to a single html page

I think this will do it for you:

location / {
    try_files /base.html =404;
}

Original purpose of <input type="hidden">?

I'll provide a simple Server Side Real World Example here, say if the records are looped and each record has a form with a delete button and you need to delete a specific record, so here comes the hidden field in action, else you won't get the reference of the record to be deleted in this case, it will be id

For example

<?php
    if(isset($_POST['delete_action'])) {
        mysqli_query($connection, "DELETE FROM table_name 
                                   WHERE record_id = ".$_POST['row_to_be_deleted']);
                                   //Here is where hidden field value is used
    }

    while(condition) {
?>
    <span><?php echo 'Looped Record Name'; ?>
    <form method="post">
        <input type="hidden" name="row_to_be_deleted" value="<?php echo $record_id; ?>" />
        <input type="submit" name="delete_action" />
    </form>
<?php
    }
?>

SecurityError: The operation is insecure - window.history.pushState()

You should try not open the file with a folder-explorer method (i.e. file://), but open that file from http:// (i.e. http://yoursite.com/ from http://localhost/)

Linux Command History with date and time

In case you are using zsh you can use for example the -E or -i switch:

history -E

If you do a man zshoptions or man zshbuiltins you can find out more information about these switches as well as other info related to history:

Also when listing,
 -d     prints timestamps for each event
 -f     prints full time-date stamps in the US `MM/DD/YY hh:mm' format
 -E     prints full time-date stamps in the European `dd.mm.yyyy hh:mm' format
 -i     prints full time-date stamps in ISO8601 `yyyy-mm-dd hh:mm' format
 -t fmt prints time and date stamps in the given format; fmt is formatted with the strftime function with the zsh extensions  described  for  the  %D{string} prompt format in the section EXPANSION OF PROMPT SEQUENCES in zshmisc(1).  The resulting formatted string must be no more than 256 characters or will not be printed
 -D     prints elapsed times; may be combined with one of the options above

What is the origin of foo and bar?

tl;dr

  • "Foo" and "bar" as metasyntactic variables were popularised by MIT and DEC, the first references are in work on LISP and PDP-1 and Project MAC from 1964 onwards.

  • Many of these people were in MIT's Tech Model Railroad Club, where we find the first documented use of "foo" in tech circles in 1959 (and a variant in 1958).

  • Both "foo" and "bar" (and even "baz") were well known in popular culture, especially from Smokey Stover and Pogo comics, which will have been read by many TMRC members.

  • Also, it seems likely the military FUBAR contributed to their popularity.


The use of lone "foo" as a nonsense word is pretty well documented in popular culture in the early 20th century, as is the military FUBAR. (Some background reading: FOLDOC FOLDOC Jargon File Jargon File Wikipedia RFC3092)


OK, so let's find some references.

STOP PRESS! After posting this answer, I discovered this perfect article about "foo" in the Friday 14th January 1938 edition of The Tech ("MIT's oldest and largest newspaper & the first newspaper published on the web"), Volume LVII. No. 57, Price Three Cents:

On Foo-ism

The Lounger thinks that this business of Foo-ism has been carried too far by its misguided proponents, and does hereby and forthwith take his stand against its abuse. It may be that there's no foo like an old foo, and we're it, but anyway, a foo and his money are some party. (Voice from the bleachers- "Don't be foo-lish!")

As an expletive, of course, "foo!" has a definite and probably irreplaceable position in our language, although we fear that the excessive use to which it is currently subjected may well result in its falling into an early (and, alas, a dark) oblivion. We say alas because proper use of the word may result in such happy incidents as the following.

It was an 8.50 Thermodynamics lecture by Professor Slater in Room 6-120. The professor, having covered the front side of the blackboard, set the handle that operates the lift mechanism, turning meanwhile to the class to continue his discussion. The front board slowly, majestically, lifted itself, revealing the board behind it, and on that board, writ large, the symbols that spelled "FOO"!

The Tech newspaper, a year earlier, the Letter to the Editor, September 1937:

By the time the train has reached the station the neophytes are so filled with the stories of the glory of Phi Omicron Omicron, usually referred to as Foo, that they are easy prey.

...

It is not that I mind having lost my first four sons to the Grand and Universal Brotherhood of Phi Omicron Omicron, but I do wish that my fifth son, my baby, should at least be warned in advance.

Hopefully yours,

Indignant Mother of Five.

And The Tech in December 1938:

General trend of thought might be best interpreted from the remarks made at the end of the ballots. One vote said, '"I don't think what I do is any of Pulver's business," while another merely added a curt "Foo."


The first documented "foo" in tech circles is probably 1959's Dictionary of the TMRC Language:

FOO: the sacred syllable (FOO MANI PADME HUM); to be spoken only when under inspiration to commune with the Deity. Our first obligation is to keep the Foo Counters turning.

These are explained at FOLDOC. The dictionary's compiler Pete Samson said in 2005:

Use of this word at TMRC antedates my coming there. A foo counter could simply have randomly flashing lights, or could be a real counter with an obscure input.

And from 1996's Jargon File 4.0.0:

Earlier versions of this lexicon derived 'baz' as a Stanford corruption of bar. However, Pete Samson (compiler of the TMRC lexicon) reports it was already current when he joined TMRC in 1958. He says "It came from "Pogo". Albert the Alligator, when vexed or outraged, would shout 'Bazz Fazz!' or 'Rowrbazzle!' The club layout was said to model the (mythical) New England counties of Rowrfolk and Bassex (Rowrbazzle mingled with (Norfolk/Suffolk/Middlesex/Essex)."

A year before the TMRC dictionary, 1958's MIT Voo Doo Gazette ("Humor suplement of the MIT Deans' office") (PDF) mentions Foocom, in "The Laws of Murphy and Finagle" by John Banzhaf (an electrical engineering student):

Further research under a joint Foocom and Anarcom grant expanded the law to be all embracing and universally applicable: If anything can go wrong, it will!

Also 1964's MIT Voo Doo (PDF) references the TMRC usage:

Yes! I want to be an instant success and snow customers. Send me a degree in: ...

  • Foo Counters

  • Foo Jung


Let's find "foo", "bar" and "foobar" published in code examples.

So, Jargon File 4.4.7 says of "foobar":

Probably originally propagated through DECsystem manuals by Digital Equipment Corporation (DEC) in 1960s and early 1970s; confirmed sightings there go back to 1972.

The first published reference I can find is from February 1964, but written in June 1963, The Programming Language LISP: its Operation and Applications by Information International, Inc., with many authors, but including Timothy P. Hart and Michael Levin:

Thus, since "FOO" is a name for itself, "COMITRIN" will treat both "FOO" and "(FOO)" in exactly the same way.

Also includes other metasyntactic variables such as: FOO CROCK GLITCH / POOT TOOR / ON YOU / SNAP CRACKLE POP / X Y Z

I expect this is much the same as this next reference of "foo" from MIT's Project MAC in January 1964's AIM-064, or LISP Exercises by Timothy P. Hart and Michael Levin:

car[((FOO . CROCK) . GLITCH)]

It shares many other metasyntactic variables like: CHI / BOSTON NEW YORK / SPINACH BUTTER STEAK / FOO CROCK GLITCH / POOT TOOP / TOOT TOOT / ISTHISATRIVIALEXCERCISE / PLOOP FLOT TOP / SNAP CRACKLE POP / ONE TWO THREE / PLANE SUB THRESHER

For both "foo" and "bar" together, the earliest reference I could find is from MIT's Project MAC in June 1966's AIM-098, or PDP-6 LISP by none other than Peter Samson:

EXPLODE, like PRIN1, inserts slashes, so (EXPLODE (QUOTE FOO/ BAR)) PRIN1's as (F O O // / B A R) or PRINC's as (F O O / B A R).


Some more recallations.

@Walter Mitty recalled on this site in 2008:

I second the jargon file regarding Foo Bar. I can trace it back at least to 1963, and PDP-1 serial number 2, which was on the second floor of Building 26 at MIT. Foo and Foo Bar were used there, and after 1964 at the PDP-6 room at project MAC.

John V. Everett recalls in 1996:

When I joined DEC in 1966, foobar was already being commonly used as a throw-away file name. I believe fubar became foobar because the PDP-6 supported six character names, although I always assumed the term migrated to DEC from MIT. There were many MIT types at DEC in those days, some of whom had worked with the 7090/7094 CTSS. Since the 709x was also a 36 bit machine, foobar may have been used as a common file name there.

Foo and bar were also commonly used as file extensions. Since the text editors of the day operated on an input file and produced an output file, it was common to edit from a .foo file to a .bar file, and back again.

It was also common to use foo to fill a buffer when editing with TECO. The text string to exactly fill one disk block was IFOO$HXA127GA$$. Almost all of the PDP-6/10 programmers I worked with used this same command string.

Daniel P. B. Smith in 1998:

Dick Gruen had a device in his dorm room, the usual assemblage of B-battery, resistors, capacitors, and NE-2 neon tubes, which he called a "foo counter." This would have been circa 1964 or so.

Robert Schuldenfrei in 1996:

The use of FOO and BAR as example variable names goes back at least to 1964 and the IBM 7070. This too may be older, but that is where I first saw it. This was in Assembler. What would be the FORTRAN integer equivalent? IFOO and IBAR?

Paul M. Wexelblat in 1992:

The earliest PDP-1 Assembler used two characters for symbols (18 bit machine) programmers always left a few words as patch space to fix problems. (Jump to patch space, do new code, jump back) That space conventionally was named FU: which stood for Fxxx Up, the place where you fixed Fxxx Ups. When spoken, it was known as FU space. Later Assemblers ( e.g. MIDAS allowed three char tags so FU became FOO, and as ALL PDP-1 programmers will tell you that was FOO space.

Bruce B. Reynolds in 1996:

On the IBM side of FOO(FU)BAR is the use of the BAR side as Base Address Register; in the middle 1970's CICS programmers had to worry out the various xxxBARs...I think one of those was FRACTBAR...

Here's a straight IBM "BAR" from 1955.


Other early references:


I haven't been able to find any references to foo bar as "inverted foo signal" as suggested in RFC3092 and elsewhere.

Here are a some of even earlier F00s but I think they're coincidences/false positives:

Why number 9 in kill -9 command in unix?

I don't think there is any significance to number 9. In addition, despite common believe, kill is used not only to kill processes but also send a signal to a process. If you are really curious you can read here and here.

What is the correct way to restore a deleted file from SVN?

Use the Tortoise SVN copy functionality to revert commited changes:

  1. Right click the parent folder that contains the deleted files/folder
  2. Select the "show log"
  3. Select and right click on the version before which the changes/deleted was done
  4. Select the "browse repository"
  5. Select the file/folder which needs to be restored and right click
  6. Select "copy to" which will copy the files/folders to the head revision

Hope that helps

How to install python3 version of package via pip on Ubuntu?

Ubuntu 12.10+ and Fedora 13+ have a package called python3-pip which will install pip-3.2 (or pip-3.3, pip-3.4 or pip3 for newer versions) without needing this jumping through hoops.


I came across this and fixed this without needing the likes of wget or virtualenvs (assuming Ubuntu 12.04):

  1. Install package python3-setuptools: run sudo aptitude install python3-setuptools, this will give you the command easy_install3.
  2. Install pip using Python 3's setuptools: run sudo easy_install3 pip, this will give you the command pip-3.2 like kev's solution.
  3. Install your PyPI packages: run sudo pip-3.2 install <package> (installing python packages into your base system requires root, of course).
  4. Profit!

Get File Path (ends with folder)

In the VBA Editor's Tools menu, click References... scroll down to "Microsoft Shell Controls And Automation" and choose it.

Sub FolderSelection()
    Dim MyPath As String
    MyPath = SelectFolder("Select Folder", "")
    If Len(MyPath) Then
        MsgBox MyPath
    Else
        MsgBox "Cancel was pressed"
    End If
End Sub

'Both arguements are optional. The first is the dialog caption and
'the second is is to specify the top-most visible folder in the
'hierarchy. The default is "My Computer."

Function SelectFolder(Optional Title As String, Optional TopFolder _
                         As String) As String
    Dim objShell As New Shell32.Shell
    Dim objFolder As Shell32.Folder

'If you use 16384 instead of 1 on the next line,
'files are also displayed
    Set objFolder = objShell.BrowseForFolder _
                            (0, Title, 1, TopFolder)
    If Not objFolder Is Nothing Then
        SelectFolder = objFolder.Items.Item.Path
    End If
End Function

Source Link.

Symfony 2 EntityManager injection in service

Since 2017 and Symfony 3.3 you can register Repository as service, with all its advantages it has.

Check my post How to use Repository with Doctrine as Service in Symfony for more general description.


To your specific case, original code with tuning would look like this:

1. Use in your services or Controller

<?php

namespace Test\CommonBundle\Services;

use Doctrine\ORM\EntityManagerInterface;

class UserService
{
    private $userRepository;

    // use custom repository over direct use of EntityManager
    // see step 2
    public function __constructor(UserRepository $userRepository)
    {
        $this->userRepository = $userRepository;
    }

    public function getUser($userId)
    {
        return $this->userRepository->find($userId);
    }
}

2. Create new custom repository

<?php

namespace Test\CommonBundle\Repository;

use Doctrine\ORM\EntityManagerInterface;

class UserRepository
{
    private $repository;

    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->repository = $entityManager->getRepository(UserEntity::class);
    }

    public function find($userId)
    {
        return  $this->repository->find($userId);
    }
}

3. Register services

# app/config/services.yml
services:
    _defaults:
        autowire: true

    Test\CommonBundle\:
       resource: ../../Test/CommonBundle

Is a Python list guaranteed to have its elements stay in the order they are inserted in?

I suppose one thing that may be concerning you is whether or not the entries could change, so that the 2 becomes a different number, for instance. You can put your mind at ease here, because in Python, integers are immutable, meaning they cannot change after they are created.

Not everything in Python is immutable, though. For example, lists are mutable---they can change after being created. So for example, if you had a list of lists

>>> a = [[1], [2], [3]]
>>> a[0].append(7)
>>> a
[[1, 7], [2], [3]]

Here, I changed the first entry of a (I added 7 to it). One could imagine shuffling things around, and getting unexpected things here if you are not careful (and indeed, this does happen to everyone when they start programming in Python in some way or another; just search this site for "modifying a list while looping through it" to see dozens of examples).

It's also worth pointing out that x = x + [a] and x.append(a) are not the same thing. The second one mutates x, and the first one creates a new list and assigns it to x. To see the difference, try setting y = x before adding anything to x and trying each one, and look at the difference the two make to y.

How can I set my Cygwin PATH to find javac?

as you write the it with double-quotes, you don't need to escape spaces with \

export PATH=$PATH:"/cygdrive/C/Program Files/Java/jdk1.6.0_23/bin/"

of course this also works:

export PATH=$PATH:/cygdrive/C/Program\ Files/Java/jdk1.6.0_23/bin/

Is it possible to convert char[] to char* in C?

If you have char[] c then you can do char* d = &c[0] and access element c[1] by doing *(d+1), etc.

How can I submit a form using JavaScript?

If your form does not have any id, but it has a class name like theForm, you can use the below statement to submit it:

document.getElementsByClassName("theForm")[0].submit();

.net Core 2.0 - Package was restored using .NetFramework 4.6.1 instead of target framework .netCore 2.0. The package may not be fully compatible

The package is not fully compatible with dotnetcore 2.0 for now.

eg, for 'Microsoft.AspNet.WebApi.Client' it maybe supported in version (5.2.4). See Consume new Microsoft.AspNet.WebApi.Client.5.2.4 package for details.

You could try the standard Client package as Federico mentioned.

If that still not work, then as a workaround you can only create a Console App (.Net Framework) instead of the .net core 2.0 console app.

Reference this thread: Microsoft.AspNet.WebApi.Client supported in .NET Core or not?

Find files and tar them (with spaces)

If you have multiple files or directories and you want to zip them into independent *.gz file you can do this. Optional -type f -atime

find -name "httpd-log*.txt" -type f -mtime +1 -exec tar -vzcf {}.gz {} \;

This will compress

httpd-log01.txt
httpd-log02.txt

to

httpd-log01.txt.gz
httpd-log02.txt.gz

Linq Query Group By and Selecting First Items

See LINQ: How to get the latest/last record with a group by clause

var firstItemsInGroup = from b in mainButtons
                 group b by b.category into g
select g.First();

I assume that mainButtons are already sorted correctly.

If you need to specify custom sort order, use OrderBy override with Comparer.

var firstsByCompareInGroups = from p in rows
        group p by p.ID into grp
        select grp.OrderBy(a => a, new CompareRows()).First();

See an example in my post "Select First Row In Group using Custom Comparer"

Octave/Matlab: Adding new elements to a vector

Just to add to @ThijsW's answer, there is a significant speed advantage to the first method over the concatenation method:

big = 1e5;
tic;
x = rand(big,1);
toc

x = zeros(big,1);
tic;
for ii = 1:big
    x(ii) = rand;
end
toc

x = []; 
tic; 
for ii = 1:big
    x(end+1) = rand; 
end; 
toc 

x = []; 
tic; 
for ii = 1:big
    x = [x rand]; 
end; 
toc

   Elapsed time is 0.004611 seconds.
   Elapsed time is 0.016448 seconds.
   Elapsed time is 0.034107 seconds.
   Elapsed time is 12.341434 seconds.

I got these times running in 2012b however when I ran the same code on the same computer in matlab 2010a I get

Elapsed time is 0.003044 seconds.
Elapsed time is 0.009947 seconds.
Elapsed time is 12.013875 seconds.
Elapsed time is 12.165593 seconds.

So I guess the speed advantage only applies to more recent versions of Matlab

How do I list one filename per output line in Linux?

Use the -1 option (note this is a "one" digit, not a lowercase letter "L"), like this:

ls -1a

First, though, make sure your ls supports -1. GNU coreutils (installed on standard Linux systems) and Solaris do; but if in doubt, use man ls or ls --help or check the documentation. E.g.:

$ man ls
...
       -1     list one file per line.  Avoid '\n' with -q or -b

How to set min-height for bootstrap container

Usually, if you are using bootstrap you can do this to set a min-height of 100%.

 <div class="container-fluid min-vh-100"></div>

this will also solve the footer not sticking at the bottom.

you can also do this from CSS with the following class

.stickDamnFooter{min-height: 100vh;}

if this class does not stick your footer just add position: fixed; to that same css class and you will not have this issue in a lifetime. Cheers.

What is the best way to remove accents (normalize) in a Python unicode string?

Some languages have combining diacritics as language letters and accent diacritics to specify accent.

I think it is more safe to specify explicitly what diactrics you want to strip:

def strip_accents(string, accents=('COMBINING ACUTE ACCENT', 'COMBINING GRAVE ACCENT', 'COMBINING TILDE')):
    accents = set(map(unicodedata.lookup, accents))
    chars = [c for c in unicodedata.normalize('NFD', string) if c not in accents]
    return unicodedata.normalize('NFC', ''.join(chars))

How to copy data from another workbook (excel)?

Would you be happy to make "my file.xls" active if it didn't affect the screen? Turning off screen updating is the way to achieve this, it also has performance improvements (significant if you are doing looping while switching around worksheets / workbooks).

The command to do this is:

    Application.ScreenUpdating = False

Don't forget to turn it back to True when your macros is finished.

How to use XPath in Python?

Another library is 4Suite: http://sourceforge.net/projects/foursuite/

I do not know how spec-compliant it is. But it has worked very well for my use. It looks abandoned.

Oracle SQL - DATE greater than statement

you have to use the To_Date() function to convert the string to date ! http://www.techonthenet.com/oracle/functions/to_date.php

Android: upgrading DB version and adding new table

Your code looks correct. My suggestion is that the database already thinks it's upgraded. If you executed the project after incrementing the version number, but before adding the execSQL call, the database on your test device/emulator may already believe it's at version 2.

A quick way to verify this would be to change the version number to 3 -- if it upgrades after that, you know it was just because your device believed it was already upgraded.

What is .Net Framework 4 extended?

It's the part of the .NET Framework that isn't contained within the Client Profile. See MSDN for more info; specifically:

The .NET Framework is made up of the .NET Framework 4 Client Profile and .NET Framework 4 Extended components that exist separately in Programs and Features.

how to call url of any other website in php

If you meant .. to REDIRECT from that page to another, the function is really simple

header("Location:www.google.com");

How to use CURL via a proxy?

Here is a well tested function which i used for my projects with detailed self explanatory comments


There are many times when the ports other than 80 are blocked by server firewall so the code appears to be working fine on localhost but not on the server

function get_page($url){

global $proxy;
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
//curl_setopt($ch, CURLOPT_PROXY, $proxy);
curl_setopt($ch, CURLOPT_HEADER, 0); // return headers 0 no 1 yes
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // return page 1:yes
curl_setopt($ch, CURLOPT_TIMEOUT, 200); // http request timeout 20 seconds
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); // Follow redirects, need this if the url changes
curl_setopt($ch, CURLOPT_MAXREDIRS, 2); //if http server gives redirection responce
curl_setopt($ch, CURLOPT_USERAGENT,
    "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.7) Gecko/20070914 Firefox/2.0.0.7");
curl_setopt($ch, CURLOPT_COOKIEJAR, "cookies.txt"); // cookies storage / here the changes have been made
curl_setopt($ch, CURLOPT_COOKIEFILE, "cookies.txt");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // false for https
curl_setopt($ch, CURLOPT_ENCODING, "gzip"); // the page encoding

$data = curl_exec($ch); // execute the http request
curl_close($ch); // close the connection
return $data;
}

Spring Boot @Value Properties

Your problem is that you need a static PropertySourcesPlaceholderConfigurer Bean definition in your configuration. I say static with emphasis, because I had a non-static one and it didn't work.

@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
    return new PropertySourcesPlaceholderConfigurer();
}

Putty: Getting Server refused our key Error

For those receiving this error from Windows Server, I received this same error and it was a user account issue. With many organizations, group policy for Administrators may not allow setting up SSH Server and connections. With that type of setup, this must be done from Local Admin account. Might be worth looking into if you have confirmed there are not any typos in the public key.

m2eclipse error

I had same problem with Eclipse 3.7.2 (Indigo) and maven 3.0.4.

In my case, the problem was caused by missing maven-resources-plugin-2.4.3.jar in {user.home}\.m2\repository\org\apache\maven\plugins\maven-resources-plugin\2.4.3 folder. (no idea why maven didn't update it)

Solution:

1.) add dependency to pom.xml

<dependency>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-resources-plugin</artifactId>
    <version>2.4.3</version>
</dependency>

2.) run mvn install from Eclipse or from command line

3.) refresh the project in eclipse (F5)

4.) run Maven > Update Project Configuration... on project (right click)

JAR file is downloaded to local repository and there are no errors in WS.

Detect all Firefox versions in JS

the best solution for me:

_x000D_
_x000D_
function GetIEVersion() {_x000D_
  var sAgent = window.navigator.userAgent;_x000D_
  var Idx = sAgent.indexOf("MSIE");_x000D_
  // If IE, return version number._x000D_
  if (Idx > 0)_x000D_
    return parseInt(sAgent.substring(Idx+ 5, sAgent.indexOf(".", Idx)));_x000D_
_x000D_
  // If IE 11 then look for Updated user agent string._x000D_
  else if (!!navigator.userAgent.match(/Trident\/7\./))_x000D_
    return 11;_x000D_
_x000D_
  else_x000D_
    return 0; //It is not IE_x000D_
_x000D_
}_x000D_
if (GetIEVersion() > 0){_x000D_
    alert("This is IE " + GetIEVersion());_x000D_
  }else {_x000D_
    alert("This no is IE ");_x000D_
  }  
_x000D_
_x000D_
_x000D_

Declare global variables in Visual Studio 2010 and VB.NET

There is no way to declare global variables as you're probably imagining them in VB.NET.

What you can do (as some of the other answers have suggested) is declare everything that you want to treat as a global variable as static variables instead within one particular class:

Public Class GlobalVariables
    Public Shared UserName As String = "Tim Johnson"
    Public Shared UserAge As Integer = 39
End Class

However, you'll need to fully-qualify all references to those variables anywhere you want to use them in your code. In this sense, they are not the type of global variables with which you may be familiar from other languages, because they are still associated with some particular class.

For example, if you want to display a message box in your form's code with the user's name, you'll have to do something like this:

Public Class Form1: Inherits Form

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        MessageBox.Show("Hello, " & GlobalVariables.UserName)
    End Sub

End Class

You can't simply access the variable by typing UserName outside of the class in which it is defined—you must also specify the name of the class in which it is defined.


If the practice of fully-qualifying your variables horrifies or upsets you for whatever reason, you can always import the class that contains your global variable declarations (here, GlobalVariables) at the top of each code file (or even at the project level, in the project's Properties window). Then, you could simply reference the variables by their name.

Imports GlobalVariables

Note that this is exactly the same thing that the compiler is doing for you behind-the-scenes when you declare your global variables in a Module, rather than a Class. In VB.NET, which offers modules for backward-compatibility purposes with previous versions of VB, a Module is simply a sealed static class (or, in VB.NET terms, Shared NotInheritable Class). The IDE allows you to call members from modules without fully-qualifying or importing a reference to them. Even if you decide to go this route, it's worth understanding what is happening behind the scenes in an object-oriented language like VB.NET. I think that as a programmer, it's important to understand what's going on and what exactly your tools are doing for you, even if you decide to use them. And for what it's worth, I do not recommend this as a "best practice" because I feel that it tends towards obscurity and clean object-oriented code/design. It's much more likely that a C# programmer will understand your code if it's written as shown above than if you cram it into a module and let the compiler handle everything.


Note that like at least one other answer has alluded to, VB.NET is a fully object-oriented language. That means, among other things, that everything is an object. Even "global" variables have to be defined within an instance of a class because they are objects as well. Any time you feel the need to use global variables in an object-oriented language, that a sign you need to rethink your design. If you're just making the switch to object-oriented programming, it's more than worth your while to stop and learn some of the basic patterns before entrenching yourself any further into writing code.

Create a batch file to run an .exe with an additional parameter

Found another solution for the same. It will be more helpful.

START C:\"Program Files (x86)"\Test\"Test Automation"\finger.exe ConfigFile="C:\Users\PCName\Desktop\Automation\Documents\Validation_ZoneWise_Default.finger.Config"

finger.exe is a parent program that is calling config solution. Note: if your path folder name consists of spaces, then do not forget to add "".

jquery: get id from class selector

$(".class").click(function(){
    alert($(this).attr('id'));
});

only on jquery button click we can do this class should be written there

How can I get the CheckBoxList selected values, what I have doesn't seem to work C#.NET/VisualWebPart

In your ASPX page you've got the list like this:

    <asp:CheckBoxList ID="YrChkBox" runat="server" 
        onselectedindexchanged="YrChkBox_SelectedIndexChanged"></asp:CheckBoxList>
    <asp:Button ID="button" runat="server" Text="Submit" />

In your code behind aspx.cs page, you have this:

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            // Populate the CheckBoxList items only when it's not a postback.
            YrChkBox.Items.Add(new ListItem("Item 1", "Item1"));
            YrChkBox.Items.Add(new ListItem("Item 2", "Item2"));
        }
    }

    protected void YrChkBox_SelectedIndexChanged(object sender, EventArgs e)
    {
        // Create the list to store.
        List<String> YrStrList = new List<string>();
        // Loop through each item.
        foreach (ListItem item in YrChkBox.Items)
        {
            if (item.Selected)
            {
                // If the item is selected, add the value to the list.
                YrStrList.Add(item.Value);
            }
            else
            {
                // Item is not selected, do something else.
            }
        }
        // Join the string together using the ; delimiter.
        String YrStr = String.Join(";", YrStrList.ToArray());

        // Write to the page the value.
        Response.Write(String.Concat("Selected Items: ", YrStr));
    }

Ensure you use the if (!IsPostBack) { } condition because if you load it every page refresh, it's actually destroying the data.

How to resize datagridview control when form resizes

Set the property of your DataGridView:

Anchor: Top,Left
AutoSizeColumn: Fill
Dock: Fill

async await return Task

Adding the async keyword is just syntactic sugar to simplify the creation of a state machine. In essence, the compiler takes your code;

public async Task MethodName()
{
     return null;
}

And turns it into;

public Task MethodName()
{
     return Task.FromResult<object>(null);
}

If your code has any await keywords, the compiler must take your method and turn it into a class to represent the state machine required to execute it. At each await keyword, the state of variables and the stack will be preserved in the fields of the class, the class will add itself as a completion hook to the task you are waiting on, then return.

When that task completes, your task will be executed again. So some extra code is added to the top of the method to restore the state of variables and jump into the next slab of your code.

See What does async & await generate? for a gory example.

This process has a lot in common with the way the compiler handles iterator methods with yield statements.

How to get last inserted row ID from WordPress database?

Something like this should do it too :

$last = $wpdb->get_row("SHOW TABLE STATUS LIKE 'table_name'");
$lastid = $last->Auto_increment;

Getting result of dynamic SQL into a variable for sql-server

dynamic version

    ALTER PROCEDURE [dbo].[ReseedTableIdentityCol](@p_table varchar(max))-- RETURNS int
    AS
    BEGIN
        -- Declare the return variable here
       DECLARE @sqlCommand nvarchar(1000)
       DECLARE @maxVal INT
       set @sqlCommand = 'SELECT @maxVal = ISNULL(max(ID),0)+1 from '+@p_table
       EXECUTE sp_executesql @sqlCommand, N'@maxVal int OUTPUT',@maxVal=@maxVal OUTPUT
       DBCC CHECKIDENT(@p_table, RESEED, @maxVal)
    END


exec dbo.ReseedTableIdentityCol @p_table='Junk'

How to "properly" print a list?

If you are using Python3:

print('[',end='');print(*L, sep=', ', end='');print(']')

YouTube URL in Video Tag

MediaElement YouTube API example

Wraps the YouTube API in an HTML5 Media API wrapper, so that it can be programmed against as if it was true HTML5 <video>.

<script src="jquery.js"></script>
<script src="mediaelement-and-player.min.js"></script>
<link rel="stylesheet" href="mediaelementplayer.css" />

<video width="640" height="360" id="player1" preload="none">
    <source type="video/youtube" src="http://www.youtube.com/watch?v=nOEw9iiopwI" />
</video>

<script>
    var player = new MediaElementPlayer('#player1');
</script>

Using async/await for multiple tasks

I just want to add to all great answers above, that if you write a library it's a good practice to use ConfigureAwait(false) and get better performance, as said here.

So this snippet seems to be better:

 public static async Task DoWork() 
 {
     int[] ids = new[] { 1, 2, 3, 4, 5 };
     await Task.WhenAll(ids.Select(i => DoSomething(1, i))).ConfigureAwait(false);
 }

A full fiddle link here.

How to fix: "You need to use a Theme.AppCompat theme (or descendant) with this activity"

If you add the android:theme="@style/Theme.AppCompat.Light" to <application> in AndroidManifest.xml file, problem is solving.

C++ undefined reference to defined function

Though previous posters covered your particular error, you can get 'Undefined reference' linker errors when attempting to compile C code with g++, if you don't tell the compiler to use C linkage.

For example you should do this in your C header files:

extern "C" {

...

void myfunc(int param);

...

}

To make 'myfunc' available in C++ programs.

If you still also want to use this from C, wrap the extern "C" { and } in #ifdef __cplusplus preprocessor conditionals, like

#ifdef __cplusplus
extern "C" {
#endif

This way, the extern block will just be “skipped” when using a C compiler.

You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application

You must setup postgresql-server-dev-X.Y, where X.Y. your's servers version, and it will install libpq-dev and other servers variables at modules for server side developing. In my case it was

apt-get install postgresql-server-dev-9.5

Reading package lists... Done Building dependency tree Reading state information... Done The following packages were automatically installed and are no longer required: libmysqlclient18 mysql-common Use 'apt-get autoremove' to remove them. The following extra packages will be installed:
libpq-dev Suggested packages: postgresql-doc-10 The following NEW packages will be installed: libpq-dev postgresql-server-dev-9.5

In your's case

sudo apt-get install postgresql-server-dev-X.Y
sudo apt-get install python-psycopg2

Graphviz's executables are not found (Python 3.4)

To solve this problem,when you install graphviz2.38 successfully, then add your PATH variable to system path.Under System Variables you can click on Path and then clicked Edit and added ;C:\Program Files (x86)\Graphviz2.38\bin to the end of the string and saved.After that,restart your pythonIDE like spyper,then it works well.

Don't forget to close Spyder and then restart.

Verify host key with pysftp

Connect to the server first with a Windows ssh client that uses the known_hosts file. PuTTy stores the data in the windows registry,however OpenSSH uses the known_hosts file, and will add entries in there after you connect. Default location for the file is %USERPROFILE%.ssh. I hope this helps

Best way to store password in database

As a key-hardened salted hash, using a secure algorithm such as sha-512.

Reading from file using read() function

fgets would work for you. here is very good documentation on this :-
http://www.cplusplus.com/reference/cstdio/fgets/

If you don't want to use fgets, following method will work for you :-

int readline(FILE *f, char *buffer, size_t len)
{
   char c; 
   int i;

   memset(buffer, 0, len);

   for (i = 0; i < len; i++)
   {   
      int c = fgetc(f); 

      if (!feof(f)) 
      {   
         if (c == '\r')
            buffer[i] = 0;
         else if (c == '\n')
         {   
            buffer[i] = 0;

            return i+1;
         }   
         else
            buffer[i] = c; 
      }   
      else
      {   
         //fprintf(stderr, "read_line(): recv returned %d\n", c);
         return -1; 
      }   
   }   

   return -1; 
}

How to convert an Object {} to an Array [] of key-value pairs in JavaScript

You can use Object.keys() and map() to do this

_x000D_
_x000D_
var obj = {"1":5,"2":7,"3":0,"4":0,"5":0,"6":0,"7":0,"8":0,"9":0,"10":0,"11":0,"12":0}
var result = Object.keys(obj).map((key) => [Number(key), obj[key]]);

console.log(result);
_x000D_
_x000D_
_x000D_

How to update Ruby Version 2.0.0 to the latest version in Mac OSX Yosemite?

Open Terminal:

sudo gem update --system 

It works!

PowerShell The term is not recognized as cmdlet function script file or operable program

You first have to 'dot' source the script, so for you :

. .\Get-NetworkStatistics.ps1

The first 'dot' asks PowerShell to load the script file into your PowerShell environment, not to start it. You should also use set-ExecutionPolicy Unrestricted or set-ExecutionPolicy AllSigned see(the Execution Policy instructions).

Storing files in SQL Server

There's still no simple answer. It depends on your scenario. MSDN has documentation to help you decide.

There are other options covered here. Instead of storing in the file system directly or in a BLOB, you can use the FileStream or File Table in SQL Server 2012. The advantages to File Table seem like a no-brainier (but admittedly I have no personal first-hand experience with them.)

The article is definitely worth a read.

"git rm --cached x" vs "git reset head --? x"?

There are three places where a file, say, can be - the (committed) tree, the index and the working copy. When you just add a file to a folder, you are adding it to the working copy.

When you do something like git add file you add it to the index. And when you commit it, you add it to the tree as well.

It will probably help you to know the three more common flags in git reset:

git reset [--<mode>] [<commit>]

This form resets the current branch head to <commit> and possibly updates the index (resetting it to the tree of <commit>) and the working tree depending on <mode>, which must be one of the following:
--soft

Does not touch the index file nor the working tree at all (but resets the head to <commit>, just like all modes do). This leaves all your changed files "Changes to be committed", as git status would put it.

--mixed

Resets the index but not the working tree (i.e., the changed files are preserved but not marked for commit) and reports what has not been updated. This is the default action.

--hard

Resets the index and working tree. Any changes to tracked files in the working tree since <commit> are discarded.

Now, when you do something like git reset HEAD, what you are actually doing is git reset HEAD --mixed and it will "reset" the index to the state it was before you started adding files / adding modifications to the index (via git add). In this case, no matter what the state of the working copy was, you didn't change it a single bit, but you changed the index in such a way that is now in sync with the HEAD of the tree. Whether git add was used to stage a previously committed but changed file, or to add a new (previously untracked) file, git reset HEAD is the exact opposite of git add.

git rm, on the other hand, removes a file from the working directory and the index, and when you commit, the file is removed from the tree as well. git rm --cached, however, removes the file from the index alone and keeps it in your working copy. In this case, if the file was previously committed, then you made the index to be different from the HEAD of the tree and the working copy, so that the HEAD now has the previously committed version of the file, the index has no file at all, and the working copy has the last modification of it. A commit now will sync the index and the tree, and the file will be removed from the tree (leaving it untracked in the working copy). When git add was used to add a new (previously untracked) file, then git rm --cached is the exact opposite of git add (and is pretty much identical to git reset HEAD).

Git 2.25 introduced a new command for these cases, git restore, but as of Git 2.28 it is described as “experimental” in the man page, in the sense that the behavior may change.

PySpark: withColumn() with two conditions and three outcomes

The withColumn function in pyspark enables you to make a new variable with conditions, add in the when and otherwise functions and you have a properly working if then else structure. For all of this you would need to import the sparksql functions, as you will see that the following bit of code will not work without the col() function. In the first bit, we declare a new column -'new column', and then give the condition enclosed in when function (i.e. fruit1==fruit2) then give 1 if the condition is true, if untrue the control goes to the otherwise which then takes care of the second condition (fruit1 or fruit2 is Null) with the isNull() function and if true 3 is returned and if false, the otherwise is checked again giving 0 as the answer.

from pyspark.sql import functions as F
df=df.withColumn('new_column', 
    F.when(F.col('fruit1')==F.col('fruit2'), 1)
    .otherwise(F.when((F.col('fruit1').isNull()) | (F.col('fruit2').isNull()), 3))
    .otherwise(0))

Root user/sudo equivalent in Cygwin?

Being unhappy with the available solution, I adopted nu774's script to add security and make it easier to setup and use. The project is available on Github

To use it, just download cygwin-sudo.py and run it via python3 cygwin-sudo.py **yourcommand**.

You can set up an alias for convenience:

alias sudo="python3 /path-to-cygwin-sudo/cygwin-sudo.py"

Add "Are you sure?" to my excel button, how can I?

On your existing button code, simply insert this line before the procedure:

If MsgBox("This will erase everything! Are you sure?", vbYesNo) = vbNo Then Exit Sub

This will force it to quit if the user presses no.

How to assert greater than using JUnit Assert?

You can put it like this

  assertTrue("your fail message ",Long.parseLong(previousTokenValues[1]) > Long.parseLong(currentTokenValues[1]));

Reading a json file in Android

Put that file in assets.

For project created in Android Studio project you need to create assets folder under the main folder.

Read that file as:

public String loadJSONFromAsset(Context context) {
        String json = null;
        try {
            InputStream is = context.getAssets().open("file_name.json");

            int size = is.available();

            byte[] buffer = new byte[size];

            is.read(buffer);

            is.close();

            json = new String(buffer, "UTF-8");


        } catch (IOException ex) {
            ex.printStackTrace();
            return null;
        }
        return json;

    }

and then you can simply read this string return by this function as

JSONObject obj = new JSONObject(json_return_by_the_function);

For further details regarding JSON see http://www.vogella.com/articles/AndroidJSON/article.html

Hope you will get what you want.

How do I download a file with Angular2 or greater

If you only send the parameters to a URL, you can do it this way:

downloadfile(runname: string, type: string): string {
   return window.location.href = `${this.files_api + this.title +"/"+ runname + "/?file="+ type}`;
}

in the service that receives the parameters

Shell Script Syntax Error: Unexpected End of File

I have found that this is sometimes caused by running a MS Dos version of a file. If that's the case dos2ux should fix that.

dos2ux file1 > file2

How to write a stored procedure using phpmyadmin and how to use it through php?

I got it to work in phpAdmin , but only when I removed the "Number of records " phrase.

In my version of phpAdmin I could see the box for changing the delimiters.

Also to see the procedure in the database i went to the phpAdmin home, then information_schema database and then the routines table.

Git command to display HEAD commit id?

Use the command:

git rev-parse HEAD

For the short version:

git rev-parse --short HEAD

How to create a responsive image that also scales up in Bootstrap 3

Sure things!

.img-responsive is the right way to make images responsive with bootstrap 3 You can add some height rule for the picture you want to make responsive, because with responsibility, width changes along the height, fix it and there you are.

How to change a PG column to NULLABLE TRUE?

From the fine manual:

ALTER TABLE mytable ALTER COLUMN mycolumn DROP NOT NULL;

There's no need to specify the type when you're just changing the nullability.

Maven: How to rename the war file for the project?

You can follow the below step to modify the .war file name if you are using maven project.

Open pom.xml file of your maven project and go to the tag <build></build>,

  1. In that give your desired name between this tag : <finalName></finalName>.

    ex. : <finalName>krutik</finalName>

    After deploying this .war you will be able to access url with:
    http://localhost:8080/krutik/

  2. If you want to access the url with slash '/' then you will have to specify then name as below:

    e.x. : <finalName>krutik#maheta</finalName>

    After deploying this .war you will be able to access url with:
    http://localhost:8080/krutik/maheta

How do I conditionally add attributes to React components?

Here is an alternative.

var condition = true;

var props = {
  value: 'foo',
  ...( condition && { disabled: true } )
};

var component = <div { ...props } />;

Or its inline version

var condition = true;

var component = (
  <div
    value="foo"
    { ...( condition && { disabled: true } ) } />
);

How to destroy a JavaScript object?

Structure your code so that all your temporary objects are located inside closures instead of global namespace / global object properties and go out of scope when you've done with them. GC will take care of the rest.

Accessing member of base class

You are incorrectly using the super and this keyword. Here is an example of how they work:

class Animal {
    public name: string;
    constructor(name: string) { 
        this.name = name;
    }
    move(meters: number) {
        console.log(this.name + " moved " + meters + "m.");
    }
}

class Horse extends Animal {
    move() {
        console.log(super.name + " is Galloping...");
        console.log(this.name + " is Galloping...");
        super.move(45);
    }
}

var tom: Animal = new Horse("Tommy the Palomino");

Animal.prototype.name = 'horseee'; 

tom.move(34);
// Outputs:

// horseee is Galloping...
// Tommy the Palomino is Galloping...
// Tommy the Palomino moved 45m.

Explanation:

  1. The first log outputs super.name, this refers to the prototype chain of the object tom, not the object tom self. Because we have added a name property on the Animal.prototype, horseee will be outputted.
  2. The second log outputs this.name, the this keyword refers to the the tom object itself.
  3. The third log is logged using the move method of the Animal base class. This method is called from Horse class move method with the syntax super.move(45);. Using the super keyword in this context will look for a move method on the prototype chain which is found on the Animal prototype.

Remember TS still uses prototypes under the hood and the class and extends keywords are just syntactic sugar over prototypical inheritance.

How to execute a java .class from the command line

Try:

java -cp . Echo "hello"

Assuming that you compiled with:

javac Echo.java 

Then there is a chance that the "current" directory is not in your classpath ( where java looks for .class definitions )

If that's the case and listing the contents of your dir displays:

Echo.java
Echo.class

Then any of this may work:

java -cp . Echo "hello"

or

SET CLASSPATH=%CLASSPATH;.  

java Echo "hello"

And later as Fredrik points out you'll get another error message like.

Exception in thread "main" java.lang.NoSuchMethodError: main

When that happens, go and read his answer :)

No Exception while type casting with a null in java

Many answers here already mention

You can cast null to any reference type

and

If the argument is null, then a string equal to "null"

I wondered where that is specified and looked it up the Java Specification:

The null reference can always be assigned or cast to any reference type (§5.2, §5.3, §5.5).

If the reference is null, it is converted to the string "null" (four ASCII characters n, u, l, l).

MySQL - UPDATE multiple rows with different values in one query

You can use a CASE statement to handle multiple if/then scenarios:

UPDATE table_to_update 
SET  cod_user= CASE WHEN user_rol = 'student' THEN '622057'
                   WHEN user_rol = 'assistant' THEN '2913659'
                   WHEN user_rol = 'admin' THEN '6160230'
               END
    ,date = '12082014'
WHERE user_rol IN ('student','assistant','admin')
  AND cod_office = '17389551';

Implement Validation for WPF TextBoxes

When it comes to DiSaSteR's answer, I noticed a different behavior. textBox.Text shows the text in the TextBox as it was before the user entered a new character, while e.Text shows the single character the user just entered. One challenge is that this character might not get appended to the end, but it will be inserted at the carret position:

private void salary_texbox_PreviewTextInput(object sender, TextCompositionEventArgs e){
  Regex regex = new Regex ( "[^0-9]+" );

  string text;
  if (textBox.CaretIndex==textBox.Text.Length) {
    text = textBox.Text + e.Text;
  } else {
    text = textBox.Text.Substring(0, textBox.CaretIndex)  + e.Text + textBox.Text.Substring(textBox.CaretIndex);
  }

  if(regex.IsMatch(text)){
      MessageBox.Show("Error");
  }
}

How to format date string in java?

If you are looking for a solution to your particular case, it would be:

Date date = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'").parse("2012-05-20T09:00:00.000Z");
String formattedDate = new SimpleDateFormat("dd/MM/yyyy, Ka").format(date);

How to define global variable in Google Apps Script

    var userProperties = PropertiesService.getUserProperties();


function globalSetting(){
  //creating an array
  userProperties.setProperty('gemployeeName',"Rajendra Barge");
  userProperties.setProperty('gemployeeMobile',"9822082320");
  userProperties.setProperty('gemployeeEmail'," [email protected]");
  userProperties.setProperty('gemployeeLastlogin',"03/10/2020");
  
  
  
}


var userProperties = PropertiesService.getUserProperties();
function showUserForm(){

  var templete = HtmlService.createTemplateFromFile("userForm");
  
  var html = templete.evaluate();
  html.setTitle("Customer Data");
  SpreadsheetApp.getUi().showSidebar(html);


}

function appendData(data){
 globalSetting();
 
  var ws = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Data");
  ws.appendRow([data.date,
                data.name,
                data.Kindlyattention,
                data.senderName,
                data.customereMail,
                userProperties.getProperty('gemployeeName'),
                ,
                ,
                data.paymentTerms,
                ,
                userProperties.getProperty('gemployeeMobile'),
                userProperties.getProperty('gemployeeEmail'),
                Utilities.formatDate(new Date(), "GMT+05:30", "dd-MM-yyyy HH:mm:ss")
                
                
  ]);
  
}

function errorMessage(){

Browser.msgBox("! All fields are mandetory");

}

System.Drawing.Image to stream C#

Try the following:

public static Stream ToStream(this Image image, ImageFormat format) {
  var stream = new System.IO.MemoryStream();
  image.Save(stream, format);
  stream.Position = 0;
  return stream;
}

Then you can use the following:

var stream = myImage.ToStream(ImageFormat.Gif);

Replace GIF with whatever format is appropriate for your scenario.

What is the difference between state and props in React?

You can understand it best by relating it to Plain JS functions.

Simply put,

State is the local state of the component which cannot be accessed and modified outside of the component. It's equivalent to local variables in a function.

Plain JS Function

const DummyFunction = () => {
  let name = 'Manoj';
  console.log(`Hey ${name}`)
}

React Component

class DummyComponent extends React.Component {
  state = {
    name: 'Manoj'
  }
  render() {
    return <div>Hello {this.state.name}</div>;
  }

Props, on the other hand, make components reusable by giving components the ability to receive data from their parent component in the form of props. They are equivalent to function parameters.

Plain JS Function

const DummyFunction = (name) => {
  console.log(`Hey ${name}`)
}

// when using the function
DummyFunction('Manoj');
DummyFunction('Ajay');

React Component

class DummyComponent extends React.Component {
  render() {
    return <div>Hello {this.props.name}</div>;
  }

}

// when using the component
<DummyComponent name="Manoj" />
<DummyComponent name="Ajay" />

Credits: Manoj Singh Negi

Article Link: React State vs Props explained

How do I remove a key from a JavaScript object?

If you are using Underscore.js or Lodash, there is a function 'omit' that will do it.
http://underscorejs.org/#omit

var thisIsObject= {
    'Cow' : 'Moo',
    'Cat' : 'Meow',
    'Dog' : 'Bark'
};
_.omit(thisIsObject,'Cow'); //It will return a new object

=> {'Cat' : 'Meow', 'Dog' : 'Bark'}  //result

If you want to modify the current object, assign the returning object to the current object.

thisIsObject = _.omit(thisIsObject,'Cow');

With pure JavaScript, use:

delete thisIsObject['Cow'];

Another option with pure JavaScript.

thisIsObject.cow = undefined;

thisIsObject = JSON.parse(JSON.stringify(thisIsObject ));

jQuery/JavaScript: accessing contents of an iframe

You could use .contents() method of jQuery.

The .contents() method can also be used to get the content document of an iframe, if the iframe is on the same domain as the main page.

$(document).ready(function(){
    $('#frameID').load(function(){
        $('#frameID').contents().find('body').html('Hey, i`ve changed content of <body>! Yay!!!');
    });
});

Return only string message from Spring MVC 3 Controller

@ResponseBody
@RequestMapping(value="/get-text", produces="text/plain")
public String myMethod() {
     return "Response!";
}
  • You see that @ResponseBody ?

It's telling that the method returns some text and not to interpret it as a view etc.

  • You see that produces="text/plain" ?

It's just a good practice as it tells what will be returned from the method :)

can't access mysql from command line mac

Just do the following in your terminal:

echo $PATH

If your given path is not in that string, you have to add it like this: export PATH=$PATH:/usr/local/ or export PATH=$PATH:/usr/local/mysql/bin

Using multiple arguments for string formatting in Python (e.g., '%s ... %s')

You must just put the values into parentheses:

'%s in %s' % (unicode(self.author),  unicode(self.publication))

Here, for the first %s the unicode(self.author) will be placed. And for the second %s, the unicode(self.publication) will be used.

Note: You should favor string formatting over the % Notation. More info here

Where is the .NET Framework 4.5 directory?

The official way to find out if you have 4.5 installed (and not 4.0) is in the registry keys :

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full

Relesae DWORD needs to be bigger than 378675 Here is the Microsoft doc for it

all the other answers of checking the minor version after 4.0.30319.xxxxx seem correct though (msbuild.exe -version , or properties of clr.dll), i just needed something documented (not a blog)

saving a file (from stream) to disk using c#

I have to quote Jon (the master of c#) Skeet:

Well, the easiest way would be to open a file stream and then use:

byte[] data = memoryStream.ToArray(); fileStream.Write(data, 0, data.Length);

That's relatively inefficient though, as it involves copying the buffer. It's fine for small streams, but for huge amounts of data you should consider using:

fileStream.Write(memoryStream.GetBuffer(), 0, memoryStream.Position);

MySQL IF ELSEIF in select query

You have what you have used in stored procedures like this for reference, but they are not intended to be used as you have now. You can use IF as shown by duskwuff. But a Case statement is better for eyes. Like this:

select id, 
    (
    CASE 
        WHEN qty_1 <= '23' THEN price
        WHEN '23' > qty_1 && qty_2 <= '23' THEN price_2
        WHEN '23' > qty_2 && qty_3 <= '23' THEN price_3
        WHEN '23' > qty_3 THEN price_4
        ELSE 1
    END) AS total
 from product;

This looks cleaner. I suppose you do not require the inner SELECT anyway..

Pass PDO prepared statement to variables

Instead of using ->bindParam() you can pass the data only at the time of ->execute():

$data = [   ':item_name' => $_POST['item_name'],   ':item_type' => $_POST['item_type'],   ':item_price' => $_POST['item_price'],   ':item_description' => $_POST['item_description'],   ':image_location' => 'images/'.$_FILES['file']['name'],   ':status' => 0,   ':id' => 0, ];  $stmt->execute($data); 

In this way you would know exactly what values are going to be sent.

Remove NA values from a vector

Trying ?max, you'll see that it actually has a na.rm = argument, set by default to FALSE. (That's the common default for many other R functions, including sum(), mean(), etc.)

Setting na.rm=TRUE does just what you're asking for:

d <- c(1, 100, NA, 10)
max(d, na.rm=TRUE)

If you do want to remove all of the NAs, use this idiom instead:

d <- d[!is.na(d)]

A final note: Other functions (e.g. table(), lm(), and sort()) have NA-related arguments that use different names (and offer different options). So if NA's cause you problems in a function call, it's worth checking for a built-in solution among the function's arguments. I've found there's usually one already there.

SQL Row_Number() function in Where Clause

To get around this issue, wrap your select statement in a CTE, and then you can query against the CTE and use the windowed function's results in the where clause.

WITH MyCte AS 
(
    select   employee_id,
             RowNum = row_number() OVER ( order by employee_id )
    from     V_EMPLOYEE 
    ORDER BY Employee_ID
)
SELECT  employee_id
FROM    MyCte
WHERE   RowNum > 0

Vim and Ctags tips and tricks

I use ALT-left and ALT-right to pop/push from/to the tag stack.

" Alt-right/left to navigate forward/backward in the tags stack
map <M-Left> <C-T>
map <M-Right> <C-]>

If you use hjkl for movement you can map <M-h> and <M-l> instead.

How to pass command line arguments to a shell alias?

To quote the bash man page:

There is no mechanism for using arguments in the replacement text. If arguments are needed, a shell function should be used (see FUNCTIONS below).

So it looks like you've answered your own question -- use a function instead of an alias

Getting error: ISO C++ forbids declaration of with no type

You forgot the return types in your member function definitions:

int ttTree::ttTreeInsert(int value) { ... }
^^^               

and so on.

SQL Server: Null VS Empty String

if it's not a foreign key field, not using empty strings could save you some trouble. only allow nulls if you'll take null to mean something different than an empty string. for example if you have a password field, a null value could indicate that a new user has not created his password yet while an empty varchar could indicate a blank password. for a field like "address2" allowing nulls can only make life difficult. things to watch out for include null references and unexpected results of = and <> operators mentioned by Vagif Verdi, and watching out for these things is often unnecessary programmer overhead.

edit: if performance is an issue see this related question: Nullable vs. non-null varchar data types - which is faster for queries?

How to implement "select all" check box in HTML?

You can Use This code.

var checkbox = document.getElementById("dlCheckAll4Delete");
checkbox.addEventListener("click", function (event) {
  let checkboxes = document.querySelectorAll(".dlMultiDelete");
  checkboxes.forEach(function (ele) {
    ele.checked = !!checkbox.checked;
  });
});

Convert datetime to valid JavaScript date

new Date("2011-07-14 11:23:00"); works fine for me.

What is the correct syntax for 'else if'?

Here is a little refactoring of your function (it does not use "else" or "elif"):

def function(a):
    if a not in (1, 2):
        a = 3
    print(str(a) + "a")

@ghostdog74: Python 3 requires parentheses for "print".

How to detect IE11?

IE11 no longer reports as MSIE, according to this list of changes it's intentional to avoid mis-detection.

What you can do if you really want to know it's IE is to detect the Trident/ string in the user agent if navigator.appName returns Netscape, something like (the untested);

_x000D_
_x000D_
function getInternetExplorerVersion()_x000D_
{_x000D_
  var rv = -1;_x000D_
  if (navigator.appName == 'Microsoft Internet Explorer')_x000D_
  {_x000D_
    var ua = navigator.userAgent;_x000D_
    var re = new RegExp("MSIE ([0-9]{1,}[\\.0-9]{0,})");_x000D_
    if (re.exec(ua) != null)_x000D_
      rv = parseFloat( RegExp.$1 );_x000D_
  }_x000D_
  else if (navigator.appName == 'Netscape')_x000D_
  {_x000D_
    var ua = navigator.userAgent;_x000D_
    var re  = new RegExp("Trident/.*rv:([0-9]{1,}[\\.0-9]{0,})");_x000D_
    if (re.exec(ua) != null)_x000D_
      rv = parseFloat( RegExp.$1 );_x000D_
  }_x000D_
  return rv;_x000D_
}_x000D_
_x000D_
console.log('IE version:', getInternetExplorerVersion());
_x000D_
_x000D_
_x000D_

Note that IE11 (afaik) still is in preview, and the user agent may change before release.

Unable to copy file - access to the path is denied

Just right click on your MVC project and click on the clean option. I had a similar problem and cleaning the project before rebuilding resolved it for me.

download file using an ajax request

@Joao Marcos solution works for me but I had to modify the code to make it work on IE, below if what the code looks like

       downloadFile(url,filename) {
        var that = this;
        const extension =  url.split('/').pop().split('?')[0].split('.').pop();

        var req = new XMLHttpRequest();
        req.open("GET", url, true);
        req.responseType = "blob";
        req.onload = function (event) {
            const fileName = `${filename}.${extension}`;
            const blob = req.response;

            if (window.navigator.msSaveBlob) { // IE
                window.navigator.msSaveOrOpenBlob(blob, fileName);
            } 
            const link = document.createElement('a');
            link.href = window.URL.createObjectURL(blob);                
            link.download = fileName;
            link.click();
            URL.revokeObjectURL(link.href);

        };

        req.send();
    },

Python: How exactly can you take a string, split it, reverse it and join it back together again?

Do you mean like this?

import string
astr='a(b[c])d'

deleter=string.maketrans('()[]','    ')
print(astr.translate(deleter))
# a b c  d
print(astr.translate(deleter).split())
# ['a', 'b', 'c', 'd']
print(list(reversed(astr.translate(deleter).split())))
# ['d', 'c', 'b', 'a']
print(' '.join(reversed(astr.translate(deleter).split())))
# d c b a

Save child objects automatically using JPA Hibernate

I tried the above but I'm getting a database error complaining that the foreign key field in the Child table can not be NULL. Is there a way to tell JPA to automatically set this foreign key into the Child object so it can automatically save children objects?

Well, there are two things here.

First, you need to cascade the save operation (but my understanding is that you are doing this or you wouldn't get a FK constraint violation during inserts in the "child" table)

Second, you probably have a bidirectional association and I think that you're not setting "both sides of the link" correctly. You are supposed to do something like this:

Parent parent = new Parent();
...
Child c1 = new Child();
...
c1.setParent(parent);

List<Child> children = new ArrayList<Child>();
children.add(c1);
parent.setChildren(children);

session.save(parent);

A common pattern is to use link management methods:

@Entity
public class Parent {
    @Id private Long id;

    @OneToMany(mappedBy="parent")
    private List<Child> children = new ArrayList<Child>();

    ...

    protected void setChildren(List<Child> children) {
        this.children = children;
    }

    public void addToChildren(Child child) {
        child.setParent(this);
        this.children.add(child);
    }
}

And the code becomes:

Parent parent = new Parent();
...
Child c1 = new Child();
...

parent.addToChildren(c1);

session.save(parent);
References

set height of imageview as matchparent programmatically

You can try this incase you would like to match parent. The dimensions arrangement is width and height inorder

web = new WebView(this);
        web.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));

Best way to clear a PHP array's values

If you just want to reset a variable to an empty array, you can simply reinitialize it:

$foo = array();

Note that this will maintain any references to it:

$foo = array(1,2,3);
$bar = &$foo;
// ...
$foo = array(); // clear array
var_dump($bar); // array(0) { } -- bar was cleared too!

If you want to break any references to it, unset it first:

$foo = array(1,2,3);
$bar = &$foo;
// ...
unset($foo); // break references
$foo = array(); // re-initialize to empty array
var_dump($bar); // array(3) { 1, 2, 3 } -- $bar is unchanged

Windows 7 environment variable not working in path

To address this problem, I have used setx command which try to set user level variables.

I used below...

setx JAVA_HOME "C:\Program Files\Java\jdk1.8.0_92"

setx PATH %JAVA_HOME%\bin

NOTE: Windows try to append provided variable value to existing variable value. So no need to give extra %PATH%... something like %JAVA_HOME%\bin;%PATH%

MySQL Where DateTime is greater than today

SELECT * 
FROM customer 
WHERE joiningdate >= NOW();

Running Node.js in apache?

You can always do something shell-scripty like:

#!/usr/bin/node

var header = "Content-type: text/plain\n";
var hi = "Hello World from nodetest!";
console.log(header);
console.log(hi);

exit;

Call Javascript onchange event by programmatically changing textbox value

The "onchange" is only fired when the attribute is programmatically changed or when the user makes a change and then focuses away from the field.

Have you looked at using YUI's calendar object? I've coded up a solution that puts the yui calendar inside a yui panel and hides the panel until an associated image is clicked. I'm able to see changes from either.

http://developer.yahoo.com/yui/examples/calendar/formtxt.html

MySQL foreign key constraints, cascade delete

If your cascading deletes nuke a product because it was a member of a category that was killed, then you've set up your foreign keys improperly. Given your example tables, you should have the following table setup:

CREATE TABLE categories (
    id int unsigned not null primary key,
    name VARCHAR(255) default null
)Engine=InnoDB;

CREATE TABLE products (
    id int unsigned not null primary key,
    name VARCHAR(255) default null
)Engine=InnoDB;

CREATE TABLE categories_products (
    category_id int unsigned not null,
    product_id int unsigned not null,
    PRIMARY KEY (category_id, product_id),
    KEY pkey (product_id),
    FOREIGN KEY (category_id) REFERENCES categories (id)
       ON DELETE CASCADE
       ON UPDATE CASCADE,
    FOREIGN KEY (product_id) REFERENCES products (id)
       ON DELETE CASCADE
       ON UPDATE CASCADE
)Engine=InnoDB;

This way, you can delete a product OR a category, and only the associated records in categories_products will die alongside. The cascade won't travel farther up the tree and delete the parent product/category table.

e.g.

products: boots, mittens, hats, coats
categories: red, green, blue, white, black

prod/cats: red boots, green mittens, red coats, black hats

If you delete the 'red' category, then only the 'red' entry in the categories table dies, as well as the two entries prod/cats: 'red boots' and 'red coats'.

The delete will not cascade any farther and will not take out the 'boots' and 'coats' categories.

comment followup:

you're still misunderstanding how cascaded deletes work. They only affect the tables in which the "on delete cascade" is defined. In this case, the cascade is set in the "categories_products" table. If you delete the 'red' category, the only records that will cascade delete in categories_products are those where category_id = red. It won't touch any records where 'category_id = blue', and it would not travel onwards to the "products" table, because there's no foreign key defined in that table.

Here's a more concrete example:

categories:     products:
+----+------+   +----+---------+
| id | name |   | id | name    |
+----+------+   +----+---------+
| 1  | red  |   | 1  | mittens |
| 2  | blue |   | 2  | boots   |
+---++------+   +----+---------+

products_categories:
+------------+-------------+
| product_id | category_id |
+------------+-------------+
| 1          | 1           | // red mittens
| 1          | 2           | // blue mittens
| 2          | 1           | // red boots
| 2          | 2           | // blue boots
+------------+-------------+

Let's say you delete category #2 (blue):

DELETE FROM categories WHERE (id = 2);

the DBMS will look at all the tables which have a foreign key pointing at the 'categories' table, and delete the records where the matching id is 2. Since we only defined the foreign key relationship in products_categories, you end up with this table once the delete completes:

+------------+-------------+
| product_id | category_id |
+------------+-------------+
| 1          | 1           | // red mittens
| 2          | 1           | // red boots
+------------+-------------+

There's no foreign key defined in the products table, so the cascade will not work there, so you've still got boots and mittens listed. There's just no 'blue boots' and no 'blue mittens' anymore.

JavaScript error (Uncaught SyntaxError: Unexpected end of input)

This error is mainly caused by empty returned ajax calls, when trying to parse an empty JSON.

To solve this test if the returned data is empty

$.ajax({
    url: url,
    type: "get",
    dataType: "json",
    success: function (response) {

        if(response.data.length == 0){
            // EMPTY
        }else{
            var obj =jQuery.parseJSON(response.data);
            console.log(obj);
        }
    }
});

How do you append to a file?

The 'a' parameter signifies append mode. If you don't want to use with open each time, you can easily write a function to do it for you:

def append(txt='\nFunction Successfully Executed', file):
    with open(file, 'a') as f:
        f.write(txt)

If you want to write somewhere else other than the end, you can use 'r+':

import os

with open(file, 'r+') as f:
    f.seek(0, os.SEEK_END)
    f.write("text to add")

Finally, the 'w+' parameter grants even more freedom. Specifically, it allows you to create the file if it doesn't exist, as well as empty the contents of a file that currently exists.


Credit for this function goes to @Primusa

iPhone Safari Web App opens links in new window

For those using JQuery Mobile, the above solutions break popup dialog. This will keep links within webapp and allow for popups.

$(document).on('click','a', function (event) {
    if($(this).attr('href').indexOf('#') == 0) {
        return true;
    }
    event.preventDefault();
    window.location = $(this).attr('href');     
});

Could also do it by:

$(document).on('click','a', function (event){
    if($(this).attr('data-rel') == 'popup'){
        return true;
    }
    event.preventDefault();
    window.location = $(this).attr('href');     
});

Laravel: How do I parse this json data in view blade?

You can use json decode then you get php array,and use that value as your own way

<?php 
$leads = json_decode($leads, true);
dd($leads);

Send push to Android by C# using FCM (Firebase Cloud Messaging)

I am using this approach and it is working fine:

 public class PushNotification
 {
     private static readonly ILog Logger = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
        // firebase
     private static Uri FireBasePushNotificationsURL = new Uri("https://fcm.googleapis.com/fcm/send");
     private static string ServerKey = ConfigurationManager.AppSettings["FIREBASESERVERKEY"];

     public static async Task<bool> SendPushNotification(List<SendNotificationModel> notificationData)
     {
         try
         {
             bool sent = false;         
             foreach (var data in notificationData)
             {
                 var messageInformation = new Message()
                 {
                     notification = new Notification()
                     {
                         title = data.Title,
                         text = data.Message,
                         ClickAction = "FCM_PLUGIN_ACTIVITY"
                      },
                      data = data.data,
                      priority="high",
                      to =data.DeviceId
                 };
                 string jsonMessage = JsonConvert.SerializeObject(messageInformation);

                 //Create request to Firebase API
                 var request = new HttpRequestMessage(HttpMethod.Post, FireBasePushNotificationsURL);

                 request.Headers.TryAddWithoutValidation("Authorization", "key=" + ServerKey);
                 request.Content = new StringContent(jsonMessage, Encoding.UTF8, "application/json");

                 HttpResponseMessage result;
                 using (var client = new HttpClient())
                 {
                     result = await client.SendAsync(request);
                     sent =  result.IsSuccessStatusCode;
                 }             
             }

                return sent;
         }
         catch(Exception ex)
         {
             Logger.Error(ex);
             return false;
          }
    }
 }

WCF gives an unsecured or incorrectly secured fault error

In my case, when I changed the wshttpbinding protocol from https to http it started working.

How to use GROUP BY to concatenate strings in MySQL?

SELECT id, GROUP_CONCAT(CAST(name as CHAR)) FROM table GROUP BY id

Will give you a comma-delimited string

Convert Map<String,Object> to Map<String,String>

Not possible.

This a little counter-intuitive.

You're encountering the "Apple is-a fruit" but "Every Fruit is not an Apple"

Go for creating a new map and checking with instance of with String

Hibernate: failed to lazily initialize a collection of role, no session or session was closed

for me it worked the approach that I used in eclipselink as well. Just call the size() of the collection that should be loaded before using it as parameter to pages.

for (Entity e : entityListKeeper.getEntityList()) {
    e.getListLazyLoadedEntity().size();
}

Here entityListKeeper has List of Entity that has list of LazyLoadedEntity. If you have just therelation Entity has list of LazyLoadedEntity then the solution is:

getListLazyLoadedEntity().size();

Converting a factor to numeric without losing information R (as.numeric() doesn't seem to work)

First, factor consists of indices and levels. This fact is very very important when you are struggling with factor.

For example,

> z <- factor(letters[c(3, 2, 3, 4)])

# human-friendly display, but internal structure is invisible
> z
[1] c b c d
Levels: b c d

# internal structure of factor
> unclass(z)
[1] 2 1 2 3
attr(,"levels")
[1] "b" "c" "d"

here, z has 4 elements.
The index is 2, 1, 2, 3 in that order.
The level is associated with each index: 1 -> b, 2 -> c, 3 -> d.

Then, as.numeric converts simply the index part of factor into numeric.
as.character handles the index and levels, and generates character vector expressed by its level.

?as.numeric says that Factors are handled by the default method.

How to use KeyListener

In addition to using KeyListener (as shown by others' answers), sometimes you have to ensure that the JComponent you are using is Focusable. This can be set by adding this to your component(if you are subclassing):

@Override
public void setFocusable(boolean b) {
    super.setFocusable(b);
}

And by adding this to your constructor:

setFocusable(true);

Or, if you are calling the function from a parent class/container:

JComponent childComponent = new JComponent();
childComponent.setFocusable(true);

And then doing all the KeyListener stuff mentioned by others.

Select 2 columns in one and combine them

select column1 || ' ' || column2 as whole_name FROM tablename;

Here || is the concat operator used for concatenating them to single column and ('') inside || used for space between two columns.

How do I add files and folders into GitHub repos?

Simple solution:

git init
git add =A
git commit -m "your commit"
git push -u origin master

if you want add folder to existing repo ..then add folder to local project code

git rm --cached ./folderName
 git add ./folderName

after that

git status
git commit -m "your commit"
git push -u origin master

Test if a variable is a list or tuple

if type(x) is list:
    print 'a list'
elif type(x) is tuple:
    print 'a tuple'
else:
    print 'neither a tuple or a list'

How do I prompt for Yes/No/Cancel input in a Linux shell script?

To get a nice ncurses-like inputbox use the command dialog like this:

#!/bin/bash
if (dialog --title "Message" --yesno "Want to do something risky?" 6 25)
# message box will have the size 25x6 characters
then 
    echo "Let's do something risky"
    # do something risky
else 
    echo "Let's stay boring"
fi

The dialog package is installed by default at least with SUSE Linux. Looks like: the "dialog" command in action

How to output only captured groups with sed?

It's not what the OP asked for (capturing groups) but you can extract the numbers using:

S='This is a sample 123 text and some 987 numbers'
echo "$S" | sed 's/ /\n/g' | sed -r '/([0-9]+)/ !d'

Gives the following:

123
987

Getting the number of filled cells in a column (VBA)

You may also use:

UsedRange.Rows.Count

Is it possible to pull just one file in Git?

git checkout master -- myplugin.js

master = branch name

myplugin.js = file name

Spring's overriding bean

An example from official spring manual:

<bean id="inheritedTestBean" abstract="true"
    class="org.springframework.beans.TestBean">
  <property name="name" value="parent"/>
  <property name="age" value="1"/>
</bean>

<bean id="inheritsWithDifferentClass"
      class="org.springframework.beans.DerivedTestBean"
      parent="inheritedTestBean" init-method="initialize">
  <property name="name" value="override"/>
  <!-- the age property value of 1 will be inherited from  parent -->
</bean>

Is that what you was looking for? Updated link

Redirect all output to file using Bash on Linux?

you can use this syntax to redirect all output stderr and stdout to stdout.txt

<cmd> <args> > allout.txt 2>&1 

iOS Detection of Screenshot?

Latest SWIFT 3:

func detectScreenShot(action: @escaping () -> ()) {
        let mainQueue = OperationQueue.main
        NotificationCenter.default.addObserver(forName: .UIApplicationUserDidTakeScreenshot, object: nil, queue: mainQueue) { notification in
            // executes after screenshot
            action()
        }
    }

In viewDidLoad, call this function

detectScreenShot { () -> () in
 print("User took a screen shot")
}

However,

NotificationCenter.default.addObserver(self, selector: #selector(test), name: .UIApplicationUserDidTakeScreenshot, object: nil)

    func test() {
    //do stuff here
    }

works totally fine. I don't see any points of mainQueue...

How to POST form data with Spring RestTemplate?

Your url String needs variable markers for the map you pass to work, like:

String url = "https://app.example.com/hr/email?{email}";

Or you could explicitly code the query params into the String to begin with and not have to pass the map at all, like:

String url = "https://app.example.com/hr/[email protected]";

See also https://stackoverflow.com/a/47045624/1357094

How do I syntax check a Bash script without running it?

Time changes everything. Here is a web site which provide online syntax checking for shell script.

I found it is very powerful detecting common errors.

enter image description here

About ShellCheck

ShellCheck is a static analysis and linting tool for sh/bash scripts. It's mainly focused on handling typical beginner and intermediate level syntax errors and pitfalls where the shell just gives a cryptic error message or strange behavior, but it also reports on a few more advanced issues where corner cases can cause delayed failures.

Haskell source code is available on GitHub!

How to get a responsive button in bootstrap 3

<a href="#"><button type="button" class="btn btn-info btn-block regular-link"> <span class="text">Create New Board</span></button></a>

We can use btn-block for automatic responsive.

Setting PayPal return URL and making it auto return?

I think that the idea of setting the Auto Return values as described above by Kevin is a bit strange!

Say, for example, that you have a number of websites that use the same PayPal account to handle your payments, or say that you have a number of sections in one website that perform different purchasing tasks, and require different return-addresses when the payment is completed. If I put a button on my page as described above in the 'Sample form using PHP for direct payments' section, you can see that there is a line there:

input type="hidden" name="return" value="https://www.yoursite.com/checkout_complete.php"

where you set the individual return value. Why does it have to be set generally, in the profile section as well?!?!

Also, because you can only set one value in the Profile Section, it means (AFAIK) that you cannot use the Auto Return on a site with multiple actions.

Comments please??

What is the difference between print and puts?

A big difference is if you are displaying arrays. Especially ones with NIL. For example:

print [nil, 1, 2]

gives

[nil, 1, 2]

but

puts [nil, 1, 2]

gives

1
2

Note, no appearing nil item (just a blank line) and each item on a different line.

What is the proper way to display the full InnerException?

Just use exception.ToString()

http://msdn.microsoft.com/en-us/library/system.exception.tostring.aspx

The default implementation of ToString obtains the name of the class that threw the current exception, the message, the result of calling ToString on the inner exception, and the result of calling Environment.StackTrace. If any of these members is null, its value is not included in the returned string.

If there is no error message or if it is an empty string (""), then no error message is returned. The name of the inner exception and the stack trace are returned only if they are not null.

exception.ToString() will also call .ToString() on that exception's inner exception, and so on...

How to stop C# console applications from closing automatically?

Those solutions mentioned change how your program work.

You can off course put #if DEBUG and #endif around the Console calls, but if you really want to prevent the window from closing only on your dev machine under Visual Studio or if VS isn't running only if you explicitly configure it, and you don't want the annoying 'Press any key to exit...' when running from the command line, the way to go is to use the System.Diagnostics.Debugger API's.

If you only want that to work in DEBUG, simply wrap this code in a [Conditional("DEBUG")] void BreakConditional() method.

// Test some configuration option or another
bool launch;
var env = Environment.GetEnvironmentVariable("LAUNCH_DEBUGGER_IF_NOT_ATTACHED");
if (!bool.TryParse(env, out launch))
    launch = false;

// Break either if a debugger is already attached, or if configured to launch
if (launch || Debugger.IsAttached) {
    if (Debugger.IsAttached || Debugger.Launch())
        Debugger.Break();
}

This also works to debug programs that need elevated privileges, or that need to be able to elevate themselves.

how to run the command mvn eclipse:eclipse

Besides the powerful options on the "Run Configurations.." on a well configured project you'll see the maven tasks on the Run As as well.

enter image description here

android set button background programmatically

Using setBackgroundColor() affects the style. So, declare a new style of the same properties with respect to the previous button, with a a different color.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<solid android:color="@color/green"/>
<corners android:radius="10dp"/>
</shape>

Now, use OnClick method.

location.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            location.setBackgroundResource(R.drawable.green);

        }
    });

this changes the button but looks similar to changing the background.

How to print a single backslash?

A backslash needs to be escaped with another backslash.

print('\\')

Delegation: EventEmitter or Observable in Angular

You need to use the Navigation component in the template of ObservingComponent ( dont't forget to add a selector to Navigation component .. navigation-component for ex )

<navigation-component (navchange)='onNavGhange($event)'></navigation-component>

And implement onNavGhange() in ObservingComponent

onNavGhange(event) {
  console.log(event);
}

Last thing .. you don't need the events attribute in @Componennt

events : ['navchange'], 

Passing a variable from one php include file to another: global vs. not

This is all you have to do:

In front.inc

global $name;
$name = 'james';

Form inside a table

Use the "form" attribute, if you want to save your markup:

<form method="GET" id="my_form"></form>

<table>
    <tr>
        <td>
            <input type="text" name="company" form="my_form" />
            <button type="button" form="my_form">ok</button>
        </td>
    </tr>
</table>

(*Form fields outside of the < form > tag)

How to compress an image via Javascript in the browser?

In short:

  • Read the files using the HTML5 FileReader API with .readAsArrayBuffer
  • Create a Blob with the file data and get its url with window.URL.createObjectURL(blob)
  • Create new Image element and set it's src to the file blob url
  • Send the image to the canvas. The canvas size is set to desired output size
  • Get the scaled-down data back from canvas via canvas.toDataURL("image/jpeg",0.7) (set your own output format and quality)
  • Attach new hidden inputs to the original form and transfer the dataURI images basically as normal text
  • On backend, read the dataURI, decode from Base64, and save it

Source: code.

Sourcetree - undo unpushed commits

If You are on another branch, You need first "check to this commit" for commit you want to delete, and only then "reset current branch to this commit" choosing previous wright commit, will work.

How do I install Maven with Yum?

Do you need to install it with yum? There's plenty other possibilities:

  • Grab the binary from http://maven.apache.org/download.html and put it in your /usr/bn
  • If you are using Eclipse you can get the m2eclipse plugin (http://m2eclipse.sonatype.org/) which bundles a version of maven

I can't install pyaudio on Windows? How to solve "error: Microsoft Visual C++ 14.0 is required."?

If you are using Python 3.7.3 and Windows 10 64-bit machine then try the following command. Go to the download folder and Install following command:

pip install PyAudio-0.2.11-cp37-cp37m-win_amd64.whl

and it should work.

How to remove all .svn directories from my application directories

You almost had it. If you want to pass the output of a command as parameters to another one, you'll need to use xargs. Adding -print0 makes sure the script can handle paths with whitespace:

find . -type d -name .svn -print0|xargs -0 rm -rf

How to get a path to the desktop for current user in C#?

// Environment.GetFolderPath
Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData); // Current User's Application Data
Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData); // All User's Application Data
Environment.GetFolderPath(Environment.SpecialFolder.CommonProgramFiles); // Program Files
Environment.GetFolderPath(Environment.SpecialFolder.Cookies); // Internet Cookie
Environment.GetFolderPath(Environment.SpecialFolder.Desktop); // Logical Desktop
Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory); // Physical Desktop
Environment.GetFolderPath(Environment.SpecialFolder.Favorites); // Favorites
Environment.GetFolderPath(Environment.SpecialFolder.History); // Internet History
Environment.GetFolderPath(Environment.SpecialFolder.InternetCache); // Internet Cache
Environment.GetFolderPath(Environment.SpecialFolder.MyComputer); // "My Computer" Folder
Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments); // "My Documents" Folder
Environment.GetFolderPath(Environment.SpecialFolder.MyMusic); // "My Music" Folder
Environment.GetFolderPath(Environment.SpecialFolder.MyPictures); // "My Pictures" Folder
Environment.GetFolderPath(Environment.SpecialFolder.Personal); // "My Document" Folder
Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles); // Program files Folder
Environment.GetFolderPath(Environment.SpecialFolder.Programs); // Programs Folder
Environment.GetFolderPath(Environment.SpecialFolder.Recent); // Recent Folder
Environment.GetFolderPath(Environment.SpecialFolder.SendTo); // "Sent to" Folder
Environment.GetFolderPath(Environment.SpecialFolder.StartMenu); // Start Menu
Environment.GetFolderPath(Environment.SpecialFolder.Startup); // Startup
Environment.GetFolderPath(Environment.SpecialFolder.System); // System Folder
Environment.GetFolderPath(Environment.SpecialFolder.Templates); // Document Templates

mysqli::mysqli(): (HY000/2002): Can't connect to local MySQL server through socket 'MySQL' (2)

When you use just "localhost" the MySQL client library tries to use a Unix domain socket for the connection instead of a TCP/IP connection. The error is telling you that the socket, called MySQL, cannot be used to make the connection, probably because it does not exist (error number 2).

From the MySQL Documentation:

On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. This occurs even if a --port or -P option is given to specify a port number. To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of 127.0.0.1, or the IP address or name of the local server. You can also specify the connection protocol explicitly, even for localhost, by using the --protocol=TCP option.

There are a few ways to solve this problem.

  1. You can just use TCP/IP instead of the Unix socket. You would do this by using 127.0.0.1 instead of localhost when you connect. The Unix socket might by faster and safer to use, though.
  2. You can change the socket in php.ini: open the MySQL configuration file my.cnf to find where MySQL creates the socket, and set PHP's mysqli.default_socket to that path. On my system it's /var/run/mysqld/mysqld.sock.
  3. Configure the socket directly in the PHP script when opening the connection. For example:

    $db = new MySQLi('localhost', 'kamil', '***', '', 0, 
                                  '/var/run/mysqld/mysqld.sock')
    

How can I change from SQL Server Windows mode to mixed mode (SQL Server 2008)?

I had no success with other attempts on a SQL Server 2012. What I did was use SQL Server Management Studio to generate a script to change the value, and got this:

USE [master]
GO
EXEC xp_instance_regwrite N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\MSSQLServer\MSSQLServer', N'LoginMode', REG_DWORD, 2
GO

After that, I enabled the sa account using this:

ALTER LOGIN sa ENABLE ;
GO
ALTER LOGIN sa WITH PASSWORD = '<strongPasswordHere>' ;
GO

...then, I restarted the service, and everything worked!

How to change the color of progressbar in C# .NET 3.5?

Usually the progress bar is either themed or honors the user's color preferences. So for changing the color you either need to turn off visual styles and set ForeColor or draw the control yourself.

As for the continuous style instead of blocks you can set the Style property:

pBar.Style = ProgressBarStyle.Continuous;

Eclipse add Tomcat 7 blank server name

so weird but this worked for me.

  1. close eclipse

  2. start eclipse as eclipse --clean

Algorithm to compare two images

If you're running Linux I would suggest two tools:

align_image_stack from package hugin-tools - is a commandline program that can automatically correct rotation, scaling, and other distortions (it's mostly intended for compositing HDR photography, but works for video frames and other documents too). More information: http://hugin.sourceforge.net/docs/manual/Align_image_stack.html

compare from package imagemagick - a program that can find and count the amount of different pixels in two images. Here's a neat tutorial: http://www.imagemagick.org/Usage/compare/ uising the -fuzz N% you can increase the error tolerance. The higher the N the higher the error tolerance to still count two pixels as the same.

align_image_stack should correct any offset so the compare command will actually have a chance of detecting same pixels.

How to use pip with python 3.4 on windows?

Assuming you don't have any other Python installations, you should be able to do python -m pip after a default installation. Something like the following should be in your system path:

C:\Python34\Scripts

This would obviously be different, if you installed Python in a different location.

Parsing JSON array with PHP foreach

You need to tell it which index in data to use, or double loop through all.

E.g., to get the values in the 4th index in the outside array.:

foreach($user->data[3]->values as $values)
{
     echo $values->value . "\n";
}

To go through all:

foreach($user->data as $mydata)
{
    foreach($mydata->values as $values) {
        echo $values->value . "\n";
    }

}   

How to install requests module in Python 3.4, instead of 2.7

i was facing same issue in beautiful soup , I solved this issue by this command , your issue will also get rectified . You are unable to install requests in python 3.4 because your python libraries are not updated . use this command apt-get install python3-requests Just run it will ask you to add 222 MB space in your hard disk , just press Y and wait for completing process, after ending up whole process . check your problem will be resolved.

Iterating through all the cells in Excel VBA or VSTO 2005

You can use a For Each to iterate through all the cells in a defined range.

Public Sub IterateThroughRange()

Dim wb As Workbook
Dim ws As Worksheet
Dim rng As Range
Dim cell As Range

Set wb = Application.Workbooks(1)
Set ws = wb.Sheets(1)
Set rng = ws.Range("A1", "C3")

For Each cell In rng.Cells
    cell.Value = cell.Address
Next cell

End Sub

How to print out more than 20 items (documents) in MongoDB's shell?

From the shell if you want to show all results you could do db.collection.find().toArray() to get all results without it.

How to get datetime in JavaScript?

@Shadow Wizard's code should return 02:45 PM instead of 14:45 PM. So I modified his code a bit:

function getNowDateTimeStr(){
 var now = new Date();
 var hour = now.getHours() - (now.getHours() >= 12 ? 12 : 0);
return [[AddZero(now.getDate()), AddZero(now.getMonth() + 1), now.getFullYear()].join("/"), [AddZero(hour), AddZero(now.getMinutes())].join(":"), now.getHours() >= 12 ? "PM" : "AM"].join(" ");
}

//Pad given value to the left with "0"
function AddZero(num) {
    return (num >= 0 && num < 10) ? "0" + num : num + "";
}

Disable scrolling on `<input type=number>`

Typescript Variation

Typescript needs to know that you're working with an HTMLElement for type safety, else you'll see lots of Property 'type' does not exist on type 'Element' type of errors.

document.addEventListener("mousewheel", function(event){
  let numberInput = (<HTMLInputElement>document.activeElement);
  if (numberInput.type === "number") {
    numberInput.blur();
  }
});

Selenium wait until document is ready

You can have the thread sleep till the page is reloaded. This is not the best solution, because you need to have an estimate of how long does the page take to load.

driver.get(homeUrl); 
Thread.sleep(5000);
driver.findElement(By.xpath("Your_Xpath_here")).sendKeys(userName);
driver.findElement(By.xpath("Your_Xpath_here")).sendKeys(passWord);
driver.findElement(By.xpath("Your_Xpath_here")).click();

How can I change the language (to english) in Oracle SQL Developer?

Or use the menu: Tools->Preferences->Database->NLS and change language and territory. enter image description here

Reset MySQL root password using ALTER USER statement after install on Mac

remember versions 5.7.23 and up - the user table doesn't has column password instead authentication string so below works while resetting password for a user.

update user set authentication_string=password('root') where user='root';

Angular 4 setting selected option in Dropdown

Lets see an example with Select control
binded to: $scope.cboPais,
source: $scope.geoPaises

HTML

<select 
  ng-model="cboPais"  
  ng-options="item.strPais for item in geoPaises"
  ></select>

JavaScript

$http.get(strUrl2).success(function (response) {
  if (response.length > 0) {
    $scope.geoPaises = response; //Data source
    nIndex = indexOfUnsortedArray(response, 'iPais', default_values.iPais); //array index of default value, using a custom function to search
    if (nIndex >= 0) {
      $scope.cboPais = response[nIndex]; //if index of array was found
    } else {
      $scope.cboPais = response[0]; //select the first element of array
    }
    $scope.geo_getDepartamentos();
  }
}

Deploying Java webapp to Tomcat 8 running in Docker container

You are trying to copy the war file to a directory below webapps. The war file should be copied into the webapps directory.

Remove the mkdir command, and copy the war file like this:

COPY /1.0-SNAPSHOT/my-app-1.0-SNAPSHOT.war /usr/local/tomcat/webapps/myapp.war

Tomcat will extract the war if autodeploy is turned on.

jQuery UI accordion that keeps multiple sections open?

I have done a jQuery plugin that has the same look of jQuery UI Accordion and can keep all tabs\sections open

you can find it here

http://anasnakawa.wordpress.com/2011/01/25/jquery-ui-multi-open-accordion/

works with the same markup

<div id="multiOpenAccordion">
        <h3><a href="#">tab 1</a></h3>
        <div>Lorem ipsum dolor sit amet</div>
        <h3><a href="#">tab 2</a></h3>
        <div>Lorem ipsum dolor sit amet</div>
</div>

Javascript code

$(function(){
        $('#multiOpenAccordion').multiAccordion();
       // you can use a number or an array with active option to specify which tabs to be opened by default:
       $('#multiOpenAccordion').multiAccordion({ active: 1 });
       // OR
       $('#multiOpenAccordion').multiAccordion({ active: [1, 2, 3] });

       $('#multiOpenAccordion').multiAccordion({ active: false }); // no opened tabs
});

UPDATE: the plugin has been updated to support default active tabs option

UPDATE: This plugin is now deprecated.

How to remove item from a python list in a loop?

The already-mentioned list comprehension approach is probably your best bet. But if you absolutely want to do it in-place (for example if x is really large), here's one way:

x = ["ok", "jj", "uy", "poooo", "fren"]
index=0
while index < len(x):
    if len(x[index]) != 2:
        print "length of %s is: %s" %(x[index], len(x[index]))
        del x[index]
        continue
    index+=1

What's the point of 'meta viewport user-scalable=no' in the Google Maps API

From the v3 documentation (Developer's Guide > Concepts > Developing for Mobile Devices):

Android and iOS devices respect the following <meta> tag:

<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />

This setting specifies that the map should be displayed full-screen and should not be resizable by the user. Note that the iPhone's Safari browser requires this <meta> tag be included within the page's <head> element.

Why am I suddenly getting a "Blocked loading mixed active content" issue in Firefox?

I have facing same problem when my site goes from http to https. We have added rule for all request to redirect http to https.

You needs to add the redirection rule for inter site request, but you have to remove the redirection rule for external js/css.

What does file:///android_asset/www/index.html mean?

If someone uses AndroidStudio make sure that the assets folder is placed in

  1. app/src/main/assets

    directory.

Row count on the Filtered data

I have found a way to do this that it requires 2 steps, but it works

' to copy out a filtered selection into a different sheet


number_of_dinosaurs = WorksheetFunction.Count(Worksheets("Dinosaurs").Range("A2", "A3000"))

With Worksheets("Dinosaurs")
    .AutoFilterMode = False
    With .Range("$A$4:$E$" & number_of_dinosaurs)
        .AutoFilter Field:=2, Criteria1:="*teeth*" ' change your criteria to whatever you like
        .SpecialCells(xlCellTypeVisible).Copy Destination:=Worksheets("Bad_Dinosaurs").Range("A1")
    End With
End With


' then do a normal count on the secondary sheet  

number_of_dinosaurs_that_eat_humans = WorksheetFunction.Count(Worksheets("Bad_Dinosaurs").Range("A2", "A30000"))

What exactly is the 'react-scripts start' command?

As Sagiv b.g. pointed out, the npm start command is a shortcut for npm run start. I just wanted to add a real-life example to clarify it a bit more.

The setup below comes from the create-react-app github repo. The package.json defines a bunch of scripts which define the actual flow.

"scripts": {
  "start": "npm-run-all -p watch-css start-js",
  "build": "npm run build-css && react-scripts build",
  "watch-css": "npm run build-css && node-sass-chokidar --include-path ./src --include-path ./node_modules src/ -o src/ --watch --recursive",
  "build-css": "node-sass-chokidar --include-path ./src --include-path ./node_modules src/ -o src/",
  "start-js": "react-scripts start"
},

For clarity, I added a diagram. enter image description here

The blue boxes are references to scripts, all of which you could executed directly with an npm run <script-name> command. But as you can see, actually there are only 2 practical flows:

  • npm run start
  • npm run build

The grey boxes are commands which can be executed from the command line.

So, for instance, if you run npm start (or npm run start) that actually translate to the npm-run-all -p watch-css start-js command, which is executed from the commandline.

In my case, I have this special npm-run-all command, which is a popular plugin that searches for scripts that start with "build:", and executes all of those. I actually don't have any that match that pattern. But it can also be used to run multiple commands in parallel, which it does here, using the -p <command1> <command2> switch. So, here it executes 2 scripts, i.e. watch-css and start-js. (Those last mentioned scripts are watchers which monitor file changes, and will only finish when killed.)

  • The watch-css makes sure that the *.scss files are translated to *.cssfiles, and looks for future updates.

  • The start-js points to the react-scripts start which hosts the website in a development mode.

In conclusion, the npm start command is configurable. If you want to know what it does, then you have to check the package.json file. (and you may want to make a little diagram when things get complicated).

How to check if bootstrap modal is open, so I can use jquery validate?

To avoid the race condition @GregPettit mentions, one can use:

($("element").data('bs.modal') || {})._isShown    // Bootstrap 4
($("element").data('bs.modal') || {}).isShown     // Bootstrap <= 3

as discussed in Twitter Bootstrap Modal - IsShown.

When the modal is not yet opened, .data('bs.modal') returns undefined, hence the || {} - which will make isShown the (falsy) value undefined. If you're into strictness one could do ($("element").data('bs.modal') || {isShown: false}).isShown

How do I deal with "signed/unsigned mismatch" warnings (C4018)?

You can use:

  1. size_t type, to remove warning messages
  2. iterators + distance (like are first hint)
  3. only iterators
  4. function object

For example:

// simple class who output his value
class ConsoleOutput
{
public:
  ConsoleOutput(int value):m_value(value) { }
  int Value() const { return m_value; }
private:
  int m_value;
};

// functional object
class Predicat
{
public:
  void operator()(ConsoleOutput const& item)
  {
    std::cout << item.Value() << std::endl;
  }
};

void main()
{
  // fill list
  std::vector<ConsoleOutput> list;
  list.push_back(ConsoleOutput(1));
  list.push_back(ConsoleOutput(8));

  // 1) using size_t
  for (size_t i = 0; i < list.size(); ++i)
  {
    std::cout << list.at(i).Value() << std::endl;
  }

  // 2) iterators + distance, for std::distance only non const iterators
  std::vector<ConsoleOutput>::iterator itDistance = list.begin(), endDistance = list.end();
  for ( ; itDistance != endDistance; ++itDistance)
  {
    // int or size_t
    int const position = static_cast<int>(std::distance(list.begin(), itDistance));
    std::cout << list.at(position).Value() << std::endl;
  }

  // 3) iterators
  std::vector<ConsoleOutput>::const_iterator it = list.begin(), end = list.end();
  for ( ; it != end; ++it)
  {
    std::cout << (*it).Value() << std::endl;
  }
  // 4) functional objects
  std::for_each(list.begin(), list.end(), Predicat());
}

How to open my files in data_folder with pandas using relative path?

You could use the __file__ attribute:

import os
import pandas as pd
df = pd.read_csv(os.path.join(os.path.dirname(__file__), "../data_folder/data.csv"))

Error: Uncaught (in promise): Error: Cannot match any routes Angular 2

If you are passing id through url please use below

imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    RouterModule.forRoot([
      { path: 'Employees', component: EmployeesComponent, pathMatch: 'full' },
      { path: 'Add', component: EmployeeAddComponent, pathMatch: 'full' },
      **{ path: 'Edit/:id', component: EmployeeEditComponent },
      { path: 'Edit', component: EmployeeEditComponent },**
      { path: '', redirectTo: 'Employees', pathMatch: 'full' }
    ]),
  ],

i.e If you are passing any id we need to both url edit with id and edit url alone

git pull aborted with error filename too long

A few years late, but I'd like to add that if you need to do this in one fell swoop (like I did) you can set the config settings during the clone command. Try this:

git clone -c core.longpaths=true <your.url.here>

Equivalent of Clean & build in Android Studio?

It is probably not a correct way for clean, but I made that to delete unnecessary files, and take less size of a project. It continuously finds and deletes all build and Gradle folders made file clean.bat copy that into the folder where your project is

  set mypath=%cd% 
    for /d /r %mypath% %%a in (build\) do if exist "%%a" rmdir /s /q "%%a"
    for /d /r %mypath% %%a in (.gradle\) do if exist "%%a" rmdir /s /q "%%a"

How to declare a variable in a PostgreSQL query

This solution is based on the one proposed by fei0x but it has the advantages that there is no need to join the value list of constants in the query and constants can be easily listed at the start of the query. It also works in recursive queries.

Basically, every constant is a single-value table declared in a WITH clause which can then be called anywhere in the remaining part of the query.

  • Basic example with two constants:
WITH
    constant_1_str AS (VALUES ('Hello World')),
    constant_2_int AS (VALUES (100))
SELECT *
FROM some_table
WHERE table_column = (table constant_1_str)
LIMIT (table constant_2_int)

Alternatively you can use SELECT * FROM constant_name instead of TABLE constant_name which might not be valid for other query languages different to postgresql.

AngularJS : automatically detect change in model

In views with {{}} and/or ng-model, Angular is setting up $watch()es for you behind the scenes.

By default $watch compares by reference. If you set the third parameter to $watch to true, Angular will instead "shallow" watch the object for changes. For arrays this means comparing the array items, for object maps this means watching the properties. So this should do what you want:

$scope.$watch('myModel', function() { ... }, true);

Update: Angular v1.2 added a new method for this, `$watchCollection():

$scope.$watchCollection('myModel', function() { ... });

Note that the word "shallow" is used to describe the comparison rather than "deep" because references are not followed -- e.g., if the watched object contains a property value that is a reference to another object, that reference is not followed to compare the other object.

Adding options to select with javascript

Often you have an array of related records, I find it easy and fairly declarative to fill select this way:

selectEl.innerHTML = array.map(c => '<option value="'+c.id+'">'+c.name+'</option>').join('');

This will replace existing options.
You can use selectEl.insertAdjacentHTML('afterbegin', str); to add them to the top instead.
And selectEl.insertAdjacentHTML('beforeend', str); to add them to the bottom of the list.

IE11 compatible syntax:

array.map(function (c) { return '<option value="'+c.id+'">'+c.name+'</option>'; }).join('');

Load local JSON file into variable

If you pasted your object into content.json directly, it is invalid JSON. JSON keys and values must be wrapped in double quotes (" not ') unless the value is numeric, boolean, null, or composite (array or object). JSON cannot contain functions or undefined values. Below is your object as valid JSON.

{
  "id": "whatever",
  "name": "start",
  "children": [
    {
      "id": "0.9685",
      "name": " contents:queue"
    },
    {
      "id": "0.79281",
      "name": " contents:mqq_error"
    }
  ]
}

You also had an extra }.

What are the valid Style Format Strings for a Reporting Services [SSRS] Expression?

As mentioned, you can use:

=Format(Fields!Price.Value, "C")

A digit after the "C" will specify precision:

=Format(Fields!Price.Value, "C0")
=Format(Fields!Price.Value, "C1")

You can also use Excel-style masks like this:

=Format(Fields!Price.Value, "#,##0.00")

Haven't tested the last one, but there's the idea. Also works with dates:

=Format(Fields!Date.Value, "yyyy-MM-dd")

How to display data from database into textbox, and update it

Wrap your all statements in !IsPostBack condition on page load.

protected void Page_Load(object sender, EventArgs e)
{
   if(!IsPostBack)
   {
      // all statements
   }
}

This will fix your issue.

Error: Could not create the Java Virtual Machine Mac OSX Mavericks

Try : java -version , then if you see java 11

try to delete with terminal : cd /Library/Java/JavaVirtualMachines rm -rf openjdk-11.0.1.jdk

if it doesn't try delete manually: 1) click on finder 2) go to folder 3) post /Library/Java/JavaVirtualMachines 4) delete java 11 .

then try java version and you will see : java version "1.8.0_191"

How do I check when a UITextField changes?

The way I've handled it so far: in UITextFieldDelegate

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool
{
    // text hasn't changed yet, you have to compute the text AFTER the edit yourself
    let updatedString = (textField.text as NSString?)?.stringByReplacingCharactersInRange(range, withString: string)

    // do whatever you need with this updated string (your code)


    // always return true so that changes propagate
    return true
}

Swift4 version

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    let updatedString = (textField.text as NSString?)?.replacingCharacters(in: range, with: string)
    return true
}

How to set DialogFragment's width and height?

Add to your FragmentDialog:

public void onResume() {
    Window window = getDialog().getWindow();
    Point size = new Point();
    Display display = window.getWindowManager().getDefaultDisplay();
    display.getSize(size);
    window.setLayout( (int)(size.x * 0.9), WindowManager.LayoutParams.WRAP_CONTENT );
    window.setGravity( Gravity.CENTER );
    super.onResume();
}

How to force HTTPS using a web.config file

For those using ASP.NET MVC. You can use the RequireHttpsAttribute to force all responses to be HTTPS:

GlobalFilters.Filters.Add(new RequireHttpsAttribute());

Other things you may also want to do to help secure your site:

  1. Force Anti-Forgery tokens to use SSL/TLS:

    AntiForgeryConfig.RequireSsl = true;
    
  2. Require Cookies to require HTTPS by default by changing the Web.config file:

    <system.web>
        <httpCookies httpOnlyCookies="true" requireSSL="true" />
    </system.web>
    
  3. Use the NWebSec.Owin NuGet package and add the following line of code to enable Strict Transport Security (HSTS) across the site. Don't forget to add the Preload directive below and submit your site to the HSTS Preload site. More information here and here. Note that if you are not using OWIN, there is a Web.config method you can read up on on the NWebSec site.

    // app is your OWIN IAppBuilder app in Startup.cs
    app.UseHsts(options => options.MaxAge(days: 720).Preload());
    
  4. Use the NWebSec.Owin NuGet package and add the following line of code to enable Public Key Pinning (HPKP) across the site. More information here and here.

    // app is your OWIN IAppBuilder app in Startup.cs
    app.UseHpkp(options => options
        .Sha256Pins(
            "Base64 encoded SHA-256 hash of your first certificate e.g. cUPcTAZWKaASuYWhhneDttWpY3oBAkE3h2+soZS7sWs=",
            "Base64 encoded SHA-256 hash of your second backup certificate e.g. M8HztCzM3elUxkcjR2S5P4hhyBNf6lHkmjAHKhpGPWE=")
        .MaxAge(days: 30));
    
  5. Include the https scheme in any URL's used. Content Security Policy (CSP) HTTP header and Subresource Integrity (SRI) do not play nice when you imit the scheme in some browsers. It is better to be explicit about HTTPS. e.g.

    <script src="https://ajax.aspnetcdn.com/ajax/bootstrap/3.3.4/bootstrap.min.js">
    </script>
    
  6. Use the ASP.NET MVC Boilerplate Visual Studio project template to generate a project with all of this and much more built in. You can also view the code on GitHub.

How to add new DataRow into DataTable?

    GRV.DataSource = Class1.DataTable;
            GRV.DataBind();

Class1.GRV.Rows[e.RowIndex].Delete();
        GRV.DataSource = Class1.DataTable;
        GRV.DataBind();

Case insensitive 'Contains(string)'

if ("strcmpstring1".IndexOf(Convert.ToString("strcmpstring2"), StringComparison.CurrentCultureIgnoreCase) >= 0){return true;}else{return false;}

Floating point vs integer calculations on modern hardware

TIL This varies (a lot). Here are some results using gnu compiler (btw I also checked by compiling on machines, gnu g++ 5.4 from xenial is a hell of a lot faster than 4.6.3 from linaro on precise)

Intel i7 4700MQ xenial

short add: 0.822491
short sub: 0.832757
short mul: 1.007533
short div: 3.459642
long add: 0.824088
long sub: 0.867495
long mul: 1.017164
long div: 5.662498
long long add: 0.873705
long long sub: 0.873177
long long mul: 1.019648
long long div: 5.657374
float add: 1.137084
float sub: 1.140690
float mul: 1.410767
float div: 2.093982
double add: 1.139156
double sub: 1.146221
double mul: 1.405541
double div: 2.093173

Intel i3 2370M has similar results

short add: 1.369983
short sub: 1.235122
short mul: 1.345993
short div: 4.198790
long add: 1.224552
long sub: 1.223314
long mul: 1.346309
long div: 7.275912
long long add: 1.235526
long long sub: 1.223865
long long mul: 1.346409
long long div: 7.271491
float add: 1.507352
float sub: 1.506573
float mul: 2.006751
float div: 2.762262
double add: 1.507561
double sub: 1.506817
double mul: 1.843164
double div: 2.877484

Intel(R) Celeron(R) 2955U (Acer C720 Chromebook running xenial)

short add: 1.999639
short sub: 1.919501
short mul: 2.292759
short div: 7.801453
long add: 1.987842
long sub: 1.933746
long mul: 2.292715
long div: 12.797286
long long add: 1.920429
long long sub: 1.987339
long long mul: 2.292952
long long div: 12.795385
float add: 2.580141
float sub: 2.579344
float mul: 3.152459
float div: 4.716983
double add: 2.579279
double sub: 2.579290
double mul: 3.152649
double div: 4.691226

DigitalOcean 1GB Droplet Intel(R) Xeon(R) CPU E5-2630L v2 (running trusty)

short add: 1.094323
short sub: 1.095886
short mul: 1.356369
short div: 4.256722
long add: 1.111328
long sub: 1.079420
long mul: 1.356105
long div: 7.422517
long long add: 1.057854
long long sub: 1.099414
long long mul: 1.368913
long long div: 7.424180
float add: 1.516550
float sub: 1.544005
float mul: 1.879592
float div: 2.798318
double add: 1.534624
double sub: 1.533405
double mul: 1.866442
double div: 2.777649

AMD Opteron(tm) Processor 4122 (precise)

short add: 3.396932
short sub: 3.530665
short mul: 3.524118
short div: 15.226630
long add: 3.522978
long sub: 3.439746
long mul: 5.051004
long div: 15.125845
long long add: 4.008773
long long sub: 4.138124
long long mul: 5.090263
long long div: 14.769520
float add: 6.357209
float sub: 6.393084
float mul: 6.303037
float div: 17.541792
double add: 6.415921
double sub: 6.342832
double mul: 6.321899
double div: 15.362536

This uses code from http://pastebin.com/Kx8WGUfg as benchmark-pc.c

g++ -fpermissive -O3 -o benchmark-pc benchmark-pc.c

I've run multiple passes, but this seems to be the case that general numbers are the same.

One notable exception seems to be ALU mul vs FPU mul. Addition and subtraction seem trivially different.

Here is the above in chart form (click for full size, lower is faster and preferable):

Chart of above data

Update to accomodate @Peter Cordes

https://gist.github.com/Lewiscowles1986/90191c59c9aedf3d08bf0b129065cccc

i7 4700MQ Linux Ubuntu Xenial 64-bit (all patches to 2018-03-13 applied)
    short add: 0.773049
    short sub: 0.789793
    short mul: 0.960152
    short div: 3.273668
      int add: 0.837695
      int sub: 0.804066
      int mul: 0.960840
      int div: 3.281113
     long add: 0.829946
     long sub: 0.829168
     long mul: 0.960717
     long div: 5.363420
long long add: 0.828654
long long sub: 0.805897
long long mul: 0.964164
long long div: 5.359342
    float add: 1.081649
    float sub: 1.080351
    float mul: 1.323401
    float div: 1.984582
   double add: 1.081079
   double sub: 1.082572
   double mul: 1.323857
   double div: 1.968488
AMD Opteron(tm) Processor 4122 (precise, DreamHost shared-hosting)
    short add: 1.235603
    short sub: 1.235017
    short mul: 1.280661
    short div: 5.535520
      int add: 1.233110
      int sub: 1.232561
      int mul: 1.280593
      int div: 5.350998
     long add: 1.281022
     long sub: 1.251045
     long mul: 1.834241
     long div: 5.350325
long long add: 1.279738
long long sub: 1.249189
long long mul: 1.841852
long long div: 5.351960
    float add: 2.307852
    float sub: 2.305122
    float mul: 2.298346
    float div: 4.833562
   double add: 2.305454
   double sub: 2.307195
   double mul: 2.302797
   double div: 5.485736
Intel Xeon E5-2630L v2 @ 2.4GHz (Trusty 64-bit, DigitalOcean VPS)
    short add: 1.040745
    short sub: 0.998255
    short mul: 1.240751
    short div: 3.900671
      int add: 1.054430
      int sub: 1.000328
      int mul: 1.250496
      int div: 3.904415
     long add: 0.995786
     long sub: 1.021743
     long mul: 1.335557
     long div: 7.693886
long long add: 1.139643
long long sub: 1.103039
long long mul: 1.409939
long long div: 7.652080
    float add: 1.572640
    float sub: 1.532714
    float mul: 1.864489
    float div: 2.825330
   double add: 1.535827
   double sub: 1.535055
   double mul: 1.881584
   double div: 2.777245

MySQL Data - Best way to implement paging?

Define OFFSET for the query. For example

page 1 - (records 01-10): offset = 0, limit=10;

page 2 - (records 11-20) offset = 10, limit =10;

and use the following query :

SELECT column FROM table LIMIT {someLimit} OFFSET {someOffset};

example for page 2:

SELECT column FROM table
LIMIT 10 OFFSET 10;

How to execute raw queries with Laravel 5.1?

    DB::statement("your query")

I used it for add index to column in migration

cell format round and display 2 decimal places

I use format, Number, 2 decimal places & tick ' use 1000 separater ', then go to 'File', 'Options', 'Advanced', scroll down to 'When calculating this workbook' and tick 'set precision as displayed'. You get an error message about losing accuracy, that's good as it means it is rounding to 2 decimal places. So much better than bothering with adding a needless ROUND function.

Change image source with JavaScript

Your only real problem is you are passing a string, not an object with a .src property

Some suggestions:

  • Use a naturally clickable element trigger, such as <button>
  • Use data- prefixed attributes for event data on the element
  • Use late bound events when the DOM is ready.

Markup:

<div id="main_img">
  <img id="img" src="1772031_29_b.jpg">
</div>
<ul id="thumb_img">
  <li><button data-src='1772031_29_b.jpg'><img src='1772031_29_t.jpg' /></button></li>
  <li><button data-src='1772031_55_b.jpg'><img src='1772031_55_t.jpg' /></button></li>
  <li><button data-src='1772031_53_b.jpg'><img src='1772031_53_t.jpg' /></button></li>
</ul>

JavaScript:

If you need to support IE and other legacy browsers, Use a proper polyfill for Array.from

function clickedButton(btn, event) {
  document.getElementById('img').src = btn.getAttribute('data-src');
}

function bindClick(btn) {
  btn.addEventListener('click', clickedButton.bind(null,btn));
}

// Setup click handler(s) when content is loaded
document.addEventListener("DOMContentLoaded", function(){
  Array.from(document.querySelectorAll('#thumb_img > button'))
    .forEach(bindClick));
});

Edit: Vanilla JS for modern browsers.

Python spacing and aligning strings

You can use expandtabs to specify the tabstop, like this:

>>> print ('Location:'+'10-10-10-10'+'\t'+ 'Revision: 1'.expandtabs(30))
>>> print ('District: Tower'+'\t'+ 'Date: May 16, 2012'.expandtabs(30))
#Output:
Location:10-10-10-10          Revision: 1
District: Tower               Date: May 16, 2012

Git list of staged files

The best way to do this is by running the command:

git diff --name-only --cached

When you check the manual you will likely find the following:

--name-only
    Show only names of changed files.

And on the example part of the manual:

git diff --cached
    Changes between the index and your current HEAD.

Combined together you get the changes between the index and your current HEAD and Show only names of changed files.

Update: --staged is also available as an alias for --cached above in more recent git versions.

Move a view up only when the keyboard covers an input field

Just use this extension to move any UIView when keyboard is presented.

extension UIView {
    func bindToKeyboard(){
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillChange(_:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)
    }

    @objc func keyboardWillChange(_ notification: NSNotification){
        let duration = notification.userInfo![UIKeyboardAnimationDurationUserInfoKey] as! Double
        let curve = notification.userInfo![UIKeyboardAnimationCurveUserInfoKey] as! UInt
        let beginningFrame = (notification.userInfo![UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
        let endFrame = (notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue

        let deltaY = endFrame.origin.y - beginningFrame.origin.y

        UIView.animateKeyframes(withDuration: duration, delay: 0.0, options: UIViewKeyframeAnimationOptions(rawValue: curve), animations: {
            self.frame.origin.y += deltaY
        }, completion: nil)
    }
}

Then in your viewdidload bind your view to the keyboard

UiView.bindToKeyboard()

How to delete all files older than 3 days when "Argument list too long"?

Can also use:

find . -mindepth 1 -mtime +3 -delete

To not delete target directory

Install a module using pip for specific python version

for python2 use:

py -2 -m pip install beautifulsoup4

How to get the index of an item in a list in a single step?

  1. Simple solution to find index for any string value in the List.

Here is code for List Of String:

int indexOfValue = myList.FindIndex(a => a.Contains("insert value from list"));
  1. Simple solution to find index for any Integer value in the List.

Here is Code for List Of Integer:

    int indexOfNumber = myList.IndexOf(/*insert number from list*/);

How to execute a Ruby script in Terminal?

Open your terminal and open folder where file is saved.
Ex /home/User1/program/test.rb

  1. Open terminal
  2. cd /home/User1/program
  3. ruby test.rb

format or test.rb

class Test 
  def initialize
   puts "I love India"
  end
end

# initialize object
Test.new

output

I love India