Programs & Examples On #Vcl

This tag is used for questions regarding the Visual Component Library used in Borland/CodeGear/Embarcadero Delphi and C++Builder products. Do not confuse this with the Varnish Configuration Language (VCL). Use the "varnish-vcl" tag for questions related to that product.

Module is not available, misspelled or forgot to load (but I didn't)

I got this error when my service declaration was inside a non-invoked function (IIFE). The last line below did NOT have the extra () to run and define the service.

(function() {
    "use strict";

    angular.module("reviewService", [])
        .service("reviewService", reviewService);

    function reviewService($http, $q, $log) {
        //
    }
}());

select from one table, insert into another table oracle sql query

You will get useful information from here.

SELECT ticker
INTO quotedb
FROM tickerdb;

How do I read a response from Python Requests?

Requests doesn't have an equivalent to Urlib2's read().

>>> import requests
>>> response = requests.get("http://www.google.com")
>>> print response.content
'<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage"><head>....'
>>> print response.content == response.text
True

It looks like the POST request you are making is returning no content. Which is often the case with a POST request. Perhaps it set a cookie? The status code is telling you that the POST succeeded after all.

Edit for Python 3:

Python now handles data types differently. response.content returns a sequence of bytes (integers that represent ASCII) while response.text is a string (sequence of chars).

Thus,

>>> print response.content == response.text
False

>>> print str(response.content) == response.text
True

Why isn't .ico file defined when setting window's icon?

I recently ran into this problem and didn't find any of the answers very relevant so I decided to make a SO account for this.

Solution 1: Convert your .ico File online there are a lot of site out there

Solution 2: Convert .ico File in photoshop

If you or your Editor just renamed your image file to *.ico then it is not going to work.
If you see the image icon from your Windows/OS folder then it is working

LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

I had this happen in Visual Studio 2015 too for an interesting reason. Just adding it here in case it happens to someone else.

I already had number of files in project and I was adding another one that would have main function in it, however when I initially added the file I made a typo in the extension (.coo instead of .cpp). I corrected that but when I was done I got this error. It turned out that Visual Studio was being smart and when file was added it decided that it is not a source file due to the initial extension.

Right-clicking on file in solution explorer and selecting Properties -> General -> ItemType and setting it to "C/C++ compiler" fixed the issue.

jQuery: Check if div with certain class name exists

var x = document.getElementsByClassName("class name");
if (x[0]) {
alert('has');
} else {
alert('no has');
}

How to turn on WCF tracing?

Instead of you manual adding the tracing enabling bit into web.config you can also try using the WCF configuration editor which comes with VS SDK to enable tracing

https://stackoverflow.com/a/16715631/2218571

Using a Loop to add objects to a list(python)

The problem appears to be that you are reinitializing the list to an empty list in each iteration:

while choice != 0:
    ...
    a = []
    a.append(s)

Try moving the initialization above the loop so that it is executed only once.

a = []
while choice != 0:
    ...
    a.append(s)

Get a Div Value in JQuery

myDivObj = document.getElementById("myDiv");
if ( myDivObj ) {
   alert ( myDivObj.innerHTML ); 
}else{
   alert ( "Alien Found" );
}

Above code will show the innerHTML, i.e if you have used html tags inside div then it will show even those too. probably this is not what you expected. So another solution is to use: innerText / textContent property [ thanx to bobince, see his comment ]

function showDivText(){
            divObj = document.getElementById("myDiv");
            if ( divObj ){
                if ( divObj.textContent ){ // FF
                    alert ( divObj.textContent );
                }else{  // IE           
                    alert ( divObj.innerText );  //alert ( divObj.innerHTML );
                } 
            }  
        }

Minimum and maximum value of z-index?

While INT_MAX is probably the safest bet, WebKit apparently uses doubles internally and thus allows very large numbers (to a certain precision). LLONG_MAX e.g. works fine (at least in 64-Bit Chromium and WebkitGTK), but will be rounded to 9223372036854776000.

(Although you should consider carefully whether you really, really need this many z indices…).

What is the Windows version of cron?

Is there also a way to invoke this feature (which based on answers is called the Task Scheduler) programatically [...]?

Task scheduler API on MSDN.

How to decrypt the password generated by wordpress

This is one of the proposed solutions found in the article Jacob mentioned, and it worked great as a manual way to change the password without having to use the email reset.

  1. In the DB table wp_users, add a key, like abc123 to the user_activation column.
  2. Visit yoursite.com/wp-login.php?action=rp&key=abc123&login=yourusername
  3. You will be prompted to enter a new password.

Temporarily switch working copy to a specific Git commit

First, use git log to see the log, pick the commit you want, note down the sha1 hash that is used to identify the commit. Next, run git checkout hash. After you are done, git checkout original_branch. This has the advantage of not moving the HEAD, it simply switches the working copy to a specific commit.

.attr('checked','checked') does not work

It works, but

$('input[name="myname"][checked]').val()

will return the value of the first element with attribute checked. And the a radio button still has this attribute (and it comes before the b button). Selecting b does not remove the checked attribute from a.

You can use jQuery's :checked:

$('input[name="myname"]:checked').val()

DEMO


Further notes:

  • Using $('b').attr('checked',true); is enough.
  • As others mentioned, don't use inline event handlers, use jQuery to add the event handler.

How to get the number of characters in a string

There is a way to get count of runes without any packages by converting string to []rune as len([]rune(YOUR_STRING)):

package main

import "fmt"

func main() {
    russian := "??????? ? ??????"
    english := "Sputnik & pogrom"

    fmt.Println("count of bytes:",
        len(russian),
        len(english))

    fmt.Println("count of runes:",
        len([]rune(russian)),
        len([]rune(english)))

}

count of bytes 30 16

count of runes 16 16

CASE WHEN statement for ORDER BY clause

declare @OrderByCmd  nvarchar(2000)
declare @OrderByName nvarchar(100)
declare @OrderByCity nvarchar(100)
set @OrderByName='Name'    
set @OrderByCity='city'
set @OrderByCmd= 'select * from customer Order By '+@OrderByName+','+@OrderByCity+''
EXECUTE sp_executesql @OrderByCmd 

TypeError: unsupported operand type(s) for /: 'str' and 'str'

The first thing you should do is learn to read error messages. What does it tell you -- that you can't use two strings with the divide operator.

So, ask yourself why they are strings and how do you make them not-strings. They are strings because all input is done via strings. And the way to make then not-strings is to convert them.

One way to convert a string to an integer is to use the int function. For example:

percent = (int(pyc) / int(tpy)) * 100

Elegant way to read file into byte[] array in Java

A long time ago:

Call any of these

byte[] org.apache.commons.io.FileUtils.readFileToByteArray(File file)
byte[] org.apache.commons.io.IOUtils.toByteArray(InputStream input) 

From

http://commons.apache.org/io/

If the library footprint is too big for your Android app, you can just use relevant classes from the commons-io library

Today (Java 7+ or Android API Level 26+)

Luckily, we now have a couple of convenience methods in the nio packages. For instance:

byte[] java.nio.file.Files.readAllBytes(Path path)

Javadoc here

Couldn't connect to server 127.0.0.1:27017

Err : Couldn't connect to server 127.0.0.1:27017

This is solution for WINDOWS users enter code here 1. Create directory:

mkdir c:\mongo\data\db
  1. Install service: first go to your bin directory in programs files of MongoDB with cd

mongod.exe --install --logpath

  1. Start MongoDB:

    net start MongoDB

4.Start Mongo Shell:

`c:\mongo\bin\mongo.exe` or

go to until bin and enter mongo

Note : Open terminal in Administrator mode

What can be the reasons of connection refused errors?

In my case, it happens when the site is blocked in my country and I don't use VPN. For example when I try to access vimeo.com from Indonesia which is blocked.

C++ for each, pulling from vector elements

For next examples assumed that you use C++11. Example with ranged-based for loops:

for (auto &attack : m_attack) // access by reference to avoid copying
{  
    if (attack->m_num == input)
    {
        attack->makeDamage();
    }
}

You should use const auto &attack depending on the behavior of makeDamage().

You can use std::for_each from standard library + lambdas:

std::for_each(m_attack.begin(), m_attack.end(),
        [](Attack * attack)
        {
            if (attack->m_num == input)
            {
                attack->makeDamage();
            }
        }
);

If you are uncomfortable using std::for_each, you can loop over m_attack using iterators:

for (auto attack = m_attack.begin(); attack != m_attack.end(); ++attack)
{  
    if (attack->m_num == input)
    {
        attack->makeDamage();
    }
}

Use m_attack.cbegin() and m_attack.cend() to get const iterators.

How do I run Google Chrome as root?

i followed these steps

Step 1. Open /etc/chromium/default file with editor
Step 2. Replace or add this line 
CHROMIUM_FLAGS="--password-store=detect --user-data-dir=/root/chrome-profile/"
Step 3. Save it..

Thats it.... Start the browser...

How do you check if a certain index exists in a table?

If the hidden purpose of your question is to DROP the index before making INSERT to a large table, then this is useful one-liner:

DROP INDEX IF EXISTS [IndexName] ON [dbo].[TableName]

This syntax is available since SQL Server 2016. Documentation for IF EXISTS:

https://blogs.msdn.microsoft.com/sqlserverstorageengine/2015/11/03/drop-if-exists-new-thing-in-sql-server-2016/

In case you deal with a primery key instead, then use this:

ALTER TABLE [TableName] DROP CONSTRAINT IF EXISTS [PK_name] 

How do I check if a variable exists?

I created a custom function.

def exists(var):
     return var in globals()

Then the call the function like follows replacing variable_name with the variable you want to check:

exists("variable_name")

Will return True or False

How can I initialize an ArrayList with all zeroes in Java?

Java 8 implementation (List initialized with 60 zeroes):

List<Integer> list = IntStream.of(new int[60])
                    .boxed()
                    .collect(Collectors.toList());
  • new int[N] - creates an array filled with zeroes & length N
  • boxed() - each element boxed to an Integer
  • collect(Collectors.toList()) - collects elements of stream

Best way to show a loading/progress indicator?

ProgressDialog has become deprecated since API Level 26 https://developer.android.com/reference/android/app/ProgressDialog.html

I include a ProgressBar in my layout

   <ProgressBar
        android:layout_weight="1"
        android:id="@+id/progressBar_cyclic"
        android:visibility="gone"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:minHeight="40dp"
        android:minWidth="40dp" />

and change its visibility to .GONE | .VISIBLE depending on the use case.

    progressBar_cyclic.visibility = View.VISIBLE

how to import csv data into django models

If you want to use a library, a quick google search for csv and django reveals two libraries - django-csvimport and django-adaptors. Let's read what they have to say about themselves...

  • django-adaptors:

Django adaptor is a tool which allow you to transform easily a CSV/XML file into a python object or a django model instance.

  • django-importcsv:

django-csvimport is a generic importer tool to allow the upload of CSV files for populating data.

The first requires you to write a model to match the csv file, while the second is more of a command-line importer, which is a huge difference in the way you work with them, and each is good for a different type of project.

So which one to use? That depends on which of those will be better suited for your project in the long run.

However, you can also avoid a library altogether, by writing your own django script to import your csv file, something along the lines of (warning, pseudo-code ahead):

# open file & create csvreader
import csv, yada yada yada

# import the relevant model
from myproject.models import Foo

#loop:
for line in csv file:
     line = parse line to a list
     # add some custom validation\parsing for some of the fields

     foo = Foo(fieldname1=line[1], fieldname2=line[2] ... etc. )
     try:
         foo.save()
     except:
         # if the're a problem anywhere, you wanna know about it
         print "there was a problem with line", i 

It's super easy. Hell, you can do it interactively through the django shell if it's a one-time import. Just - figure out what you want to do with your project, how many files do you need to handle and then - if you decide to use a library, try figuring out which one better suits your needs.

A select query selecting a select statement

Not sure if Access supports it, but in most engines (including SQL Server) this is called a correlated subquery and works fine:

SELECT  TypesAndBread.Type, TypesAndBread.TBName,
        (
        SELECT  Count(Sandwiches.[SandwichID]) As SandwichCount
        FROM    Sandwiches
        WHERE   (Type = 'Sandwich Type' AND Sandwiches.Type = TypesAndBread.TBName)
                OR (Type = 'Bread' AND Sandwiches.Bread = TypesAndBread.TBName)
        ) As SandwichCount
FROM    TypesAndBread

This can be made more efficient by indexing Type and Bread and distributing the subqueries over the UNION:

SELECT  [Sandwiches Types].[Sandwich Type] As TBName, "Sandwich Type" As Type,
        (
        SELECT  COUNT(*) As SandwichCount
        FROM    Sandwiches
        WHERE   Sandwiches.Type = [Sandwiches Types].[Sandwich Type]
        )
FROM    [Sandwiches Types]
UNION ALL
SELECT  [Breads].[Bread] As TBName, "Bread" As Type,
        (
        SELECT  COUNT(*) As SandwichCount
        FROM    Sandwiches
        WHERE   Sandwiches.Bread = [Breads].[Bread]
        )
FROM    [Breads]

Creating a config file in PHP

Use an INI file is a flexible and powerful solution! PHP has a native function to handle it properly. For example, it is possible to create an INI file like this:

app.ini

[database]
db_name     = mydatabase
db_user     = myuser
db_password = mypassword

[application]
app_email = [email protected]
app_url   = myapp.com

So the only thing you need to do is call:

$ini = parse_ini_file('app.ini');

Then you can access the definitions easily using the $ini array.

echo $ini['db_name'];     // mydatabase
echo $ini['db_user'];     // myuser
echo $ini['db_password']; // mypassword
echo $ini['app_email'];   // [email protected]

IMPORTANT: For security reasons the INI file must be in a non public folder

Bash scripting, multiple conditions in while loop

Try:

while [ $stats -gt 300 -o $stats -eq 0 ]

[ is a call to test. It is not just for grouping, like parentheses in other languages. Check man [ or man test for more information.

Can a CSS class inherit one or more other classes?

I think this one is a better solution:

[class*=“button-“] {
  /* base button properties */
}
.button-primary { ... }
.button-plain { ... }

Auto-scaling input[type=text] to width of value?

I have a jQuery plugin on GitHub: https://github.com/MartinF/jQuery.Autosize.Input

It mirrors the value of the input, calculates the width and uses it for setting the width of the input.

You can see an live example here: http://jsfiddle.net/mJMpw/2175/

Example of how to use it (because some code is needed when posting a jsfiddle link):

<input type="text" value="" placeholder="Autosize" data-autosize-input='{ "space": 40 }' />

input[type="data-autosize-input"] {
  width: 90px;
  min-width: 90px;
  max-width: 300px;
  transition: width 0.25s;    
}

You just use css to set min/max-width and use a transition on the width if you want a nice effect.

You can specify the space / distance to the end as the value in json notation for the data-autosize-input attribute on the input element.

Of course you can also just initialize it using jQuery

$("selector").autosizeInput();

Is it ok having both Anacondas 2.7 and 3.5 installed in the same time?

Yes, It should be alright to have both versions installed. It's actually pretty much expected nowadays. A lot of stuff is written in 2.7, but 3.5 is becoming the norm. I would recommend updating all your python to 3.5 ASAP, though.

Splitting on last delimiter in Python string?

I just did this for fun

    >>> s = 'a,b,c,d'
    >>> [item[::-1] for item in s[::-1].split(',', 1)][::-1]
    ['a,b,c', 'd']

Caution: Refer to the first comment in below where this answer can go wrong.

How to change Windows 10 interface language on Single Language version

1) Upgrade using windows update or using "media creation tool" http://windows.microsoft.com/en-us/windows-10/media-creation-tool-install

  • if you are using "media creation tool" select "Upgrade this PC now"

When Windows 10 installed check that it is activated.

2) Now as you have activated Windows 10 using "media creation tool" http://windows.microsoft.com/en-us/windows-10/media-creation-tool-install select second option "Create installation media for another PC" here you can select Windows version and its language. Make sure that Windows version is also "Single Language"

3) Boot from you device, USB in my case and install clean Windows in English or any other language you selected.

reference http://bit.ly/1RKmPBs

'python' is not recognized as an internal or external command

From the Python docs, set the PATH like you did as above.

You should arrange for Python’s installation directory to be added to the PATH of every command window as it starts. If you installed Python fairly recently then the command dir C:\py* will probably tell you where it is installed; the usual location is something like C:\Python27. Otherwise you will be reduced to a search of your whole disk

Use Tools ? Find or hit the Search button and look for “python.exe”. Supposing you discover that Python is installed in the C:\Python27 directory (the default at the time of writing), you should make sure that entering the command

Then execute the Python command using the full path name to make sure that works.

How to print in C

The first argument to printf() is always a string value, known as a format control string. This string may be regular text, such as

printf("Hello, World\n"); // \n indicates a newline character

or

char greeting[] = "Hello, World\n";
printf(greeting);

This string may also contain one or more conversion specifiers; these conversion specifiers indicate that additional arguments have been passed to printf(), and they specify how to format those arguments for output. For example, I can change the above to

char greeting[] = "Hello, World";
printf("%s\n", greeting);

The "%s" conversion specifier expects a pointer to a 0-terminated string, and formats it as text.

For signed decimal integer output, use either the "%d" or "%i" conversion specifiers, such as

printf("%d\n", addNumber(a,b));

You can mix regular text with conversion specifiers, like so:

printf("The result of addNumber(%d, %d) is %d\n", a, b, addNumber(a,b));

Note that the conversion specifiers in the control string indicate the number and types of additional parameters. If the number or types of additional arguments passed to printf() don't match the conversion specifiers in the format string then the behavior is undefined. For example:

printf("The result of addNumber(%d, %d) is %d\n", addNumber(a,b));

will result in anything from garbled output to an outright crash.

There are a number of additional flags for conversion specifiers that control field width, precision, padding, justification, and types. Check your handy C reference manual for a complete listing.

Mercurial: how to amend the last commit?

Another solution could be use the uncommit command to exclude specific file from current commit.

hg uncommit [file/directory]

This is very helpful when you want to keep current commit and deselect some files from commit (especially helpful for files/directories have been deleted).

Get the current displaying UIViewController on the screen in AppDelegate.m

This worked for me. I have many targets that have different controllers so previous answers didn't seemed to work.

first you want this inside your AppDelegate class:

var window: UIWindow?

then, in your function

let navigationController = window?.rootViewController as? UINavigationController
if let activeController = navigationController!.visibleViewController {
    if activeController.isKindOfClass( MyViewController )  {
        println("I have found my controller!")    
   }
}

Google OAuth 2 authorization - Error: redirect_uri_mismatch

None of the above solutions worked for me. below did

change authorised Redirect urls to - https://localhost:44377/signin-google

Hope this helps someone.

jQuery.parseJSON throws “Invalid JSON” error due to escaped single quote in JSON

I was trying to save a JSON object from a XHR request into a HTML5 data-* attribute. I tried many of above solutions with no success.

What I finally end up doing was replacing the single quote ' with it code &#39; using a regex after the stringify() method call the following way:

var productToString = JSON.stringify(productObject);
var quoteReplaced = productToString.replace(/'/g, "&#39;");
var anchor = '<a data-product=\'' + quoteReplaced + '\' href=\'#\'>' + productObject.name + '</a>';
// Here you can use the "anchor" variable to update your DOM element.

using setTimeout on promise chain

.then(() => new Promise((resolve) => setTimeout(resolve, 15000)))

UPDATE:

when I need sleep in async function I throw in

await new Promise(resolve => setTimeout(resolve, 1000))

ReferenceError: Invalid left-hand side in assignment

You have to use == to compare (or even ===, if you want to compare types). A single = is for assignment.

if (one == 'rock' && two == 'rock') {
    console.log('Tie! Try again!');
}

Remove all special characters from a string in R?

You need to use regular expressions to identify the unwanted characters. For the most easily readable code, you want the str_replace_all from the stringr package, though gsub from base R works just as well.

The exact regular expression depends upon what you are trying to do. You could just remove those specific characters that you gave in the question, but it's much easier to remove all punctuation characters.

x <- "a1~!@#$%^&*(){}_+:\"<>?,./;'[]-=" #or whatever
str_replace_all(x, "[[:punct:]]", " ")

(The base R equivalent is gsub("[[:punct:]]", " ", x).)

An alternative is to swap out all non-alphanumeric characters.

str_replace_all(x, "[^[:alnum:]]", " ")

Note that the definition of what constitutes a letter or a number or a punctuatution mark varies slightly depending upon your locale, so you may need to experiment a little to get exactly what you want.

Can overridden methods differ in return type?

YES it can be possible

class base {

 base show(){

System.out.println("base class");

return new base();

}
}

class sub extends base{

sub show(){

    System.out.println("sub class");

    return new sub();

 }
}

class inheritance{

 public static void main(String []args) {

        sub obj=new sub();

            obj.show();
 }
}

Image is not showing in browser?

Another random reason for why your images might not show up is because of something called base href="http://..." this can make it so that the images file doesn't work the way it should. Delete that line and you should be good.

How to get an array of specific "key" in multidimensional array without looping

You can also use array_reduce() if you prefer a more functional approach

For instance:

$userNames = array_reduce($users, function ($carry, $user) {
    array_push($carry, $user['name']);
    return $carry;
}, []);

Or if you like to be fancy,

$userNames = [];
array_map(function ($user) use (&$userNames){
    $userNames[]=$user['name'];
}, $users);

This and all the methods above do loop behind the scenes though ;)

How to hide columns in an ASP.NET GridView with auto-generated columns?

In the rowdatabound method for 2nd column

GridView gv = (sender as GridView);
gv.HeaderRow.Cells[2].Visible = false;
e.Row.Cells[2].Visible = false;

CSS @font-face not working in ie

If you're still having troubles with this, here's your solution:

http://www.fontsquirrel.com/fontface/generator

It works far better/faster than any other font-generator and also gives an example for you to use.

Python's "in" set operator

Yes it can mean so, or it can be a simple iterator. For example: Example as iterator:

a=set(['1','2','3'])
for x in a:
 print ('This set contains the value ' + x)

Similarly as a check:

a=set('ILovePython')
if 'I' in a:
 print ('There is an "I" in here')

edited: edited to include sets rather than lists and strings

Properly embedding Youtube video into bootstrap 3.0 page

I use bootstrap 3.x as well and the following code fore responsive youtube video embedding works like charm for me:

.videoWrapperOuter {
  max-width:640px; 
  margin-left:auto;
  margin-right:auto;
}
.videoWrapperInner {
  float: none;
  clear: both;
  width: 100%;
  position: relative;
  padding-bottom: 50%;
  padding-top: 25px;
  height: 0;
}
.videoWrapperInner iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}
<div class="videoWrapperOuter">
  <div class="videoWrapperInner">
    <iframe src="//www.youtube.com/embed/C6-TWRn0k4I" 
      frameborder="0" allowfullscreen></iframe>
  </div>
</div>

I gave a similiar answer on another thread (Shrink a YouTube video to responsive width), but I guess my answers can help here as well.

How can I remove a character from a string using JavaScript?

Just fix your replaceAt:

String.prototype.replaceAt = function(index, charcount) {
  return this.substr(0, index) + this.substr(index + charcount);
}

mystring.replaceAt(4, 1);

I'd call it removeAt instead. :)

How would I extract a single file (or changes to a file) from a git stash?

If the stashed files need to merge with the current version so use the previous ways using diff. Otherwise you might use git pop for unstashing them, git add fileWantToKeep for staging your file, and do a git stash save --keep-index, for stashing everything except what is on stage. Remember that the difference of this way with the previous ones is that it "pops" the file from stash. The previous answers keep it git checkout stash@{0} -- <filename> so it goes according to your needs.

iframe refuses to display

It means that the http server at cw.na1.hgncloud.com send some http headers to tell web browsers like Chrome to allow iframe loading of that page (https://cw.na1.hgncloud.com/crossmatch/) only from a page hosted on the same domain (cw.na1.hgncloud.com) :

Content-Security-Policy: frame-ancestors 'self' https://cw.na1.hgncloud.com
X-Frame-Options: ALLOW-FROM https://cw.na1.hgncloud.com

You should read that :

How to convert IPython notebooks to PDF and HTML?

Other suggested approaches:

  1. Using the 'Print and then select save as pdf.' from your HTML file will result in loss of border edges, highlighting of syntax, trimming of plots etc.

  2. Some other libraries have shown to be broken when it comes to using obsolete versions.

Solution: A better, hassle-free option is to use an online converter which will convert the *.html version of your *.ipynb to *.pdf.

Steps:

  1. First, from your Jupyter notebook interface, convert your *.ipynb to *.html using:

File > Download as > HTML(.html)

  1. Upload the newly created *.html file here and then select the option HTML to PDF.

  2. Your pdf file is now ready for download.

  3. You now have .ipynb, .html and .pdf files

400 BAD request HTTP error code meaning?

Using 400 status codes for any other purpose than indicating that the request is malformed is just plain wrong.

If the request payload contains a byte-sequence that could not be parsed as application/json (if the server expects that dataformat), the appropriate status code is 415:

The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method.

If the request payload is syntactically correct but semantically incorrect, the non-standard 422 response code may be used, or the standard 403 status code:

The server understood the request, but is refusing to fulfill it. Authorization will not help and the request SHOULD NOT be repeated.

How to get current formatted date dd/mm/yyyy in Javascript and append it to an input

To get current date/time in javascript:

var date = new Date();

If you need milliseconds for easy server-side interpretation use

var value = date.getTime();

For formatting dates into a user readable string see this

Then just write to hidden field:

document.getElementById("DATE").value = value;

How to move git repository with all branches from bitbucket to github?

Simplest way of doing it:

git remote rename origin repo_bitbucket

git remote add origin https://github.com/abc/repo.git

git push origin master

Once the push to GitHub is successful, delete the old remote by running:

git remote rm repo_bitbucket

Error: Address already in use while binding socket with address but the port number is shown free by `netstat`

For AF_UNIX you can use call unlink (path); after close() socket in "server" app

List to array conversion to use ravel() function

If all you want is calling ravel on your (nested, I s'pose?) list, you can do that directly, numpy will do the casting for you:

L = [[1,None,3],["The", "quick", object]]
np.ravel(L)
# array([1, None, 3, 'The', 'quick', <class 'object'>], dtype=object)

Also worth mentioning that you needn't go through numpy at all.

What's the difference between faking, mocking, and stubbing?

stub and fake are objects in that they can vary their response based on input parameters. the main difference between them is that a Fake is closer to a real-world implementation than a stub. Stubs contain basically hard-coded responses to an expected request. Let see an example:

public class MyUnitTest {

 @Test
 public void testConcatenate() {
  StubDependency stubDependency = new StubDependency();
  int result = stubDependency.toNumber("one", "two");
  assertEquals("onetwo", result);
 }
}

public class StubDependency() {
 public int toNumber(string param) {
  if (param == “one”) {
   return 1;
  }
  if (param == “two”) {
   return 2;
  }
 }
}

A mock is a step up from fakes and stubs. Mocks provide the same functionality as stubs but are more complex. They can have rules defined for them that dictate in what order methods on their API must be called. Most mocks can track how many times a method was called and can react based on that information. Mocks generally know the context of each call and can react differently in different situations. Because of this, mocks require some knowledge of the class they are mocking. a stub generally cannot track how many times a method was called or in what order a sequence of methods was called. A mock looks like:

public class MockADependency {

 private int ShouldCallTwice;
 private boolean ShouldCallAtEnd;
 private boolean ShouldCallFirst;

 public int StringToInteger(String s) {
  if (s == "abc") {
   return 1;
  }
  if (s == "xyz") {
   return 2;
  }
  return 0;
 }

 public void ShouldCallFirst() {
  if ((ShouldCallTwice > 0) || ShouldCallAtEnd)
   throw new AssertionException("ShouldCallFirst not first thod called");
  ShouldCallFirst = true;
 }

 public int ShouldCallTwice(string s) {
  if (!ShouldCallFirst)
   throw new AssertionException("ShouldCallTwice called before ShouldCallFirst");
  if (ShouldCallAtEnd)
   throw new AssertionException("ShouldCallTwice called after ShouldCallAtEnd");
  if (ShouldCallTwice >= 2)
   throw new AssertionException("ShouldCallTwice called more than twice");
  ShouldCallTwice++;
  return StringToInteger(s);
 }

 public void ShouldCallAtEnd() {
  if (!ShouldCallFirst)
   throw new AssertionException("ShouldCallAtEnd called before ShouldCallFirst");
  if (ShouldCallTwice != 2) throw new AssertionException("ShouldCallTwice not called twice");
  ShouldCallAtEnd = true;
 }

}

"cannot be used as a function error"

Your compiler is right. You can't use the growthRate variable you declared in main as a function.

Maybe you should pick different names for your variables so they don't override function names?

Difference between Static methods and Instance methods

In short, static methods and static variables are class level where as instance methods and instance variables are instance or object level.

This means whenever a instance or object (using new ClassName()) is created, this object will retain its own copy of instace variables. If you have five different objects of same class, you will have five different copies of the instance variables. But the static variables and methods will be the same for all those five objects. If you need something common to be used by each object created make it static. If you need a method which won't need object specific data to work, make it static. The static method will only work with static variable or will return data on the basis of passed arguments.

class A {
    int a;
    int b;

    public void setParameters(int a, int b){
        this.a = a;
        this.b = b;
    }
    public int add(){
        return this.a + this.b;
   }

    public static returnSum(int s1, int s2){
        return (s1 + s2);
    }
}

In the above example, when you call add() as:

A objA = new A();
objA.setParameters(1,2); //since it is instance method, call it using object
objA.add(); // returns 3 

B objB = new B();
objB.setParameters(3,2);
objB.add(); // returns 5

//calling static method
// since it is a class level method, you can call it using class itself
A.returnSum(4,6); //returns 10

class B{
    int s=8;
    int t = 8;
    public addition(int s,int t){
       A.returnSum(s,t);//returns 16
    }
}

In first class, add() will return the sum of data passed by a specific object. But the static method can be used to get the sum from any class not independent if any specific instance or object. Hence, for generic methods which only need arguments to work can be made static to keep it all DRY.

how to inherit Constructor from super class to sub class

Superclass constructor CAN'T be inherited in extended class. Although it can be invoked in extended class constructor's with super() as the first statement.

In a unix shell, how to get yesterday's date into a variable?

ksh93:

dt=${ printf "%(%a %d/%m/%Y)T" yesterday; }

or:

dt=$(printf "%(%a %d/%m/%Y)T" yesterday)

The first one runs in the same process, the second one in a subshell.

Gather multiple sets of columns

This could be done using reshape. It is possible with dplyr though.

  colnames(df) <- gsub("\\.(.{2})$", "_\\1", colnames(df))
  colnames(df)[2] <- "Date"
  res <- reshape(df, idvar=c("id", "Date"), varying=3:8, direction="long", sep="_")
  row.names(res) <- 1:nrow(res)
  
   head(res)
  #  id       Date time       Q3.2       Q3.3
  #1  1 2009-01-01    1  1.3709584  0.4554501
  #2  2 2009-01-02    1 -0.5646982  0.7048373
  #3  3 2009-01-03    1  0.3631284  1.0351035
  #4  4 2009-01-04    1  0.6328626 -0.6089264
  #5  5 2009-01-05    1  0.4042683  0.5049551
  #6  6 2009-01-06    1 -0.1061245 -1.7170087

Or using dplyr

  library(tidyr)
  library(dplyr)
  colnames(df) <- gsub("\\.(.{2})$", "_\\1", colnames(df))

  df %>%
     gather(loop_number, "Q3", starts_with("Q3")) %>% 
     separate(loop_number,c("L1", "L2"), sep="_") %>% 
     spread(L1, Q3) %>%
     select(-L2) %>%
     head()
  #  id       time       Q3.2       Q3.3
  #1  1 2009-01-01  1.3709584  0.4554501
  #2  1 2009-01-01  1.3048697  0.2059986
  #3  1 2009-01-01 -0.3066386  0.3219253
  #4  2 2009-01-02 -0.5646982  0.7048373
  #5  2 2009-01-02  2.2866454 -0.3610573
  #6  2 2009-01-02 -1.7813084 -0.7838389

Update

With new version of tidyr, we can use pivot_longer to reshape multiple columns. (Using the changed column names from gsub above)

library(dplyr)
library(tidyr)
df %>% 
    pivot_longer(cols = starts_with("Q3"), 
          names_to = c(".value", "Q3"), names_sep = "_") %>% 
    select(-Q3)
# A tibble: 30 x 4
#      id time         Q3.2    Q3.3
#   <int> <date>      <dbl>   <dbl>
# 1     1 2009-01-01  0.974  1.47  
# 2     1 2009-01-01 -0.849 -0.513 
# 3     1 2009-01-01  0.894  0.0442
# 4     2 2009-01-02  2.04  -0.553 
# 5     2 2009-01-02  0.694  0.0972
# 6     2 2009-01-02 -1.11   1.85  
# 7     3 2009-01-03  0.413  0.733 
# 8     3 2009-01-03 -0.896 -0.271 
#9     3 2009-01-03  0.509 -0.0512
#10     4 2009-01-04  1.81   0.668 
# … with 20 more rows

NOTE: Values are different because there was no set seed in creating the input dataset

Create Word Document using PHP in Linux

Take a look at PHP COM documents (The comments are helpful) http://us3.php.net/com

Closing a Userform with Unload Me doesn't work

Unload Me only works when its called from userform self. If you want to close a form from another module code (or userform), you need to use the Unload function + userformtoclose name.

I hope its helps

How do I check if a directory exists? "is_dir", "file_exists" or both?

Well instead of checking both, you could do if(stream_resolve_include_path($folder)!==false). It is slower but kills two birds in one shot.

Another option is to simply ignore the E_WARNING, not by using @mkdir(...); (because that would simply waive all possible warnings, not just the directory already exists one), but by registering a specific error handler before doing it:

namespace com\stackoverflow;

set_error_handler(function($errno, $errm) { 
    if (strpos($errm,"exists") === false) throw new \Exception($errm); //or better: create your own FolderCreationException class
});
mkdir($folder);
/* possibly more mkdir instructions, which is when this becomes useful */
restore_error_handler();

Python Key Error=0 - Can't find Dict error in code

The error you're getting is that self.adj doesn't already have a key 0. You're trying to append to a list that doesn't exist yet.

Consider using a defaultdict instead, replacing this line (in __init__):

self.adj = {}

with this:

self.adj = defaultdict(list)

You'll need to import at the top:

from collections import defaultdict

Now rather than raise a KeyError, self.adj[0].append(edge) will create a list automatically to append to.

The HTTP request is unauthorized with client authentication scheme 'Ntlm'. The authentication header received from the server was 'Negotiate,NTLM'

You can eliminate the client from the problem by using wftech, this is an old tool but I have found it useful in diagnosing authentication issues. wfetch allows you to specify NTLM, Negotiate and kerberos, this may well help you better understand your problem. As you are trying to call a service and wfetch knows nothing about WCF, I would suggest applying your endpoint binding (PROVIDERSSoapBinding) to the serviceMetadata then you can do an HTTP GET of the WSDL for the service with the same security settings.

Another option, which may be available to you is to force the server to use NTLM, you can do this by either editing the metabase (IIS 6) and removing the Negotiate setting, more details at http://support.microsoft.com/kb/215383.

If you are using IIS 7.x then the approach is slightly different, details of how to configure the authentication providers are here http://www.iis.net/configreference/system.webserver/security/authentication/windowsauthentication.

I notice that you have blocked out the server address with xxx.xx.xx.xxx, so I'm guessing that this is an IP address rather than a server name, this may cause issues with authentication, so if possible try targeting the machine name.

Sorry that I haven't given you the answer but rather pointers for getting closer to the issue, but I hope it helps.

I'll finish by saying that I have experienced this same issue and my only recourse was to use Kerberos rather than NTLM, don't forget you'll need to register an SPN for the service if you do go down this route.

Why use Select Top 100 Percent?

If there is no ORDER BY clause, then TOP 100 PERCENT is redundant. (As you mention, this was the 'trick' with views)

[Hopefully the optimizer will optimize this away.]

Datatable select with multiple conditions

    protected void FindCsv()
    {
        string strToFind = "2";

        importFolder = @"C:\Documents and Settings\gmendez\Desktop\";

        fileName = "CSVFile.csv";

        connectionString= @"Driver={Microsoft Text Driver (*.txt; *.csv)};Dbq="+importFolder+";Extended Properties=Text;HDR=No;FMT=Delimited";
        conn = new OdbcConnection(connectionString);

        System.Data.Odbc.OdbcDataAdapter  da = new OdbcDataAdapter("select * from [" + fileName + "]", conn);
        DataTable dt = new DataTable();
        da.Fill(dt);

        dt.Columns[0].ColumnName = "id";

        DataRow[] dr = dt.Select("id=" + strToFind);

        Response.Write(dr[0][0].ToString() + dr[0][1].ToString() + dr[0][2].ToString() + dr[0][3].ToString() + dr[0][4].ToString() + dr[0][5].ToString());
    }

Ambiguous overload call to abs(double)

Use fabs() instead of abs(), it's the same but for floats instead of integers.

Delayed function calls

public static class DelayedDelegate
{

    static Timer runDelegates;
    static Dictionary<MethodInvoker, DateTime> delayedDelegates = new Dictionary<MethodInvoker, DateTime>();

    static DelayedDelegate()
    {

        runDelegates = new Timer();
        runDelegates.Interval = 250;
        runDelegates.Tick += RunDelegates;
        runDelegates.Enabled = true;

    }

    public static void Add(MethodInvoker method, int delay)
    {

        delayedDelegates.Add(method, DateTime.Now + TimeSpan.FromSeconds(delay));

    }

    static void RunDelegates(object sender, EventArgs e)
    {

        List<MethodInvoker> removeDelegates = new List<MethodInvoker>();

        foreach (MethodInvoker method in delayedDelegates.Keys)
        {

            if (DateTime.Now >= delayedDelegates[method])
            {
                method();
                removeDelegates.Add(method);
            }

        }

        foreach (MethodInvoker method in removeDelegates)
        {

            delayedDelegates.Remove(method);

        }


    }

}

Usage:

DelayedDelegate.Add(MyMethod,5);

void MyMethod()
{
     MessageBox.Show("5 Seconds Later!");
}

Redirect website after certain amount of time

Use this simple javascript code to redirect page to another page using specific interval of time...

Please add this code into your web site page, which is you want to redirect :

<script type="text/javascript">
(function(){
   setTimeout(function(){
     window.location="http://brightwaay.com/";
   },3000); /* 1000 = 1 second*/
})();
</script>

Http Servlet request lose params from POST body after read it once

So this is basically Lathy's answer BUT updated for newer requirements for ServletInputStream.

Namely (for ServletInputStream), one has to implement:

public abstract boolean isFinished();

public abstract boolean isReady();

public abstract void setReadListener(ReadListener var1);

This is the edited Lathy's object

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class RequestWrapper extends HttpServletRequestWrapper {

    private String _body;

    public RequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        _body = "";
        BufferedReader bufferedReader = request.getReader();
        String line;
        while ((line = bufferedReader.readLine()) != null){
            _body += line;
        }
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {

        CustomServletInputStream kid = new CustomServletInputStream(_body.getBytes());
        return kid;
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }
}

and somewhere (??) I found this (which is a first-class class that deals with the "extra" methods.

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

public class CustomServletInputStream extends ServletInputStream {

    private byte[] myBytes;

    private int lastIndexRetrieved = -1;
    private ReadListener readListener = null;

    public CustomServletInputStream(String s) {
        try {
            this.myBytes = s.getBytes("UTF-8");
        } catch (UnsupportedEncodingException ex) {
            throw new IllegalStateException("JVM did not support UTF-8", ex);
        }
    }

    public CustomServletInputStream(byte[] inputBytes) {
        this.myBytes = inputBytes;
    }

    @Override
    public boolean isFinished() {
        return (lastIndexRetrieved == myBytes.length - 1);
    }

    @Override
    public boolean isReady() {
        // This implementation will never block
        // We also never need to call the readListener from this method, as this method will never return false
        return isFinished();
    }

    @Override
    public void setReadListener(ReadListener readListener) {
        this.readListener = readListener;
        if (!isFinished()) {
            try {
                readListener.onDataAvailable();
            } catch (IOException e) {
                readListener.onError(e);
            }
        } else {
            try {
                readListener.onAllDataRead();
            } catch (IOException e) {
                readListener.onError(e);
            }
        }
    }

    @Override
    public int read() throws IOException {
        int i;
        if (!isFinished()) {
            i = myBytes[lastIndexRetrieved + 1];
            lastIndexRetrieved++;
            if (isFinished() && (readListener != null)) {
                try {
                    readListener.onAllDataRead();
                } catch (IOException ex) {
                    readListener.onError(ex);
                    throw ex;
                }
            }
            return i;
        } else {
            return -1;
        }
    }
};

Ultimately, I was just trying to log the requests. And the above frankensteined together pieces helped me create the below.

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.Principal;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;

//one or the other based on spring version
//import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.boot.web.servlet.error.ErrorAttributes;

import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.ServletRequestAttributes;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.filter.OncePerRequestFilter;


/**
 * A filter which logs web requests that lead to an error in the system.
 */
@Component
public class LogRequestFilter extends OncePerRequestFilter implements Ordered {

    // I tried apache.commons and slf4g loggers.  (one or the other in these next 2 lines of declaration */
    //private final static org.apache.commons.logging.Log logger = org.apache.commons.logging.LogFactory.getLog(LogRequestFilter.class);
    private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(LogRequestFilter.class);

    // put filter at the end of all other filters to make sure we are processing after all others
    private int order = Ordered.LOWEST_PRECEDENCE - 8;
    private ErrorAttributes errorAttributes;

    @Override
    public int getOrder() {
        return order;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
            throws ServletException, IOException {

        String temp = ""; /* for a breakpoint, remove for production/real code */

        /* change to true for easy way to comment out this code, remove this if-check for production/real code */
        if (false) {
            filterChain.doFilter(request, response);
            return;
        }

        /* make a "copy" to avoid issues with body-can-only-read-once issues */
        RequestWrapper reqWrapper = new RequestWrapper(request);

        int status = HttpStatus.INTERNAL_SERVER_ERROR.value();
        // pass through filter chain to do the actual request handling
        filterChain.doFilter(reqWrapper, response);
        status = response.getStatus();

        try {
            Map<String, Object> traceMap = getTrace(reqWrapper, status);
            // body can only be read after the actual request handling was done!
            this.getBodyFromTheRequestCopy(reqWrapper, traceMap);
            
            /* now do something with all the pieces of information gatherered */
            this.logTrace(reqWrapper, traceMap);
        } catch (Exception ex) {
            logger.error("LogRequestFilter FAILED: " + ex.getMessage(), ex);
        }
    }

    private void getBodyFromTheRequestCopy(RequestWrapper rw, Map<String, Object> trace) {
        try {
            if (rw != null) {
                byte[] buf = IOUtils.toByteArray(rw.getInputStream());
                //byte[] buf = rw.getInputStream();
                if (buf.length > 0) {
                    String payloadSlimmed;
                    try {
                        String payload = new String(buf, 0, buf.length, rw.getCharacterEncoding());
                        payloadSlimmed = payload.trim().replaceAll(" +", " ");
                    } catch (UnsupportedEncodingException ex) {
                        payloadSlimmed = "[unknown]";
                    }

                    trace.put("body", payloadSlimmed);
                }
            }
        } catch (IOException ioex) {
            trace.put("body", "EXCEPTION: " + ioex.getMessage());
        }
    }

    private void logTrace(HttpServletRequest request, Map<String, Object> trace) {
        Object method = trace.get("method");
        Object path = trace.get("path");
        Object statusCode = trace.get("statusCode");

        logger.info(String.format("%s %s produced an status code '%s'. Trace: '%s'", method, path, statusCode,
                trace));
    }

    protected Map<String, Object> getTrace(HttpServletRequest request, int status) {
        Throwable exception = (Throwable) request.getAttribute("javax.servlet.error.exception");

        Principal principal = request.getUserPrincipal();

        Map<String, Object> trace = new LinkedHashMap<String, Object>();
        trace.put("method", request.getMethod());
        trace.put("path", request.getRequestURI());
        if (null != principal) {
            trace.put("principal", principal.getName());
        }
        trace.put("query", request.getQueryString());
        trace.put("statusCode", status);

        Enumeration headerNames = request.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            String key = (String) headerNames.nextElement();
            String value = request.getHeader(key);
            trace.put("header:" + key, value);
        }

        if (exception != null && this.errorAttributes != null) {
            trace.put("error", this.errorAttributes
                    .getErrorAttributes((WebRequest) new ServletRequestAttributes(request), true));
        }

        return trace;
    }
}

Please take this code with a grain of salt.

The MOST important "test" is if a POST works with a payload. This is what will expose "double read" issues.

pseudo example code

import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("myroute")
public class MyController {
    @RequestMapping(method = RequestMethod.POST, produces = "application/json")
    @ResponseBody
    public String getSomethingExample(@RequestBody MyCustomObject input) {

        String returnValue = "";

        return returnValue;
    }
}

You can replace "MyCustomObject" with plain ole "Object" if you just want to test.

This answer is frankensteined from several different SOF posts and examples..but it took a while to pull it all together so I hope it helps a future reader.

Please upvote Lathy's answer before mine. I could have not gotten this far without it.

Below is one/some of the exceptions I got while working this out.

getReader() has already been called for this request

Looks like some of the places I "borrowed" from are here:

http://slackspace.de/articles/log-request-body-with-spring-boot/

https://github.com/c0nscience/spring-web-logging/blob/master/src/main/java/org/zalando/springframework/web/logging/LoggingFilter.java

https://howtodoinjava.com/servlets/httpservletrequestwrapper-example-read-request-body/

https://www.oodlestechnologies.com/blogs/How-to-create-duplicate-object-of-httpServletRequest-object

https://github.com/c0nscience/spring-web-logging/blob/master/src/main/java/org/zalando/springframework/web/logging/LoggingFilter.java

January 2021 APPEND.

I have learned the hard way that the above code does NOT work for

x-www-form-urlencoded

Consider the example below:

   @CrossOrigin
    @ResponseBody
    @PostMapping(path = "/mypath", consumes = {MediaType.APPLICATION_FORM_URLENCODED_VALUE})
    public ResponseEntity myMethodName(@RequestParam Map<String, String> parameters
    ) {
        /* DO YOU GET ANY PARAMETERS HERE?  Or are they empty because of logging/auditing filter ?*/
        return new ResponseEntity(HttpStatus.OK);

    }

I had to go through several of the other examples here.

I came up with a "wrapper" that works explicitly for APPLICATION_FORM_URLENCODED_VALUE

import org.apache.commons.io.IOUtils;
import org.springframework.http.MediaType;
import org.springframework.web.util.ContentCachingRequestWrapper;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
 * Makes a "copy" of the HttpRequest so the body can be accessed more than 1 time.
 * WORKS WITH APPLICATION_FORM_URLENCODED_VALUE
 * See : https://stackoverflow.com/questions/44182370/why-do-we-wrap-httpservletrequest-the-api-provides-an-httpservletrequestwrappe/44187955#44187955
 */
public final class AppFormUrlEncodedSpecificContentCachingRequestWrapper extends ContentCachingRequestWrapper {

    public static final String ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED = "ContentType not supported. (Input ContentType(s)=\"%1$s\", Supported ContentType(s)=\"%2$s\")";

    public static final String ERROR_MSG_PERSISTED_CONTENT_CACHING_REQUEST_WRAPPER_CONSTRUCTOR_FAILED = "AppFormUrlEncodedSpecificContentCachingRequestWrapper constructor failed";

    private static final org.slf4j.Logger LOGGER = org.slf4j.LoggerFactory.getLogger(AppFormUrlEncodedSpecificContentCachingRequestWrapper.class);

    private byte[] body;

    private ServletInputStream inputStream;

    public AppFormUrlEncodedSpecificContentCachingRequestWrapper(HttpServletRequest request) {
        super(request);
        super.getParameterMap(); // init cache in ContentCachingRequestWrapper.  THIS IS THE VITAL CALL so that "@RequestParam Map<String, String> parameters" are populated on the REST Controller.  See https://stackoverflow.com/questions/10210645/http-servlet-request-lose-params-from-post-body-after-read-it-once/64924380#64924380

        String contentType = request.getContentType();
        /* EXPLICTLY check for APPLICATION_FORM_URLENCODED_VALUE and allow nothing else */
        if (null == contentType || !contentType.equalsIgnoreCase(MediaType.APPLICATION_FORM_URLENCODED_VALUE)) {
            IllegalArgumentException ioex = new IllegalArgumentException(String.format(ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED, contentType, MediaType.APPLICATION_FORM_URLENCODED_VALUE));
            LOGGER.error(ERROR_MSG_PERSISTED_CONTENT_CACHING_REQUEST_WRAPPER_CONSTRUCTOR_FAILED, ioex);
            throw ioex;
        }

        try {
            loadBody(request);
        } catch (IOException ioex) {
            throw new RuntimeException(ioex);
        }
    }

    private void loadBody(HttpServletRequest request) throws IOException {
        body = IOUtils.toByteArray(request.getInputStream());
        inputStream = new CustomServletInputStream(this.getBody());
    }

    private byte[] getBody() {
        return body;
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        if (inputStream != null) {
            return inputStream;
        }
        return super.getInputStream();
    }
}

Note Andrew Sneck's answer on this same page. It is pretty much this : https://programmersought.com/article/23981013626/

I have not had time to harmonize the two above implementations (my two that is).

So I created a Factory to "choose" from the two:

import org.springframework.http.MediaType;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.IOException;

/**
 * Factory to return different concretes of HttpServletRequestWrapper. APPLICATION_FORM_URLENCODED_VALUE needs a different concrete.
 */
public class HttpServletRequestWrapperFactory {

    public static final String ERROR_MSG_HTTP_SERVLET_REQUEST_WRAPPER_FACTORY_CREATE_HTTP_SERVLET_REQUEST_WRAPPER_FAILED = "HttpServletRequestWrapperFactory createHttpServletRequestWrapper FAILED";

    public static HttpServletRequestWrapper createHttpServletRequestWrapper(final HttpServletRequest request) {
        HttpServletRequestWrapper returnItem = null;

        if (null != request) {
            String contentType = request.getContentType();
            if (null != contentType && contentType.equalsIgnoreCase(MediaType.APPLICATION_FORM_URLENCODED_VALUE)) {
                returnItem = new AppFormUrlEncodedSpecificContentCachingRequestWrapper(request);
            } else {
                try {
                    returnItem = new PersistedBodyRequestWrapper(request);
                } catch (IOException ioex) {
                    throw new RuntimeException(ERROR_MSG_HTTP_SERVLET_REQUEST_WRAPPER_FACTORY_CREATE_HTTP_SERVLET_REQUEST_WRAPPER_FAILED, ioex);
                }
            }
        }

        return returnItem;
    }

}

Below is the "other" one that works with JSON, etc. It is the other concrete that the Factory can output. I put it here so that my Jan 2021 APPEND is consistent..I don't know if the code below is perfect consistent with my original answer:

import org.springframework.http.MediaType;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.Map;

/**
 * Makes a "copy" of the HttpRequest so the body can be accessed more than 1 time.
 * See : https://stackoverflow.com/questions/44182370/why-do-we-wrap-httpservletrequest-the-api-provides-an-httpservletrequestwrappe/44187955#44187955
 * DOES NOT WORK WITH APPLICATION_FORM_URLENCODED_VALUE
 */
public final class PersistedBodyRequestWrapper extends HttpServletRequestWrapper {

    public static final String ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED = "ContentType not supported. (ContentType=\"%1$s\")";

    public static final String ERROR_MSG_PERSISTED_BODY_REQUEST_WRAPPER_CONSTRUCTOR_FAILED = "PersistedBodyRequestWrapper constructor FAILED";

    private static final org.slf4j.Logger LOGGER = org.slf4j.LoggerFactory.getLogger(PersistedBodyRequestWrapper.class);

    private String persistedBody;

    private final Map<String, String[]> parameterMap;

    public PersistedBodyRequestWrapper(final HttpServletRequest request) throws IOException {
        super(request);

        String contentType = request.getContentType();
        /* Allow everything EXCEPT APPLICATION_FORM_URLENCODED_VALUE */
        if (null != contentType && contentType.equalsIgnoreCase(MediaType.APPLICATION_FORM_URLENCODED_VALUE)) {
            IllegalArgumentException ioex = new IllegalArgumentException(String.format(ERROR_MSG_CONTENT_TYPE_NOT_SUPPORTED, MediaType.APPLICATION_FORM_URLENCODED_VALUE));
            LOGGER.error(ERROR_MSG_PERSISTED_BODY_REQUEST_WRAPPER_CONSTRUCTOR_FAILED, ioex);
            throw ioex;
        }

        parameterMap = request.getParameterMap();
        this.persistedBody = "";
        BufferedReader bufferedReader = request.getReader();
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            this.persistedBody += line;
        }
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        CustomServletInputStream csis = new CustomServletInputStream(this.persistedBody.getBytes(StandardCharsets.UTF_8));
        return csis;
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }

    @Override
    public Map<String, String[]> getParameterMap() {
        return this.parameterMap;
    }
}

How to split (chunk) a Ruby array into parts of X elements?

Take a look at Enumerable#each_slice:

foo.each_slice(3).to_a
#=> [["1", "2", "3"], ["4", "5", "6"], ["7", "8", "9"], ["10"]]

Determine when a ViewPager changes pages

ViewPager.setOnPageChangeListener is deprecated now. You now need to use ViewPager.addOnPageChangeListener instead.

for example,

viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

How do you rotate a two dimensional array?

For i:= 0 to X do For j := 0 to X do graphic[j][i] := graphic2[X-i][j]

X is the size of the array the graphic is in.

Playing mp3 song on python

A simple solution:

import webbrowser
webbrowser.open("C:\Users\Public\Music\Sample Music\Kalimba.mp3")

cheers...

Adding new line of data to TextBox

I find this method saves a lot of typing, and prevents a lot of typos.

string nl = "\r\n";

txtOutput.Text = "First line" + nl + "Second line" + nl + "Third line";

Apply style to parent if it has child with css

It's not possible with CSS3. There is a proposed CSS4 selector, $, to do just that, which could look like this (Selecting the li element):

ul $li ul.sub { ... }

See the list of CSS4 Selectors here.

As an alternative, with jQuery, a one-liner you could make use of would be this:

$('ul li:has(ul.sub)').addClass('has_sub');

You could then go ahead and style the li.has_sub in your CSS.

Use of "this" keyword in formal parameters for static methods in C#

This is an extension method. See here for an explanation.

Extension methods allow developers to add new methods to the public contract of an existing CLR type, without having to sub-class it or recompile the original type. Extension Methods help blend the flexibility of "duck typing" support popular within dynamic languages today with the performance and compile-time validation of strongly-typed languages.

Extension Methods enable a variety of useful scenarios, and help make possible the really powerful LINQ query framework... .

it means that you can call

MyClass myClass = new MyClass();
int i = myClass.Foo();

rather than

MyClass myClass = new MyClass();
int i = Foo(myClass);

This allows the construction of fluent interfaces as stated below.

How to get PID of process I've just started within java program?

If portability is not a concern, and you just want to get the pid on Windows without a lot of hassle while using code that is tested and known to work on all modern versions of Windows, you can use kohsuke's winp library. It is also available on Maven Central for easy consumption.

Process process = //...;
WinProcess wp = new WinProcess(process);
int pid = wp.getPid();

intl extension: installing php_intl.dll

I was having trouble getting intl to run using PHP 7.1.7 and PhpStorm on Windows 10. Based on other answers here I could tell it was a PATH/DLL dependency problem but I couldn't seem to find all of the required files even after (re-)installing the Visual C++ Redistributable.

I eventually went searching my C: drive for vcr*.dll and found a copy of vcruntime140.dll in my C:\Program Files\Mozilla Firefox directory. So, in addition to making these changes to php.ini:

extension_dir = "ext"
extension=php_intl.dll

I also set my runtime PATH to ONLY the PHP directory (in my case, C:\Program Files\PHP\7.1.7) and the Firefox directory (above) and it FINALLY worked! I know it needs more than just the vcruntime140.dll but the other required DLLs must be in the FF directory too (there are a few dozen but I didn't bother to figure out which ones are essential).

Procedure expects parameter which was not supplied

In addition to the other answers here, if you've forgotten to put:

cmd.CommandType = CommandType.StoredProcedure;

Then you will also get this error.

how to check if List<T> element contains an item with a Particular Property Value

You don't actually need LINQ for this because List<T> provides a method that does exactly what you want: Find.

Searches for an element that matches the conditions defined by the specified predicate, and returns the first occurrence within the entire List<T>.

Example code:

PricePublicModel result = pricePublicList.Find(x => x.Size == 200);

What's the difference between .NET Core, .NET Framework, and Xamarin?

You can refer in this line - Difference between ASP.NET Core (.NET Core) and ASP.NET Core (.NET Framework)

.NET Framework, .NET Core, Xamarin

Xamarin is not a debate at all. When you want to build mobile (iOS, Android, and Windows Mobile) apps using C#, Xamarin is your only choice.

The .NET Framework supports Windows and Web applications. Today, you can use Windows Forms, WPF, and UWP to build Windows applications in .NET Framework. ASP.NET MVC is used to build Web applications in .NET Framework.

.NET Core is the new open-source and cross-platform framework to build applications for all operating system including Windows, Mac, and Linux. .NET Core supports UWP and ASP.NET Core only. UWP is used to build Windows 10 targets Windows and mobile applications. ASP.NET Core is used to build browser based web applications.

you want more details refer this links
https://blogs.msdn.microsoft.com/dotnet/2016/07/15/net-core-roadmap/ https://docs.microsoft.com/en-us/dotnet/articles/standard/choosing-core-framework-server

Height equal to dynamic width (CSS fluid layout)

It is possible without any Javascript :)

The HTML:

<div class='box'>
    <div class='content'>Aspect ratio of 1:1</div>
</div> 

The CSS:

.box {
    position: relative;
    width:    50%; /* desired width */
}

.box:before {
    content:     "";
    display:     block;
    padding-top: 100%; /* initial ratio of 1:1*/
}

.content {
    position: absolute;
    top:      0;
    left:     0;
    bottom:   0;
    right:    0;
}

/* Other ratios - just apply the desired class to the "box" element */
.ratio2_1:before{
    padding-top: 50%;
}
.ratio1_2:before{
    padding-top: 200%;
}
.ratio4_3:before{
    padding-top: 75%;
}
.ratio16_9:before{
    padding-top: 56.25%;
}

How do you clear a slice in Go?

I was looking into this issue a bit for my own purposes; I had a slice of structs (including some pointers) and I wanted to make sure I got it right; ended up on this thread, and wanted to share my results.

To practice, I did a little go playground: https://play.golang.org/p/9i4gPx3lnY

which evals to this:

package main

import "fmt"

type Blah struct {
    babyKitten int
    kittenSays *string
}

func main() {
    meow := "meow"
    Blahs := []Blah{}
    fmt.Printf("Blahs: %v\n", Blahs)
    Blahs = append(Blahs, Blah{1, &meow})
    fmt.Printf("Blahs: %v\n", Blahs)
    Blahs = append(Blahs, Blah{2, &meow})
    fmt.Printf("Blahs: %v\n", Blahs)
    //fmt.Printf("kittenSays: %v\n", *Blahs[0].kittenSays)
    Blahs = nil
    meow2 := "nyan"
    fmt.Printf("Blahs: %v\n", Blahs)
    Blahs = append(Blahs, Blah{1, &meow2})
    fmt.Printf("Blahs: %v\n", Blahs)
    fmt.Printf("kittenSays: %v\n", *Blahs[0].kittenSays)
}

Running that code as-is will show the same memory address for both "meow" and "meow2" variables as being the same:

Blahs: []
Blahs: [{1 0x1030e0c0}]
Blahs: [{1 0x1030e0c0} {2 0x1030e0c0}]
Blahs: []
Blahs: [{1 0x1030e0f0}]
kittenSays: nyan

which I think confirms that the struct is garbage collected. Oddly enough, uncommenting the commented print line, will yield different memory addresses for the meows:

Blahs: []
Blahs: [{1 0x1030e0c0}]
Blahs: [{1 0x1030e0c0} {2 0x1030e0c0}]
kittenSays: meow
Blahs: []
Blahs: [{1 0x1030e0f8}]
kittenSays: nyan

I think this may be due to the print being deferred in some way (?), but interesting illustration of some memory mgmt behavior, and one more vote for:

[]MyStruct = nil

How to split data into 3 sets (train, validation and test)?

Here is a Python function that splits a Pandas dataframe into train, validation, and test dataframes with stratified sampling. It performs this split by calling scikit-learn's function train_test_split() twice.

import pandas as pd
from sklearn.model_selection import train_test_split

def split_stratified_into_train_val_test(df_input, stratify_colname='y',
                                         frac_train=0.6, frac_val=0.15, frac_test=0.25,
                                         random_state=None):
    '''
    Splits a Pandas dataframe into three subsets (train, val, and test)
    following fractional ratios provided by the user, where each subset is
    stratified by the values in a specific column (that is, each subset has
    the same relative frequency of the values in the column). It performs this
    splitting by running train_test_split() twice.

    Parameters
    ----------
    df_input : Pandas dataframe
        Input dataframe to be split.
    stratify_colname : str
        The name of the column that will be used for stratification. Usually
        this column would be for the label.
    frac_train : float
    frac_val   : float
    frac_test  : float
        The ratios with which the dataframe will be split into train, val, and
        test data. The values should be expressed as float fractions and should
        sum to 1.0.
    random_state : int, None, or RandomStateInstance
        Value to be passed to train_test_split().

    Returns
    -------
    df_train, df_val, df_test :
        Dataframes containing the three splits.
    '''

    if frac_train + frac_val + frac_test != 1.0:
        raise ValueError('fractions %f, %f, %f do not add up to 1.0' % \
                         (frac_train, frac_val, frac_test))

    if stratify_colname not in df_input.columns:
        raise ValueError('%s is not a column in the dataframe' % (stratify_colname))

    X = df_input # Contains all columns.
    y = df_input[[stratify_colname]] # Dataframe of just the column on which to stratify.

    # Split original dataframe into train and temp dataframes.
    df_train, df_temp, y_train, y_temp = train_test_split(X,
                                                          y,
                                                          stratify=y,
                                                          test_size=(1.0 - frac_train),
                                                          random_state=random_state)

    # Split the temp dataframe into val and test dataframes.
    relative_frac_test = frac_test / (frac_val + frac_test)
    df_val, df_test, y_val, y_test = train_test_split(df_temp,
                                                      y_temp,
                                                      stratify=y_temp,
                                                      test_size=relative_frac_test,
                                                      random_state=random_state)

    assert len(df_input) == len(df_train) + len(df_val) + len(df_test)

    return df_train, df_val, df_test

Below is a complete working example.

Consider a dataset that has a label upon which you want to perform the stratification. This label has its own distribution in the original dataset, say 75% foo, 15% bar and 10% baz. Now let's split the dataset into train, validation, and test into subsets using a 60/20/20 ratio, where each split retains the same distribution of the labels. See the illustration below:

enter image description here

Here is the example dataset:

df = pd.DataFrame( { 'A': list(range(0, 100)),
                     'B': list(range(100, 0, -1)),
                     'label': ['foo'] * 75 + ['bar'] * 15 + ['baz'] * 10 } )

df.head()
#    A    B label
# 0  0  100   foo
# 1  1   99   foo
# 2  2   98   foo
# 3  3   97   foo
# 4  4   96   foo

df.shape
# (100, 3)

df.label.value_counts()
# foo    75
# bar    15
# baz    10
# Name: label, dtype: int64

Now, let's call the split_stratified_into_train_val_test() function from above to get train, validation, and test dataframes following a 60/20/20 ratio.

df_train, df_val, df_test = \
    split_stratified_into_train_val_test(df, stratify_colname='label', frac_train=0.60, frac_val=0.20, frac_test=0.20)

The three dataframes df_train, df_val, and df_test contain all the original rows but their sizes will follow the above ratio.

df_train.shape
#(60, 3)

df_val.shape
#(20, 3)

df_test.shape
#(20, 3)

Further, each of the three splits will have the same distribution of the label, namely 75% foo, 15% bar and 10% baz.

df_train.label.value_counts()
# foo    45
# bar     9
# baz     6
# Name: label, dtype: int64

df_val.label.value_counts()
# foo    15
# bar     3
# baz     2
# Name: label, dtype: int64

df_test.label.value_counts()
# foo    15
# bar     3
# baz     2
# Name: label, dtype: int64

How to preventDefault on anchor tags?

Borrowing from tennisgent's answer. I like that you don't have to create a custom directive to add on all the links. However, I couldnt get his to work in IE8. Here's what finally worked for me (using angular 1.0.6).

Notice that 'bind' allows you to use jqLite provided by angular so no need to wrap with full jQuery. Also required the stopPropogation method.

.directive('a', [
    function() {
        return {
            restrict: 'E',
            link: function(scope, elem, attrs) {

                elem.bind('click', function(e){
                    if (attrs.ngClick || attrs.href === '' || attrs.href == '#'){
                        e.preventDefault();
                        e.stopPropagation();
                    }
                })
            }
        };
    }
])

Named regular expression group "(?P<group_name>regexp)": what does "P" stand for?

Python Extension. From the Python Docs:

The solution chosen by the Perl developers was to use (?...) as the extension syntax. ? immediately after a parenthesis was a syntax error because the ? would have nothing to repeat, so this didn’t introduce any compatibility problems. The characters immediately after the ? indicate what extension is being used, so (?=foo) is one thing (a positive lookahead assertion) and (?:foo) is something else (a non-capturing group containing the subexpression foo).

Python supports several of Perl’s extensions and adds an extension syntax to Perl’s extension syntax.If the first character after the question mark is a P, you know that it’s an extension that’s specific to Python

https://docs.python.org/3/howto/regex.html

Meaning of "n:m" and "1:n" in database design

m:n is used to denote a many-to-many relationship (m objects on the other side related to n on the other) while 1:n refers to a one-to-many relationship (1 object on the other side related to n on the other).

Can a main() method of class be invoked from another class in java

If you want to call the main method of another class you can do it this way assuming I understand the question.

public class MyClass {

    public static void main(String[] args) {

        System.out.println("main() method of MyClass");
        OtherClass obj = new OtherClass();
    }
}

class OtherClass {

    public OtherClass() {

        // Call the main() method of MyClass
        String[] arguments = new String[] {"123"};
        MyClass.main(arguments);
    }
}

Character Limit in HTML

use the "maxlength" attribute as others have said.

if you need to put a max character length on a text AREA, you need to turn to Javascript. Take a look here: How to impose maxlength on textArea in HTML using JavaScript

App.settings - the Angular way?

I found that using an APP_INITIALIZER for this doesn't work in situations where other service providers require the configuration to be injected. They can be instantiated before APP_INITIALIZER is run.

I've seen other solutions that use fetch to read a config.json file and provide it using an injection token in a parameter to platformBrowserDynamic() prior to bootstrapping the root module. But fetch isn't supported in all browsers and in particular WebView browsers for the mobile devices I target.

The following is a solution that works for me for both PWA and mobile devices (WebView). Note: I've only tested in Android so far; working from home means I don't have access to a Mac to build.

In main.ts:

import { enableProdMode } from '@angular/core';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';

import { AppModule } from './app/app.module';
import { environment } from './environments/environment';
import { APP_CONFIG } from './app/lib/angular/injection-tokens';

function configListener() {
  try {
    const configuration = JSON.parse(this.responseText);

    // pass config to bootstrap process using an injection token
    platformBrowserDynamic([
      { provide: APP_CONFIG, useValue: configuration }
    ])
      .bootstrapModule(AppModule)
      .catch(err => console.error(err));

  } catch (error) {
    console.error(error);
  }
}

function configFailed(evt) {
  console.error('Error: retrieving config.json');
}

if (environment.production) {
  enableProdMode();
}

const request = new XMLHttpRequest();
request.addEventListener('load', configListener);
request.addEventListener('error', configFailed);
request.open('GET', './assets/config/config.json');
request.send();

This code:

  1. kicks off an async request for the config.json file.
  2. When the request completes, parses the JSON into a Javascript object
  3. provides the value using the APP_CONFIG injection token, prior to bootstrapping.
  4. And finally bootstraps the root module.

APP_CONFIG can then be injected into any additional providers in app-module.ts and it will be defined. For example, I can initialise the FIREBASE_OPTIONS injection token from @angular/fire with the following:

{
      provide: FIREBASE_OPTIONS,
      useFactory: (config: IConfig) => config.firebaseConfig,
      deps: [APP_CONFIG]
}

I find this whole thing a surprisingly difficult (and hacky) thing to do for a very common requirement. Hopefully in the near future there will be a better way, such as, support for async provider factories.

The rest of the code for completeness...

In app/lib/angular/injection-tokens.ts:

import { InjectionToken } from '@angular/core';
import { IConfig } from '../config/config';

export const APP_CONFIG = new InjectionToken<IConfig>('app-config');

and in app/lib/config/config.ts I define the interface for my JSON config file:

export interface IConfig {
    name: string;
    version: string;
    instance: string;
    firebaseConfig: {
        apiKey: string;
        // etc
    }
}

Config is stored in assets/config/config.json:

{
  "name": "my-app",
  "version": "#{Build.BuildNumber}#",
  "instance": "localdev",
  "firebaseConfig": {
    "apiKey": "abcd"
    ...
  }
}

Note: I use an Azure DevOps task to insert Build.BuildNumber and substitute other settings for different deployment environments as it is being deployed.

Command CompileSwift failed with a nonzero exit code in Xcode 10

I had this issue and changing the Compilation Mode setting for the project from Incremental to Whole Module fixed it for me.

enter image description here

Is there a Wikipedia API?

If you want to extract structured data from Wikipedia, you may consider using DbPedia http://dbpedia.org/

It provides means to query data using given criteria using SPARQL and returns data from parsed Wikipedia infobox templates

Here is a quick example how it could be done in .NET http://www.kozlenko.info/blog/2010/07/20/executing-sparql-query-on-wikipedia-in-net/

There are some SPARQL libraries available for multiple platforms to make queries easier

How to recover stashed uncommitted changes

The easy answer to the easy question is git stash apply

Just check out the branch you want your changes on, and then git stash apply. Then use git diff to see the result.

After you're all done with your changes—the apply looks good and you're sure you don't need the stash any more—then use git stash drop to get rid of it.

I always suggest using git stash apply rather than git stash pop. The difference is that apply leaves the stash around for easy re-try of the apply, or for looking at, etc. If pop is able to extract the stash, it will immediately also drop it, and if you the suddenly realize that you wanted to extract it somewhere else (in a different branch), or with --index, or some such, that's not so easy. If you apply, you get to choose when to drop.

It's all pretty minor one way or the other though, and for a newbie to git, it should be about the same. (And you can skip all the rest of this!)


What if you're doing more-advanced or more-complicated stuff?

There are at least three or four different "ways to use git stash", as it were. The above is for "way 1", the "easy way":

  1. You started with a clean branch, were working on some changes, and then realized you were doing them in the wrong branch. You just want to take the changes you have now and "move" them to another branch.

    This is the easy case, described above. Run git stash save (or plain git stash, same thing). Check out the other branch and use git stash apply. This gets git to merge in your earlier changes, using git's rather powerful merge mechanism. Inspect the results carefully (with git diff) to see if you like them, and if you do, use git stash drop to drop the stash. You're done!

  2. You started some changes and stashed them. Then you switched to another branch and started more changes, forgetting that you had the stashed ones.

    Now you want to keep, or even move, these changes, and apply your stash too.

    You can in fact git stash save again, as git stash makes a "stack" of changes. If you do that you have two stashes, one just called stash—but you can also write stash@{0}—and one spelled stash@{1}. Use git stash list (at any time) to see them all. The newest is always the lowest-numbered. When you git stash drop, it drops the newest, and the one that was stash@{1} moves to the top of the stack. If you had even more, the one that was stash@{2} becomes stash@{1}, and so on.

    You can apply and then drop a specific stash, too: git stash apply stash@{2}, and so on. Dropping a specific stash, renumbers only the higher-numbered ones. Again, the one without a number is also stash@{0}.

    If you pile up a lot of stashes, it can get fairly messy (was the stash I wanted stash@{7} or was it stash@{4}? Wait, I just pushed another, now they're 8 and 5?). I personally prefer to transfer these changes to a new branch, because branches have names, and cleanup-attempt-in-December means a lot more to me than stash@{12}. (The git stash command takes an optional save-message, and those can help, but somehow, all my stashes just wind up named WIP on branch.)

  3. (Extra-advanced) You've used git stash save -p, or carefully git add-ed and/or git rm-ed specific bits of your code before running git stash save. You had one version in the stashed index/staging area, and another (different) version in the working tree. You want to preserve all this. So now you use git stash apply --index, and that sometimes fails with:

    Conflicts in index.  Try without --index.
    
  4. You're using git stash save --keep-index in order to test "what will be committed". This one is beyond the scope of this answer; see this other StackOverflow answer instead.

For complicated cases, I recommend starting in a "clean" working directory first, by committing any changes you have now (on a new branch if you like). That way the "somewhere" that you are applying them, has nothing else in it, and you'll just be trying the stashed changes:

git status               # see if there's anything you need to commit
                         # uh oh, there is - let's put it on a new temp branch
git checkout -b temp     # create new temp branch to save stuff
git add ...              # add (and/or remove) stuff as needed
git commit               # save first set of changes

Now you're on a "clean" starting point. Or maybe it goes more like this:

git status               # see if there's anything you need to commit
                         # status says "nothing to commit"
git checkout -b temp     # optional: create new branch for "apply"
git stash apply          # apply stashed changes; see below about --index

The main thing to remember is that the "stash" is a commit, it's just a slightly "funny/weird" commit that's not "on a branch". The apply operation looks at what the commit changed, and tries to repeat it wherever you are now. The stash will still be there (apply keeps it around), so you can look at it more, or decide this was the wrong place to apply it and try again differently, or whatever.


Any time you have a stash, you can use git stash show -p to see a simplified version of what's in the stash. (This simplified version looks only at the "final work tree" changes, not the saved index changes that --index restores separately.) The command git stash apply, without --index, just tries to make those same changes in your work-directory now.

This is true even if you already have some changes. The apply command is happy to apply a stash to a modified working directory (or at least, to try to apply it). You can, for instance, do this:

git stash apply stash      # apply top of stash stack
git stash apply stash@{1}  # and mix in next stash stack entry too

You can choose the "apply" order here, picking out particular stashes to apply in a particular sequence. Note, however, that each time you're basically doing a "git merge", and as the merge documentation warns:

Running git merge with non-trivial uncommitted changes is discouraged: while possible, it may leave you in a state that is hard to back out of in the case of a conflict.

If you start with a clean directory and are just doing several git apply operations, it's easy to back out: use git reset --hard to get back to the clean state, and change your apply operations. (That's why I recommend starting in a clean working directory first, for these complicated cases.)


What about the very worst possible case?

Let's say you're doing Lots Of Advanced Git Stuff, and you've made a stash, and want to git stash apply --index, but it's no longer possible to apply the saved stash with --index, because the branch has diverged too much since the time you saved it.

This is what git stash branch is for.

If you:

  1. check out the exact commit you were on when you did the original stash, then
  2. create a new branch, and finally
  3. git stash apply --index

the attempt to re-create the changes definitely will work. This is what git stash branch newbranch does. (And it then drops the stash since it was successfully applied.)


Some final words about --index (what the heck is it?)

What the --index does is simple to explain, but a bit complicated internally:

  • When you have changes, you have to git add (or "stage") them before commiting.
  • Thus, when you ran git stash, you might have edited both files foo and zorg, but only staged one of those.
  • So when you ask to get the stash back, it might be nice if it git adds the added things and does not git add the non-added things. That is, if you added foo but not zorg back before you did the stash, it might be nice to have that exact same setup. What was staged, should again be staged; what was modified but not staged, should again be modified but not staged.

The --index flag to apply tries to set things up this way. If your work-tree is clean, this usually just works. If your work-tree already has stuff added, though, you can see how there might be some problems here. If you leave out --index, the apply operation does not attempt to preserve the whole staged/unstaged setup. Instead, it just invokes git's merge machinery, using the work-tree commit in the "stash bag". If you don't care about preserving staged/unstaged, leaving out --index makes it a lot easier for git stash apply to do its thing.

How to make a div center align in HTML

I think that the the align="center" aligns the content, so if you wanted to use that method, you would need to use it in a 'wraper' div - a div that just wraps the rest.

text-align is doing a similar sort of thing.

left:50% is ignored unless you set the div's position to be something like relative or absolute.

The generally accepted methods is to use the following properties

width:500px; // this can be what ever unit you want, you just have to define it
margin-left:auto;
margin-right:auto;

the margins being auto means they grow/shrink to match the browser window (or parent div)

UPDATE

Thanks to Meo for poiting this out, if you wanted to you could save time and use the short hand propery for the margin.

margin:0 auto;

this defines the top and bottom as 0 (as it is zero it does not matter about lack of units) and the left and right get defined as 'auto' You can then, if you wan't override say the top margin as you would with any other CSS rules.

How do I get the classes of all columns in a data frame?

One option is to use lapply and class. For example:

> foo <- data.frame(c("a", "b"), c(1, 2))
> names(foo) <- c("SomeFactor", "SomeNumeric")
> lapply(foo, class)
$SomeFactor
[1] "factor"

$SomeNumeric
[1] "numeric"

Another option is str:

> str(foo)
'data.frame':   2 obs. of  2 variables:
 $ SomeFactor : Factor w/ 2 levels "a","b": 1 2
 $ SomeNumeric: num  1 2

#ifdef in C#

C# does have a preprocessor. It works just slightly differently than that of C++ and C.

Here is a MSDN links - the section on all preprocessor directives.

How to unset (remove) a collection element after fetching it?

You would want to use ->forget()

$collection->forget($key);

Link to the forget method documentation

Bootstrap throws Uncaught Error: Bootstrap's JavaScript requires jQuery

You need to add JQuery before adding bootstrap-

<!-- JQuery Core JavaScript -->
<script src="lib/js/jquery.min.js"></script>

<!-- Bootstrap Core JavaScript -->
<script src="lib/js/bootstrap.min.js"></script>

How do I concatenate two text files in PowerShell?

You could use the Add-Content cmdlet. Maybe it is a little faster than the other solutions, because I don't retrieve the content of the first file.

gc .\file2.txt| Add-Content -Path .\file1.txt

Identifier is undefined

From the update 2 and after narrowing down the problem scope, we can easily find that there is a brace missing at the end of the function addWord. The compiler will never explicitly identify such a syntax error. instead, it will assume that the missing function definition located in some other object file. The linker will complain about it and hence directly will be categorized under one of the broad the error phrases which is identifier is undefined. Reasonably, because with the current syntax the next function definition (in this case is ac_search) will be included under the addWord scope. Hence, it is not a global function anymore. And that is why compiler will not see this function outside addWord and will throw this error message stating that there is no such a function. A very good elaboration about the compiler and the linker can be found in this article

Remove characters from a String in Java

Strings in java are immutable. That means you need to create a new string or overwrite your old string to achieve the desired affect:

id = id.replace(".xml", "");

Oracle: how to add minutes to a timestamp?

Based on what you're asking for, you want the HH24:MI format for to_char.

What is the preferred syntax for defining enums in JavaScript?

export const ButtonType = Object.freeze({ 
   DEFAULT: 'default', 
   BIG: 'big', 
   SMALL: 'small'
})

source: https://medium.com/@idanlevi2/enum-in-javascript-5f2ff500f149

How do I make JavaScript beep?

<html>
<head>
    <script src='https://surikov.github.io/webaudiofont/npm/dist/WebAudioFontPlayer.js'></script>
    <script src='https://surikov.github.io/webaudiofontdata/sound/0000_JCLive_sf2_file.js'></script>
    <script>
        var selectedPreset=_tone_0000_JCLive_sf2_file;
        var AudioContextFunc = window.AudioContext || window.webkitAudioContext;
        var audioContext = new AudioContextFunc();
        var player=new WebAudioFontPlayer();
        player.loader.decodeAfterLoading(audioContext, '_tone_0000_JCLive_sf2_file');
    </script>
</head>
<body>
    <p><a href="#" onmousedown="player.queueWaveTable(audioContext, audioContext.destination, selectedPreset, 0, 55, 3.5);">Play a note</a></p>
    <hr/>
    <p><a href="https://github.com/surikov/webaudiofont">source</a></p>
</body>

listen here https://jsbin.com/lamidog/1/edit?html,output

Passing just a type as a parameter in C#

You can use an argument of type Type - iow, pass typeof(int). You can also use generics for a (probably more efficient) approach.

Which is fastest? SELECT SQL_CALC_FOUND_ROWS FROM `table`, or SELECT COUNT(*)

It depends. See the MySQL Performance Blog post on this subject: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?

Just a quick summary: Peter says that it depends on your indexes and other factors. Many of the comments to the post seem to say that SQL_CALC_FOUND_ROWS is almost always slower - sometimes up to 10x slower - than running two queries.

How to import keras from tf.keras in Tensorflow?

this worked for me in tensorflow==1.4.0

from tensorflow.python import keras

What is the "right" way to iterate through an array in Ruby?

The other answers are just fine, but I wanted to point out one other peripheral thing: Arrays are ordered, whereas Hashes are not in 1.8. (In Ruby 1.9, Hashes are ordered by insertion order of keys.) So it wouldn't make sense prior to 1.9 to iterate over a Hash in the same way/sequence as Arrays, which have always had a definite ordering. I don't know what the default order is for PHP associative arrays (apparently my google fu isn't strong enough to figure that out, either), but I don't know how you can consider regular PHP arrays and PHP associative arrays to be "the same" in this context, since the order for associative arrays seems undefined.

As such, the Ruby way seems more clear and intuitive to me. :)

Can I set state inside a useEffect hook

? 1. Can I set state inside a useEffect hook?

In principle, you can set state freely where you need it - including inside useEffect and even during rendering. Just make sure to avoid infinite loops by settting Hook deps properly and/or state conditionally.


? 2. Lets say I have some state that is dependent on some other state. Is it appropriate to create a hook that observes A and sets B inside the useEffect hook?

You just described the classic use case for useReducer:

useReducer is usually preferable to useState when you have complex state logic that involves multiple sub-values or when the next state depends on the previous one. (React docs)

When setting a state variable depends on the current value of another state variable, you might want to try replacing them both with useReducer. [...] When you find yourself writing setSomething(something => ...), it’s a good time to consider using a reducer instead. (Dan Abramov, Overreacted blog)

_x000D_
_x000D_
let MyComponent = () => {_x000D_
  let [state, dispatch] = useReducer(reducer, { a: 1, b: 2 });_x000D_
_x000D_
  useEffect(() => {_x000D_
    console.log("Some effect with B");_x000D_
  }, [state.b]);_x000D_
_x000D_
  return (_x000D_
    <div>_x000D_
      <p>A: {state.a}, B: {state.b}</p>_x000D_
      <button onClick={() => dispatch({ type: "SET_A", payload: 5 })}>_x000D_
        Set A to 5 and Check B_x000D_
      </button>_x000D_
      <button onClick={() => dispatch({ type: "INCREMENT_B" })}>_x000D_
        Increment B_x000D_
      </button>_x000D_
    </div>_x000D_
  );_x000D_
};_x000D_
_x000D_
// B depends on A. If B >= A, then reset B to 1._x000D_
function reducer(state, { type, payload }) {_x000D_
  const someCondition = state.b >= state.a;_x000D_
_x000D_
  if (type === "SET_A")_x000D_
    return someCondition ? { a: payload, b: 1 } : { ...state, a: payload };_x000D_
  else if (type === "INCREMENT_B") return { ...state, b: state.b + 1 };_x000D_
  return state;_x000D_
}_x000D_
_x000D_
ReactDOM.render(<MyComponent />, document.getElementById("root"));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.0/umd/react.production.min.js" integrity="sha256-32Gmw5rBDXyMjg/73FgpukoTZdMrxuYW7tj8adbN8z4=" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.0/umd/react-dom.production.min.js" integrity="sha256-bjQ42ac3EN0GqK40pC9gGi/YixvKyZ24qMP/9HiGW7w=" crossorigin="anonymous"></script>_x000D_
<div id="root"></div>_x000D_
<script>var { useReducer, useEffect } = React</script>
_x000D_
_x000D_
_x000D_


? 3. Will the effects cascade such that, when I click the button, the first effect will fire, causing b to change, causing the second effect to fire, before the next render?

useEffect always runs after the render is committed and DOM changes are applied. The first effect fires, changes b and causes a re-render. After this render has completed, second effect will run due to b changes.

_x000D_
_x000D_
let MyComponent = props => {_x000D_
  console.log("render");_x000D_
  let [a, setA] = useState(1);_x000D_
  let [b, setB] = useState(2);_x000D_
_x000D_
  let isFirstRender = useRef(true);_x000D_
_x000D_
  useEffect(() => {_x000D_
    console.log("useEffect a, value:", a);_x000D_
    if (isFirstRender.current) isFirstRender.current = false;_x000D_
    else setB(3);_x000D_
    return () => {_x000D_
      console.log("unmount useEffect a, value:", a);_x000D_
    };_x000D_
  }, [a]);_x000D_
  useEffect(() => {_x000D_
    console.log("useEffect b, value:", b);_x000D_
    return () => {_x000D_
      console.log("unmount useEffect b, value:", b);_x000D_
    };_x000D_
  }, [b]);_x000D_
_x000D_
  return (_x000D_
    <div>_x000D_
      <p>a: {a}, b: {b}</p>_x000D_
      <button_x000D_
        onClick={() => {_x000D_
          console.log("Clicked!");_x000D_
          setA(5);_x000D_
        }}_x000D_
      >_x000D_
        click me_x000D_
      </button>_x000D_
    </div>_x000D_
  );_x000D_
};_x000D_
_x000D_
ReactDOM.render(<MyComponent />, document.getElementById("root"));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.0/umd/react.production.min.js" integrity="sha256-32Gmw5rBDXyMjg/73FgpukoTZdMrxuYW7tj8adbN8z4=" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.0/umd/react-dom.production.min.js" integrity="sha256-bjQ42ac3EN0GqK40pC9gGi/YixvKyZ24qMP/9HiGW7w=" crossorigin="anonymous"></script>_x000D_
<div id="root"></div>_x000D_
<script>var { useReducer, useEffect, useState, useRef } = React</script>
_x000D_
_x000D_
_x000D_


? 4. Are there any performance downsides to structuring code like this?

Yes. By wrapping the state change of b in a separate useEffect for a, the browser has an additional layout/paint phase - these effects are potentially visible for the user. If there is no way you want give useReducer a try, you could change b state together with a directly:

_x000D_
_x000D_
let MyComponent = () => {_x000D_
  console.log("render");_x000D_
  let [a, setA] = useState(1);_x000D_
  let [b, setB] = useState(2);_x000D_
_x000D_
  useEffect(() => {_x000D_
    console.log("useEffect b, value:", b);_x000D_
    return () => {_x000D_
      console.log("unmount useEffect b, value:", b);_x000D_
    };_x000D_
  }, [b]);_x000D_
_x000D_
  const handleClick = () => {_x000D_
    console.log("Clicked!");_x000D_
    setA(5);_x000D_
    b >= 5 ? setB(1) : setB(b + 1);_x000D_
  };_x000D_
_x000D_
  return (_x000D_
    <div>_x000D_
      <p>_x000D_
        a: {a}, b: {b}_x000D_
      </p>_x000D_
      <button onClick={handleClick}>click me</button>_x000D_
    </div>_x000D_
  );_x000D_
};_x000D_
_x000D_
ReactDOM.render(<MyComponent />, document.getElementById("root"));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.0/umd/react.production.min.js" integrity="sha256-32Gmw5rBDXyMjg/73FgpukoTZdMrxuYW7tj8adbN8z4=" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.0/umd/react-dom.production.min.js" integrity="sha256-bjQ42ac3EN0GqK40pC9gGi/YixvKyZ24qMP/9HiGW7w=" crossorigin="anonymous"></script>_x000D_
<div id="root"></div>_x000D_
<script>var { useReducer, useEffect, useState, useRef } = React</script>
_x000D_
_x000D_
_x000D_

<embed> vs. <object>

Answer updated for 2020:

Both <object> and <embed> are included in the WHAT-WG HTML Living Standard (Sept 2020).


<object>

The object element can represent an external resource, which, depending on the type of the resource, will either be treated as an image, as a child browsing context, or as an external resource to be processed by a plugin.


<embed>

The embed element provides an integration point for an external (typically non-HTML) application or interactive content.


Are there advantages/disadvantages to using one tag vs. the other?

The opinion of Mozilla Developer Network (MDN) appears (albeit fairly subtly) to very marginally favour <object> over <embed> but overwhelmingly, MDN, wants to recommend that wherever you can, you avoid embedding external content entirely.

[...] you are unlikely to use these elements very much — Applets haven't been used for years, Flash is no longer very popular, due to a number of reasons (see The case against plugins, below), PDFs tend to be better linked to than embedded, and other content such as images and video have much better, easier elements to handle those. Plugins and these embedding methods are really a legacy technology, and we are mainly mentioning them in case you come across them in certain circumstances like intranets, or enterprise projects.

Once upon a time, plugins were indispensable on the Web. Remember the days when you had to install Adobe Flash Player just to watch a movie online? And then you constantly got annoying alerts about updating Flash Player and your Java Runtime Environment. Web technologies have since grown much more robust, and those days are over. For virtually all applications, it's time to stop delivering content that depends on plugins and start taking advantage of Web technologies instead.

Source: https://developer.mozilla.org/en-US/docs/Learn/HTML/Multimedia_and_embedding/Other_embedding_technologies#The_%3Cembed%3E_and_%3Cobject%3E_elements

How to use multiple @RequestMapping annotations in spring?

The shortest way is: @RequestMapping({"", "/", "welcome"})

Although you can also do:

  • @RequestMapping(value={"", "/", "welcome"})
  • @RequestMapping(path={"", "/", "welcome"})

MySQL - UPDATE multiple rows with different values in one query

To Extend on @Trevedhek answer,

In case the update has to be done with non-unique keys, 4 queries will be need

NOTE: This is not transaction-safe

This can be done using a temp table.

Step 1: Create a temp table keys and the columns you want to update

CREATE TEMPORARY TABLE  temp_table_users
(
    cod_user varchar(50)
    , date varchar(50)
    , user_rol varchar(50)
    ,  cod_office varchar(50)
) ENGINE=MEMORY

Step 2: Insert the values into the temp table

Step 3: Update the original table

UPDATE table_users t1
JOIN temp_table_users tt1 using(user_rol,cod_office)
SET 
t1.cod_office = tt1.cod_office
t1.date = tt1.date

Step 4: Drop the temp table

One command to create a directory and file inside it linux command

For this purpose, you can create your own function. For example:

$ echo 'mkfile() { mkdir -p "$(dirname "$1")" && touch "$1" ;  }' >> ~/.bashrc
$ source ~/.bashrc
$ mkfile ./fldr1/fldr2/file.txt

Explanation:

  • Insert the function to the end of ~/.bashrc file using the echo command
  • The -p flag is for creating the nested folders, such as fldr2
  • Update the ~/.bashrc file with the source command
  • Use the mkfile function to create the file

How unique is UUID?

For UUID4 I make it that there are approximately as many IDs as there are grains of sand in a cube-shaped box with sides 360,000km long. That's a box with sides ~2 1/2 times longer than Jupiter's diameter.

Working so someone can tell me if I've messed up units:

  • volume of grain of sand 0.00947mm^3 (Guardian)
  • UUID4 has 122 random bits -> 5.3e36 possible values (wikipedia)
  • volume of that many grains of sand = 5.0191e34 mm^3 or 5.0191e+25m^3
  • side length of cubic box with that volume = 3.69E8m or 369,000km
  • diameter of Jupiter: 139,820km (google)

Changing the URL in react-router v4 without using Redirect or Link

I'm using this to redirect with React Router v4:

this.props.history.push('/foo');

Hope it work for you ;)

Adding local .aar files to Gradle build using "flatDirs" is not working

This line includes all aar and jar files from libs folder:

implementation fileTree(include: ['*.jar', '*.aar'], dir: 'libs/')

ERROR Error: Uncaught (in promise), Cannot match any routes. URL Segment

When you use routerLink like this, then you need to pass the value of the route it should go to. But when you use routerLink with the property binding syntax, like this: [routerLink], then it should be assigned a name of the property the value of which will be the route it should navigate the user to.

So to fix your issue, replace this routerLink="['/about']" with routerLink="/about" in your HTML.

There were other places where you used property binding syntax when it wasn't really required. I've fixed it and you can simply use the template syntax below:

<nav class="main-nav>
  <ul 
    class="main-nav__list" 
    ng-sticky 
    addClass="main-sticky-link" 
    [ngClass]="ref.click ? 'Navbar__ToggleShow' : ''">
    <li class="main-nav__item" routerLinkActive="active">
      <a class="main-nav__link" routerLink="/">Home</a>
    </li>
    <li class="main-nav__item" routerLinkActive="active"> 
      <a class="main-nav__link" routerLink="/about">About us</a>
    </li>
  </ul>
</nav>

It also needs to know where exactly should it load the template for the Component corresponding to the route it has reached. So for that, don't forget to add a <router-outlet></router-outlet>, either in your template provided above or in a parent component.

There's another issue with your AppRoutingModule. You need to export the RouterModule from there so that it is available to your AppModule when it imports it. To fix that, export it from your AppRoutingModule by adding it to the exports array.

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { RouterModule, Routes } from '@angular/router';
import { MainLayoutComponent } from './layout/main-layout/main-layout.component';
import { AboutComponent } from './components/about/about.component';
import { WhatwedoComponent } from './components/whatwedo/whatwedo.component';
import { FooterComponent } from './components/footer/footer.component';
import { ProjectsComponent } from './components/projects/projects.component';
const routes: Routes = [
  { path: 'about', component: AboutComponent },
  { path: 'what', component: WhatwedoComponent },
  { path: 'contacts', component: FooterComponent },
  { path: 'projects', component: ProjectsComponent},
];

@NgModule({
  imports: [
    CommonModule,
    RouterModule.forRoot(routes),
  ],
  exports: [RouterModule],
  declarations: []
})
export class AppRoutingModule { }

How can I make a time delay in Python?

Delays can be also implemented by using the following methods.

The first method:

import time
time.sleep(5) # Delay for 5 seconds.

The second method to delay would be using the implicit wait method:

 driver.implicitly_wait(5)

The third method is more useful when you have to wait until a particular action is completed or until an element is found:

self.wait.until(EC.presence_of_element_located((By.ID, 'UserName'))

Bash: Echoing a echo command with a variable in bash

echo "echo "we are now going to work with ${ser}" " >> $servfile

Escape all " within quotes with \. Do this with variables like \$servicetest too:

echo "echo \"we are now going to work with \${ser}\" " >> $servfile    
echo "read -p \"Please enter a service: \" ser " >> $servfile
echo "if [ \$servicetest > /dev/null ];then " >> $servfile

Android ADB doesn't see device

Some of these answers are pretty old, so maybe it's changed in recent times, but I had similar issues and I solved it by:

  1. Loading the USB drivers for the device - Samsung S6
  2. Enable Developer tools on the phone.
  3. On the device, go to Settings - Applications - Development - Check USB Debugging
  4. Reboot O/S (Windows 7 - 64bit)
  5. Open Visual Studio

I think it was step 3 that had me stumped for a while. I'd enabled developer tools, but I didn't specifically enable the "USB Debugging" but.

Count number of tables in Oracle

Select count(*) FROM all_tables where owner='schema_name'

java.lang.ClassCastException

To avoid x !instance of Long prob Add

<property name="openjpa.Compatibility" value="StrictIdentityValues=false"/>

in your persistence.xml

Calling a function from a string in C#

Yes. You can use reflection. Something like this:

Type thisType = this.GetType();
MethodInfo theMethod = thisType.GetMethod(TheCommandString);
theMethod.Invoke(this, userParameters);

How to open Android Device Monitor in latest Android Studio 3.1

To start the standalone Device Monitor application, enter the following on the command line in the android-sdk/tools/ directory:

monitor

But remember Most of the Android Device Monitor componenets are deprecated after 3.0 For detail info visit this link

Android Device Monitor and its features are deprecated after 3.0

Python check if list items are integers?

You can use exceptional handling as str.digit will only work for integers and can fail for something like this too:

>>> str.isdigit(' 1')
False

Using a generator function:

def solve(lis):                                        
    for x in lis:
        try:
            yield float(x)
        except ValueError:    
            pass

>>> mylist = ['1','orange','2','3','4','apple', '1.5', '2.6']
>>> list(solve(mylist))                                    
[1.0, 2.0, 3.0, 4.0, 1.5, 2.6]   #returns converted values

or may be you wanted this:

def solve(lis):
    for x in lis:
        try:
            float(x)
            return True
        except:
            return False
...         
>>> mylist = ['1','orange','2','3','4','apple', '1.5', '2.6']
>>> [x for x in mylist if solve(x)]
['1', '2', '3', '4', '1.5', '2.6']

or using ast.literal_eval, this will work for all types of numbers:

>>> from ast import literal_eval
>>> def solve(lis):
    for x in lis:
        try:
            literal_eval(x)
            return True
        except ValueError:   
             return False
...         
>>> mylist=['1','orange','2','3','4','apple', '1.5', '2.6', '1+0j']
>>> [x for x in mylist if solve(x)]                               
['1', '2', '3', '4', '1.5', '2.6', '1+0j']

What are the differences between JSON and JSONP?

JSONP allows you to specify a callback function that is passed your JSON object. This allows you to bypass the same origin policy and load JSON from an external server into the JavaScript on your webpage.

Changing background color of selected item in recyclerview

I made this implementation in kotlin I thing is not very efficient but works ivIsSelected is a ImageView that represent in my case a check mark

var selectedItems = mutableListOf<Int>(-1)

override fun onBindViewHolder(holder: ContactViewHolder, position: Int) {
    // holder.setData(ContactViewModel, position)  // I'm passing this to the ViewHolder
    holder.itemView.setBackgroundColor(Color.WHITE)   
    holder.itemView.ivIsSelected.visibility = INVISIBLE
    selectedItems.forEach {
        if (it == position) {
            holder.itemView.setBackgroundColor(Color.argb(45, 0, 255, 43))
            holder.itemView.ivIsSelected.visibility = VISIBLE
        }
    }

    holder.itemView.setOnClickListener { it ->
        it.setBackgroundColor(Color.BLUE)  
        selectedItems.add(position)
        selectedItems.forEach { selectedItem ->  // this forEach is required to refresh all the list
            notifyItemChanged(selectedItem)
        }

    }
}

How to list all properties of a PowerShell object

You can also use:

Get-WmiObject -Class "Win32_computersystem" | Select *

This will show the same result as Format-List * used in the other answers here.

Create Log File in Powershell

I believe this is the simplest way of putting all what it is on the screen into a file. It is a native PS CmdLet so you don't have to change anything in yout script

Start-Transcript -Path Computer.log

Write-Host "everything will end up in Computer.log"

Stop-Transcript

How to serialize SqlAlchemy result to JSON?

install simplejson by pip install simplejson and the create a class

class Serialise(object):

    def _asdict(self):
        """
        Serialization logic for converting entities using flask's jsonify

        :return: An ordered dictionary
        :rtype: :class:`collections.OrderedDict`
        """

        result = OrderedDict()
        # Get the columns
        for key in self.__mapper__.c.keys():
            if isinstance(getattr(self, key), datetime):
                result["x"] = getattr(self, key).timestamp() * 1000
                result["timestamp"] = result["x"]
            else:
                result[key] = getattr(self, key)

        return result

and inherit this class to every orm classes so that this _asdict function gets registered to every ORM class and boom. And use jsonify anywhere

Error Code: 1005. Can't create table '...' (errno: 150)

Sometimes it is due to the master table is dropped (maybe by disabling foreign_key_checks), but the foreign key CONSTRAINT still exists in other tables. In my case I had dropped the table and tried to recreate it, but it was throwing the same error for me.

So try dropping all the foreign key CONSTRAINTs from all the tables if there are any and then update or create the table.

How do you remove Subversion control for a folder?

On Linux, this will work:

  find . -iname ".svn" -print0 | xargs -0 rm -r

Check if an HTML input element is empty or has no value entered by user

getElementById will return false if the element was not found in the DOM.

var el = document.getElementById("customx");
if (el !== null && el.value === "")
{
  //The element was found and the value is empty.
}

Generate Java classes from .XSD files...?

JAXB Limitation.

I worked on JAXB, as per my opinion its a nice way of dealing with data between XML and Java objects. The Positive sides are its proven and better in performance and control over the data during runtime. With a good usage of built tools or scripts it will takes away lot of coding efforts.

I found the configuration part is not a straight away task, and spent hours in getting the development environment setup.

However I dropped this solution due to a silly limitation I faced. My XML Schema Definition ( XSD ) has a attribute/element with name "value" and that I have to use XSD as it is. This very little constraint forced the my binding step XJC failed with a Error "Property 'Value' already used."

This is due to the JAXB implementation, the binding process tries to create Java objects out of XSD by adding few attributes to each class and one of them being a value attribute. When it processed my XSD it complained that there is already a property with that name.

base 64 encode and decode a string in angular (2+)

Use the btoa() function to encode:

_x000D_
_x000D_
console.log(btoa("password")); // cGFzc3dvcmQ=
_x000D_
_x000D_
_x000D_

To decode, you can use the atob() function:

_x000D_
_x000D_
console.log(atob("cGFzc3dvcmQ=")); // password
_x000D_
_x000D_
_x000D_

Custom CSS Scrollbar for Firefox

Year 2020 this works

/* Thin Scrollbar */
:root{
  scrollbar-color: rgb(210,210,210) rgb(46,54,69) !important;
  scrollbar-width: thin !important;
}

https://github.com/Aris-t2/CustomCSSforFx/issues/160

iterating through json object javascript

Here is my recursive approach:

function visit(object) {
    if (isIterable(object)) {
        forEachIn(object, function (accessor, child) {
            visit(child);
        });
    }
    else {
        var value = object;
        console.log(value);
    }
}

function forEachIn(iterable, functionRef) {
    for (var accessor in iterable) {
        functionRef(accessor, iterable[accessor]);
    }
}

function isIterable(element) {
    return isArray(element) || isObject(element);
}

function isArray(element) {
    return element.constructor == Array;
}

function isObject(element) {
    return element.constructor == Object;
}

How to throw an exception in C?

C doesn't have exceptions.

There are various hacky implementations that try to do it (one example at: http://adomas.org/excc/).

failed to open stream: No such file or directory in

include() needs a full file path, relative to the file system's root directory.

This should work:

 include_once("C:/xampp/htdocs/PoliticalForum/headerSite.php");

What size should TabBar images be?

According to the Apple Human Interface Guidelines:

@1x : about 25 x 25 (max: 48 x 32)

@2x : about 50 x 50 (max: 96 x 64)

@3x : about 75 x 75 (max: 144 x 96)

IIS - can't access page by ip address instead of localhost

So I had this same problem with WSUS and it turned out that IIS 8.5 was not binding to my ipv4 ip address, but was binding to ipv6 address. when I accessed it via localhost:8580 it would translate it to the ipv6 localhost address, and thus would work. Accessing it via ip was a no go. I had to manually bind the address using netsh, then it worked right away. bloody annoying.

Steps:

  1. Open command prompt as administrator
  2. Type the following:

netsh http add iplisten ipaddress (IPADDRESSOFYOURSERVER)

that's it. You should get:

IP address successfully added

I found the commands here https://serverfault.com/questions/123796/get-iis-7-5-to-listen-on-ipv6

jQuery datepicker set selected date, on the fly

This works for me:

$("#dateselector").datepicker("option", "defaultDate", new Date(2008,9,3));

Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship

You will have to use the fluent API to do this.

Try adding the following to your DbContext:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{   
    modelBuilder.Entity<User>()
        .HasOptional(a => a.UserDetail)
        .WithOptionalDependent()
        .WillCascadeOnDelete(true);
}

How do I add button on each row in datatable?

Take a Look.

$(document).ready(function () {     
        $('#datatable').DataTable({
            columns: [
                { 'data': 'ID' },
                { 'data': 'AuthorName' },
                { 'data': 'TotalBook' },
                { 'data': 'DateofBirth' },
                { 'data': 'OccupationEN' },   
                { 'data': null, title: 'Action', wrap: true, "render": function (item) { return '<div class="btn-group"> <button type="button" onclick="set_value(' + item.ID + ')" value="0" class="btn btn-warning" data-toggle="modal" data-target="#myModal">View</button></div>' } },
            ],            
            bServerSide: true,
            sAjaxSource: 'EmployeeDataHandler.ashx'           
        });       
    });

SQL Server - An expression of non-boolean type specified in a context where a condition is expected, near 'RETURN'

Your problem might be here:

OR
                        (
                            SELECT m.ResourceNo FROM JobMember m
                            JOIN JobTask t ON t.JobTaskNo = m.JobTaskNo
                            WHERE t.TaskManagerNo = @UserResourceNo
                            OR
                            t.AlternateTaskManagerNo = @UserResourceNo
                        )

try changing to

OR r.ResourceNo IN
                        (
                            SELECT m.ResourceNo FROM JobMember m
                            JOIN JobTask t ON t.JobTaskNo = m.JobTaskNo
                            WHERE t.TaskManagerNo = @UserResourceNo
                            OR
                            t.AlternateTaskManagerNo = @UserResourceNo
                        )

ListView with OnItemClickListener

lv.setOnItemClickListener( new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView < ? > parent, View view,
                            int position, long id) {
        // TODO Auto-generated method stub

    }
} );

Java system properties and environment variables

I think the difference between the two boils down to access. Environment variables are accessible by any process and Java system properties are only accessible by the process they are added to.

Also as Bohemian stated, env variables are set in the OS (however they 'can' be set through Java) and system properties are passed as command line options or set via setProperty().

C++, How to determine if a Windows Process is running?

You can never check and see if a process is running, you can only check to see if a process was running at some point in the recent past. A process is an entity that is not controlled by your application and can exit at any moment in time. There is no way to guaranteed that a process will not exit in between the check to see if it's running and the corresponding action.

The best approach is to just do the action required and catch the exception that would be thrown if the process was not running.

VBA array sort function?

Natural Number (Strings) Quick Sort

Just to pile onto the topic. Normally, if you sort strings with numbers you'll get something like this:

    Text1
    Text10
    Text100
    Text11
    Text2
    Text20

But you really want it to recognize the numerical values and be sorted like

    Text1
    Text2
    Text10
    Text11
    Text20
    Text100

Here's how to do it...

Note:

  • I stole the Quick Sort from the internet a long time ago, not sure where now...
  • I translated the CompareNaturalNum function which was originally written in C from the internet as well.
  • Difference from other Q-Sorts: I don't swap the values if the BottomTemp = TopTemp

Natural Number Quick Sort

Public Sub QuickSortNaturalNum(strArray() As String, intBottom As Integer, intTop As Integer)
Dim strPivot As String, strTemp As String
Dim intBottomTemp As Integer, intTopTemp As Integer

    intBottomTemp = intBottom
    intTopTemp = intTop

    strPivot = strArray((intBottom + intTop) \ 2)

    Do While (intBottomTemp <= intTopTemp)
        ' < comparison of the values is a descending sort
        Do While (CompareNaturalNum(strArray(intBottomTemp), strPivot) < 0 And intBottomTemp < intTop)
            intBottomTemp = intBottomTemp + 1
        Loop
        Do While (CompareNaturalNum(strPivot, strArray(intTopTemp)) < 0 And intTopTemp > intBottom) '
            intTopTemp = intTopTemp - 1
        Loop
        If intBottomTemp < intTopTemp Then
            strTemp = strArray(intBottomTemp)
            strArray(intBottomTemp) = strArray(intTopTemp)
            strArray(intTopTemp) = strTemp
        End If
        If intBottomTemp <= intTopTemp Then
            intBottomTemp = intBottomTemp + 1
            intTopTemp = intTopTemp - 1
        End If
    Loop

    'the function calls itself until everything is in good order
    If (intBottom < intTopTemp) Then QuickSortNaturalNum strArray, intBottom, intTopTemp
    If (intBottomTemp < intTop) Then QuickSortNaturalNum strArray, intBottomTemp, intTop
End Sub

Natural Number Compare(Used in Quick Sort)

Function CompareNaturalNum(string1 As Variant, string2 As Variant) As Integer
'string1 is less than string2 -1
'string1 is equal to string2 0
'string1 is greater than string2 1
Dim n1 As Long, n2 As Long
Dim iPosOrig1 As Integer, iPosOrig2 As Integer
Dim iPos1 As Integer, iPos2 As Integer
Dim nOffset1 As Integer, nOffset2 As Integer

    If Not (IsNull(string1) Or IsNull(string2)) Then
        iPos1 = 1
        iPos2 = 1
        Do While iPos1 <= Len(string1)
            If iPos2 > Len(string2) Then
                CompareNaturalNum = 1
                Exit Function
            End If
            If isDigit(string1, iPos1) Then
                If Not isDigit(string2, iPos2) Then
                    CompareNaturalNum = -1
                    Exit Function
                End If
                iPosOrig1 = iPos1
                iPosOrig2 = iPos2
                Do While isDigit(string1, iPos1)
                    iPos1 = iPos1 + 1
                Loop

                Do While isDigit(string2, iPos2)
                    iPos2 = iPos2 + 1
                Loop

                nOffset1 = (iPos1 - iPosOrig1)
                nOffset2 = (iPos2 - iPosOrig2)

                n1 = Val(Mid(string1, iPosOrig1, nOffset1))
                n2 = Val(Mid(string2, iPosOrig2, nOffset2))

                If (n1 < n2) Then
                    CompareNaturalNum = -1
                    Exit Function
                ElseIf (n1 > n2) Then
                    CompareNaturalNum = 1
                    Exit Function
                End If

                ' front padded zeros (put 01 before 1)
                If (n1 = n2) Then
                    If (nOffset1 > nOffset2) Then
                        CompareNaturalNum = -1
                        Exit Function
                    ElseIf (nOffset1 < nOffset2) Then
                        CompareNaturalNum = 1
                        Exit Function
                    End If
                End If
            ElseIf isDigit(string2, iPos2) Then
                CompareNaturalNum = 1
                Exit Function
            Else
                If (Mid(string1, iPos1, 1) < Mid(string2, iPos2, 1)) Then
                    CompareNaturalNum = -1
                    Exit Function
                ElseIf (Mid(string1, iPos1, 1) > Mid(string2, iPos2, 1)) Then
                    CompareNaturalNum = 1
                    Exit Function
                End If

                iPos1 = iPos1 + 1
                iPos2 = iPos2 + 1
            End If
        Loop
        ' Everything was the same so far, check if Len(string2) > Len(String1)
        ' If so, then string1 < string2
        If Len(string2) > Len(string1) Then
            CompareNaturalNum = -1
            Exit Function
        End If
    Else
        If IsNull(string1) And Not IsNull(string2) Then
            CompareNaturalNum = -1
            Exit Function
        ElseIf IsNull(string1) And IsNull(string2) Then
            CompareNaturalNum = 0
            Exit Function
        ElseIf Not IsNull(string1) And IsNull(string2) Then
            CompareNaturalNum = 1
            Exit Function
        End If
    End If
End Function

isDigit(Used in CompareNaturalNum)

Function isDigit(ByVal str As String, pos As Integer) As Boolean
Dim iCode As Integer
    If pos <= Len(str) Then
        iCode = Asc(Mid(str, pos, 1))
        If iCode >= 48 And iCode <= 57 Then isDigit = True
    End If
End Function

Count unique values using pandas groupby

I think you can use SeriesGroupBy.nunique:

print (df.groupby('param')['group'].nunique())
param
a    2
b    1
Name: group, dtype: int64

Another solution with unique, then create new df by DataFrame.from_records, reshape to Series by stack and last value_counts:

a = df[df.param.notnull()].groupby('group')['param'].unique()
print (pd.DataFrame.from_records(a.values.tolist()).stack().value_counts())
a    2
b    1
dtype: int64

Javascript loop through object array?

You can use forEach method to iterate over array of objects.

data.messages.forEach(function(message){
    console.log(message)
});

Refer: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach

What is the difference between "SMS Push" and "WAP Push"?

An SMS Push is a message to tell the terminal to initiate the session. This happens because you can't initiate an IP session simply because you don't know the IP Adress of the mobile terminal. Mostly used to send a few lines of data to end recipient, to the effect of sending information, or reminding of events.

WAP Push is an SMS within the header of which is included a link to a WAP address. On receiving a WAP Push, the compatible mobile handset automatically gives the user the option to access the WAP content on his handset. The WAP Push directs the end-user to a WAP address where content is stored ready for viewing or downloading onto the handset. This wap address may be a page or a WAP site.

The user may “take action” by using a developer-defined soft-key to immediately activate an application to accomplish a specific task, such as downloading a picture, making a purchase, or responding to a marketing offer.

Fixed positioned div within a relative parent div

This is possible if you move the fixed <div> using margins and not positions:

#wrap{ position:absolute;left:100px;top:100px; }
#fixed{ 
   position:fixed;
   width:10px;
   height:10px;
   background-color:#333;
   margin-left:200px;
   margin-top:200px;
}

And this HTML:

<div id="wrap">
   <div id="fixed"></div>
</div>

Play around with this jsfiddle.

get value from DataTable

It looks like you have accidentally declared DataType as an array rather than as a string.

Change line 3 to:

Dim DataType As String = myTableData.Rows(i).Item(1)

That should work.

Python, how to check if a result set is empty?

I had issues with rowcount always returning -1 no matter what solution I tried.

I found the following a good replacement to check for a null result.

c.execute("SELECT * FROM users WHERE id=?", (id_num,))
row = c.fetchone()
if row == None:
   print("There are no results for this query")

How to change the server port from 3000?

You can change it inside bs-config.json file as mentioned in the docs https://github.com/johnpapa/lite-server#custom-configuration

For example,

{
  "port": 8000,
  "files": ["./src/**/*.{html,htm,css,js}"],
  "server": { "baseDir": "./src" }
}

Remote JMX connection

I have the same issue and I change any hostname that matches the local host name to 0.0.0.0, it seems to work after I do that.

Difference between CLOCK_REALTIME and CLOCK_MONOTONIC?

CLOCK_REALTIME represents the machine's best-guess as to the current wall-clock, time-of-day time. As Ignacio and MarkR say, this means that CLOCK_REALTIME can jump forwards and backwards as the system time-of-day clock is changed, including by NTP.

CLOCK_MONOTONIC represents the absolute elapsed wall-clock time since some arbitrary, fixed point in the past. It isn't affected by changes in the system time-of-day clock.

If you want to compute the elapsed time between two events observed on the one machine without an intervening reboot, CLOCK_MONOTONIC is the best option.

Note that on Linux, CLOCK_MONOTONIC does not measure time spent in suspend, although by the POSIX definition it should. You can use the Linux-specific CLOCK_BOOTTIME for a monotonic clock that keeps running during suspend.

How to remove "onclick" with JQuery?

What if onclick event is not directly on element, but from parent element? This should work:

$(".noclick").attr('onclick','').unbind('click');
$(".noclick").click(function(e){
    e.preventDefault();
    e.stopPropagation();
    return false;
});

Warning: date_format() expects parameter 1 to be DateTime

I've tried sean662's 3rd solution and worked with now() function stored in an INSERT sql an then it's value in the date_create() function. After that the variable is then passed through the date_format() function and you can have the date order that you like.

IF EXISTS condition not working with PLSQL

Unfortunately PL/SQL doesn't have IF EXISTS operator like SQL Server. But you can do something like this:

begin
  for x in ( select count(*) cnt
               from dual 
              where exists (
                select 1 from courseoffering co
                  join co_enrolment ce on ce.co_id = co.co_id
                 where ce.s_regno = 403 
                   and ce.coe_completionstatus = 'C' 
                   and co.c_id = 803 ) )
  loop
        if ( x.cnt = 1 ) 
        then
           dbms_output.put_line('exists');
        else 
           dbms_output.put_line('does not exist');
        end if;
  end loop;
end;
/

yum error "Cannot retrieve metalink for repository: epel. Please verify its path and try again" updating ContextBroker

For my case commenting out mirrorlist and uncomenting entries with baseurl din't work. I noticed the problem was with the https iniside the .repofedora files. I solved it by going in /etc/yum.repository.d and replacing all https with http in different .repo files. That worked!!

PHP array delete by value (not key)

With PHP 7.4 using arrow functions:

$messages = array_filter($messages, fn ($m) => $m != $del_val);

To keep it a non-associative array wrap it with array_values():

$messages = array_values(array_filter($messages, fn ($m) => $m != $del_val));

What is the Python equivalent for a case/switch statement?

The direct replacement is if/elif/else.

However, in many cases there are better ways to do it in Python. See "Replacements for switch statement in Python?".

What are the lesser known but useful data structures?

Tries, also known as prefix-trees or crit-bit trees, have existed for over 40 years but are still relatively unknown. A very cool use of tries is described in "TRASH - A dynamic LC-trie and hash data structure", which combines a trie with a hash function.

Switch statement for string matching in JavaScript

var token = 'spo';

switch(token){
    case ( (token.match(/spo/) )? token : undefined ) :
       console.log('MATCHED')    
    break;;
    default:
       console.log('NO MATCH')
    break;;
}


--> If the match is made the ternary expression returns the original token
----> The original token is evaluated by case

--> If the match is not made the ternary returns undefined
----> Case evaluates the token against undefined which hopefully your token is not.

The ternary test can be anything for instance in your case

( !!~ base_url_string.indexOf('xxx.dev.yyy.com') )? xxx.dev.yyy.com : undefined 

===========================================

(token.match(/spo/) )? token : undefined ) 

is a ternary expression.

The test in this case is token.match(/spo/) which states the match the string held in token against the regex expression /spo/ ( which is the literal string spo in this case ).

If the expression and the string match it results in true and returns token ( which is the string the switch statement is operating on ).

Obviously token === token so the switch statement is matched and the case evaluated

It is easier to understand if you look at it in layers and understand that the turnery test is evaluated "BEFORE" the switch statement so that the switch statement only sees the results of the test.

How can I increase the size of a bootstrap button?

bootstrap comes with clas btn-lg http://getbootstrap.com/components/#btn-dropdowns-sizing

<div class="btn btn-default btn-block">
  Active
</div>

but if you want to have the button of the width of your column / container add btn-block

<div class="btn btn-default btn-lg">
      Active
    </div>

However this will expand to 100% so make surt ethat you will wrap your button in certain amount of columns e.g. then you know its always stays 3 columns until xs screen

<div class="col-sm-3">
             <div class="btn btn-default btn-block">
          Active
            </div>
        </div>

How do you rename a MongoDB database?

I tried doing.

db.copyDatabase('DB_toBeRenamed','Db_newName','host') 

and came to know that it has been Deprecated by the mongo community although it created the backup or renamed DB.

WARNING: db.copyDatabase is deprecated. See http://dochub.mongodb.org/core/copydb-clone-deprecation
{
        "note" : "Support for the copydb command has been deprecated. See 
        http://dochub.mongodb.org/core/copydb-clone-deprecation",
        "ok" : 1
}

So not convinced with the above approach I had to take Dump of local using below command

mongodump --host --db DB_TobeRenamed --out E://FileName/

connected to Db.

use DB_TobeRenamed

then

db.dropDatabase()

then restored the DB with command.

mongorestore -host hostName -d Db_NewName E://FileName/

Hibernate Criteria Join with 3 Tables

The fetch mode only says that the association must be fetched. If you want to add restrictions on an associated entity, you must create an alias, or a subcriteria. I generally prefer using aliases, but YMMV:

Criteria c = session.createCriteria(Dokument.class, "dokument");
c.createAlias("dokument.role", "role"); // inner join by default
c.createAlias("role.contact", "contact");
c.add(Restrictions.eq("contact.lastName", "Test"));
return c.list();

This is of course well explained in the Hibernate reference manual, and the javadoc for Criteria even has examples. Read the documentation: it has plenty of useful information.

Using GZIP compression with Spring Boot/MVC/JavaConfig with RESTful

To enable GZIP compression, you need to modify the configuration of the embedded Tomcat instance. To do so, you declare a EmbeddedServletContainerCustomizer bean in your Java configuration and then register a TomcatConnectorCustomizer with it.

For example:

@Bean
public EmbeddedServletContainerCustomizer servletContainerCustomizer() {
    return new EmbeddedServletContainerCustomizer() {
        @Override
        public void customize(ConfigurableEmbeddedServletContainerFactory factory) {
            ((TomcatEmbeddedServletContainerFactory) factory).addConnectorCustomizers(new TomcatConnectorCustomizer() {
                @Override
                public void customize(Connector connector) {
                    AbstractHttp11Protocol httpProtocol = (AbstractHttp11Protocol) connector.getProtocolHandler();
                    httpProtocol.setCompression("on");
                    httpProtocol.setCompressionMinSize(64);
                }
            });
        }
    };
}

See the Tomcat documentation for more details on the various compression configuration options that are available.

You say that you want to selectively enable compression. Depending on your selection criteria, then the above approach may be sufficient. It enables you to control compression by the request's user-agent, the response's size, and the response's mime type.

If this doesn't meet your needs then I believe you will have to perform the compression in your controller and return a byte[] response with a gzip content-encoding header.

Getting the current date in SQL Server?

As you are using SQL Server 2008, go with Martin's answer.

If you find yourself needing to do it in SQL Server 2005 where you don't have access to the Date column type, I'd use:

SELECT DATEADD(DAY, DATEDIFF(DAY, 0, GETDATE()), 0)

SQLFiddle

Why can't I reference System.ComponentModel.DataAnnotations?

You have to reference the assembly in which this namespace is defined (it is not referenced by default in the visual studio templates). Open your reference manager and add a reference to the System.ComponentModel.DataAnnotations assembly (Solution explorer -> Add reference -> Select .Net tab -> select System.ComponentModel.DataAnnotations from the list)

2D array values C++

int iArray[2][2] = {{1, 2}, {3, 4}};

Think of a 2D array as an array of arrays.

How to create a md5 hash of a string in C?

I don't know this particular library, but I've used very similar calls. So this is my best guess:

unsigned char digest[16];
const char* string = "Hello World";
struct MD5Context context;
MD5Init(&context);
MD5Update(&context, string, strlen(string));
MD5Final(digest, &context);

This will give you back an integer representation of the hash. You can then turn this into a hex representation if you want to pass it around as a string.

char md5string[33];
for(int i = 0; i < 16; ++i)
    sprintf(&md5string[i*2], "%02x", (unsigned int)digest[i]);

Check if a row exists using old mysql_* API

If you just want to compare only one row with $lactureName then use following

function checkLectureStatus($lectureName)
{
 $con = connectvar();
 mysql_select_db("mydatabase", $con);
 $result = mysql_query("SELECT * FROM preditors_assigned WHERE lecture_name='$lectureName'");
  if(mysql_num_rows($result) > 0)
  {
         mysql_close($con);
         return "Assigned";
  }
  else
  {
        mysql_close($con);
        return "Available";
  }
}

How to use ADB Shell when Multiple Devices are connected? Fails with "error: more than one device and emulator"

The best way to run shell on any particular device is to use:

adb -s << emulator UDID >> shell

For Example:
adb -s emulator-5554 shell

Installing SciPy and NumPy using pip

This worked for me on Ubuntu 14.04:

sudo apt-get install libblas-dev liblapack-dev libatlas-base-dev gfortran
pip install scipy

Using Pipes within ngModel on INPUT Elements in Angular

You can't use Template expression operators(pipe, save navigator) within template statement:

(ngModelChange)="Template statements"

(ngModelChange)="item.value | useMyPipeToFormatThatValue=$event"

https://angular.io/guide/template-syntax#template-statements

Like template expressions, template statements use a language that looks like JavaScript. The template statement parser differs from the template expression parser and specifically supports both basic assignment (=) and chaining expressions (with ; or ,).

However, certain JavaScript syntax is not allowed:

  • new
  • increment and decrement operators, ++ and --
  • operator assignment, such as += and -=
  • the bitwise operators | and &
  • the template expression operators

So you should write it as follows:

<input [ngModel]="item.value | useMyPipeToFormatThatValue" 
      (ngModelChange)="item.value=$event" name="inputField" type="text" />

Plunker Example

How do I get an OAuth 2.0 authentication token in C#

You may use the following code to get the bearer token.

private string GetBearerToken()
{
    var client = new RestClient("https://service.endpoint.com");
    client.Authenticator = new HttpBasicAuthenticator("abc", "123");
    var request = new RestRequest("api/oauth2/token", Method.POST);
    request.AddHeader("content-type", "application/json");
    request.AddParameter("application/json", "{ \"grant_type\":\"client_credentials\" }", 
    ParameterType.RequestBody);
    var responseJson = _client.Execute(request).Content;
    var token = JsonConvert.DeserializeObject<Dictionary<string, object>>(responseJson)["access_token"].ToString();
    if(token.Length == 0)
    {
        throw new AuthenticationException("API authentication failed.");
    }
    return token;
}

How do I use ROW_NUMBER()?

May not be related to the question here. But I found it could be useful when using ROW_NUMBER -

SELECT *,
ROW_NUMBER() OVER (ORDER BY (SELECT 100)) AS Any_ID 
FROM #Any_Table

Get time difference between two dates in seconds

time difference between now and 10 minutes later using momentjs

let start_time = moment().format('YYYY-MM-DD HH:mm:ss');
let next_time = moment().add(10, 'm').format('YYYY-MM-DD HH:mm:ss');

let diff_milliseconds = Date.parse(next_time) - Date.parse(star_time);
let diff_seconds = diff_milliseconds * 1000;

How to embed a .mov file in HTML?

Well, if you don't want to do the work yourself (object elements aren't really all that hard), you could always use Mike Alsup's Media plugin: http://jquery.malsup.com/media/

How to get Node.JS Express to listen only on localhost?

Thanks for the info, think I see the problem. This is a bug in hive-go that only shows up when you add a host. The last lines of it are:

app.listen(3001);
console.log("... port %d in %s mode", app.address().port, app.settings.env);

When you add the host on the first line, it is crashing when it calls app.address().port.

The problem is the potentially asynchronous nature of .listen(). Really it should be doing that console.log call inside a callback passed to listen. When you add the host, it tries to do a DNS lookup, which is async. So when that line tries to fetch the address, there isn't one yet because the DNS request is running, so it crashes.

Try this:

app.listen(3001, 'localhost', function() {
  console.log("... port %d in %s mode", app.address().port, app.settings.env);
});

How to display both icon and title of action inside ActionBar?

You can create actions with text in 2 ways:

1- From XML:

<item android:id="@id/resource_name"
      android:title="text"
      android:icon="@drawable/drawable_resource_name"
      android:showAsAction="withText" />

When inflating the menu, you should call getSupportMenuInflater() since you are using ActionBarSherlock.

2- Programmatically:

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuItem item = menu.add(Menu.NONE, ID, POSITION, TEXT);
    item.setIcon(R.drawable.drawable_resource_name);
    item.setShowAsAction(MenuItem.SHOW_AS_ACTION_WITH_TEXT);

    return true;
}

Make sure you import com.actionbarsherlock.view.Menu and com.actionbarsherlock.view.MenuItem.

Parsing time string in Python

Here's a stdlib solution that supports a variable utc offset in the input time string:

>>> from email.utils import parsedate_tz, mktime_tz
>>> from datetime import datetime, timedelta
>>> timestamp = mktime_tz(parsedate_tz('Tue May 08 15:14:45 +0800 2012'))
>>> utc_time = datetime(1970, 1, 1) + timedelta(seconds=timestamp)
>>> utc_time
datetime.datetime(2012, 5, 8, 7, 14, 45)

Entity Framework 5 Updating a Record

Just to add to the list of options. You can also grab the object from the database, and use an auto mapping tool like Auto Mapper to update the parts of the record you want to change..

Jquery to open Bootstrap v3 modal of remote url

In bootstrap-3.3.7.js you will see the following code.

if (this.options.remote) {
  this.$element
    .find('.modal-content')
    .load(this.options.remote, $.proxy(function () {
      this.$element.trigger('loaded.bs.modal')
    }, this))
}

So the bootstrap is going to replace the remote content into <div class="modal-content"> element. This is the default behavior by framework. So the problem is in your remote content itself, it should contain <div class="modal-header">, <div class="modal-body">, <div class="modal-footer"> by design.

C# - Simplest way to remove first occurrence of a substring from another string

int index = sourceString.IndexOf(removeString);
string cleanPath = (index < 0)
    ? sourceString
    : sourceString.Remove(index, removeString.Length);

Adding simple legend to plot in R

Take a look at ?legend and try this:

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

enter image description here

Using scanner.nextLine()

Rather than placing an extra scanner.nextLine() each time you want to read something, since it seems you want to accept each input on a new line, you might want to instead changing the delimiter to actually match only newlines (instead of any whitespace, as is the default)

import java.util.Scanner;

class ScannerTest {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        scanner.useDelimiter("\\n");

        System.out.print("Enter an index: ");
        int index = scanner.nextInt();

        System.out.print("Enter a sentence: ");
        String sentence = scanner.next();

        System.out.println("\nYour sentence: " + sentence);
        System.out.println("Your index: " + index);
    }
}

Thus, to read a line of input, you only need scanner.next() that has the same behavior delimiter-wise of next{Int, Double, ...}

The difference with the "nextLine() every time" approach, is that the latter will accept, as an index also <space>3, 3<space> and 3<space>whatever while the former only accepts 3 on a line on its own

Converting string to byte array in C#

Encoding.Default should not be used...

@Randall's answer uses Encoding.Default, however Microsoft raises a warning against it:

Different computers can use different encodings as the default, and the default encoding can change on a single computer. If you use the Default encoding to encode and decode data streamed between computers or retrieved at different times on the same computer, it may translate that data incorrectly. In addition, the encoding returned by the Default property uses best-fit fallback to map unsupported characters to characters supported by the code page. For these reasons, using the default encoding is not recommended. To ensure that encoded bytes are decoded properly, you should use a Unicode encoding, such as UTF8Encoding or UnicodeEncoding. You could also use a higher-level protocol to ensure that the same format is used for encoding and decoding.

To check what the default encoding is, use Encoding.Default.WindowsCodePage (1250 in my case - and sadly, there is no predefined class of CP1250 encoding, but the object could be retrieved as Encoding.GetEncoding(1250)).

...UTF-8 encoding should be used instead...

Encoding.ASCII is 7bit, so it doesn't work either, in my case:

byte[] pass = Encoding.ASCII.GetBytes("šarže");
Console.WriteLine(Encoding.ASCII.GetString(pass)); // ?ar?e

Following Microsoft's recommendation:

var utf8 = new UTF8Encoding();
byte[] pass = utf8.GetBytes("šarže");
Console.WriteLine(utf8.GetString(pass)); // šarže

Encoding.UTF8 recommended by others is an instance uf UTF-8 encoding and can be also used directly or as

var utf8 = Encoding.UTF8 as UTF8Encoding;

...but it is not used always

Default encoding is misleading: .NET uses UTF-8 everywhere (including strings hardcoded in the source code), but Windows actually uses 2 other non-UTF8 non-standard defaults: ANSI codepage (for GUI apps before .NET) and OEM codepage (aka DOS standard). These differs from country to country (for instance, Windows Czech edition uses CP1250 and CP852) and are oftentimes hardcoded in windows API libraries. So if you just set UTF-8 to console by chcp 65001 (as .NET implicitly does and pretends it is the default) and run some localized command (like ping), it works in English version, but you get tofu text in Czech Republic.

Let me share my real world experience: I created WinForms application customizing git scripts for teachers. The output is obtained on the background anynchronously by a process described by Microsoft as (bold text added by me):

The word "shell" in this context (UseShellExecute) refers to a graphical shell (ANSI CP) (similar to the Windows shell) rather than command shells (for example, bash or sh) (OEM CP) and lets users launch graphical applications or open documents (with messed output in non-US environment).

So effectively GUI defaults to UTF-8, process defaults to CP1250 and console defaults to 852. So the output is in 852 interpreted as UTF-8 interpreted as CP1250. I got tofu text from which I could not deduce the original codepage due to the double conversion. I was pulling my hair for a week to figure out to explicitly set UTF-8 for process script and convert the output from CP1250 to UTF-8 in the main thread. Now it works here in the Eastern Europe, but Western Europe Windows uses 1252. ANSI CP is not determined easily as many commands like systeminfo are also localized and other methods differs from version to version: in such environment displaying national characters reliably is almost unfeasible.

So until the half of 21st century, please DO NOT use any "Default Codepage" and set it explicitly (to UTF-8 if possible).

How to pass all arguments passed to my bash script to a function of mine?

The $@ variable expands to all command-line parameters separated by spaces. Here is an example.

abc "$@"

When using $@, you should (almost) always put it in double-quotes to avoid misparsing of arguments containing spaces or wildcards (see below). This works for multiple arguments. It is also portable to all POSIX-compliant shells.

It is also worth nothing that $0 (generally the script's name or path) is not in $@.

The Bash Reference Manual Special Parameters Section says that $@ expands to the positional parameters starting from one. When the expansion occurs within double quotes, each parameter expands to a separate word. That is "$@" is equivalent to "$1" "$2" "$3"....

Passing some arguments:

If you want to pass all but the first arguments, you can first use shift to "consume" the first argument and then pass "$@" to pass the remaining arguments to another command. In bash (and zsh and ksh, but not in plain POSIX shells like dash), you can do this without messing with the argument list using a variant of array slicing: "${@:3}" will get you the arguments starting with "$3". "${@:3:4}" will get you up to four arguments starting at "$3" (i.e. "$3" "$4" "$5" "$6"), if that many arguments were passed.

Things you probably don't want to do:

"$*" gives all of the arguments stuck together into a single string (separated by spaces, or whatever the first character of $IFS is). This looses the distinction between spaces within arguments and the spaces between arguments, so is generally a bad idea. Although it might be ok for printing the arguments, e.g. echo "$*", provided you don't care about preserving the space within/between distinction.

Assigning the arguments to a regular variable (as in args="$@") mashes all the arguments together just like "$*" does. If you want to store the arguments in a variable, use an array with args=("$@") (the parentheses make it an array), and then reference them as e.g. "${args[0]}" etc (note that bash array indexes start at 0, so $1 will be in args[0], etc).

Leaving off the double-quotes, with either $@ or $*, will try to split each argument up into separate words (based on whitespace or whatever's in $IFS), and also try to expand anything that looks like a filename wildcard into a list of matching filenames. This can have really weird effects, and should almost always be avoided.

SQL count rows in a table

Why don't you just right click on the table and then properties -> Storage and it would tell you the row count. You can use the below for row count in a view

SELECT SUM (row_count) 
FROM sys.dm_db_partition_stats 
WHERE object_id=OBJECT_ID('Transactions')    
AND (index_id=0 or index_id=1)`

How to submit a form on enter when the textarea has focus?

Why do you want a textarea to submit when you hit enter?

A "text" input will submit by default when you press enter. It is a single line input.

<input type="text" value="...">

A "textarea" will not, as it benefits from multi-line capabilities. Submitting on enter takes away some of this benefit.

<textarea name="area"></textarea>

You can add JavaScript code to detect the enter keypress and auto-submit, but you may be better off using a text input.

Handle JSON Decode Error when nothing returned

If you don't mind importing the json module, then the best way to handle it is through json.JSONDecodeError (or json.decoder.JSONDecodeError as they are the same) as using default errors like ValueError could catch also other exceptions not necessarily connected to the json decode one.

from json.decoder import JSONDecodeError


try:
    qByUser = byUsrUrlObj.read()
    qUserData = json.loads(qByUser).decode('utf-8')
    questionSubjs = qUserData["all"]["questions"]
except JSONDecodeError as e:
    # do whatever you want

//EDIT (Oct 2020):

As @Jacob Lee noted in the comment, there could be the basic common TypeError raised when the JSON object is not a str, bytes, or bytearray. Your question is about JSONDecodeError, but still it is worth mentioning here as a note; to handle also this situation, but differentiate between different issues, the following could be used:

from json.decoder import JSONDecodeError


try:
    qByUser = byUsrUrlObj.read()
    qUserData = json.loads(qByUser).decode('utf-8')
    questionSubjs = qUserData["all"]["questions"]
except JSONDecodeError as e:
    # do whatever you want
except TypeError as e:
    # do whatever you want in this case

Search all tables, all columns for a specific value SQL Server

You could query the sys.tables database view to get out the names of the tables, and then use this query to build yourself another query to do the update on the back of that. For instance:

select 'select * from '+name from sys.tables

will give you a script that will run a select * against all the tables in the system catalog, you could alter the string in the select clause to do your update, as long as you know the column name is the same on all the tables you wish to update, so your script would look something like:

select 'update '+name+' set comments = ''(*)''+comments where comments like ''%comment to be updated%'' ' from sys.tables

You could also then predicate on the tables query to only include tables that have a name in a certain format, or are in a subset you want to create the update script for.

How can I remove a key and its value from an associative array?

Use this function to remove specific arrays of keys without modifying the original array:

function array_except($array, $keys) {
  return array_diff_key($array, array_flip((array) $keys));   
} 

First param pass all array, second param set array of keys to remove.

For example:

$array = [
    'color' => 'red', 
    'age' => '130', 
    'fixed' => true
];
$output = array_except($array, ['color', 'fixed']);
// $output now contains ['age' => '130']

Today's Date in Perl in MM/DD/YYYY format

You can do it fast, only using one POSIX function. If you have bunch of tasks with dates, see the module DateTime.

use POSIX qw(strftime);

my $date = strftime "%m/%d/%Y", localtime;
print $date;

HTML Entity Decode

I think that is the exact opposite of the solution chosen.

var decoded = $("<div/>").text(encodedStr).html();

Try it :)

Align the form to the center in Bootstrap 4

You need to use the various Bootstrap 4 centering methods...

  • Use text-center for inline elements.
  • Use justify-content-center for flexbox elements (ie; form-inline)

https://codeply.com/go/Am5LvvjTxC

Also, to offset the column, the col-sm-* must be contained within a .row, and the .row must be in a container...

<section id="cover">
    <div id="cover-caption">
        <div id="container" class="container">
            <div class="row">
                <div class="col-sm-10 offset-sm-1 text-center">
                    <h1 class="display-3">Welcome to Bootstrap 4</h1>
                    <div class="info-form">
                        <form action="" class="form-inline justify-content-center">
                            <div class="form-group">
                                <label class="sr-only">Name</label>
                                <input type="text" class="form-control" placeholder="Jane Doe">
                            </div>
                            <div class="form-group">
                                <label class="sr-only">Email</label>
                                <input type="text" class="form-control" placeholder="[email protected]">
                            </div>
                            <button type="submit" class="btn btn-success ">okay, go!</button>
                        </form>
                    </div>
                    <br>

                    <a href="#nav-main" class="btn btn-secondary-outline btn-sm" role="button">?</a>
                </div>
            </div>
        </div>
    </div>
</section>