Programs & Examples On #Structured programming

How do I use a PriorityQueue?

no different, as declare in javadoc:

public boolean add(E e) {
    return offer(e);
}

How to create a generic array?

Here is the implementation of LinkedList<T>#toArray(T[]):

public <T> T[] toArray(T[] a) {
    if (a.length < size)
        a = (T[])java.lang.reflect.Array.newInstance(
                            a.getClass().getComponentType(), size);
    int i = 0;
    Object[] result = a;
    for (Node<E> x = first; x != null; x = x.next)
        result[i++] = x.item;

    if (a.length > size)
        a[size] = null;

    return a;
}

In short, you could only create generic arrays through Array.newInstance(Class, int) where int is the size of the array.

C# refresh DataGridView when updating or inserted on another form

DataGridView.Refresh and And DataGridView.Update are methods that are inherited from Control. They have to do with redrawing the control which is why new rows don't appear.

My guess is the data retrieval is on the Form_Load. If you want your Button on Form B to retrieve the latest data from the database then that's what you have to do whatever Form_Load is doing.

A nice way to do that is to separate your data retrieval calls into a separate function and call it from both the From Load and Button Click events.

How to read an external properties file in Maven

This answer to a similar question describes how to extend the properties plugin so it can use a remote descriptor for the properties file. The descriptor is basically a jar artifact containing a properties file (the properties file is included under src/main/resources).

The descriptor is added as a dependency to the extended properties plugin so it is on the plugin's classpath. The plugin will search the classpath for the properties file, read the file''s contents into a Properties instance, and apply those properties to the project's configuration so they can be used elsewhere.

Installing Oracle Instant Client

I was able to setup Oracle Instant Client (Basic) 11g2 and Oracle ODBC (32bit) drivers on my 32bit Windows 7 PC. Note: you'll need a 'tnsnames.ora' file because it doesn't come with one. You can Google examples and copy/paste into a text file, change the parameters for your environment.

Setting up Oracle Instant Client-Basic 11g2 (Win7 32-bit)
(I think there's another step or two if your using 64-bit)

Oracle Instant Client

  • Unzip Oracle Instant Client - Basic
  • Put contents in folder like "C:\instantclient"
  • Edit PATH evironment variable, add path to Instant Client folder to the Variable Value.
  • Add new Variable called "TNS_ADMIN" point to same folder as Instant Client.
  • I had to create a "tnsnames.ora" file because it doesn't come with one. Put it in same folder as the client.
  • reboot or use Task Manager to kill "explorer.exe" and restart it to refresh the PATH environment variables.

ODBC Drivers

  • Unzip ODBC drivers
  • Copy all files into same folder as client "C:\instantclient"
  • Use command prompt to run "odbc_install.exe" (should say it was successful)

Note: The "un-documented" things that were hanging me up where...
- All files (Client and Drivers) needed to be in the same folder (nothing in sub-folders).
- Running the ODBC driver from the command prompt will allow you to see if it installs successfully. Double-clicking the installer just flashed a box on the screen, no idea it was failing because no error dialog.

After you've done this you should be able to setup a new DSN Data Source using the Oracle ODBC driver.
-Hope this helps someone else.

Iterating through directories with Python

From python >= 3.5 onward, you can use **, glob.iglob(path/**, recursive=True) and it seems the most pythonic solution, i.e.:

import glob, os

for filename in glob.iglob('/pardadox-music/**', recursive=True):
    if os.path.isfile(filename): # filter dirs
        print(filename)

Output:

/pardadox-music/modules/her1.mod
/pardadox-music/modules/her2.mod
...

Notes:
1 - glob.iglob

glob.iglob(pathname, recursive=False)

Return an iterator which yields the same values as glob() without actually storing them all simultaneously.

2 - If recursive is True, the pattern '**' will match any files and zero or more directories and subdirectories.

3 - If the directory contains files starting with . they won’t be matched by default. For example, consider a directory containing card.gif and .card.gif:

>>> import glob
>>> glob.glob('*.gif') ['card.gif'] 
>>> glob.glob('.c*')['.card.gif']

4 - You can also use rglob(pattern), which is the same as calling glob() with **/ added in front of the given relative pattern.

Open another page in php

<?php
    header("Location: index.html");
?>

Just make sure nothing is actually written to the page prior to this code, or it won't work.

Definitive way to trigger keypress events with jQuery

Of you want to do it in a single line you can use

$("input").trigger(jQuery.Event('keydown', { which: '1'.charCodeAt(0) }));

REST API Best practice: How to accept list of parameter values as input

First:

I think you can do it 2 ways

http://our.api.com/Product/<id> : if you just want one record

http://our.api.com/Product : if you want all records

http://our.api.com/Product/<id1>,<id2> :as James suggested can be an option since what comes after the Product tag is a parameter

Or the one I like most is:

You can use the the Hypermedia as the engine of application state (HATEOAS) property of a RestFul WS and do a call http://our.api.com/Product that should return the equivalent urls of http://our.api.com/Product/<id> and call them after this.

Second

When you have to do queries on the url calls. I would suggest using HATEOAS again.

1) Do a get call to http://our.api.com/term/pumas/productType/clothing/color/black

2) Do a get call to http://our.api.com/term/pumas/productType/clothing,bags/color/black,red

3) (Using HATEOAS) Do a get call to `http://our.api.com/term/pumas/productType/ -> receive the urls all clothing possible urls -> call the ones you want (clothing and bags) -> receive the possible color urls -> call the ones you want

How to upgrade safely php version in wamp server

To add to the above answer (do steps 1-5).

  1. Click on WAMP -> Select PHP -> Versions: Select the new version installed
  2. Check that your PATH folder is updated to new path to PHP so your OS has same PHP version of WAMP.

PostgreSQL next value of the sequences?

If your are not in a session you can just nextval('you_sequence_name') and it's just fine.

what is Ljava.lang.String;@

Ljava.lang.String;@ is returned where you used string arrays as strings. Employee.getSelectCancel() does not seem to return a String[]

Why declare unicode by string in python?

That doesn't set the format of the string; it sets the format of the file. Even with that header, "hello" is a byte string, not a Unicode string. To make it Unicode, you're going to have to use u"hello" everywhere. The header is just a hint of what format to use when reading the .py file.

Launch Bootstrap Modal on page load

In bootstrap 3 you just need to initialise the modal through js and if in the moment of the page load the modal markup is in the page the modal will show up.

In case you want to prevent this, use the option show: false where you initialise the modal. Something like this: $('.modal').modal({ show: false })

How to convert a pandas DataFrame subset of columns AND rows into a numpy array?

Perhaps something like this for the first problem, you can simply access the columns by their names:

>>> df = pd.DataFrame(np.random.rand(4,5), columns = list('abcde'))
>>> df[df['c']>.5][['b','e']]
          b         e
1  0.071146  0.132145
2  0.495152  0.420219

For the second problem:

>>> df[df['c']>.5][['b','e']].values
array([[ 0.07114556,  0.13214495],
       [ 0.49515157,  0.42021946]])

How to compile the finished C# project and then run outside Visual Studio?

If you cannot find the .exe file, rebuild your solution and in your "Output" from Visual Studio the path to the file will be shown.

Build solution path.

Error: Argument is not a function, got undefined

There appear to be many working solutions suggesting the error has many actual causes.

In my case I hadn't declared the controller in app/index.html:

<scipt src="src/controllers/controller-name.controller.js"></script>

Error gone.

append option to select menu?

Something like this:

var option = document.createElement("option");
option.text = "Text";
option.value = "myvalue";
var select = document.getElementById("id-to-my-select-box");
select.appendChild(option);

Use of min and max functions in C++

As Richard Corden pointed, use C++ functions min and max defined in std namespace. They provide type safety, and help to avoid comparing mixed types (i.e. float point vs integer) what sometimes may be undesirable.

If you find that C++ library you use defines min/max as macros as well, it may cause conflicts, then you can prevent unwanted macro substitution calling the min/max functions this way (notice extra brackets):

(std::min)(x, y)
(std::max)(x, y)

Remember, this will effectively disable Argument Dependant Lookup (ADL, also called Koenig lookup), in case you want to rely on ADL.

Firefox and SSL: sec_error_unknown_issuer

I've being going round in circles with Firefox 43, El Capitan and WHM/cPanel SSL installation continually getting the Untrusted site error - I didn't buy the certificate it was handed over to me to install as the last guy walked out the door. Turns out I was installing under the wrong domain because I missed off the www - but the certificate still installed against the domain, when I installed the certificate in WHM using www.domain.com.au it installed now worries and the FF error has gone - the certificate works fine for both www and non-www.

Inheritance with base class constructor with parameters

The problem is that the base class foo has no parameterless constructor. So you must call constructor of the base class with parameters from constructor of the derived class:

public bar(int a, int b) : base(a, b)
{
    c = a * b;
}

Show "loading" animation on button click

If you are using ajax then (making it as simple as possible)

  1. Add your loading gif image to html and make it hidden (using style in html itself now, you can add it to separate CSS):

    <img src="path\to\loading\gif" id="img" style="display:none"/ >
    
  2. Show the image when button is clicked and hide it again on success function

    $('#buttonID').click(function(){
      $('#img').show(); //<----here
      $.ajax({
        ....
       success:function(result){
           $('#img').hide();  //<--- hide again
       }
    }
    

Make sure you hide the image on ajax error callbacks too to make sure the gif hides even if the ajax fails.

How do I make a <div> move up and down when I'm scrolling the page?

Just add position: fixed; in your div style.

I have checked and Its working fine in my code.

jQuery get selected option value (not the text, but the attribute 'value')

$('select').change(function() {
    console.log($(this).val())
});?

jsFiddle example

.val() will get the value.

SQL Server 2008 - Login failed. The login is from an untrusted domain and cannot be used with Windows authentication

In my case, this error was caused by renaming my client machine. I used a new name longer than 13 characters (despite the warning), which resulted in the NETBIOS name being truncated and being different from the full machine name. Once I re-renamed the client to a shorter name, the error went away.

Get Selected value of a Combobox

You can use the below change event to which will trigger when the combobox value will change.

Private Sub ComboBox1_Change()
'your code here
End Sub

Also you can get the selected value using below

ComboBox1.Value

Should IBOutlets be strong or weak under ARC?

While the documentation recommends using weak on properties for subviews, since iOS 6 it seems to be fine to use strong (the default ownership qualifier) instead. That's caused by the change in UIViewController that views are not unloaded anymore.

  • Before iOS 6, if you kept strong links to subviews of the controller's view around, if the view controller's main view got unloaded, those would hold onto the subviews as long as the view controller is around.
  • Since iOS 6, views are not unloaded anymore, but loaded once and then stick around as long as their controller is there. So strong properties won't matter. They also won't create strong reference cycles, since they point down the strong reference graph.

That said, I am torn between using

@property (nonatomic, weak) IBOutlet UIButton *button;

and

@property (nonatomic) IBOutlet UIButton *button;

in iOS 6 and after:

  • Using weak clearly states that the controller doesn't want ownership of the button.

  • But omitting weak doesn't hurt in iOS 6 without view unloading, and is shorter. Some may point out that is also faster, but I have yet to encounter an app that is too slow because of weak IBOutlets.

  • Not using weak may be perceived as an error.

Bottom line: Since iOS 6 we can't get this wrong anymore as long as we don't use view unloading. Time to party. ;)

Retrieve data from website in android app

You can do the HTML parsing but it is not at all recommended instead ask the website owners to provide web services then you can parse that information.

How to pass integer from one Activity to another?

It's simple. On the sender side, use Intent.putExtra:

Intent myIntent = new Intent(A.this, B.class);
myIntent.putExtra("intVariableName", intValue);
startActivity(myIntent);

On the receiver side, use Intent.getIntExtra:

 Intent mIntent = getIntent();
 int intValue = mIntent.getIntExtra("intVariableName", 0);

Why does the program give "illegal start of type" error?

You have a misplaced closing brace before the return statement.

Why is System.Web.Mvc not listed in Add References?

In VS Express 2012 I couldn't find System.Web.Mvc in the "assemblies" tab, but after a bit of searching I found out that I need to look into "assemblies\extensions" tab rather than the default "assemblies\framework" tab.

How can I force clients to refresh JavaScript files?

Cache Busting in ASP.NET Core via a tag helper will handle this for you and allow your browser to keep cached scripts/css until the file changes. Simply add the tag helper asp-append-version="true" to your script (js) or link (css) tag:

<link rel="stylesheet" href="~/css/site.min.css" asp-append-version="true"/>

Dave Paquette has a good example and explanation of cache busting here (bottom of page) Cache Busting

java.sql.SQLException: Exhausted Resultset

You are getting this error because you are using the resultSet before the resultSet.next() method.

To get the count the just use this:

while (rs.next ()) `{ count = rs.getInt (1); }

You will get your result.

How to fix 'sudo: no tty present and no askpass program specified' error?

I was getting this error because I had limited my user to only a single executable 'systemctl' and had misconfigured the visudo file.

Here's what I had:

jenkins ALL=NOPASSWD: systemctl

However, you need to include the full path to the executable, even if it is on your path by default, for example:

jenkins ALL=NOPASSWD: /bin/systemctl

This allows my jenkins user to restart services but not have full root access

Can "git pull --all" update all my local branches?

The script from @larsmans, a bit improved:

#!/bin/sh

set -x
CURRENT=`git rev-parse --abbrev-ref HEAD`
git fetch --all
for branch in "$@"; do
  if ["$branch" -ne "$CURRENT"]; then
    git checkout "$branch" || exit 1
    git rebase "origin/$branch" || exit 1
  fi
done
git checkout "$CURRENT" || exit 1
git rebase "origin/$CURRENT" || exit 1

This, after it finishes, leaves working copy checked out from the same branch as it was before the script was called.

The git pull version:

#!/bin/sh

set -x
CURRENT=`git rev-parse --abbrev-ref HEAD`
git fetch --all
for branch in "$@"; do
  if ["$branch" -ne "$CURRENT"]; then
    git checkout "$branch" || exit 1
    git pull || exit 1
  fi
done
git checkout "$CURRENT" || exit 1
git pull || exit 1

EOL conversion in notepad ++

In Notepad++, use replace all with regular expression. This has advantage over conversion command in menu that you can operate on entire folder w/o having to open each file or drag n drop (on several hundred files it will noticeably become slower) plus you can also set filename wildcard filter.

(\r?\n)|(\r\n?)

to

\n

This will match every possible line ending pattern (single \r, \n or \r\n) back to \n. (Or \r\n if you are converting to windows-style)

To operate on multiple files, either:

  • Use "Replace All in all opened document" in "Replace" tab. You will have to drag and drop all files into Notepad++ first. It's good that you will have control over which file to operate on but can be slow if there several hundreds or thousands files.
  • "Replace in files" in "Find in files" tab, by file filter of you choice, e.g., *.cpp *.cs under one specified directory.

How to install Python package from GitHub?

You need to use the proper git URL:

pip install git+https://github.com/jkbr/httpie.git#egg=httpie

Also see the VCS Support section of the pip documentation.

Don’t forget to include the egg=<projectname> part to explicitly name the project; this way pip can track metadata for it without having to have run the setup.py script.

Downloading folders from aws s3, cp or sync?

In case you need to use another profile, especially cross account. you need to add the profile in the config file

[profile profileName]
region = us-east-1
role_arn = arn:aws:iam::XXX:role/XXXX
source_profile = default

and then if you are accessing only a single file

aws s3 cp s3://crossAccountBucket/dir localdir --profile profileName

Return content with IHttpActionResult for non-OK response

In ASP.NET Web API 2, you can wrap any ResponseMessage in a ResponseMessageResult:

public IHttpActionResult Get()
{
   HttpResponseMessage responseMessage = ...
   return new ResponseMessageResult(responseMessage);
}

In some cases this may be the simplest way to get the desired result, although generally it might be preferable to use the various results in System.Web.Http.Results.

How to replace all special character into a string using C#

Also, It can be done with LINQ

var str = "Hello@Hello&Hello(Hello)";
var characters = str.Select(c => char.IsLetter(c) ? c : ',')).ToArray();             
var output = new string(characters);
Console.WriteLine(output);

How to split a string and assign it to variables

The IPv6 addresses for fields like RemoteAddr from http.Request are formatted as "[::1]:53343"

So net.SplitHostPort works great:

package main

    import (
        "fmt"
        "net"
    )

    func main() {
        host1, port, err := net.SplitHostPort("127.0.0.1:5432")
        fmt.Println(host1, port, err)

        host2, port, err := net.SplitHostPort("[::1]:2345")
        fmt.Println(host2, port, err)

        host3, port, err := net.SplitHostPort("localhost:1234")
        fmt.Println(host3, port, err)
    }

Output is:

127.0.0.1 5432 <nil>
::1 2345 <nil>
localhost 1234 <nil>

Understanding slice notation

The below is the example of an index of a string:

 +---+---+---+---+---+
 | H | e | l | p | A |
 +---+---+---+---+---+
 0   1   2   3   4   5
-5  -4  -3  -2  -1

str="Name string"

Slicing example: [start:end:step]

str[start:end] # Items start through end-1
str[start:]    # Items start through the rest of the array
str[:end]      # Items from the beginning through end-1
str[:]         # A copy of the whole array

Below is the example usage:

print str[0] = N
print str[0:2] = Na
print str[0:7] = Name st
print str[0:7:2] = Nm t
print str[0:-1:2] = Nm ti

Removing specific rows from a dataframe

Here's a solution to your problem using dplyr's filter function.

Although you can pass your data frame as the first argument to any dplyr function, I've used its %>% operator, which pipes your data frame to one or more dplyr functions (just filter in this case).

Once you are somewhat familiar with dplyr, the cheat sheet is very handy.

> print(df <- data.frame(sub=rep(1:3, each=4), day=1:4))
   sub day
1    1   1
2    1   2
3    1   3
4    1   4
5    2   1
6    2   2
7    2   3
8    2   4
9    3   1
10   3   2
11   3   3
12   3   4
> print(df <- df %>% filter(!((sub==1 & day==2) | (sub==3 & day==4))))
   sub day
1    1   1
2    1   3
3    1   4
4    2   1
5    2   2
6    2   3
7    2   4
8    3   1
9    3   2
10   3   3

Page redirect with successful Ajax request

Just do some error checking, and if everything passes then set window.location to redirect the user to a different page.

$.ajax({
    url: 'mail3.php',
    type: 'POST',
    data: 'contactName=' + name + '&contactEmail=' + email + '&spam=' + spam,

    success: function(result) {
        //console.log(result);
        $('#results,#errors').remove();
        $('#contactWrapper').append('<p id="results">' + result + '</p>');
        $('#loading').fadeOut(500, function() {
            $(this).remove();

        });

        if ( /*no errors*/ ) {
            window.location='thank-you.html'
        }

    }
});

How to get the stream key for twitch.tv

You will get it here (change "yourtwitch" by your twitch nickname")

http://www.twitch.tv/yourtwitch/dashboard/streamkey

The link simply moved. You can get this link on the main page of twitch.tv, click on your name then "Dashboard".

How to install Google Play Services in a Genymotion VM (with no drag and drop support)?

3 steps to download the Google Play services Using Genymotion emulator

1. click the right bottom arrow in the toolbar enter image description here

2. Downloading Bar

enter image description here

3. Needs to restart

enter image description here

How to get difference between two rows for a column field?

I'd just make a little function for that. Toss in the two values you need to know the difference between and have it subtract the smaller from the larger value. Something like:

CREATE FUNCTION [dbo].[NumDifference] 
    (   @p1 FLOAT,
        @p2 FLOAT )
RETURNS FLOAT
AS
BEGIN
    DECLARE @Diff FLOAT
    IF @p1 > @p2 SET @Diff = @p1 - @p2 ELSE SET @Diff = @p2 - @p1
    RETURN @Diff
END

In a query to get the difference between column a and b:

SELECT a, b, dbo.NumDifference(a, b) FROM YourTable

What does <> mean in excel?

It means "not equal to" (as in, the values in cells E37-N37 are not equal to "", or in other words, they are not empty.)

What are native methods in Java and where should they be used?

Native methods allow you to use code from other languages such as C or C++ in your java code. You use them when java doesn't provide the functionality that you need. For example, if I were writing a program to calculate some equation and create a line graph of it, I would use java, because it is the language I am best in. However, I am also proficient in C. Say in part of my program I need to calculate a really complex equation. I would use a native method for this, because I know some C++ and I know that C++ is much faster than java, so if I wrote my method in C++ it would be quicker. Also, say I want to interact with another program or device. This would also use a native method, because C++ has something called pointers, which would let me do that.

How to center a table of the screen (vertically and horizontally)

Horizontal centering is easy. You just need to set both margins to "auto":

table {
  margin-left: auto;
  margin-right: auto;
}

Vertical centering usually is achieved by setting the parent element display type to table-cell and using vertical-align property. Assuming you have a <div class="wrapper"> around your table:

.wrapper {
  display: table-cell;
  vertical-align: middle;
}

More detailed information may be found on http://www.w3.org/Style/Examples/007/center

If you need support for older versions of Internet Explorer (I do not know what works in what version of this strange and rarely used browser ;-) ) then you may want to search the web for more information, like: http://www.jakpsatweb.cz/css/css-vertical-center-solution.html (just a first hit, which seems to mention IE)

How can I measure the similarity between two images?

to expand on Vaibhav's note, hugin is an open-source 'autostitcher' which should have some insight on the problem.

AngularJS: factory $http.get JSON file

this answer helped me out a lot and pointed me in the right direction but what worked for me, and hopefully others, is:

menuApp.controller("dynamicMenuController", function($scope, $http) {
$scope.appetizers= [];
$http.get('config/menu.json').success(function(data) { 
    console.log("success!");
    $scope.appetizers = data.appetizers;
        console.log(data.appetizers);
    });    
});

Global Variable from a different file Python

Just put your globals in the file you are importing.

Should I learn C before learning C++?

There is no need to learn C before learning C++.

They are different languages. It is a common misconception that C++ is in some way dependent on C and not a fully specified language on its own.

Just because C++ shares a lot of the same syntax and a lot of the same semantics, does not mean you need to learn C first.

If you learn C++ you will eventually learn most of C with some differences between the languages that you will learn over time. In fact its a very hard thing to write proper C++ because intermediate C++ programmers tend to write C/C++.That is true whether or not you started with C or started with C++.

If you know C first, then that is good plus to learning C++. You will start with knowing a chunk of the language. If you do not know C first then there is no point focusing on a different language. There are plenty of good books and tutorials available that start you from knowing nothing and will cover anything you would learn from C which applies to C++ as well.

Please see further reasoning in this answer.

What is the best way to generate a unique and short file name in Java

Problem is synchronization. Separate out regions of conflict.

Name the file as : (server-name)_(thread/process-name)_(millisecond/timestamp).(extension)
example : aws1_t1_1447402821007.png

How to create nonexistent subdirectories recursively using Bash?

mkdir -p newDir/subdir{1..8}
ls newDir/
subdir1 subdir2 subdir3 subdir4 subdir5 subdir6 subdir7 subdir8

Recyclerview and handling different type of row inflation

According to Gil great answer I solved by Overriding the getItemViewType as explained by Gil. His answer is great and have to be marked as correct. In any case, I add the code to reach the score:

In your recycler adapter:

@Override
public int getItemViewType(int position) {
    int viewType = 0;
    // add here your booleans or switch() to set viewType at your needed
    // I.E if (position == 0) viewType = 1; etc. etc.
    return viewType;
}

@Override
public FileViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    if (viewType == 0) {
        return new MyViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.my_layout_for_first_row, parent, false));
    }

    return new MyViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.my_other_rows, parent, false));
}

By doing this, you can set whatever custom layout for whatever row!

Anaconda-Navigator - Ubuntu16.04

To run anaconda-navigator:

$ source ~/anaconda3/bin/activate root
$ anaconda-navigator

Is it possible to sort a ES6 map object?

The idea is to extract the keys of your map into an array. Sort this array. Then iterate over this sorted array, get its value pair from the unsorted map and put them into a new map. The new map will be in sorted order. The code below is it's implementation:

var unsortedMap = new Map();
unsortedMap.set('2-1', 'foo');
unsortedMap.set('0-1', 'bar');

// Initialize your keys array
var keys = [];
// Initialize your sorted maps object
var sortedMap = new Map();

// Put keys in Array
unsortedMap.forEach(function callback(value, key, map) {
    keys.push(key);
});

// Sort keys array and go through them to put in and put them in sorted map
keys.sort().map(function(key) {
    sortedMap.set(key, unsortedMap.get(key));
});

// View your sorted map
console.log(sortedMap);

'Best' practice for restful POST response

Returning the whole object on an update would not seem very relevant, but I can hardly see why returning the whole object when it is created would be a bad practice in a normal use case. This would be useful at least to get the ID easily and to get the timestamps when relevant. This is actually the default behavior got when scaffolding with Rails.

I really do not see any advantage to returning only the ID and doing a GET request after, to get the data you could have got with your initial POST.

Anyway as long as your API is consistent I think that you should choose the pattern that fits your needs the best. There is not any correct way of how to build a REST API, imo.

How do I decode a base64 encoded string?

Simple:

byte[] data = Convert.FromBase64String(encodedString);
string decodedString = Encoding.UTF8.GetString(data);

Difference between "while" loop and "do while" loop

while test the condition before executing statements in the while loop.

do while test the condition after having executed statement inside the loop.

How can I make an image transparent on Android?

Use:

ImageView image = (ImageView) findViewById(R.id.image);
image.setAlpha(150); // Value: [0-255]. Where 0 is fully transparent
                     // and 255 is fully opaque. Set the value according
                     // to your choice, and you can also use seekbar to
                     // maintain the transparency.

How to check if JavaScript object is JSON

The answer by @PeterWilkinson didn't work for me because a constructor for a "typed" object is customized to the name of that object. I had to work with typeof

function isJson(obj) {
    var t = typeof obj;
    return ['boolean', 'number', 'string', 'symbol', 'function'].indexOf(t) == -1;
}

How can I close a login form and show the main form without my application closing?

The reason your main form isn't showing is because once you close the login form, your application's message pump is shut down, which causes the entire application to exit. The Windows message loop is tied to the login form because that's the one you have set as the startup form in your project properties. Look in your "Program.cs" file, and you'll see the responsible bit of code: Application.Run(new LoginForm()). Check out the documentation for that method here on MSDN, which explains this in greater detail.

The best solution is to move the code out of your login form into the "Program.cs" file. When your program first starts, you'll create and show the login form as a modal dialog (which runs on a separate message loop and blocks execution of the rest of your code until it closes). When the login dialog closes, you'll check its DialogResult property to see if the login was successful. If it was, you can start the main form using Application.Run (thus creating the main message loop); otherwise, you can exit the application without showing any form at all. Something like this:

static void Main()
{
    LoginForm fLogin = new LoginForm();
    if (fLogin.ShowDialog() == DialogResult.OK)
    {
        Application.Run(new MainForm());
    }
    else
    {
        Application.Exit();
    }
}

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

If you would like to 'add' additional items to a page, you may want to create an array of maps. This is how I created an array of maps and then added results to it:

import { Product } from '../models/product';

products: Array<Product>;          // Initialize the array.

[...]

let i = 0;
this.service.products( i , (result) => {

    if ( i == 0 ) {
        // Create the first element of the array.
        this.products = Array(result);
    } else { 
        // Add to the array of maps.
        this.products.push(result);
    }

});

Where product.ts look like...

export class Product {
    id: number;
    [...]
}

What is the meaning of "POSIX"?

Let me give the churlish "unofficial" explanation.

POSIX is a set of standards which attempts to distinguish "UNIX" and UNIX-like systems from those which are incompatible with them. It was created by the U.S. government for procurement purposes. The idea was that the U.S. federal procurements needed a way to legally specify the requirements for various sorts of bids and contracts in a way that could be used to exclude systems to which a given existing code base or programming staff would NOT be portable.

Since POSIX was written post facto ... to describe a loosely similar set of competing systems ... it was NOT written in a way that could be implemented.

So, for example, Microsoft's NT was written with enough POSIX conformance to qualify for some bids ... even though the POSIX subsystem was essentially useless in terms of practical portability and compatibility with UNIX systems.

Various other standards for UNIX have been written over the decades. Things like the SPEC1170 (specified eleven hundred and seventy function calls which had to be implemented compatibly) and various incarnations of the SUS (Single UNIX Specification).

For the most part these "standards" have been inadequate to any practical technical application. They most exist for argumentation, legal wrangling and other dysfunctional reasons.

Android: how to parse URL String with spaces to URI object?

To handle spaces, @, and other unsafe characters in arbitrary locations in the url path, Use Uri.Builder in combination with a local instance of URL as I have described here:

private Uri.Builder builder;
public Uri getUriFromUrl(String thisUrl) {
    URL url = new URL(thisUrl);
    builder =  new Uri.Builder()
                            .scheme(url.getProtocol())
                            .authority(url.getAuthority())
                            .appendPath(url.getPath());
    return builder.build();
}

Access denied for root user in MySQL command-line

Are you logging into MySQL as root? You have to explicitly grant privileges to your "regular" MySQL user account while logged in as MySQL root.

First set up a root account for your MySQL database.

In the terminal type:

mysqladmin -u root password 'password'

To log into MySQL, use this:

mysql -u root -p

To set the privileges manually start the server with the skip-grant-tables option, open mysql client and manually update the mysql.user table and/or the mysql.db tables. This can be a tedious task though so if what you need is an account with all privs I would do the following.

Start the server with the skip-grant-tables option

Start mysql client (without a username/password)

Issue the command

flush privileges;

which forces the grant tables to be loaded.

Create a new account with the GRANT command something like this (but replacing username and password with whatever you want to use.

GRANT ALL on *.* to 'username'@'localhost' identified by 'password';

Restart the server in normal mode (without skip-grant-tables) and log in with your newly created account.

Refer this MySQL docs.

Go to "next" iteration in JavaScript forEach loop

JavaScript's forEach works a bit different from how one might be used to from other languages for each loops. If reading on the MDN, it says that a function is executed for each of the elements in the array, in ascending order. To continue to the next element, that is, run the next function, you can simply return the current function without having it do any computation.

Adding a return and it will go to the next run of the loop:

_x000D_
_x000D_
var myArr = [1,2,3,4];_x000D_
_x000D_
myArr.forEach(function(elem){_x000D_
  if (elem === 3) {_x000D_
    return;_x000D_
  }_x000D_
_x000D_
  console.log(elem);_x000D_
});
_x000D_
_x000D_
_x000D_

Output: 1, 2, 4

Using WGET to run a cronjob PHP

If you want get output only when php fail:

php -r 'echo file_get_contents(http://www.example.com/cronit.php);'

This way you receive an email from cronjob only when the script fails and not whenever the php is called.

Where is the syntax for TypeScript comments documented?

You can add information about parameters, returns, etc. as well using:

/**
* This is the foo function
* @param bar This is the bar parameter
* @returns returns a string version of bar
*/
function foo(bar: number): string {
    return bar.toString()
}

This will cause editors like VS Code to display it as the following:

enter image description here

How do I generate random numbers in Dart?

For me the easiest way is to do:

import 'dart:math';
Random rnd = new Random();
r = min + rnd.nextInt(max - min);
//where min and max should be specified.

Thanks to @adam-singer explanation in here.

How to run mvim (MacVim) from Terminal?

If you already have macVim installed: /Applications/MacVim.app/Contents/MacOS/Vim -g will give you macVim GUI.

just add an alias.

i use gvim because that is what i use on linux for gnome-vim.

alias gvim='/Applications/MacVim.app/Contents/MacOS/Vim -g'

How to output an Excel *.xls file from classic ASP

You must specify the file to be downloaded (attachment) by the client in the http header:

Response.ContentType = "application/vnd.ms-excel"
Response.AppendHeader "content-disposition", "attachment: filename=excelTest.xls"

http://classicasp.aspfaq.com/general/how-do-i-prompt-a-save-as-dialog-for-an-accepted-mime-type.html

How do you do Impersonation in .NET?

I'm aware that I'm quite late for the party, but I consider that the library from Phillip Allan-Harding, it's the best one for this case and similar ones.

You only need a small piece of code like this one:

private const string LOGIN = "mamy";
private const string DOMAIN = "mongo";
private const string PASSWORD = "HelloMongo2017";

private void DBConnection()
{
    using (Impersonator user = new Impersonator(LOGIN, DOMAIN, PASSWORD, LogonType.LOGON32_LOGON_NEW_CREDENTIALS, LogonProvider.LOGON32_PROVIDER_WINNT50))
    {
    }
}

And add his class:

.NET (C#) Impersonation with Network Credentials

My example can be used if you require the impersonated logon to have network credentials, but it has more options.

matplotlib colorbar for scatter

From the matplotlib docs on scatter 1:

cmap is only used if c is an array of floats

So colorlist needs to be a list of floats rather than a list of tuples as you have it now. plt.colorbar() wants a mappable object, like the CircleCollection that plt.scatter() returns. vmin and vmax can then control the limits of your colorbar. Things outside vmin/vmax get the colors of the endpoints.

How does this work for you?

import matplotlib.pyplot as plt
cm = plt.cm.get_cmap('RdYlBu')
xy = range(20)
z = xy
sc = plt.scatter(xy, xy, c=z, vmin=0, vmax=20, s=35, cmap=cm)
plt.colorbar(sc)
plt.show()

Image Example

Overlay with spinner

Here is an Pure CSS endless spinner. Position absolute, to place the buttons on top of each other.

_x000D_
_x000D_
button {
            position: absolute;
            width: 150px;
            font-size: 120%;
            padding: 5px;
            background: #B52519;
            color: #EAEAEA;
            border: none;
            margin: 50px;
            border-radius: 5px;
            display: flex;
            align-content: center;
            justify-content: center;
            transition: all 0.5s;
            cursor: pointer;
        }

        #orderButton:hover {
            color: #c8c8c8;
        }

        #orderLoading {
            animation: rotation 1s infinite linear;
            height: 20px;
            width: 20px;
            display: flex;
            justify-content: center;
            align-items: center;
            border-radius: 100%;
            border: 2px solid;
            border-style: outset;
            color: #fff;
        }

        @keyframes rotation {
            from {
                transform: rotate(0deg);
            }
            to {
                transform: rotate(360deg);
            }
        }
_x000D_
<button><div id="orderLoading"></div></button>
<button id="orderButton" onclick="this.style.visibility= 'hidden';">Order!</button>
_x000D_
_x000D_
_x000D_

Change color inside strings.xml

I would use a SpannableString to change the color.

int colorBlue = getResources().getColor(R.color.blue);
    String text = getString(R.string.text);
    SpannableString spannable = new SpannableString(text);
    // here we set the color
    spannable.setSpan(new ForegroundColorSpan(colorBlue), 0, text.length(), 0);

OR you may try this

How do I get the current time only in JavaScript

Try

new Date().toLocaleTimeString().replace("/.*(\d{2}:\d{2}:\d{2}).*/", "$1");

Or

new Date().toTimeString().split(" ")[0];

Apply CSS styles to an element depending on its child elements

Basically, no. The following would be what you were after in theory:

div.a < div { border: solid 3px red; }

Unfortunately it doesn't exist.

There are a few write-ups along the lines of "why the hell not". A well fleshed out one by Shaun Inman is pretty good:

http://www.shauninman.com/archive/2008/05/05/css_qualified_selectors

@selector() in Swift?

For future readers, I found that I experienced a problem and was getting an unrecognised selector sent to instance error that was caused by marking the target func as private.

The func MUST be publicly visible to be called by an object with a reference to a selector.

How to use LINQ to select object with minimum or maximum property value

Unfortunately there isn't a built-in method to do this, but it's easy enough to implement for yourself. Here are the guts of it:

public static TSource MinBy<TSource, TKey>(this IEnumerable<TSource> source,
    Func<TSource, TKey> selector)
{
    return source.MinBy(selector, null);
}

public static TSource MinBy<TSource, TKey>(this IEnumerable<TSource> source,
    Func<TSource, TKey> selector, IComparer<TKey> comparer)
{
    if (source == null) throw new ArgumentNullException("source");
    if (selector == null) throw new ArgumentNullException("selector");
    comparer ??= Comparer<TKey>.Default;

    using (var sourceIterator = source.GetEnumerator())
    {
        if (!sourceIterator.MoveNext())
        {
            throw new InvalidOperationException("Sequence contains no elements");
        }
        var min = sourceIterator.Current;
        var minKey = selector(min);
        while (sourceIterator.MoveNext())
        {
            var candidate = sourceIterator.Current;
            var candidateProjected = selector(candidate);
            if (comparer.Compare(candidateProjected, minKey) < 0)
            {
                min = candidate;
                minKey = candidateProjected;
            }
        }
        return min;
    }
}

Example usage:

var firstBorn = People.MinBy(p => p.DateOfBirth ?? DateTime.MaxValue);

Note that this will throw an exception if the sequence is empty, and will return the first element with the minimal value if there's more than one.

Alternatively, you can use the implementation we've got in MoreLINQ, in MinBy.cs. (There's a corresponding MaxBy, of course.)

Install via package manager console:

PM> Install-Package morelinq

Apache VirtualHost 403 Forbidden

This works on Linux Fedora for VirtualHost : ( Lampp/Xampp )

Go to : /opt/lampp/etc/extra

Open : httpd-vhosts.conf

Insert this in httpd-vhosts.conf

<VirtualHost *:80>
ServerAdmin [email protected]
DocumentRoot "/opt/lampp/APPS/My_App"
ServerName votemo.test
ServerAlias www.votemo.test
ErrorLog "logs/votemo.test-error_log"
CustomLog "logs/votemo.test-access_log" common
<Directory "/opt/lampp/APPS/My_App">
    Options FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>

p.s. : Don't forget to comment the previous exemple already present in httpd-vhosts.conf

Set your hosts system file :

Go to : /etc/ folder find hosts file ( /etc/hosts )

I insert this : (but not sure to 100% if this good)

127.0.0.1       votemo.test

::1         votemo.test

-> Open or Restart Apache.

Open a console and paste this command for open a XAMPP graphic interface :

sudo /opt/lampp/manager-linux-x64.run

Note : Adjust path how you want to your app folder

ex: DocumentRoot "/home/USER/Desktop/My_Project"

and set directory path too :

ex : ... <Directory "/home/USER/Desktop/My_Project"> ...

But this should be tested, comment if this work ...

Additionnal notes :

  • Localisation Lampp folder : (Path) /opt/lampp

  • Start Lampp : sudo /opt/lampp/lampp start

  • Adjust rights if needed : sudo chmod o+w /opt/lampp/manager-linux-x64.run

  • Path to hosts file : /etc/hosts

popup form using html/javascript/css

But the problem with this code is that, I cannot change the content popup content from "Please enter your name" to my html form.

Umm. Just change the string passed to the prompt() function.

While searching, I found that there we CANNOT change the content of popup Prompt Box

You can't change the title. You can change the content, it is the first argument passed to the prompt() function.

JWT (Json Web Token) Audience "aud" versus Client_Id - What's the difference?

If you came here searching OpenID Connect (OIDC): OAuth 2.0 != OIDC

I recognize that this is tagged for oauth 2.0 and NOT OIDC, however there is frequently a conflation between the 2 standards since both standards can use JWTs and the aud claim. And one (OIDC) is basically an extension of the other (OAUTH 2.0). (I stumbled across this question looking for OIDC myself.)

OAuth 2.0 Access Tokens##

For OAuth 2.0 Access tokens, existing answers pretty well cover it. Additionally here is one relevant section from OAuth 2.0 Framework (RFC 6749)

For public clients using implicit flows, this specification does not provide any method for the client to determine what client an access token was issued to.
...
Authenticating resource owners to clients is out of scope for this specification. Any specification that uses the authorization process as a form of delegated end-user authentication to the client (e.g., third-party sign-in service) MUST NOT use the implicit flow without additional security mechanisms that would enable the client to determine if the access token was issued for its use (e.g., audience- restricting the access token).

OIDC ID Tokens##

OIDC has ID Tokens in addition to Access tokens. The OIDC spec is explicit on the use of the aud claim in ID Tokens. (openid-connect-core-1.0)

aud
REQUIRED. Audience(s) that this ID Token is intended for. It MUST contain the OAuth 2.0 client_id of the Relying Party as an audience value. It MAY also contain identifiers for other audiences. In the general case, the aud value is an array of case sensitive strings. In the common special case when there is one audience, the aud value MAY be a single case sensitive string.

furthermore OIDC specifies the azp claim that is used in conjunction with aud when aud has more than one value.

azp
OPTIONAL. Authorized party - the party to which the ID Token was issued. If present, it MUST contain the OAuth 2.0 Client ID of this party. This Claim is only needed when the ID Token has a single audience value and that audience is different than the authorized party. It MAY be included even when the authorized party is the same as the sole audience. The azp value is a case sensitive string containing a StringOrURI value.

Integer to IP Address - C

From string to int and back

const char * s_ip = "192.168.0.5";
unsigned int ip;
unsigned char * c_ip = (unsigned char *)&ip;
sscanf(s_ip, "%hhu.%hhu.%hhu.%hhu", &c_ip[3], &c_ip[2], &c_ip[1], &c_ip[0]);
printf("%u.%u.%u.%u", ((ip & 0xff000000) >> 24), ((ip & 0x00ff0000) >> 16), ((ip & 0x0000ff00) >> 8), (ip & 0x000000ff));

%hhu instructs sscanf to read into unsigned char pointer; (Reading small int with scanf)


inet_ntoa from glibc

char *
inet_ntoa (struct in_addr in)
{
unsigned char *bytes = (unsigned char *) &in;
__snprintf (buffer, sizeof (buffer), "%d.%d.%d.%d",
bytes[0], bytes[1], bytes[2], bytes[3]);
return buffer;
}

Does JavaScript have the interface type (such as Java's 'interface')?

When you want to use a transcompiler, then you could give TypeScript a try. It supports draft ECMA features (in the proposal, interfaces are called "protocols") similar to what languages like coffeescript or babel do.

In TypeScript your interface can look like:

interface IMyInterface {
    id: number; // TypeScript types are lowercase
    name: string;
    callback: (key: string; value: any; array: string[]) => void;
    type: "test" | "notATest"; // so called "union type"
}

What you can't do:

SQL join on multiple columns in same tables

Join like this:

ON a.userid = b.sourceid AND a.listid = b.destinationid;

Python class input argument

Remove the name param from the class declaration. The init method is used to pass arguments to a class at creation.

class Person(object):
  def __init__(self, name):
    self.name = name

me = Person("TheLazyScripter")
print me.name

Android camera intent

It took me some hours to get this working. The code it's almost a copy-paste from developer.android.com, with a minor difference.

Request this permission on the AndroidManifest.xml:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

On your Activity, start by defining this:

static final int REQUEST_IMAGE_CAPTURE = 1;
private Bitmap mImageBitmap;
private String mCurrentPhotoPath;
private ImageView mImageView;

Then fire this Intent in an onClick:

Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (cameraIntent.resolveActivity(getPackageManager()) != null) {
    // Create the File where the photo should go
    File photoFile = null;
    try {
        photoFile = createImageFile();
    } catch (IOException ex) {
        // Error occurred while creating the File
        Log.i(TAG, "IOException");
    }
    // Continue only if the File was successfully created
    if (photoFile != null) {
        cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
        startActivityForResult(cameraIntent, REQUEST_IMAGE_CAPTURE);
    }
}

Add the following support method:

private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES);
    File image = File.createTempFile(
            imageFileName,  // prefix
            ".jpg",         // suffix
            storageDir      // directory
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = "file:" + image.getAbsolutePath();
    return image;
}

Then receive the result:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
        try {
            mImageBitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), Uri.parse(mCurrentPhotoPath));
            mImageView.setImageBitmap(mImageBitmap);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

What made it work is the MediaStore.Images.Media.getBitmap(this.getContentResolver(), Uri.parse(mCurrentPhotoPath)), which is different from the code from developer.android.com. The original code gave me a FileNotFoundException.

Read .doc file with python

I was trying to to the same, I found lots of information on reading .docx but much less on .doc; Anyway, I managed to read the text using the following:

import win32com.client

word = win32com.client.Dispatch("Word.Application")
word.visible = False
wb = word.Documents.Open("myfile.doc")
doc = word.ActiveDocument
print(doc.Range().Text)

How to read strings from a Scanner in a Java console application?

Scanner scanner = new Scanner(System.in);
int employeeId, supervisorId;
String name;
System.out.println("Enter employee ID:");
employeeId = scanner.nextInt();
scanner.nextLine(); //This is needed to pick up the new line
System.out.println("Enter employee name:");
name = scanner.nextLine();
System.out.println("Enter supervisor ID:");
supervisorId = scanner.nextInt();

Calling nextInt() was a problem as it didn't pick up the new line (when you hit enter). So, calling scanner.nextLine() after that does the work.

Java enum - why use toString instead of name

name() is a "built-in" method of enum. It is final and you cannot change its implementation. It returns the name of enum constant as it is written, e.g. in upper case, without spaces etc.

Compare MOBILE_PHONE_NUMBER and Mobile phone number. Which version is more readable? I believe the second one. This is the difference: name() always returns MOBILE_PHONE_NUMBER, toString() may be overriden to return Mobile phone number.

unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard

You can register a class for your UITableViewCell like this:

With Swift 3+:

self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")

With Swift 2.2:

self.tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")

Make sure same identifier "cell" is also copied at your storyboard's UITableViewCell.

"self" is for getting the class use the class name followed by .self.

jQuery UI Dialog - missing close icon

I know this question is old but I just had this issue with jquery-ui v1.12.0.

Short Answer Make sure you have a folder called Images in the same place you have jquery-ui.min.css. The images folder must contains the images found with a fresh download of the jquery-ui

Long answer

My issue is that I am using gulp to merge all of my css files into a single file. When I do that, I am changing the location of the jquery-ui.min.css. The css code for the dialog expects a folder called Images in the same directory and inside this folder it expects default icons. since gulp was not copying the images into the new destination it was not showing the x icon.

Best way to get identity of inserted row?

@@IDENTITY is the last identity inserted using the current SQL Connection. This is a good value to return from an insert stored procedure, where you just need the identity inserted for your new record, and don't care if more rows were added afterward.

SCOPE_IDENTITY is the last identity inserted using the current SQL Connection, and in the current scope -- that is, if there was a second IDENTITY inserted based on a trigger after your insert, it would not be reflected in SCOPE_IDENTITY, only the insert you performed. Frankly, I have never had a reason to use this.

IDENT_CURRENT(tablename) is the last identity inserted regardless of connection or scope. You could use this if you want to get the current IDENTITY value for a table that you have not inserted a record into.

Integrating the ZXing library directly into my Android application

Have you seen the wiki pages on the zxing website? It seems you might find GettingStarted, DeveloperNotes and ScanningViaIntent helpful.

Lining up labels with radio buttons in bootstrap

In Bootstrap 4 you can use the form-check-inline class.

<div class="form-check form-check-inline">
  <input class="form-check-input" type="radio" name="queryFieldName" id="option1" value="1">
  <label class="form-check-label" for="option1">First</label>
</div>
<div class="form-check form-check-inline">
  <input class="form-check-input" type="radio" name="queryFieldName" id="option2" value="2">
  <label class="form-check-label" for="option2">Second</label>
</div>

How to convert int to Integer

i it integer, int to Integer

Integer intObj = new Integer(i);

add to collection

list.add(String.valueOf(intObj));

send mail to multiple receiver with HTML mailto

"There are no safe means of assigning multiple recipients to a single mailto: link via HTML. There are safe, non-HTML, ways of assigning multiple recipients from a mailto: link."

http://www.sightspecific.com/~mosh/www_faq/multrec.html

For a quick fix to your problem, change your ; to a comma , and eliminate the spaces between email addresses

<a href='mailto:[email protected],[email protected]'>Email Us</a>

How to convert array into comma separated string in javascript

The method array.toString() actually calls array.join() which result in a string concatenated by commas. ref

_x000D_
_x000D_
var array = ['a','b','c','d','e','f'];_x000D_
document.write(array.toString()); // "a,b,c,d,e,f"
_x000D_
_x000D_
_x000D_

Also, you can implicitly call Array.toString() by making javascript coerce the Array to an string, like:

//will implicitly call array.toString()
str = ""+array;
str = `${array}`;

Array.prototype.join()

The join() method joins all elements of an array into a string.

Arguments:

It accepts a separator as argument, but the default is already a comma ,

str = arr.join([separator = ','])

Examples:

var array = ['A', 'B', 'C'];
var myVar1 = array.join();      // 'A,B,C'
var myVar2 = array.join(', ');  // 'A, B, C'
var myVar3 = array.join(' + '); // 'A + B + C'
var myVar4 = array.join('');    // 'ABC'

Note:

If any element of the array is undefined or null , it is treated as an empty string.

Browser support:

It is available pretty much everywhere today, since IE 5.5 (1999~2000).

References

Auto generate function documentation in Visual Studio

You can use code snippets to insert any lines you want.

Also, if you type three single quotation marks (''') on the line above the function header, it will insert the XML header template that you can then fill out.

These XML comments can be interpreted by documentation software, and they are included in the build output as an assembly.xml file. If you keep that XML file with the DLL and reference that DLL in another project, those comments become available in intellisense.

Detect backspace and del on "input" event?

Use .onkeydown and cancel the removing with return false;. Like this:

var input = document.getElementById('myInput');

input.onkeydown = function() {
    var key = event.keyCode || event.charCode;

    if( key == 8 || key == 46 )
        return false;
};

Or with jQuery, because you added a jQuery tag to your question:

jQuery(function($) {
  var input = $('#myInput');
  input.on('keydown', function() {
    var key = event.keyCode || event.charCode;

    if( key == 8 || key == 46 )
        return false;
  });
});

?

React Error: Target Container is not a DOM Element

Just to give an alternative solution, because it isn't mentioned.

It's perfectly fine to use the HTML attribute defer here. So when loading the DOM, a regular <script> will load when the DOM hits the script. But if we use defer, then the DOM and the script will load in parallel. The cool thing is the script gets evaluated in the end - when the DOM has loaded (source).

<script src="{% static "build/react.js" %}" defer></script>

Link a photo with the cell in excel

Select both the column you are sorting, and the column that the picture is in (I am assuming the picture is small compared to the cell, i.e. it is "in" the cell). Make sure that the object positioning property is set as "move but don't size with cells". Now if you do a sort, the pictures will move with the list being sorted.

Note - you must include the column with the picture in your range when you sort, and the picture must fit inside the cell.

The following VBA snippet will make sure all pictures in your spreadsheet have their "move and size" property set:

Sub moveAndSize()
Dim s As Shape
For Each s In ActiveSheet.Shapes
  If s.Type = msoPicture Or s.Type = msoLinkedPicture Or s.Type = msoPlaceholder Then
    s.Placement = xlMove
  End If
Next
End Sub

If you want to make sure the picture continues to fit after you move it, you can use xlMoveAndSize instead of xlMove.

TypeScript typed array usage

You could try either of these. They are not giving me errors.

It is also the suggested method from typescript for array declaration.

By using the Array<Thing> it is making use of the generics in typescript. It is similar to asking for a List<T> in c# code.

// Declare with default value
private _possessions: Array<Thing> = new Array<Thing>();
// or
private _possessions: Array<Thing> = [];
// or -> prefered by ts-lint
private _possessions: Thing[] = [];

or

// declare
private _possessions: Array<Thing>;
// or -> preferd by ts-lint
private _possessions: Thing[];

constructor(){
    //assign
    this._possessions = new Array<Thing>();
    //or
    this._possessions = [];
}

Get the correct week number of a given date

The easiest way to determine the week number ISO 8601 style using c# and the DateTime class.

Ask this: the how-many-eth thursday of the year is the thursday of this week. The answer equals the wanted week number.

var dayOfWeek = (int)moment.DayOfWeek;
// Make monday the first day of the week
if (--dayOfWeek < 0)
    dayOfWeek = 6;
// The whole nr of weeks before this thursday plus one is the week number
var weekNumber = (moment.AddDays(3 - dayOfWeek).DayOfYear - 1) / 7 + 1;

Disabling Chrome Autofill

It is so simple and tricky :)

google chrome basically search for every first visible password element inside the <form>, <body> and <iframe> tags to enable auto refill for them, so to disable this you need to add a dummy password element as the following:

    • if your password element inside a <form> tag you need to put the dummy element as the first element in your form immediately after <form> open tag

    • if your password element not inside a <form> tag put the dummy element as the first element in your html page immediately after <body> open tag

  1. You need to hide the dummy element without using css display:none so basically use the following as a dummy password element.

    <input type="password" style="width: 0;height: 0; visibility: hidden;position:absolute;left:0;top:0;"/>
    

Clear the cache in JavaScript

If you are using php can do:

 <script src="js/myscript.js?rev=<?php echo time();?>"
    type="text/javascript"></script>

Pass array to mvc Action via AJAX

Set the traditional property to true before making the get call. i.e.:

jQuery.ajaxSettings.traditional = true

$.get('/controller/MyAction', { vals: arrayOfValues }, function (data) {... 

Bootstrap 3 collapsed menu doesn't close on click

you may want to just ensure you're loading your jQuery and Bootstrap.min.js ATF. Your navigation is the first thing to render on the page, so if you have your scripts in the bottom of your HTML, you're losing any JavaScript functionality.

Statically rotate font-awesome icons

New Font-Awesome v5 has Power Transforms

You can rotate any icon by adding attribute data-fa-transform to icon

<i class="fas fa-magic" data-fa-transform="rotate-45"></i>

Here is a fiddle

For more information, check this out : Font-Awesome5 Power Tranforms

Ajax call Into MVC Controller- Url Issue

Simple way to access the Url Try this Code

 $.ajax({
     type: "POST",
      url: '/Controller/Search', 
     data: "{queryString:'" + searchVal + "'}",
     contentType: "application/json; charset=utf-8",
     dataType: "html",
     success: function (data) {
     alert("here" + data.d.toString());
    });

Extract data from XML Clob using SQL from Oracle Database

This should work

SELECT EXTRACTVALUE(column_name, '/DCResponse/ContextData/Decision') FROM traptabclob;

I have assumed the ** were just for highlighting?

Empty set literal?

Just to extend the accepted answer:

From version 2.7 and 3.1 python has got set literal {} in form of usage {1,2,3}, but {} itself still used for empty dict.

Python 2.7 (first line is invalid in Python <2.7)

>>> {1,2,3}.__class__
<type 'set'>
>>> {}.__class__
<type 'dict'>

Python 3.x

>>> {1,2,3}.__class__
<class 'set'>
>>> {}.__class__
<class 'dict'>

More here: https://docs.python.org/3/whatsnew/2.7.html#other-language-changes

How to pass model attributes from one Spring MVC controller to another controller?

I had same problem.

With RedirectAttributes after refreshing page, my model attributes from first controller have been lost. I was thinking that is a bug, but then i found solution. In first controller I add attributes in ModelMap and do this instead of "redirect":

return "forward:/nameOfView";

This will redirect to your another controller and also keep model attributes from first one.

I hope this is what are you looking for. Sorry for my English

Add Foreign Key relationship between two Databases

The short answer is that SQL Server (as of SQL 2008) does not support cross database foreign keys--as the error message states.

While you cannot have declarative referential integrity (the FK), you can reach the same goal using triggers. It's a bit less reliable, because the logic you write may have bugs, but it will get you there just the same.

See the SQL docs @ http://msdn.microsoft.com/en-us/library/aa258254%28v=sql.80%29.aspx Which state:

Triggers are often used for enforcing business rules and data integrity. SQL Server provides declarative referential integrity (DRI) through the table creation statements (ALTER TABLE and CREATE TABLE); however, DRI does not provide cross-database referential integrity. To enforce referential integrity (rules about the relationships between the primary and foreign keys of tables), use primary and foreign key constraints (the PRIMARY KEY and FOREIGN KEY keywords of ALTER TABLE and CREATE TABLE). If constraints exist on the trigger table, they are checked after the INSTEAD OF trigger execution and prior to the AFTER trigger execution. If the constraints are violated, the INSTEAD OF trigger actions are rolled back and the AFTER trigger is not executed (fired).

There is also an OK discussion over at SQLTeam - http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=31135

ADB error: cannot connect to daemon

Check your firewall and antivirus for permissions for Android Debugger Bridge (adb.exe).

How to access static resources when mapping a global front controller servlet on /*

Map the controller servlet on a more specific url-pattern like /pages/*, put the static content in a specific folder like /static and create a Filter listening on /* which transparently continues the chain for any static content and dispatches requests to the controller servlet for other content.

In a nutshell:

<filter>
    <filter-name>filter</filter-name>
    <filter-class>com.example.Filter</filter-class>
</filter>
<filter-mapping>
    <filter-name>filter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<servlet>
    <servlet-name>controller</servlet-name>
    <servlet-class>com.example.Controller</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>controller</servlet-name>
    <url-pattern>/pages/*</url-pattern>
</servlet-mapping>

with the following in filter's doFilter():

HttpServletRequest req = (HttpServletRequest) request;
String path = req.getRequestURI().substring(req.getContextPath().length());

if (path.startsWith("/static")) {
    chain.doFilter(request, response); // Goes to default servlet.
} else {
    request.getRequestDispatcher("/pages" + path).forward(request, response);
}

No, this does not end up with /pages in browser address bar. It's fully transparent. You can if necessary make "/static" and/or "/pages" an init-param of the filter.

How to undo a git merge with conflicts

Assuming you are using the latest git,

git merge --abort

How to tag docker image with docker-compose

you can try:

services:
  nameis:
    container_name: hi_my
    build: .
    image: hi_my_nameis:v1.0.0

Adding two Java 8 streams, or an extra element to a stream

Just do:

Stream.of(stream1, stream2, Stream.of(element)).flatMap(identity());

where identity() is a static import of Function.identity().

Concatenating multiple streams into one stream is the same as flattening a stream.

However, unfortunately, for some reason there is no flatten() method on Stream, so you have to use flatMap() with the identity function.

jQuery get mouse position within an element

This solution supports all major browsers including IE. It also takes care of scrolling. First, it retrieves the position of the element relative to the page efficiently, and without using a recursive function. Then it gets the x and y of the mouse click relative to the page and does the subtraction to get the answer which is the position relative to the element (the element can be an image or div for example):

function getXY(evt) {
    var element = document.getElementById('elementId');  //replace elementId with your element's Id.
    var rect = element.getBoundingClientRect();
    var scrollTop = document.documentElement.scrollTop?
                    document.documentElement.scrollTop:document.body.scrollTop;
    var scrollLeft = document.documentElement.scrollLeft?                   
                    document.documentElement.scrollLeft:document.body.scrollLeft;
    var elementLeft = rect.left+scrollLeft;  
    var elementTop = rect.top+scrollTop;

        if (document.all){ //detects using IE   
            x = event.clientX+scrollLeft-elementLeft; //event not evt because of IE
            y = event.clientY+scrollTop-elementTop;
        }
        else{
            x = evt.pageX-elementLeft;
            y = evt.pageY-elementTop;
    }

Equivalent of waitForVisible/waitForElementPresent in Selenium WebDriver tests using Java?

Another way to wait for maximum of certain amount say 10 seconds of time for the element to be displayed as below:

(new WebDriverWait(driver, 10)).until(new ExpectedCondition<Boolean>() {
            public Boolean apply(WebDriver d) {
                return d.findElement(By.id("<name>")).isDisplayed();

            }
        });

HTTP GET with request body

You can either send a GET with a body or send a POST and give up RESTish religiosity (it's not so bad, 5 years ago there was only one member of that faith -- his comments linked above).

Neither are great decisions, but sending a GET body may prevent problems for some clients -- and some servers.

Doing a POST might have obstacles with some RESTish frameworks.

Julian Reschke suggested above using a non-standard HTTP header like "SEARCH" which could be an elegant solution, except that it's even less likely to be supported.

It might be most productive to list clients that can and cannot do each of the above.

Clients that cannot send a GET with body (that I know of):

  • XmlHTTPRequest Fiddler

Clients that can send a GET with body:

  • most browsers

Servers & libraries that can retrieve a body from GET:

  • Apache
  • PHP

Servers (and proxies) that strip a body from GET:

  • ?

Javascript use variable as object name

The object exists in some scope, so you can almost always access the variable via this syntax:

var objname = "myobject";
containing_scope_reference[objname].some_property = 'some value';

The only place where this gets tricky is when you are in a closed scope and you want access to a top-level local variable. When you have something like this:

(function(){
    var some_variable = {value: 25};
    var x = "some_variable";
    console.log(this[x], window[x]); // Doesn't work
})();

You can get around that by using eval instead to access the current scope chain ... but I don't recommend it unless you've done a lot of testing and you know that that's the best way to go about things.

(function(){
    var some_variable = {value: 25};
    var x = "some_variable";
    eval(x).value = 42;
    console.log(some_variable); // Works
})();

Your best bet is to have a reference to a name in an always-going-to-be-there object (like this in the global scope or a private top-level variable in a local scope) and put everything else in there.

Thus:

var my_outer_variable = {};
var outer_pointer = 'my_outer_variable';
// Reach my_outer_variable with this[outer_pointer]
// or window[outer_pointer]

(function(){
    var my_inner_scope = {'my_inner_variable': {} };
    var inner_pointer = 'my_inner_variable';
    // Reach my_inner_variable by using
    // my_inner_scope[inner_pointer]
})();

grep for special characters in Unix

Try vi with the -b option, this will show special end of line characters (I typically use it to see windows line endings in a txt file on a unix OS)

But if you want a scripted solution obviously vi wont work so you can try the -f or -e options with grep and pipe the result into sed or awk. From grep man page:

Matcher Selection -E, --extended-regexp Interpret PATTERN as an extended regular expression (ERE, see below). (-E is specified by POSIX.)

   -F, --fixed-strings
          Interpret PATTERN as a list of fixed strings, separated by newlines, any of which is to be matched.  (-F is specified
          by POSIX.)

How does bitshifting work in Java?

You can't write binary literals like 00101011 in Java so you can write it in hexadecimal instead:

byte x = 0x2b;

To calculate the result of x >> 2 you can then just write exactly that and print the result.

System.out.println(x >> 2);

SELECT last id, without INSERT

You could descendingly order the tabele by id and limit the number of results to one:

SELECT id FROM tablename ORDER BY id DESC LIMIT 1

BUT: ORDER BY rearranges the entire table for this request. So if you have a lot of data and you need to repeat this operation several times, I would not recommend this solution.

How can I get the last day of the month in C#?

DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month)

How to change button color with tkinter

Another way to change color of a button if you want to do multiple operations along with color change. Using the Tk().after method and binding a change method allows you to change color and do other operations.

Label.destroy is another example of the after method.

    def export_win():
        //Some Operation
        orig_color = export_finding_graph.cget("background")
        export_finding_graph.configure(background = "green")

        tt = "Exported"
        label = Label(tab1_closed_observations, text=tt, font=("Helvetica", 12))
        label.grid(row=0,column=0,padx=10,pady=5,columnspan=3)

        def change(orig_color):
            export_finding_graph.configure(background = orig_color)

        tab1_closed_observations.after(1000, lambda: change(orig_color))
        tab1_closed_observations.after(500, label.destroy)


    export_finding_graph = Button(tab1_closed_observations, text='Export', command=export_win)
    export_finding_graph.grid(row=6,column=4,padx=70,pady=20,sticky='we',columnspan=3)

You can also revert to the original color.

MySQL root password change

Tried the answer from @kta but didn't work for me.

I am using MySQL 8.0

This worked for me:

mysql> SET PASSWORD FOR 'root'@'localhost' = 'yourpassword'

How do I detect a click outside an element?

This works for me

$("body").mouseup(function(e) {
    var subject = $(".main-menu");
    if(e.target.id != subject.attr('id') && !subject.has(e.target).length) {
        $('.sub-menu').hide();
    }
});

What's a redirect URI? how does it apply to iOS app for OAuth2.0?

redirected uri is the location where the user will be redirected after successfully login to your app. for example to get access token for your app in facebook you need to subimt redirected uri which is nothing only the app Domain that your provide when you create your facebook app.

How to handle onchange event on input type=file in jQuery?

Try to use this:

HTML:

<input ID="fileUpload1" runat="server" type="file">

JavaScript:

$("#fileUpload1").on('change',function() {
    alert('Works!!');
});

?

How do I rename a repository on GitHub?

Note that since May 2013 ("Repository redirects are here!"), you can rename your GitHub repo without breaking any links:

We're happy to announce that starting today, we'll automatically redirect all requests for previous repository locations to their new home in these circumstances. There's nothing special you have to do. Just rename away and we'll take care of the rest.

As a special bonus, we'll also be servicing all Git clone, fetch, and push requests from previous repository locations.

That means you don't even have to git remote set-url (change the url of your remote GitHub repo) on your local cloned repo!
Although Gabriel notes in the comments that the official GitHub help page strongly recommends that you do so:

to reduce confusion, we strongly recommend updating any existing local clones to point to the new repository URL. You can do this by using git remote on the command line:

git remote set-url origin new_url

Beware though:

GitHub Pages sites are not automatically redirected when their repositories are renamed at this time.
Renaming a Pages repository will continue to break any existing links to content hosted on the github.io domain or custom domains.

Plus, the user still owns the namespace: if he/she creates a new repo using the old name of the renamed repo, that redirection (for said renamed repo) will stop working.

Execute php file from another php

exec('wget http://<url to the php script>') worked for me.

It enable me to integrate two php files that were designed as web pages and run them as code to do work without affecting the calling page

Setting onSubmit in React.js

<form onSubmit={(e) => {this.doSomething(); e.preventDefault();}}></form>

it work fine for me

Why is pydot unable to find GraphViz's executables in Windows 8?

I am running a Windows 10 machine and had some problems, too. I installed graphviz via msi installer. Adding via System settings did not work for me.

I removed the installation with the msi and used chocolatey, a windows package manager. Removing the installed version is necessary, otherwise chocolatey won't install.

Now it runs fine. I would recommend doing it this way.

How do I set environment variables from Java?

Kotlin implementation I recently made based on Edward's answer:

fun setEnv(newEnv: Map<String, String>) {
    val unmodifiableMapClass = Collections.unmodifiableMap<Any, Any>(mapOf()).javaClass
    with(unmodifiableMapClass.getDeclaredField("m")) {
        isAccessible = true
        @Suppress("UNCHECKED_CAST")
        get(System.getenv()) as MutableMap<String, String>
    }.apply {
        clear()
        putAll(newEnv)
    }
}

"Cross origin requests are only supported for HTTP." error when loading a local file

Ran in to this today.

I wrote some code that looked like this:

app.controller('ctrlr', function($scope, $http){
    $http.get('localhost:3000').success(function(data) {
        $scope.stuff = data;
    });
});

...but it should've looked like this:

app.controller('ctrlr', function($scope, $http){
    $http.get('http://localhost:3000').success(function(data) {
        $scope.stuff = data;
    });
});

The only difference was the lack of http:// in the second snippet of code.

Just wanted to put that out there in case there are others with a similar issue.

Find and replace words/lines in a file

Any decent text editor has a search&replace facility that supports regular expressions.

If however, you have reason to reinvent the wheel in Java, you can do:

Path path = Paths.get("test.txt");
Charset charset = StandardCharsets.UTF_8;

String content = new String(Files.readAllBytes(path), charset);
content = content.replaceAll("foo", "bar");
Files.write(path, content.getBytes(charset));

This only works for Java 7 or newer. If you are stuck on an older Java, you can do:

String content = IOUtils.toString(new FileInputStream(myfile), myencoding);
content = content.replaceAll(myPattern, myReplacement);
IOUtils.write(content, new FileOutputStream(myfile), myencoding);

In this case, you'll need to add error handling and close the streams after you are done with them.

IOUtils is documented at http://commons.apache.org/proper/commons-io/javadocs/api-release/org/apache/commons/io/IOUtils.html

How can I return the difference between two lists?

First convert list to sets.

// create an empty set 
Set<T> set = new HashSet<>(); 

// Add each element of list into the set 
for (T t : list) 
    set.add(t); 

You can use Sets.difference(Set1, Set2), which returns extra items present in Set1.
You can use Sets.difference(Set2, Set1), which returns extra items present in Set2.

getting "No column was specified for column 2 of 'd'" in sql server cte?

Msg 8155, Level 16, State 2, Line 1 No column was specified for column 1 of 'd'. Msg 8155, Level 16, State 2, Line 1 No column was specified for column 2 of 'd'. ANSWER:

ROUND(AVG(CAST(column_name AS FLOAT)), 2) as column_name

how to get docker-compose to use the latest image from repository

The docker-compose documentation for the 'up' command clearly states that it updates the container should the image be changed since the last 'up' was performed:

If there are existing containers for a service, and the service’s configuration or image was changed after the container’s creation, docker-compose up picks up the changes by stopping and recreating the containers (preserving mounted volumes).

So by using 'stop' followed by 'pull' and then 'up' this should therefore avoid issues of lost volumes for the running containers, except of course, for containers whose images have been updated.

I am currently experimenting with this process and will include my results in this comment shortly.

How to replace case-insensitive literal substrings in Java

Regular expressions are quite complex to manage due to the fact that some characters are reserved: for example, "foo.bar".replaceAll(".") produces an empty string, because the dot means "anything" If you want to replace only the point should be indicated as a parameter "\\.".

A simpler solution is to use StringBuilder objects to search and replace text. It takes two: one that contains the text in lowercase version while the second contains the original version. The search is performed on the lowercase contents and the index detected will also replace the original text.

public class LowerCaseReplace 
{
    public static String replace(String source, String target, String replacement)
    {
        StringBuilder sbSource = new StringBuilder(source);
        StringBuilder sbSourceLower = new StringBuilder(source.toLowerCase());
        String searchString = target.toLowerCase();

        int idx = 0;
        while((idx = sbSourceLower.indexOf(searchString, idx)) != -1) {
            sbSource.replace(idx, idx + searchString.length(), replacement);
            sbSourceLower.replace(idx, idx + searchString.length(), replacement);
            idx+= replacement.length();
        }
        sbSourceLower.setLength(0);
        sbSourceLower.trimToSize();
        sbSourceLower = null;

        return sbSource.toString();
    }


    public static void main(String[] args)
    {
        System.out.println(replace("xXXxyyyXxxuuuuoooo", "xx", "**"));
        System.out.println(replace("FOoBaR", "bar", "*"));
    }
}

Linux command: How to 'find' only text files?

Why is it unhandy? If you need to use it often, and don't want to type it every time just define a bash function for it:

function findTextInAsciiFiles {
    # usage: findTextInAsciiFiles DIRECTORY NEEDLE_TEXT
    find "$1" -type f -exec grep -l "$2" {} \; -exec file {} \; | grep text
}

put it in your .bashrc and then just run:

findTextInAsciiFiles your_folder "needle text"

whenever you want.


EDIT to reflect OP's edit:

if you want to cut out mime informations you could just add a further stage to the pipeline that filters out mime informations. This should do the trick, by taking only what comes before :: cut -d':' -f1:

function findTextInAsciiFiles {
    # usage: findTextInAsciiFiles DIRECTORY NEEDLE_TEXT
    find "$1" -type f -exec grep -l "$2" {} \; -exec file {} \; | grep text | cut -d ':' -f1
}

Adding devices to team provisioning profile

Note that testers are no longer added via UUID in the new Apple TestFlight.

Test Flight builds now require an App Store Distribution Provisioning Profile. The portal does not allow UUIDs to be added to this type of provisioning profile.

Instead, add "Internal Testers" via iTunes Connect:

Internal testers are iTunes Connect users with the Admin or Technical role. They can be added in Users and Roles.

After adding a user, be sure to click on their name and flip the "Internal Tester" switch.

Internal Tester Toggle Switch

Then, go to App > Prerelease > Internal Testers and invite them to the build.

Fastest way(s) to move the cursor on a terminal command line?

Use the mouse

Sometimes, the easiest way to edit a commandline is using a mouse. Some previous answers give a command to open your current line in your $EDITOR. For me (zhs with grml config) that combination is Alt+e. If you enable mouse in your editor, you can make use of it.

To enable mouse in Vim, add this to your ~/.vimrc

set mouse=a
set ttymouse=xterm2

If you then want to do a text selection in terminal (instead of passing the mouseclick to vim), hold Shift when you click; this is terminal specific, of course.

Sysadmins should not be afraid of the mouse.

Attempted to read or write protected memory

The problem may be due to mixed build platforms DLLs in the project. i.e You build your project to Any CPU but have some DLLs in the project already built for x86 platform. These will cause random crashes because of different memory mapping of 32bit and 64bit architecture. If all the DLLs are built for one platform the problem can be solved. For safety try bulinding for 32bit x86 architecture because it is the most compatible.

How to detect if CMD is running as Administrator/has elevated privileges?

the solution:

at >nul
if %ErrorLevel% equ 0 ( echo Administrator ) else ( echo NOT Administrator )

does not work under Windows 10

for all versions of Windows can be do so:

openfiles >nul 2>&1
if %ErrorLevel% equ 0 ( echo Administrator ) else ( echo NOT Administrator )

java.lang.ClassNotFoundException: org.springframework.boot.SpringApplication Maven

In my case, I did remove maven nature manually from .project file while having the project opened in Eclipse. So what I'd to do was to add maven nature again using the contextual menu (roght click on the project > configuration > add maven nature). Afterwards, everything worked nice :D

How to increase code font size in IntelliJ?

To change font size using the keyboard

In Windows or Linux press Ctrl+Shift+A

In MAC press CMD+Shift+A

In the popup frame, type Increase font size or Decrease font size, and then click Enter.

Font grows larger or smaller.

How to use pull to refresh in Swift?

This is how I made it work using Xcode 7.2 which I think is a major bug. I'm using it inside my UITableViewController inside my viewWillAppear

refreshControl = UIRefreshControl()
refreshControl!.addTarget(self, action: "configureMessages", forControlEvents: .ValueChanged)
refreshControl!.beginRefreshing()

configureMessages()

func configureMessages() {
    // configuring messages logic here

    self.refreshControl!.endRefreshing()
}

As you can see, I literally have to call the configureMessage() method after setting up my UIRefreshControl then after that, subsequent refreshes will work fine.

Can an abstract class have a constructor?

Yes, an abstract class can have a constructor. Consider this:

abstract class Product { 
    int multiplyBy;
    public Product( int multiplyBy ) {
        this.multiplyBy = multiplyBy;
    }

    public int mutiply(int val) {
       return multiplyBy * val;
    }
}

class TimesTwo extends Product {
    public TimesTwo() {
        super(2);
    }
}

class TimesWhat extends Product {
    public TimesWhat(int what) {
        super(what);
    }
}

The superclass Product is abstract and has a constructor. The concrete class TimesTwo has a constructor that just hardcodes the value 2. The concrete class TimesWhat has a constructor that allows the caller to specify the value.

Abstract constructors will frequently be used to enforce class constraints or invariants such as the minimum fields required to setup the class.

NOTE: As there is no default (or no-arg) constructor in the parent abstract class, the constructor used in subclass must explicitly call the parent constructor.

How do I start a program with arguments when debugging?

for .NET Core console apps you can do this 2 ways - from the launchsettings.json or the properties menu.

Launchsettings.json

enter image description here

or right click the project > properties > debug tab on left

see "Application Arguments:"

  • this is " " (space) delimited, no need for any commas. just start typing. each space " " will represent a new input parameter.
  • (whatever changes you make here will be reflected in the launchsettings.json file...)

enter image description here

Kafka consumer list

Use kafka-consumer-groups.sh

For example

bin/kafka-consumer-groups.sh  --list --bootstrap-server localhost:9092

bin/kafka-consumer-groups.sh --describe --group mygroup --bootstrap-server localhost:9092

Get and Set Screen Resolution

In C# this is how to get the resolution Screen:

button click or form load:

string screenWidth = Screen.PrimaryScreen.Bounds.Width.ToString();
string screenHeight = Screen.PrimaryScreen.Bounds.Height.ToString();
Label1.Text = ("Resolution: " + screenWidth + "x" + screenHeight);

Gridview get Checkbox.Checked value

For run all lines of GridView don't use for loop, use foreach loop like:

foreach (GridViewRow row in yourGridName.Rows) //Running all lines of grid
{
    if (row.RowType == DataControlRowType.DataRow)
    {
         CheckBox chkRow = (row.Cells[0].FindControl("chkRow") as CheckBox);

         if (chkRow.Checked)
         {
              //if checked do something
         }
    }
}

How to execute a file within the python interpreter?

python -c "exec(open('main.py').read())"

Polymorphism vs Overriding vs Overloading

Polymorphism is more likely as far as it's meaning is concerned ... to OVERRIDING in java

It's all about different behavior of the SAME object in different situations(In programming way ... you can call different ARGUMENTS)

I think the example below will help you to understand ... Though it's not PURE java code ...

     public void See(Friend)
     {
        System.out.println("Talk");
     }

But if we change the ARGUMENT ... the BEHAVIOR will be changed ...

     public void See(Enemy)
     {
        System.out.println("Run");
     }

The Person(here the "Object") is same ...

How do I disable "missing docstring" warnings at a file-level in Pylint?

Edit file "C:\Users\Your User\AppData\Roaming\Code\User\settings.json" and add these python.linting.pylintArgs lines at the end as shown below:

{
    "team.showWelcomeMessage": false,
    "python.dataScience.sendSelectionToInteractiveWindow": true,
    "git.enableSmartCommit": true,
    "powershell.codeFormatting.useCorrectCasing": true,
    "files.autoSave": "onWindowChange",
    "python.linting.pylintArgs": [
        "--load-plugins=pylint_django",
        "--errors-only"
    ],
}

Finding all possible combinations of numbers to reach a given sum

PHP Version, as inspired by Keith Beller's C# version.

bala's PHP version did not work for me, because I did not need to group numbers. I wanted a simpler implementation with one target value, and a pool of numbers. This function will also prune any duplicate entries.

/**
 * Calculates a subset sum: finds out which combinations of numbers
 * from the numbers array can be added together to come to the target
 * number.
 * 
 * Returns an indexed array with arrays of number combinations.
 * 
 * Example: 
 * 
 * <pre>
 * $matches = subset_sum(array(5,10,7,3,20), 25);
 * </pre>
 * 
 * Returns:
 * 
 * <pre>
 * Array
 * (
 *   [0] => Array
 *   (
 *       [0] => 3
 *       [1] => 5
 *       [2] => 7
 *       [3] => 10
 *   )
 *   [1] => Array
 *   (
 *       [0] => 5
 *       [1] => 20
 *   )
 * )
 * </pre>
 * 
 * @param number[] $numbers
 * @param number $target
 * @param array $part
 * @return array[number[]]
 */
function subset_sum($numbers, $target, $part=null)
{
    // we assume that an empty $part variable means this
    // is the top level call.
    $toplevel = false;
    if($part === null) {
        $toplevel = true;
        $part = array();
    }

    $s = 0;
    foreach($part as $x) 
    {
        $s = $s + $x;
    }

    // we have found a match!
    if($s == $target) 
    {
        sort($part); // ensure the numbers are always sorted
        return array(implode('|', $part));
    }

    // gone too far, break off
    if($s >= $target) 
    {
        return null;
    }

    $matches = array();
    $totalNumbers = count($numbers);

    for($i=0; $i < $totalNumbers; $i++) 
    {
        $remaining = array();
        $n = $numbers[$i];

        for($j = $i+1; $j < $totalNumbers; $j++) 
        {
            $remaining[] = $numbers[$j];
        }

        $part_rec = $part;
        $part_rec[] = $n;

        $result = subset_sum($remaining, $target, $part_rec);
        if($result) 
        {
            $matches = array_merge($matches, $result);
        }
    }

    if(!$toplevel) 
    {
        return $matches;
    }

    // this is the top level function call: we have to
    // prepare the final result value by stripping any
    // duplicate results.
    $matches = array_unique($matches);
    $result = array();
    foreach($matches as $entry) 
    {
        $result[] = explode('|', $entry);
    }

    return $result;
}

Can I run a 64-bit VMware image on a 32-bit machine?

You can if your processor is 64-bit and Virtualization Technology (VT) extension is enabled (it can be switched off in BIOS). You can't do it on 32-bit processor.

To check this under Linux you just need to look into /proc/cpuinfo file. Just look for the appropriate flag (vmx for Intel processor or svm for AMD processor)

egrep '(vmx|svm)' /proc/cpuinfo

To check this under Windows you need to use a program like CPU-Z which will display your processor architecture and supported extensions.

Operator overloading ==, !=, Equals

In fact, this is a "how to" subject. So, here is the reference implementation:

    public class BOX
    {
        double height, length, breadth;

        public static bool operator == (BOX b1, BOX b2)
        {
            if ((object)b1 == null)
                return (object)b2 == null;

            return b1.Equals(b2);
        }

        public static bool operator != (BOX b1, BOX b2)
        {
            return !(b1 == b2);
        }

        public override bool Equals(object obj)
        {
            if (obj == null || GetType() != obj.GetType())
                return false;

            var b2 = (BOX)obj;
            return (length == b2.length && breadth == b2.breadth && height == b2.height);
        }

        public override int GetHashCode()
        {
            return height.GetHashCode() ^ length.GetHashCode() ^ breadth.GetHashCode();
        }
    }

REF: https://msdn.microsoft.com/en-us/library/336aedhh(v=vs.100).aspx#Examples

UPDATE: the cast to (object) in the operator == implementation is important, otherwise, it would re-execute the operator == overload, leading to a stackoverflow. Credits to @grek40.

This (object) cast trick is from Microsoft String == implementaiton. SRC: https://github.com/Microsoft/referencesource/blob/master/mscorlib/system/string.cs#L643

Format number as percent in MS SQL Server

M.Ali's answer could be modified as

select Cast(Cast((37.0/38.0)*100 as decimal(18,2)) as varchar(5)) + ' %' as Percentage

From inside of a Docker container, how do I connect to the localhost of the machine?

This worked for me on an NGINX/PHP-FPM stack without touching any code or networking where the app's just expecting to be able to connect to localhost

Mount mysqld.sock from the host to inside the container.

Find the location of the mysql.sock file on the host running mysql:
netstat -ln | awk '/mysql(.*)?\.sock/ { print $9 }'

Mount that file to where it's expected in the docker:
docker run -v /hostpath/to/mysqld.sock:/containerpath/to/mysqld.sock

Possible locations of mysqld.sock:

/tmp/mysqld.sock
/var/run/mysqld/mysqld.sock 
/var/lib/mysql/mysql.sock
/Applications/MAMP/tmp/mysql/mysql.sock # if running via MAMP

Convert string (without any separator) to list

A python string is a list of characters. You can iterate over it right now!

justdigits = ""
for char in string:
    if char.isdigit():
        justdigits += str(char)

INNER JOIN vs LEFT JOIN performance in SQL Server

I found something interesting in SQL server when checking if inner joins are faster than left joins.

If you dont include the items of the left joined table, in the select statement, the left join will be faster than the same query with inner join.

If you do include the left joined table in the select statement, the inner join with the same query was equal or faster than the left join.

MetadataException when using Entity Framework Entity Connection

I moved my Database First DataModel to a different project midway through development. Poor planning (or lack there of) on my part.

Initially I had a solution with one project. Then I added another project to the solution and recreated my Database First DataModel from the Sql Server Dataase.

To fix the problem - MetadataException when using Entity Framework Entity Connection. I copied my the ConnectionString from the new Project Web.Config to the original project Web.Config. However, this occurred after I updated my all the references in the original project to new DataModel project.

File Not Found when running PHP with Nginx

In my case the PHP-script itself returned 404 code. Had nothing to do with nginx.

git replace local version with remote version

Use the -s or --strategy option combined with the -X option. In your specific question, you want to keep all of the remote files and replace the local files of the same name.

Replace conflicts with the remote version

git merge -s recursive -Xtheirs upstream/master  

will use the remote repo version of all conflicting files.

Replace conflicts with the local version

git merge -s recursive -Xours upstream/master

will use the local repo version of all conflicting files.

Hexadecimal value 0x00 is a invalid character

In my case, it took some digging, but found it.

My Context

I'm looking at exception/error logs from the website using Elmah. Elmah returns the state of the server at the of time the exception, in the form of a large XML document. For our reporting engine I pretty-print the XML with XmlWriter.

During a website attack, I noticed that some xmls weren't parsing and was receiving this '.', hexadecimal value 0x00, is an invalid character. exception.

NON-RESOLUTION: I converted the document to a byte[] and sanitized it of 0x00, but it found none.

When I scanned the xml document, I found the following:

...
<form>
...
<item name="SomeField">
   <value
     string="C:\boot.ini&#x0;.htm" />
 </item>
...

There was the nul byte encoded as an html entity &#x0; !!!

RESOLUTION: To fix the encoding, I replaced the &#x0; value before loading it into my XmlDocument, because loading it will create the nul byte and it will be difficult to sanitize it from the object. Here's my entire process:

XmlDocument xml = new XmlDocument();
details.Xml = details.Xml.Replace("&#x0;", "[0x00]");  // in my case I want to see it, otherwise just replace with ""
xml.LoadXml(details.Xml);

string formattedXml = null;

// I have this in a helper function, but for this example I have put it in-line
StringBuilder sb = new StringBuilder();
XmlWriterSettings settings = new XmlWriterSettings {
    OmitXmlDeclaration = true,
    Indent = true,
    IndentChars = "\t",
    NewLineHandling = NewLineHandling.None,
};
using (XmlWriter writer = XmlWriter.Create(sb, settings)) {
    xml.Save(writer);
    formattedXml = sb.ToString();
}

LESSON LEARNED: sanitize for illegal bytes using the associated html entity, if your incoming data is html encoded on entry.

Create table with jQuery - append


i prefer the most readable and extensible way using jquery.
Also, you can build fully dynamic content on the fly.
Since jquery version 1.4 you can pass attributes to elements which is,
imho, a killer feature. Also the code can be kept cleaner.

$(function(){

        var tablerows = new Array();

        $.each(['result1', 'result2', 'result3'], function( index, value ) {
            tablerows.push('<tr><td>' + value + '</td></tr>');
        });

        var table =  $('<table/>', {
           html:  tablerows
       });

        var div = $('<div/>', {
            id: 'here_table',
            html: table
        });

        $('body').append(div);

    });

Addon: passing more than one "html" tag you've to use array notation like: e.g.

var div = $('<div/>', {
            id: 'here_table',
            html: [ div1, div2, table ]
        });

best Rgds.
Franz

Access parent URL from iframe

You're correct. Subdomains are still considered separate domains when using iframes. It's possible to pass messages using postMessage(...), but other JS APIs are intentionally made inaccessible.

It's also still possible to get the URL depending on the context. See other answers for more details.

Creating folders inside a GitHub repository without using Git

Another thing you can do is just drag a folder from your computer into the GitHub repository page. This folder does have to have at least 1 item in it, though.

The module ".dll" was loaded but the entry-point was not found

I had this problem and

dumpbin /exports mydll.dll

and

depends mydll.dll

showed 'DllRegisterServer'.

The problem was that there was another DLL in the system that had the same name. After renaming mydll the registration succeeded.

How to only find files in a given directory, and ignore subdirectories using bash

I got here with a bit more general problem - I wanted to find files in directories matching pattern but not in their subdirectories.

My solution (assuming we're looking for all cpp files living directly in arch directories):

find . -path "*/arch/*/*" -prune -o -path "*/arch/*.cpp" -print

I couldn't use maxdepth since it limited search in the first place, and didn't know names of subdirectories that I wanted to exclude.

Create a button programmatically and set a background image

let btnRight=UIButton.buttonWithType(UIButtonType.Custom) as UIButton
btnRight.frame=CGRectMake(0, 0, 35, 35)
btnRight.setBackgroundImage(UIImage(named: "menu.png"), forState: UIControlState.Normal)
btnRight.setTitle("Right", forState: UIControlState.Normal)
btnRight.tintColor=UIColor.blackColor()

Escape curly brace '{' in String.Format

Use double braces {{ or }} so your code becomes:

sb.AppendLine(String.Format("public {0} {1} {{ get; private set; }}", 
prop.Type, prop.Name));

// For prop.Type of "Foo" and prop.Name of "Bar", the result would be:
// public Foo Bar { get; private set; }

How can I write these variables into one line of code in C#?

Look into composite formatting:

Console.WriteLine("{0}.{1}.{2}", mon, da, yer);

You could also write (although it's not really recommended):

Console.WriteLine(mon + "." + da + "." + yer);

And, with the release of C# 6.0, you have string interpolation expressions:

Console.WriteLine($"{mon}.{da}.{yer}");  // note the $ prefix.

MySQL: determine which database is selected?

Just use mysql_query (or mysqli_query, even better, or use PDO, best of all) with:

SELECT DATABASE() FROM DUAL;

Addendum:

There is much discussion over whether or not FROM DUAL should be included in this or not. On a technical level, it is a holdover from Oracle and can safely be removed. If you are inclined, you can use the following instead:

SELECT DATABASE();

That said, it is perhaps important to note, that while FROM DUAL does not actually do anything, it is valid MySQL syntax. From a strict perspective, including braces in a single line conditional in JavaScript also does not do anything, but it is still a valid practice.

How to pass a file path which is in assets folder to File(String path)?

Unless you unpack them, assets remain inside the apk. Accordingly, there isn't a path you can feed into a File. The path you've given in your question will work with/in a WebView, but I think that's a special case for WebView.

You'll need to unpack the file or use it directly.

If you have a Context, you can use context.getAssets().open("myfoldername/myfilename"); to open an InputStream on the file. With the InputStream you can use it directly, or write it out somewhere (after which you can use it with File).

Which loop is faster, while or for?

I also tried to benchmark the different kinds of loop in C#. I used the same code as Shane, but I also tried with a do-while and found it to be the fastest. This is the code:

using System;
using System.Diagnostics;


public class Program
{
    public static void Main()
    {
        int max = 9999999;
        Stopwatch stopWatch = new Stopwatch();

        Console.WriteLine("Do While Loop: ");
        stopWatch.Start();
        DoWhileLoop(max);
        stopWatch.Stop();
        DisplayElapsedTime(stopWatch.Elapsed);
        Console.WriteLine("");
        Console.WriteLine("");

        Console.WriteLine("While Loop: ");
        stopWatch.Start();
        WhileLoop(max);
        stopWatch.Stop();
        DisplayElapsedTime(stopWatch.Elapsed);
        Console.WriteLine("");
        Console.WriteLine("");

        Console.WriteLine("For Loop: ");
        stopWatch.Start();
        ForLoop(max);
        stopWatch.Stop();
        DisplayElapsedTime(stopWatch.Elapsed);
    }

    private static void DoWhileLoop(int max)
    {
        int i = 0;
        do
        {
            //Performe Some Operation. By removing Speed increases
            var j = 10 + 10;
            j += 25;
            i++;
        } while (i <= max);
    }

    private static void WhileLoop(int max)
    {
        int i = 0;
        while (i <= max)
        {
            //Performe Some Operation. By removing Speed increases
            var j = 10 + 10;
            j += 25;
            i++;
        };
    }

    private static void ForLoop(int max)
    {
        for (int i = 0; i <= max; i++)
        {
            //Performe Some Operation. By removing Speed increases
            var j = 10 + 10;
            j += 25;
        }
    }

    private static void DisplayElapsedTime(TimeSpan ts)
    {
        string elapsedTime = String.Format("{0:00}:{1:00}:{2:00}.{3:00}", ts.Hours, ts.Minutes, ts.Seconds, ts.Milliseconds / 10);
        Console.WriteLine(elapsedTime, "RunTime");
    }
}

and these are the results of a live demo on DotNetFiddle:

Do While Loop:
00:00:00.06

While Loop:
00:00:00.13

For Loop:
00:00:00.27

Add an incremental number in a field in INSERT INTO SELECT query in SQL Server

You can use the row_number() function for this.

INSERT INTO PM_Ingrediants_Arrangements_Temp(AdminID, ArrangementID, IngrediantID, Sequence)
    SELECT @AdminID, @ArrangementID, PM_Ingrediants.ID,
            row_number() over (order by (select NULL))
    FROM PM_Ingrediants 
    WHERE PM_Ingrediants.ID IN (SELECT ID FROM GetIDsTableFromIDsList(@IngrediantsIDs)
                             )

If you want to start with the maximum already in the table then do:

INSERT INTO PM_Ingrediants_Arrangements_Temp(AdminID, ArrangementID, IngrediantID, Sequence)
    SELECT @AdminID, @ArrangementID, PM_Ingrediants.ID,
           coalesce(const.maxs, 0) + row_number() over (order by (select NULL))
    FROM PM_Ingrediants cross join
         (select max(sequence) as maxs from PM_Ingrediants_Arrangement_Temp) const
    WHERE PM_Ingrediants.ID IN (SELECT ID FROM GetIDsTableFromIDsList(@IngrediantsIDs)
                             )

Finally, you can just make the sequence column an auto-incrementing identity column. This saves the need to increment it each time:

create table PM_Ingrediants_Arrangement_Temp ( . . .
    sequence int identity(1, 1) -- and might consider making this a primary key too
    . . .
)

Best practice to call ConfigureAwait for all server-side code

I have some general thoughts about the implementation of Task:

  1. Task is disposable yet we are not supposed to use using.
  2. ConfigureAwait was introduced in 4.5. Task was introduced in 4.0.
  3. .NET Threads always used to flow the context (see C# via CLR book) but in the default implementation of Task.ContinueWith they do not b/c it was realised context switch is expensive and it is turned off by default.
  4. The problem is a library developer should not care whether its clients need context flow or not hence it should not decide whether flow the context or not.
  5. [Added later] The fact that there is no authoritative answer and proper reference and we keep fighting on this means someone has not done their job right.

I have got a few posts on the subject but my take - in addition to Tugberk's nice answer - is that you should turn all APIs asynchronous and ideally flow the context . Since you are doing async, you can simply use continuations instead of waiting so no deadlock will be cause since no wait is done in the library and you keep the flowing so the context is preserved (such as HttpContext).

Problem is when a library exposes a synchronous API but uses another asynchronous API - hence you need to use Wait()/Result in your code.

Sorting Characters Of A C++ String

There is a sorting algorithm in the standard library, in the header <algorithm>. It sorts inplace, so if you do the following, your original word will become sorted.

std::sort(word.begin(), word.end());

If you don't want to lose the original, make a copy first.

std::string sortedWord = word;
std::sort(sortedWord.begin(), sortedWord.end());

What is the difference between .py and .pyc files?

"A program doesn't run any faster when it is read from a ".pyc" or ".pyo" file than when it is read from a ".py" file; the only thing that's faster about ".pyc" or ".pyo" files is the speed with which they are loaded. "

http://docs.python.org/release/1.5.1p1/tut/node43.html

URL to load resources from the classpath in Java

You can also set the property programmatically during startup:

final String key = "java.protocol.handler.pkgs";
String newValue = "org.my.protocols";
if (System.getProperty(key) != null) {
    final String previousValue = System.getProperty(key);
    newValue += "|" + previousValue;
}
System.setProperty(key, newValue);

Using this class:

package org.my.protocols.classpath;

import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;

public class Handler extends URLStreamHandler {

    @Override
    protected URLConnection openConnection(final URL u) throws IOException {
        final URL resourceUrl = ClassLoader.getSystemClassLoader().getResource(u.getPath());
        return resourceUrl.openConnection();
    }
}

Thus you get the least intrusive way to do this. :) java.net.URL will always use the current value from the system properties.

How to download PDF automatically using js?

  1. for second point, get a full path to pdf file into some java variable. e.g. http://www.domain.com/files/filename.pdf

e.g. you're using php and $filepath contains pdf file path.

so you can write javascript like to to emulate download dialog box.

<script language="javascript">
    window.location.href = '<?php echo $filepath; ?>';
</script

Above code sends browser to pdf file by its url "http://www.domain.com/files/filename.pdf". So at last, browser will show download dialog box to where to save this file on your machine.

Expand/collapse section in UITableView in iOS

This action will happen in your didSelectRowAtIndexPath, when you will try to hide or show number of cell in a  section

first of all declare a global variable numberOfSectionInMoreInfo in .h file and in your viewDidLoad set suppose to numberOfSectionInMoreInfo = 4.

Now use following logic: 


 // More info link
        if(row == 3) {

            /*Logic: We are trying to hide/show the number of row into more information section */

            NSString *log= [NSString stringWithFormat:@"Number of section in more %i",numberOfSectionInMoreInfo];

            [objSpineCustomProtocol showAlertMessage:log];

            // Check if the number of rows are open or close in view
            if(numberOfSectionInMoreInfo > 4) {

                // close the more info toggle
                numberOfSectionInMoreInfo = 4;

            }else {

                // Open more info toggle
                numberOfSectionInMoreInfo = 9;

            }

            //reload this section
            [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:1] withRowAnimation:UITableViewRowAnimationFade];

//vKj

How to get HttpRequestMessage data

From this answer:

[HttpPost]
public void Confirmation(HttpRequestMessage request)
{
    var content = request.Content;
    string jsonContent = content.ReadAsStringAsync().Result;
}

Note: As seen in the comments, this code could cause a deadlock and should not be used. See this blog post for more detail.