Programs & Examples On #Inverse kinematics

Inverse kinematics refers to a set of algorithms used to compute joint parameters necessary to move a robotic arm to a particular position, or more generally to apply geometric constraints on a mechanism (e.g. moving the center of mass of a humanoid robot).

Push method in React Hooks (useState)?

To expand a little further, here are some common examples. Starting with:

const [theArray, setTheArray] = useState(initialArray);
const [theObject, setTheObject] = useState(initialObject);

Push element at end of array

setTheArray(prevArray => [...prevArray, newValue])

Push/update element at end of object

setTheObject(prevState => ({ ...prevState, currentOrNewKey: newValue}));

Push/update element at end of array of objects

setTheArray(prevState => [...prevState, {currentOrNewKey: newValue}]);

Push element at end of object of arrays

let specificArrayInObject = theObject.array.slice();
specificArrayInObject.push(newValue);
const newObj = { ...theObject, [event.target.name]: specificArrayInObject };
theObject(newObj);

Here are some working examples too. https://codesandbox.io/s/reacthooks-push-r991u

Time complexity of accessing a Python dict

You are not correct. dict access is unlikely to be your problem here. It is almost certainly O(1), unless you have some very weird inputs or a very bad hashing function. Paste some sample code from your application for a better diagnosis.

Why do many examples use `fig, ax = plt.subplots()` in Matplotlib/pyplot/python

In addition to the answers above, you can check the type of object using type(plt.subplots()) which returns a tuple, on the other hand, type(plt.subplot()) returns matplotlib.axes._subplots.AxesSubplot which you can't unpack.

What are file descriptors, explained in simple terms?

File descriptors are nothing but references for any open resource. As soon as you open a resource the kernel assumes you will be doing some operations on it. All the communication via your program and the resource happens over an interface and this interface is provided by the file-descriptor.

Since a process can open more than one resource, it is possible for a resource to have more than one file-descriptors.
You can view all file-descriptors linked to the process by simply running, ls -li /proc/<pid>/fd/ here pid is the process-id of your process

Eloquent Collection: Counting and Detect Empty

I think better to used

$result->isEmpty();

The isEmpty method returns true if the collection is empty; otherwise, false is returned.

Python executable not finding libpython shared library

I installed using the command:

./configure --prefix=/usr       \
            --enable-shared     \
            --with-system-expat \
            --with-system-ffi   \
            --enable-unicode=ucs4 &&

make

Now, as the root user:

make install &&
chmod -v 755 /usr/lib/libpython2.7.so.1.0

Then I tried to execute python and got the error:

/usr/local/bin/python: error while loading shared libraries: libpython2.7.so.1.0: cannot open shared object file: No such file or directory

Then, I logged out from root user and again tried to execute the Python and it worked successfully.

Reading Properties file in Java

Make sure that the file name is correct and that the file is actually in the class path. getResourceAsStream() will return null if this is not the case which causes the last line to throw the exception.

If myProp.properties is in the root directory of your project, use /myProp.properties instead.

Vertical Align Center in Bootstrap 4

you can vertically align your container by making the parent container flex and adding align-items:center:

body {
  display:flex;
  align-items:center;
}

Updated Pen

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 = [];
}

git: patch does not apply

Johannes Sixt from the [email protected] mailing list suggested using following command line arguments:

git apply --ignore-space-change --ignore-whitespace mychanges.patch

This solved my problem.

Creating a BAT file for python script

Just simply open a batch file that contains this two lines in the same folder of your python script:

somescript.py
pause

How to set and reference a variable in a Jenkinsfile

The error is due to that you're only allowed to use pipeline steps inside the steps directive. One workaround that I know is to use the script step and wrap arbitrary pipeline script inside of it and save the result in the environment variable so that it can be used later.

So in your case:

pipeline {
    agent any
    stages {
        stage("foo") {
            steps {
                script {
                    env.FILENAME = readFile 'output.txt'
                }
                echo "${env.FILENAME}"
            }
        }
    }
}

How to normalize a 2-dimensional numpy array in python less verbose?

normed_matrix = normalize(input_data, axis=1, norm='l1')
print(normed_matrix)

where input_data is the name of your 2D array

Creating a recursive method for Palindrome

Here is the code for palindrome check without creating many strings

public static boolean isPalindrome(String str){
    return isPalindrome(str,0,str.length()-1);
}

public static boolean isPalindrome(String str, int start, int end){
    if(start >= end)
        return true;
    else
        return (str.charAt(start) == str.charAt(end)) && isPalindrome(str, start+1, end-1);
}

How to render an ASP.NET MVC view as a string?

I found a new solution that renders a view to string without having to mess with the Response stream of the current HttpContext (which doesn't allow you to change the response's ContentType or other headers).

Basically, all you do is create a fake HttpContext for the view to render itself:

/// <summary>Renders a view to string.</summary>
public static string RenderViewToString(this Controller controller,
                                        string viewName, object viewData) {
    //Create memory writer
    var sb = new StringBuilder();
    var memWriter = new StringWriter(sb);

    //Create fake http context to render the view
    var fakeResponse = new HttpResponse(memWriter);
    var fakeContext = new HttpContext(HttpContext.Current.Request, fakeResponse);
    var fakeControllerContext = new ControllerContext(
        new HttpContextWrapper(fakeContext),
        controller.ControllerContext.RouteData,
        controller.ControllerContext.Controller);

    var oldContext = HttpContext.Current;
    HttpContext.Current = fakeContext;

    //Use HtmlHelper to render partial view to fake context
    var html = new HtmlHelper(new ViewContext(fakeControllerContext,
        new FakeView(), new ViewDataDictionary(), new TempDataDictionary()),
        new ViewPage());
    html.RenderPartial(viewName, viewData);

    //Restore context
    HttpContext.Current = oldContext;    

    //Flush memory and return output
    memWriter.Flush();
    return sb.ToString();
}

/// <summary>Fake IView implementation used to instantiate an HtmlHelper.</summary>
public class FakeView : IView {
    #region IView Members

    public void Render(ViewContext viewContext, System.IO.TextWriter writer) {
        throw new NotImplementedException();
    }

    #endregion
}

This works on ASP.NET MVC 1.0, together with ContentResult, JsonResult, etc. (changing Headers on the original HttpResponse doesn't throw the "Server cannot set content type after HTTP headers have been sent" exception).

Update: in ASP.NET MVC 2.0 RC, the code changes a bit because we have to pass in the StringWriter used to write the view into the ViewContext:

//...

//Use HtmlHelper to render partial view to fake context
var html = new HtmlHelper(
    new ViewContext(fakeControllerContext, new FakeView(),
        new ViewDataDictionary(), new TempDataDictionary(), memWriter),
    new ViewPage());
html.RenderPartial(viewName, viewData);

//...

How to check if element has any children in Javascript?

<script type="text/javascript">

function uwtPBSTree_NodeChecked(treeId, nodeId, bChecked) 
{
    //debugger;
    var selectedNode = igtree_getNodeById(nodeId);
    var ParentNodes = selectedNode.getChildNodes();

    var length = ParentNodes.length;

    if (bChecked) 
    {
/*                if (length != 0) {
                    for (i = 0; i < length; i++) {
                        ParentNodes[i].setChecked(true);
                    }
    }*/
    }
    else 
    {
        if (length != 0) 
        {
            for (i = 0; i < length; i++) 
            {
                ParentNodes[i].setChecked(false);
            }
        }
    }
}
</script>

<ignav:UltraWebTree ID="uwtPBSTree" runat="server"..........>
<ClientSideEvents NodeChecked="uwtPBSTree_NodeChecked"></ClientSideEvents>
</ignav:UltraWebTree>

Setting the default Java character encoding

Try this :

    new OutputStreamWriter( new FileOutputStream("Your_file_fullpath" ),Charset.forName("UTF8"))

How to have Java method return generic list of any type?

You can use the old way:

public List magicalListGetter() {
    List list = doMagicalVooDooHere();

    return list;
}

or you can use Object and the parent class of everything:

public List<Object> magicalListGetter() {
    List<Object> list = doMagicalVooDooHere();

    return list;
}

Note Perhaps there is a better parent class for all the objects you will put in the list. For example, Number would allow you to put Double and Integer in there.

How can I remove or replace SVG content?

Here is the solution:

d3.select("svg").remove();

This is a remove function provided by D3.js.

What is the (best) way to manage permissions for Docker shared volumes?

Here's an approach that still uses a data-only container but doesn't require it to be synced with the application container (in terms of having the same uid/gid).

Presumably, you want to run some app in the container as a non-root $USER without a login shell.

In the Dockerfile:

RUN useradd -s /bin/false myuser

# Set environment variables
ENV VOLUME_ROOT /data
ENV USER myuser

...

ENTRYPOINT ["./entrypoint.sh"]

Then, in entrypoint.sh:

chown -R $USER:$USER $VOLUME_ROOT
su -s /bin/bash - $USER -c "cd $repo/build; $@"

Simplest/cleanest way to implement a singleton in JavaScript

function Unicode()
{
  var i = 0, unicode = {}, zero_padding = "0000", max = 9999;

  // Loop through code points
  while (i < max) {
    // Convert decimal to hex value, find the character,
    // and then pad zeroes to the code point
    unicode[String.fromCharCode(parseInt(i, 16))] = ("u" + zero_padding + i).substr(-4);
    i = i + 1;
  }

  // Replace this function with the resulting lookup table
  Unicode = unicode;
}

// Usage
Unicode();

// Lookup
Unicode["%"]; // Returns 0025

Get current NSDate in timestamp format

use [[NSDate date] timeIntervalSince1970]

Create an Android GPS tracking application

The source code for the Android mobile application open-gpstracker which you appreciated is available here.

You can checkout the code using SVN client application or via Git:

Debugging the source code will surely help you.

How can I check whether a numpy array is empty or not?

You can always take a look at the .size attribute. It is defined as an integer, and is zero (0) when there are no elements in the array:

import numpy as np
a = np.array([])

if a.size == 0:
    # Do something when `a` is empty

Execute Shell Script after post build in Jenkins

You can also run arbitrary commands using the Groovy Post Build - and that will give you a lot of control over when they run and so forth. We use that to run a 'finger of blame' shell script in the case of failed or unstable builds.

if (manager.build.result.isWorseThan(hudson.model.Result.SUCCESS)) {
  item = hudson.model.Hudson.instance.getItem("PROJECTNAMEHERE")
  lastStableBuild = item.getLastStableBuild()
  lastStableDate = lastStableBuild.getTime()
  formattedLastStableDate = lastStableDate.format("MM/dd/yyyy h:mm:ss a")
  now = new Date()
  formattedNow = now.format("MM/dd/yyyy h:mm:ss a")
  command = ['/appframe/jenkins/appframework/fob.ksh', "${formattedLastStableDate}", "${formattedNow}"]
  manager.listener.logger.println "FOB Command: ${command}"
  manager.listener.logger.println command.execute().text
}

(Our command takes the last stable build date and the current time as parameters so it can go investigate who might have broken the build, but you could run whatever commands you like in a similar fashion)

Switch statement fallthrough in C#?

You can 'goto case label' http://www.blackwasp.co.uk/CSharpGoto.aspx

The goto statement is a simple command that unconditionally transfers the control of the program to another statement. The command is often criticised with some developers advocating its removal from all high-level programming languages because it can lead to spaghetti code. This occurs when there are so many goto statements or similar jump statements that the code becomes difficult to read and maintain. However, there are programmers who point out that the goto statement, when used carefully, provides an elegant solution to some problems...

JavaScript: Upload file

Pure JS

You can use fetch optionally with await-try-catch

let photo = document.getElementById("image-file").files[0];
let formData = new FormData();
     
formData.append("photo", photo);
fetch('/upload/image', {method: "POST", body: formData});

_x000D_
_x000D_
async function SavePhoto(inp) 
{
    let user = { name:'john', age:34 };
    let formData = new FormData();
    let photo = inp.files[0];      
         
    formData.append("photo", photo);
    formData.append("user", JSON.stringify(user)); 
    
    const ctrl = new AbortController()    // timeout
    setTimeout(() => ctrl.abort(), 5000);
    
    try {
       let r = await fetch('/upload/image', 
         {method: "POST", body: formData, signal: ctrl.signal}); 
       console.log('HTTP response code:',r.status); 
    } catch(e) {
       console.log('Huston we have problem...:', e);
    }
    
}
_x000D_
<input id="image-file" type="file" onchange="SavePhoto(this)" >
<br><br>
Before selecting the file open chrome console > network tab to see the request details.
<br><br>
<small>Because in this example we send request to https://stacksnippets.net/upload/image the response code will be 404 ofcourse...</small>

<br><br>
(in stack overflow snippets there is problem with error handling, however in <a href="https://jsfiddle.net/Lamik/b8ed5x3y/5/">jsfiddle version</a> for 404 errors 4xx/5xx are <a href="https://stackoverflow.com/a/33355142/860099">not throwing</a> at all but we can read response status which contains code)
_x000D_
_x000D_
_x000D_

Old school approach - xhr

let photo = document.getElementById("image-file").files[0];  // file from input
let req = new XMLHttpRequest();
let formData = new FormData();

formData.append("photo", photo);                                
req.open("POST", '/upload/image');
req.send(formData);

_x000D_
_x000D_
function SavePhoto(e) 
{
    let user = { name:'john', age:34 };
    let xhr = new XMLHttpRequest();
    let formData = new FormData();
    let photo = e.files[0];      
    
    formData.append("user", JSON.stringify(user));   
    formData.append("photo", photo);
    
    xhr.onreadystatechange = state => { console.log(xhr.status); } // err handling
    xhr.timeout = 5000;
    xhr.open("POST", '/upload/image'); 
    xhr.send(formData);
}
_x000D_
<input id="image-file" type="file" onchange="SavePhoto(this)" >
<br><br>
Choose file and open chrome console > network tab to see the request details.
<br><br>
<small>Because in this example we send request to https://stacksnippets.net/upload/image the response code will be 404 ofcourse...</small>

<br><br>
(the stack overflow snippets, has some problem with error handling - the xhr.status is zero (instead of 404) which is similar to situation when we run script from file on <a href="https://stackoverflow.com/a/10173639/860099">local disc</a> - so I provide also js fiddle version which shows proper http error code <a href="https://jsfiddle.net/Lamik/k6jtq3uh/2/">here</a>)
_x000D_
_x000D_
_x000D_

SUMMARY

  • In server side you can read original file name (and other info) which is automatically included to request by browser in filename formData parameter.
  • You do NOT need to set request header Content-Type to multipart/form-data - this will be set automatically by browser.
  • Instead of /upload/image you can use full address like http://.../upload/image.
  • If you want to send many files in single request use multiple attribute: <input multiple type=... />, and attach all chosen files to formData in similar way (e.g. photo2=...files[2];... formData.append("photo2", photo2);)
  • You can include additional data (json) to request e.g. let user = {name:'john', age:34} in this way: formData.append("user", JSON.stringify(user));
  • You can set timeout: for fetch using AbortController, for old approach by xhr.timeout= milisec
  • This solutions should work on all major browsers.

How to check whether a string contains a substring in Ruby

You can use the include? method:

my_string = "abcdefg"
if my_string.include? "cde"
   puts "String includes 'cde'"
end

chrome undo the action of "prevent this page from creating additional dialogs"

So the correct answer is: YES, there is a better way.

Right click on the tab and select "Duplicate", then close the original tab if you wish.

Alerting is re-enabled in the duplicate.

The duplicate tab seems to recreate the running state of the original tab so you can just continue where you were.

Run Jquery function on window events: load, resize, and scroll?

You can bind listeners to one common functions -

$(window).bind("load resize scroll",function(e){
  // do stuff
});

Or another way -

$(window).bind({
     load:function(){

     },
     resize:function(){

     },
     scroll:function(){

    }
});

Alternatively, instead of using .bind() you can use .on() as bind directly maps to on(). And maybe .bind() won't be there in future jquery versions.

$(window).on({
     load:function(){

     },
     resize:function(){

     },
     scroll:function(){

    }
});

Java Array Sort descending?

Another solution is that if you're making use of the Comparable interface you can switch the output values which you had specified in your compareTo(Object bCompared).

For Example :

public int compareTo(freq arg0) 
{
    int ret=0;
    if(this.magnitude>arg0.magnitude)
        ret= 1;
    else if (this.magnitude==arg0.magnitude)
        ret= 0;
    else if (this.magnitude<arg0.magnitude)
        ret= -1;
    return ret;
}

Where magnitude is an attribute with datatype double in my program. This was sorting my defined class freq in reverse order by it's magnitude. So in order to correct that, you switch the values returned by the < and >. This gives you the following :

public int compareTo(freq arg0) 
{
    int ret=0;
    if(this.magnitude>arg0.magnitude)
        ret= -1;
    else if (this.magnitude==arg0.magnitude)
        ret= 0;
    else if (this.magnitude<arg0.magnitude)
        ret= 1;
    return ret;
}

To make use of this compareTo, we simply call Arrays.sort(mFreq) which will give you the sorted array freq [] mFreq.

The beauty (in my opinion) of this solution is that it can be used to sort user defined classes, and even more than that sort them by a specific attribute. If implementation of a Comparable interface sounds daunting to you, I'd encourage you not to think that way, it actually isn't. This link on how to implement comparable made things much easier for me. Hoping persons can make use of this solution, and that your joy will even be comparable to mine.

SQL permissions for roles

SQL-Server follows the principle of "Least Privilege" -- you must (explicitly) grant permissions.

'does it mean that they wont be able to update 4 and 5 ?'

If your users in the doctor role are only in the doctor role, then yes.

However, if those users are also in other roles (namely, other roles that do have access to 4 & 5), then no.

More Information: http://msdn.microsoft.com/en-us/library/bb669084%28v=vs.110%29.aspx

Rails 3: I want to list all paths defined in my rails application

Trying http://0.0.0.0:3000/routes on a Rails 5 API app (i.e.: JSON-only oriented) will (as of Rails beta 3) return

{"status":404,"error":"Not Found","exception":"#> 
<ActionController::RoutingError:...

However, http://0.0.0.0:3000/rails/info/routes will render a nice, simple HTML page with routes.

How do you force Visual Studio to regenerate the .designer files for aspx/ascx files?

I've found a way to solve this problem without changing any code or running commands like "Convert to Web Application" - and it's simple too!

What I found was that restarting Visual Studio often solves the problem, but sometimes it doesn't. In those cases, if you close Visual Studio and then delete all content in the "obj" directory for the web project before you open it again, it has always worked for me.

(when started again you just add a space and remove it again and then hit save to have the designer file properly regenerated)

Maximum request length exceeded.

maxRequestLength (length in KB) Here as ex. I took 1024 (1MB) maxAllowedContentLength (length in Bytes) should be same as your maxRequestLength (1048576 bytes = 1MB).

<system.web>
   <httpRuntime maxRequestLength="1024" executionTimeout="3600" />
</system.web>

<system.webServer>
   <security>
      <requestFiltering>
          <requestLimits maxAllowedContentLength="1048576"/>
      </requestFiltering>
   </security>
</system.webServer>

Tool to compare directories (Windows 7)

The tool that richardtz suggests is excellent.

Another one that is amazing and comes with a 30 day free trial is Araxis Merge. This one does a 3 way merge and is much more feature complete than winmerge, but it is a commercial product.

You might also like to check out Scott Hanselman's developer tool list, which mentions a couple more in addition to winmerge

SELECT * FROM in MySQLi

This was already a month ago, but oh well.

I could be wrong, but for your question I get the feeling that bind_param isn't really the problem here. You always need to define some conditions, be it directly in the query string itself, of using bind_param to set the ? placeholders. That's not really an issue.

The problem I had using MySQLi SELECT * queries is the bind_result part. That's where it gets interesting. I came across this post from Jeffrey Way: http://jeff-way.com/2009/05/27/tricky-prepared-statements/(This link is no longer active). The script basically loops through the results and returns them as an array — no need to know how many columns there are, and you can still use prepared statements.

In this case it would look something like this:

$stmt = $mysqli->prepare(
  'SELECT * FROM tablename WHERE field1 = ? AND field2 = ?');
$stmt->bind_param('ss', $value, $value2);
$stmt->execute();

Then use the snippet from the site:

$meta = $stmt->result_metadata();

while ($field = $meta->fetch_field()) {
  $parameters[] = &$row[$field->name];
}

call_user_func_array(array($stmt, 'bind_result'), $parameters);

while ($stmt->fetch()) {
  foreach($row as $key => $val) {
    $x[$key] = $val;
  }
  $results[] = $x;
}

And $results now contains all the info from SELECT *. So far I found this to be an ideal solution.

Codeigniter displays a blank page instead of error messages

This behavior occurs when you have basic php syntax error in your code. In case when you have syntax errors the php parser does not parse the code completely and didnot display anything so all of the above suggestion would work only if you have other than syntax errors.

How do I import a Swift file from another Swift file?

So, you need to

  1. Import external modules you want to use
  2. And make sure you have the right access modifiers on the class and methods you want to use.

In my case I had a swift file I wanted to unit test, and the unit test file was also a swift class. I made sure the access modifiers were correct, but the statement

import stMobile

(let's say that stMobile is our target name)

still did not work (I was still getting the 'No such module' error), I checked my target, and its name was indeed stMobile. So, I went to Build Settings, under packaging, and found the Product Module Name, and for some reason this was called St_Mobile, so I changed my import statement

import St_Mobile

(which is the Product Module Name), and everything worked.

So, to sum up:

  1. Check your Product Module Name and use the import statement below in you unit test class

    import myProductModuleName
    
  2. Make sure your access modifiers are correct (class level and your methods).

curl POST format for CURLOPT_POSTFIELDS

For CURLOPT_POSTFIELDS, the parameters can either be passed as a urlencoded string like para1=val1&para2=val2&.. or as an array with the field name as key and field data as value

Try the following format :

$data = json_encode(array(
"first"  => "John",
"last" => "Smith"
));

$ch = curl_init(); 
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
$output = curl_exec($ch);
curl_close($ch);

How to check if IEnumerable is null or empty?

I had the same problem and I solve it like :

    public bool HasMember(IEnumerable<TEntity> Dataset)
    {
        return Dataset != null && Dataset.Any(c=>c!=null);
    }

"c=>c!=null" will ignore all the null entities.

C++ Redefinition Header Files (winsock2.h)

In VS 2015, the following will work:

#define _WINSOCKAPI_

While the following won't:

#define WIN32_LEAN_AND_MEAN

How can I auto increment the C# assembly version via our CI platform (Hudson)?

My solution doesn't require the addition of external tools or scripting languages --it's pretty much guaranteed to work on your build machine. I solve this problem in several parts. First, I have created a BUILD.BAT file that converts the Jenkins BUILD_NUMBER parameter into an environment variable. I use Jenkins's "Execute Windows batch command" function to run the build batch file by entering the following information for the Jenkins build:

     ./build.bat --build_id %BUILD_ID% -build_number %BUILD_NUMBER%

In the build environment, I have a build.bat file that starts as follows:

     rem build.bat
     set BUILD_ID=Unknown
     set BUILD_NUMBER=0
     :parse_command_line
     IF NOT "%1"=="" (
         IF "%1"=="-build_id" (
             SET BUILD_ID=%2
             SHIFT
             )
         IF "%1"=="-build_number" (
             SET BUILD_NUMBER=%2
             SHIFT
         )
         SHIFT
         GOTO :parse_command_line
     )
     REM your build continues with the environmental variables set
     MSBUILD.EXE YourProject.sln

Once I did that, I right-clicked on the project to be built in Visual Studio's Solution Explorer pane and selected Properties, select Build Events, and entered the following information as the Pre-Build Event Command Line, which automatically creates a .cs file containing build number information based on current environment variable settings:

     set VERSION_FILE=$(ProjectDir)\Properties\VersionInfo.cs
     if !%BUILD_NUMBER%==! goto no_buildnumber_set
     goto buildnumber_set
     :no_buildnumber_set
     set BUILD_NUMBER=0
     :buildnumber_set
     if not exist %VERSION_FILE% goto no_version_file
     del /q %VERSION_FILE%
     :no_version_file
     echo using System.Reflection; >> %VERSION_FILE%
     echo using System.Runtime.CompilerServices; >> %VERSION_FILE%
     echo using System.Runtime.InteropServices; >> %VERSION_FILE%
     echo [assembly: AssemblyVersion("0.0.%BUILD_NUMBER%.1")] >> %VERSION_FILE%
     echo [assembly: AssemblyFileVersion("0.0.%BUILD_NUMBER%.1")] >> %VERSION_FILE%

You may need to adjust to your build taste. I build the project manually once to generate an initial Version.cs file in the Properties directory of the main project. Lastly, I manually include the Version.cs file into the Visual Studio solution by dragging it into the Solution Explorer pane, underneath the Properties tab for that project. In future builds, Visual Studio then reads that .cs file at Jenkins build time and gets the correct build number information out of it.

Check if all checkboxes are selected

$('input.abc').not(':checked').length > 0

Use <Image> with a local file

To display image from local folder, you need to write down code:

 <Image source={require('../assets/self.png')}/>

Here I have put my image in asset folder.

starting file download with JavaScript

I suggest to make an invisible iframe on the page and set it's src to url that you've received from the server - download will start without page reloading.

Or you can just set the current document.location.href to received url address. But that's can cause for user to see an error if the requested document actually does not exists.

Check if a variable is between two numbers with Java

are you writing java code for android? in that case you should write maybe

if (90 >= angle && angle <= 180) {

updating the code to a nicer style (like some suggested) you would get:

if (angle <= 90 && angle <= 180) {

now you see that the second check is unnecessary or maybe you mixed up < and > signs in the first check and wanted actually to have

if (angle >= 90 && angle <= 180) {

C: convert double to float, preserving decimal point precision

Floating point numbers are represented in scientific notation as a number of only seven significant digits multiplied by a larger number that represents the place of the decimal place. More information about it on Wikipedia:

http://en.wikipedia.org/wiki/Floating_point

Plotting a 2D heatmap with Matplotlib

Seaborn takes care of a lot of the manual work and automatically plots a gradient at the side of the chart etc.

import numpy as np
import seaborn as sns
import matplotlib.pylab as plt

uniform_data = np.random.rand(10, 12)
ax = sns.heatmap(uniform_data, linewidth=0.5)
plt.show()

enter image description here

Or, you can even plot upper / lower left / right triangles of square matrices, for example a correlation matrix which is square and is symmetric, so plotting all values would be redundant anyway.

corr = np.corrcoef(np.random.randn(10, 200))
mask = np.zeros_like(corr)
mask[np.triu_indices_from(mask)] = True
with sns.axes_style("white"):
    ax = sns.heatmap(corr, mask=mask, vmax=.3, square=True,  cmap="YlGnBu")
    plt.show()

enter image description here

Android textview outline text

So, little late, but MagicTextView will do text outlines, amongst other things.

enter image description here

<com.qwerjk.better_text.MagicTextView
    xmlns:qwerjk="http://schemas.android.com/apk/res/com.qwerjk.better_text"
    android:textSize="78dp"
    android:textColor="#ff333333"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    qwerjk:strokeColor="#FFff0000"
    qwerjk:strokeJoinStyle="miter"
    qwerjk:strokeWidth="5"
    android:text="Magic" />

Note: I made this, and am posting more for the sake of future travelers than the OP. It's borderline spam, but being on-topic, perhaps acceptable?

Checking whether a String contains a number value in Java

Another possible solution is to use a Scanner object like this:

Scanner scanner = new Scanner(inputString);  
if (scanner.hasNextInt()) {  
  return true;
}
else {
  return false
}

Of course, if you are looking for a double, use hasNextDouble() method (see: Scanner javadoc)

Running the new Intel emulator for Android

Using SDK Manager to download Intel HAX did not work.

Downloading and installing it from the Intel website did work. http://software.intel.com/en-us/articles/intel-hardware-accelerated-execution-manager/

Top Tip: making the change in my BIOS to enable virtualization and then using "restart" did not enable virtualization. Doing a cold boot (i.e. shutdown and restart) suddenly made it appear.

The first step (on Windows) is to make sure that the Micrsoft Hardware-Assisted Virtualization Tool reports that "this computer is configured with hardware-assisted virtualization". http://www.microsoft.com/en-us/download/details.aspx?id=592

How to trigger HTML button when you press Enter in textbox?

Do not use Javascript for this!

Modern HTML pages automatically allow a form's submit button to submit the page with the ENTER/RETURN key when any form field control in the web page has focus by the user, autofocus attribute is set on a form field or button, or user tab's into any of the form fields.

So instead of Javascripting this, an easier solution is to add tabindex=0 on your form fields and button inside a form element then autofocus on the first input control. The user can then press "ENTER" to submit the form at any point as they enter data:

<form id="buttonform2" name="buttonform2" action="#" method="get" role="form">
  <label for="username1">Username</label>
  <input type="text" id="username1" name="username" value="" size="20" maxlength="20" title="Username" tabindex="0" autofocus="autofocus" />
  <label for="password1">Password</label>
  <input type="password" id="password1" name="password" size="20" maxlength="20" value="" title="Password" tabindex="0" role="textbox" aria-label="Password" />
  <button id="button2" name="button2" type="submit" value="submit" form="buttonform2" title="Submit" tabindex="0" role="button" aria-label="Submit">Submit</button>
</form>

Compare string with all values in list

for word in d:
    if d in paid[j]:
         do_something()

will try all the words in the list d and check if they can be found in the string paid[j].

This is not very efficient since paid[j] has to be scanned again for each word in d. You could also use two sets, one composed of the words in the sentence, one of your list, and then look at the intersection of the sets.

sentence = "words don't come easy"
d = ["come", "together", "easy", "does", "it"]

s1 = set(sentence.split())
s2 = set(d)

print (s1.intersection(s2))

Output:

{'come', 'easy'}

Change color of bootstrap navbar on hover link?

You would have to overwrite the CSS rule:

.navbar-inverse .brand, .navbar-inverse .nav > li > a

or

.navbar .brand, .navbar .nav > li > a 

depending if you are using the dark or light theme, respectively. To do this, add a CSS with your overwritten rules and make sure it comes in your HTML after the Bootstrap CSS. For example:

.navbar .brand, .navbar .nav > li > a {
    color: #D64848;
}
.navbar .brand, .navbar .nav > li > a:hover {
    color: #F56E6E;
}

There is also the alternative where you customize your own Boostrap here. In this case, in the Navbar section, you have the @navbarLinkColor.

Adding days to $Date in PHP

Here is a small snippet to demonstrate the date modifications:

$date = date("Y-m-d");
//increment 2 days
$mod_date = strtotime($date."+ 2 days");
echo date("Y-m-d",$mod_date) . "\n";

//decrement 2 days
$mod_date = strtotime($date."- 2 days");
echo date("Y-m-d",$mod_date) . "\n";

//increment 1 month
$mod_date = strtotime($date."+ 1 months");
echo date("Y-m-d",$mod_date) . "\n";

//increment 1 year
$mod_date = strtotime($date."+ 1 years");
echo date("Y-m-d",$mod_date) . "\n";

Defining TypeScript callback type

I came across the same error when trying to add the callback to an event listener. Strangely, setting the callback type to EventListener solved it. It looks more elegant than defining a whole function signature as a type, but I'm not sure if this is the correct way to do this.

class driving {
    // the answer from this post - this works
    // private callback: () => void; 

    // this also works!
    private callback:EventListener;

    constructor(){
        this.callback = () => this.startJump();
        window.addEventListener("keydown", this.callback);
    }

    startJump():void {
        console.log("jump!");
        window.removeEventListener("keydown", this.callback);
    }
}

difference between primary key and unique key

A primary key’s main features are:

It must contain a unique value for each row of data. It cannot contain null values. Only one Primary key in a table.

A Unique key’s main features are:

It can also contain a unique value for each row of data.

It can also contain null values.

Multiple Unique keys in a table.

How we can bold only the name in table td tag not the value

Try this

_x000D_
_x000D_
.Bold { font-weight: bold; }
_x000D_
<span> normal text</span> <br>_x000D_
<span class="Bold"> bold text</span> <br>_x000D_
<span> normal text</span> <spanspan>
_x000D_
_x000D_
_x000D_

Wait until all promises complete even if some rejected

I really like Benjamin's answer, and how he basically turns all promises into always-resolving-but-sometimes-with-error-as-a-result ones. :)
Here's my attempt at your request just in case you were looking for alternatives. This method simply treats errors as valid results, and is coded similar to Promise.all otherwise:

Promise.settle = function(promises) {
  var results = [];
  var done = promises.length;

  return new Promise(function(resolve) {
    function tryResolve(i, v) {
      results[i] = v;
      done = done - 1;
      if (done == 0)
        resolve(results);
    }

    for (var i=0; i<promises.length; i++)
      promises[i].then(tryResolve.bind(null, i), tryResolve.bind(null, i));
    if (done == 0)
      resolve(results);
  });
}

Graphviz: How to go from .dot to a graph?

type: dot -Tps filename.dot -o outfile.ps

If you want to use the dot renderer. There are alternatives like neato and twopi. If graphiz isn't in your path, figure out where it is installed and run it from there.

You can change the output format by varying the value after -T and choosing an appropriate filename extension after -o.

If you're using windows, check out the installed tool called GVEdit, it makes the whole process slightly easier.

Go look at the graphviz site in the section called "User's Guides" for more detail on how to use the tools:

http://www.graphviz.org/documentation/

(See page 27 for output formatting for the dot command, for instance)

http://www.graphviz.org/pdf/dotguide.pdf

Valid characters in a Java class name

Class names should be nouns in UpperCamelCase, with the first letter of every word capitalised. Use whole words — avoid acronyms and abbreviations (unless the abbreviation is much more widely used than the long form, such as URL or HTML). The naming conventions can be read over here:

http://www.oracle.com/technetwork/java/codeconventions-135099.html

Is there a way to provide named parameters in a function call in JavaScript?

Trying Node-6.4.0 ( process.versions.v8 = '5.0.71.60') and Node Chakracore-v7.0.0-pre8 and then Chrome-52 (V8=5.2.361.49), I've noticed that named parameters are almost implemented, but that order has still precedence. I can't find what the ECMA standard says.

>function f(a=1, b=2){ console.log(`a=${a} + b=${b} = ${a+b}`) }

> f()
a=1 + b=2 = 3
> f(a=5)
a=5 + b=2 = 7
> f(a=7, b=10)
a=7 + b=10 = 17

But order is required!! Is it the standard behaviour?

> f(b=10)
a=10 + b=2 = 12

In WPF, what are the differences between the x:Name and Name attributes?

x:Name and Name are referencing different namespaces.

x:name is a reference to the x namespace defined by default at the top of the Xaml file.

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

Just saying Name uses the default below namespace.

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

x:Name is saying use the namespace that has the x alias. x is the default and most people leave it but you can change it to whatever you like

xmlns:foo="http://schemas.microsoft.com/winfx/2006/xaml"

so your reference would be foo:name

Define and Use Namespaces in WPF


OK lets look at this a different way. Say you drag and drop an button onto your Xaml page. You can reference this 2 ways x:name and name. All xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" and xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" are is references to multiple namespaces. Since xaml holds the Control namespace(not 100% on that) and presentation holds the FrameworkElement AND the Button class has a inheritance pattern of:

Button : ButtonBase
ButtonBase : ContentControl, ICommandSource
ContentControl : Control, IAddChild
Control : FrameworkElement
FrameworkElement : UIElement, IFrameworkInputElement, 
                    IInputElement, ISupportInitialize, IHaveResources

So as one would expect anything that inherits from FrameworkElement would have access to all its public attributes. so in the case of Button it is getting its Name attribute from FrameworkElement, at the very top of the hierarchy tree. So you can say x:Name or Name and they will both be accessing the getter/setter from the FrameworkElement.

MSDN Reference

WPF defines a CLR attribute that is consumed by XAML processors in order to map multiple CLR namespaces to a single XML namespace. The XmlnsDefinitionAttribute attribute is placed at the assembly level in the source code that produces the assembly. The WPF assembly source code uses this attribute to map the various common namespaces, such as System.Windows and System.Windows.Controls, to the http://schemas.microsoft.com/winfx/2006/xaml/presentation namespace.

So the assembly attributes will look something like:

PresentationFramework.dll - XmlnsDefinitionAttribute:

[assembly: XmlnsDefinition("http://schemas.microsoft.com/winfx/2006/xaml/presentation", "System.Windows")]

[assembly: XmlnsDefinition("http://schemas.microsoft.com/winfx/2006/xaml/presentation", "System.Windows.Data")]

[assembly: XmlnsDefinition("http://schemas.microsoft.com/winfx/2006/xaml/presentation", "System.Windows.Navigation")]

[assembly: XmlnsDefinition("http://schemas.microsoft.com/winfx/2006/xaml/presentation", "System.Windows.Shapes")]

[assembly: XmlnsDefinition("http://schemas.microsoft.com/winfx/2006/xaml/presentation", "System.Windows.Documents")]

[assembly: XmlnsDefinition("http://schemas.microsoft.com/winfx/2006/xaml/presentation", "System.Windows.Controls")]  

How can I list the scheduled jobs running in my database?

The DBA views are restricted. So you won't be able to query them unless you're connected as a DBA or similarly privileged user.

The ALL views show you the information you're allowed to see. Normally that would be jobs you've submitted, unless you have additional privileges.

The privileges you need are defined in the Admin Guide. Find out more.

So, either you need a DBA account or you need to chat with your DBA team about getting access to the information you need.

Reading Excel file using node.js

There are a few different libraries doing parsing of Excel files (.xlsx). I will list two projects I find interesting and worth looking into.

Node-xlsx

Excel parser and builder. It's kind of a wrapper for a popular project JS-XLSX, which is a pure javascript implementation from the Office Open XML spec.

node-xlsx project page

Example for parsing file

var xlsx = require('node-xlsx');

var obj = xlsx.parse(__dirname + '/myFile.xlsx'); // parses a file

var obj = xlsx.parse(fs.readFileSync(__dirname + '/myFile.xlsx')); // parses a buffer

ExcelJS

Read, manipulate and write spreadsheet data and styles to XLSX and JSON. It's an active project. At the time of writing the latest commit was 9 hours ago. I haven't tested this myself, but the api looks extensive with a lot of possibilites.

exceljs project page

Code example:

// read from a file
var workbook = new Excel.Workbook();
workbook.xlsx.readFile(filename)
    .then(function() {
        // use workbook
    });

// pipe from stream
var workbook = new Excel.Workbook();
stream.pipe(workbook.xlsx.createInputStream());

How to filter Pandas dataframe using 'in' and 'not in' like in SQL

Collating possible solutions from the answers:

For IN: df[df['A'].isin([3, 6])]

For NOT IN:

  1. df[-df["A"].isin([3, 6])]

  2. df[~df["A"].isin([3, 6])]

  3. df[df["A"].isin([3, 6]) == False]

  4. df[np.logical_not(df["A"].isin([3, 6]))]

Find all elements with a certain attribute value in jquery

$('div[imageId="imageN"]').each(function() {
    // `this` is the div
});

To check for the sole existence of the attribute, no matter which value, you could use ths selector instead: $('div[imageId]')

Call a Vue.js component method from outside the component

This is a simple way to access a component's methods from other component

// This is external shared (reusable) component, so you can call its methods from other components

export default {
   name: 'SharedBase',
   methods: {
      fetchLocalData: function(module, page){
          // .....fetches some data
          return { jsonData }
      }
   }
}

// This is your component where you can call SharedBased component's method(s)
import SharedBase from '[your path to component]';
var sections = [];

export default {
   name: 'History',
   created: function(){
       this.sections = SharedBase.methods['fetchLocalData']('intro', 'history');
   }
}

Select distinct values from a list using LINQ in C#

Try,

var newList = 
(
from x in empCollection
select new {Loc = x.empLoc, PL = x.empPL, Shift = x.empShift}
).Distinct();

Finding an item in a List<> using C#

item = objects.Find(obj => obj.property==myValue);

How can I determine the character encoding of an excel file?

For Excel 2010 it should be UTF-8. Instruction by MS :
http://msdn.microsoft.com/en-us/library/bb507946:

"The basic document structure of a SpreadsheetML document consists of the Sheets and Sheet elements, which reference the worksheets in the Workbook. A separate XML file is created for each Worksheet. For example, the SpreadsheetML for a workbook that has two worksheets name MySheet1 and MySheet2 is located in the Workbook.xml file and is shown in the following code example.

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?> 
<workbook xmlns=http://schemas.openxmlformats.org/spreadsheetml/2006/main xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
    <sheets>
        <sheet name="MySheet1" sheetId="1" r:id="rId1" /> 
        <sheet name="MySheet2" sheetId="2" r:id="rId2" /> 
    </sheets>
</workbook>

The worksheet XML files contain one or more block level elements such as SheetData. sheetData represents the cell table and contains one or more Row elements. A row contains one or more Cell elements. Each cell contains a CellValue element that represents the value of the cell. For example, the SpreadsheetML for the first worksheet in a workbook, that only has the value 100 in cell A1, is located in the Sheet1.xml file and is shown in the following code example.

<?xml version="1.0" encoding="UTF-8" ?> 
<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
    <sheetData>
        <row r="1">
            <c r="A1">
                <v>100</v> 
            </c>
        </row>
    </sheetData>
</worksheet>

"

Detection of cell encodings:

https://metacpan.org/pod/Spreadsheet::ParseExcel::Cell

http://forums.asp.net/t/1608228.aspx/1

Installing R with Homebrew

If you run

xcode-select --install

you do you not need to install gcc through brew, and you will not have to waste time compiling gcc. See https://stackoverflow.com/a/24967219/2668545 for more details.

After that, you can simply do

brew tap homebrew/science
brew install Caskroom/cask/xquartz
brew install r

Understanding Apache's access log

I also don't under stand what the "-" means after the 200 140 section of the log

That value corresponds to the referer as described by Joachim. If you see a dash though, that means that there was no referer value to begin with (eg. the user went straight to a specific destination, like if he/she typed a URL in their browser)

Indent multiple lines quickly in vi

As well as the offered solutions, I like to do things a paragraph at a time with >}

Regular expression include and exclude special characters

[a-zA-Z0-9~@#\^\$&\*\(\)-_\+=\[\]\{\}\|\\,\.\?\s]*

This would do the matching, if you only want to allow that just wrap it in ^$ or any other delimiters that you see appropriate, if you do this no specific disallow logic is needed.

How to select bottom most rows?

try this.

declare @floor int --this is the offset from the bottom, the number of results to exclude
declare @resultLimit int --the number of results actually retrieved for use
declare @total int --just adds them up, the total number of results fetched initially

--following is for gathering top 60 results total, then getting rid of top 50. We only keep the last 10
set @floor = 50 
set @resultLimit = 10
set @total = @floor + @resultLimit

declare @tmp0 table(
    --table body
)

declare @tmp1 table(
    --table body
)

--this line will drop the wanted results from whatever table we're selecting from
insert into @tmp0
select Top @total --what to select (the where, from, etc)

--using floor, insert the part we don't want into the second tmp table
insert into @tmp1
select top @floor * from @tmp0

--using select except, exclude top x results from the query
select * from @tmp0
except 
select * from @tmp1

__FILE__, __LINE__, and __FUNCTION__ usage in C++

In rare cases, it can be useful to change the line that is given by __LINE__ to something else. I've seen GNU configure does that for some tests to report appropriate line numbers after it inserted some voodoo between lines that do not appear in original source files. For example:

#line 100

Will make the following lines start with __LINE__ 100. You can optionally add a new file-name

#line 100 "file.c"

It's only rarely useful. But if it is needed, there are no alternatives I know of. Actually, instead of the line, a macro can be used too which must result in any of the above two forms. Using the boost preprocessor library, you can increment the current line by 50:

#line BOOST_PP_ADD(__LINE__, 50)

I thought it's useful to mention it since you asked about the usage of __LINE__ and __FILE__. One never gets enough surprises out of C++ :)

Edit: @Jonathan Leffler provides some more good use-cases in the comments:

Messing with #line is very useful for pre-processors that want to keep errors reported in the user's C code in line with the user's source file. Yacc, Lex, and (more at home to me) ESQL/C preprocessors do that.

Images can't contain alpha channels or transparencies

Extending Roman B. answer. This is still a problem, I was uploading a cordova app. my solution using mogrify:

brew install imagemagick
* navigate to `platforms/ios/<your_app_name>/Images.xcassets/AppIcon.appiconset`*
mogrify -alpha off *.png

Then archived and validated successfully.

running multiple bash commands with subprocess

I just stumbled on a situation where I needed to run a bunch of lines of bash code (not separated with semicolons) from within python. In this scenario the proposed solutions do not help. One approach would be to save a file and then run it with Popen, but it wasn't possible in my situation.

What I ended up doing is something like:

commands = '''
echo "a"
echo "b"
echo "c"
echo "d"
'''

process = subprocess.Popen('/bin/bash', stdin=subprocess.PIPE, stdout=subprocess.PIPE)
out, err = process.communicate(commands)
print out

So I first create the child bash process and after I tell it what to execute. This approach removes the limitations of passing the command directly to the Popen constructor.

How do I rotate a picture in WinForms

This solution assumes that you want to draw the image in a picture box and that the image orientation will follow the mouse movements over this picture box. No image is assigned to the picture box. Instead I'm getting the image from a project resource.

private float _angle;

public Form1()
{
    InitializeComponent();
}

private void PictureBox_MouseMove(object sender, MouseEventArgs e)
{
    (float centerX, float centerY) = GetCenter(pictureBox1.ClientRectangle);
    _angle = (float)(Math.Atan2(e.Y - centerY, e.X - centerX) * 180.0 / Math.PI);
    pictureBox1.Invalidate(); // Triggers redrawing
}

private void PictureBox_Paint(object sender, PaintEventArgs e)
{
    Bitmap image = Properties.Resources.ExampleImage;
    float scale = (float)pictureBox1.Width / image.Width;

    (float centerX, float centerY) = GetCenter(e.ClipRectangle);

    e.Graphics.TranslateTransform(centerX, centerY);
    e.Graphics.RotateTransform(_angle);
    e.Graphics.TranslateTransform(-centerX, -centerY);
    e.Graphics.ScaleTransform(scale, scale);
    e.Graphics.DrawImage(image, 0, 0);
}

// Uses C# 7.0 value tuples / .NET Framework 4.7.
// For previous versions, return a PointF instead.
private static (float, float) GetCenter(Rectangle rect)
{
    float centerX = (rect.Left + rect.Right) * 0.5f;
    float centerY = (rect.Top + rect.Bottom) * 0.5f;
    return (centerX, centerY);
}

Make sure to to select the mouse event handlers PictureBox_MouseMove and PictureBox_Paint in properties window of the picture box for these events, after you copy/pasted this code into the form.

Note: You could also use a simple Panel or any other control, like a label; however, the PictureBox has the advantage to use double buffering by default, which eliminates flickering.

What is the difference between Serializable and Externalizable in Java?

Serialization uses certain default behaviors to store and later recreate the object. You may specify in what order or how to handle references and complex data structures, but eventually it comes down to using the default behavior for each primitive data field.

Externalization is used in the rare cases that you really want to store and rebuild your object in a completely different way and without using the default serialization mechanisms for data fields. For example, imagine that you had your own unique encoding and compression scheme.

JSON Stringify changes time of date because of UTC

Here is another answer (and personally I think it's more appropriate)

var currentDate = new Date(); 
currentDate = JSON.stringify(currentDate);

// Now currentDate is in a different format... oh gosh what do we do...

currentDate = new Date(JSON.parse(currentDate));

// Now currentDate is back to its original form :)

Convert javascript object or array to json for ajax data

You can use JSON.stringify(object) with an object and I just wrote a function that'll recursively convert an array to an object, like this JSON.stringify(convArrToObj(array)), which is the following code (more detail can be found on this answer):

// Convert array to object
var convArrToObj = function(array){
    var thisEleObj = new Object();
    if(typeof array == "object"){
        for(var i in array){
            var thisEle = convArrToObj(array[i]);
            thisEleObj[i] = thisEle;
        }
    }else {
        thisEleObj = array;
    }
    return thisEleObj;
}

To make it more generic, you can override the JSON.stringify function and you won't have to worry about it again, to do this, just paste this at the top of your page:

// Modify JSON.stringify to allow recursive and single-level arrays
(function(){
    // Convert array to object
    var convArrToObj = function(array){
        var thisEleObj = new Object();
        if(typeof array == "object"){
            for(var i in array){
                var thisEle = convArrToObj(array[i]);
                thisEleObj[i] = thisEle;
            }
        }else {
            thisEleObj = array;
        }
        return thisEleObj;
    };
    var oldJSONStringify = JSON.stringify;
    JSON.stringify = function(input){
        return oldJSONStringify(convArrToObj(input));
    };
})();

And now JSON.stringify will accept arrays or objects! (link to jsFiddle with example)


Edit:

Here's another version that's a tad bit more efficient, although it may or may not be less reliable (not sure -- it depends on if JSON.stringify(array) always returns [], which I don't see much reason why it wouldn't, so this function should be better as it does a little less work when you use JSON.stringify with an object):

(function(){
    // Convert array to object
    var convArrToObj = function(array){
        var thisEleObj = new Object();
        if(typeof array == "object"){
            for(var i in array){
                var thisEle = convArrToObj(array[i]);
                thisEleObj[i] = thisEle;
            }
        }else {
            thisEleObj = array;
        }
        return thisEleObj;
    };
    var oldJSONStringify = JSON.stringify;
    JSON.stringify = function(input){
        if(oldJSONStringify(input) == '[]')
            return oldJSONStringify(convArrToObj(input));
        else
            return oldJSONStringify(input);
    };
})();

jsFiddle with example here

js Performance test here, via jsPerf

How do I install g++ for Fedora?

The package you're looking for is confusingly named gcc-c++.

MySql difference between two timestamps in days?

SELECT DATEDIFF( now(), '2013-06-20' );

here datediff takes two arguments 'upto-date', 'from-date'

What i have done is, using now() function, i can get no. of days since 20-june-2013 till today.

Removing Conda environment

Official documentation way worked for me:

conda remove --name myenv --all

Or just conda env remove --name myenv.

To verify that the environment was removed, in your terminal window or an Anaconda Prompt, run:

conda info --envs

The environments list that displays should not show the removed environment.

You anaconda3 enviroments folder might list an empty folder of deleted environment in your anaconda3 installation folder, like:

/opt/anaconda3/envs

Why does ASP.NET webforms need the Runat="Server" attribute?

I think that Microsoft can fix this ambiguity by making the compiler add runat attribute before the page is ever compiled, something like the type-erasure thing that java has with the generics, instead of erasing, it could be writing runat=server wherever it sees asp: prefix for tags, so the developer would not need to worry about it.

How to validate date with format "mm/dd/yyyy" in JavaScript?

First string date is converted to js date format and converted into string format again, then it is compared with original string.

function dateValidation(){
    var dateString = "34/05/2019"
    var dateParts = dateString.split("/");
    var date= new Date(+dateParts[2], dateParts[1] - 1, +dateParts[0]);

    var isValid = isValid( dateString, date );
    console.log("Is valid date: " + isValid);
}

function isValidDate(dateString, date) {
    var newDateString = ( date.getDate()<10 ? ('0'+date.getDate()) : date.getDate() )+ '/'+ ((date.getMonth() + 1)<10? ('0'+(date.getMonth() + 1)) : (date.getMonth() + 1) )  + '/' +  date.getFullYear();
    return ( dateString == newDateString);
}

How to fix error ::Format of the initialization string does not conform to specification starting at index 0::

I originally was calling the connection string value as shown below (VB.NET) and got the error being mentioned

 Using connection As New SqlConnection("connectionStringName") 
  '// more code would go here...
 End Using

adding a reference to System.Configuration and updating my code as shown below was my solution. The connection string was not the problem since others controls used it without any issues (SqlDataSource)

Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("connectionStringName").ConnectionString)
    '// more code would go here...
End Using

How to create a directory using Ansible

I see lots of Playbooks examples and I would like to mention the Adhoc commands example.

$ansible -i inventory -m file -a "path=/tmp/direcory state=directory ( instead of directory we can mention touch to create files)

Difference between Interceptor and Filter in Spring MVC

From HandlerIntercepter's javadoc:

HandlerInterceptor is basically similar to a Servlet Filter, but in contrast to the latter it just allows custom pre-processing with the option of prohibiting the execution of the handler itself, and custom post-processing. Filters are more powerful, for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured in web.xml, a HandlerInterceptor in the application context.

As a basic guideline, fine-grained handler-related pre-processing tasks are candidates for HandlerInterceptor implementations, especially factored-out common handler code and authorization checks. On the other hand, a Filter is well-suited for request content and view content handling, like multipart forms and GZIP compression. This typically shows when one needs to map the filter to certain content types (e.g. images), or to all requests.

With that being said:

So where is the difference between Interceptor#postHandle() and Filter#doFilter()?

postHandle will be called after handler method invocation but before the view being rendered. So, you can add more model objects to the view but you can not change the HttpServletResponse since it's already committed.

doFilter is much more versatile than the postHandle. You can change the request or response and pass it to the chain or even block the request processing.

Also, in preHandle and postHandle methods, you have access to the HandlerMethod that processed the request. So, you can add pre/post-processing logic based on the handler itself. For example, you can add a logic for handler methods that have some annotations.

What is the best practise in which use cases it should be used?

As the doc said, fine-grained handler-related pre-processing tasks are candidates for HandlerInterceptor implementations, especially factored-out common handler code and authorization checks. On the other hand, a Filter is well-suited for request content and view content handling, like multipart forms and GZIP compression. This typically shows when one needs to map the filter to certain content types (e.g. images), or to all requests.

Grep for beginning and end of line?

It should be noted that not only will the caret (^) behave differently within the brackets, it will have the opposite result of placing it outside of the brackets. Placing the caret where you have it will search for all strings NOT beginning with the content you placed within the brackets. You also would want to place a period before the asterisk in between your brackets as with grep, it also acts as a "wildcard".

grep ^[.rwx].*[0-9]$

This should work for you, I noticed that some posters used a character class in their expressions which is an effective method as well, but you were not using any in your original expression so I am trying to get one as close to yours as possible explaining every minor change along the way so that it is better understood. How can we learn otherwise?

Generate Json schema from XML schema (XSD)

Disclaimer: I am the author of Jsonix, a powerful open-source XML<->JSON JavaScript mapping library.

Today I've released the new version of the Jsonix Schema Compiler, with the new JSON Schema generation feature.

Let's take the Purchase Order schema for example. Here's a fragment:

  <xsd:element name="purchaseOrder" type="PurchaseOrderType"/>

  <xsd:complexType name="PurchaseOrderType">
    <xsd:sequence>
      <xsd:element name="shipTo" type="USAddress"/>
      <xsd:element name="billTo" type="USAddress"/>
      <xsd:element ref="comment" minOccurs="0"/>
      <xsd:element name="items"  type="Items"/>
    </xsd:sequence>
    <xsd:attribute name="orderDate" type="xsd:date"/>
  </xsd:complexType>

You can compile this schema using the provided command-line tool:

java -jar jsonix-schema-compiler-full.jar
    -generateJsonSchema
    -p PO
    schemas/purchaseorder.xsd

The compiler generates Jsonix mappings as well the matching JSON Schema.

Here's what the result looks like (edited for brevity):

{
    "id":"PurchaseOrder.jsonschema#",
    "definitions":{
        "PurchaseOrderType":{
            "type":"object",
            "title":"PurchaseOrderType",
            "properties":{
                "shipTo":{
                    "title":"shipTo",
                    "allOf":[
                        {
                            "$ref":"#/definitions/USAddress"
                        }
                    ]
                },
                "billTo":{
                    "title":"billTo",
                    "allOf":[
                        {
                            "$ref":"#/definitions/USAddress"
                        }
                    ]
                }, ...
            }
        },
        "USAddress":{ ... }, ...
    },
    "anyOf":[
        {
            "type":"object",
            "properties":{
                "name":{
                    "$ref":"http://www.jsonix.org/jsonschemas/w3c/2001/XMLSchema.jsonschema#/definitions/QName"
                },
                "value":{
                    "$ref":"#/definitions/PurchaseOrderType"
                }
            },
            "elementName":{
                "localPart":"purchaseOrder",
                "namespaceURI":""
            }
        }
    ]
}

Now this JSON Schema is derived from the original XML Schema. It is not exactly 1:1 transformation, but very very close.

The generated JSON Schema matches the generatd Jsonix mappings. So if you use Jsonix for XML<->JSON conversion, you should be able to validate JSON with the generated JSON Schema. It also contains all the required metadata from the originating XML Schema (like element, attribute and type names).

Disclaimer: At the moment this is a new and experimental feature. There are certain known limitations and missing functionality. But I'm expecting this to manifest and mature very fast.

Links:

Finding whether a point lies inside a rectangle or not

How is the rectangle represented? Three points? Four points? Point, sides and angle? Two points and a side? Something else? Without knowing that, any attempts to answer your question will have only purely academic value.

In any case, for any convex polygon (including rectangle) the test is very simple: check each edge of the polygon, assuming each edge is oriented in counterclockwise direction, and test whether the point lies to the left of the edge (in the left-hand half-plane). If all edges pass the test - the point is inside. If at least one fails - the point is outside.

In order to test whether the point (xp, yp) lies on the left-hand side of the edge (x1, y1) - (x2, y2), you just need to calculate

D = (x2 - x1) * (yp - y1) - (xp - x1) * (y2 - y1)

If D > 0, the point is on the left-hand side. If D < 0, the point is on the right-hand side. If D = 0, the point is on the line.


The previous version of this answer described a seemingly different version of left-hand side test (see below). But it can be easily shown that it calculates the same value.

... In order to test whether the point (xp, yp) lies on the left-hand side of the edge (x1, y1) - (x2, y2), you need to build the line equation for the line containing the edge. The equation is as follows

A * x + B * y + C = 0

where

A = -(y2 - y1)
B = x2 - x1
C = -(A * x1 + B * y1)

Now all you need to do is to calculate

D = A * xp + B * yp + C

If D > 0, the point is on the left-hand side. If D < 0, the point is on the right-hand side. If D = 0, the point is on the line.

However, this test, again, works for any convex polygon, meaning that it might be too generic for a rectangle. A rectangle might allow a simpler test... For example, in a rectangle (or in any other parallelogram) the values of A and B have the same magnitude but different signs for opposing (i.e. parallel) edges, which can be exploited to simplify the test.

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

For me the command:

set PATH=%PATH%;C:\Python34\Scripts

worked immediately (try after echo %PATH% and you will see that your path has the value C:\Python34\Scripts).

Thanks to: Adding a directory to the PATH environment variable in Windows

Using find command in bash script

If you want to loop over what you "find", you should use this:

find . -type f -name '*.*' -print0 | while IFS= read -r -d '' file; do
    printf '%s\n' "$file"
done

Source: https://askubuntu.com/questions/343727/filenames-with-spaces-breaking-for-loop-find-command

Single huge .css file vs. multiple smaller specific .css files?

This is a hard one to answer. Both options have their pros and cons in my opinion.

I personally don't love reading through a single HUGE CSS file, and maintaining it is very difficult. On the other hand, splitting it out causes extra http requests which could potentially slow things down.

My opinion would be one of two things.

1) If you know that your CSS will NEVER change once you've built it, I'd build multiple CSS files in the development stage (for readability), and then manually combine them before going live (to reduce http requests)

2) If you know that you're going to change your CSS once in a while, and need to keep it readable, I would build separate files and use code (providing you're using some sort of programming language) to combine them at runtime build time (runtime minification/combination is a resource pig).

With either option I would highly recommend caching on the client side in order to further reduce http requests.

EDIT:
I found this blog that shows how to combine CSS at runtime using nothing but code. Worth taking a look at (though I haven't tested it myself yet).

EDIT 2:
I've settled on using separate files in my design time, and a build process to minify and combine. This way I can have separate (manageable) css while I develop and a proper monolithic minified file at runtime. And I still have my static files and less system overhead because I'm not doing compression/minification at runtime.

note: for you shoppers out there, I highly suggest using bundler as part of your build process. Whether you're building from within your IDE, or from a build script, bundler can be executed on Windows via the included exe or can be run on any machine that is already running node.js.

Facebook Graph API, how to get users email?

Just add these code block on status return, and start passing a query string object {}. For JavaScript devs

After initializing your sdk.

step 1: // get login status

$(document).ready(function($) {
    FB.getLoginStatus(function(response) {
        statusChangeCallback(response);
        console.log(response);
    });
  });

This will check on document load and get your login status check if users has been logged in.

Then the function checkLoginState is called, and response is pass to statusChangeCallback

function checkLoginState() {
    FB.getLoginStatus(function(response) {
      statusChangeCallback(response);
    });
  }

Step 2: Let you get the response data from the status

function statusChangeCallback(response) {
    // body...
    if(response.status === 'connected'){
      // setElements(true);
      let userId = response.authResponse.userID;
      // console.log(userId);
      console.log('login');
      getUserInfo(userId);

    }else{
      // setElements(false);
      console.log('not logged in !');
    }
  }

This also has the userid which is being set to variable, then a getUserInfo func is called to fetch user information using the Graph-api.

function getUserInfo(userId) {
    // body...
    FB.api(
      '/'+userId+'/?fields=id,name,email',
      'GET',
      {},
      function(response) {
        // Insert your code here
        // console.log(response);
        let email = response.email;
        loginViaEmail(email);
      }
    );
  }

After passing the userid as an argument, the function then fetch all information relating to that userid. Note: in my case i was looking for the email, as to allowed me run a function that can logged user via email only.

// login via email

function loginViaEmail(email) {
    // body...
    let token = '{{ csrf_token() }}';

    let data = {
      _token:token,
      email:email
    }

    $.ajax({
      url: '/login/via/email',    
      type: 'POST',
      dataType: 'json',
      data: data,
      success: function(data){
        console.log(data);
        if(data.status == 'success'){
          window.location.href = '/dashboard';
        }

        if(data.status == 'info'){
          window.location.href = '/create-account'; 
        }
      },
      error: function(data){
        console.log('Error logging in via email !');
        // alert('Fail to send login request !');
      }
    });
  }

What does functools.wraps do?

As of python 3.5+:

@functools.wraps(f)
def g():
    pass

Is an alias for g = functools.update_wrapper(g, f). It does exactly three things:

  • it copies the __module__, __name__, __qualname__, __doc__, and __annotations__ attributes of f on g. This default list is in WRAPPER_ASSIGNMENTS, you can see it in the functools source.
  • it updates the __dict__ of g with all elements from f.__dict__. (see WRAPPER_UPDATES in the source)
  • it sets a new __wrapped__=f attribute on g

The consequence is that g appears as having the same name, docstring, module name, and signature than f. The only problem is that concerning the signature this is not actually true: it is just that inspect.signature follows wrapper chains by default. You can check it by using inspect.signature(g, follow_wrapped=False) as explained in the doc. This has annoying consequences:

  • the wrapper code will execute even when the provided arguments are invalid.
  • the wrapper code can not easily access an argument using its name, from the received *args, **kwargs. Indeed one would have to handle all cases (positional, keyword, default) and therefore to use something like Signature.bind().

Now there is a bit of confusion between functools.wraps and decorators, because a very frequent use case for developing decorators is to wrap functions. But both are completely independent concepts. If you're interested in understanding the difference, I implemented helper libraries for both: decopatch to write decorators easily, and makefun to provide a signature-preserving replacement for @wraps. Note that makefun relies on the same proven trick than the famous decorator library.

Remove 'b' character do in front of a string literal in Python 3

Here u Go

f = open('test.txt','rb+')
ch=f.read(1)
ch=str(ch,'utf-8')
print(ch)

How can I replace non-printable Unicode characters in Java?

I propose it remove the non printable characters like below instead of replacing it

private String removeNonBMPCharacters(final String input) {
    StringBuilder strBuilder = new StringBuilder();
    input.codePoints().forEach((i) -> {
        if (Character.isSupplementaryCodePoint(i)) {
            strBuilder.append("?");
        } else {
            strBuilder.append(Character.toChars(i));
        }
    });
    return strBuilder.toString();
}

How to use the divide function in the query?

Try something like this

select Cast((SPGI09_EARLY_OVER_T – (SPGI09_OVER_WK_EARLY_ADJUST_T) / (SPGI09_EARLY_OVER_T + SPGR99_LATE_CM_T  + SPGR99_ON_TIME_Q)) as varchar(20) + '%' as percentageAmount
from CSPGI09_OVERSHIPMENT

I presume the value is a representation in percentage - if not convert it to a valid percentage total, then add the % sign and convert the column to varchar.

How to install XCODE in windows 7 platform?

X-code is primarily made for OS-X or iPhone development on Mac systems. Versions for Windows are not available. However this might help!

There is no way to get Xcode on Windows; however you can use a different SDK like Corona instead although it will not use Objective-C (I believe it uses Lua). I have however heard that it is horrible to use.

Source: classroomm.com

How to read a text file into a list or an array with Python

This question is asking how to read the comma-separated value contents from a file into an iterable list:

0,0,200,0,53,1,0,255,...,0.

The easiest way to do this is with the csv module as follows:

import csv
with open('filename.dat', newline='') as csvfile:
    spamreader = csv.reader(csvfile, delimiter=',')

Now, you can easily iterate over spamreader like this:

for row in spamreader:
    print(', '.join(row))

See documentation for more examples.

How to add checkboxes to JTABLE swing

1) JTable knows JCheckbox with built-in Boolean TableCellRenderers and TableCellEditor by default, then there is contraproductive declare something about that,

2) AbstractTableModel should be useful, where is in the JTable required to reduce/restrict/change nested and inherits methods by default implemented in the DefaultTableModel,

3) consider using DefaultTableModel, (if you are not sure about how to works) instead of AbstractTableModel,

table_with_BooleanType_column

could be generated from simple code:

import javax.swing.*;
import javax.swing.table.*;

public class TableCheckBox extends JFrame {

    private static final long serialVersionUID = 1L;
    private JTable table;

    public TableCheckBox() {
        Object[] columnNames = {"Type", "Company", "Shares", "Price", "Boolean"};
        Object[][] data = {
            {"Buy", "IBM", new Integer(1000), new Double(80.50), false},
            {"Sell", "MicroSoft", new Integer(2000), new Double(6.25), true},
            {"Sell", "Apple", new Integer(3000), new Double(7.35), true},
            {"Buy", "Nortel", new Integer(4000), new Double(20.00), false}
        };
        DefaultTableModel model = new DefaultTableModel(data, columnNames);
        table = new JTable(model) {

            private static final long serialVersionUID = 1L;

            /*@Override
            public Class getColumnClass(int column) {
            return getValueAt(0, column).getClass();
            }*/
            @Override
            public Class getColumnClass(int column) {
                switch (column) {
                    case 0:
                        return String.class;
                    case 1:
                        return String.class;
                    case 2:
                        return Integer.class;
                    case 3:
                        return Double.class;
                    default:
                        return Boolean.class;
                }
            }
        };
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JScrollPane scrollPane = new JScrollPane(table);
        getContentPane().add(scrollPane);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                TableCheckBox frame = new TableCheckBox();
                frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocation(150, 150);
                frame.setVisible(true);
            }
        });
    }
}

How do I install a JRE or JDK to run the Android Developer Tools on Windows 7?

download jre1.7.0_45 and then extract it into the Eclipse folder and rename folder of jre1.7.0_45 to jre and Eclipse will run

What does "restore purchases" in In-App purchases mean?

You typically restore purchases with this code:

[[SKPaymentQueue defaultQueue] restoreCompletedTransactions];

It will reinvoke -paymentQueue:updatedTransactions on the observer(s) for the purchased items. This is useful for users who reinstall the app after deletion or install it on a different device.

Not all types of In-App purchases can be restored.

Ansible: create a user with sudo privileges

To create a user with sudo privileges is to put the user into /etc/sudoers, or make the user a member of a group specified in /etc/sudoers. And to make it password-less is to additionally specify NOPASSWD in /etc/sudoers.

Example of /etc/sudoers:

## Allow root to run any commands anywhere
root    ALL=(ALL)       ALL

## Allows people in group wheel to run all commands
%wheel  ALL=(ALL)       ALL

## Same thing without a password
%wheel  ALL=(ALL)       NOPASSWD: ALL

And instead of fiddling with /etc/sudoers file, we can create a new file in /etc/sudoers.d/ directory since this directory is included by /etc/sudoers by default, which avoids the possibility of breaking existing sudoers file, and also eliminates the dependency on the content inside of /etc/sudoers.

To achieve above in Ansible, refer to the following:

- name: sudo without password for wheel group
  copy:
    content: '%wheel ALL=(ALL:ALL) NOPASSWD:ALL'
    dest: /etc/sudoers.d/wheel_nopasswd
    mode: 0440

You may replace %wheel with other group names like %sudoers or other user names like deployer.

Why do I get a "permission denied" error while installing a gem?

I had the same problem using rvm on Ubuntu, was fixed by setting the source on my terminal as a short-term solution:

source $HOME/.rvm/scripts/rvm

or

source /home/$USER/.rvm/scripts/rvm

and configure a default Ruby Version, 2.3.3 in my case.

rvm use 2.3.3 --default


And a long-term Solution is to add your source to your .bashrc file to permanently make Ubuntu look in .rvm for all the Ruby files.

Add:

source .rvm/scripts/rvm

into

$HOME/.bashrc file.

What does it mean to "call" a function in Python?

I'll give a slightly advanced answer. In Python, functions are first-class objects. This means they can be "dynamically created, destroyed, passed to a function, returned as a value, and have all the rights as other variables in the programming language have."

Calling a function/class instance in Python means invoking the __call__ method of that object. For old-style classes, class instances are also callable but only if the object which creates them has a __call__ method. The same applies for new-style classes, except there is no notion of "instance" with new-style classes. Rather they are "types" and "objects".

As quoted from the Python 2 Data Model page, for function objects, class instances(old style classes), and class objects(new-style classes), "x(arg1, arg2, ...) is a shorthand for x.__call__(arg1, arg2, ...)".

Thus whenever you define a function with the shorthand def funcname(parameters): you are really just creating an object with a method __call__ and the shorthand for __call__ is to just name the instance and follow it with parentheses containing the arguments to the call. Because functions are first class objects in Python, they can be created on the fly with dynamic parameters (and thus accept dynamic arguments). This comes into handy with decorator functions/classes which you will read about later.

For now I suggest reading the Official Python Tutorial.

Java - Access is denied java.io.FileNotFoundException

Not exactly the case of this question but can be helpful. I got this exception when i call mkdirs() on new file instead of its parent

File file = new java.io.File(path);
//file.mkdirs(); // wrong! 
file.getParentFile().mkdirs(); // correct!
if (!file.exists()) {
    file.createNewFile();
} 

Add a summary row with totals

You could use the ROLLUP operator

SELECT  CASE 
            WHEN (GROUPING([Type]) = 1) THEN 'Total'
            ELSE [Type] END AS [TYPE]
        ,SUM([Total Sales]) as Total_Sales
From    Before
GROUP BY
        [Type] WITH ROLLUP

Make a div fill up the remaining width

Although a bit late in posting an answer, here is an alternative approach without using margins.

<style>
    #divMain { width: 500px; }
    #div1 { width: 100px; float: left; background-color: #fcc; }
    #div2 { overflow:hidden; background-color: #cfc; }
    #div3 { width: 100px; float: right; background-color: #ccf; }
</style>

<div id="divMain">
    <div id="div1">
        div 1
    </div>
    <div id="div3">
        div 3
    </div>
    <div id="div2">
        div 2<br />bit taller
    </div>
</div>

This method works like magic, but here is an explanation :)\

Fiddle with a similar sample here.

How do you clear your Visual Studio cache on Windows Vista?

I experienced this today. The value in Config was the updated one but the application would return the older value, stop and starting the solution did nothing.

So I cleared the .Net Temp folder.

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files

It shouldn't create bugs but to be safe close your solution down first. Clear the Temporary ASP.NET Files then load up your solution.

My issue was sorted.

Print current call stack from a method in Python code

import traceback
traceback.print_stack()

Angular2 *ngIf check object array length in template

This article helped me alot figuring out why it wasn't working for me either. It give me a lesson to think of the webpage loading and how angular 2 interacts as a timeline and not just the point in time i'm thinking of. I didn't see anyone else mention this point, so I will...

The reason the *ngIf is needed because it will try to check the length of that variable before the rest of the OnInit stuff happens, and throw the "length undefined" error. So thats why you add the ? because it won't exist yet, but it will soon.

How do I use NSTimer?

NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:60 target:self selector:@selector(timerCalled) userInfo:nil repeats:NO];

-(void)timerCalled
{
     NSLog(@"Timer Called");
     // Your Code
}

Using Application context everywhere?

I like it, but I would suggest a singleton instead:

package com.mobidrone;

import android.app.Application;
import android.content.Context;

public class ApplicationContext extends Application
{
    private static ApplicationContext instance = null;

    private ApplicationContext()
    {
        instance = this;
    }

    public static Context getInstance()
    {
        if (null == instance)
        {
            instance = new ApplicationContext();
        }

        return instance;
    }
}

How can I find the maximum value and its index in array in MATLAB?

For a matrix you can use this:

[M,I] = max(A(:))

I is the index of A(:) containing the largest element.

Now, use the ind2sub function to extract the row and column indices of A corresponding to the largest element.

[I_row, I_col] = ind2sub(size(A),I)

source: https://www.mathworks.com/help/matlab/ref/max.html

Jquery Value match Regex

Change it to this:

var email = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i;

This is a regular expression literal that is passed the i flag which means to be case insensitive.

Keep in mind that email address validation is hard (there is a 4 or 5 page regular expression at the end of Mastering Regular Expressions demonstrating this) and your expression certainly will not capture all valid e-mail addresses.

How to check if a class inherits another class without instantiating it?

To check for assignability, you can use the Type.IsAssignableFrom method:

typeof(SomeType).IsAssignableFrom(typeof(Derived))

This will work as you expect for type-equality, inheritance-relationships and interface-implementations but not when you are looking for 'assignability' across explicit / implicit conversion operators.

To check for strict inheritance, you can use Type.IsSubclassOf:

typeof(Derived).IsSubclassOf(typeof(SomeType))

Set focus on <input> element

Only using Angular Template

<input type="text" #searchText>

<span (click)="searchText.focus()">clear</span>

Call PHP function from jQuery?

Thanks all. I took bits of each of your solutions and made my own.

The final working solution is:

<script type="text/javascript">
    $(document).ready(function(){
        $.ajax({
            url: '<?php bloginfo('template_url'); ?>/functions/twitter.php',
            data: "tweets=<?php echo $ct_tweets; ?>&account=<?php echo $ct_twitter; ?>",
            success: function(data) {
                $('#twitter-loader').remove();
                $('#twitter-container').html(data);
            }
        });
   });
</script>

Find Number of CPUs and Cores per CPU using Command Prompt

In order to check the absence of physical sockets run:

wmic cpu get SocketDesignation

How to access to a child method from the parent in vue.js

Ref and event bus both has issues when your control render is affected by v-if. So, I decided to go with a simpler method.

The idea is using an array as a queue to send methods that needs to be called to the child component. Once the component got mounted, it will process this queue. It watches the queue to execute new methods.

(Borrowing some code from Desmond Lua's answer)

Parent component code:

import ChildComponent from './components/ChildComponent'

new Vue({
  el: '#app',
  data: {
    item: {},
    childMethodsQueue: [],
  },
  template: `
  <div>
     <ChildComponent :item="item" :methods-queue="childMethodsQueue" />
     <button type="submit" @click.prevent="submit">Post</button>
  </div>
  `,
  methods: {
    submit() {
      this.childMethodsQueue.push({name: ChildComponent.methods.save.name, params: {}})
    }
  },
  components: { ChildComponent },
})

This is code for ChildComponent

<template>
 ...
</template>

<script>
export default {
  name: 'ChildComponent',
  props: {
    methodsQueue: { type: Array },
  },
  watch: {
    methodsQueue: function () {
      this.processMethodsQueue()
    },
  },
  mounted() {
    this.processMethodsQueue()
  },
  methods: {
    save() {
        console.log("Child saved...")
    },
    processMethodsQueue() {
      if (!this.methodsQueue) return
      let len = this.methodsQueue.length
      for (let i = 0; i < len; i++) {
        let method = this.methodsQueue.shift()
        this[method.name](method.params)
      }
    },
  },
}
</script>

And there is a lot of room for improvement like moving processMethodsQueue to a mixin...

Convert datetime to valid JavaScript date

This works everywhere including Safari 5 and Firefox 5 on OS X.

UPDATE: Fx Quantum (54) has no need for the replace, but Safari 11 is still not happy unless you convert as below

_x000D_
_x000D_
var date_test = new Date("2011-07-14 11:23:00".replace(/-/g,"/"));_x000D_
console.log(date_test);
_x000D_
_x000D_
_x000D_


FIDDLE

Get day of week using NSDate

SWIFT 2.0 code to present the current week starting from monday.

@IBAction func show(sender: AnyObject) {

   // Getting Days of week corresponding to their dateFormat

    let calendar = NSCalendar.currentCalendar()
    let dayInt: Int!
    var weekDate: [String] = []
    var i = 2

    print("Dates corresponding to days are")
    while((dayInt - dayInt) + i < 9)
    {
        let weekFirstDate = calendar.dateByAddingUnit(.Day, value: (-dayInt+i), toDate: NSDate(), options: [])
        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "EEEE dd MMMM"
        let dayOfWeekString = dateFormatter.stringFromDate(weekFirstDate!)
        weekDate.append(dayOfWeekString)
        i++
    }
    for i in weekDate
    {
        print(i) //Printing the day stored in array
    }
}

// function to get week day
func getDayOfWeek(today:String)->Int {

    let formatter  = NSDateFormatter()
    formatter.dateFormat = "MMM-dd-yyyy"
    let todayDate = formatter.dateFromString(today)!
    let myCalendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)!
    let myComponents = myCalendar.components(.Weekday, fromDate: todayDate)
    let weekDay = myComponents.weekday
    return weekDay
}


@IBAction func DateTitle(sender: AnyObject) {


    // Getting currentDate and weekDay corresponding to it
    let currentDate = NSDate()
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "MMM-dd-yyyy"
    let dayOfWeekStrings = dateFormatter.stringFromDate(currentDate)
    dayInt = getDayOfWeek(dayOfWeekStrings)

}

How to use a WSDL file to create a WCF service (not make a call)

You could use svcutil.exe to generate client code. This would include the definition of the service contract and any data contracts and fault contracts required.

Then, simply delete the client code: classes that implement the service contracts. You'll then need to implement them yourself, in your service.

ExecJS and could not find a JavaScript runtime

In your gem file Uncomment this line.

19 # gem 'therubyracer', platforms: :ruby

And run bundle install

You are ready to work. :)

Function return value in PowerShell

The existing answers are correct, but sometimes you aren't actually returning something explicitly with a Write-Output or a return, yet there is some mystery value in the function results. This could be the output of a builtin function like New-Item

PS C:\temp> function ContrivedFolderMakerFunction {
>>    $folderName = [DateTime]::Now.ToFileTime()
>>    $folderPath = Join-Path -Path . -ChildPath $folderName
>>    New-Item -Path $folderPath -ItemType Directory
>>    return $true
>> }
PS C:\temp> $result = ContrivedFolderMakerFunction
PS C:\temp> $result


    Directory: C:\temp


Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----         2/9/2020   4:32 PM                132257575335253136
True

All that extra noise of the directory creation is being collected and emitted in the output. The easy way to mitigate this is to add | Out-Null to the end of the New-Item statement, or you can assign the result to a variable and just not use that variable. It would look like this...

PS C:\temp> function ContrivedFolderMakerFunction {
>>    $folderName = [DateTime]::Now.ToFileTime()
>>    $folderPath = Join-Path -Path . -ChildPath $folderName
>>    New-Item -Path $folderPath -ItemType Directory | Out-Null
>>    # -or-
>>    $throwaway = New-Item -Path $folderPath -ItemType Directory 
>>    return $true
>> }
PS C:\temp> $result = ContrivedFolderMakerFunction
PS C:\temp> $result
True

New-Item is probably the more famous of these, but others include all of the StringBuilder.Append*() methods, as well as the SqlDataAdapter.Fill() method.

How to check if a file exists in a folder?

if (File.Exists(localUploadDirectory + "/" + fileName))
{                        
    `Your code here`
}

Emulate/Simulate iOS in Linux

On linux you can check epiphany-browser, resizes the windows you'll get same bugs as in ios. Both browsers uses Webkit.

Ubuntu/Mint:

sudo apt install epiphany-browser

How Spring Security Filter Chain works

The Spring security filter chain is a very complex and flexible engine.

Key filters in the chain are (in the order)

  • SecurityContextPersistenceFilter (restores Authentication from JSESSIONID)
  • UsernamePasswordAuthenticationFilter (performs authentication)
  • ExceptionTranslationFilter (catch security exceptions from FilterSecurityInterceptor)
  • FilterSecurityInterceptor (may throw authentication and authorization exceptions)

Looking at the current stable release 4.2.1 documentation, section 13.3 Filter Ordering you could see the whole filter chain's filter organization:

13.3 Filter Ordering

The order that filters are defined in the chain is very important. Irrespective of which filters you are actually using, the order should be as follows:

  1. ChannelProcessingFilter, because it might need to redirect to a different protocol

  2. SecurityContextPersistenceFilter, so a SecurityContext can be set up in the SecurityContextHolder at the beginning of a web request, and any changes to the SecurityContext can be copied to the HttpSession when the web request ends (ready for use with the next web request)

  3. ConcurrentSessionFilter, because it uses the SecurityContextHolder functionality and needs to update the SessionRegistry to reflect ongoing requests from the principal

  4. Authentication processing mechanisms - UsernamePasswordAuthenticationFilter, CasAuthenticationFilter, BasicAuthenticationFilter etc - so that the SecurityContextHolder can be modified to contain a valid Authentication request token

  5. The SecurityContextHolderAwareRequestFilter, if you are using it to install a Spring Security aware HttpServletRequestWrapper into your servlet container

  6. The JaasApiIntegrationFilter, if a JaasAuthenticationToken is in the SecurityContextHolder this will process the FilterChain as the Subject in the JaasAuthenticationToken

  7. RememberMeAuthenticationFilter, so that if no earlier authentication processing mechanism updated the SecurityContextHolder, and the request presents a cookie that enables remember-me services to take place, a suitable remembered Authentication object will be put there

  8. AnonymousAuthenticationFilter, so that if no earlier authentication processing mechanism updated the SecurityContextHolder, an anonymous Authentication object will be put there

  9. ExceptionTranslationFilter, to catch any Spring Security exceptions so that either an HTTP error response can be returned or an appropriate AuthenticationEntryPoint can be launched

  10. FilterSecurityInterceptor, to protect web URIs and raise exceptions when access is denied

Now, I'll try to go on by your questions one by one:

I'm confused how these filters are used. Is it that for the spring provided form-login, UsernamePasswordAuthenticationFilter is only used for /login, and latter filters are not? Does the form-login namespace element auto-configure these filters? Does every request (authenticated or not) reach FilterSecurityInterceptor for non-login url?

Once you are configuring a <security-http> section, for each one you must at least provide one authentication mechanism. This must be one of the filters which match group 4 in the 13.3 Filter Ordering section from the Spring Security documentation I've just referenced.

This is the minimum valid security:http element which can be configured:

<security:http authentication-manager-ref="mainAuthenticationManager" 
               entry-point-ref="serviceAccessDeniedHandler">
    <security:intercept-url pattern="/sectest/zone1/**" access="hasRole('ROLE_ADMIN')"/>
</security:http>

Just doing it, these filters are configured in the filter chain proxy:

{
        "1": "org.springframework.security.web.context.SecurityContextPersistenceFilter",
        "2": "org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter",
        "3": "org.springframework.security.web.header.HeaderWriterFilter",
        "4": "org.springframework.security.web.csrf.CsrfFilter",
        "5": "org.springframework.security.web.savedrequest.RequestCacheAwareFilter",
        "6": "org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter",
        "7": "org.springframework.security.web.authentication.AnonymousAuthenticationFilter",
        "8": "org.springframework.security.web.session.SessionManagementFilter",
        "9": "org.springframework.security.web.access.ExceptionTranslationFilter",
        "10": "org.springframework.security.web.access.intercept.FilterSecurityInterceptor"
    }

Note: I get them by creating a simple RestController which @Autowires the FilterChainProxy and returns it's contents:

    @Autowired
    private FilterChainProxy filterChainProxy;

    @Override
    @RequestMapping("/filterChain")
    public @ResponseBody Map<Integer, Map<Integer, String>> getSecurityFilterChainProxy(){
        return this.getSecurityFilterChainProxy();
    }

    public Map<Integer, Map<Integer, String>> getSecurityFilterChainProxy(){
        Map<Integer, Map<Integer, String>> filterChains= new HashMap<Integer, Map<Integer, String>>();
        int i = 1;
        for(SecurityFilterChain secfc :  this.filterChainProxy.getFilterChains()){
            //filters.put(i++, secfc.getClass().getName());
            Map<Integer, String> filters = new HashMap<Integer, String>();
            int j = 1;
            for(Filter filter : secfc.getFilters()){
                filters.put(j++, filter.getClass().getName());
            }
            filterChains.put(i++, filters);
        }
        return filterChains;
    }

Here we could see that just by declaring the <security:http> element with one minimum configuration, all the default filters are included, but none of them is of a Authentication type (4th group in 13.3 Filter Ordering section). So it actually means that just by declaring the security:http element, the SecurityContextPersistenceFilter, the ExceptionTranslationFilter and the FilterSecurityInterceptor are auto-configured.

In fact, one authentication processing mechanism should be configured, and even security namespace beans processing claims for that, throwing an error during startup, but it can be bypassed adding an entry-point-ref attribute in <http:security>

If I add a basic <form-login> to the configuration, this way:

<security:http authentication-manager-ref="mainAuthenticationManager">
    <security:intercept-url pattern="/sectest/zone1/**" access="hasRole('ROLE_ADMIN')"/>
    <security:form-login />
</security:http>

Now, the filterChain will be like this:

{
        "1": "org.springframework.security.web.context.SecurityContextPersistenceFilter",
        "2": "org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter",
        "3": "org.springframework.security.web.header.HeaderWriterFilter",
        "4": "org.springframework.security.web.csrf.CsrfFilter",
        "5": "org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter",
        "6": "org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter",
        "7": "org.springframework.security.web.savedrequest.RequestCacheAwareFilter",
        "8": "org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter",
        "9": "org.springframework.security.web.authentication.AnonymousAuthenticationFilter",
        "10": "org.springframework.security.web.session.SessionManagementFilter",
        "11": "org.springframework.security.web.access.ExceptionTranslationFilter",
        "12": "org.springframework.security.web.access.intercept.FilterSecurityInterceptor"
    }

Now, this two filters org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter and org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter are created and configured in the FilterChainProxy.

So, now, the questions:

Is it that for the spring provided form-login, UsernamePasswordAuthenticationFilter is only used for /login, and latter filters are not?

Yes, it is used to try to complete a login processing mechanism in case the request matches the UsernamePasswordAuthenticationFilter url. This url can be configured or even changed it's behaviour to match every request.

You could too have more than one Authentication processing mechanisms configured in the same FilterchainProxy (such as HttpBasic, CAS, etc).

Does the form-login namespace element auto-configure these filters?

No, the form-login element configures the UsernamePasswordAUthenticationFilter, and in case you don't provide a login-page url, it also configures the org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter, which ends in a simple autogenerated login page.

The other filters are auto-configured by default just by creating a <security:http> element with no security:"none" attribute.

Does every request (authenticated or not) reach FilterSecurityInterceptor for non-login url?

Every request should reach it, as it is the element which takes care of whether the request has the rights to reach the requested url. But some of the filters processed before might stop the filter chain processing just not calling FilterChain.doFilter(request, response);. For example, a CSRF filter might stop the filter chain processing if the request has not the csrf parameter.

What if I want to secure my REST API with JWT-token, which is retrieved from login? I must configure two namespace configuration http tags, rights? Other one for /login with UsernamePasswordAuthenticationFilter, and another one for REST url's, with custom JwtAuthenticationFilter.

No, you are not forced to do this way. You could declare both UsernamePasswordAuthenticationFilter and the JwtAuthenticationFilter in the same http element, but it depends on the concrete behaviour of each of this filters. Both approaches are possible, and which one to choose finnally depends on own preferences.

Does configuring two http elements create two springSecurityFitlerChains?

Yes, that's true

Is UsernamePasswordAuthenticationFilter turned off by default, until I declare form-login?

Yes, you could see it in the filters raised in each one of the configs I posted

How do I replace SecurityContextPersistenceFilter with one, which will obtain Authentication from existing JWT-token rather than JSESSIONID?

You could avoid SecurityContextPersistenceFilter, just configuring session strategy in <http:element>. Just configure like this:

<security:http create-session="stateless" >

Or, In this case you could overwrite it with another filter, this way inside the <security:http> element:

<security:http ...>  
   <security:custom-filter ref="myCustomFilter" position="SECURITY_CONTEXT_FILTER"/>    
</security:http>
<beans:bean id="myCustomFilter" class="com.xyz.myFilter" />

EDIT:

One question about "You could too have more than one Authentication processing mechanisms configured in the same FilterchainProxy". Will the latter overwrite the authentication performed by first one, if declaring multiple (Spring implementation) authentication filters? How this relates to having multiple authentication providers?

This finally depends on the implementation of each filter itself, but it's true the fact that the latter authentication filters at least are able to overwrite any prior authentication eventually made by preceding filters.

But this won't necesarily happen. I have some production cases in secured REST services where I use a kind of authorization token which can be provided both as a Http header or inside the request body. So I configure two filters which recover that token, in one case from the Http Header and the other from the request body of the own rest request. It's true the fact that if one http request provides that authentication token both as Http header and inside the request body, both filters will try to execute the authentication mechanism delegating it to the manager, but it could be easily avoided simply checking if the request is already authenticated just at the begining of the doFilter() method of each filter.

Having more than one authentication filter is related to having more than one authentication providers, but don't force it. In the case I exposed before, I have two authentication filter but I only have one authentication provider, as both of the filters create the same type of Authentication object so in both cases the authentication manager delegates it to the same provider.

And opposite to this, I too have a scenario where I publish just one UsernamePasswordAuthenticationFilter but the user credentials both can be contained in DB or LDAP, so I have two UsernamePasswordAuthenticationToken supporting providers, and the AuthenticationManager delegates any authentication attempt from the filter to the providers secuentially to validate the credentials.

So, I think it's clear that neither the amount of authentication filters determine the amount of authentication providers nor the amount of provider determine the amount of filters.

Also, documentation states SecurityContextPersistenceFilter is responsible of cleaning the SecurityContext, which is important due thread pooling. If I omit it or provide custom implementation, I have to implement the cleaning manually, right? Are there more similar gotcha's when customizing the chain?

I did not look carefully into this filter before, but after your last question I've been checking it's implementation, and as usually in Spring, nearly everything could be configured, extended or overwrited.

The SecurityContextPersistenceFilter delegates in a SecurityContextRepository implementation the search for the SecurityContext. By default, a HttpSessionSecurityContextRepository is used, but this could be changed using one of the constructors of the filter. So it may be better to write an SecurityContextRepository which fits your needs and just configure it in the SecurityContextPersistenceFilter, trusting in it's proved behaviour rather than start making all from scratch.

What's the syntax for mod in java

Here is the representation of your pseudo-code in minimal Java code;

boolean isEven = a % 2 == 0;

I'll now break it down into its components. The modulus operator in Java is the percent character (%). Therefore taking an int % int returns another int. The double equals (==) operator is used to compare values, such as a pair of ints and returns a boolean. This is then assigned to the boolean variable 'isEven'. Based on operator precedence the modulus will be evaluated before the comparison.

How do I multiply each element in a list by a number?

You can just use a list comprehension:

my_list = [1, 2, 3, 4, 5]
my_new_list = [i * 5 for i in my_list]

>>> print(my_new_list)
[5, 10, 15, 20, 25]

Note that a list comprehension is generally a more efficient way to do a for loop:

my_new_list = []
for i in my_list:
    my_new_list.append(i * 5)

>>> print(my_new_list)
[5, 10, 15, 20, 25]

As an alternative, here is a solution using the popular Pandas package:

import pandas as pd

s = pd.Series(my_list)

>>> s * 5
0     5
1    10
2    15
3    20
4    25
dtype: int64

Or, if you just want the list:

>>> (s * 5).tolist()
[5, 10, 15, 20, 25]

Best way to do Version Control for MS Excel

TortoiseSVN is an astonishingly good Windows client for the Subversion version control system. One feature which I just discovered that it has is that when you click to get a diff between versions of an Excel file, it will open both versions in Excel and highlight (in red) the cells that were changed. This is done through the magic of a vbs script, described here.

You may find this useful even if NOT using TortoiseSVN.

jQuery count number of divs with a certain class?

<!DOCTYPE html>
    <html>
    <head>
        <title></title>
        <style type="text/css">
            .test {
                background: #ff4040;
                color: #fff;
                display: block;
                font-size: 15px;
            }
        </style>
    </head>
    <body>
        <div class="test"> one </div>
        <div class="test"> two </div>
        <div class="test"> three </div>
        <div class="test"> four </div>
        <div class="test"> five </div>
        <div class="test"> six </div>
        <div class="test"> seven </div>
        <div class="test"> eight </div>
        <div class="test"> nine </div>
        <div class="test"> ten </div>
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
        <script type="text/javascript">
        $(document).ready(function () {
            //get total length by class
            var numItems = $('.test').length;
            //get last three count
            var numItems3=numItems-3;         


            var i = 0;
            $('.test').each(function(){
                i++;
                if(i>numItems3)
                {

                    $(this).attr("class","");
                }
            })
        });
    </script>
    </body>
    </html>

Generate preview image from Video file?

I recommend php-ffmpeg library.

Extracting image

You can extract a frame at any timecode using the FFMpeg\Media\Video::frame method.

This code returns a FFMpeg\Media\Frame instance corresponding to the second 42. You can pass any FFMpeg\Coordinate\TimeCode as argument, see dedicated documentation below for more information.

$frame = $video->frame(FFMpeg\Coordinate\TimeCode::fromSeconds(42));
$frame->save('image.jpg');

If you want to extract multiple images from the video, you can use the following filter:

$video
    ->filters()
    ->extractMultipleFrames(FFMpeg\Filters\Video\ExtractMultipleFramesFilter::FRAMERATE_EVERY_10SEC, '/path/to/destination/folder/')
    ->synchronize();

$video
    ->save(new FFMpeg\Format\Video\X264(), '/path/to/new/file');

By default, this will save the frames as jpg images.

You are able to override this using setFrameFileType to save the frames in another format:

$frameFileType = 'jpg'; // either 'jpg', 'jpeg' or 'png'
$filter = new ExtractMultipleFramesFilter($frameRate, $destinationFolder);
$filter->setFrameFileType($frameFileType);

$video->addFilter($filter);

Val and Var in Kotlin

Var means Variable-If you stored any object using 'var' it could change in time.

For example:

fun main(args: Array<String>) {
    var a=12
    var b=13
    var c=12
    a=c+b **//new object 25**
    print(a)
}

Val means value-It's like a 'constant' in java .if you stored any object using 'val' it could not change in time.

For Example:

fun main(args: Array<String>) {
    val a=12
    var b=13
    var c=12
    a=c+b **//You can't assign like that.it's an error.**
    print(a)
}

Why do Twitter Bootstrap tables always have 100% width?

I was having the same issue, I made the table fixed and then specified my td width. If you have th you can do those as well.

<style>
table {
table-layout: fixed;
word-wrap: break-word;
}
</style>

<td width="10%" /td>

I didn't have any luck with .table-nonfluid.

Display an image into windows forms

I display images in windows forms when I put it in Load event like this:

    private void Form1_Load( object sender , EventArgs e )
    {
        pictureBox1.ImageLocation = "./image.png"; //path to image
        pictureBox1.SizeMode = PictureBoxSizeMode.AutoSize;
    }

How to click a link whose href has a certain substring in Selenium?

use driver.findElement(By.partialLinkText("long")).click();

Column order manipulation using col-lg-push and col-lg-pull in Twitter Bootstrap 3

Pull "pulls" the div towards the left of the browser and and Push "pushes" the div away from left of browser.

Like: enter image description here

So basically in a 3 column layout of any web page the "Main Body" appears at the "Center" and in "Mobile" view the "Main Body" appears at the "Top" of the page. This is mostly desired by everyone with 3 column layout.

<div class="container">
    <div class="row">
        <div id="content" class="col-lg-4 col-lg-push-4 col-sm-12">
        <h2>This is Content</h2>
        <p>orem Ipsum ...</p>
        </div>

        <div id="sidebar-left" class="col-lg-4  col-sm-6 col-lg-pull-4">
        <h2>This is Left Sidebar</h2>
        <p>orem Ipsum...</p>
        </div>


        <div id="sidebar-right" class="col-lg-4 col-sm-6">
        <h2>This is Right Sidebar</h2>
        <p>orem Ipsum.... </p>
        </div>
    </div>
</div>

You can view it here: http://jsfiddle.net/DrGeneral/BxaNN/1/

Hope it helps

How does the getView() method work when creating your own custom adapter?

What is exactly the function of the LayoutInflater?

When you design using XML, all your UI elements are just tags and parameters. Before you can use these UI elements, (eg a TextView or LinearLayout), you need to create the actual objects corresponding to these xml elements. That is what the inflater is for. The inflater, uses these tags and their corresponding parameters to create the actual objects and set all the parameters. After this you can get a reference to the UI element using findViewById().

Why do all the articles that I've read check if convertview is null or not first? What does it mean when it is null and what does it mean when it isn't?

This is an interesting one. You see, getView() is called everytime an item in the list is drawn. Now, before the item can be drawn, it has to be created. Now convertView basically is the last used view to draw an item. In getView() you inflate the xml first and then use findByViewID() to get the various UI elements of the listitem. When we check for (convertView == null) what we do is check that if a view is null(for the first item) then create it, else, if it already exists, reuse it, no need to go through the inflate process again. Makes it a lot more efficient.

You must also have come across a concept of ViewHolder in getView(). This makes the list more efficient. What we do is create a viewholder and store the reference to all the UI elements that we got after inflating. This way, we can avoid calling the numerous findByViewId() and save on a lot of time. This ViewHolder is created in the (convertView == null) condition and is stored in the convertView using setTag(). In the else loop we just obtain it back using getView() and reuse it.

What is the parent parameter that this method accepts?

The parent is a ViewGroup to which your view created by getView() is finally attached. Now in your case this would be the ListView.

Hope this helps :)

Printing a 2D array in C

...
for(int i=0;i<3;i++){ //Rows
for(int j=0;j<5;j++){ //Cols
 printf("%<...>\t",var);
}
printf("\n");
}
...

considering that <...> would be d,e,f,s,c... etc datatype... X)

Using AES encryption in C#

Try this code, maybe useful.
1.Create New C# Project and add follows code to Form1:

using System;
using System.Windows.Forms;
using System.Security.Cryptography;

namespace ExampleCrypto
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string strOriginalData = string.Empty;
            string strEncryptedData = string.Empty;
            string strDecryptedData = string.Empty;

            strOriginalData = "this is original data 1234567890"; // your original data in here
            MessageBox.Show("ORIGINAL DATA:\r\n" + strOriginalData);

            clsCrypto aes = new clsCrypto();
            aes.IV = "this is your IV";     // your IV
            aes.KEY = "this is your KEY";    // your KEY      
            strEncryptedData = aes.Encrypt(strOriginalData, CipherMode.CBC);    // your cipher mode
            MessageBox.Show("ENCRYPTED DATA:\r\n" + strEncryptedData);

            strDecryptedData = aes.Decrypt(strEncryptedData, CipherMode.CBC);
            MessageBox.Show("DECRYPTED DATA:\r\n" + strDecryptedData);
        }

    }
}

2.Create clsCrypto.cs and copy paste follows code in your class and run your code. I used MD5 to generated Initial Vector(IV) and KEY of AES.

using System;
using System.Security.Cryptography;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Runtime.Remoting.Metadata.W3cXsd2001;

namespace ExampleCrypto
{
    public class clsCrypto
    {
        private string _KEY = string.Empty;
        protected internal string KEY
        {
            get
            {
                return _KEY;
            }
            set
            {
                if (!string.IsNullOrEmpty(value))
                {
                    _KEY = value;
                }
            }
        }

        private string _IV = string.Empty;
        protected internal string IV
        {
            get
            {
                return _IV;
            }
            set
            {
                if (!string.IsNullOrEmpty(value))
                {
                    _IV = value;
                }
            }
        }

        private string CalcMD5(string strInput)
        {
            string strOutput = string.Empty;
            if (!string.IsNullOrEmpty(strInput))
            {
                try
                {
                    StringBuilder strHex = new StringBuilder();
                    using (MD5 md5 = MD5.Create())
                    {
                        byte[] bytArText = Encoding.Default.GetBytes(strInput);
                        byte[] bytArHash = md5.ComputeHash(bytArText);
                        for (int i = 0; i < bytArHash.Length; i++)
                        {
                            strHex.Append(bytArHash[i].ToString("X2"));
                        }
                        strOutput = strHex.ToString();
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
            return strOutput;
        }

        private byte[] GetBytesFromHexString(string strInput)
        {
            byte[] bytArOutput = new byte[] { };
            if ((!string.IsNullOrEmpty(strInput)) && strInput.Length % 2 == 0)
            {
                SoapHexBinary hexBinary = null;
                try
                {
                    hexBinary = SoapHexBinary.Parse(strInput);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
                bytArOutput = hexBinary.Value;
            }
            return bytArOutput;
        }

        private byte[] GenerateIV()
        {
            byte[] bytArOutput = new byte[] { };
            try
            {
                string strIV = CalcMD5(IV);
                bytArOutput = GetBytesFromHexString(strIV);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return bytArOutput;
        }

        private byte[] GenerateKey()
        {
            byte[] bytArOutput = new byte[] { };
            try
            {
                string strKey = CalcMD5(KEY);
                bytArOutput = GetBytesFromHexString(strKey);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            return bytArOutput;
        }

        protected internal string Encrypt(string strInput, CipherMode cipherMode)
        {
            string strOutput = string.Empty;
            if (!string.IsNullOrEmpty(strInput))
            {
                try
                {
                    byte[] bytePlainText = Encoding.Default.GetBytes(strInput);
                    using (RijndaelManaged rijManaged = new RijndaelManaged())
                    {
                        rijManaged.Mode = cipherMode;
                        rijManaged.BlockSize = 128;
                        rijManaged.KeySize = 128;
                        rijManaged.IV = GenerateIV();
                        rijManaged.Key = GenerateKey();
                        rijManaged.Padding = PaddingMode.Zeros;
                        ICryptoTransform icpoTransform = rijManaged.CreateEncryptor(rijManaged.Key, rijManaged.IV);
                        using (MemoryStream memStream = new MemoryStream())
                        {
                            using (CryptoStream cpoStream = new CryptoStream(memStream, icpoTransform, CryptoStreamMode.Write))
                            {
                                cpoStream.Write(bytePlainText, 0, bytePlainText.Length);
                                cpoStream.FlushFinalBlock();
                            }
                            strOutput = Encoding.Default.GetString(memStream.ToArray());
                        }
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
            return strOutput;
        }

        protected internal string Decrypt(string strInput, CipherMode cipherMode)
        {
            string strOutput = string.Empty;
            if (!string.IsNullOrEmpty(strInput))
            {
                try
                {
                    byte[] byteCipherText = Encoding.Default.GetBytes(strInput);
                    byte[] byteBuffer = new byte[strInput.Length];
                    using (RijndaelManaged rijManaged = new RijndaelManaged())
                    {
                        rijManaged.Mode = cipherMode;
                        rijManaged.BlockSize = 128;
                        rijManaged.KeySize = 128;
                        rijManaged.IV = GenerateIV();
                        rijManaged.Key = GenerateKey();
                        rijManaged.Padding = PaddingMode.Zeros;
                        ICryptoTransform icpoTransform = rijManaged.CreateDecryptor(rijManaged.Key, rijManaged.IV);
                        using (MemoryStream memStream = new MemoryStream(byteCipherText))
                        {
                            using (CryptoStream cpoStream = new CryptoStream(memStream, icpoTransform, CryptoStreamMode.Read))
                            {
                                cpoStream.Read(byteBuffer, 0, byteBuffer.Length);
                            }
                            strOutput = Encoding.Default.GetString(byteBuffer);
                        }
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
            return strOutput;
        }

    }
}

Using git to get just the latest revision

Alternate solution to doing shallow clone (git clone --depth=1 <URL>) would be, if remote side supports it, to use --remote option of git archive:

$ git archive --format=tar --remote=<repository URL> HEAD | tar xf -

Or, if remote repository in question is browse-able using some web interface like gitweb or GitHub, then there is a chance that it has 'snapshot' feature, and you can download latest version (without versioning information) from web interface.

Find the maximum value in a list of tuples in Python

Use max():

 
Using itemgetter():

In [53]: lis=[(101, 153), (255, 827), (361, 961)]

In [81]: from operator import itemgetter

In [82]: max(lis,key=itemgetter(1))[0]    #faster solution
Out[82]: 361

using lambda:

In [54]: max(lis,key=lambda item:item[1])
Out[54]: (361, 961)

In [55]: max(lis,key=lambda item:item[1])[0]
Out[55]: 361

timeit comparison:

In [30]: %timeit max(lis,key=itemgetter(1))
1000 loops, best of 3: 232 us per loop

In [31]: %timeit max(lis,key=lambda item:item[1])
1000 loops, best of 3: 556 us per loop

Why is my variable unaltered after I modify it inside of a function? - Asynchronous code reference

To state the obvious, the cup represents outerScopeVar.

Asynchronous functions be like...

asynchronous call for coffee

How to convert jsonString to JSONObject in Java

NOTE that GSON with deserializing an interface will result in exception like below.

"java.lang.RuntimeException: Unable to invoke no-args constructor for interface XXX. Register an InstanceCreator with Gson for this type may fix this problem."

While deserialize; GSON don't know which object has to be intantiated for that interface.

This is resolved somehow here.

However FlexJSON has this solution inherently. while serialize time it is adding class name as part of json like below.

{
    "HTTPStatus": "OK",
    "class": "com.XXX.YYY.HTTPViewResponse",
    "code": null,
    "outputContext": {
        "class": "com.XXX.YYY.ZZZ.OutputSuccessContext",
        "eligible": true
    }
}

So JSON will be cumber some; but you don't need write InstanceCreator which is required in GSON.

Securing a password in a properties file

Actually, this is a duplicate of Encrypt Password in Configuration Files?.

The best solution I found so far is in this answert: https://stackoverflow.com/a/1133815/1549977

Pros: Password is saved a a char array, not as a string. It's still not good, but better than anything else.

How to kill an application with all its activities?

When the user wishes to exit all open activities, they should press a button which loads the first Activity that runs when your app starts, in my case "LoginActivity".

Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("EXIT", true);
startActivity(intent);

The above code clears all the activities except for LoginActivity. LoginActivity is the first activity that is brought up when the user runs the program. Then put this code inside the LoginActivity's onCreate, to signal when it should self destruct when the 'Exit' message is passed.

    if (getIntent().getBooleanExtra("EXIT", false)) {
         finish();
    }

The answer you get to this question from the Android platform is: "Don't make an exit button. Finish activities the user no longer wants, and the Activity manager will clean them up as it sees fit."

How to define relative paths in Visual Studio Project?

By default, all paths you define will be relative. The question is: relative to what? There are several options:

  1. Specifying a file or a path with nothing before it. For example: "mylib.lib". In that case, the file will be searched at the Output Directory.
  2. If you add "..\", the path will be calculated from the actual path where the .sln file resides.

Please note that following a macro such as $(SolutionDir) there is no need to add a backward slash "\". Just use $(SolutionDir)mylibdir\mylib.lib. In case you just can't get it to work, open the project file externally from Notepad and check it.

How to run a Command Prompt command with Visual Basic code?

Here is an example:

Process.Start("CMD", "/C Pause")


/C  Carries out the command specified by string and then terminates
/K  Carries out the command specified by string but remains

And here is a extended function: (Notice the comment-lines using CMD commands.)

#Region " Run Process Function "

' [ Run Process Function ]
'
' // By Elektro H@cker
'
' Examples :
'
' MsgBox(Run_Process("Process.exe")) 
' MsgBox(Run_Process("Process.exe", "Arguments"))
' MsgBox(Run_Process("CMD.exe", "/C Dir /B", True))
' MsgBox(Run_Process("CMD.exe", "/C @Echo OFF & For /L %X in (0,1,50000) Do (Echo %X)", False, False))
' MsgBox(Run_Process("CMD.exe", "/C Dir /B /S %SYSTEMDRIVE%\*", , False, 500))
' If Run_Process("CMD.exe", "/C Dir /B", True).Contains("File.txt") Then MsgBox("File found")

Private Function Run_Process(ByVal Process_Name As String, _
                             Optional Process_Arguments As String = Nothing, _
                             Optional Read_Output As Boolean = False, _
                             Optional Process_Hide As Boolean = False, _
                             Optional Process_TimeOut As Integer = 999999999)

    ' Returns True if "Read_Output" argument is False and Process was finished OK
    ' Returns False if ExitCode is not "0"
    ' Returns Nothing if process can't be found or can't be started
    ' Returns "ErrorOutput" or "StandardOutput" (In that priority) if Read_Output argument is set to True.

    Try

        Dim My_Process As New Process()
        Dim My_Process_Info As New ProcessStartInfo()

        My_Process_Info.FileName = Process_Name ' Process filename
        My_Process_Info.Arguments = Process_Arguments ' Process arguments
        My_Process_Info.CreateNoWindow = Process_Hide ' Show or hide the process Window
        My_Process_Info.UseShellExecute = False ' Don't use system shell to execute the process
        My_Process_Info.RedirectStandardOutput = Read_Output '  Redirect (1) Output
        My_Process_Info.RedirectStandardError = Read_Output ' Redirect non (1) Output
        My_Process.EnableRaisingEvents = True ' Raise events
        My_Process.StartInfo = My_Process_Info
        My_Process.Start() ' Run the process NOW

        My_Process.WaitForExit(Process_TimeOut) ' Wait X ms to kill the process (Default value is 999999999 ms which is 277 Hours)

        Dim ERRORLEVEL = My_Process.ExitCode ' Stores the ExitCode of the process
        If Not ERRORLEVEL = 0 Then Return False ' Returns the Exitcode if is not 0

        If Read_Output = True Then
            Dim Process_ErrorOutput As String = My_Process.StandardOutput.ReadToEnd() ' Stores the Error Output (If any)
            Dim Process_StandardOutput As String = My_Process.StandardOutput.ReadToEnd() ' Stores the Standard Output (If any)
            ' Return output by priority
            If Process_ErrorOutput IsNot Nothing Then Return Process_ErrorOutput ' Returns the ErrorOutput (if any)
            If Process_StandardOutput IsNot Nothing Then Return Process_StandardOutput ' Returns the StandardOutput (if any)
        End If

    Catch ex As Exception
        'MsgBox(ex.Message)
        Return Nothing ' Returns nothing if the process can't be found or started.
    End Try

    Return True ' Returns True if Read_Output argument is set to False and the process finished without errors.

End Function

#End Region

How to delete cookies on an ASP.NET website

You should never store password as a cookie. To delete a cookie, you really just need to modify and expire it. You can't really delete it, ie, remove it from the user's disk.

Here is a sample:

HttpCookie aCookie;
    string cookieName;
    int limit = Request.Cookies.Count;
    for (int i=0; i<limit; i++)
    {
        cookieName = Request.Cookies[i].Name;
        aCookie = new HttpCookie(cookieName);
        aCookie.Expires = DateTime.Now.AddDays(-1); // make it expire yesterday
        Response.Cookies.Add(aCookie); // overwrite it
    }

Embedding DLLs in a compiled executable

It's possible but not all that easy, to create a hybrid native/managed assembly in C#. Were you using C++ instead it'd be a lot easier, as the Visual C++ compiler can create hybrid assemblies as easily as anything else.

Unless you have a strict requirement to produce a hybrid assembly, I'd agree with MusiGenesis that this isn't really worth the trouble to do with C#. If you need to do it, perhaps look at moving to C++/CLI instead.

Python Replace \\ with \

It's because, even in "raw" strings (=strings with an r before the starting quote(s)), an unescaped escape character cannot be the last character in the string. This should work instead:

'\\ '[0]

How to add items to array in nodejs

Check out Javascript's Array API for details on the exact syntax for Array methods. Modifying your code to use the correct syntax would be:

var array = [];
calendars.forEach(function(item) {
    array.push(item.id);
});

console.log(array);

You can also use the map() method to generate an Array filled with the results of calling the specified function on each element. Something like:

var array = calendars.map(function(item) {
    return item.id;
});

console.log(array);

And, since ECMAScript 2015 has been released, you may start seeing examples using let or const instead of var and the => syntax for creating functions. The following is equivalent to the previous example (except it may not be supported in older node versions):

let array = calendars.map(item => item.id);
console.log(array);

Pip Install not installing into correct directory?

Virtualenv is your friend

Even if you want to add a package to your primary install, it's still best to do it in a virtual environment first, to ensure compatibility with your other packages. However, if you get familiar with virtualenv, you'll probably find there's really no reason to install anything in your base install.

convert array into DataFrame in Python

In general you can use pandas rename function here. Given your dataframe you could change to a new name like this. If you had more columns you could also rename those in the dictionary. The 0 is the current name of your column

import pandas as pd    
import numpy as np   
e = np.random.normal(size=100)  
e_dataframe = pd.DataFrame(e)      

e_dataframe.rename(index=str, columns={0:'new_column_name'})

What is the most efficient string concatenation method in python?

One Year later, let's test mkoistinen's answer with python 3.4.3:

  • plus 0.963564149000 (95.83% as fast)
  • join 0.923408469000 (100.00% as fast)
  • form 1.501130934000 (61.51% as fast)
  • intp 1.019677452000 (90.56% as fast)

Nothing changed. Join is still the fastest method. With intp being arguably the best choice in terms of readability you might want to use intp nevertheless.

Fitting iframe inside a div

Would this CSS fix it?

iframe {
    display:block;
    width:100%;
}

From this example: http://jsfiddle.net/HNyJS/2/show/

How to get a DOM Element from a JQuery Selector

Edit: seems I was wrong in assuming you could not get the element. As others have posted here, you can get it with:

$('#element').get(0);

I have verified this actually returns the DOM element that was matched.

Running Command Line in Java

what about

public class CmdExec {

public static Scanner s = null;


public static void main(String[] args) throws InterruptedException, IOException {
    s = new Scanner(System.in);
    System.out.print("$ ");
    String cmd = s.nextLine();
    final Process p = Runtime.getRuntime().exec(cmd);

    new Thread(new Runnable() {
        public void run() {
            BufferedReader input = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line = null; 

            try {
                while ((line = input.readLine()) != null) {
                    System.out.println(line);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    p.waitFor();
     }

 }

HTML not loading CSS file

As per you said your both files are in same directory. 1. index.html and 2. style.css

I have copied your code and run it in my local machine its working fine there is no issues.

According to me your browser is not refreshing the file so you can refresh/reload the entire page by pressing CTRL + F5 in windows for mac CMD + R.

Try it if still getting problem then you can test it by using firebug tool for firefox.

For IE8 and Google Chrome you can check it by pressing F12 your developer tool will pop-up and you can see the Html and css.

Still you have any problem please comment so we can help you.

Good Free Alternative To MS Access

The issue is finding an alternative to MS Access that includes a visual, drag and drop development environment with a "reasonable" database where the whole kit and caboodle can be deployed free of charge.

My first suggestion would be to look at this very complete list of MS Access alternatives (many of which are free), followed by a gander at this list of open source database development tools on osalt.com.

My second suggestion would be to check out WaveMaker, which is sort of an open source PowerBuilder for the cloud (disclaimer: I work there so should not be considered to be an unbiased source of information ;-)

WaveMaker combines a drag and drop IDE with an open source Java back end. It is licensed under the Apache license and boasts a 15,000-strong developer community.

Why "net use * /delete" does not work but waits for confirmation in my PowerShell script?

Try this:

net use * /delete /y

The /y key makes it select Yes in prompt silently

How to call multiple JavaScript functions in onclick event?

ES6 React

<MenuItem
  onClick={() => {
    this.props.toggleTheme();
    this.handleMenuClose();
  }}
>

How do I convert special UTF-8 chars to their iso-8859-1 equivalent using javascript?

Since the question on how to convert from ISO-8859-1 to UTF-8 is closed because of this one I'm going to post my solution here.

The problem is when you try to GET anything by using XMLHttpRequest, if the XMLHttpRequest.responseType is "text" or empty, the XMLHttpRequest.response is transformed to a DOMString and that's were things break up. After, it's almost impossible to reliably work with that string.

Now, if the content from the server is ISO-8859-1 you'll have to force the response to be of type "Blob" and later convert this to DOMSTring. For example:

var ajax = new XMLHttpRequest();
ajax.open('GET', url, true);
ajax.responseType = 'blob';
ajax.onreadystatechange = function(){
    ...
    if(ajax.responseType === 'blob'){
        // Convert the blob to a string
        var reader = new window.FileReader();
        reader.addEventListener('loadend', function() {
           // For ISO-8859-1 there's no further conversion required
           Promise.resolve(reader.result);
        });
        reader.readAsBinaryString(ajax.response);
    }
}

Seems like the magic is happening on readAsBinaryString so maybe someone can shed some light on why this works.

Split list into smaller lists (split in half)

If you have a big list, It's better to use itertools and write a function to yield each part as needed:

from itertools import islice

def make_chunks(data, SIZE):
    it = iter(data)
    # use `xragne` if you are in python 2.7:
    for i in range(0, len(data), SIZE):
        yield [k for k in islice(it, SIZE)]

You can use this like:

A = [0, 1, 2, 3, 4, 5, 6]

size = len(A) // 2

for sample in make_chunks(A, size):
    print(sample)

The output is:

[0, 1, 2]
[3, 4, 5]
[6]

Thanks to @thefourtheye and @Bede Constantinides

IIS error, Unable to start debugging on the webserver

In my case this problem happened after my windows 10 updated to the latest version

-I have tried most of above solutions but not helped me

-I also checked event viewer to see what error happened.

this is the error related to iis was happened but not found any solution on internet about it after a lot of search

The Module DLL 'C:\WINDOWS\System32\inetsrv\cgi.dll' could not be loaded due to a configuration problem. The current configuration only supports loading images built for a AMD64 processor architecture. The data field contains the error number. To learn more about this issue, including how to troubleshooting this kind of processor architecture mismatch error, see http://go.microsoft.com/fwlink/?LinkId=29349.

enter image description here

The way i solve this problem is changing Enable 32-Bit Applications value to True

by right clicking on DefaultAppPool in IIS Manager and select Advanced Settings

enter image description here

Find if current time falls in a time range

You're very close, the problem is you're comparing a DateTime to a TimeOfDay. What you need to do is add the .TimeOfDay property to the end of your Convert.ToDateTime() functions.

Find the version of an installed npm package

Try with:

npm list --depth 1 --global packagename

What does @media screen and (max-width: 1024px) mean in CSS?

Also worth noting you can use 'em' as well as 'px' - blogs and text based sites do it because then the browser makes layout decisions more relative to the text content.

On Wordpress twentysixteen I wanted my tagline to display on mobiles as well as desktops, so I put this in my child theme style.css

@media screen and (max-width:59em){
    p.site-description {
        display:    block;
    }
}

Conditional Binding: if let error – Initializer for conditional binding must have Optional type

Same applies for guard statements. The same error message lead me to this post and answer (thanks @nhgrif).

The code: Print the last name of the person only if the middle name is less than four characters.

func greetByMiddleName(name: (first: String, middle: String?, last: String?)) {
    guard let Name = name.last where name.middle?.characters.count < 4 else {
        print("Hi there)")
        return
    }
    print("Hey \(Name)!")
}

Until I declared last as an optional parameter I was seeing the same error.

'this' is undefined in JavaScript class methods

In ES2015 a.k.a ES6, class is a syntactic sugar for functions.

If you want to force to set a context for this you can use bind() method. As @chetan pointed, on invocation you can set the context as well! Check the example below:

class Form extends React.Component {
constructor() {
    super();
  }
  handleChange(e) {
    switch (e.target.id) {
      case 'owner':
        this.setState({owner: e.target.value});
        break;
      default:
    }
  }
  render() {
    return (
      <form onSubmit={this.handleNewCodeBlock}>
        <p>Owner:</p> <input onChange={this.handleChange.bind(this)} />
      </form>
    );
  }
}

Here we forced the context inside handleChange() to Form.

How do I write a RGB color value in JavaScript?

try:

parent.childNodes[1].style.color = "rgb(155, 102, 102)"; 

Or

parent.childNodes[1].style.color = "#"+(155).toString(16)+(102).toString(16)+(102).toString(16);

What are the best PHP input sanitizing functions?

what about this

$string = htmlspecialchars(strip_tags($_POST['example']));

or this

$string = htmlentities($_POST['example'], ENT_QUOTES, 'UTF-8');

How to execute .sql file using powershell?

Here is a function that I have in my PowerShell profile for loading SQL snapins:

function Load-SQL-Server-Snap-Ins
{
    try 
    {
        $sqlpsreg="HKLM:\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.SqlServer.Management.PowerShell.sqlps"

        if (!(Test-Path $sqlpsreg -ErrorAction "SilentlyContinue"))
        {
            throw "SQL Server Powershell is not installed yet (part of SQLServer installation)."
        }

        $item = Get-ItemProperty $sqlpsreg
        $sqlpsPath = [System.IO.Path]::GetDirectoryName($item.Path)

        $assemblyList = @(
            "Microsoft.SqlServer.Smo",
            "Microsoft.SqlServer.SmoExtended",
            "Microsoft.SqlServer.Dmf",
            "Microsoft.SqlServer.WmiEnum",
            "Microsoft.SqlServer.SqlWmiManagement",
            "Microsoft.SqlServer.ConnectionInfo ",
            "Microsoft.SqlServer.Management.RegisteredServers",
            "Microsoft.SqlServer.Management.Sdk.Sfc",
            "Microsoft.SqlServer.SqlEnum",
            "Microsoft.SqlServer.RegSvrEnum",
            "Microsoft.SqlServer.ServiceBrokerEnum",
            "Microsoft.SqlServer.ConnectionInfoExtended",
            "Microsoft.SqlServer.Management.Collector",
            "Microsoft.SqlServer.Management.CollectorEnum"
        )

        foreach ($assembly in $assemblyList)
        { 
            $assembly = [System.Reflection.Assembly]::LoadWithPartialName($assembly) 
            if ($assembly -eq $null)
                { Write-Host "`t`t($MyInvocation.InvocationName): Could not load $assembly" }
        }

        Set-Variable -scope Global -name SqlServerMaximumChildItems -Value 0
        Set-Variable -scope Global -name SqlServerConnectionTimeout -Value 30
        Set-Variable -scope Global -name SqlServerIncludeSystemObjects -Value $false
        Set-Variable -scope Global -name SqlServerMaximumTabCompletion -Value 1000

        Push-Location

         if ((Get-PSSnapin -Name SqlServerProviderSnapin100 -ErrorAction SilentlyContinue) -eq $null) 
        { 
            cd $sqlpsPath

            Add-PsSnapin SqlServerProviderSnapin100 -ErrorAction Stop
            Add-PsSnapin SqlServerCmdletSnapin100 -ErrorAction Stop
            Update-TypeData -PrependPath SQLProvider.Types.ps1xml
            Update-FormatData -PrependPath SQLProvider.Format.ps1xml
        }
    } 

    catch 
    {
        Write-Host "`t`t$($MyInvocation.InvocationName): $_" 
    }

    finally
    {
        Pop-Location
    }
}

java create date object using a value string

Try this :-

try{
        String valuee="25/04/2013";
        Date currentDate =new SimpleDateFormat("dd/MM/yyyy").parse(valuee);
        System.out.println("Date is ::"+currentDate);
        }catch(Exception e){
            System.out.println("Error::"+e);
            e.printStackTrace();
        }

Output:-

   Date is ::Thu Apr 25 00:00:00 GMT+05:30 2013

Your value should be proper format.

In your question also you have asked for this below :-

   Date currentDate = new Date(value);

This style of date constructor is already deprecated.So, its no more use.Being we know that Date has 6 constructor.Read more

Func delegate with no return type

Try System.Func<T> and System.Action

How can I read inputs as numbers?

Multiple questions require input for several integers on single line. The best way is to input the whole string of numbers one one line and then split them to integers. Here is a Python 3 version:

a = []
p = input()
p = p.split()      
for i in p:
    a.append(int(i))

Also a list comprehension can be used

p = input().split("whatever the seperator is")

And to convert all the inputs from string to int we do the following

x = [int(i) for i in p]
print(x, end=' ')

shall print the list elements in a straight line.

How to align absolutely positioned element to center?

All you have to do is,

make sure your parent DIV has position:relative

and the element you want center, set it a height and width. use the following CSS

.layer {
    width: 600px; height: 500px;
    display: block;
    position:absolute;
    top:0;
    left: 0;
    right:0;
    bottom: 0;
    margin:auto;
  }
http://jsbin.com/aXEZUgEJ/1/

Share application "link" in Android

This will let you choose from email, whatsapp or whatever.

try { 
    Intent shareIntent = new Intent(Intent.ACTION_SEND);  
    shareIntent.setType("text/plain");
    shareIntent.putExtra(Intent.EXTRA_SUBJECT, "My application name");
    String shareMessage= "\nLet me recommend you this application\n\n";
    shareMessage = shareMessage + "https://play.google.com/store/apps/details?id=" + BuildConfig.APPLICATION_ID +"\n\n";
    shareIntent.putExtra(Intent.EXTRA_TEXT, shareMessage);  
    startActivity(Intent.createChooser(shareIntent, "choose one"));
} catch(Exception e) { 
    //e.toString();
}   

How do I convert a datetime to date?

import time
import datetime

# use mktime to step by one day
# end - the last day, numdays - count of days to step back
def gen_dates_list(end, numdays):
  start = end - datetime.timedelta(days=numdays+1)
  end   = int(time.mktime(end.timetuple()))
  start = int(time.mktime(start.timetuple()))
  # 86400 s = 1 day
  return xrange(start, end, 86400)

# if you need reverse the list of dates
for dt in reversed(gen_dates_list(datetime.datetime.today(), 100)):
    print datetime.datetime.fromtimestamp(dt).date()

Undefined symbols for architecture arm64

I ran into the same/similar issue implementing AVPictureInPictureController and the issue was that I wasn't linking the AVKit framework in my project.

The error message was:

Undefined symbols for architecture armv7:
   "_OBJC_CLASS_$_AVPictureInPictureController", referenced from:
       objc-class-ref in yourTarget.a(yourObject.o)
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

The Solution:

  1. Go to your Project
  2. Select your Target
  3. Then, go to Build Phases
  4. Open Link Binary With Libraries
  5. Finally, just add + the AVKit framework / any other framework.

Hopefully this helps someone else running into a similar issue I had.

Remote Linux server to remote linux server dir copy. How?

Use rsync so that you can continue if the connection gets broken. And if something changes you can copy them much faster too!

Rsync works with SSH so your copy operation is secure.

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

In Ubuntu 16.04 (MySQL version 5.7.13) I was able to resolve the problem with the steps below:

  1. Follow the instructions from the in section B.5.3.2.2 Resetting the Root Password: Unix and Unix-Like Systems MySQL 5.7 reference manual

  2. When I tried #sudo mysqld_safe --init-file=/home/me/mysql-init & it failed. The error was in /var/log/mysql/error.log

    2016-08-10T11:41:20.421946Z 0 [Note] Execution of init_file '/home/me/mysql/mysql-init' started. 2016-08-10T11:41:20.422070Z 0 [ERROR] /usr/sbin/mysqld: File '/home/me/mysql/mysql-init' not found (Errcode: 13 - Permission denied) 2016-08-10T11:41:20.422096Z 0 [ERROR] Aborting

The file permission of mysql-init was not the problem, need to edit apparmor permission

  1. Edit by #sudo vi /etc/apparmor.d/usr.sbin.mysqld

    ....
      /var/log/mysql/ r,
      /var/log/mysql/** rw,
    
    
    # Allow user init file
      /home/pranab/mysql/* r,
    
      # Site-specific additions and overrides. See local/README for details.
      #include <local/usr.sbin.mysqld>
    }
    
  2. Do #sudo /etc/init.d/apparmor reload

  3. Start mysqld_safe again try step 2 above. Check /var/log/mysql/error.log make sure there is no error and the mysqld is successfully started

  4. Run #mysql -u root -p

    Enter password:

Enter the password that you specified in mysql-init. You should be able to log in as root now.

  1. Shutdown mysqld_safe by #sudo mysqladmin -u root -p shutdown

  2. Start mysqld normal way by #sudo systemctl start mysql

Visibility of global variables in imported modules

A function uses the globals of the module it's defined in. Instead of setting a = 3, for example, you should be setting module1.a = 3. So, if you want cur available as a global in utilities_module, set utilities_module.cur.

A better solution: don't use globals. Pass the variables you need into the functions that need it, or create a class to bundle all the data together, and pass it when initializing the instance.

Unit test naming best practices

In VS + NUnit I usually create folders in my project to group functional tests together. Then I create unit test fixture classes and name them after the type of functionality I'm testing. The [Test] methods are named along the lines of Can_add_user_to_domain:

- MyUnitTestProject   
  + FTPServerTests <- Folder
   + UserManagerTests <- Test Fixture Class
     - Can_add_user_to_domain  <- Test methods
     - Can_delete_user_from_domain
     - Can_reset_password

batch script - read line by line

This has worked for me in the past and it will even expand environment variables in the file if it can.

for /F "delims=" %%a in (LogName.txt) do (
     echo %%a>>MyDestination.txt
)

Which websocket library to use with Node.js?

Getting the ball rolling with this community wiki answer. Feel free to edit me with your improvements.

  • ws WebSocket server and client for node.js. One of the fastest libraries if not the fastest one.

  • websocket-node WebSocket server and client for node.js

  • websocket-driver-node WebSocket server and client protocol parser node.js - used in faye-websocket-node

  • faye-websocket-node WebSocket server and client for node.js - used in faye and sockjs

  • socket.io WebSocket server and client for node.js + client for browsers + (v0 has newest to oldest fallbacks, v1 of Socket.io uses engine.io) + channels - used in stack.io. Client library tries to reconnect upon disconnection.

  • sockjs WebSocket server and client for node.js and others + client for browsers + newest to oldest fallbacks

  • faye WebSocket server and client for node.js and others + client for browsers + fallbacks + support for other server-side languages

  • deepstream.io clusterable realtime server that handles WebSockets & TCP connections and provides data-sync, pub/sub and request/response

  • socketcluster WebSocket server cluster which makes use of all CPU cores on your machine. For example, if you were to use an xlarge Amazon EC2 instance with 32 cores, you would be able to handle almost 32 times the traffic on a single instance.

  • primus Provides a common API for most of the libraries above for easy switching + stability improvements for all of them.

When to use:

  • use the basic WebSocket servers when you want to use the native WebSocket implementations on the clientside, beware of the browser incompatabilities

  • use the fallback libraries when you care about browser fallbacks

  • use the full featured libraries when you care about channels

  • use primus when you have no idea about what to use, are not in the mood for rewriting your application when you need to switch frameworks because of changing project requirements or need additional connection stability.

Where to test:

Firecamp is a GUI testing environment for SocketIO, WS and all major real-time technology. Debug the real-time events while you're developing it.

Where can I download IntelliJ IDEA Color Schemes?

Since it is hard to find good themes for IntelliJ IDEA, I've created this site: https://github.com/sdvoynikov/color-themes (note: site archived to GitHub repo) where there is a large collection of themes. There are 270 themes for now and the site is growing.

Screenshot of the site

P.S.: Help me and other people — do not forget to upvote when you download themes from this site!

How can I limit the visible options in an HTML <select> dropdown?

It is not possible to limit the number of visible elements in the select dropdown (if you use it as dropdown box and not as list).

But you could use javascript/jQuery to replace this selectbox with something else, which just looks like a dropdown box. Then you can handle the height of dropdown as you want.

jNice would be a jQuery plugin which has such features. But there also exists many alternatives for that.

How to insert an item into an array at a specific index (JavaScript)?

For proper functional programming and chaining purposes an invention of Array.prototype.insert() is essential. Actually splice could have been perfect if it had returned the mutated array instead of a totally meaningless empty array. So here it goes

_x000D_
_x000D_
Array.prototype.insert = function(i,...rest){_x000D_
  this.splice(i,0,...rest)_x000D_
  return this_x000D_
}_x000D_
_x000D_
var a = [3,4,8,9];_x000D_
document.write("<pre>" + JSON.stringify(a.insert(2,5,6,7)) + "</pre>");
_x000D_
_x000D_
_x000D_

Well ok the above with the Array.prototype.splice() one mutates the original array and some might complain like "you shouldn't modify what doesn't belong to you" and that might turn out to be right as well. So for the public welfare i would like to give another Array.prototype.insert() which doesn't mutate the original array. Here it goes;

_x000D_
_x000D_
Array.prototype.insert = function(i,...rest){_x000D_
  return this.slice(0,i).concat(rest,this.slice(i));_x000D_
}_x000D_
_x000D_
var a = [3,4,8,9],_x000D_
    b = a.insert(2,5,6,7);_x000D_
console.log(JSON.stringify(a));_x000D_
console.log(JSON.stringify(b));
_x000D_
_x000D_
_x000D_

How to determine whether an object has a given property in JavaScript

Object has property:

If you are testing for properties that are on the object itself (not a part of its prototype chain) you can use .hasOwnProperty():

if (x.hasOwnProperty('y')) { 
  // ......
}

Object or its prototype has a property:

You can use the in operator to test for properties that are inherited as well.

if ('y' in x) {
  // ......
}