Programs & Examples On #Refresher

How to call Stored Procedure in a View?

This construction is not allowed in SQL Server. An inline table-valued function can perform as a parameterized view, but is still not allowed to call an SP like this.

Here's some examples of using an SP and an inline TVF interchangeably - you'll see that the TVF is more flexible (it's basically more like a view than a function), so where an inline TVF can be used, they can be more re-eusable:

CREATE TABLE dbo.so916784 (
    num int
)
GO

INSERT INTO dbo.so916784 VALUES (0)
INSERT INTO dbo.so916784 VALUES (1)
INSERT INTO dbo.so916784 VALUES (2)
INSERT INTO dbo.so916784 VALUES (3)
INSERT INTO dbo.so916784 VALUES (4)
INSERT INTO dbo.so916784 VALUES (5)
INSERT INTO dbo.so916784 VALUES (6)
INSERT INTO dbo.so916784 VALUES (7)
INSERT INTO dbo.so916784 VALUES (8)
INSERT INTO dbo.so916784 VALUES (9)
GO

CREATE PROCEDURE dbo.usp_so916784 @mod AS int
AS 
BEGIN
    SELECT  *
    FROM    dbo.so916784
    WHERE   num % @mod = 0
END
GO

CREATE FUNCTION dbo.tvf_so916784 (@mod AS int)
RETURNS TABLE
    AS
RETURN
    (
     SELECT *
     FROM   dbo.so916784
     WHERE  num % @mod = 0
    )
GO    

EXEC dbo.usp_so916784 3
EXEC dbo.usp_so916784 4

SELECT * FROM dbo.tvf_so916784(3)    
SELECT * FROM dbo.tvf_so916784(4)

DROP FUNCTION dbo.tvf_so916784
DROP PROCEDURE dbo.usp_so916784
DROP TABLE dbo.so916784

Task not serializable: java.io.NotSerializableException when calling function outside closure only on classes not objects

RDDs extend the Serialisable interface, so this is not what's causing your task to fail. Now this doesn't mean that you can serialise an RDD with Spark and avoid NotSerializableException

Spark is a distributed computing engine and its main abstraction is a resilient distributed dataset (RDD), which can be viewed as a distributed collection. Basically, RDD's elements are partitioned across the nodes of the cluster, but Spark abstracts this away from the user, letting the user interact with the RDD (collection) as if it were a local one.

Not to get into too many details, but when you run different transformations on a RDD (map, flatMap, filter and others), your transformation code (closure) is:

  1. serialized on the driver node,
  2. shipped to the appropriate nodes in the cluster,
  3. deserialized,
  4. and finally executed on the nodes

You can of course run this locally (as in your example), but all those phases (apart from shipping over network) still occur. [This lets you catch any bugs even before deploying to production]

What happens in your second case is that you are calling a method, defined in class testing from inside the map function. Spark sees that and since methods cannot be serialized on their own, Spark tries to serialize the whole testing class, so that the code will still work when executed in another JVM. You have two possibilities:

Either you make class testing serializable, so the whole class can be serialized by Spark:

import org.apache.spark.{SparkContext,SparkConf}

object Spark {
  val ctx = new SparkContext(new SparkConf().setAppName("test").setMaster("local[*]"))
}

object NOTworking extends App {
  new Test().doIT
}

class Test extends java.io.Serializable {
  val rddList = Spark.ctx.parallelize(List(1,2,3))

  def doIT() =  {
    val after = rddList.map(someFunc)
    after.collect().foreach(println)
  }

  def someFunc(a: Int) = a + 1
}

or you make someFunc function instead of a method (functions are objects in Scala), so that Spark will be able to serialize it:

import org.apache.spark.{SparkContext,SparkConf}

object Spark {
  val ctx = new SparkContext(new SparkConf().setAppName("test").setMaster("local[*]"))
}

object NOTworking extends App {
  new Test().doIT
}

class Test {
  val rddList = Spark.ctx.parallelize(List(1,2,3))

  def doIT() =  {
    val after = rddList.map(someFunc)
    after.collect().foreach(println)
  }

  val someFunc = (a: Int) => a + 1
}

Similar, but not the same problem with class serialization can be of interest to you and you can read on it in this Spark Summit 2013 presentation.

As a side note, you can rewrite rddList.map(someFunc(_)) to rddList.map(someFunc), they are exactly the same. Usually, the second is preferred as it's less verbose and cleaner to read.

EDIT (2015-03-15): SPARK-5307 introduced SerializationDebugger and Spark 1.3.0 is the first version to use it. It adds serialization path to a NotSerializableException. When a NotSerializableException is encountered, the debugger visits the object graph to find the path towards the object that cannot be serialized, and constructs information to help user to find the object.

In OP's case, this is what gets printed to stdout:

Serialization stack:
    - object not serializable (class: testing, value: testing@2dfe2f00)
    - field (class: testing$$anonfun$1, name: $outer, type: class testing)
    - object (class testing$$anonfun$1, <function1>)

Set keyboard caret position in html textbox

I would fix the conditions like below:

function setCaretPosition(elemId, caretPos)
{
 var elem = document.getElementById(elemId);
 if (elem)
 {
  if (typeof elem.createTextRange != 'undefined')
  {
   var range = elem.createTextRange();
   range.move('character', caretPos);
   range.select();
  }
  else
  {
   if (typeof elem.selectionStart != 'undefined')
    elem.selectionStart = caretPos;
   elem.focus();
  }
 }
}

How to remove word wrap from textarea?

The following CSS based solution works for me:

<html>
 <head>
  <style type='text/css'>
   textarea {
    white-space: nowrap;
    overflow:    scroll;
    overflow-y:  hidden;
    overflow-x:  scroll;
    overflow:    -moz-scrollbars-horizontal;
   }
  </style>
 </head>
 <body>
  <form>
   <textarea>This is a long line of text for testing purposes...</textarea>
  </form>
 </body>
</html>

Are there any Java method ordering conventions?

My "convention": static before instance, public before private, constructor before methods, but main method at the bottom (if present).

Refresh Page and Keep Scroll Position

document.location.reload() stores the position, see in the docs.

Add additional true parameter to force reload, but without restoring the position.

document.location.reload(true)

MDN docs:

The forcedReload flag changes how some browsers handle the user's scroll position. Usually reload() restores the scroll position afterward, but forced mode can scroll back to the top of the page, as if window.scrollY === 0.

Lambda expression to convert array/List of String to array/List of Integers

EDIT: As pointed out in the comments, this is a much simpler version: Arrays.stream(stringArray).mapToInt(Integer::parseInt).toArray() This way we can skip the whole conversion to and from a list.


I found another one line solution, but it's still pretty slow (takes about 100 times longer than a for cycle - tested on an array of 6000 0's)

String[] stringArray = ...
int[] out= Arrays.asList(stringArray).stream().map(Integer::parseInt).mapToInt(i->i).toArray();

What this does:

  1. Arrays.asList() converts the array to a List
  2. .stream converts it to a Stream (needed to perform a map)
  3. .map(Integer::parseInt) converts all the elements in the stream to Integers
  4. .mapToInt(i->i) converts all the Integers to ints (you don't have to do this if you only want Integers)
  5. .toArray() converts the Stream back to an array

Disabling Warnings generated via _CRT_SECURE_NO_DEPRECATE

you can disable security check. go to

Project -> Properties -> Configuration properties -> C/C++ -> Code Generation -> Security Check

and select Disable Security Check (/GS-)

Conversion of a varchar data type to a datetime data type resulted in an out-of-range value in SQL query

some problem, but I find the solution, this is :


2 February Feb 28 (29 in leap years)

this is my code

 public string GetCountArchiveByMonth(int iii)
        {
// iii: is number of months, use any number other than (**2**)

            con.Open();

            SqlCommand cmd10 = con.CreateCommand();
            cmd10.CommandType = CommandType.Text;
            cmd10.CommandText = "select count(id_post) from posts where dateadded between CONVERT(VARCHAR, @start, 103) and CONVERT(VARCHAR, @end, 103)";
            cmd10.Parameters.AddWithValue("@start", "" + iii + "/01/2019");
            cmd10.Parameters.AddWithValue("@end", "" + iii + "/30/2019");
            string result = cmd10.ExecuteScalar().ToString();

            con.Close();

            return result;
        }

now for test

 lbl1.Text = GetCountArchiveByMonth(**7**).ToString();  // here use any number other than (**2**)

**

because of check **February** is maxed 28 days,

**

How to print spaces in Python?

If you need to separate certain elements with spaces you could do something like

print "hello", "there"

Notice the comma between "hello" and "there".

If you want to print a new line (i.e. \n) you could just use print without any arguments.

How is TeamViewer so fast?

Oddly. but in my experience TeamViewer is not faster/more responsive than VNC, only easier to setup. I have a couple of win-boxen that I VNC over OpenVPN into (so there is another overhead layer) and that's on cheap Cable (512 up) and I find properly setup TightVNC to be much more responsive than TeamViewer to same boxen. RDP (naturally) even more so since by large part it sends GUI draw commands instead of bitmap tiles.

Which brings us to:

  1. Why are you not using VNC? There are plethora of open source solutions, and Tight is probably on top of it's game right now.

  2. Advanced VNC implementations use lossy compression and that seems to achieve better results than your choice of PNG. Also, IIRC the rest of the payload is also squashed using zlib. Bothj Tight and UltraVNC have very optimized algos, especially for windows. On top of that Tight is open-source.

  3. If win boxen are your primary target RDP may be a better option, and has an opensource implementation (rdesktop)

  4. If *nix boxen are your primary target NX may be a better option and has an open source implementation (FreeNX, albeit not as optimised as NoMachine's proprietary product).

If compressing JPEG is a performance issue for your algo, I'm pretty sure that image comparison would still take away some performance. I'd bet they use best-case compression for every specific situation ie lossy for large frames, some quick and dirty internall losless for smaller ones, compare bits of images and send only diffs of sort and bunch of other optimisation tricks.

And a lot of those tricks must be present in Tight > 2.0 since again, in my experience it beats the hell out of TeamViewer performance wyse, YMMV.

Also the choice of a JIT compiled runtime over something like C++ might take a slice from your performance edge, especially in memory constrained machines (a lot of performance tuning goes to the toilet when windows start using the pagefile intensively). And you will need memory to keep previous image states for internal comparison atop of what DF mirage gives you.

Memory Allocation "Error: cannot allocate vector of size 75.1 Mb"

gc() can help

saving data as .RData, closing, re-opening R, and loading the RData can help.

see my answer here: https://stackoverflow.com/a/24754706/190791 for more details

Adding a parameter to the URL with JavaScript

Easiest solution, works if you have already a tag or not, and removes it automatically so it wont keep adding equal tags, have fun

function changeURL(tag)
{
if(window.location.href.indexOf("?") > -1) {
    if(window.location.href.indexOf("&"+tag) > -1){

        var url = window.location.href.replace("&"+tag,"")+"&"+tag;
    }
    else
    {
        var url = window.location.href+"&"+tag;
    }
}else{
    if(window.location.href.indexOf("?"+tag) > -1){

        var url = window.location.href.replace("?"+tag,"")+"?"+tag;
    }
    else
    {
        var url = window.location.href+"?"+tag;
    }
}
  window.location = url;
}

THEN

changeURL("i=updated");

Get GPS location from the web browser

If you use the Geolocation API, it would be as simple as using the following code.

navigator.geolocation.getCurrentPosition(function(location) {
  console.log(location.coords.latitude);
  console.log(location.coords.longitude);
  console.log(location.coords.accuracy);
});

You may also be able to use Google's Client Location API.

This issue has been discussed in Is it possible to detect a mobile browser's GPS location? and Get position data from mobile browser. You can find more information there.

JSON Parse File Path

Since it is in the directory data/, You need to do:

file path is '../../data/file.json'

$.getJSON('../../data/file.json', function(data) {         
    alert(data);
});

Pure JS:

   var request = new XMLHttpRequest();
   request.open("GET", "../../data/file.json", false);
   request.send(null)
   var my_JSON_object = JSON.parse(request.responseText);
   alert (my_JSON_object.result[0]);

How to read pickle file?

Pickle serializes a single object at a time, and reads back a single object - the pickled data is recorded in sequence on the file.

If you simply do pickle.load you should be reading the first object serialized into the file (not the last one as you've written).

After unserializing the first object, the file-pointer is at the beggining of the next object - if you simply call pickle.load again, it will read that next object - do that until the end of the file.

objects = []
with (open("myfile", "rb")) as openfile:
    while True:
        try:
            objects.append(pickle.load(openfile))
        except EOFError:
            break

How do I create a unique ID in Java?

Here's my two cent's worth: I've previously implemented an IdFactory class that created IDs in the format [host name]-[application start time]-[current time]-[discriminator]. This largely guaranteed that IDs were unique across JVM instances whilst keeping the IDs readable (albeit quite long). Here's the code in case it's of any use:

public class IdFactoryImpl implements IdFactory {
  private final String hostName;
  private final long creationTimeMillis;
  private long lastTimeMillis;
  private long discriminator;

  public IdFactoryImpl() throws UnknownHostException {
    this.hostName = InetAddress.getLocalHost().getHostAddress();
    this.creationTimeMillis = System.currentTimeMillis();
    this.lastTimeMillis = creationTimeMillis;
  }

  public synchronized Serializable createId() {
    String id;
    long now = System.currentTimeMillis();

    if (now == lastTimeMillis) {
      ++discriminator;
    } else {
      discriminator = 0;
    }

    // creationTimeMillis used to prevent multiple instances of the JVM
    // running on the same host returning clashing IDs.
    // The only way a clash could occur is if the applications started at
    // exactly the same time.
    id = String.format("%s-%d-%d-%d", hostName, creationTimeMillis, now, discriminator);
    lastTimeMillis = now;

    return id;
  }

  public static void main(String[] args) throws UnknownHostException {
    IdFactory fact = new IdFactoryImpl();

    for (int i=0; i<1000; ++i) {
      System.err.println(fact.createId());
    }
  }
}

IllegalMonitorStateException on wait() call

You need to be in a synchronized block in order for Object.wait() to work.

Also, I recommend looking at the concurrency packages instead of the old school threading packages. They are safer and way easier to work with.

Happy coding.

EDIT

I assumed you meant Object.wait() as your exception is what happens when you try to gain access without holding the objects lock.

VS 2012: Scroll Solution Explorer to current file

If you don't have ReSharper installed and still want to use the shortcut Shift+Alt+L to move focus to the current file in Solution Explorer in Visual Studio 2013 then please follow these steps:

  1. Go to Tools->Options and search for "Keyboard" in the Search Options textbox:

enter image description here

  1. In the Show commands containing box type "solutionexplorer" and then in the list below look for the SyncWithActiveDocument command: enter image description here

  2. Click in textbox under "Press short keys" label and press: Shift+Alt+L and click the Assign button and you are done: enter image description here

To verify open any file in Visual Studio and press the shortcut keys Shift+Alt+L and you'll see the file in the solution explorer. Enjoy!

C# How can I check if a URL exists/is valid?

I have always found Exceptions are much slower to be handled.

Perhaps a less intensive way would yeild a better, faster, result?

public bool IsValidUri(Uri uri)
{

    using (HttpClient Client = new HttpClient())
    {

    HttpResponseMessage result = Client.GetAsync(uri).Result;
    HttpStatusCode StatusCode = result.StatusCode;

    switch (StatusCode)
    {

        case HttpStatusCode.Accepted:
            return true;
        case HttpStatusCode.OK:
            return true;
         default:
            return false;
        }
    }
}

Then just use:

IsValidUri(new Uri("http://www.google.com/censorship_algorithm"));

How to convert/parse from String to char in java?

You can use the .charAt(int) function with Strings to retrieve the char value at any index. If you want to convert the String to a char array, try calling .toCharArray() on the String. If the string is 1 character long, just take that character by calling .charAt(0) (or .First() in C#).

initialize a const array in a class initializer in C++

With C++11 the answer to this question has now changed and you can in fact do:

struct a {
    const int b[2];
    // other bits follow

    // and here's the constructor
    a();
};

a::a() :
    b{2,3}
{
     // other constructor work
}

int main() {
 a a;
}

How to clear mysql screen console in windows?

Open Properties by clicking the upper left console window icon, go to Layout tab, take note of the value set in Screen Buffer Size->Height, and change it to 1. Click OK.
You'll see a 1 row console. Open Properties again and change that value back to what it had before. Resize the console down and you'll have a clean console.

enter image description here

django import error - No module named core.management

I solved this problem by using 'django-admin' command as following instead:

django-admin startproject _project_name

just remove the ".py" attached to "django-admin"

How do I protect javascript files?

I agree with everyone else here: With JS on the client, the cat is out of the bag and there is nothing completely foolproof that can be done.

Having said that; in some cases I do this to put some hurdles in the way of those who want to take a look at the code. This is how the algorithm works (roughly)

  1. The server creates 3 hashed and salted values. One for the current timestamp, and the other two for each of the next 2 seconds. These values are sent over to the client via Ajax to the client as a comma delimited string; from my PHP module. In some cases, I think you can hard-bake these values into a script section of HTML when the page is formed, and delete that script tag once the use of the hashes is over The server is CORS protected and does all the usual SERVER_NAME etc check (which is not much of a protection but at least provides some modicum of resistance to script kiddies).

  2. Also it would be nice, if the the server checks if there was indeed an authenticated user's client doing this

  3. The client then sends the same 3 hashed values back to the server thru an ajax call to fetch the actual JS that I need. The server checks the hashes against the current time stamp there... The three values ensure that the data is being sent within the 3 second window to account for latency between the browser and the server

  4. The server needs to be convinced that one of the hashes is matched correctly; and if so it would send over the crucial JS back to the client. This is a simple, crude "One time use Password" without the need for any database at the back end.

  5. This means, that any hacker has only the 3 second window period since the generation of the first set of hashes to get to the actual JS code.

  6. The entire client code can be inside an IIFE function so some of the variables inside the client are even more harder to read from the Inspector console

    This is not any deep solution: A determined hacker can register, get an account and then ask the server to generate the first three hashes; by doing tricks to go around Ajax and CORS; and then make the client perform the second call to get to the actual code -- but it is a reasonable amount of work.

Moreover, if the Salt used by the server is based on the login credentials; the server may be able to detect who is that user who tried to retreive the sensitive JS (The server needs to do some more additional work regarding the behaviour of the user AFTER the sensitive JS was retreived, and block the person if the person, say for example, did not do some other activity which was expected)

An old, crude version of this was done for a hackathon here: http://planwithin.com/demo/tadr.html That wil not work in case the server detects too much latency, and it goes beyond the 3 second window period

How to auto import the necessary classes in Android Studio with shortcut?

You can also use Eclipse's keyboard shortcuts: just go on preferences > keymap and choose Eclipse from the drop-down menu. And all your Eclipse shortcuts will be used in here.

Twitter bootstrap remote modal shows same content every time

I've added something like this, because the older content is shown until the new one appears, with .html('') inside the .modal-content will clear the HTML inside, hope it helps

$('#myModal').on('hidden.bs.modal', function () {
   $('#myModal').removeData('bs.modal');
   $('#myModal').find('.modal-content').html('');
});

My C# application is returning 0xE0434352 to Windows Task Scheduler but it is not crashing

Hans Passant was correct, I added a handler for AppDomain.CurrentDomain.UnhandledException as described here http://msdn.microsoft.com/en-us/library/system.appdomain.unhandledexception(v=vs.71).aspx I was able to find the exception that was occurring and corrected it.

correct way to use super (argument passing)

If you're going to have a lot of inheritence (that's the case here) I suggest you to pass all parameters using **kwargs, and then pop them right after you use them (unless you need them in upper classes).

class First(object):
    def __init__(self, *args, **kwargs):
        self.first_arg = kwargs.pop('first_arg')
        super(First, self).__init__(*args, **kwargs)

class Second(First):
    def __init__(self, *args, **kwargs):
        self.second_arg = kwargs.pop('second_arg')
        super(Second, self).__init__(*args, **kwargs)

class Third(Second):
    def __init__(self, *args, **kwargs):
        self.third_arg = kwargs.pop('third_arg')
        super(Third, self).__init__(*args, **kwargs)

This is the simplest way to solve those kind of problems.

third = Third(first_arg=1, second_arg=2, third_arg=3)

Converting char* to float or double

Code posted by you is correct and should have worked. But check exactly what you have in the char*. If the correct value is to big to be represented, functions will return a positive or negative HUGE_VAL. Check what you have in the char* against maximum values that float and double can represent on your computer.

Check this page for strtod reference and this page for atof reference.

I have tried the example you provided in both Windows and Linux and it worked fine.

Angular 2 Hover event

For handling the event on overing, you can try something like this (it works for me):

In the Html template:

<div (mouseenter)="onHovering($event)" (mouseleave)="onUnovering($event)">
  <img src="../../../contents/ctm-icons/alarm.svg" class="centering-me" alt="Alerts" />
</div>

In the angular component:

    onHovering(eventObject) {
    console.log("AlertsBtnComponent.onHovering:");
    var regExp = new RegExp(".svg" + "$");

    var srcObj = eventObject.target.offsetParent.children["0"];
    if (srcObj.tagName == "IMG") {
        srcObj.setAttribute("src", srcObj.getAttribute("src").replace(regExp, "_h.svg"));       
    }

   }
   onUnovering(eventObject) {
    console.log("AlertsBtnComponent.onUnovering:");
    var regExp = new RegExp("_h.svg" + "$");

    var srcObj = eventObject.target.offsetParent.children["0"];
    if (srcObj.tagName == "IMG") {
        srcObj.setAttribute("src", srcObj.getAttribute("src").replace(regExp, ".svg"));
    }
}

Serializing an object as UTF-8 XML in .NET

Very good answer using inheritance, just remember to override the initializer

public class Utf8StringWriter : StringWriter
{
    public Utf8StringWriter(StringBuilder sb) : base (sb)
    {
    }
    public override Encoding Encoding { get { return Encoding.UTF8; } }
}

img onclick call to JavaScript function

Put the javascript part and the end right before the closing </body> then it should work.

http://jsfiddle.net/Q3Zy3/1/

  <img onclick="exportToForm('1.6','55','10','50','1');" src="China-Flag-256.png"/>
  <button onclick="exportToForm('1.6','55','10','50','1');" style="background-color: #00FFFF">Export</button>

  <script type="text/javascript">
      function exportToForm(a,b,c,d,e) {
      alert(a + b);
      window.external.values(a.value, b.value, c.value, d.value, e.value);
  }
</script>

downloading all the files in a directory with cURL

You can use script like this for mac:

for f in $(curl -s -l -u user:pass ftp://your_ftp_server_ip/folder/) 
 do curl -O -u user:pass ftp://your_ftp_server_ip/folder/$f 
done

Detect a finger swipe through JavaScript on the iPhone and Android

I had to write a simple script for a carousel to detect swipe left or right.

I utilised Pointer Events instead of Touch Events.

I hope this is useful to individuals and I welcome any insights to improve my code; I feel rather sheepish to join this thread with significantly superior JS developers.

function getSwipeX({elementId}) {

  this.e               = document.getElementsByClassName(elementId)[0];
  this.initialPosition = 0;
  this.lastPosition    = 0;
  this.threshold       = 200;
  this.diffInPosition  = null;
  this.diffVsThreshold = null;
  this.gestureState    = 0;

  this.getTouchStart = (event) => {
    event.preventDefault();
    if (window.PointerEvent) {
      this.e.setPointerCapture(event.pointerId);
    }
    return this.initalTouchPos = this.getGesturePoint(event);
  }

  this.getTouchMove  = (event) => {
    event.preventDefault();
    return this.lastPosition = this.getGesturePoint(event);
  }

  this.getTouchEnd   = (event) => {
    event.preventDefault();
    if (window.PointerEvent) {
      this.e.releasePointerCapture(event.pointerId);
    }
    this.doSomething();
    this.initialPosition = 0;
  }

  this.getGesturePoint = (event) => {
    this.point = event.pageX
    return this.point;
  }

  this.whatGestureDirection = (event) => {
    this.diffInPosition  = this.initalTouchPos - this.lastPosition;
    this.diffVsThreshold = Math.abs(this.diffInPosition) > this.threshold;
    (Math.sign(this.diffInPosition) > 0) ? this.gestureState = 'L' : (Math.sign(this.diffInPosition) < 0) ? this.gestureState = 'R' : this.gestureState = 'N';
    
    return [this.diffInPosition, this.diffVsThreshold, this.gestureState];
  }

  this.doSomething = (event) => {
    let [gestureDelta,gestureThreshold,gestureDirection] = this.whatGestureDirection();

    // USE THIS TO DEBUG
    console.log(gestureDelta,gestureThreshold,gestureDirection);

    if (gestureThreshold) {
      (gestureDirection == 'L') ? // LEFT ACTION : // RIGHT ACTION
    }
  }

  if (window.PointerEvent) {
    this.e.addEventListener('pointerdown', this.getTouchStart, true);
    this.e.addEventListener('pointermove', this.getTouchMove, true);
    this.e.addEventListener('pointerup', this.getTouchEnd, true);
    this.e.addEventListener('pointercancel', this.getTouchEnd, true);
  }
}

You can call the function using new.

window.addEventListener('load', () => {
  let test = new getSwipeX({
    elementId: 'your_div_here'
  });
})

Check if value exists in dataTable?

You can use Linq. Something like:

bool exists = dt.AsEnumerable().Where(c => c.Field<string>("Author").Equals("your lookup value")).Count() > 0;

PHP Excel Header

Try this

header("Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
header("Content-Disposition: attachment;filename=\"filename.xlsx\"");
header("Cache-Control: max-age=0");

How can I select records ONLY from yesterday?

trunc(tran_date) = trunc(sysdate -1)

Why is textarea filled with mysterious white spaces?

Well, everything between <textarea> and </textarea> is used as the default value for your textarea box. There is some whitespace in your example there. Try to eliminate all of that.

Paste in insert mode?

If you don't want Vim to mangle formatting in incoming pasted text, you might also want to consider using: :set paste. This will prevent Vim from re-tabbing your code. When done pasting, :set nopaste will return to the normal behavior.

It's also possible to toggle the mode with a single key, by adding something like set pastetoggle=<F2> to your .vimrc. More details on toggling auto-indent are here.

What is function overloading and overriding in php?

Strictly speaking, there's no difference, since you cannot do either :)

Function overriding could have been done with a PHP extension like APD, but it's deprecated and afaik last version was unusable.

Function overloading in PHP cannot be done due to dynamic typing, ie, in PHP you don't "define" variables to be a particular type. Example:

$a=1;
$a='1';
$a=true;
$a=doSomething();

Each variable is of a different type, yet you can know the type before execution (see the 4th one). As a comparison, other languages use:

int a=1;
String s="1";
bool a=true;
something a=doSomething();

In the last example, you must forcefully set the variable's type (as an example, I used data type "something").


Another "issue" why function overloading is not possible in PHP: PHP has a function called func_get_args(), which returns an array of current arguments, now consider the following code:

function hello($a){
  print_r(func_get_args());
}

function hello($a,$a){
  print_r(func_get_args());
}

hello('a');
hello('a','b');

Considering both functions accept any amount of arguments, which one should the compiler choose?


Finally, I'd like to point out why the above replies are partially wrong; function overloading/overriding is NOT equal to method overloading/overriding.

Where a method is like a function but specific to a class, in which case, PHP does allow overriding in classes, but again no overloading, due to language semantics.

To conclude, languages like Javascript allow overriding (but again, no overloading), however they may also show the difference between overriding a user function and a method:

/// Function Overriding ///

function a(){
   alert('a');
}
a=function(){
   alert('b');
}

a(); // shows popup with 'b'


/// Method Overriding ///

var a={
  "a":function(){
    alert('a');
  }
}
a.a=function(){
   alert('b');
}

a.a(); // shows popup with 'b'

Can I use Twitter Bootstrap and jQuery UI at the same time?

In my limited experience I am coming across issues as well. It appears that JQuery elements (such as buttons) can be styled using bootstrap CSS. However, I am experiencing issues having created a JQuery UI tab and wanting to lock a bootstrap only input (using the input-append class) to the bottom of each tab, only the first sits correctly. So, JQuery tabs + Bootstrap buttons = probably not.

Pandas conditional creation of a series/dataframe column

List comprehension is another way to create another column conditionally. If you are working with object dtypes in columns, like in your example, list comprehensions typically outperform most other methods.

Example list comprehension:

df['color'] = ['red' if x == 'Z' else 'green' for x in df['Set']]

%timeit tests:

import pandas as pd
import numpy as np

df = pd.DataFrame({'Type':list('ABBC'), 'Set':list('ZZXY')})
%timeit df['color'] = ['red' if x == 'Z' else 'green' for x in df['Set']]
%timeit df['color'] = np.where(df['Set']=='Z', 'green', 'red')
%timeit df['color'] = df.Set.map( lambda x: 'red' if x == 'Z' else 'green')

1000 loops, best of 3: 239 µs per loop
1000 loops, best of 3: 523 µs per loop
1000 loops, best of 3: 263 µs per loop

MySQL order by before group by

Just to recap, the standard solution uses an uncorrelated subquery and looks like this:

SELECT x.*
  FROM my_table x
  JOIN (SELECT grouping_criteria,MAX(ranking_criterion) max_n FROM my_table GROUP BY grouping_criteria) y
    ON y.grouping_criteria = x.grouping_criteria
   AND y.max_n = x.ranking_criterion;

If you're using an ancient version of MySQL, or a fairly small data set, then you can use the following method:

SELECT x.*
  FROM my_table x
  LEFT
  JOIN my_table y
    ON y.joining_criteria = x.joining_criteria
   AND y.ranking_criteria < x.ranking_criteria
 WHERE y.some_non_null_column IS NULL;  

Install MySQL on Ubuntu without a password prompt

This should do the trick

export DEBIAN_FRONTEND=noninteractive
sudo -E apt-get -q -y install mysql-server

Of course, it leaves you with a blank root password - so you'll want to run something like

mysqladmin -u root password mysecretpasswordgoeshere

Afterwards to add a password to the account.

Best way to check function arguments?

There are different ways to check what a variable is in Python. So, to list a few:

  • isinstance(obj, type) function takes your variable, obj and gives you True is it is the same type of the type you listed.

  • issubclass(obj, class) function that takes in a variable obj, and gives you True if obj is a subclass of class. So for example issubclass(Rabbit, Animal) would give you a True value

  • hasattr is another example, demonstrated by this function, super_len:


def super_len(o):
    if hasattr(o, '__len__'):
        return len(o)

    if hasattr(o, 'len'):
        return o.len

    if hasattr(o, 'fileno'):
        try:
            fileno = o.fileno()
        except io.UnsupportedOperation:
            pass
        else:
            return os.fstat(fileno).st_size

    if hasattr(o, 'getvalue'):
        # e.g. BytesIO, cStringIO.StringI
        return len(o.getvalue())

hasattr leans more towards duck-typing, and something that is usually more pythonic but that term is up opinionated.

Just as a note, assert statements are usually used in testing, otherwise, just use if/else statements.

MVC 4 Data Annotations "Display" Attribute

One of the benefits is you can use it in multiple views and have a consistent label text. It is also used by asp.net MVC scaffolding to generate the labels text and makes it easier to generate meaningful text

[Display(Name = "Wild and Crazy")]
public string WildAndCrazyProperty { get; set; }

"Wild and Crazy" shows up consistently wherever you use the property in your application.

Sometimes this is not flexible as you might want to change the text in some view. In that case, you will have to use custom markup like in your second example

How can I find out the current route in Rails?

Based on @AmNaN suggestion (more details):

class ApplicationController < ActionController::Base

 def current_controller?(names)
  names.include?(params[:controller]) unless params[:controller].blank? || false
 end

 helper_method :current_controller?

end

Now you can call it e.g. in a navigation layout for marking list items as active:

<ul class="nav nav-tabs">
  <li role="presentation" class="<%= current_controller?('items') ? 'active' : '' %>">
    <%= link_to user_items_path(current_user) do %>
      <i class="fa fa-cloud-upload"></i>
    <% end %>
  </li>
  <li role="presentation" class="<%= current_controller?('users') ? 'active' : '' %>">
    <%= link_to users_path do %>
      <i class="fa fa-newspaper-o"></i>
    <% end %>
  </li>
  <li role="presentation" class="<%= current_controller?('alerts') ? 'active' : '' %>">
    <%= link_to alerts_path do %>
      <i class="fa fa-bell-o"></i>
    <% end %>
  </li>
</ul>

For the users and alerts routes, current_page? would be enough:

 current_page?(users_path)
 current_page?(alerts_path)

But with nested routes and request for all actions of a controller (comparable with items), current_controller? was the better method for me:

 resources :users do 
  resources :items
 end

The first menu entry is that way active for the following routes:

   /users/x/items        #index
   /users/x/items/x      #show
   /users/x/items/new    #new
   /users/x/items/x/edit #edit

List of All Folders and Sub-folders

As well as find listed in other answers, better shells allow both recurvsive globs and filtering of glob matches, so in zsh for example...

ls -lad **/*(/)

...lists all directories while keeping all the "-l" details that you want, which you'd otherwise need to recreate using something like...

find . -type d -exec ls -ld {} \;

(not quite as easy as the other answers suggest)

The benefit of find is that it's more independent of the shell - more portable, even for system() calls from within a C/C++ program etc..

What is IllegalStateException?

Usually, IllegalStateException is used to indicate that "a method has been invoked at an illegal or inappropriate time." However, this doesn't look like a particularly typical use of it.

The code you've linked to shows that it can be thrown within that code at line 259 - but only after dumping a SQLException to standard output.

We can't tell what's wrong just from that exception - and better code would have used the original SQLException as a "cause" exception (or just let the original exception propagate up the stack) - but you should be able to see more details on standard output. Look at that information, and you should be able to see what caused the exception, and fix it.

What does it mean with bug report captured in android tablet?

It's because you have turned on USB debugging in Developer Options. You can create a bug report by holding the power + both volume up and down.

Edit: This is what the forums say:

By pressing Volume up + Volume down + power button, you will feel a vibration after a second or so, that's when the bug reporting initiated.

To disable:

/system/bin/bugmailer.sh must be deleted/renamed.

There should be a folder on your SD card called "bug reports".

Have a look at this thread: http://forum.xda-developers.com/showthread.php?t=2252948

And this one: http://forum.xda-developers.com/showthread.php?t=1405639

Difference between single and double quotes in Bash

If you're referring to what happens when you echo something, the single quotes will literally echo what you have between them, while the double quotes will evaluate variables between them and output the value of the variable.

For example, this

#!/bin/sh
MYVAR=sometext
echo "double quotes gives you $MYVAR"
echo 'single quotes gives you $MYVAR'

will give this:

double quotes gives you sometext
single quotes gives you $MYVAR

Passing multiple parameters to pool.map() function in Python

You could use a map function that allows multiple arguments, as does the fork of multiprocessing found in pathos.

>>> from pathos.multiprocessing import ProcessingPool as Pool
>>> 
>>> def add_and_subtract(x,y):
...   return x+y, x-y
... 
>>> res = Pool().map(add_and_subtract, range(0,20,2), range(-5,5,1))
>>> res
[(-5, 5), (-2, 6), (1, 7), (4, 8), (7, 9), (10, 10), (13, 11), (16, 12), (19, 13), (22, 14)]
>>> Pool().map(add_and_subtract, *zip(*res))
[(0, -10), (4, -8), (8, -6), (12, -4), (16, -2), (20, 0), (24, 2), (28, 4), (32, 6), (36, 8)]

pathos enables you to easily nest hierarchical parallel maps with multiple inputs, so we can extend our example to demonstrate that.

>>> from pathos.multiprocessing import ThreadingPool as TPool
>>> 
>>> res = TPool().amap(add_and_subtract, *zip(*Pool().map(add_and_subtract, range(0,20,2), range(-5,5,1))))
>>> res.get()
[(0, -10), (4, -8), (8, -6), (12, -4), (16, -2), (20, 0), (24, 2), (28, 4), (32, 6), (36, 8)]

Even more fun, is to build a nested function that we can pass into the Pool. This is possible because pathos uses dill, which can serialize almost anything in python.

>>> def build_fun_things(f, g):
...   def do_fun_things(x, y):
...     return f(x,y), g(x,y)
...   return do_fun_things
... 
>>> def add(x,y):
...   return x+y
... 
>>> def sub(x,y):
...   return x-y
... 
>>> neato = build_fun_things(add, sub)
>>> 
>>> res = TPool().imap(neato, *zip(*Pool().map(neato, range(0,20,2), range(-5,5,1))))
>>> list(res)
[(0, -10), (4, -8), (8, -6), (12, -4), (16, -2), (20, 0), (24, 2), (28, 4), (32, 6), (36, 8)]

If you are not able to go outside of the standard library, however, you will have to do this another way. Your best bet in that case is to use multiprocessing.starmap as seen here: Python multiprocessing pool.map for multiple arguments (noted by @Roberto in the comments on the OP's post)

Get pathos here: https://github.com/uqfoundation

How to create Windows EventLog source from command line?

You can also use Windows PowerShell with the following command:

if ([System.Diagnostics.EventLog]::SourceExists($source) -eq $false) {
    [System.Diagnostics.EventLog]::CreateEventSource($source, "Application")
}

Make sure to check that the source does not exist before calling CreateEventSource, otherwise it will throw an exception.

For more info:

Optional query string parameters in ASP.NET Web API

if you want to pass multiple parameters then you can create model instead of passing multiple parameters.

in case you dont want to pass any parameter then you can skip as well in it, and your code will look neat and clean.

findAll() in yii

Use the below code. This should work.

$comments = EmailArchive::find()->where(['email_id' => $id])->all();

CSS rule to apply only if element has BOTH classes

div.abc.xyz {
    /* rules go here */
}

... or simply:

.abc.xyz {
    /* rules go here */
}

How to obtain the last index of a list?

len(list1)-1 is definitely the way to go, but if you absolutely need a list that has a function that returns the last index, you could create a class that inherits from list.

class MyList(list):
    def last_index(self):
        return len(self)-1


>>> l=MyList([1, 2, 33, 51])
>>> l.last_index()
3

How can I multiply all items in a list together with Python?

How about using recursion?

def multiply(lst):
    if len(lst) > 1:
        return multiply(lst[:-1])* lst[-1]
    else:
        return lst[0]

Adding Only Untracked Files

If you have thousands of untracked files (ugh, don't ask) then git add -i will not work when adding *. You will get an error stating Argument list too long.

If you then also are on Windows (don't ask #2 :-) and need to use PowerShell for adding all untracked files, you can use this command:

git ls-files -o --exclude-standard | select | foreach { git add $_ }

How to check if a String contains any of some strings

public static bool ContainsAny(this string haystack, IEnumerable<string> needles)
{
    return needles.Any(haystack.Contains);
}

HTML5 File API read as text and binary

Note in 2018: readAsBinaryString is outdated. For use cases where previously you'd have used it, these days you'd use readAsArrayBuffer (or in some cases, readAsDataURL) instead.


readAsBinaryString says that the data must be represented as a binary string, where:

...every byte is represented by an integer in the range [0..255].

JavaScript originally didn't have a "binary" type (until ECMAScript 5's WebGL support of Typed Array* (details below) -- it has been superseded by ECMAScript 2015's ArrayBuffer) and so they went with a String with the guarantee that no character stored in the String would be outside the range 0..255. (They could have gone with an array of Numbers instead, but they didn't; perhaps large Strings are more memory-efficient than large arrays of Numbers, since Numbers are floating-point.)

If you're reading a file that's mostly text in a western script (mostly English, for instance), then that string is going to look a lot like text. If you read a file with Unicode characters in it, you should notice a difference, since JavaScript strings are UTF-16** (details below) and so some characters will have values above 255, whereas a "binary string" according to the File API spec wouldn't have any values above 255 (you'd have two individual "characters" for the two bytes of the Unicode code point).

If you're reading a file that's not text at all (an image, perhaps), you'll probably still get a very similar result between readAsText and readAsBinaryString, but with readAsBinaryString you know that there won't be any attempt to interpret multi-byte sequences as characters. You don't know that if you use readAsText, because readAsText will use an encoding determination to try to figure out what the file's encoding is and then map it to JavaScript's UTF-16 strings.

You can see the effect if you create a file and store it in something other than ASCII or UTF-8. (In Windows you can do this via Notepad; the "Save As" as an encoding drop-down with "Unicode" on it, by which looking at the data they seem to mean UTF-16; I'm sure Mac OS and *nix editors have a similar feature.) Here's a page that dumps the result of reading a file both ways:

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-type" content="text/html;charset=UTF-8">
<title>Show File Data</title>
<style type='text/css'>
body {
    font-family: sans-serif;
}
</style>
<script type='text/javascript'>

    function loadFile() {
        var input, file, fr;

        if (typeof window.FileReader !== 'function') {
            bodyAppend("p", "The file API isn't supported on this browser yet.");
            return;
        }

        input = document.getElementById('fileinput');
        if (!input) {
            bodyAppend("p", "Um, couldn't find the fileinput element.");
        }
        else if (!input.files) {
            bodyAppend("p", "This browser doesn't seem to support the `files` property of file inputs.");
        }
        else if (!input.files[0]) {
            bodyAppend("p", "Please select a file before clicking 'Load'");
        }
        else {
            file = input.files[0];
            fr = new FileReader();
            fr.onload = receivedText;
            fr.readAsText(file);
        }

        function receivedText() {
            showResult(fr, "Text");

            fr = new FileReader();
            fr.onload = receivedBinary;
            fr.readAsBinaryString(file);
        }

        function receivedBinary() {
            showResult(fr, "Binary");
        }
    }

    function showResult(fr, label) {
        var markup, result, n, aByte, byteStr;

        markup = [];
        result = fr.result;
        for (n = 0; n < result.length; ++n) {
            aByte = result.charCodeAt(n);
            byteStr = aByte.toString(16);
            if (byteStr.length < 2) {
                byteStr = "0" + byteStr;
            }
            markup.push(byteStr);
        }
        bodyAppend("p", label + " (" + result.length + "):");
        bodyAppend("pre", markup.join(" "));
    }

    function bodyAppend(tagName, innerHTML) {
        var elm;

        elm = document.createElement(tagName);
        elm.innerHTML = innerHTML;
        document.body.appendChild(elm);
    }

</script>
</head>
<body>
<form action='#' onsubmit="return false;">
<input type='file' id='fileinput'>
<input type='button' id='btnLoad' value='Load' onclick='loadFile();'>
</form>
</body>
</html>

If I use that with a "Testing 1 2 3" file stored in UTF-16, here are the results I get:

Text (13):

54 65 73 74 69 6e 67 20 31 20 32 20 33

Binary (28):

ff fe 54 00 65 00 73 00 74 00 69 00 6e 00 67 00 20 00 31 00 20 00 32 00 20 00 33 00

As you can see, readAsText interpreted the characters and so I got 13 (the length of "Testing 1 2 3"), and readAsBinaryString didn't, and so I got 28 (the two-byte BOM plus two bytes for each character).


* XMLHttpRequest.response with responseType = "arraybuffer" is supported in HTML 5.

** "JavaScript strings are UTF-16" may seem like an odd statement; aren't they just Unicode? No, a JavaScript string is a series of UTF-16 code units; you see surrogate pairs as two individual JavaScript "characters" even though, in fact, the surrogate pair as a whole is just one character. See the link for details.

What is the basic difference between the Factory and Abstract Factory Design Patterns?

Basic difference:

Factory: Creates objects without exposing the instantiation logic to the client.

Factory Method: Define an interface for creating an object, but let the subclasses decide which class to instantiate. The Factory method lets a class defer instantiation to subclasses

Abstract Factory: Provides an interface for creating families of related or dependent objects without specifying their concrete classes.

AbstractFactory pattern uses composition to delegate responsibility of creating object to another class while Factory method pattern uses inheritance and relies on derived class or sub class to create object

From oodesign articles:

Factory class diagram:

enter image description here

Example: StaticFactory

 public class ShapeFactory {

   //use getShape method to get object of type shape 
   public static Shape getShape(String shapeType){
      if(shapeType == null){
         return null;
      }     
      if(shapeType.equalsIgnoreCase("CIRCLE")){
         return new Circle();

      } else if(shapeType.equalsIgnoreCase("RECTANGLE")){
         return new Rectangle();

      } else if(shapeType.equalsIgnoreCase("SQUARE")){
         return new Square();
      }

      return null;
   }
}

Non-Static Factory implementing FactoryMethod example is available in this post:

Design Patterns: Factory vs Factory method vs Abstract Factory

When to use: Client just need a class and does not care about which concrete implementation it is getting.

Factory Method class digaram:

enter image description here

When to use: Client doesn't know what concrete classes it will be required to create at runtime, but just wants to get a class that will do the job.

Abstract Factory class diagram from dzone

enter image description here

When to use: When your system has to create multiple families of products or you want to provide a library of products without exposing the implementation details.

Source code examples in above articles are very good to understand the concepts clearly.

Related SE question with code example:

Factory Pattern. When to use factory methods?

Differences:

  1. Abstract Factory classes are often implemented with Factory Methods, but they can also be implemented using Prototype
  2. Designs start out using Factory Method (less complicated, more customizable, subclasses proliferate) and evolve toward other creational patterns (more flexible, more complex) where more flexibility is needed.
  3. Factory Methods are usually called within Template Methods.

Other useful articles:

factory_method from sourcemaking

abstract_factory from sourcemaking

abstract-factory-design-pattern from journaldev

How to access accelerometer/gyroscope data from Javascript?

There are currently three distinct events which may or may not be triggered when the client devices moves. Two of them are focused around orientation and the last on motion:

  • ondeviceorientation is known to work on the desktop version of Chrome, and most Apple laptops seems to have the hardware required for this to work. It also works on Mobile Safari on the iPhone 4 with iOS 4.2. In the event handler function, you can access alpha, beta, gamma values on the event data supplied as the only argument to the function.

  • onmozorientation is supported on Firefox 3.6 and newer. Again, this is known to work on most Apple laptops, but might work on Windows or Linux machines with accelerometer as well. In the event handler function, look for x, y, z fields on the event data supplied as first argument.

  • ondevicemotion is known to work on iPhone 3GS + 4 and iPad (both with iOS 4.2), and provides data related to the current acceleration of the client device. The event data passed to the handler function has acceleration and accelerationIncludingGravity, which both have three fields for each axis: x, y, z

The "earthquake detecting" sample website uses a series of if statements to figure out which event to attach to (in a somewhat prioritized order) and passes the data received to a common tilt function:

if (window.DeviceOrientationEvent) {
    window.addEventListener("deviceorientation", function () {
        tilt([event.beta, event.gamma]);
    }, true);
} else if (window.DeviceMotionEvent) {
    window.addEventListener('devicemotion', function () {
        tilt([event.acceleration.x * 2, event.acceleration.y * 2]);
    }, true);
} else {
    window.addEventListener("MozOrientation", function () {
        tilt([orientation.x * 50, orientation.y * 50]);
    }, true);
}

The constant factors 2 and 50 are used to "align" the readings from the two latter events with those from the first, but these are by no means precise representations. For this simple "toy" project it works just fine, but if you need to use the data for something slightly more serious, you will have to get familiar with the units of the values provided in the different events and treat them with respect :)

Ansible: Set variable to file content

You can use fetch module to copy files from remote hosts to local, and lookup module to read the content of fetched files.

SQL UPDATE with sub-query that references the same table in MySQL

UPDATE user_account student, (
   SELECT teacher.education_facility_id as teacherid
   FROM user_account teacher
   WHERE teacher.user_account_id = student.teacher_id AND teacher.user_type = 'ROLE_TEACHER'
) teach SET student.student_education_facility_id= teach.teacherid WHERE student.user_type = 'ROLE_STUDENT';

How to ignore parent css style

It would make sense for CSS to have a way to simply add an additional style (in the head section of your page, for example, which would override the linked style sheet) such as this:

<head>
<style>
#elementId select {
    /* turn all styles off (no way to do this) */
}
</style>
</head>

and turn off all previously applied styles, but there is no way to do this. You will have to override the height attribute and set it to a new value in the head section of your pages.

<head>
<style>
#elementId select {
    height:1.5em;
}
</style>
</head>

tsql returning a table from a function or store procedure

You don't need (shouldn't use) a function as far as I can tell. The stored procedure will return tabular data from any SELECT statements you include that return tabular data.

A stored proc does not use RETURN statements.

 CREATE PROCEDURE name
 AS

 SELECT stuff INTO #temptbl1

 .......


 SELECT columns FROM #temptbln

How can I delete derived data in Xcode 8?

Steps For Delete DerivedData:

  1. Open Finder
  2. From menu click on Go > Go to Folder
  3. Enter ~/Library/Developer/Xcode/DerivedData in textfield
  4. Click on Go button
  5. You will see the folders of your Xcode projects
  6. Delete the folders of projects, which you don't need.

vertical align middle in <div>

You can use Line height a big as height of the div. But for me best solution is this --> position:relative; top:50%; transform:translate(0,50%);

Regex allow digits and a single dot

If you want to allow 1 and 1.2:

(?<=^| )\d+(\.\d+)?(?=$| )

If you want to allow 1, 1.2 and .1:

(?<=^| )\d+(\.\d+)?(?=$| )|(?<=^| )\.\d+(?=$| )

If you want to only allow 1.2 (only floats):

(?<=^| )\d+\.\d+(?=$| )

\d allows digits (while \D allows anything but digits).

(?<=^| ) checks that the number is preceded by either a space or the beginning of the string. (?=$| ) makes sure the string is followed by a space or the end of the string. This makes sure the number isn't part of another number or in the middle of words or anything.

Edit: added more options, improved the regexes by adding lookahead- and behinds for making sure the numbers are standalone (i.e. aren't in the middle of words or other numbers.

How do I call a Django function on button click?

here is a pure-javascript, minimalistic approach. I use JQuery but you can use any library (or even no libraries at all).

<html>
    <head>
        <title>An example</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
        <script>
            function call_counter(url, pk) {
                window.open(url);
                $.get('YOUR_VIEW_HERE/'+pk+'/', function (data) {
                    alert("counter updated!");
                });
            }
        </script>
    </head>
    <body>
        <button onclick="call_counter('http://www.google.com', 12345);">
            I update object 12345
        </button>
        <button onclick="call_counter('http://www.yahoo.com', 999);">
            I update object 999
        </button>
    </body>
</html>

Alternative approach

Instead of placing the JavaScript code, you can change your link in this way:

<a target="_blank" 
    class="btn btn-info pull-right" 
    href="{% url YOUR_VIEW column_3_item.pk %}/?next={{column_3_item.link_for_item|urlencode:''}}">
    Check It Out
</a>

and in your views.py:

def YOUR_VIEW_DEF(request, pk):
    YOUR_OBJECT.objects.filter(pk=pk).update(views=F('views')+1)
    return HttpResponseRedirect(request.GET.get('next')))

How do I write a "tab" in Python?

You can use \t in a string literal:

"hello\talex"

MySQL root password change

  1. On Mac open system preferences> MySQL.
  2. In the configuration section of MySQL check for initialize database.
  3. change the password in the prompt. initialize Database

How to debug ORA-01775: looping chain of synonyms?

http://ora-01775.ora-code.com/ suggests:

ORA-01775: looping chain of synonyms
Cause: Through a series of CREATE synonym statements, a synonym was defined that referred to itself. For example, the following definitions are circular:
CREATE SYNONYM s1 for s2 CREATE SYNONYM s2 for s3 CREATE SYNONYM s3 for s1
Action: Change one synonym definition so that it applies to a base table or view and retry the operation.

How do I start a program with arguments when debugging?

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

Launchsettings.json

enter image description here

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

see "Application Arguments:"

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

enter image description here

How to round up with excel VBA round()?

I got a workaround myself:

    'G = Maximum amount of characters for width of comment cell
    G = 100
    'CommentX
    If THISWB.Sheets("Source").Cells(i, CommentColumn).Value = "" Then
        CommentX = ""
     Else
        CommentArray = Split(THISWB.Sheets("Source").Cells(i, CommentColumn).Value, Chr(10)) 'splits on alt + enter
        DeliverableComment = "Available"
    End If
                        If CommentX <> "" Then

                            'this loops for each newline in a cell (alt+enter in cell)
                            For CommentPart = 0 To UBound(CommentArray)
                            'format comment to max G characters long
                                LASTSPACE = 0
                                LASTSPACE2 = 0
                                    If Len(CommentArray(CommentPart)) > G Then

                                        'find last space in G length character string to make sure the line ends with a whole word and the new line starts with a whole word
                                        Do Until LASTSPACE2 >= Len(CommentArray(CommentPart))
                                            If CommentPart = 0 And LASTSPACE2 = 0 And LASTSPACE = 0 Then
                                                LASTSPACE = WorksheetFunction.Find("þ", WorksheetFunction.Substitute(Left(CommentArray(CommentPart), G), " ", "þ", (Len(Left(CommentArray(CommentPart), G)) - Len(WorksheetFunction.Substitute(Left(CommentArray(CommentPart), G), " ", "")))))
                                                ActiveCell.AddComment Left(CommentArray(CommentPart), LASTSPACE)
                                            Else
                                                If LASTSPACE2 = 0 Then
                                                   LASTSPACE = WorksheetFunction.Find("þ", WorksheetFunction.Substitute(Left(CommentArray(CommentPart), G), " ", "þ", (Len(Left(CommentArray(CommentPart), G)) - Len(WorksheetFunction.Substitute(Left(CommentArray(CommentPart), G), " ", "")))))
                                                   ActiveCell.Comment.Text Text:=ActiveCell.Comment.Text & vbNewLine & Left(CommentArray(CommentPart), LASTSPACE)
                                                Else
                                                   If Len(Mid(CommentArray(CommentPart), LASTSPACE2)) < G Then
                                                       LASTSPACE = Len(Mid(CommentArray(CommentPart), LASTSPACE2))
                                                       ActiveCell.Comment.Text Text:=ActiveCell.Comment.Text & vbNewLine & Mid(CommentArray(CommentPart), LASTSPACE2 - 1, LASTSPACE)
                                                   Else
                                                       LASTSPACE = WorksheetFunction.Find("þ", WorksheetFunction.Substitute(Mid(CommentArray(CommentPart), LASTSPACE2, G), " ", "þ", (Len(Mid(CommentArray(CommentPart), LASTSPACE2, G)) - Len(WorksheetFunction.Substitute(Mid(CommentArray(CommentPart), LASTSPACE2, G), " ", "")))))
                                                       ActiveCell.Comment.Text Text:=ActiveCell.Comment.Text & vbNewLine & Mid(CommentArray(CommentPart), LASTSPACE2 - 1, LASTSPACE)
                                                   End If
                                                End If
                                            End If
                                            LASTSPACE2 = LASTSPACE + LASTSPACE2 + 1
                                        Loop
                                    Else
                                        If CommentPart = 0 And LASTSPACE2 = 0 And LASTSPACE = 0 Then
                                          ActiveCell.AddComment CommentArray(CommentPart)
                                        Else
                                          ActiveCell.Comment.Text Text:=ActiveCell.Comment.Text & vbNewLine & CommentArray(CommentPart)
                                        End If
                                    End If

                            Next CommentPart
                            ActiveCell.Comment.Shape.TextFrame.AutoSize = True

                        End If

Feel free to thank me. Works like a charm to me and the autosize function also works!

Centering floating divs within another div

In my case, I could not get the answer by @Sampson to work for me, at best I got a single column centered on the page. In the process however, I learned how the float actually works and created this solution. At it's core the fix is very simple but hard to find as evident by this thread which has had more than 146k views at the time of this post without mention.

All that is needed is to total the amount of screen space width that the desired layout will occupy then make the parent the same width and apply margin:auto. That's it!

The elements in the layout will dictate the width and height of the "outer" div. Take each "myFloat" or element's width or height + its borders + its margins and its paddings and add them all together. Then add the other elements together in the same fashion. This will give you the parent width. They can all be somewhat different sizes and you can do this with fewer or more elements.

Ex.(each element has 2 sides so border, margin and padding get multiplied x2)

So an element that has a width of 10px, border 2px, margin 6px, padding 3px would look like this: 10 + 4 + 12 + 6 = 32

Then add all of your element's totaled widths together.

Element 1 = 32
Element 2 = 24
Element 3 = 32
Element 4 = 24

In this example the width for the "outer" div would be 112.

_x000D_
_x000D_
.outer {_x000D_
  /* floats + margins + borders = 270 */_x000D_
  max-width: 270px;_x000D_
  margin: auto;_x000D_
  height: 80px;_x000D_
  border: 1px;_x000D_
  border-style: solid;_x000D_
}_x000D_
_x000D_
.myFloat {_x000D_
    /* 3 floats x 50px = 150px */_x000D_
    width: 50px;_x000D_
    /* 6 margins x 10px = 60 */_x000D_
    margin: 10px;_x000D_
    /* 6 borders x 10px = 60 */_x000D_
    border: 10px solid #6B6B6B;_x000D_
    float: left;_x000D_
    text-align: center;_x000D_
    height: 40px;_x000D_
}
_x000D_
<div class="outer">_x000D_
  <div class="myFloat">Float 1</div>_x000D_
  <div class="myFloat">Float 2</div>_x000D_
  <div class="myFloat">Float 3</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

git repo says it's up-to-date after pull but files are not updated

For me my forked branch was not in sync with the master branch. So I went to bitbucket and synced and merged my forked branch and then tried to take the pull. Then it worked fine.

HTML code for INR

The indian rupee sign is pretty new (introduced this July if I read it correctly) and doesn't even have a Unicode position yet, much less a HTML entity.

Even when it gets a Unicode position, it will probably still take years until it can be reliably used on a web page, because the client computers' Fonts will need to be updated accordingly. (I could imagine a font-face workaround with a custom font, though.)

Wikipedia uses an image file to display the symbol. It's far from good, but it may be the best workaround at the moment.

The generic rupee sign has three Unicode characters. See here.

AJAX cross domain call

Unfortunately (or fortunately) not. The cross-domain policy is there for a reason, if it were easy to get around it then it wouldn't be very effective as a security measure. Other than JSONP, the only option is to proxy the pages using your own server.

With an iframe, they are subject to the same policy. Of course you can display the data from an external domain, you just can't manipulate it.

How to convert numpy arrays to standard TensorFlow format?

You can use tf.pack (tf.stack in TensorFlow 1.0.0) method for this purpose. Here is how to pack a random image of type numpy.ndarray into a Tensor:

import numpy as np
import tensorflow as tf
random_image = np.random.randint(0,256, (300,400,3))
random_image_tensor = tf.pack(random_image)
tf.InteractiveSession()
evaluated_tensor = random_image_tensor.eval()

UPDATE: to convert a Python object to a Tensor you can use tf.convert_to_tensor function.

C++ preprocessor __VA_ARGS__ number of arguments

With msvc extension:

#define Y_TUPLE_SIZE(...) Y_TUPLE_SIZE_II((Y_TUPLE_SIZE_PREFIX_ ## __VA_ARGS__ ## _Y_TUPLE_SIZE_POSTFIX,32,31,30,29,28,27,26,25,24,23,22,21,20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0))
#define Y_TUPLE_SIZE_II(__args) Y_TUPLE_SIZE_I __args

#define Y_TUPLE_SIZE_PREFIX__Y_TUPLE_SIZE_POSTFIX ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,0

#define Y_TUPLE_SIZE_I(__p0,__p1,__p2,__p3,__p4,__p5,__p6,__p7,__p8,__p9,__p10,__p11,__p12,__p13,__p14,__p15,__p16,__p17,__p18,__p19,__p20,__p21,__p22,__p23,__p24,__p25,__p26,__p27,__p28,__p29,__p30,__p31,__n,...) __n

Works for 0 - 32 arguments. This limit can be easily extended.

EDIT: Simplified version (works in VS2015 14.0.25431.01 Update 3 & gcc 7.4.0) up to 100 arguments to copy & paste:

#define COUNTOF(...) _COUNTOF_CAT( _COUNTOF_A, ( 0, ##__VA_ARGS__, 100,\
    99, 98, 97, 96, 95, 94, 93, 92, 91, 90,\
    89, 88, 87, 86, 85, 84, 83, 82, 81, 80,\
    79, 78, 77, 76, 75, 74, 73, 72, 71, 70,\
    69, 68, 67, 66, 65, 64, 63, 62, 61, 60,\
    59, 58, 57, 56, 55, 54, 53, 52, 51, 50,\
    49, 48, 47, 46, 45, 44, 43, 42, 41, 40,\
    39, 38, 37, 36, 35, 34, 33, 32, 31, 30,\
    29, 28, 27, 26, 25, 24, 23, 22, 21, 20,\
    19, 18, 17, 16, 15, 14, 13, 12, 11, 10,\
    9, 8, 7, 6, 5, 4, 3, 2, 1, 0 ) )
#define _COUNTOF_CAT( a, b ) a b
#define _COUNTOF_A( a0, a1, a2, a3, a4, a5, a6, a7, a8, a9,\
    a10, a11, a12, a13, a14, a15, a16, a17, a18, a19,\
    a20, a21, a22, a23, a24, a25, a26, a27, a28, a29,\
    a30, a31, a32, a33, a34, a35, a36, a37, a38, a39,\
    a40, a41, a42, a43, a44, a45, a46, a47, a48, a49,\
    a50, a51, a52, a53, a54, a55, a56, a57, a58, a59,\
    a60, a61, a62, a63, a64, a65, a66, a67, a68, a69,\
    a70, a71, a72, a73, a74, a75, a76, a77, a78, a79,\
    a80, a81, a82, a83, a84, a85, a86, a87, a88, a89,\
    a90, a91, a92, a93, a94, a95, a96, a97, a98, a99,\
    a100, n, ... ) n

How can I sharpen an image in OpenCV?

Try with this:

cv::bilateralFilter(img, 9, 75, 75);

You might find more information here.

How to Convert a Text File into a List in Python

Maybe:

crimefile = open(fileName, 'r')
yourResult = [line.split(',') for line in crimefile.readlines()]

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

There are two ways I usually do this, both use ssh:

scp -r sourcedir/ [email protected]:/dest/dir/

or, the more robust and faster (in terms of transfer speed) method:

rsync -auv -e ssh --progress sourcedir/ [email protected]:/dest/dir/

Read the man pages for each command if you want more details about how they work.

convert HTML ( having Javascript ) to PDF using JavaScript

Check this out http://www.techumber.com/2015/04/html-to-pdf-conversion-using-javascript.html

Basically you need to use html2canvas and jspdf to make it work. First you will convert your dom to image and then you will use jspdf to create pdf with the images.

EDIT: A short note on how it work. We will use two libraries to make this job done. http://html2canvas.hertzen.com/ and https://github.com/MrRio/jsPDF First we will create a dom image by using html2canvas them we will use jspdf addImage method to add that image to pdf. It seems simple but there are few bugs in jsPdf and html2cavas so you may need to change dom style temporarily. Hope this helps.

Server.MapPath - Physical path given, virtual path expected

if you already know your folder is: E:\ftproot\sales then you do not need to use Server.MapPath, this last one is needed if you only have a relative virtual path like ~/folder/folder1 and you want to know the real path in the disk...

Best Practice to Organize Javascript Library & CSS Folder Structure

 root/
   assets/
      lib/-------------------------libraries--------------------
          bootstrap/--------------Libraries can have js/css/images------------
              css/
              js/
              images/  
          jquery/
              js/
          font-awesome/
              css/
              images/
     common/--------------------common section will have application level resources             
          css/
          js/
          img/

 index.html

This is how I organized my application's static resources.

Getting Python error "from: can't read /var/mail/Bio"

Put this at the top of your .py file (for python 2.x)

#!/usr/bin/env python 

or for python 3.x

#!/usr/bin/env python3

This should look up the python environment, without it, it will execute the code as if it were not python code, but straight to the CLI. If you need to specify a manual location of python environment put

#!/#path/#to/#python

Error in launching AVD with AMD processor

If you're running Mac, as @pedro mentions ensure you have the HAXM installer dowloaded via the Android SDK Manager.

Next install it! In finder navigate to /YOUR_SDK_PATH/extras/intel/Hardware_Accelerated_Execution_Manager/

Run and install the .mpgk in the following .dmg

  • Yosemite: IntelHAXM_1.1.0_for_10.10.dmg
  • Pre-yosemite: IntelHAXM_1.1.0_below_10.10.dmg
  • El Capitan: IntelHAXM_6.0.1.dmg - please install the IntelHAXM_6.0.1.mpgk file within - it will ask you if you want to reinstall it. Just say yes.

Example:

$cd /YOUR_SDK_PATH/extras/intel/Hardware_Accelerated_Execution_Manager/
$open IntelHAXM_1.1.0_below_10.10.dmg

Sorted array list in Java

You can try Guava's TreeMultiSet.

 Multiset<Integer> ms=TreeMultiset.create(Arrays.asList(1,2,3,1,1,-1,2,4,5,100));
 System.out.println(ms);

How do I find the location of Python module sources?

Another way to check if you have multiple python versions installed, from the terminal.

-MBP:~python3 -m pip show pyperclip

Location: /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-

MBP:~ python -m pip show pyperclip

Location: /Users/umeshvuyyuru/Library/Python/2.7/lib/python/site-packages

SQL query for extracting year from a date

SELECT date_column_name FROM table_name WHERE EXTRACT(YEAR FROM date_column_name) = 2020

c# - approach for saving user settings in a WPF application?

Apart from a database, you can also have following options to save user related settings

  1. registry under HKEY_CURRENT_USER

  2. in a file in AppData folder

  3. using Settings file in WPF and by setting its scope as User

How to convert string into float in JavaScript?

Replace the comma with a dot.

This will only return 554:

var value = parseFloat("554,20")

This will return 554.20:

var value = parseFloat("554.20")

So in the end, you can simply use:

var fValue = parseFloat(document.getElementById("textfield").value.replace(",","."))

Don't forget that parseInt() should only be used to parse integers (no floating points). In your case it will only return 554. Additionally, calling parseInt() on a float will not round the number: it will take its floor (closest lower integer).


Extended example to answer Pedro Ferreira's question from the comments:

If the textfield contains thousands separator dots like in 1.234.567,99 those could be eliminated beforehand with another replace:

var fValue = parseFloat(document.getElementById("textfield").value.replace(/\./g,"").replace(",","."))

How to open a WPF Popup when another control is clicked, using XAML markup only?

The following uses EventTrigger to show the Popup. This means we don't need a ToggleButton for state binding. In this example the Click event of a Button is used. You can adapt it to use another element/event combination.

<Button x:Name="OpenPopup">Popup
    <Button.Triggers>
        <EventTrigger RoutedEvent="Button.Click">
            <EventTrigger.Actions>
                <BeginStoryboard>
                    <Storyboard>
                        <BooleanAnimationUsingKeyFrames 
                                 Storyboard.TargetName="ContextPopup" 
                                 Storyboard.TargetProperty="IsOpen">
                            <DiscreteBooleanKeyFrame KeyTime="0:0:0" Value="True" />
                        </BooleanAnimationUsingKeyFrames>
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger.Actions>
        </EventTrigger>
    </Button.Triggers>
</Button>
<Popup x:Name="ContextPopup"
       PlacementTarget="{Binding ElementName=OpenPopup}"
       StaysOpen="False">
    <Label>Popupcontent...</Label>
</Popup>

Please note that the Popup is referencing the Button by name and vice versa. So x:Name="..." is required on both, the Popup and the Button.

It can actually be further simplified by replacing the Storyboard stuff with a custom SetProperty EventTrigger Action described in this SO Answer

Auto start node.js server on boot

Here is another solution I wrote in C# to auto startup native node server or pm2 server on Windows.

Getting the location from an IP address

You can also use "smart-ip" service:

$.getJSON("http://smart-ip.net/geoip-json?callback=?",
    function (data) {
        alert(data.countryName);
        alert(data.city);
    }
);

Batch file include external file for variables

The best option according to me is to have key/value pairs file as it could be read from other scripting languages.

Other thing is I would prefer to have an option for comments in the values file - which can be easy achieved with eol option in for /f command.

Here's the example

values file:

;;;;;; file with example values ;;;;;;;;

;; Will be processed by a .bat file
;; ';' can be used for commenting a line

First_Value=value001

;;Do not let spaces arround the equal sign
;; As this makes the processing much easier
;; and reliable

Second_Value=%First_Value%_test

;;as call set will be used in reading script
;; refering another variables will be possible.

Third_Value=Something

;;; end

Reading script:

@echo off

:::::::::::::::::::::::::::::
set "VALUES_FILE=E:\scripts\example.values"
:::::::::::::::::::::::::::::

FOR /F "usebackq eol=; tokens=* delims=" %%# in (
    "%VALUES_FILE%"
) do (
    call set "%%#"
)

echo %First_Value% -- %Second_Value% -- %Third_Value%

How do I do pagination in ASP.NET MVC?

I had the same problem and found a very elegant solution for a Pager Class from

http://blogs.taiga.nl/martijn/2008/08/27/paging-with-aspnet-mvc/

In your controller the call looks like:

return View(partnerList.ToPagedList(currentPageIndex, pageSize));

and in your view:

<div class="pager">
    Seite: <%= Html.Pager(ViewData.Model.PageSize, 
                          ViewData.Model.PageNumber,
                          ViewData.Model.TotalItemCount)%>
</div>

Mean Squared Error in Numpy?

Just for kicks

mse = (np.linalg.norm(A-B)**2)/len(A)

Is there a way to return a list of all the image file names from a folder using only Javascript?

This will list all jpg files in the folder you define under url: and append them to a div as a paragraph. Can do it with ul li as well.

$.ajax({
  url: "YOUR FOLDER",
  success: function(data){
     $(data).find("a:contains(.jpg)").each(function(){
        // will loop through 
        var images = $(this).attr("href");

        $('<p></p>').html(images).appendTo('a div of your choice')

     });
  }
});

Objective C - Assign, Copy, Retain

Updated Answer for Changed Documentation

The information is now spread across several guides in the documentation. Here's a list of required reading:

The answer to this question now depends entirely on whether you're using an ARC-managed application (the modern default for new projects) or forcing manual memory management.

Assign vs. Weak - Use assign to set a property's pointer to the address of the object without retaining it or otherwise curating it; use weak to have the property point to nil automatically if the object assigned to it is deallocated. In most cases you'll want to use weak so you're not trying to access a deallocated object (illegal access of a memory address - "EXC_BAD_ACCESS") if you don't perform proper cleanup.

Retain vs. Copy - Declared properties use retain by default (so you can simply omit it altogether) and will manage the object's reference count automatically whether another object is assigned to the property or it's set to nil; Use copy to automatically send the newly-assigned object a -copy message (which will create a copy of the passed object and assign that copy to the property instead - useful (even required) in some situations where the assigned object might be modified after being set as a property of some other object (which would mean that modification/mutation would apply to the property as well).

MongoDB: Is it possible to make a case-insensitive query?

These have been tested for string searches

{'_id': /.*CM.*/}               ||find _id where _id contains   ->CM
{'_id': /^CM/}                  ||find _id where _id starts     ->CM
{'_id': /CM$/}                  ||find _id where _id ends       ->CM

{'_id': /.*UcM075237.*/i}       ||find _id where _id contains   ->UcM075237, ignore upper/lower case
{'_id': /^UcM075237/i}          ||find _id where _id starts     ->UcM075237, ignore upper/lower case
{'_id': /UcM075237$/i}          ||find _id where _id ends       ->UcM075237, ignore upper/lower case

Python: Differentiating between row and column vectors

If I want a 1x3 array, or 3x1 array:

import numpy as np
row_arr = np.array([1,2,3]).reshape((1,3))
col_arr = np.array([1,2,3]).reshape((3,1)))

Check your work:

row_arr.shape  #returns (1,3)
col_arr.shape  #returns (3,1)

I found a lot of answers here are helpful, but much too complicated for me. In practice I come back to shape and reshape and the code is readable: very simple and explicit.

Dynamically select data frame columns using $ and a character value

too late.. but I guess I have the answer -

Here's my sample study.df dataframe -

   >study.df
   study   sample       collection_dt other_column
   1 DS-111 ES768098 2019-01-21:04:00:30         <NA>
   2 DS-111 ES768099 2018-12-20:08:00:30   some_value
   3 DS-111 ES768100                <NA>   some_value

And then -

> ## Selecting Columns in an Given order
> ## Create ColNames vector as per your Preference
> 
> selectCols <- c('study','collection_dt','sample')
> 
> ## Select data from Study.df with help of selection vector
> selectCols %>% select(.data=study.df,.)
   study       collection_dt   sample
1 DS-111 2019-01-21:04:00:30 ES768098
2 DS-111 2018-12-20:08:00:30 ES768099
3 DS-111                <NA> ES768100
> 

How To Accept a File POST

See the code below, adapted from this article, which demonstrates the simplest example code I could find. It includes both file and memory (faster) uploads.

public HttpResponseMessage Post()
{
    var httpRequest = HttpContext.Current.Request;
    if (httpRequest.Files.Count < 1)
    {
        return Request.CreateResponse(HttpStatusCode.BadRequest);
    }

    foreach(string file in httpRequest.Files)
    {
        var postedFile = httpRequest.Files[file];
        var filePath = HttpContext.Current.Server.MapPath("~/" + postedFile.FileName);
        postedFile.SaveAs(filePath);
        // NOTE: To store in memory use postedFile.InputStream
    }

    return Request.CreateResponse(HttpStatusCode.Created);
}

WPF - add static items to a combo box

You can also add items in code:

cboWhatever.Items.Add("SomeItem");

Also, to add something where you control display/value, (almost categorically needed in my experience) you can do so. I found a good stackoverflow reference here:

Key Value Pair Combobox in WPF

Sum-up code would be something like this:

ComboBox cboSomething = new ComboBox();
cboSomething.DisplayMemberPath = "Key";
cboSomething.SelectedValuePath = "Value";
cboSomething.Items.Add(new KeyValuePair<string, string>("Something", "WhyNot"));
cboSomething.Items.Add(new KeyValuePair<string, string>("Deus", "Why"));
cboSomething.Items.Add(new KeyValuePair<string, string>("Flirptidee", "Stuff"));
cboSomething.Items.Add(new KeyValuePair<string, string>("Fernum", "Blictor"));

Random state (Pseudo-random number) in Scikit learn

If you don't mention the random_state in the code, then whenever you execute your code a new random value is generated and the train and test datasets would have different values each time.

However, if you use a particular value for random_state(random_state = 1 or any other value) everytime the result will be same,i.e, same values in train and test datasets. Refer below code:

import pandas as pd 
from sklearn.model_selection import train_test_split
test_series = pd.Series(range(100))
size30split = train_test_split(test_series,random_state = 1,test_size = .3)
size25split = train_test_split(test_series,random_state = 1,test_size = .25)
common = [element for element in size25split[0] if element in size30split[0]]
print(len(common))

Doesn't matter how many times you run the code, the output will be 70.

70

Try to remove the random_state and run the code.

import pandas as pd 
from sklearn.model_selection import train_test_split
test_series = pd.Series(range(100))
size30split = train_test_split(test_series,test_size = .3)
size25split = train_test_split(test_series,test_size = .25)
common = [element for element in size25split[0] if element in size30split[0]]
print(len(common))

Now here output will be different each time you execute the code.

regular expression: match any word until first space

^([^\s]+) use this it correctly matches only the first word you can test this using this link https://regex101.com/

Complete list of reasons why a css file might not be working

The URL http://fakedomain.com/smilemachine/html.css in your <link> Tag is wrong. File not Found.

python: sys is not defined

I'm guessing your code failed BEFORE import sys, so it can't find it when you handle the exception.

Also, you should indent the your code whithin the try block.

try:

import sys
# .. other safe imports
try:
    import numpy as np
    # other unsafe imports
except ImportError:
    print "Error: missing one of the libraries (numpy, pyfits, scipy, matplotlib)"
    sys.exit()

JavaScript DOM: Find Element Index In Container

For just elements this can be used to find the index of an element amongst it's sibling elements:

function getElIndex(el) {
    for (var i = 0; el = el.previousElementSibling; i++);
    return i;
}

Note that previousElementSibling isn't supported in IE<9.

What does += mean in Python?

Google 'python += operator' leads you to http://docs.python.org/library/operator.html

Search for += once the page loads up for a more detailed answer.

Detect if device is iOS

Wherever possible when adding Modernizr tests you should add a test for a feature, rather than a device or operating system. There's nothing wrong with adding ten tests all testing for iPhone if that's what it takes. Some things just can't be feature detected.

    Modernizr.addTest('inpagevideo', function ()
    {
        return navigator.userAgent.match(/(iPhone|iPod)/g) ? false : true;
    });

For instance on the iPhone (not the iPad) video cannot be played inline on a webpage, it opens up full screen. So I created a test 'no-inpage-video'

You can then use this in css (Modernizr adds a class .no-inpagevideo to the <html> tag if the test fails)

.no-inpagevideo video.product-video 
{
     display: none;
}

This will hide the video on iPhone (what I'm actually doing in this case is showing an alternative image with an onclick to play the video - I just don't want the default video player and play button to show).

How do the major C# DI/IoC frameworks compare?

See for a comparison of net-ioc-frameworks on google code including linfu and spring.net that are not on your list while i write this text.

I worked with spring.net: It has many features (aop, libraries , docu, ...) and there is a lot of experience with it in the dotnet and the java-world. The features are modularized so you donot have to take all features. The features are abstractions of common issues like databaseabstraction, loggingabstraction. however it is difficuilt to do and debug the IoC-configuration.

From what i have read so far: If i had to chooseh for a small or medium project i would use ninject since ioc-configuration is done and debuggable in c#. But i havent worked with it yet. for large modular system i would stay with spring.net because of abstraction-libraries.

Using ALTER to drop a column if it exists in MySQL

You can use this script, use your column, schema and table name

 IF EXISTS (SELECT *
                         FROM INFORMATION_SCHEMA.COLUMNS
                         WHERE TABLE_NAME = 'TableName' AND COLUMN_NAME = 'ColumnName' 
                                             AND TABLE_SCHEMA = SchemaName)
    BEGIN
       ALTER TABLE TableName DROP COLUMN ColumnName;
    END;

Match linebreaks - \n or \r\n?

Gonna answer in opposite direction.

2) For a full explanation about \r and \n I have to refer to this question, which is far more complete than I will post here: Difference between \n and \r?

Long story short, Linux uses \n for a new-line, Windows \r\n and old Macs \r. So there are multiple ways to write a newline. Your second tool (RegExr) does for example match on the single \r.

1) [\r\n]+ as Ilya suggested will work, but will also match multiple consecutive new-lines. (\r\n|\r|\n) is more correct.

Constructor overloading in Java - best practice

Constructor overloading is like method overloading. Constructors can be overloaded to create objects in different ways.

The compiler differentiates constructors based on how many arguments are present in the constructor and other parameters like the order in which the arguments are passed.

For further details about java constructor, please visit https://tecloger.com/constructor-in-java/

What is the best way to merge mp3 files?

MP3 files have headers you need to respect.

You could ether use a library like Open Source Audio Library Project and write a tool around it. Or you can use a tool that understands mp3 files like Audacity.

Flutter command not found

So far, looking all the solution, none of them worked for me.

So I did it, with the help of alias in Linux

You set the alias as,

alias flutter='~/your/path/to/flutter/bin/./flutter'

Now, just type flutter doctor to see if it works.

To create alias permanently, See

SQL User Defined Function Within Select

If it's a table-value function (returns a table set) you simply join it as a Table

this function generates one column table with all the values from passed comma-separated list

SELECT * FROM dbo.udf_generate_inlist_to_table('1,2,3,4')

Bootstrap 3 Align Text To Bottom of Div

I collected some ideas from other SO question (largely from here and this css page)

Fiddle

The idea is to use relative and absolute positioning to move your line to the bottom:

@media (min-width: 768px ) {
.row {
    position: relative;
}

#bottom-align-text {
    position: absolute;
    bottom: 0;
    right: 0;
  }}

The display:flex option is at the moment a solution to make the div get the same size as its parent. This breaks on the other hand the bootstrap possibilities to auto-linebreak on small devices by adding col-sx-12 class. (This is why the media query is needed)

Setting a system environment variable from a Windows batch file?

Simple example for how to set JAVA_HOME with setx.exe in command line:

setx JAVA_HOME "C:\Program Files (x86)\Java\jdk1.7.0_04"

This will set environment variable "JAVA_HOME" for current user. If you want to set a variable for all users, you have to use option "-m". Here is an example:

setx -m JAVA_HOME "C:\Program Files (x86)\Java\jdk1.7.0_04"

Note: you have to execute this command as Administrator.

Note: Make sure to run the command setx from an command-line Admin window

What charset does Microsoft Excel use when saving files?

Russian Edition offers CSV, CSV (Macintosh) and CSV (DOS).

When saving in plain CSV, it uses windows-1251.

I just tried to save French word Résumé along with the Russian text, it saved it in HEX like 52 3F 73 75 6D 3F, 3F being the ASCII code for question mark.

When I opened the CSV file, the word, of course, became unreadable (R?sum?)

Why doesn't Console.Writeline, Console.Write work in Visual Studio Express?

The output window isn't the console. Try the methods in System.Diagnostics.Debug

Laravel 5.4 create model, controller and migration in single artisan command

You can use -m -c -r to make migration, model and controller.

php artisan make:model Post -m -c -r

SyntaxError: missing ) after argument list

For me, once there was a mistake in spelling of function

For e.g. instead of

$(document).ready(function(){

});

I wrote

$(document).ready(funciton(){

});

So keep that also in check

How to join three table by laravel eloquent model

$articles =DB::table('articles')
                ->join('categories','articles.id', '=', 'categories.id')
                ->join('user', 'articles.user_id', '=', 'user.id')
                ->select('articles.id','articles.title','articles.body','user.user_name', 'categories.category_name')
                ->get();
return view('myarticlesview',['articles'=>$articles]);

ASP.NET MVC 3 Razor: Include JavaScript file in the head tag

You can use Named Sections.

_Layout.cshtml

<head>
    <script type="text/javascript" src="@Url.Content("/Scripts/jquery-1.6.2.min.js")"></script>
    @RenderSection("JavaScript", required: false)
</head>

_SomeView.cshtml

@section JavaScript
{
   <script type="text/javascript" src="@Url.Content("/Scripts/SomeScript.js")"></script>
   <script type="text/javascript" src="@Url.Content("/Scripts/AnotherScript.js")"></script>
}

Getting list of items inside div using Selenium Webdriver

alternatively, you can try writing a specific element:

    //label[1] is the first element.
    el =  await driver.findElement(By.xpath("//div[@class=\"facetContainerDiv\"]/div/label[1]/input")));
    await el.click();

More information can be found here: https://www.browserstack.com/guide/locators-in-selenium

Why are hexadecimal numbers prefixed with 0x?

Short story: The 0 tells the parser it's dealing with a constant (and not an identifier/reserved word). Something is still needed to specify the number base: the x is an arbitrary choice.

Long story: In the 60's, the prevalent programming number systems were decimal and octal — mainframes had 12, 24 or 36 bits per byte, which is nicely divisible by 3 = log2(8).

The BCPL language used the syntax 8 1234 for octal numbers. When Ken Thompson created B from BCPL, he used the 0 prefix instead. This is great because

  1. an integer constant now always consists of a single token,
  2. the parser can still tell right away it's got a constant,
  3. the parser can immediately tell the base (0 is the same in both bases),
  4. it's mathematically sane (00005 == 05), and
  5. no precious special characters are needed (as in #123).

When C was created from B, the need for hexadecimal numbers arose (the PDP-11 had 16-bit words) and all of the points above were still valid. Since octals were still needed for other machines, 0x was arbitrarily chosen (00 was probably ruled out as awkward).

C# is a descendant of C, so it inherits the syntax.

Jenkins returned status code 128 with github

In my case I had to add the public key to my repo (at Bitbucket) AND use git clone once via ssh to answer yes to the "known host" question the first time.

How to remove the character at a given index from a string in C?

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 50
void dele_char(char s[],char ch)
{
    int i,j;

    for(i=0;s[i]!='\0';i++)
    {
        if(s[i]==ch)
        {
            for(j=i;s[j]!='\0';j++)
            s[j]=s[j+1];
            i--;
        }
    }
}

int main()
{
    char s[MAX],ch;
    printf("Enter the string\n");
    gets(s);
    printf("Enter The char to be deleted\n");
    scanf("%c",&ch);
    dele_char(s,ch);
    printf("After Deletion:= %s\n",s);
    return 0;
}

What is the simplest way to convert array to vector?

Use the vector constructor that takes two iterators, note that pointers are valid iterators, and use the implicit conversion from arrays to pointers:

int x[3] = {1, 2, 3};
std::vector<int> v(x, x + sizeof x / sizeof x[0]);
test(v);

or

test(std::vector<int>(x, x + sizeof x / sizeof x[0]));

where sizeof x / sizeof x[0] is obviously 3 in this context; it's the generic way of getting the number of elements in an array. Note that x + sizeof x / sizeof x[0] points one element beyond the last element.

What is compiler, linker, loader?

Compiler: It is a program which translates a high level language program into a machine language program. A compiler is more intelligent than an assembler. It checks all kinds of limits, ranges, errors etc. But its program run time is more and occupies a larger part of the memory. It has slow speed. Because a compiler goes through the entire program and then translates the entire program into machine codes. If a compiler runs on a computer and produces the machine codes for the same computer then it is known as a self compiler or resident compiler. On the other hand, if a compiler runs on a computer and produces the machine codes for other computer then it is known as a cross compiler.

Linker: In high level languages, some built in header files or libraries are stored. These libraries are predefined and these contain basic functions which are essential for executing the program. These functions are linked to the libraries by a program called Linker. If linker does not find a library of a function then it informs to compiler and then compiler generates an error. The compiler automatically invokes the linker as the last step in compiling a program. Not built in libraries, it also links the user defined functions to the user defined libraries. Usually a longer program is divided into smaller subprograms called modules. And these modules must be combined to execute the program. The process of combining the modules is done by the linker.

Loader: Loader is a program that loads machine codes of a program into the system memory. In Computing, a loader is the part of an Operating System that is responsible for loading programs. It is one of the essential stages in the process of starting a program. Because it places programs into memory and prepares them for execution. Loading a program involves reading the contents of executable file into memory. Once loading is complete, the operating system starts the program by passing control to the loaded program code. All operating systems that support program loading have loaders. In many operating systems the loader is permanently resident in memory.

Apache2: 'AH01630: client denied by server configuration'

In case this helps anyone Googling around like I was, I had this error message trying to access a SVG file on my server, e.g. https://example.com/images/file.svg. Other file types seemed fine, just SVG were failing.

I hunted around /etc/httpd conf files and checked every require all denied type of configuration, and just could not find what config was having this effect.

I turned LogLevel to debug in the VirtualHost config and could see the mod_authz_core logging specifying there was a 'Require all denied' in effect:

[Mon Jun 10 13:09:54.321022 2019] [authz_core:debug] [pid 23459:tid 140576341206784] mod_authz_core.c(817): [client 127.0.0.1:54626] AH01626: authorization result of Require all denied: denied
[Mon Jun 10 13:09:54.321038 2019] [authz_core:debug] [pid 23459:tid 140576341206784] mod_authz_core.c(817): [client 127.0.0.1:54626] AH01626: authorization result of <RequireAny>: denied
[Mon Jun 10 13:09:54.321082 2019] [authz_core:error] [pid 23459:tid 140576341206784] [client 127.0.0.1:54626] AH01630: client denied by server configuration: /home/blah/htdocs/images/file.svg

Through blind testing I moved the file to the root of the web root, and found I could then access it at https://example.com/file.svg .. so it only failed in the 'images' folder. This led me to an .htaccess file in the images folder that I had no idea was there.

Turns out Zen Cart 1.5 comes with an images/.htaccess file that has:

# deny *everything*
 <FilesMatch ".*">
   <IfModule mod_authz_core.c>
     Require all denied
   </IfModule>
   <IfModule !mod_authz_core.c>
     Order Allow,Deny
     Deny from all
   </IfModule>
 </FilesMatch>

 # but now allow just *certain* necessary files:
 <FilesMatch "(?i).*\.(jpe?g|gif|webp|png|swf)$" >
   <IfModule mod_authz_core.c>
     Require all granted
   </IfModule>
   <IfModule !mod_authz_core.c>
     Order Allow,Deny
     Allow from all
   </IfModule>
 </FilesMatch>

This was very annoying and I hope this might remind others to check .htaccess files at every level of the file system leading to the file you're having trouble accessing in case there is this kind of tom foolery going on.

How to rename a class and its corresponding file in Eclipse?

Just rename the class in the source code. Eclipse will point out an error by underlining the class name with a red squiggly line. Hover on that line with your mouse pointer and eclipse will give you the option to rename compilation unit. Click on that.

Copy array items into another array

Extremely fast

I analyse current solutions and propose 2 new (F and G presented in details section) one which are extremely fast for small and medium arrays

Performance

Today 2020.11.13 I perform tests on MacOs HighSierra 10.13.6 on Chrome v86, Safari v13.1.2 and Firefox v82 for chosen solutions

Results

For all browsers

  • solutions based on while-pop-unshift (F,G) are (extremely) fastest on all browsers for small and medium size arrays. For arrays with 50000 elements this solutions slows down on Chrome
  • solutions C,D for arrays 500000 breaks: "RangeError: Maximum call stack size exceeded
  • solution (E) is slowest

enter image description here

Details

I perform 2 tests cases:

  • when arrays have 10 elements - you can run it HERE
  • when arrays have 10k elements - you can run it HERE

Below snippet presents differences between solutions A, B, C, D, E, F(my), G(my), H, I

_x000D_
_x000D_
// https://stackoverflow.com/a/4156145/860099
function A(a,b) {
  return a.concat(b);
}

// https://stackoverflow.com/a/38107399/860099 
function B(a,b) {
  return [...a, ...b];
}

// https://stackoverflow.com/a/32511679/860099
function C(a,b) {
  return (a.push(...b), a);
}

// https://stackoverflow.com/a/4156156/860099
function D(a,b) {
    Array.prototype.push.apply(a, b);
    return a;
}

// https://stackoverflow.com/a/60276098/860099
function E(a,b) {
    return b.reduce((pre, cur) => [...pre, cur], a);
}

// my
function F(a,b) {
    while(b.length) a.push(b.shift());
    return a;
}

// my
function G(a,b) {
    while(a.length) b.unshift(a.pop());
    return b;
}

// https://stackoverflow.com/a/44087401/860099
function H(a, b) {
    var len = b.length;
    var start = a.length;
    a.length = start + len;
    for (var i = 0; i < len; i++ , start++) {
        a[start] = b[i];
    }
    return a;
}

// https://stackoverflow.com/a/51860949/860099
function I(a, b){
   var oneLen = a.length, twoLen = b.length;
   var newArr = [], newLen = newArr.length = oneLen + twoLen;
   for (var i=0, tmp=a[0]; i !== oneLen; ++i) {
        tmp = a[i];
        if (tmp !== undefined || a.hasOwnProperty(i)) newArr[i] = tmp;
    }
    for (var two=0; i !== newLen; ++i, ++two) {
        tmp = b[two];
        if (tmp !== undefined || b.hasOwnProperty(two)) newArr[i] = tmp;
    }
    return newArr;
}






// ---------
// TEST
// ---------

let a1=[1,2,3];
let a2=[4,5,6];

[A,B,C,D,E,F,G,H,I].forEach(f=> {
    console.log(`${f.name}: ${f([...a1],[...a2])}`)
})
_x000D_
_x000D_
_x000D_

And here are example results for chrome

enter image description here

How to upgrade docker container after its image changed

This is something I've also been struggling with for my own images. I have a server environment from which I create a Docker image. When I update the server, I'd like all users who are running containers based on my Docker image to be able to upgrade to the latest server.

Ideally, I'd prefer to generate a new version of the Docker image and have all containers based on a previous version of that image automagically update to the new image "in place." But this mechanism doesn't seem to exist.

So the next best design I've been able to come up with so far is to provide a way to have the container update itself--similar to how a desktop application checks for updates and then upgrades itself. In my case, this will probably mean crafting a script that involves Git pulls from a well-known tag.

The image/container doesn't actually change, but the "internals" of that container change. You could imagine doing the same with apt-get, yum, or whatever is appropriate for you environment. Along with this, I'd update the myserver:latest image in the registry so any new containers would be based on the latest image.

I'd be interested in hearing whether there is any prior art that addresses this scenario.

How to copy data from one table to another new table in MySQL?

CREATE TABLE newTable LIKE oldTable;

Then, to copy the data over

INSERT INTO newTable SELECT * FROM oldTable;

What is the best way to redirect a page using React Router?

You can also use react router dom library useHistory;

`
import { useHistory } from "react-router-dom";

function HomeButton() {
  let history = useHistory();

  function handleClick() {
    history.push("/home");
  }

  return (
    <button type="button" onClick={handleClick}>
      Go home
    </button>
  );
}
`

https://reactrouter.com/web/api/Hooks/usehistory

Check if value already exists within list of dictionaries?

Maybe this helps:

a = [{ 'main_color': 'red', 'second_color':'blue'},
     { 'main_color': 'yellow', 'second_color':'green'},
     { 'main_color': 'yellow', 'second_color':'blue'}]

def in_dictlist((key, value), my_dictlist):
    for this in my_dictlist:
        if this[key] == value:
            return this
    return {}

print in_dictlist(('main_color','red'), a)
print in_dictlist(('main_color','pink'), a)

How to use Apple's new San Francisco font on a webpage

Last tested in 2015

Should use this solution as a last choice, when other solutions don't work.


Original answer:

Work on macOS Chrome/Safari

body { font-family: '.SFNSDisplay-Regular', sans-serif; }

DLL load failed error when importing cv2

this happens because the compiler or the interpreter is finding more than one package of the file, delete all the number of same package you have and then keep only one and then try to install. It serves

How to import image (.svg, .png ) in a React Component

Solved the problem, when moved the folder with the image in src folder. Then I turned to the image (project created through "create-react-app")
let image = document.createElement("img"); image.src = require('../assets/police.png');

How to write to a JSON file in the correct format

To make this work on Ubuntu Linux:

  1. I installed the Ubuntu package ruby-json:

    apt-get install ruby-json
    
  2. I wrote the script in ${HOME}/rubybin/jsonDEMO

  3. $HOME/.bashrc included:

    ${HOME}/rubybin:${PATH}
    

(On this occasion I also typed the above on the bash command line.)

Then it worked when I entered on the command line:

jsonDemo

Razor/CSHTML - Any Benefit over what we have?

Ex Microsoft Developer's Opinion

I worked on a core team for the MSDN website. Now, I use c# razor for ecommerce sites with my programming team and we focus heavy on jQuery front end with back end c# razor pages and LINQ-Entity memory database so the pages are 1-2 millisecond response times even on nested for loops with queries and no page caching. We don't use MVC, just plain ASP.NET with razor pages being mapped with URL Rewrite module for IIS 7, no ASPX pages or ViewState or server-side event programming at all. It doesn't have the extra (unnecessary) layers MVC puts in code constructs for the regex challenged. Less is more for us. Its all lean and mean but I give props to MVC for its testability but that's all.

Razor pages have no event life cycle like ASPX pages. Its just rendering as one requested page. C# is such a great language and Razor gets out of its way nicely to let it do its job. The anonymous typing with generics and linq make life so easy with c# and razor pages. Using Razor pages will help you think and code lighter.

One of the drawback of Razor and MVC is there is no ViewState-like persistence. I needed to implement a solution for that so I ended up writing a jQuery plugin for that here -> http://www.jasonsebring.com/dumbFormState which is an HTML 5 offline storage supported plugin for form state that is working in all major browsers now. It is just for form state currently but you can use window.sessionStorage or window.localStorage very simply to store any kind of state across postbacks or even page requests, I just bothered to make it autosave and namespace it based on URL and form index so you don't have to think about it.

Opacity CSS not working in IE8

None of the answers above worked for me, so I just gave my DIV tag a transparent background image instead, that worked perfectly for all browsers.

How to upload a file in Django?

I faced the similar problem, and solved by django admin site.

# models
class Document(models.Model):
    docfile = models.FileField(upload_to='documents/Temp/%Y/%m/%d')

    def doc_name(self):
        return self.docfile.name.split('/')[-1] # only the name, not full path

# admin
from myapp.models import Document
class DocumentAdmin(admin.ModelAdmin):
    list_display = ('doc_name',)
admin.site.register(Document, DocumentAdmin)

How to write a foreach in SQL Server?

Although cursors usually considered horrible evil I believe this is a case for FAST_FORWARD cursor - the closest thing you can get to FOREACH in TSQL.

Return string Input with parse.string

You don't need to parse the string, it's defined as a string already.

Just do:

    private static String getStringInput (String prompt) {
     String input = EZJ.getUserInput(prompt);
     return input;
    }

Errors: Data path ".builders['app-shell']" should have required property 'class'

This happened to me when I installed Angular 8, there are some incompatibilities I couldn't solve. I had to downgrade because I went down the rabbit hole juggling around with every version until I found one that worked.

First, TypeScript was outdated, the default installation added a reference to TypeScript 3.1.6 and it requires 3.4 or greater.

npm install typescript@">=3.4 <3.5"

Second, using the devkit 0.800.1 or 0.800.1 always ended up in incompatibilities. I tried many combinations but I am not sure it's fully compatible yet, specially because I am using one bootstrap a bit older and I cannot upgrade yet.

Finally I tried to downgrade (go to package.json and find the devDependencies) until one of them worked.

@angular-devkit/build-angular": "0.13.4"

I am sure your problem is dependencies versions but I cannot tell you which one. Give it a try downgrading.

Disabling Chrome Autofill

I finally solved this by putting in a non duplicate variable in the input field - i used php time() like this:

<input type="text" name="town['.time().']" >

This was interfering mostly n android. All i did on the server side was to do a foreach loop on the input name - the issue is if chrome recognizes the name attribute it WILL auto populate.

Nothing else even worked for me.

How to output messages to the Eclipse console when developing for Android

i use below log format for print my content in logCat

Log.e("Msg","What you have to print");

PostgreSQL delete all content

The content of the table/tables in PostgreSQL database can be deleted in several ways.

Deleting table content using sql:

Deleting content of one table:

TRUNCATE table_name;
DELETE FROM table_name;

Deleting content of all named tables:

TRUNCATE table_a, table_b, …, table_z;

Deleting content of named tables and tables that reference to them (I will explain it in more details later in this answer):

TRUNCATE table_a, table_b CASCADE;

Deleting table content using pgAdmin:

Deleting content of one table:

Right click on the table -> Truncate

Deleting content of table and tables that reference to it:

Right click on the table -> Truncate Cascaded

Difference between delete and truncate:

From the documentation:

DELETE deletes rows that satisfy the WHERE clause from the specified table. If the WHERE clause is absent, the effect is to delete all rows in the table. http://www.postgresql.org/docs/9.3/static/sql-delete.html

TRUNCATE is a PostgreSQL extension that provides a faster mechanism to remove all rows from a table. TRUNCATE quickly removes all rows from a set of tables. It has the same effect as an unqualified DELETE on each table, but since it does not actually scan the tables it is faster. Furthermore, it reclaims disk space immediately, rather than requiring a subsequent VACUUM operation. This is most useful on large tables. http://www.postgresql.org/docs/9.1/static/sql-truncate.html

Working with table that is referenced from other table:

When you have database that has more than one table the tables have probably relationship. As an example there are three tables:

create table customers (
customer_id int not null,
name varchar(20),
surname varchar(30),
constraint pk_customer primary key (customer_id)
);

create table orders (
order_id int not null,
number int not null,
customer_id int not null,
constraint pk_order primary key (order_id),
constraint fk_customer foreign key (customer_id) references customers(customer_id)
);

create table loyalty_cards (
card_id int not null,
card_number varchar(10) not null,
customer_id int not null,
constraint pk_card primary key (card_id),
constraint fk_customer foreign key (customer_id) references customers(customer_id)
);

And some prepared data for these tables:

insert into customers values (1, 'John', 'Smith');

insert into orders values 
(10, 1000, 1),
(11, 1009, 1),
(12, 1010, 1);        

insert into loyalty_cards values (100, 'A123456789', 1);

Table orders references table customers and table loyalty_cards references table customers. When you try to TRUNCATE / DELETE FROM the table that is referenced by other table/s (the other table/s has foreign key constraint to the named table) you get an error. To delete content from all three tables you have to name all these tables (the order is not important)

TRUNCATE customers, loyalty_cards, orders;

or just the table that is referenced with CASCADE key word (you can name more tables than just one)

TRUNCATE customers CASCADE;

The same applies for pgAdmin. Right click on customers table and choose Truncate Cascaded.

Intellij Cannot resolve symbol on import

File -> Invalidate Caches/Restart or rebuilding the project did not work wor me.

What worked for my Gradle project was to "Refresh all Gradle projects" from the Gradle tab on top-right corner of IntelliJ v2017, using the yellow marked button shown below:

enter image description here

Pass a PHP string to a JavaScript variable (and escape newlines)

I'm not sure if this is bad practice or no, but my team and I have been using a mixed html, JS, and php solution. We start with the PHP string we want to pull into a JS variable, lets call it:

$someString

Next we use in-page hidden form elements, and have their value set as the string:

<form id="pagePhpVars" method="post">
<input type="hidden" name="phpString1" id="phpString1" value="'.$someString.'" />
</form>

Then its a simple matter of defining a JS var through document.getElementById:

<script type="text/javascript" charset="UTF-8">
    var moonUnitAlpha = document.getElementById('phpString1').value;
</script>

Now you can use the JS variable "moonUnitAlpha" anywhere you want to grab that PHP string value. This seems to work really well for us. We'll see if it holds up to heavy use.

HTML Upload MAX_FILE_SIZE does not appear to work

To anyone who had been wonderstruck about some files being easily uploaded and some not, it could be a size issue. I'm sharing this as I was stuck with my PHP code not uploading large files and I kept assuming it wasn't uploading any Excel files. So, if you are using PHP and you want to increase the file upload limit, go to the php.ini file and make the following modifications:

  • upload_max_filesize = 2M

to be changed to

  • upload_max_filesize = 10M

  • post_max_size = 10M

or the size required. Then restart the Apache server and the upload will start magically working. Hope this will be of help to someone.

Failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED

In my case the answer is pretty simple. Please check carefully the hardcoded url port: it is 8080. For some reason the value has changed to: for example 3030.

Just refresh the port in your ajax url string to the appropriate one.

conn = new WebSocket('ws://localhost:3030'); //should solve the issue

Convert LocalDateTime to LocalDateTime in UTC

Here's a simple little utility class that you can use to convert local date times from zone to zone, including a utility method directly to convert a local date time from the current zone to UTC (with main method so you can run it and see the results of a simple test):

import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;

public final class DateTimeUtil {
    private DateTimeUtil() {
        super();
    }

    public static void main(final String... args) {
        final LocalDateTime now = LocalDateTime.now();
        final LocalDateTime utc = DateTimeUtil.toUtc(now);

        System.out.println("Now: " + now);
        System.out.println("UTC: " + utc);
    }

    public static LocalDateTime toZone(final LocalDateTime time, final ZoneId fromZone, final ZoneId toZone) {
        final ZonedDateTime zonedtime = time.atZone(fromZone);
        final ZonedDateTime converted = zonedtime.withZoneSameInstant(toZone);
        return converted.toLocalDateTime();
    }

    public static LocalDateTime toZone(final LocalDateTime time, final ZoneId toZone) {
        return DateTimeUtil.toZone(time, ZoneId.systemDefault(), toZone);
    }

    public static LocalDateTime toUtc(final LocalDateTime time, final ZoneId fromZone) {
        return DateTimeUtil.toZone(time, fromZone, ZoneOffset.UTC);
    }

    public static LocalDateTime toUtc(final LocalDateTime time) {
        return DateTimeUtil.toUtc(time, ZoneId.systemDefault());
    }
}

How to find all occurrences of an element in a list

import numpy as np
import random  # to create test list

# create sample list
random.seed(365)
l = [random.choice(['s1', 's2', 's3', 's4']) for _ in range(20)]

# convert the list to an array for use with these numpy methods
a = np.array(l)

# create a dict of each unique entry and the associated indices
idx = {v: np.where(a == v)[0].tolist() for v in np.unique(a)}

# print(idx)
{'s1': [7, 9, 10, 11, 17],
 's2': [1, 3, 6, 8, 14, 18, 19],
 's3': [0, 2, 13, 16],
 's4': [4, 5, 12, 15]}

# find a single element with 
idx = np.where(a == 's1')

print(idx)
[out]:
(array([ 7,  9, 10, 11, 17], dtype=int64),)

%timeit

  • Find indices of a single element in a 2M element list with 4 unique elements
# create 2M element list
random.seed(365)
l = [random.choice(['s1', 's2', 's3', 's4']) for _ in range(2000000)]

# create array
a = np.array(l)

# np.where
%timeit np.where(a == 's1')
[out]:
25.9 ms ± 827 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)

# list-comprehension
%timeit [i for i, x in enumerate(l) if x == "s1"]
[out]:
175 ms ± 2.73 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

PHPExcel how to set cell value dynamically

I asume you have connected to your database already.

$sql = "SELECT * FROM my_table";
$result = mysql_query($sql);

$row = 1; // 1-based index
while($row_data = mysql_fetch_assoc($result)) {
    $col = 0;
    foreach($row_data as $key=>$value) {
        $objPHPExcel->getActiveSheet()->setCellValueByColumnAndRow($col, $row, $value);
        $col++;
    }
    $row++;
}

How do I remove files saying "old mode 100755 new mode 100644" from unstaged changes in Git?

You can use the following command to change your file mode back. git add --chmod=+x -- filename Then commit to the branch.

How to fix "Headers already sent" error in PHP

This error message gets triggered when anything is sent before you send HTTP headers (with setcookie or header). Common reasons for outputting something before the HTTP headers are:

  • Accidental whitespace, often at the beginning or end of files, like this:

     <?php
    // Note the space before "<?php"
    ?>
    

       To avoid this, simply leave out the closing ?> - it's not required anyways.

  • Byte order marks at the beginning of a php file. Examine your php files with a hex editor to find out whether that's the case. They should start with the bytes 3F 3C. You can safely remove the BOM EF BB BF from the start of files.
  • Explicit output, such as calls to echo, printf, readfile, passthru, code before <? etc.
  • A warning outputted by php, if the display_errors php.ini property is set. Instead of crashing on a programmer mistake, php silently fixes the error and emits a warning. While you can modify the display_errors or error_reporting configurations, you should rather fix the problem.
    Common reasons are accesses to undefined elements of an array (such as $_POST['input'] without using empty or isset to test whether the input is set), or using an undefined constant instead of a string literal (as in $_POST[input], note the missing quotes).

Turning on output buffering should make the problem go away; all output after the call to ob_start is buffered in memory until you release the buffer, e.g. with ob_end_flush.

However, while output buffering avoids the issues, you should really determine why your application outputs an HTTP body before the HTTP header. That'd be like taking a phone call and discussing your day and the weather before telling the caller that he's got the wrong number.

Good examples using java.util.logging

Should declare logger like this:

private final static Logger LOGGER = Logger.getLogger(MyClass.class.getName());

so if you refactor your class name it follows.

I wrote an article about java logger with examples here.

How to Specify Eclipse Proxy Authentication Credentials?

Add the following line at the end of your eclipse.ini file

-Dorg.eclipse.ecf.provider.filetransfer.excludeContributors=org.eclipse.ecf.provider.filetransfer.httpclient4

No resource found that matches the given name: attr 'android:keyboardNavigationCluster'. when updating to Support Library 26.0.0

For this you have to do below things 1.right click the project click.

2.open module settings->in properties tab->change the compile sdk and build tool version into 26,26.0.0.

3.click ok.

Its working for me after an hour tried.

Issue with parsing the content from json file with Jackson & message- JsonMappingException -Cannot deserialize as out of START_ARRAY token

JsonMappingException: out of START_ARRAY token exception is thrown by Jackson object mapper as it's expecting an Object {} whereas it found an Array [{}] in response.

This can be solved by replacing Object with Object[] in the argument for geForObject("url",Object[].class). References:

  1. Ref.1
  2. Ref.2
  3. Ref.3

how to do "press enter to exit" in batch

Default interpreters from Microsoft are done in a way, that causes them exit when they reach EOF. If rake is another batch file, command interpreter switches to it and exits when rake interpretation is finished. To prevent this write:

@echo off
cls
call rake
pause

IMHO, call operator will lauch another instance of intepretator thereby preventing the current one interpreter from switching to another input file.

CodeIgniter: 404 Page Not Found on Live Server

Changing the first letter to uppercase on the file's name and class name works.

file: controllers/Login.php

class: class Login extends CI_Controller { ... }

The file name, as the class name, should starts with capital letter. This rule applys to models too.

https://www.codeigniter.com/user_guide/general/models.html

How to add parameters into a WebRequest?

Hope this works

webRequest.Credentials= new NetworkCredential("API_User","API_Password");

How do I access ViewBag from JS

<script type="text/javascript">
      $(document).ready(function() {
                showWarning('@ViewBag.Message');
      });

</script>

You can use ViewBag.PropertyName in javascript like this.

Root password inside a Docker container

You can log into the Docker container using the root user (ID = 0) instead of the provided default user when you use the -u option. E.g.

docker exec -u 0 -it mycontainer bash

root (id = 0) is the default user within a container. The image developer can create additional users. Those users are accessible by name. When passing a numeric ID, the user does not have to exist in the container.

from Docker documentation

Update: Of course you can also use the Docker management command for containers to run this:

docker container exec -u 0 -it mycontainer bash

Reading entire html file to String?

I prefers using Guava :

import com.google.common.base.Charsets;
import com.google.common.io.Files;
File file = new File("/path/to/file", Charsets.UTF_8);
String content = Files.toString(file);

Bootstrap NavBar with left, center or right aligned items

This is a dated question but I found an alternate solution to share right from the bootstrap github page. The documentation has not been updated and there are other questions on SO asking for the same solution albeit on slightly different questions. This solution is not specific to your case but as you can see the solution is the <div class="container"> right after <nav class="navbar navbar-default navbar-fixed-top"> but can also be replaced with <div class="container-fluid" as needed.

<!DOCTYPE html>
<html>

<head>
  <title>Navbar right padding broken </title>
  <script src="//code.jquery.com/jquery-2.1.4.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
  <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" />
</head>

<body>
  <nav class="navbar navbar-default navbar-fixed-top">
    <div class="container">
      <div class="navbar-header">
        <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-ex1-collapse">
          <span class="sr-only">Toggle navigation</span>
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>
        </button>
        <a href="#/" class="navbar-brand">Hello</a>
      </div>
      <div class="collapse navbar-collapse navbar-ex1-collapse">

        <ul class="nav navbar-nav navbar-right">
          <li>
            <div class="btn-group navbar-btn" role="group" aria-label="...">
              <button type="button" class="btn btn-default" data-toggle="modal" data-target="#modalLogin">Se connecter</button>
              <button type="button" class="btn btn-default" data-toggle="modal" data-target="#modalSignin">Créer un compte</button>
            </div>
          </li>
        </ul>
      </div>
    </div>
  </nav>
</body>

</html>

The solution was found on a fiddle on this page: https://github.com/twbs/bootstrap/issues/18362

and is listed as a won't fix in V3.

connecting to mysql server on another PC in LAN

actually you shouldn't specify port in the host name. Mysql has special option for port (if port differs from default)

kind of

mysql --host=192.168.1.2 --port=3306

FileNotFoundException while getting the InputStream object from HttpURLConnection

Please change

con = (HttpURLConnection) new URL("http://localhost:8080/myapp/service/generate").openConnection();

To

con = (HttpURLConnection) new URL("http://YOUR_IP:8080/myapp/service/generate").openConnection();

Why am I getting the message, "fatal: This operation must be run in a work tree?"

Create a bare GIT repository

A small rant: git is unable to create a normal bare repository by itself. Stupid git indeed.

To be precise, it is not possible to clone empty repositories. So an empty repository is a useless repository. Indeed, you normally create an empty repository and immediately fill it:

git init
git add .

However, git add is not possible when you create a bare repository:

git --bare init
git add .

gives an error "fatal: This operation must be run in a work tree".

You can't check it out either:

Initialized empty Git repository in /home/user/myrepos/.git/
fatal: http://repository.example.org/projects/myrepos.git/info/refs not found: did you run git update-server-info on the server?

git --bare init
git update-server-info # this creates the info/refs file
chown -R <user>:<group> . # make sure others can update the repository

The solution is to create another repository elsewhere, add a file in that repository and, push it to the bare repository.

mkdir temp; cd temp
git init
touch .gitignore
git add .gitignore
git commit -m "Initial commit"
git push (url or path of bare repository) master
cd ..; rm -rf temp

hope this can help u

How can I get the actual video URL of a YouTube live stream?

Yes this is possible Since the question is update, this solution can only gives you the embed url not the HLS url, check @JAL answer. with the ressource search.list and the parameters:

* part: id
* channelId: UCURGpU4lj3dat246rysrWsw
* eventType: live
* type: video

Request :

GET https://www.googleapis.com/youtube/v3/search?part=snippet&channelId=UCURGpU4lj3dat246rysrWsw&eventType=live&type=video&key={YOUR_API_KEY}

Result:

 "items": [
  {
   "kind": "youtube#searchResult",
   "etag": "\"DsOZ7qVJA4mxdTxZeNzis6uE6ck/enc3-yCp8APGcoiU_KH-mSKr4Yo\"",
   "id": {
    "kind": "youtube#video",
    "videoId": "WVZpCdHq3Qg"
   }
  },

Then get the videoID value WVZpCdHq3Qg for example and add the value to this url:

https://www.youtube.com/embed/ + videoID
https://www.youtube.com/watch?v= + videoID

Responding with a JSON object in Node.js (converting object/array to JSON string)

Using res.json with Express:

function random(response) {
  console.log("response.json sets the appropriate header and performs JSON.stringify");
  response.json({ 
    anObject: { item1: "item1val", item2: "item2val" }, 
    anArray: ["item1", "item2"], 
    another: "item"
  });
}

Alternatively:

function random(response) {
  console.log("Request handler random was called.");
  response.writeHead(200, {"Content-Type": "application/json"});
  var otherArray = ["item1", "item2"];
  var otherObject = { item1: "item1val", item2: "item2val" };
  var json = JSON.stringify({ 
    anObject: otherObject, 
    anArray: otherArray, 
    another: "item"
  });
  response.end(json);
}

Get Path from another app (WhatsApp)

Using the code example below will return to you the bitmap :

BitmapFactory.decodeStream(getContentResolver().openInputStream(Uri.parse("content://com.whatsapp.provider.media/item/128752")))

After that you all know what you have to do.

Why do I get an error instantiating an interface?

IUser is the interface, you can't instantiate the interface.

You need to instantiate the concrete class that implements the interface.

IUser user = new User();

or

User user = new User();

Git: See my last commit

As determined via comments, it appears that the OP is looking for

$ git log --name-status HEAD^..HEAD

This is also very close to the output you'd get from svn status or svn log -v, which many people coming from subversion to git are familiar with.

--name-status is the key here; as noted by other folks in this question, you can use git log -1, git show, and git diff to get the same sort of output. Personally, I tend to use git show <rev> when looking at individual revisions.

Convert data.frame column to a vector?

If you just use the extract operator it will work. By default, [] sets option drop=TRUE, which is what you want here. See ?'[' for more details.

>  a1 = c(1, 2, 3, 4, 5)
>  a2 = c(6, 7, 8, 9, 10)
>  a3 = c(11, 12, 13, 14, 15)
>  aframe = data.frame(a1, a2, a3)
> aframe[,'a2']
[1]  6  7  8  9 10
> class(aframe[,'a2'])
[1] "numeric"

How to find which git branch I am on when my disk is mounted on other server

You can look at the HEAD pointer (stored in .git/HEAD) to see the sha1 of the currently checked-out commit, or it will be of the format ref: refs/heads/foo for example if you have a local ref foo checked out.

EDIT: If you'd like to do this from a shell, git symbolic-ref HEAD will give you the same information.

how to prevent adding duplicate keys to a javascript array

You can try this:

var names = ["Mike","Matt","Nancy","Adam","Jenny","Nancy","Carl"];
var uniqueNames = [];
$.each(names, function(i, el){
if($.inArray(el, uniqueNames) === -1) uniqueNames.push(el);
});

Easiest way to find duplicate values in a JavaScript array

Check if image exists on server using JavaScript?

You may call this JS function to check if file exists on the Server:

function doesFileExist(urlToFile)
{
    var xhr = new XMLHttpRequest();
    xhr.open('HEAD', urlToFile, false);
    xhr.send();

    if (xhr.status == "404") {
        console.log("File doesn't exist");
        return false;
    } else {
        console.log("File exists");
        return true;
    }
}

Passing dynamic javascript values using Url.action()

The @Url.Action() method is proccess on the server-side, so you cannot pass a client-side value to this function as a parameter. You can concat the client-side variables with the server-side url generated by this method, which is a string on the output. Try something like this:

var firstname = "abc";
var username = "abcd";
location.href = '@Url.Action("Display", "Customer")?uname=' + firstname + '&name=' + username;

The @Url.Action("Display", "Customer") is processed on the server-side and the rest of the string is processed on the client-side, concatenating the result of the server-side method with the client-side.

Passing an array/list into a Python function

Python lists (which are not just arrays because their size can be changed on the fly) are normal Python objects and can be passed in to functions as any variable. The * syntax is used for unpacking lists, which is probably not something you want to do now.

Invoking a static method using reflection

// String.class here is the parameter type, that might not be the case with you
Method method = clazz.getMethod("methodName", String.class);
Object o = method.invoke(null, "whatever");

In case the method is private use getDeclaredMethod() instead of getMethod(). And call setAccessible(true) on the method object.

How to make the webpack dev server run on port 80 and on 0.0.0.0 to make it publicly accessible?

I tried the solutions above, but had no luck. I noticed this line in my project's package.json:

 "bin": {
"webpack-dev-server": "bin/webpack-dev-server.js"

},

I looked at bin/webpack-dev-server.js and found this line:

.describe("port", "The port").default("port", 8080)

I changed the port to 3000. A bit of a brute force approach, but it worked for me.

Global constants file in Swift

Constant.swift

import Foundation

let kBaseURL = NSURL(string: "http://www.example.com/")

ViewController.swift

var manager = AFHTTPRequestOperationManager(baseURL: kBaseURL)

How to save CSS changes of Styles panel of Chrome Developer Tools?

DevTools tech writer and developer advocate here.

Starting in Chrome 65, Local Overrides is a new, lightweight way to do this. This is a different feature than Workspaces.

Set up Overrides

  1. Go to Sources panel.
  2. Go to Overrides tab.
  3. Click Select Folder For Overrides.
  4. Select which directory you want to save your changes to.
  5. At the top of your viewport, click Allow to give DevTools read and write access to the directory.
  6. Make your changes. In the GIF below, you can see that the background:rosybrown change persists across page loads.

overrides demo

How overrides work

When you make a change in DevTools, DevTools saves the change to a modified copy of the file on your computer. When you reload the page, DevTools serves the modified file, rather than the network resource.

The difference between overrides and workspaces

Workspaces is designed to let you use DevTools as your IDE. It maps your repository code to the network code, using source maps. The real benefit is if you're minifying your code, or using code that needs to get transpiled, like SCSS, then the changes you make in DevTools (usually) get mapped back into your original source code. Overrides, on the other hand, let you modify and save any file on the web. It's a good solution if you just want to quickly experiment with changes, and save those changes across page loads.

Comment out HTML and PHP together

PHP parser will search your entire code for <?php (or <? if short_open_tag = On), so HTML comment tags have no effect on PHP parser behavior & if you don't want to parse your PHP code, you have to use PHP commenting directives(/* */ or //).