SyntaxFix

Programs & Examples On #Counter

A Counter is a container(/bag/multiset/etc.) that keeps track of how many times equivalent values are added.

Count characters in textarea

What errors are you seeing in the browser? I can understand why your code doesn't work if what you posted was incomplete, but without knowing that I can't know for sure.

<!DOCTYPE html>
<html>
  <head>
    <script src="http://code.jquery.com/jquery-1.5.js"></script>
    <script>
      function countChar(val) {
        var len = val.value.length;
        if (len >= 500) {
          val.value = val.value.substring(0, 500);
        } else {
          $('#charNum').text(500 - len);
        }
      };
    </script>
  </head>

  <body>
    <textarea id="field" onkeyup="countChar(this)"></textarea>
    <div id="charNum"></div>
  </body>

</html>

... works fine for me.

Edit: You should probably clear the charNum div, or write something, if they are over the limit.

jQuery counter to count up to a target number

Don't know about plugins but this shouldn't be too hard:

;(function($) {        
     $.fn.counter = function(options) {
        // Set default values
        var defaults = {
            start: 0,
            end: 10,
            time: 10,
            step: 1000,
            callback: function() { }
        }
        var options = $.extend(defaults, options);            
        // The actual function that does the counting
        var counterFunc = function(el, increment, end, step) {
            var value = parseInt(el.html(), 10) + increment;
            if(value >= end) {
                el.html(Math.round(end));
                options.callback();
            } else {
                el.html(Math.round(value));
                setTimeout(counterFunc, step, el, increment, end, step);
            }
        }            
        // Set initial value
        $(this).html(Math.round(options.start));
        // Calculate the increment on each step
        var increment = (options.end - options.start) / ((1000 / options.step) * options.time);            
        // Call the counter function in a closure to avoid conflicts
        (function(e, i, o, s) {
            setTimeout(counterFunc, s, e, i, o, s);
        })($(this), increment, options.end, options.step);
    }
})(jQuery);

Usage:

$('#foo').counter({
    start: 1000,
    end: 4500,
    time: 8,
    step: 500,
    callback: function() {
        alert("I'm done!");
    }
});

Example:

http://www.ulmanen.fi/stuff/counter.php

I guess the usage is self-explanatory; in this example, the counter will start from 1000 and count up to 4500 in 8 seconds in 500ms intervals, and will call the callback function when the counting is done.

Code for a simple JavaScript countdown timer?

My solution works with MySQL date time formats and provides a callback function. on complition. Disclaimer: works only with minutes and seconds, as this is what I needed.

jQuery.fn.countDownTimer = function(futureDate, callback){
    if(!futureDate){
        throw 'Invalid date!';
    }

    var currentTs = +new Date();
    var futureDateTs = +new Date(futureDate);

    if(futureDateTs <= currentTs){
        throw 'Invalid date!';
    }


    var diff = Math.round((futureDateTs - currentTs) / 1000);
    var that = this;

    (function countdownLoop(){
        // Get hours/minutes from timestamp
        var m = Math.floor(diff % 3600 / 60);
        var s = Math.floor(diff % 3600 % 60);
        var text = zeroPad(m, 2) + ':' + zeroPad(s, 2);

        $(that).text(text);

        if(diff <= 0){
            typeof callback === 'function' ? callback.call(that) : void(0);
            return;
        }

        diff--;
        setTimeout(countdownLoop, 1000);
    })();

    function zeroPad(num, places) {
      var zero = places - num.toString().length + 1;
      return Array(+(zero > 0 && zero)).join("0") + num;
    }
}

// $('.heading').countDownTimer('2018-04-02 16:00:59', function(){ // on complete})

Counter increment in Bash loop not working

First, you are not increasing the counter. Changing COUNTER=$((COUNTER)) into COUNTER=$((COUNTER + 1)) or COUNTER=$[COUNTER + 1] will increase it.

Second, it's trickier to back-propagate subshell variables to the callee as you surmise. Variables in a subshell are not available outside the subshell. These are variables local to the child process.

One way to solve it is using a temp file for storing the intermediate value:

TEMPFILE=/tmp/$$.tmp
echo 0 > $TEMPFILE

# Loop goes here
  # Fetch the value and increase it
  COUNTER=$[$(cat $TEMPFILE) + 1]

  # Store the new value
  echo $COUNTER > $TEMPFILE

# Loop done, script done, delete the file
unlink $TEMPFILE

Get loop counter/index using for…of syntax in JavaScript

How about this

let numbers = [1,2,3,4,5]
numbers.forEach((number, index) => console.log(`${index}:${number}`))

Where array.forEach this method has an index parameter which is the index of the current element being processed in the array.

HTML/Javascript Button Click Counter

 
    <!DOCTYPE html>
<html>
<head>
<script>
     var clicks = 0;
    function myFunction() {

        clicks += 1;
        document.getElementById("demo").innerHTML = clicks;


    }
</script>
</head>
<body>

<p>Click the button to trigger a function.</p>

<button onclick="myFunction()">Click me</button>

<p id="demo"></p>

</body>
</html>

This should work for you :) Yes var should be used

How to count the number of words in a sentence, ignoring numbers, punctuation and whitespace?

str.split() without any arguments splits on runs of whitespace characters:

>>> s = 'I am having a very nice day.'
>>> 
>>> len(s.split())
7

From the linked documentation:

If sep is not specified or is None, a different splitting algorithm is applied: runs of consecutive whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace.

Counter in foreach loop in C#

Probably pointless, but...

foreach (var item in yourList.Select((Value, Index) => new { Value, Index }))
{
    Console.WriteLine("Value=" + item.Value + ", Index=" + item.Index);
}

How to sort Counter by value? - python

More general sorted, where the key keyword defines the sorting method, minus before numerical type indicates descending: 

>>> x = Counter({'a':5, 'b':3, 'c':7})
>>> sorted(x.items(), key=lambda k: -k[1])  # Ascending
[('c', 7), ('a', 5), ('b', 3)]

How to count the frequency of the elements in an unordered list?

 
seta = set(a)
b = [a.count(el) for el in seta]
a = list(seta) #Only if you really want it.

Android: Create spinner programmatically from array

This actually worked for me

    Spinner spinner = new Spinner(this);
    ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(
            this, android.R.layout.simple_spinner_item, spinnerArray);
    spinnerArrayAdapter.setDropDownViewResource( android.R.layout.simple_spinner_dropdown_item );

    spinner = (Spinner) findViewById( R.id.spinner );
    spinner.setAdapter(spinnerArrayAdapter);

jQuery vs. javascript?

Jquery like any other good JavaScript frameworks supplies you with functionality independent of browser platform wrapping all the intricacies, which you may not care about or don't want to care about.

I think using a framework is better instead of using pure JavaScript and doing all the stuff from scratch, unless you usage is very limited.

I definitely recommend JQuery!

Thanks

Run react-native on android emulator

On Windows 10 and Android Studio you can go in Android Studio to "File"->"Settings" in Settings then to "Appearance & Behavior" -> "System Settings" -> "Android SDK". In the Tab "SDK Tools" active:

  • "Android SDK Build-Tools .."
  • "Android Emulator"
  • "Android SDK Plattform-Tools"
  • "Android SDK Tools"

If all installed then you can start the Emulator in Android Studio with "Tools" -> "Android" -> "AVD Manager". If the Emulator run you can try "react-native run-android"

How can I reduce the waiting (ttfb) time

I have met the same problem. My project is running on the local server. I checked my php code. 

$db = mysqli_connect('localhost', 'root', 'root', 'smart');

I use localhost to connect to my local database. That maybe the cause of the problem which you're describing. You can modify your HOSTS file. Add the line

127.0.0.1 localhost.

How to use the ProGuard in Android Studio?

You're probably not actually signing the release build of the APK via the signing wizard. You can either build the release APK from the command line with the command:

./gradlew assembleRelease

or you can choose the release variant from the Build Variants view and build it from the GUI:

IDE main window showing Build Variants

Moving x-axis to the top of a plot in matplotlib

Use

ax.xaxis.tick_top()

to place the tick marks at the top of the image. The command

ax.set_xlabel('X LABEL')    
ax.xaxis.set_label_position('top')

affects the label, not the tick marks.

import matplotlib.pyplot as plt
import numpy as np
column_labels = list('ABCD')
row_labels = list('WXYZ')
data = np.random.rand(4, 4)
fig, ax = plt.subplots()
heatmap = ax.pcolor(data, cmap=plt.cm.Blues)

# put the major ticks at the middle of each cell
ax.set_xticks(np.arange(data.shape[1]) + 0.5, minor=False)
ax.set_yticks(np.arange(data.shape[0]) + 0.5, minor=False)

# want a more natural, table-like display
ax.invert_yaxis()
ax.xaxis.tick_top()

ax.set_xticklabels(column_labels, minor=False)
ax.set_yticklabels(row_labels, minor=False)
plt.show()

enter image description here

Create Carriage Return in PHP String?

Fragment PHP (in console Cloud9):

echo "\n";
echo "1: first_srt=1\nsecnd_srt=2\n";
echo "\n";
echo '2: first_srt=1\nsecnd_srt=2\n';
echo "\n";
echo "==============\n";
echo "\n";

resulting output:

  1: first_srt=1
  secnd_srt=2

  2: first_srt=1\nsecnd_srt=2\n
  ==============

Difference between 1 and 2: " versus '

Example: Communication between Activity and Service using Messaging

This is how I implemeted Activity->Service Communication: on my Activity i had 

private static class MyResultReciever extends ResultReceiver {
     /**
     * Create a new ResultReceive to receive results.  Your
     * {@link #onReceiveResult} method will be called from the thread running
     * <var>handler</var> if given, or from an arbitrary thread if null.
     *
     * @param handler
     */
     public MyResultReciever(Handler handler) {
         super(handler);
     }

     @Override
     protected void onReceiveResult(int resultCode, Bundle resultData) {
         if (resultCode == 100) {
             //dostuff
         }
     }

And then I used this to start my Service

protected void onCreate(Bundle savedInstanceState) {
MyResultReciever resultReciever = new MyResultReciever(handler);
        service = new Intent(this, MyService.class);
        service.putExtra("receiver", resultReciever);
        startService(service);
}

In my Service i had

public int onStartCommand(Intent intent, int flags, int startId) {
    if (intent != null)
        resultReceiver = intent.getParcelableExtra("receiver");
    return Service.START_STICKY;
}

Hope this Helps

Python extending with - using super() Python 3 vs Python 2

  • super() (without arguments) was introduced in Python 3 (along with __class__):

    super() -> same as super(__class__, self)

    so that would be the Python 2 equivalent for new-style classes:

    super(CurrentClass, self)

  • for old-style classes you can always use:

     class Classname(OldStyleParent):
    def __init__(self, *args, **kwargs):
        OldStyleParent.__init__(self, *args, **kwargs)

How to extend / inherit components?

Angular 2 version 2.3 was just released, and it includes native component inheritance. It looks like you can inherit and override whatever you want, except for templates and styles. Some references:

Finish all activities at a time

I was struggling with the same problem. Opening the about page and calling finish(); from there wasn't closing the app instead was going to previous activity and I wanted to close the app from the about page itself.

This is the code which worked for me:

Intent startMain = new Intent(Intent.ACTION_MAIN); 
startMain.addCategory(Intent.CATEGORY_HOME); 
startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
startActivity(startMain); 
finish();

Hope this helps.

Python3: ImportError: No module named '_ctypes' when using Value from module multiprocessing

This solved the same error for me on Debian:

sudo apt-get install libffi-dev

and compile again

Reference: issue31652

Difference between single and double quotes in Bash

The accepted answer is great. I am making a table that helps in quick comprehension of the topic. The explanation involves a simple variable a as well as an indexed array arr.

If we set

a=apple      # a simple variable
arr=(apple)  # an indexed array with a single element

and then echo the expression in the second column, we would get the result / behavior shown in the third column. The fourth column explains the behavior.

# Expression Result Comments
1 "$a" apple variables are expanded inside ""
2 '$a' $a variables are not expanded inside ''
3 "'$a'" 'apple' '' has no special meaning inside ""
4 '"$a"' "$a" "" is treated literally inside ''
5 '\'' invalid can not escape a ' within ''; use "'" or $'\'' (ANSI-C quoting)
6 "red$arocks" red $arocks does not expand $a; use ${a}rocks to preserve $a
7 "redapple$" redapple$ $ followed by no variable name evaluates to $
8 '\"' \" \ has no special meaning inside ''
9 "\'" \' \' is interpreted inside "" but has no significance for '
10 "\"" " \" is interpreted inside ""
11 "*" * glob does not work inside "" or ''
12 "\t\n" \t\n \t and \n have no special meaning inside "" or ''; use ANSI-C quoting
13 "`echo hi`" hi `` and $() are evaluated inside "" (backquotes are retained in actual output)
14 '`echo hi`' echo hi `` and $() are not evaluated inside '' (backquotes are retained in actual output)
15 '${arr[0]}' ${arr[0]} array access not possible inside ''
16 "${arr[0]}" apple array access works inside ""
17 $'$a\'' $a' single quotes can be escaped inside ANSI-C quoting
18 "$'\t'" $'\t' ANSI-C quoting is not interpreted inside ""
19 '!cmd' !cmd history expansion character '!' is ignored inside ''
20 "!cmd" cmd args expands to the most recent command matching "cmd"
21 $'!cmd' !cmd history expansion character '!' is ignored inside ANSI-C quotes

See also:

Python: 'break' outside loop

Because break cannot be used to break out of an if - it can only break out of loops. That's the way Python (and most other languages) are specified to behave.

What are you trying to do? Perhaps you should use sys.exit() or return instead?

Fit Image in ImageButton in Android

I want them to cover 75% of the button area.

Use android:padding="20dp" (adjust the padding as needed) to control how much the image takes up on the button.

but where as some images cover less area, some are too big to fit into the imageButton. How to programatically resize and show them?

Use a android:scaleType="fitCenter" to have Android scale the images, and android:adjustViewBounds="true" to have them adjust their bounds due to scaling.

All of these attributes can be set in code on each ImageButton at runtime. However, it is much easier to set and preview in xml in my opinion.

Also, do not use sp for anything other than text size, it is scaled depending on the text size preference the user sets, so your sp dimensions will be larger than your intended if the user has a "large" text setting. Use dp instead, as it is not scaled by the user's text size preference.

Here's a snippet of what each button should look like:

    <ImageButton
        android:id="@+id/button_topleft"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_marginBottom="5dp"
        android:layout_marginLeft="2dp"
        android:layout_marginRight="5dp"
        android:layout_marginTop="0dp"
        android:layout_weight="1"
        android:adjustViewBounds="true"
        android:padding="20dp"
        android:scaleType="fitCenter" />

Sample Button

How to view DB2 Table structure

I am running DB2/LINUXX8664 10.5.3 and describe select * from schema_name.table_name works for me.

However, describe table schema_name.table_name fails with this error:

SQL0100W No row was found for FETCH, UPDATE or DELETE; or the result of a query is an empty table. SQLSTATE=02000

Can you have multiline HTML5 placeholder text in a <textarea>?

With Vue.js:

<textarea name="story" :placeholder="'Enter story\n next line\n more'"></textarea>

Fastest way to compute entropy in Python

My favorite function for entropy is the following:

def entropy(labels):
    prob_dict = {x:labels.count(x)/len(labels) for x in labels}
    probs = np.array(list(prob_dict.values()))

    return - probs.dot(np.log2(probs))

I am still looking for a nicer way to avoid the dict -> values -> list -> np.array conversion. Will comment again if I found it.

How do I run a Python program in the Command Prompt in Windows 7?

It has taken me some effort looking for answers here, on the web, and and in the Python documentation, and testing on my own, to finally get my Python scripts working smoothly on my Windows machines (WinXP and Win7). So, I just blogged about it and am pasting that below in case it's useful to others. Sorry it's long, and feel free to improve it; I'm no expert.

[UPDATE: Python 3.3 now includes the Python Launcher for Windows, which allows you to type py (rather than python) to invoke the default interpreter, or py -2, py -3, py -2.7, etc. It also supports shebang lines, allowing the script itself to specify. For versions prior to 3.3, the launcher is available as a separate download. http://docs.python.org/3/whatsnew/3.3.html ]

Running Python scripts conveniently under Windows

Maybe you're creating your own Python scripts, or maybe someone has given you one for doing something with your data files. Say you've acquired a Python script and have saved it to "D:\my scripts\ApplyRE.py". You want to run it conveniently by either double-clicking it or typing it into the command line from any location, with the option of passing parameters to it like this (-o means "overwrite the output file if it already exists"): 

ApplyRE infile.txt outfile.txt -o

Say you also have a data file, "C:\some files\some lexicon.txt". The simplest option is to move the file or the script so they're in the same location, but that can get messy, so let's assume that they'll stay separate.

Making sure Windows can find the Python interpreter

After installing Python, verify that typing python into a command prompt works (and then type exit() to get back out of the Python interpreter). 

C:\>python
Python 3.2 (r32:88445, Feb 20 2011, 21:29:02) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
C:\>

If this doesn't work, you'll need to append something like ";C:\Python32" (without quotes) to the PATH environment variable. See PATHEXT below for instructions.

Associating Python with .py and .pyc

Verify that double-clicking on ApplyRE.py runs it. (It should also have a Python logo as its icon and be labeled "Python File", by the way.) If this isn't already done, right-click on a .py file, choose Open With, Choose Program, and check "Always use..." This association improves convenience but isn't strictly necessary--you can specify "python" every time you want to run a script, like this:

D:\my scripts>python ApplyRE.py lexicon-sample.txt -o
Running... Done.

Here's a very specific variation, which is optional unless you need to specify a different version of the interpreter.

D:\my scripts>c:\python32\python ApplyRE.py lexicon-sample.txt -o
Running... Done.

But that's a pain. Fortunately, once Python is installed, in the PATH, and associated with .py, then double-clicking a .py file or directly typing it as a command should work fine. Here, we seem to be running the script directly--it's nice and simple to run it on a sample file that's located in the "my scripts" folder along with the script.

D:\my scripts>ApplyRE.py lexicon-sample.txt -o
Running... Done.

Omitting the .py extension (editing PATHEXT)

To further reduce typing, you can tell Windows that .py (and perhaps .pyc files) are executable. To do this, right-click Computer and choose Properties, Advanced, Environment Variables, System Variables. Append ";.PY;.PYC" (without quotes) to the existing PATHEXT variable, or else create it if you're certan it doesn't exist yet. Close and reopen the command prompt. You should now be able to omit the .py (FYI, doing so would cause ApplyRE.exe or ApplyRE.bat to run instead, if one existed).

D:\my scripts>ApplyRE lexicon-sample.txt -o
Running... Done.

Adding scripts to the system PATH

If you're going to use your scripts often from the command prompt (it's less important if doing so via using BAT files), then you'll want to add your scripts' folder to the system PATH. (Next to PATHEXT you should see a PATH variable; append ";D:\my scripts" to it, without quotes.) This way you can run a script from some other location against the files in current location, like this:

C:\some files>ApplyRE "some lexicon.txt" "some lexicon OUT.txt" -o
Running... Done.

Success! That's pretty much all you need to do to streamline the command-line.

Running directly without tweaking the PATH

If you're a fast typist or don't mind creating a batch file for each situation, you can specify full paths (for the script, or for the parameters) instead of tweaking PATH.

C:\some files>"d:\my scripts\ApplyRE.py" "some lexicon.txt" "some lexicon OUT.txt" -o
Running... Done.
C:\some files>d:
D:\>cd "my scripts"
D:\my scripts>ApplyRE.py "c:\some files\some lexicon.txt" "c:\some files\some lexicon OUT.txt" -o
Running... Done.

Creating shortcuts or batch files

If .py is associated with an installed Python, you can just double-click ApplyRE.py to run it, but the console may appear and disappear too quickly to read its output (or failure!). And to pass parameters, you'd need to first do one of the following. (a) Right-click and create a shortcut. Right-click the shortcut to edit properties and append parameters to Target. (b) Create a batch file--a plain text file with a distinct name such as ApplyRErun.bat. This option is probably better because you can ask it to pause so you can see the output. Here is a sample BAT file's contents, written to be located and run from c:\some files .

python "d:\my scripts\ApplyRE.py" "some lexicon.txt" "some lexicon OUT.txt" -o
pause

Advanced: appending to PYTHONPATH

This usually isn't necessary, but one other environment variable that may be relevant is PYTHONPATH. If we were to append d:\my scripts to that variable, then other Python scripts in other locations could make use of those via import statements.

Invalid argument supplied for foreach()

More concise extension of @Kris's code

function secure_iterable($var)
{
    return is_iterable($var) ? $var : array();
}

foreach (secure_iterable($values) as $value)
{
     //do stuff...
}

especially for using inside template code 

<?php foreach (secure_iterable($values) as $value): ?>
    ...
<?php endforeach; ?>

dlib installation on Windows 10

After spending a lot of time, this comment gave me the right result.

https://github.com/ageitgey/face_recognition/issues/802#issuecomment-544232494

  1. Download Python 3.6.8 and install, make sure you add it to PATH.

  2. Install NumPy, scipy, matplotlib and pandas in your pc/laptop with this command in command prompt:-

    pip install numpy

    pip install scipy

    pip install matplotlib

    pip install pandas

  3. Go to https://pypi.org/project/wheel/#files and right click on filename wheel-0.33.6-py2.py3-none-any.whl (21.6 kB) and copy link address. Then go to your pc/laptop, open command prompt and write this command "python -m pip install" after this command space first then paste the link copied. After install successful go to next step.

  4. Then go this link, https://pypi.org/simple/dlib/ and right click on filename "dlib-19.8.1-cp36-cp36m-win_amd64.whl" then copy link address. Then open command prompt and do the same as step 2 which is, write this command "python -m pip install" after this command space first then paste the link copied. then the dlib will be installed successfully.

  5. After that, type python and enter, then type import dlib to check dlib is installed perfectly. the you can proceed to install face recognition.py which suite for python 3.6.

Remove border from buttons

You can also try background:none;border:0px to buttons.

also the css selectors are div#yes button{..} and div#no button{..} . hopes it helps

What is a "callable"?

A Callable is an object that has the __call__ method. This means you can fake callable functions or do neat things like Partial Function Application where you take a function and add something that enhances it or fills in some of the parameters, returning something that can be called in turn (known as Currying in functional programming circles).

Certain typographic errors will have the interpreter attempting to call something you did not intend, such as (for example) a string. This can produce errors where the interpreter attempts to execute a non-callable application. You can see this happening in a python interpreter by doing something like the transcript below.

[nigel@k9 ~]$ python
Python 2.5 (r25:51908, Nov  6 2007, 15:55:44) 
[GCC 4.1.2 20070925 (Red Hat 4.1.2-27)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 'aaa'()    # <== Here we attempt to call a string.
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable
>>>

How to set selected item of Spinner by value, not by position?

There is actually a way to get this using an index search on the AdapterArray and all this can be done with reflection. I even went one step further as I had 10 Spinners and wanted to set them dynamically from my database and the database holds the value only not the text as the Spinner actually changes week to week so the value is my id number from the database.

 // Get the JSON object from db that was saved, 10 spinner values already selected by user
 JSONObject json = new JSONObject(string);
 JSONArray jsonArray = json.getJSONArray("answer");

 // get the current class that Spinner is called in 
 Class<? extends MyActivity> cls = this.getClass();

 // loop through all 10 spinners and set the values with reflection             
 for (int j=1; j< 11; j++) {
      JSONObject obj = jsonArray.getJSONObject(j-1);
      String movieid = obj.getString("id");

      // spinners variable names are s1,s2,s3...
      Field field = cls.getDeclaredField("s"+ j);

      // find the actual position of value in the list     
      int datapos = indexedExactSearch(Arrays.asList(Arrays.asList(this.data).toArray()), "value", movieid) ;
      // find the position in the array adapter
      int pos = this.adapter.getPosition(this.data[datapos]);

      // the position in the array adapter
      ((Spinner)field.get(this)).setSelection(pos);

}

Here is the indexed search you can use on almost any list as long as the fields are on top level of object.

    /**
 * Searches for exact match of the specified class field (key) value within the specified list.
 * This uses a sequential search through each object in the list until a match is found or end
 * of the list reached.  It may be necessary to convert a list of specific objects into generics,
 * ie: LinkedList&ltDevice&gt needs to be passed as a List&ltObject&gt or Object[&nbsp] by using 
 * Arrays.asList(device.toArray(&nbsp)).
 * 
 * @param list - list of objects to search through
 * @param key - the class field containing the value
 * @param value - the value to search for
 * @return index of the list object with an exact match (-1 if not found)
 */
public static <T> int indexedExactSearch(List<Object> list, String key, String value) {
    int low = 0;
    int high = list.size()-1;
    int index = low;
    String val = "";

    while (index <= high) {
        try {
            //Field[] c = list.get(index).getClass().getDeclaredFields();
            val = cast(list.get(index).getClass().getDeclaredField(key).get(list.get(index)) , "NONE");
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

        if (val.equalsIgnoreCase(value))
            return index; // key found

        index = index + 1;
    }

    return -(low + 1);  // key not found return -1
}

Cast method which can be create for all primitives here is one for string and int.

        /**
 *  Base String cast, return the value or default
 * @param object - generic Object
 * @param defaultValue - default value to give if Object is null
 * @return - returns type String
 */
public static String cast(Object object, String defaultValue) {
    return (object!=null) ? object.toString() : defaultValue;
}


    /**
 *  Base integer cast, return the value or default
 * @param object - generic Object
 * @param defaultValue - default value to give if Object is null
 * @return - returns type integer
 */
public static int cast(Object object, int defaultValue) { 
    return castImpl(object, defaultValue).intValue();
}

    /**
 *  Base cast, return either the value or the default
 * @param object - generic Object
 * @param defaultValue - default value to give if Object is null
 * @return - returns type Object
 */
public static Object castImpl(Object object, Object defaultValue) {
    return object!=null ? object : defaultValue;
}

How do I set the default schema for a user in MySQL

There is no default database for user. There is default database for current session.

You can get it using DATABASE() function -

SELECT DATABASE();

And you can set it using USE statement -

USE database1;

You should set it manually - USE db_name, or in the connection string.

Installing Tomcat 7 as Service on Windows Server 2008

There are a lot of answers here, but many overlook a few points. I ran into the same issue and it was likely due to a combination of being a complete neophyte when it comes to tomcat. Even more I am rather new to web servers in general. I consider myself somewhat proficient user of windows, but I guess not proficient enough. In particular I don't work with services too much.

I did not have a startup.bat or any bat files. I only downloaded the 32-bit/64-bit Windows Service Installer. The bin that is created for that download is small - only 4 files. My colleagues were surprised that I did not have a catalina.bat etc... and I was too. Only the below four files in the bin. And no %CATALINA_HOME% or %TOMCAT_HOME% etc...

bootstrap.jar
tomcat-juli.jar
Tomcat7.exe
Tomcat7w.exe

With this setup I had some frustrations as setting parameters is done via the gui widget - very helpful I might add.

So nearly all the answers I have perused were not immediately applicable as many said, "go to bin and issue the startup.bat file" I am a neophyte but not so much to not be able to look into the bin and start such a file it is existed!

For my simple purposes (again remember that I am a neophyte at tomcat and even web servers) all I wanted to do was to be able to startup and shutdown the tomcat server from a cmd prompt window. Nothing too heavy duty. I am embarrassed to say how simple it is. It is probably evident to anyone with a shred of experience with services and such.

To Start server: <Tomcat Root>/bin>Tomcat7.exe start
To Stop server: <Tomcat Root>/bin>Tomcat7.exe stop

Found here - http://crunchify.com/how-to-start-stop-apache-tomcat-server-via-command-line-setup-as-windows-service/

I did not realize there was a separate download the 64-bit Windows zip file that has a tomcat server and all the standard array of cmd line tomcat management tools. This zip file has all the common startup/shutdown scripts, batch files for windows, including catalina.bat/.sh etc... Then all the above answers make sense and are rather trivial.

Remember I am a neophyte when it comes to tomcat and web servers. It appears these two downloads are somewhat mutually exclusive in the sense that if I download and install the 32-bit/64-bit Windows Service Installer version and the 64-bit Windows zip file the startup.bat file in the 64-bit Windows zip file version will not run or interact with the 32-bit/64-bit Windows Service Installer tomcat instance. But I am not sure about this point.

Getting all types that implement an interface

This worked for me (if you wish you could exclude system types in the lookup):

Type lookupType = typeof (IMenuItem);
IEnumerable<Type> lookupTypes = GetType().Assembly.GetTypes().Where(
        t => lookupType.IsAssignableFrom(t) && !t.IsInterface);

Round up to Second Decimal Place in Python

The python round function could be rounding the way not you expected.

You can be more specific about the rounding method by using Decimal.quantize

eg.

from decimal import Decimal, ROUND_HALF_UP
res = Decimal('0.25').quantize(Decimal('0.0'), rounding=ROUND_HALF_UP)
print(res) 
# prints 0.3

More reference:

https://gist.github.com/jackiekazil/6201722

Alternate output format for psql

I just needed to spend more time staring at the documentation. This command:

\x on

will do exactly what I wanted. Here is some sample output:

select * from dda where u_id=24 and dda_is_deleted='f';
-[ RECORD 1 ]------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
dda_id             | 1121
u_id               | 24
ab_id              | 10304
dda_type           | CHECKING
dda_status         | PENDING_VERIFICATION
dda_is_deleted     | f
dda_verify_op_id   | 44938
version            | 2
created            | 2012-03-06 21:37:50.585845
modified           | 2012-03-06 21:37:50.593425
c_id               | 
dda_nickname       | 
dda_account_name   | 
cu_id              | 1
abd_id             |

FloatingActionButton example with Support Library

FloatingActionButton extends ImageView. So, it's simple as like introducing an ImageView in your layout. Here is an XML sample.

<android.support.design.widget.FloatingActionButton   xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/somedrawable"
    android:layout_gravity="right|bottom"
    app:borderWidth="0dp"
    app:rippleColor="#ffffff"/>

app:borderWidth="0dp" is added as a workaround for elevation issues.

Where can I download Spring Framework jars without using Maven?

Please edit to keep this list of mirrors current

I found this maven repo where you could download from directly a zip file containing all the jars you need.

Alternate solution: Maven

The solution I prefer is using Maven, it is easy and you don't have to download each jar alone. You can do it with the following steps:

  1. Create an empty folder anywhere with any name you prefer, for example spring-source

  2. Create a new file named pom.xml

  3. Copy the xml below into this file

  4. Open the spring-source folder in your console

  5. Run mvn install

  6. After download finished, you'll find spring jars in /spring-source/target/dependencies

    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>spring-source-download</groupId>
  <artifactId>SpringDependencies</artifactId>
  <version>1.0</version>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>3.2.4.RELEASE</version>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-dependency-plugin</artifactId>
        <version>2.8</version>
        <executions>
          <execution>
            <id>download-dependencies</id>
            <phase>generate-resources</phase>
            <goals>
              <goal>copy-dependencies</goal>
            </goals>
            <configuration>
              <outputDirectory>${project.build.directory}/dependencies</outputDirectory>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

Also, if you need to download any other spring project, just copy the dependency configuration from its corresponding web page.

For example, if you want to download Spring Web Flow jars, go to its web page, and add its dependency configuration to the pom.xml dependencies, then run mvn install again.

<dependency>
  <groupId>org.springframework.webflow</groupId>
  <artifactId>spring-webflow</artifactId>
  <version>2.3.2.RELEASE</version>
</dependency>

Converting a string to int in Groovy

Several ways to achieve this. Examples are as below

a. return "22".toInteger()
b. if("22".isInteger()) return "22".toInteger()
c. return "22" as Integer()
d. return Integer.parseInt("22")

Hope this helps

What 'additional configuration' is necessary to reference a .NET 2.0 mixed mode assembly in a .NET 4.0 project?

I was experiencing this same error, and spent forever adding the suggested startup statements to various config files in my solution, attempting to isolate the framework mismatch. Nothing worked. I also added startup information to my XML schemas. That didn't help either. Looking at the actual file that was causing the problem (which would only say it was "moved or deleted") revealed it was actually the License Compiler (LC).

Deleting the offending licenses.licx file seems to have fixed the problem.

Java - sending HTTP parameters via POST method easily

i have read above answers and have created a utility class to simplify HTTP request. i hope it will help you.

Method Call

  // send params with Hash Map
    HashMap<String, String> params = new HashMap<String, String>();
    params.put("email","[email protected]");
    params.put("password","12345");

    //server url
    String url = "http://www.example.com";

    // static class "HttpUtility" with static method "newRequest(url,method,callback)"
    HttpUtility.newRequest(url,HttpUtility.METHOD_POST,params, new HttpUtility.Callback() {
        @Override
        public void OnSuccess(String response) {
        // on success
           System.out.println("Server OnSuccess response="+response);
        }
        @Override
        public void OnError(int status_code, String message) {
        // on error
              System.out.println("Server OnError status_code="+status_code+" message="+message);
        }
    });

Utility Class

import java.io.*;
import java.net.*;
import java.util.HashMap;
import java.util.Map;
import static java.net.HttpURLConnection.HTTP_OK;

public class HttpUtility {

 public static final int METHOD_GET = 0; // METHOD GET
 public static final int METHOD_POST = 1; // METHOD POST

 // Callback interface
 public interface Callback {
  // abstract methods
  public void OnSuccess(String response);
  public void OnError(int status_code, String message);
 }
 // static method
 public static void newRequest(String web_url, int method, HashMap < String, String > params, Callback callback) {

  // thread for handling async task
  new Thread(new Runnable() {
   @Override
   public void run() {
    try {
     String url = web_url;
     // write GET params,append with url
     if (method == METHOD_GET && params != null) {
      for (Map.Entry < String, String > item: params.entrySet()) {
       String key = URLEncoder.encode(item.getKey(), "UTF-8");
       String value = URLEncoder.encode(item.getValue(), "UTF-8");
       if (!url.contains("?")) {
        url += "?" + key + "=" + value;
       } else {
        url += "&" + key + "=" + value;
       }
      }
     }

     HttpURLConnection urlConnection = (HttpURLConnection) new URL(url).openConnection();
     urlConnection.setUseCaches(false);
     urlConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); // handle url encoded form data
     urlConnection.setRequestProperty("charset", "utf-8");
     if (method == METHOD_GET) {
      urlConnection.setRequestMethod("GET");
     } else if (method == METHOD_POST) {
      urlConnection.setDoOutput(true); // write POST params
      urlConnection.setRequestMethod("POST");
     }

     //write POST data 
     if (method == METHOD_POST && params != null) {
      StringBuilder postData = new StringBuilder();
      for (Map.Entry < String, String > item: params.entrySet()) {
       if (postData.length() != 0) postData.append('&');
       postData.append(URLEncoder.encode(item.getKey(), "UTF-8"));
       postData.append('=');
       postData.append(URLEncoder.encode(String.valueOf(item.getValue()), "UTF-8"));
      }
      byte[] postDataBytes = postData.toString().getBytes("UTF-8");
      urlConnection.setRequestProperty("Content-Length", String.valueOf(postDataBytes.length));
      urlConnection.getOutputStream().write(postDataBytes);

     }
     // server response code
     int responseCode = urlConnection.getResponseCode();
     if (responseCode == HTTP_OK && callback != null) {
      BufferedReader reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
      StringBuilder response = new StringBuilder();
      String line;
      while ((line = reader.readLine()) != null) {
       response.append(line);
      }
      // callback success
      callback.OnSuccess(response.toString());
      reader.close(); // close BufferReader
     } else if (callback != null) {
      // callback error
      callback.OnError(responseCode, urlConnection.getResponseMessage());
     }

     urlConnection.disconnect(); // disconnect connection
    } catch (IOException e) {
     e.printStackTrace();
     if (callback != null) {
      // callback error
      callback.OnError(500, e.getLocalizedMessage());
     }
    }
   }
  }).start(); // start thread
 }
}

invalid byte sequence for encoding "UTF8"

Well I was facing the same problem. And what solved my problem is this:

In excel click on Save as. From save as type, choose .csv Click on Tools. Then choose web options from drop down list. Under Encoding tab, save the document as Unicode(UTF-8). Click OK. Save the file. DONE !

How do I set up the database.yml file in Rails?

The database.yml is a file that is created with new rails applications in /config and defines the database configurations that your application will use in different environments. Read this for details.

Example database.yml:

development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000

test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

production:
  adapter: mysql
  encoding: utf8
  database: your_db
  username: root
  password: your_pass
  socket: /tmp/mysql.sock
  host: your_db_ip     #defaults to 127.0.0.1
  port: 3306

A JOIN With Additional Conditions Using Query Builder or Eloquent

The sql query sample like this

LEFT JOIN bookings  
    ON rooms.id = bookings.room_type_id
    AND (bookings.arrival = ?
        OR bookings.departure = ?)

Laravel join with multiple conditions 

->leftJoin('bookings', function($join) use ($param1, $param2) {
    $join->on('rooms.id', '=', 'bookings.room_type_id');
    $join->on(function($query) use ($param1, $param2) {
        $query->on('bookings.arrival', '=', $param1);
        $query->orOn('departure', '=',$param2);
    });
})

Multiline editing in Visual Studio Code

As of April 2018 (version 1.23) you can now also use the middle mouse button to multiline select / box select.

instantiate a class from a variable in PHP?

 
class Test {
    public function yo() {
        return 'yoes';
    }
}

$var = 'Test';

$obj = new $var();
echo $obj->yo(); //yoes

How to cast int to enum in C++?

Spinning off the closing question, "how do I convert a to type Test::A" rather than being rigid about the requirement to have a cast in there, and answering several years late only because this seems to be a popular question and nobody else has mentioned the alternative, per the C++11 standard:

5.2.9 Static cast

... an expression e can be explicitly converted to a type T using a static_cast of the form static_cast<T>(e) if the declaration T t(e); is well-formed, for some invented temporary variable t (8.5). The effect of such an explicit conversion is the same as performing the declaration and initialization and then using the temporary variable as the result of the conversion.

Therefore directly using the form t(e) will also work, and you might prefer it for neatness:

auto result = Test(a);

Multiple try codes in one block

You can use fuckit module.
Wrap your code in a function with @fuckit decorator:

@fuckit
def func():
    code a
    code b #if b fails, it should ignore, and go to c.
    code c #if c fails, go to d
    code d

How to add property to object in PHP >= 5.3 strict mode without generating error

I always use this way:

$foo = (object)null; //create an empty object
$foo->bar = "12345";

echo $foo->bar; //12345

Adb install failure: INSTALL_CANCELED_BY_USER

Turn off Miui Optimizations on Developer Settings, then Restart the phone. it worked for me. Settings > Additional Settings > Developer Options > MIUI Optimization

What’s the best way to get an HTTP response code from a URL?

Here's an httplib solution that behaves like urllib2. You can just give it a URL and it just works. No need to mess about splitting up your URLs into hostname and path. This function already does that.

import httplib
import socket
def get_link_status(url):
  """
    Gets the HTTP status of the url or returns an error associated with it.  Always returns a string.
  """
  https=False
  url=re.sub(r'(.*)#.*$',r'\1',url)
  url=url.split('/',3)
  if len(url) > 3:
    path='/'+url[3]
  else:
    path='/'
  if url[0] == 'http:':
    port=80
  elif url[0] == 'https:':
    port=443
    https=True
  if ':' in url[2]:
    host=url[2].split(':')[0]
    port=url[2].split(':')[1]
  else:
    host=url[2]
  try:
    headers={'User-Agent':'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:26.0) Gecko/20100101 Firefox/26.0',
             'Host':host
             }
    if https:
      conn=httplib.HTTPSConnection(host=host,port=port,timeout=10)
    else:
      conn=httplib.HTTPConnection(host=host,port=port,timeout=10)
    conn.request(method="HEAD",url=path,headers=headers)
    response=str(conn.getresponse().status)
    conn.close()
  except socket.gaierror,e:
    response="Socket Error (%d): %s" % (e[0],e[1])
  except StandardError,e:
    if hasattr(e,'getcode') and len(e.getcode()) > 0:
      response=str(e.getcode())
    if hasattr(e, 'message') and len(e.message) > 0:
      response=str(e.message)
    elif hasattr(e, 'msg') and len(e.msg) > 0:
      response=str(e.msg)
    elif type('') == type(e):
      response=e
    else:
      response="Exception occurred without a good error message.  Manually check the URL to see the status.  If it is believed this URL is 100% good then file a issue for a potential bug."
  return response

how to refresh Select2 dropdown menu after ajax loading different content?

Select 3.*

Please see Update select2 data without rebuilding the control as this may be a duplicate. Another way is to destroy and then recreate the select2 element.

$("#dropdown").select2("destroy");

$("#dropdown").select2();

If you are having problems with resetting the state/region on country change try clearing the current value with 

$("#dropdown").select2("val", "");

You can view the documentation here http://ivaynberg.github.io/select2/ that outlines nearly/all features. Select2 supports events such as change that can be used to update the subsequent dropdowns.

$("#dropdown").on("change", function(e) {});

Select 4.* Update

You can now update the data/list without rebuilding the control using:

fooBarDropdown.select2({
    data: fromAccountData
});

How do you grep a file and get the next 5 lines

Some awk version.

awk '/19:55/{c=5} c-->0'
awk '/19:55/{c=5} c && c--'

When pattern found, set c=5
If c is true, print and decrease number of c

Wait until boolean value changes it state

You need a mechanism which avoids busy-waiting. The old wait/notify mechanism is fraught with pitfalls so prefer something from the java.util.concurrent library, for example the CountDownLatch:

public final CountDownLatch latch = new CountDownLatch(1);

public void run () {
  latch.await();
  ...
}

And at the other side call

yourRunnableObj.latch.countDown();

However, starting a thread to do nothing but wait until it is needed is still not the best way to go. You could also employ an ExecutorService to which you submit as a task the work which must be done when the condition is met.

How do I create a chart with multiple series using different X values for each series?

You need to use the Scatter chart type instead of Line. That will allow you to define separate X values for each series.

Java Comparator class to sort arrays

[...] How should Java Comparator class be declared to sort the arrays by their first elements in decreasing order [...]

Here's a complete example using Java 8:

import java.util.*;

public class Test {

    public static void main(String args[]) {

        int[][] twoDim = { {1, 2}, {3, 7}, {8, 9}, {4, 2}, {5, 3} };

        Arrays.sort(twoDim, Comparator.comparingInt(a -> a[0])
                                      .reversed());

        System.out.println(Arrays.deepToString(twoDim));
    }
}

Output:

[[8, 9], [5, 3], [4, 2], [3, 7], [1, 2]]

For Java 7 you can do:

Arrays.sort(twoDim, new Comparator<int[]>() {
    @Override
    public int compare(int[] o1, int[] o2) {
        return Integer.compare(o2[0], o1[0]);
    }
});

If you unfortunate enough to work on Java 6 or older, you'd do:

Arrays.sort(twoDim, new Comparator<int[]>() {
    @Override
    public int compare(int[] o1, int[] o2) {
        return ((Integer) o2[0]).compareTo(o1[0]);
    }
});

initializing strings as null vs. empty string

There are no gotchas. The default construction of std::string is "". But you cannot compare a string to NULL. The closest you can get is to check whether the string is empty or not, using the std::string::empty method..

How to keep environment variables when using sudo

If you have the need to keep the environment variables in a script you can put your command in a here document like this. Especially if you have lots of variables to set things look tidy this way.

# prepare a script e.g. for running maven
runmaven=/tmp/runmaven$$
# create the script with a here document 
cat << EOF > $runmaven
#!/bin/bash
# run the maven clean with environment variables set
export ANT_HOME=/usr/share/ant
export MAKEFLAGS=-j4
mvn clean install
EOF
# make the script executable
chmod +x $runmaven
# run it
sudo $runmaven
# remove it or comment out to keep
rm $runmaven

Difference between == and ===

In Swift we have === simbol which means is both objects are referring to the same reference same address

class SomeClass {
var a: Int;

init(_ a: Int) {
    self.a = a
}

}

var someClass1 = SomeClass(4)
var someClass2 = SomeClass(4)
someClass1 === someClass2 // false
someClass2 = someClass1
someClass1 === someClass2 // true

How to convert int to QString?

Use QString::number():

int i = 42;
QString s = QString::number(i);

How to fire a button click event from JavaScript in ASP.NET

You can just place this line in a JavaScript function:

__doPostBack('btnSubmit','OnClick');

Or do something like this:

$('#btnSubmit').trigger('click');

Objective-C for Windows

First of all, forget about GNUStep tools. Neither ProjectManager nor ProjectCenter can be called an IDE. With all due respect, it looks like guys from GNUStep project are stuck in the late 80-s (which is when NeXTSTEP first appeared).

Vim

ctags support Objective-C since r771 (be sure to pick the pre-release 5.9 version and add --langmap=ObjectiveC:.m.h to the command line, see here), so you'll have decent code completion/tag navigation.

Here's a short howto on adding Objective-C support to Vim tagbar plugin.

Emacs

The same applies to etags shipped with modern Emacsen, so you can start with Emacs Objective C Mode. YASnippet will provide useful templates:

YASnippet objc-mode

and if you want something more intelligent than the basic tags-based code completion, take a look at this question.

Eclipse

CDT supports Makefile-based projects:

enter image description here

-- so technically you can build your Objective-C projects out of the box (on Windows, you'll need the Cygwin or MinGW toolchain). The only problem is the code editor which will report plenty of errors against what it thinks is a pure C code (on-the-fly code checking can be turned off, but still...). If you want proper syntax highlighting, you can add Eclim to your Eclipse and enjoy all the good features of both Eclipse and Vim (see above).

Another promising Eclipse plugin is Colorer, but it doesn't support Objective-C as of yet. Feel free to file a feature request though.

SlickEdit

SlickEdit, among other features of a great IDE, does support Objective-C. While it is fairly complex to learn (not as complex as Emacs though), I believe this is your best option provided you don't mind purchasing it (the price is quite affordable).

Additionally, it has an Eclipse plugin which can be used as an alternative to the stand-alone editor.

KDevelop

Rumor has it there exists a KDevelop patch (15 year old, but who cares?). I personally don't think KDevelop is feature-superior compared to Emacsen, so I wouldn't bother trying it.

The above also applies to Objective-C development on Linux, since all of the tools mentioned are more or less portable.

How to overwrite the previous print to stdout in python?

I'm a bit surprised nobody is using the backspace character. Here's one that uses it.

import sys
import time

secs = 1000

while True:
    time.sleep(1)  #wait for a full second to pass before assigning a second
    secs += 1  #acknowledge a second has passed

    sys.stdout.write(str(secs))

    for i in range(len(str(secs))):
        sys.stdout.write('\b')

How do you calculate log base 2 in Java for integers?

you can use the identity

            log[a]x
 log[b]x = ---------
            log[a]b

so this would be applicable for log2.

            log[10]x
 log[2]x = ----------
            log[10]2

just plug this into the java Math log10 method....

http://mathforum.org/library/drmath/view/55565.html

Oracle SQL update based on subquery between two tables

There are two ways to do what you are trying

One is a Multi-column Correlated Update

UPDATE PRODUCTION a
SET (name, count) = (
  SELECT name, count
  FROM STAGING b
  WHERE a.ID = b.ID);

DEMO

You can use merge

MERGE INTO PRODUCTION a
USING ( select id, name, count 
          from STAGING ) b
ON ( a.id = b.id )
WHEN MATCHED THEN 
UPDATE SET  a.name = b.name,
            a.count = b.count

DEMO

How to get the new value of an HTML input after a keypress has modified it?

You can try this code (requires jQuery):

<html>
<head>
    <script type="text/javascript" src="jquery.js"></script>
    <script type="text/javascript">
        $(document).ready(function() {
            $('#foo').keyup(function(e) {
                var v = $('#foo').val();
                $('#debug').val(v);
            })
        });
    </script>
</head>
<body>
    <form>
        <input type="text" id="foo" value="bar"><br>
        <textarea id="debug"></textarea>
    </form>
</body>
</html>

Why doesn't JavaScript support multithreading?

However you can use eval function to bring concurrency TO SOME EXTENT

/* content of the threads to be run */
var threads = [
        [
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');",
            "document.write('Foo <br/>');"
        ],
        [
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');",
            "document.write('Bar <br/>');"
        ]
    ];

window.onload = function() {
    var lines = 0, quantum = 3, max = 0;

    /* get the longer thread length */
    for(var i=0; i<threads.length; i++) {
        if(max < threads[i].length) {
            max = threads[i].length;
        }
    }

    /* execute them */
    while(lines < max) {
        for(var i=0; i<threads.length; i++) {
            for(var j = lines; j < threads[i].length && j < (lines + quantum); j++) {
                eval(threads[i][j]);
            }
        }
        lines += quantum;
    }
}

Javascript "Not a Constructor" Exception while creating objects

For my project, the problem turned out to be a circular reference created by the require() calls:

y.js:
var x = require("./x.js");
var y = function() { console.log("result is " + x(); }
module.exports = y;

x.js:
var y = require("./y.js");
var my_y = new y(); // <- TypeError: y is not a constructor
var x = function() { console.log("result is " + my_y; }
module.exports = x;

The reason is that when it is attempting to initialize y, it creates a temporary "y" object (not class, object!) in the dependency system that is somehow not yet a constructor. Then, when x.js is finished being defined, it can continue making y a constructor. Only, x.js has an error in it where it tries to use the non-constructor y.

Is there any difference between DECIMAL and NUMERIC in SQL Server?

Joakim Backman's answer is specific, but this may bring additional clarity to it.

There is a minor difference. As per SQL For Dummies, 8th Edition (2013):

The DECIMAL data type is similar to NUMERIC. ... The difference is that your implementation may specify a precision greater than what you specify — if so, the implementation uses the greater precision. If you do not specify precision or scale, the implementation uses default values, as it does with the NUMERIC type.

It seems that the difference on some implementations of SQL is in data integrity. DECIMAL allows overflow from what is defined based on some system defaults, where as NUMERIC does not.

Getting android.content.res.Resources$NotFoundException: exception even when the resource is present in android

For my condition the cause was taking int parameter for TextView. Let me show an example

int i = 5;
myTextView.setText(i);

gets the error info above.

This can be fixed by converting int to String like this

myTextView.setText(String.valueOf(i));

As you write int, it expects a resource not the text that you are writing. So be careful on setting an int as a String in Android.

Best practice for localization and globalization of strings and labels

As far as I know, there's a good library called localeplanet for Localization and Internationalization in JavaScript. Furthermore, I think it's native and has no dependencies to other libraries (e.g. jQuery)

Here's the website of library: http://www.localeplanet.com/

Also look at this article by Mozilla, you can find very good method and algorithms for client-side translation: http://blog.mozilla.org/webdev/2011/10/06/i18njs-internationalize-your-javascript-with-a-little-help-from-json-and-the-server/

The common part of all those articles/libraries is that they use a i18n class and a get method (in some ways also defining an smaller function name like _) for retrieving/converting the key to the value. In my explaining the key means that string you want to translate and the value means translated string.
Then, you just need a JSON document to store key's and value's.

For example:

var _ = document.webL10n.get;
alert(_('test'));

And here the JSON:

{ test: "blah blah" }

I believe using current popular libraries solutions is a good approach.

How do I get the selected element by name and then get the selected value from a dropdown using jQuery?

MrOBrian's answer shows why your current code doesn't work, with the missing trailing ] and quotes, but here's an easier way to make it work:

onchange='mySelectHandler(this)'

And then:

function mySelectHandler(el){
     var mySelect = $(el)
     // get selected value
     alert ("selected " + mySelect.val())
  }

Or better still, remove the inline event handler altogether and bind the event handler with jQuery:

$('select[name="a[b]"]').change(function() {
    var mySelect = $(this);
    alert("selected " mySelect.val());
});

That last would need to be in a document.ready handler or in a script block that appears after the select element. If you want to run the same function for other selects simply change the selector to something that applies to all, e.g., all selects would be $('select'), or all with a particular class would be $('select.someClass').

How can I get a specific field of a csv file?

 
#!/usr/bin/env python
"""Print a field specified by row, column numbers from given csv file.

USAGE:
    %prog csv_filename row_number column_number
"""
import csv
import sys

filename = sys.argv[1]
row_number, column_number = [int(arg, 10)-1 for arg in sys.argv[2:])]

with open(filename, 'rb') as f:
     rows = list(csv.reader(f))
     print rows[row_number][column_number]

Example

$ python print-csv-field.py input.csv 2 2
ddddd

Note: list(csv.reader(f)) loads the whole file in memory. To avoid that you could use itertools:

import itertools
# ...
with open(filename, 'rb') as f:
     row = next(itertools.islice(csv.reader(f), row_number, row_number+1))
     print row[column_number]

How do I import an existing Java keystore (.jks) file into a Java installation?

to load a KeyStore, you'll need to tell it the type of keystore it is (probably jceks), provide an inputstream, and a password. then, you can load it like so:

KeyStore ks  = KeyStore.getInstance(TYPE_OF_KEYSTORE);
ks.load(new FileInputStream(PATH_TO_KEYSTORE), PASSWORD);

this can throw a KeyStoreException, so you can surround in a try block if you like, or re-throw. Keep in mind a keystore can contain multiple keys, so you'll need to look up your key with an alias, here's an example with a symmetric key:

SecretKeyEntry entry = (KeyStore.SecretKeyEntry)ks.getEntry(SOME_ALIAS,new KeyStore.PasswordProtection(SOME_PASSWORD));
SecretKey someKey = entry.getSecretKey();

Using CMake with GNU Make: How can I see the exact commands?

I was trying something similar to ensure the -ggdb flag was present.

Call make in a clean directory and grep the flag you are looking for. Looking for debug rather than ggdb I would just write.

make VERBOSE=1 | grep debug

The -ggdb flag was obscure enough that only the compile commands popped up.

Update Row if it Exists Else Insert Logic with Entity Framework

The magic happens when calling SaveChanges() and depends on the current EntityState. If the entity has an EntityState.Added, it will be added to the database, if it has an EntityState.Modified, it will be updated in the database. So you can implement an InsertOrUpdate() method as follows:

public void InsertOrUpdate(Blog blog) 
{ 
    using (var context = new BloggingContext()) 
    { 
        context.Entry(blog).State = blog.BlogId == 0 ? 
                                   EntityState.Added : 
                                   EntityState.Modified; 

        context.SaveChanges(); 
    } 
}

More about EntityState

If you can't check on Id = 0 to determine if it's a new entity or not, check the answer of Ladislav Mrnka.

Replace all non-alphanumeric characters in a string

Try:

s = filter(str.isalnum, s)

in Python3:

s = ''.join(filter(str.isalnum, s))

Edit: realized that the OP wants to replace non-chars with '*'. My answer does not fit

How to pass optional arguments to a method in C++?

With commas separating them, just like parameters without default values.

int func( int x = 0, int y = 0 );

func(); // doesn't pass optional parameters, defaults are used, x = 0 and y = 0

func(1, 2); // provides optional parameters, x = 1 and y = 2

Remove characters from a string

You can use replace function.

str.replace(regexp|substr, newSubstr|function)

How to refresh activity after changing language (Locale) inside application

For Android 4.2 (API 17), you need to use android:configChanges="locale|layoutDirection" in your AndroidManifest.xml. See onConfigurationchanged is not called over jellybean(4.2.1)

What does this error mean: "error: expected specifier-qualifier-list before 'type_name'"?

I got it with an import loop:

---FILE B.h
#import "A.h"
@interface B{
  A *a;
}
@end

---FILE A.h
#import "B.h"
@interface A{      
}
@end

How to use EditText onTextChanged event when I press the number?

To change the text; 

multipleLine.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            MainActivity.myArray.set(pickId,String.valueOf(s));
            MainActivity.myAdapt.notifyDataSetChanged();
        }

        @Override
        public void afterTextChanged(Editable s) {

        }

C++ sorting and keeping track of indexes

Using C++ 11 lambdas:

#include <iostream>
#include <vector>
#include <numeric>      // std::iota
#include <algorithm>    // std::sort, std::stable_sort

using namespace std;

template <typename T>
vector<size_t> sort_indexes(const vector<T> &v) {

  // initialize original index locations
  vector<size_t> idx(v.size());
  iota(idx.begin(), idx.end(), 0);

  // sort indexes based on comparing values in v
  // using std::stable_sort instead of std::sort
  // to avoid unnecessary index re-orderings
  // when v contains elements of equal values 
  stable_sort(idx.begin(), idx.end(),
       [&v](size_t i1, size_t i2) {return v[i1] < v[i2];});

  return idx;
}

Now you can use the returned index vector in iterations such as

for (auto i: sort_indexes(v)) {
  cout << v[i] << endl;
}

You can also choose to supply your original index vector, sort function, comparator, or automatically reorder v in the sort_indexes function using an extra vector.

How to make an HTTP POST web request

Simple (one-liner, no error checking, no wait for response) solution I've found so far:

(new WebClient()).UploadStringAsync(new Uri(Address), dataString);?

Use with caution!

CSS ''background-color" attribute not working on checkbox inside <div>

In addition to the currently accepted answer: You can set border and background of a checkbox/radiobutton, but how it is rendered in the end depends on the browser. For example, if you set a red background on a checkbox

  • IE will show a red border instead
  • Opera will show a red background as intended
  • Firefox, Safari and Chrome will do nothing

This German language article compares a few browsers and explains at least the IE behavior. It maybe bit older (still including Netscape), but when you test around you'll notice that not much has changed. Another comparison can be found here.

100% width in React Native Flexbox

width: '100%' and alignSelf: 'stretch' didn't work for me. Dimensions didn't suite my task cause I needed to operate on a deeply nested view. Here's what worked for me, if I rewrite your code. I just added some more Views and used flex properties to achieve the needed layout: 

  {/* a column */}
  <View style={styles.container}>
    {/* some rows here */}
    <Text style={styles.welcome}>
      Welcome to React Natives
    </Text>
    {/* this row should take all available width */}
    <View style={{ flexDirection: 'row' }}>
      {/* flex 1 makes the view take all available width */}
      <View style={{ flex: 1 }}>
        <Text style={styles.line1}>
          line1
        </Text>
      </View>
      {/* I also had a button here, to the right of the text */}
    </View>
    {/* the rest of the rows */}
    <Text style={styles.instructions}>
      Press Cmd+R to reload,{'\n'}
      Cmd+D or shake for dev menu
    </Text>
  </View>

How can I override Bootstrap CSS styles?

In the head section of your html place your custom.css below bootstrap.css.

<link href="bootstrap.min.css" rel="stylesheet">
<link href="custom.css" rel="stylesheet">

Then in custom.css you have to use the exact same selector for the element you want to override. In the case of legend it just stays legend in your custom.css because bootstrap hasn't got any selectors more specific.

legend {
  display: inline;
  width: auto;
  padding: 0;
  margin: 0;
  font-size: medium;
  line-height: normal;
  color: #000000;
  border: 0;
  border-bottom: none;
}

But in case of h1 for example you have to take care of the more specific selectors like .jumbotron h1 because

h1 {
  line-height: 2;
  color: #f00;
}

will not override

.jumbotron h1,
.jumbotron .h1 {
  line-height: 1;
  color: inherit;
}

Here is a helpfull explantion of specificity of css selectors which you need to understand to know exactly which style rules will apply to an element. http://css-tricks.com/specifics-on-css-specificity/

Everything else is just a matter of copy/paste and edit styles.

Bootstrap 3: Keep selected tab on page refresh

This one use HTML5 localStorage to store active tab

$('a[data-toggle="tab"]').on('shown.bs.tab', function(e) {
    localStorage.setItem('activeTab', $(e.target).attr('href'));
});
var activeTab = localStorage.getItem('activeTab');
if (activeTab) {
   $('#navtab-container a[href="' + activeTab + '"]').tab('show');
}

ref: http://www.tutorialrepublic.com/faq/how-to-keep-the-current-tab-active-on-page-reload-in-bootstrap.php https://www.w3schools.com/bootstrap/bootstrap_ref_js_tab.asp

Vagrant stuck connection timeout retrying

One thing to double check is if Hardware Virtualisation is enabled in your machine's BIOS.

My problem is the same string of timeouts but I could only see a black screen in the GUI.

A laptop which I was just setting up kept showing the same problem. After hours of searching I finally found a tip to see if the BIOS had Hardware Virtualisation was enabled.

Here's the content of the post I found:

I see there are still some users who are experiencing this issue. So, I will attempt to summarise a list below of some possible solutions to the SSH timeout problem:

  • Make sure your firewall or antivirus is not blocking the program (which I doubt will happen often)
  • Give your vagrant machine some time for timeouts to happen. If you dont have a very fast PC / Mac, the VM will take while to boot into an SSH ready state, so timeouts will happen.
  • Therefore, first try to let vagrant timeout COMPLETELY before concluding that there is a fault.
  • If vagrant times out completely then increase the timeout limit in the vagrant file to a few min and try again.
  • If that still doesnt work, then try to clean boot your vagrant machine through the VirtualBox interface and enable the GUI of the machine beforehand. If the GUI doesn't show anything happening (ie. just blackscreen, no text) while it is booting, then your vagrant machine has got problems.
  • Destroy the entire machine through the VB interface and reinstall.
  • Delete the ubuntu image files in the Vagrant Images folder in the user folder and redownload and install.
  • Do you even have an intel processor that supports 64bit hardware virtualisation? Google it. If you do, make sure there is no setting in your Bios disabling this feature.
  • Disable hyper-v feature if you are running windows 7 or 8. Google how to disable.
  • Make sure you are running through an SSH enabled client. Use Git bash. Download: http://git-scm.com/downloads
  • Install a 32bit version of ubuntu like trusty32 or precise32. Just change the version in the vagrant file and reinstall vagrant in new directory.
  • Make sure you are using the latest vagrant and virtualbox versions. Last resorts: Format your computer, reinstall windows and buy an intel core isomething processor.

Hope that helps.

Rounded corner for textview in android

Since your top level view already has android:background property set, you can use a <layer-list> (link) to create a new XML drawable that combines both your old background and your new rounded corners background.

Each <item> element in the list is drawn over the next, so the last item in the list is the one that ends up on top.

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <bitmap android:src="@drawable/mydialogbox" />
    </item>
    <item>
        <shape>
            <stroke
                android:width="1dp"
                android:color="@color/common_border_color" />

            <solid android:color="#ffffff" />

            <padding
                    android:left="1dp"
                    android:right="1dp"
                    android:top="1dp" />

            <corners android:radius="5dp" />
        </shape>
    </item>
</layer-list>

AngularJS Dropdown required validation

You need to add a name attribute to your dropdown list, then you need to add a required attribute, and then you can reference the error using myForm.[input name].$error.required:

HTML:

        <form name="myForm" ng-controller="Ctrl" ng-submit="save(myForm)" novalidate>
        <input type="text" name="txtServiceName" ng-model="ServiceName" required>
<span ng-show="myForm.txtServiceName.$error.required">Enter Service Name</span>
<br/>
          <select name="service_id" class="Sitedropdown" style="width: 220px;"          
                  ng-model="ServiceID" 
                  ng-options="service.ServiceID as service.ServiceName for service in services"
                  required> 
            <option value="">Select Service</option> 
          </select> 
          <span ng-show="myForm.service_id.$error.required">Select service</span>

        </form>

    Controller:

        function Ctrl($scope) {
          $scope.services = [
            {ServiceID: 1, ServiceName: 'Service1'},
            {ServiceID: 2, ServiceName: 'Service2'},
            {ServiceID: 3, ServiceName: 'Service3'}
          ];

    $scope.save = function(myForm) {
    console.log('Selected Value: '+ myForm.service_id.$modelValue);
    alert('Data Saved! without validate');
    };
        }

Here's a working plunker.

Handling identity columns in an "Insert Into TABLE Values()" statement?

By default, if you have an identity column, you do not need to specify it in the VALUES section. If your table is:

ID    NAME    ADDRESS

Then you can do:

INSERT INTO MyTbl VALUES ('Joe', '123 State Street, Boston, MA')

This will auto-generate the ID for you, and you don't have to think about it at all. If you SET IDENTITY_INSERT MyTbl ON, you can assign a value to the ID column.

Insert NULL value into INT column

Just use the insert query and put the NULL keyword without quotes. That will work-

INSERT INTO `myDatabase`.`myTable` (`myColumn`) VALUES (NULL);

How do you change text to bold in Android?

If you're drawing it then this will do it:

TextPaint.setFlags(Paint.FAKE_BOLD_TEXT_FLAG);

g++ ld: symbol(s) not found for architecture x86_64

I had a similar warning/error/failure when I was simply trying to make an executable from two different object files (main.o and add.o). I was using the command:

gcc -o exec main.o add.o

But my program is a C++ program. Using the g++ compiler solved my issue:

g++ -o exec main.o add.o

I was always under the impression that gcc could figure these things out on its own. Apparently not. I hope this helps someone else searching for this error.

Counting no of rows returned by a select query

The syntax error is just due to a missing alias for the subquery:

select COUNT(*) from
(
select m.Company_id
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5)  mySubQuery  /* Alias */

How to attach source or JavaDoc in eclipse for any jar file e.g. JavaFX?

I couldn't get the "Attach source..." method to work either, and I tried many different ways. The Javadocs for JavaFX are installed in Program Files\Oracle\JavaFX 2.x SDK\docs. Another way to install the Javadocs is:

  1. Right click on the project, select Properties
  2. Select Libraries on the right side of the tab
  3. At the right top side of the tab, you may see "Default JavaFX Platform" or something similar. Click on the Manage Platforms button. (You can also install this default platform from here if you haven't got this already).
  4. In the Java Platform Manager tab which appears, select "Default JavaFX Platform" on the left side, and then click on the JavaFX tab on the right side of the window.
  5. One of the entry fields is labeled "JavaFX Javadoc". Click the "Browse" button next to this field and browse to the installed docs file mentioned above.

Hope this helps some people who were as puzzled as I was.

Bootstrap select dropdown list placeholder

Yes just "selected disabled" in the option.

<select>
    <option value="" selected disabled>Please select</option>
    <option value="">A</option>
    <option value="">B</option>
    <option value="">C</option>
</select>

Link to fiddle

You can also view the answer at

https://stackoverflow.com/a/5859221/1225125

How to insert tab character when expandtab option is on in Vim

You can disable expandtab option from within Vim as below:

:set expandtab!

or

:set noet

PS: And set it back when you are done with inserting tab, with "set expandtab" or "set et"

PS: If you have tab set equivalent to 4 spaces in .vimrc (softtabstop), you may also like to set it to 8 spaces in order to be able to insert a tab by pressing tab key once instead of twice (set softtabstop=8).

How to find where javaw.exe is installed?

It worked to me:

    String javaHome = System.getProperty("java.home");
    File f = new File(javaHome);
    f = new File(f, "bin");
    f = new File(f, "javaw.exe"); //or f = new File(f, "javaws.exe"); //work too
    System.out.println(f + "    exists: " + f.exists());

Vim clear last search highlighting

You can alternatively add mapping on your .vimrc file as,

nmap <C-N> :nohlsearch

and then you can press

Ctrl+N

to anytime to clear the highlighted text

Fast way to discover the row count of a table in PostgreSQL

For SQL Server (2005 or above) a quick and reliable method is:

SELECT SUM (row_count)
FROM sys.dm_db_partition_stats
WHERE object_id=OBJECT_ID('MyTableName')   
AND (index_id=0 or index_id=1);

Details about sys.dm_db_partition_stats are explained in MSDN

The query adds rows from all parts of a (possibly) partitioned table.

index_id=0 is an unordered table (Heap) and index_id=1 is an ordered table (clustered index)

Even faster (but unreliable) methods are detailed here.

Run text file as commands in Bash

you can make a shell script with those commands, and then chmod +x <scriptname.sh>, and then just run it by 

./scriptname.sh

Its very simple to write a bash script

Mockup sh file:

#!/bin/sh
sudo command1
sudo command2 
.
.
.
sudo commandn

How to iterate through LinkedHashMap with lists as values

In Java 8:

Map<String, List<String>> test1 = new LinkedHashMap<String, List<String>>();
test1.forEach((key,value) -> {
    System.out.println(key + " -> " + value);
});

How do I change an HTML selected option using JavaScript?

I believe that the blog post JavaScript Beginners – Select a dropdown option by value might help you.

<a href="javascript:void(0);" onclick="selectItemByValue(document.getElementById('personlist'),11)">change</a>

function selectItemByValue(elmnt, value){

  for(var i=0; i < elmnt.options.length; i++)
  {
    if(elmnt.options[i].value === value) {
      elmnt.selectedIndex = i;
      break;
    }
  }
}

How to push objects in AngularJS between ngRepeat arrays

Try this one also...

_x000D_
_x000D_ 
<!DOCTYPE html>_x000D_
<html>_x000D_
_x000D_
<body>_x000D_
_x000D_
  <p>Click the button to join two arrays.</p>_x000D_
_x000D_
  <button onclick="myFunction()">Try it</button>_x000D_
_x000D_
  <p id="demo"></p>_x000D_
  <p id="demo1"></p>_x000D_
  <script>_x000D_
    function myFunction() {_x000D_
      var hege = [{_x000D_
        1: "Cecilie",_x000D_
        2: "Lone"_x000D_
      }];_x000D_
      var stale = [{_x000D_
        1: "Emil",_x000D_
        2: "Tobias"_x000D_
      }];_x000D_
      var hege = hege.concat(stale);_x000D_
      document.getElementById("demo1").innerHTML = hege;_x000D_
      document.getElementById("demo").innerHTML = stale;_x000D_
    }_x000D_
  </script>_x000D_
_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

Convert float to double without losing precision

For information this comes under Item 48 - Avoid float and double when exact values are required, of Effective Java 2nd edition by Joshua Bloch. This book is jam packed with good stuff and definitely worth a look.

How to increment a JavaScript variable using a button press event

Had a similar problem. Needed to append as many text inputs as the user wanted, to a form. The functionality of it using jQuery was the answer to the question:

<div id='inputdiv'>
<button id='mybutton'>add an input</button>
</div>

<script>
var thecounter=0; //declare and initialize the counter outside of the function
$('#mybutton').on('click', function(){
thecounter++;
$('#inputdiv').append('<input id="input'+thecounter+'" type="text/>);
});
</script>

Adding the count to each new input id resulted in unique ids which lets you get all the values using the jQuery serialize() function.

How to find common elements from multiple vectors?

A good answer already, but there are a couple of other ways to do this:

unique(c[c%in%a[a%in%b]])

or,

tst <- c(unique(a),unique(b),unique(c))
tst <- tst[duplicated(tst)]
tst[duplicated(tst)]

You can obviously omit the unique calls if you know that there are no repeated values within a, b or c.

get specific row from spark dataframe

This Works for me in PySpark

df.select("column").collect()[0][0]

Parse JSON String into List<string>

Seems like a bad way to do it (creating two correlated lists) but I'm assuming you have your reasons.

I'd parse the JSON string (which has a typo in your example, it's missing a comma between the two objects) into a strongly-typed object and then use a couple of LINQ queries to get the two lists.

void Main()
{
    string json = "{\"People\":[{\"FirstName\":\"Hans\",\"LastName\":\"Olo\"},{\"FirstName\":\"Jimmy\",\"LastName\":\"Crackedcorn\"}]}";

    var result = JsonConvert.DeserializeObject<RootObject>(json);

    var firstNames = result.People.Select (p => p.FirstName).ToList();
    var lastNames = result.People.Select (p => p.LastName).ToList();
}

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

public class RootObject
{
    public List<Person> People { get; set; }
}

How to generate XML file dynamically using PHP?

An easily broken way to do this is :

<?php
// Send the headers
header('Content-type: text/xml');
header('Pragma: public');
header('Cache-control: private');
header('Expires: -1');
echo "<?xml version=\"1.0\" encoding=\"utf-8\"?>";

echo '<xml>';

// echo some dynamically generated content here
/*
<track>
    <path>song_path</path>
    <title>track_number - track_title</title>
</track>
*/

echo '</xml>';

?>

save it as .php

How do I write a Python dictionary to a csv file?

Your code was very close to working.

Try using a regular csv.writer rather than a DictWriter. The latter is mainly used for writing a list of dictionaries.

Here's some code that writes each key/value pair on a separate row:

import csv

somedict = dict(raymond='red', rachel='blue', matthew='green')
with open('mycsvfile.csv','wb') as f:
    w = csv.writer(f)
    w.writerows(somedict.items())

If instead you want all the keys on one row and all the values on the next, that is also easy:

with open('mycsvfile.csv','wb') as f:
    w = csv.writer(f)
    w.writerow(somedict.keys())
    w.writerow(somedict.values())

Pro tip: When developing code like this, set the writer to w = csv.writer(sys.stderr) so you can more easily see what is being generated. When the logic is perfected, switch back to w = csv.writer(f).

Installing OpenCV 2.4.3 in Visual C++ 2010 Express

1. Installing OpenCV 2.4.3

First, get OpenCV 2.4.3 from sourceforge.net. Its a self-extracting so just double click to start the installation. Install it in a directory, say C:\.

OpenCV self-extractor

Wait until all files get extracted. It will create a new directory C:\opencv which contains OpenCV header files, libraries, code samples, etc.

Now you need to add the directory C:\opencv\build\x86\vc10\bin to your system PATH. This directory contains OpenCV DLLs required for running your code.

Open Control Panel → System → Advanced system settings → Advanced Tab → Environment variables...

enter image description here

On the System Variables section, select Path (1), Edit (2), and type C:\opencv\build\x86\vc10\bin; (3), then click Ok.

On some computers, you may need to restart your computer for the system to recognize the environment path variables.

This will completes the OpenCV 2.4.3 installation on your computer.

2. Create a new project and set up Visual C++

Open Visual C++ and select File → New → Project... → Visual C++ → Empty Project. Give a name for your project (e.g: cvtest) and set the project location (e.g: c:\projects).

New project dialog

Click Ok. Visual C++ will create an empty project.

VC++ empty project

Make sure that "Debug" is selected in the solution configuration combobox. Right-click cvtest and select Properties → VC++ Directories.

Project property dialog

Select Include Directories to add a new entry and type C:\opencv\build\include.

Include directories dialog

Click Ok to close the dialog.

Back to the Property dialog, select Library Directories to add a new entry and type C:\opencv\build\x86\vc10\lib.

Library directories dialog

Click Ok to close the dialog.

Back to the property dialog, select Linker → Input → Additional Dependencies to add new entries. On the popup dialog, type the files below:

opencv_calib3d243d.lib
opencv_contrib243d.lib
opencv_core243d.lib
opencv_features2d243d.lib
opencv_flann243d.lib
opencv_gpu243d.lib
opencv_haartraining_engined.lib
opencv_highgui243d.lib
opencv_imgproc243d.lib
opencv_legacy243d.lib
opencv_ml243d.lib
opencv_nonfree243d.lib
opencv_objdetect243d.lib
opencv_photo243d.lib
opencv_stitching243d.lib
opencv_ts243d.lib
opencv_video243d.lib
opencv_videostab243d.lib

Note that the filenames end with "d" (for "debug"). Also note that if you have installed another version of OpenCV (say 2.4.9) these filenames will end with 249d instead of 243d (opencv_core249d.lib..etc).

enter image description here

Click Ok to close the dialog. Click Ok on the project properties dialog to save all settings.

NOTE:

These steps will configure Visual C++ for the "Debug" solution. For "Release" solution (optional), you need to repeat adding the OpenCV directories and in Additional Dependencies section, use:

opencv_core243.lib
opencv_imgproc243.lib
...

instead of:

opencv_core243d.lib
opencv_imgproc243d.lib
...

You've done setting up Visual C++, now is the time to write the real code. Right click your project and select Add → New Item... → Visual C++ → C++ File.

Add new source file

Name your file (e.g: loadimg.cpp) and click Ok. Type the code below in the editor:

#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main()
{
    Mat im = imread("c:/full/path/to/lena.jpg");
    if (im.empty()) 
    {
        cout << "Cannot load image!" << endl;
        return -1;
    }
    imshow("Image", im);
    waitKey(0);
}

The code above will load c:\full\path\to\lena.jpg and display the image. You can use any image you like, just make sure the path to the image is correct.

Type F5 to compile the code, and it will display the image in a nice window.

First OpenCV program

And that is your first OpenCV program!

3. Where to go from here?

Now that your OpenCV environment is ready, what's next?

  1. Go to the samples dir → c:\opencv\samples\cpp.
  2. Read and compile some code.
  3. Write your own code.

How to check if a column exists in a datatable

It is much more accurate to use IndexOf:

If dt.Columns.IndexOf("ColumnName") = -1 Then
    'Column not exist
End If

If the Contains is used it would not differentiate between ColumName and ColumnName2.

Visual studio code CSS indentation and formatting

Beautify (Github) & Prettier (Github) are the best plugin for web development in Visual Studio Code.

How to Customize a Progress Bar In Android

in your xml

<ProgressBar
        android:id="@+id/progressBar1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        style="@style/CustomProgressBar" 
        android:layout_margin="5dip" />

And in res/values/styles.xml:

<resources> 
        <style name="CustomProgressBar" parent="android:Widget.ProgressBar.Horizontal">
          <item name="android:indeterminateOnly">false</item>
          <item name="android:progressDrawable">@drawable/custom_progress_bar_horizontal</item>
          <item name="android:minHeight">10dip</item>
          <item name="android:maxHeight">20dip</item>
        </style>       
    <style name="AppTheme" parent="android:Theme.Light" />
</resources>

And custom_progress_bar_horizontal is a xml stored in drawable folder which defines your custom progress bar. For more detail see this blog.

I hope this will help you.

CSS vertical-align: text-bottom;

Modern solution

Flexbox was created for exactly these kind of problems:

_x000D_
_x000D_ 
#container {_x000D_
    height: 150px;/*Only for the demo.*/_x000D_
    background-color:green;/*Only for the demo.*/_x000D_
    display: flex;_x000D_
    justify-content: center;_x000D_
    align-items: flex-end;_x000D_
}
_x000D_ 
<div id="container">_x000D_
    <span>Text align to center bottom.</span>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Old school solution

If you don't want to mess with table displays, then you can create a <div> inside a relatively positioned parent container, place it to the bottom with absolute positioning, then make it 100% wide, so you can text-align it to the center:

_x000D_
_x000D_ 
#container {_x000D_
    height: 150px;/*Only for the demo.*/_x000D_
    background-color:green;/*Only for the demo.*/_x000D_
    position: relative;_x000D_
}_x000D_
_x000D_
#text {_x000D_
    position: absolute;_x000D_
    bottom: 0;_x000D_
    width: 100%;_x000D_
    text-align: center;_x000D_
}
_x000D_ 
<div id="container">_x000D_
    <span id="text">Text align to center bottom.</span>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Select first occurring element after another element

 
#many .more.selectors h4 + p { ... }

This is called the adjacent sibling selector.

How to correctly dismiss a DialogFragment?

Kotlin Version of Terel answer

(fragmentManager.findFragmentByTag(TAG) as? DialogFragment)?.dismiss()

Regular expression for excluding special characters

Do you really want to blacklist specific characters or rather whitelist the allowed charachters?

I assume that you actually want the latter. This is pretty simple (add any additional symbols to whitelist into the [\-] group):

^(?:\p{L}\p{M}*|[\-])*$

Edit: Optimized the pattern with the input from the comments

How to apply shell command to each line of a command output?

 
for s in `cmd`; do echo $s; done

If cmd has a large output:

cmd | xargs -L1 echo

Python time measure function

Elaborating on @Jonathan Ray I think this does the trick a bit better

import time
import inspect

def timed(f:callable):
    start = time.time()
    ret = f()
    elapsed = 1000*(time.time() - start)
    source_code=inspect.getsource(f).strip('\n') 
    logger.info(source_code+":  "+str(elapsed)+" seconds")
    return ret

It allows to take a regular line of code, say a = np.sin(np.pi) and transform it rather simply into

a = timed(lambda: np.sin(np.pi))

so that the timing is printed onto the logger and you can keep the same assignment of the result to a variable you might need for further work.

I suppose in Python 3.8 one could use the := but I do not have 3.8 yet

PostgreSQL : cast string to date DD/MM/YYYY

The documentation says

The output format of the date/time types can be set to one of the four styles ISO 8601, SQL (Ingres), traditional POSTGRES (Unix date format), or German. The default is the ISO format.

So this particular format can be controlled with postgres date time output, eg:

t=# select now();
              now
-------------------------------
 2017-11-29 09:15:25.348342+00
(1 row)

t=# set datestyle to DMY, SQL;
SET
t=# select now();
              now
-------------------------------
 29/11/2017 09:15:31.28477 UTC
(1 row)

t=# select now()::date;
    now
------------
 29/11/2017
(1 row)

Mind that as @Craig mentioned in his answer, changing datestyle will also (and in first turn) change the way postgres parses date.

setAttribute('display','none') not working

Try this:

setAttribute("hidden", true);

Multiprocessing vs Threading Python

As I learnd in university most of the answers above are right. In PRACTISE on different platforms (always using python) spawning multiple threads ends up like spawning one process. The difference is the multiple cores share the load instead of only 1 core processing everything at 100%. So if you spawn for example 10 threads on a 4 core pc, you will end up getting only the 25% of the cpus power!! And if u spawn 10 processes u will end up with the cpu processing at 100% (if u dont have other limitations). Im not a expert in all the new technologies. Im answering with own real experience background

Transfer git repositories from GitLab to GitHub - can we, how to and pitfalls (if any)?

If you want to migrate the repo including the wiki and all issues and milestones, you can use node-gitlab-2-github and GitLab to GitHub migration

How do you debug MySQL stored procedures?

I'm late to the party, but brought more beer:

http://ocelot.ca/blog/blog/2015/03/02/the-ocelotgui-debugger/ and https://github.com/ocelot-inc/ocelotgui

I tried, and it seems pretty stable, supporting Breakpoints and Variable inspection.

It's not a complete suite (just 4,1 Mb) but helped me a lot!

How it works: It integrates with your mysql client (I'm using Ubuntu 14.04), and after you execute:

$install
$setup yourFunctionName

It installs a new database at your server, that control the debugging process. So:

$debug yourFunctionName('yourParameter')

will give you a chance to step by step walk your code, and "refreshing" your variables you can better view what is going on inside your code.

Important Tip: while debugging, maybe you will change (re-create the procedure). After a re-creation, execute: $exit and $setup before a new $debug

This is an alternative to "insert" and "log" methods. Your code remains free of additional "debug" instructions.

Screenshot:

ocelot breakpoint stepping

setting textColor in TextView in layout/main.xml main layout file not referencing colors.xml file. (It wants a #RRGGBB instead of @color/text_color)

After experimenting on that case: android:textColor="@colors/text_color" is wrong since @color is not filename dependant. You can name your resource file foobar.xml, it doesn't matter but if you have defined some colors in it you can access them using @color/some_color.

Update:

file location: res/values/colors.xml The filename is arbitrary. The element's name will be used as the resource ID. (Source)

Writing List of Strings to Excel CSV File in Python

I know I'm a little late, but something I found that works (and doesn't require using csv) is to write a for loop that writes to your file for every element in your list.

# Define Data
RESULTS = ['apple','cherry','orange','pineapple','strawberry']

# Open File
resultFyle = open("output.csv",'w')

# Write data to file
for r in RESULTS:
    resultFyle.write(r + "\n")
resultFyle.close()

I don't know if this solution is any better than the ones already offered, but it more closely reflects your original logic so I thought I'd share.

Git on Windows: How do you set up a mergetool?

Under Cygwin, the only thing that worked for me is the following:

git config --global merge.tool myp4merge
git config --global mergetool.myp4merge.cmd 'p4merge.exe "$(cygpath -wla $BASE)" "$(cygpath -wla $LOCAL)" "$(cygpath -wla $REMOTE)" "$(cygpath -wla $MERGED)"'
git config --global diff.tool myp4diff
git config --global difftool.myp4diff.cmd 'p4merge.exe "$(cygpath -wla $LOCAL)" "$(cygpath -wla $REMOTE)"'

Also, I like to turn off the prompt message for difftool:

git config --global difftool.prompt false

How can I make a weak protocol reference in 'pure' Swift (without @objc)

Update: It looks like the manual has been updated and the example I was referring to has been removed. See the edit to @flainez's answer above.

Original: Using @objc is the right way to do it even if you're not interoperating with Obj-C. It ensures that your protocol is being applied to a class and not an enum or struct. See "Checking for Protocol Conformance" in the manual.

JQuery select2 set default value from an option in list?

The above solutions did not work for me, but this code from Select2's own website did:

$('select').val('US'); // Select the option with a value of 'US'
$('select').trigger('change'); // Notify any JS components that the value changed

Webpage found here

Hope this helps for anyone who is struggling, like I was.

How to make a node.js application run permanently?

During development, I recommend using nodemon. It will restart your server whenever a file changes. As others have pointed out, Forever is an option but in production, it all depends on the platform you are using. You will typically want to use the operating system's recommended way of keeping services up (e.g. http://www.freedesktop.org/wiki/Software/systemd/).

What are examples of TCP and UDP in real life?

TCP is appropriate when you have to move a decent amount of data (> ~1 kB), and you require all of it to be delivered. Almost all data that moves across the internet does so via TCP - HTTP, SMTP, BitTorrent, SSH, etc, all use TCP.

UDP is appropriate when you have small messages which you can afford to lose, and would like to send them as efficiently as possible. One reason you might be able to afford to lose them is because you can re-send them if they get lost. The main example on the internet is DNS - DNS consists of small queries saying things like "what is the IP number for stackoverflow.com?", and the responses are correspondingly small. Computers make a lot of these queries, so they should be made efficiently, but if they get lost en route, it's easy to time out and re-send them.

What is the correct way to do a CSS Wrapper?

Are there other ways?

Negative margins were also used for horizontal (and vertical!) centering but there are quite a few drawbacks when you resize the window browser: no window slider; the content can't be seen anymore if the size of the window browser is too small.
No surprise as it uses absolute positioning, a beast never completely tamed!

Example: http://bluerobot.com/web/css/center2.html

So that was only FYI as you asked for it, margin: 0 auto; is a better solution.

Comparing two input values in a form validation with AngularJS

You should be able to use ng-pattern/regex for comparing 2 input values

Email:<input type="email" name="email1" ng-model="emailReg">
Repeat Email:<input type="email" name="email2" ng-model="emailReg2" ng-pattern="emailReg">

and validation with:

<span ng-show="registerForm.email2.$error.pattern">Repeat Email should have the same value with email!</span>

Remove composer

 
curl -sS https://getcomposer.org/installer | sudo php
sudo mv composer.phar /usr/local/bin/composer
export PATH="$HOME/.composer/vendor/bin:$PATH"

If you have installed by this way simply

Delete composer.phar from where you've putted it.

In this case path will be /usr/local/bin/composer

Note: There is no need to delete the exported path.

Load and execution sequence of a web page?

If you're asking this because you want to speed up your web site, check out Yahoo's page on Best Practices for Speeding Up Your Web Site. It has a lot of best practices for speeding up your web site.

Get data from JSON file with PHP

 
Try:
$data = file_get_contents ("file.json");
        $json = json_decode($data, true);
        foreach ($json as $key => $value) {
            if (!is_array($value)) {
                echo $key . '=>' . $value . '<br/>';
            } else {
                foreach ($value as $key => $val) {
                    echo $key . '=>' . $val . '<br/>';
                }
            }
        }

accessing a file using [NSBundle mainBundle] pathForResource: ofType:inDirectory:

well i found out the mistake i was committing i was adding a group to the project instead of adding real directory for more instructions

How to know Hive and Hadoop versions from command prompt?

On HDInsight I tried the hive --version, but it did not recognize the option or mention it in the help. 

D:\Users\admin1>%hive_home%/bin/hive --version
Unrecognized option: --version
usage: hive
 -d,--define <key=value>          Variable subsitution to apply to hive
                                  commands. e.g. -d A=B or --define A=B
    --database <databasename>     Specify the database to use
 -e <quoted-query-string>         SQL from command line
 -f <filename>                    SQL from files
 -H,--help                        Print help information
 -h <hostname>                    connecting to Hive Server on remote host
    --hiveconf <property=value>   Use value for given property
    --hivevar <key=value>         Variable subsitution to apply to hive
                                  commands. e.g. --hivevar A=B
 -i <filename>                    Initialization SQL file
 -p <port>                        connecting to Hive Server on port number
 -S,--silent                      Silent mode in interactive shell
 -v,--verbose                     Verbose mode (echo executed SQL to the
                                  console)

However when you login to the head node and start the hive console it prints out some helpful configuration information from which the version can be read:

D:\Users\admin1>%hive_home%/bin/hive 
Logging initialized using configuration in file:/C:/apps/dist/hive-0.13.0.2.1.11.0-2316/conf/hive-log4j.properties
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/apps/dist/hadoop-2.4.0.2.1.11.0-2316/share/hadoop/common/lib/slf4j-log4j12-1.7.5.j
ar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/apps/dist/hbase-0.98.0.2.1.11.0-2316-hadoop2/lib/slf4j-log4j12-1.6.4.jar!/org/slf4
j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
hive> quit;

From this I would say I have Hive version 0.13 deployed, which is consistent with this list of versions https://hive.apache.org/downloads.html

Error when creating a new text file with python?

 
import sys

def write():
    print('Creating new text file') 

    name = raw_input('Enter name of text file: ')+'.txt'  # Name of text file coerced with +.txt

    try:
        file = open(name,'a')   # Trying to create a new file or open one
        file.close()

    except:
        print('Something went wrong! Can\'t tell what?')
        sys.exit(0) # quit Python

write()

this will work promise :)

Format a JavaScript string using placeholders and an object of substitutions?

Currently there is still no native solution in Javascript for this behavior. Tagged templates are something related, but don't solve it.

Here there is a refactor of alex's solution with an object for replacements.

The solution uses arrow functions and a similar syntax for the placeholders as the native Javascript interpolation in template literals ({} instead of %%). Also there is no need to include delimiters (%) in the names of the replacements.

There are two flavors (three with the update): descriptive, reduced, elegant reduced with groups.

Descriptive solution:

_x000D_
_x000D_ 
const stringWithPlaceholders = 'My Name is {name} and my age is {age}.';

const replacements = {
  name: 'Mike',
  age: '26',
};

const string = stringWithPlaceholders.replace(
  /{\w+}/g,
  placeholderWithDelimiters => {
    const placeholderWithoutDelimiters = placeholderWithDelimiters.substring(
      1,
      placeholderWithDelimiters.length - 1,
    );
    const stringReplacement = replacements[placeholderWithoutDelimiters] || placeholderWithDelimiters;
    return stringReplacement;
  },
);

console.log(string);
_x000D_
_x000D_
_x000D_

Reduced solution:

_x000D_
_x000D_ 
const stringWithPlaceholders = 'My Name is {name} and my age is {age}.';

const replacements = {
  name: 'Mike',
  age: '26',
};

const string = stringWithPlaceholders.replace(/{\w+}/g, placeholder =>
  replacements[placeholder.substring(1, placeholder.length - 1)] || placeholder
);

console.log(string);
_x000D_
_x000D_
_x000D_

UPDATE 2020-12-10

Elegant reduced solution with groups, as suggested by @Kade in the comments:

_x000D_
_x000D_ 
const stringWithPlaceholders = 'My Name is {name} and my age is {age}.';

const replacements = {
  name: 'Mike',
  age: '26',
};

const string = stringWithPlaceholders.replace(
  /{(\w+)}/g, 
  (placeholderWithDelimiters, placeholderWithoutDelimiters) =>
    replacements[placeholderWithoutDelimiters] || placeholderWithDelimiters
);

console.log(string);
_x000D_
_x000D_
_x000D_

UPDATE 2021-01-21

Support empty string as a replacement, as suggested by @Jesper in the comments:

_x000D_
_x000D_ 
const stringWithPlaceholders = 'My Name is {name} and my age is {age}.';

const replacements = {
  name: 'Mike',
  age: '',
};

const string = stringWithPlaceholders.replace(
  /{(\w+)}/g, 
  (placeholderWithDelimiters, placeholderWithoutDelimiters) =>
  replacements.hasOwnProperty(placeholderWithoutDelimiters) ? 
    replacements[placeholderWithoutDelimiters] : placeholderWithDelimiters
);

console.log(string);
_x000D_
_x000D_
_x000D_

How to set only time part of a DateTime variable in C#

you can't change the DateTime object, it's immutable. However, you can set it to a new value, for example:

var newDate = oldDate.Date + new TimeSpan(11, 30, 55);

Create a string with n characters

A simple method like below can also be used

public static String padString(String str, int leng,char chr) {
        for (int i = str.length(); i <= leng; i++)
            str += chr;
        return str;
    }

Postgres "psql not recognized as an internal or external command"

Just an update because I was trying it on Windows 10 you do need to set the path to the following: ;C:\Program Files\PostgreSQL\9.5\bin ;C:\Program Files\PostgreSQL\9.5\lib

You can do that either through the CMD by using set PATH [the path] or from my

computer => properties => advanced system settings=> Environment Variables => System Variables

Then search for path.

Important: don't replace the PATHs that are already there just add one beside them as follows ;C:\Program Files\PostgreSQL\9.5\bin ;C:\Program Files\PostgreSQL\9.5\lib

Please note: On windows 10, if you follow this: computer => properties => advanced system settings=> Environment Variables => System Variables> select PATH, you actually get the option to add new row. Click Edit, add the /bin and /lib folder locations and save changes.

Then close your command prompt if it's open and then start it again try psql --version If it gives you an answer then you are good to go if not try echo %PATH% and see if the path you set was added or not and if it's added is it added correctly or not.

Display a float with two decimal places in Python

If you actually want to change the number itself instead of only displaying it differently use format()

Format it to 2 decimal places:

format(value, '.2f')

example:

>>> format(5.00000, '.2f')
'5.00'

Fluid width with equally spaced DIVs

This worked for me with 5 images in diferent sizes.

  1. Create a container div
  2. An Unordered list for the images
  3. On css the unordened must be displayed vertically and without bullets
  4. Justify content of container div

This works because of justify-content:space-between, and it's on a list, displayed horizontally.

On CSS 

 #container {
            display: flex;
            justify-content: space-between;
 }
    #container ul li{ display:inline; list-style-type:none;
}

On html

<div id="container"> 
  <ul>  
        <li><img src="box1.png"><li>
        <li><img src="box2.png"><li>
        <li><img src="box3.png"><li>
        <li><img src="box4.png"><li>
        <li><img src="box5.png"><li>
    </ul>
</div>

Xcode 'CodeSign error: code signing is required'

  • I love Stack Overflow:

  • I realized that some time being too specific is not enough that is because we may have different Xcode version, I have 2 xcode version on the same Mac Pro myself. So here I would like to provide a general instruction that i hope it will work for all Xcode version:

  • My 2 versions are xcode 3.2.6 and 4.0. You need to find (even google for the settings) your xcode BUILD SETTINGS and its CODE SIGNING under CODE SIGNING you have CODE SIGN IDENTITY this provide you a list of IDENTIFIERS (if you do not have IDENTIFIERS go here to get one and registration is required https://developer.apple.com/ios/manage/overview/index.action - follow this instruction of Apple "Get your application on an iOS with the Development Provisioning Assistant") If you have a list of identifiers just select a valid one and run your Xcode again. It will work!

  • 3.2.6 specific: On your scode window - click on Project -> Project settings -> Build (tab) -> there is a scroll down because the list is long MAKING SURE you scroll down to find your CODE SIGNING section

  • 4.0 specific: On your xcode window - click on your project file left most colum -> then next colum click on your target app -> find CODE SIGNING and assign an IDENTIFIER. It should work for you.

Done!

Configuring IntelliJ IDEA for unit testing with JUnit

If you already have test classes you may:

1) Put a cursor on a class declaration and press Alt + Enter. In the dialogue choose JUnit and press Fix. This is a standard way to create test classes in IntelliJ.

2) Alternatively you may add JUnit jars manually (download from site or take from IntelliJ files).

Regular expression to limit number of characters to 10

 
grep '^[0-9]\{1,16\}' | wc -l

Gives the counts with exact match count with limit

Import module from subfolder

Say your project is structured this way:

+---MyPythonProject
|   +---.gitignore
|   +---run.py
|   |   +---subscripts
|   |   |   +---script_one.py
|   |   |   +---script_two.py

Inside run.py, you can import scripts one and two by:

from subscripts import script_one as One
from subscripts import script_two as Two

Now, still inside run.py, you'll be able to call their methods with:

One.method_from_one(param)
Two.method_from_two(other_param)

How to get key names from JSON using jq

echo '{"ab": 1, "cd": 2}' | jq -r 'keys[]' prints all keys one key per line without quotes.

ab
cd

Import text file as single character string

The readr package has a function to do everything for you.

install.packages("readr") # you only need to do this one time on your system
library(readr)
mystring <- read_file("path/to/myfile.txt")

This replaces the version in the package stringr.

How to ignore SSL certificate errors in Apache HttpClient 4.0

Tested with HttpClient 4.5.5 with Fluent API

final SSLContext sslContext = new SSLContextBuilder()
    .loadTrustMaterial(null, (x509CertChain, authType) -> true).build();

CloseableHttpClient httpClient = HttpClients.custom()
    .setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE)
    .setSSLContext(sslContext).build();

String result = Executor.newInstance(httpClient)
    .execute(Request.Get("https://localhost:8080/someapi")
    .connectTimeout(1000).socketTimeout(1000))
    .returnContent().asString();

How does BitLocker affect performance?

With my T7300 2.0GHz and Kingston V100 64gb SSD the results are

Bitlocker off ? on

Sequential read 243 MB/s ? 140 MB/s

Sequential write 74.5 MB/s ? 51 MB/s

Random read 176 MB/s ? 100 MB/s

Random write, and the 4KB speeds are almost identical.

Clearly the processor is the bottleneck in this case. In real life usage however boot time is about the same, cold launch of Opera 11.5 with 79 tabs remained the same 4 seconds all tabs loaded from cache.

A small build in VS2010 took 2 seconds in both situations. Larger build took 2 seconds vs 5 from before. These are ballpark because I'm looking at my watch hand.

I guess it all depends on the combination of processor, ram, and ssd vs hdd. In my case the processor has no hardware AES so compilation is worst case scenario, needing cycles for both assembly and crypto.

A newer system with Sandy Bridge would probably make better use of a Bitlocker enabled SDD in a development environment.

Personally I'm keeping Bitlocker enabled despite the performance hit because I travel often. It took less than an hour to toggle Bitlocker on/off so maybe you could just turn it on when you are traveling then disable it afterwards.

Thinkpad X61, Windows 7 SP1

HTML table sort

Check if you could go with any of the below mentioned JQuery plugins. Simply awesome and provide wide range of options to work through, and less pains to integrate. :)

https://github.com/paulopmx/Flexigrid - Flexgrid
http://datatables.net/index - Data tables.
https://github.com/tonytomov/jqGrid

If not, you need to have a link to those table headers that calls a server-side script to invoke the sort.

convert string date to java.sql.Date

This works for me without throwing an exception:

package com.sandbox;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class Sandbox {

    public static void main(String[] args) throws ParseException {
        SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd");
        Date parsed = format.parse("20110210");
        java.sql.Date sql = new java.sql.Date(parsed.getTime());
    }


}

Convert a matrix to a 1 dimensional array

array(A) or array(t(A)) will give you a 1-d array.

Initialize Array of Objects using NSArray

 
NSMutableArray *persons = [NSMutableArray array];
for (int i = 0; i < myPersonsCount; i++) {
   [persons addObject:[[Person alloc] init]];
}
NSArray *arrayOfPersons = [NSArray arrayWithArray:persons]; // if you want immutable array

also you can reach this without using NSMutableArray:

NSArray *persons = [NSArray array];
for (int i = 0; i < myPersonsCount; i++) {
   persons = [persons arrayByAddingObject:[[Person alloc] init]];
}

One more thing - it's valid for ARC enabled environment, if you going to use it without ARC don't forget to add autoreleased objects into array! 

[persons addObject:[[[Person alloc] init] autorelease];

IntelliJ, can't start simple web application: Unable to ping server at localhost:1099

On top pointing my hostname to 127.0.0.1 in hosts (just run hostname in cmd to get it) as well as doing what David GC mentioned, for me the error cleared and debugging worked when I went into the tomcat configuration and changed the debugging startup script from startup.bat (which was just my monkeying around) back to the catalina.bat start default.

usr/bin/ld: cannot find -l<nameOfTheLibrary>

Apart from the answers already given, it may also be the case that the *.so file exists but is not named properly. Or it may be the case that *.so file exists but it is owned by another user / root.

Issue 1: Improper name

If you are linking the file as -l<nameOfLibrary> then library file name MUST be of the form lib<nameOfLibrary> If you only have <nameOfLibrary>.so file, rename it!

Issue 2: Wrong owner

To verify that this is not the problem - do

ls -l /path/to/.so/file

If the file is owned by root or another user, you need to do

sudo chown yourUserName:yourUserName /path/to/.so/file

Unable to convert MySQL date/time value to System.DateTime

if "allow zero datetime=true" is not working then use the following sollutions:-

Add this to your connection string: "allow zero datetime=no" - that made the type cast work perfectly.

Regular expression for floating point numbers

 
[+/-] [0-9]*.[0-9]+

Try this solution.

how to auto select an input field and the text in it on page load

From http://www.codeave.com/javascript/code.asp?u_log=7004:

_x000D_
_x000D_ 
var input = document.getElementById('myTextInput');_x000D_
input.focus();_x000D_
input.select();
_x000D_ 
<input id="myTextInput" value="Hello world!" />
_x000D_
_x000D_
_x000D_

Where does System.Diagnostics.Debug.Write output appear?

You need to add a TraceListener to see them appear on the Console.

TextWriterTraceListener writer = new TextWriterTraceListener(System.Console.Out);
Debug.Listeners.Add(writer);

They also appear in the Visual Studio Output window when in Debug mode.

Set Windows process (or user) memory limit

No way to do this that I know of, although I'm very curious to read if anyone has a good answer. I have been thinking about adding something like this to one of the apps my company builds, but have found no good way to do it.

The one thing I can think of (although not directly on point) is that I believe you can limit the total memory usage for a COM+ application in Windows. It would require the app to be written to run in COM+, of course, but it's the closest way I know of.

The working set stuff is good (Job Objects also control working sets), but that's not total memory usage, only real memory usage (paged in) at any one time. It may work for what you want, but afaik it doesn't limit total allocated memory.

Explain ExtJS 4 event handling

Firing application wide events

How to make controllers talk to each other ...

In addition to the very great answer above I want to mention application wide events which can be very useful in an MVC setup to enable communication between controllers. (extjs4.1)

Lets say we have a controller Station (Sencha MVC examples) with a select box:

Ext.define('Pandora.controller.Station', {
    extend: 'Ext.app.Controller',
    ...

    init: function() {
        this.control({
            'stationslist': {
                selectionchange: this.onStationSelect
            },
            ...
        });
    },

    ...

    onStationSelect: function(selModel, selection) {
        this.application.fireEvent('stationstart', selection[0]);
    },    
   ...
});

When the select box triggers a change event, the function onStationSelect is fired.

Within that function we see:

this.application.fireEvent('stationstart', selection[0]);

This creates and fires an application wide event that we can listen to from any other controller.

Thus in another controller we can now know when the station select box has been changed. This is done through listening to this.application.on as follows:

Ext.define('Pandora.controller.Song', {
    extend: 'Ext.app.Controller', 
    ...
    init: function() {
        this.control({
            'recentlyplayedscroller': {
                selectionchange: this.onSongSelect
            }
        });

        // Listen for an application wide event
        this.application.on({
            stationstart: this.onStationStart, 
                scope: this
        });
    },
    ....
    onStationStart: function(station) {
        console.info('I called to inform you that the Station controller select box just has been changed');
        console.info('Now what do you want to do next?');
    },
}

If the selectbox has been changed we now fire the function onStationStart in the controller Song also ...

From the Sencha docs:

Application events are extremely useful for events that have many controllers. Instead of listening for the same view event in each of these controllers, only one controller listens for the view event and fires an application-wide event that the others can listen for. This also allows controllers to communicate with one another without knowing about or depending on each other’s existence.

In my case: Clicking on a tree node to update data in a grid panel.

Update 2016 thanks to @gm2008 from the comments below:

In terms of firing application-wide custom events, there is a new method now after ExtJS V5.1 is published, which is using Ext.GlobalEvents.

When you fire events, you can call: Ext.GlobalEvents.fireEvent('custom_event');

When you register a handler of the event, you call: Ext.GlobalEvents.on('custom_event', function(arguments){/* handler codes*/}, scope);

This method is not limited to controllers. Any component can handle a custom event through putting the component object as the input parameter scope.

Found in Sencha Docs: MVC Part 2

rm: cannot remove: Permission denied

The code says everything:

max@serv$ chmod 777 .

Okay, it doesn't say everything.

In UNIX and Linux, the ability to remove a file is not determined by the access bits of that file. It is determined by the access bits of the directory which contains the file.

Think of it this way -- deleting a file doesn't modify that file. You aren't writing to the file, so why should "w" on the file matter? Deleting a file requires editing the directory that points to the file, so you need "w" on the that directory.

What is the correct Performance Counter to get CPU and Memory Usage of a Process?

Pelo Hyper-V:

private PerformanceCounter theMemCounter = new PerformanceCounter(
    "Hyper-v Dynamic Memory VM",
    "Physical Memory",
    Process.GetCurrentProcess().ProcessName);

How to stop PHP code execution?

Apart from the obvious die() and exit(), this also works:

<?php
echo "start";
__halt_compiler();
echo "you should not see this";
?>

Excel VBA, How to select rows based on data in a column?

The easiest way to do it is to use the End method, which is gives you the cell that you reach by pressing the end key and then a direction when you're on a cell (in this case B6). This won't give you what you expect if B6 or B7 is empty, though.

Dim start_cell As Range
Set start_cell = Range("[Workbook1.xlsx]Sheet1!B6")
Range(start_cell, start_cell.End(xlDown)).Copy Range("[Workbook2.xlsx]Sheet1!A2")

If you can't use End, then you would have to use a loop.

Dim start_cell As Range, end_cell As Range

Set start_cell = Range("[Workbook1.xlsx]Sheet1!B6")
Set end_cell = start_cell

Do Until IsEmpty(end_cell.Offset(1, 0))
    Set end_cell = end_cell.Offset(1, 0)
Loop

Range(start_cell, end_cell).Copy Range("[Workbook2.xlsx]Sheet1!A2")

List supported SSL/TLS versions for a specific OpenSSL build

This worked for me:

openssl s_client -help 2>&1  > /dev/null | egrep "\-(ssl|tls)[^a-z]"

Please let me know if this is wrong.

How can I select an element by name with jQuery?

You can use the function:

get.elementbyId();

Using "label for" on radio buttons

(Firstly read the other answers which has explained the for in the <label></label> tags. Well, both the tops answers are correct, but for my challenge, it was when you have several radio boxes, you should select for them a common name like name="r1" but with different ids id="r1_1" ... id="r1_2"

So this way the answer is more clear and removes the conflicts between name and ids as well.

You need different ids for different options of the radio box.

_x000D_
_x000D_ 
<input type="radio" name="r1" id="r1_1" />_x000D_
_x000D_
       <label for="r1_1">button text one</label>_x000D_
       <br/>_x000D_
       <input type="radio" name="r1" id="r1_2" />_x000D_
_x000D_
       <label for="r1_2">button text two</label>_x000D_
       <br/>_x000D_
       <input type="radio" name="r1" id="r1_3" />_x000D_
_x000D_
       <label for="r1_3">button text three</label>
_x000D_
_x000D_
_x000D_

How to add two strings as if they were numbers?

MDN docs for parseInt
MDN docs for parseFloat

In parseInt radix is specified as ten so that we are in base 10. In nonstrict javascript a number prepended with 0 is treated as octal. This would obviously cause problems!

parseInt(num1, 10) + parseInt(num2, 10) //base10
parseFloat(num1) + parseFloat(num2)

Also see ChaosPandion's answer for a useful shortcut using a unary operator. I have set up a fiddle to show the different behaviors.

http://jsfiddle.net/EtX6G/

var ten = '10';
var zero_ten = '010';
var one = '1';
var body = document.getElementsByTagName('body')[0];

Append(parseInt(ten) + parseInt(one));
Append(parseInt(zero_ten) + parseInt(one));
Append(+ten + +one);
Append(+zero_ten + +one);

function Append(text) {
    body.appendChild(document.createTextNode(text));
    body.appendChild(document.createElement('br'));
}

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

I had the same issue but when i deleted the cached items from Temp folder the build failed.

In order to make the build work again I had to close the project and reopen it.

How to use '-prune' option of 'find' in sh?

If you read all the good answers here my understanding now is that the following all return the same results:

find . -path ./dir1\*  -prune -o -print

find . -path ./dir1  -prune -o -print

find . -path ./dir1\*  -o -print
#look no prune at all!

But the last one will take a lot longer as it still searches out everything in dir1. I guess the real question is how to -or out unwanted results without actually searching them.

So I guess prune means don't decent past matches but mark it as done...

http://www.gnu.org/software/findutils/manual/html_mono/find.html "This however is not due to the effect of the ‘-prune’ action (which only prevents further descent, it doesn't make sure we ignore that item). Instead, this effect is due to the use of ‘-o’. Since the left hand side of the “or” condition has succeeded for ./src/emacs, it is not necessary to evaluate the right-hand-side (‘-print’) at all for this particular file."

CSS: center element within a <div> element

Actually this is very straightforward with CSS3 flex boxes.

_x000D_
_x000D_ 
.flex-container{
  display: -webkit-box;  /* OLD - iOS 6-, Safari 3.1-6, BB7 */
  display: -ms-flexbox;  /* TWEENER - IE 10 */
  display: -webkit-flex; /* NEW - Safari 6.1+. iOS 7.1+, BB10 */
  display: flex;         /* NEW, Spec - Firefox, Chrome, Opera */
  
  justify-content: center;
  align-items: center;
  
  width: 400px;
  height: 200px;
  background-color: #3498db;
}

.inner-element{
  width: 100px;
  height: 100px;
  background-color: #f1c40f;
}
_x000D_ 
<div class="flex-container">
  <div class="inner-element"></div>
</div>
_x000D_
_x000D_
_x000D_

UPDATE:

It seems that I didn't read the OP edit at the time I wrote this answer. The above code will center all inner elements (without overlapping between them), but the OP wants just an specific element to be centered, not the other inner elements. So @Warface answer second method is more appropiate, but it still requires vertical centering:

_x000D_
_x000D_ 
.flex-container{
  position: relative;
  
  /* Other styling stuff */
  width: 400px;
  height: 200px;
  background-color: #3498db;
}

.inner-element{
  position: absolute;
  left: 50%;
  top: 50%;
  
  transform: translate(-50%,-50%);
  /* or 3d alternative if you will add animations (smoother transitions) */
  transform: translate3d(-50%,-50%,0);

  /* Other styling stuff */
  width: 100px;
  height: 100px;
  background-color: #f1c40f;
}
_x000D_ 
<div class="flex-container">
  <p>Other inner elements like this follows the normal flow.</p>
  <div class="inner-element"></div>
</div>
_x000D_
_x000D_
_x000D_

java.net.UnknownHostException: Invalid hostname for server: local

Trying to connect to your local computer.try with the hostname "localhost" instead or perhaps ::/ - the last one is ipv6

Bitwise operation and usage

Sets

Sets can be combined using mathematical operations.

  • The union operator | combines two sets to form a new one containing items in either.
  • The intersection operator & gets items only in both.
  • The difference operator - gets items in the first set but not in the second.
  • The symmetric difference operator ^ gets items in either set, but not both.

Try It Yourself:

first = {1, 2, 3, 4, 5, 6}
second = {4, 5, 6, 7, 8, 9}

print(first | second)

print(first & second)

print(first - second)

print(second - first)

print(first ^ second)

Result:

{1, 2, 3, 4, 5, 6, 7, 8, 9}

{4, 5, 6}

{1, 2, 3}

{8, 9, 7}

{1, 2, 3, 7, 8, 9}

Laravel Migration Error: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

This issue is caused in Laravel 5.4 by the database version.

According to the docs (in the Index Lengths & MySQL / MariaDB section):

Laravel uses the utf8mb4 character set by default, which includes support for storing "emojis" in the database. If you are running a version of MySQL older than the 5.7.7 release or MariaDB older than the 10.2.2 release, you may need to manually configure the default string length generated by migrations in order for MySQL to create indexes for them. You may configure this by calling the Schema::defaultStringLength method within your AppServiceProvider.

In other words, in <ROOT>/app/Providers/AppServiceProvider.php:

// Import Schema
use Illuminate\Support\Facades\Schema;
// ...

class AppServiceProvider extends ServiceProvider
{

public function boot()
{
    // Add the following line
    Schema::defaultStringLength(191);
}

// ...

}

But as the comment on the other answer says:

Be careful about this solution. If you index email fields for example, stored emails can only have a max length of 191 chars. This is less than the official RFC states.

So the documentation also proposes another solution:

Alternatively, you may enable the innodb_large_prefix option for your database. Refer to your database's documentation for instructions on how to properly enable this option.

An Iframe I need to refresh every 30 seconds (but not the whole page)

add "id='myiframe'" to the iframe, then use this script :

<script>

function f1()
{
 var x=document.getElementById("myiframe");
   x.src=x.src+Math.floor(random()%100000);
}

setInterval(f1,30*1000);

</script>

Loading cross-domain endpoint with AJAX

To get the data form external site by passing using a local proxy as suggested by jherax you can create a php page that fetches the content for you from respective external url and than send a get request to that php page.

var req = new XMLHttpRequest();
req.open('GET', 'http://localhost/get_url_content.php',false);
if(req.status == 200) {
   alert(req.responseText);
}

as a php proxy you can use https://github.com/cowboy/php-simple-proxy

Where can I find the assembly System.Web.Extensions dll?

I had this issue when converting an older project to use a new version of Visual Studio. Upon conversion, the project target framework was set to 2.0

I was able to solve this issue by changing the target framework to be 3.5.

How to return a class object by reference in C++?

You can only use

     Object& return_Object();

if the object returned has a greater scope than the function. For example, you can use it if you have a class where it is encapsulated. If you create an object in your function, use pointers. If you want to modify an existing object, pass it as an argument.

  class  MyClass{
      private:
        Object myObj;

      public:
         Object& return_Object() {
            return myObj;
         }

         Object* return_created_Object() {
            return new Object();
         }

         bool modify_Object( Object& obj) {
            //  obj = myObj; return true; both possible
            return obj.modifySomething() == true;
         }
   };

How can I tell where mongoDB is storing data? (its not in the default /data/db!)

If you could somehow locate mongod.log and the do a grep over it

grep dbpath mongod.log

The value for dbpath is the data location for mongodb!! All the best :)

Get height of div with no height set in css

Also make sure the div is currently appended to the DOM and visible.

Excel formula is only showing the formula rather than the value within the cell in Office 2010

Add an = at the beginning. That makes it a function rather than an entry.

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

If you use Tomcat, you can map resources to the default servlet:

<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>/static/*</url-pattern>
</servlet-mapping>

and access your resources with url http://{context path}/static/res/...

Also works with Jetty, not sure about other servlet containers.

Getting current directory in VBScript

 
'-----Implementation of VB6 App object in VBScript-----
Class clsApplication
    Property Get Path()
          Dim sTmp
          If IsObject(Server) Then
               'Classic ASP
               Path = Server.MapPath("../")
          ElseIf IsObject(WScript) Then 
               'Windows Scripting Host
               Path = Left(WScript.ScriptFullName, InStr(WScript.ScriptFullName, WScript.ScriptName) - 2)
          ElseIf IsObject(window) Then
               'Internet Explorer HTML Application (HTA)
               sTmp = Replace( Replace(Unescape(window.location), "file:///", "") ,"/", "\")
               Path = Left(sTmp, InstrRev( sTmp , "\") - 1)
          End If
    End Property
End Class
Dim App : Set App = New clsApplication 'use as App.Path

Ruby: How to turn a hash into HTTP parameters?

No need to load up the bloated ActiveSupport or roll your own, you can use Rack::Utils.build_query and Rack::Utils.build_nested_query. Here's a blog post that gives a good example:

require 'rack'

Rack::Utils.build_query(
  authorization_token: "foo",
  access_level: "moderator",
  previous: "index"
)

# => "authorization_token=foo&access_level=moderator&previous=index"

It even handles arrays:

Rack::Utils.build_query( {:a => "a", :b => ["c", "d", "e"]} )
# => "a=a&b=c&b=d&b=e"
Rack::Utils.parse_query _
# => {"a"=>"a", "b"=>["c", "d", "e"]}

Or the more difficult nested stuff:

Rack::Utils.build_nested_query( {:a => "a", :b => [{:c => "c", :d => "d"}, {:e => "e", :f => "f"}] } )
# => "a=a&b[][c]=c&b[][d]=d&b[][e]=e&b[][f]=f"
Rack::Utils.parse_nested_query _
# => {"a"=>"a", "b"=>[{"c"=>"c", "d"=>"d", "e"=>"e", "f"=>"f"}]}

Compression/Decompression string with C#

For those who still getting The magic number in GZip header is not correct. Make sure you are passing in a GZip stream. ERROR and if your string was zipped using php you'll need to do something like:

       public static string decodeDecompress(string originalReceivedSrc) {
        byte[] bytes = Convert.FromBase64String(originalReceivedSrc);

        using (var mem = new MemoryStream()) {
            //the trick is here
            mem.Write(new byte[] { 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00 }, 0, 8);
            mem.Write(bytes, 0, bytes.Length);

            mem.Position = 0;

            using (var gzip = new GZipStream(mem, CompressionMode.Decompress))
            using (var reader = new StreamReader(gzip)) {
                return reader.ReadToEnd();
                }
            }
        }

Session variables not working php

I had similar issue and with the cookie domain:

    ini_set('session.cookie_domain', '.domain.com');

the domain was setup wrong so all sessions were ignored because the user cookie was never set right hope this will help someone.

Using subprocess to run Python script on Windows

You are using a pathname separator which is platform dependent. Windows uses "\" and Unix uses "/".

Iterate through a HashMap

Depends. If you know you're going to need both the key and the value of every entry, then go through the entrySet. If you just need the values, then there's the values() method. And if you just need the keys, then use keyset().

A bad practice would be to iterate through all of the keys, and then within the loop, always do map.get(key) to get the value. If you're doing that, then the first option I wrote is for you.

How can I check if the current date/time is past a set date/time?

 
date_default_timezone_set('Asia/Kolkata');

$curDateTime = date("Y-m-d H:i:s");
$myDate = date("Y-m-d H:i:s", strtotime("2018-06-26 16:15:33"));
if($myDate < $curDateTime){
    echo "active";exit;
}else{
    echo "inactive";exit;
}

jQuery Validate - Enable validation for hidden fields

So I'm going to go a bit deeper in to why this doesn't work because I'm the kind of person that can't sleep at night without knowing haha. I'm using jQuery validate 1.10 and Microsoft jQuery Unobtrusive Validation 2.0.20710.0 which was published on 1/29/2013.

I started by searching for the setDefaults method in jQuery Validate and found it on line 261 of the unminified file. All this function really does is merge your json settings in to the existing $.validator.defaults which are initialized with the ignore property being set to ":hidden" along with the other defaults defined in jQuery Validate. So at this point we've overridden ignore. Now let's see where this defaults property is being referenced at.

When I traced through the code to see where $.validator.defaults is being referenced. I noticed that is was only being used by the constructor for a form validator, line 170 in jQuery validate unminified file.

// constructor for validator
$.validator = function( options, form ) {
    this.settings = $.extend( true, {}, $.validator.defaults, options );
    this.currentForm = form;
    this.init();
};

At this point a validator will merge any default settings that were set and attach it to the form validator. When you look at the code that is doing the validating, highlighting, unhighlighting, etc they all use the validator.settings object to pull the ignore property. So we need to make sure if we are to set the ignore with the setDefaults method then it has to occur before the $("form").validate() is called.

If you're using Asp.net MVC and the unobtrusive plugin, then you'll realize after looking at the javascript that validate is called in document.ready. I've also called my setDefaults in the document.ready block which is going to execute after the scripts, jquery validate and unobtrusive because I've defined those scripts in the html before the one that has the call in it. So my call obviously had no impact on the default functionality of skipping hidden elements during validation. There is a couple of options here.

Option 1 - You could as Juan Mellado pointed out have the call outside of the document.ready which would execute as soon as the script has been loaded. I'm not sure about the timing of this since browsers are now capable of doing parallel script loading. If I'm just being over cautious then please correct me. Also, there's probably ways around this but for my needs I did not go down this path.

Option 2a - The safe bet in my eyes is to just replace the $.validator.setDefaults({ ignore: '' }); inside of the document.ready event with $("form").data("validator").settings.ignore = "";. This will modify the ignore property that is actually used by jQuery validate when doing each validation on your elements for the given form.

Options 2b - After looking in to the code a bit more you could also use $("form").validate().settings.ignore = ""; as a way of setting the ignore property. The reason is that when looking at the validate function it checks to see if a validator object has already been stored for the form element via the $.data() function. If it finds a validator object stored with the form element then it just returns the validator object instead of creating another one.

Date formatting in WPF datagrid

This is a very old question, but I found a new solution, so I wrote about it.

First of all, is this way of solution possible while using AutoGenerateColumns?

Yes, that can be done with AttachedProperty as follows.

<DataGrid AutoGenerateColumns="True" 
   local:DataGridOperation.DateTimeFormatAutoGenerate="yy-MM-dd"
   ItemsSource="{Binding}" />

AttachedProperty

There are two AttachedProperty defined that allow you to specify two formats. DateTimeFormatAutoGenerate for DateTime and TimeSpanFormatAutoGenerate for TimeSpan.

class DataGridOperation
{
    public static string GetDateTimeFormatAutoGenerate(DependencyObject obj) => (string)obj.GetValue(DateTimeFormatAutoGenerateProperty);
    public static void SetDateTimeFormatAutoGenerate(DependencyObject obj, string value) => obj.SetValue(DateTimeFormatAutoGenerateProperty, value);
    public static readonly DependencyProperty DateTimeFormatAutoGenerateProperty =
        DependencyProperty.RegisterAttached("DateTimeFormatAutoGenerate", typeof(string), typeof(DataGridOperation),
            new PropertyMetadata(null, (d, e) => AddEventHandlerOnGenerating<DateTime>(d, e)));

    public static string GetTimeSpanFormatAutoGenerate(DependencyObject obj) => (string)obj.GetValue(TimeSpanFormatAutoGenerateProperty);
    public static void SetTimeSpanFormatAutoGenerate(DependencyObject obj, string value) => obj.SetValue(TimeSpanFormatAutoGenerateProperty, value);
    public static readonly DependencyProperty TimeSpanFormatAutoGenerateProperty =
        DependencyProperty.RegisterAttached("TimeSpanFormatAutoGenerate", typeof(string), typeof(DataGridOperation),
            new PropertyMetadata(null, (d, e) => AddEventHandlerOnGenerating<TimeSpan>(d, e)));

    private static void AddEventHandlerOnGenerating<T>(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (!(d is DataGrid dGrid))
            return;

        if ((e.NewValue is string format))
            dGrid.AutoGeneratingColumn += (o, e) => AddFormat_OnGenerating<T>(e, format);
    }

    private static void AddFormat_OnGenerating<T>(DataGridAutoGeneratingColumnEventArgs e, string format)
    {
        if (e.PropertyType == typeof(T))
            (e.Column as DataGridTextColumn).Binding.StringFormat = format;
    }
}

How to use

View

<Window
   x:Class="DataGridAutogenerateCustom.MainWindow"
   xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
   xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
   xmlns:local="clr-namespace:DataGridAutogenerateCustom"
   Width="400" Height="250">
   <Window.DataContext>
      <local:MainWindowViewModel />
   </Window.DataContext>
   <StackPanel>
      <TextBlock Text="DEFAULT FORMAT" />
      <DataGrid ItemsSource="{Binding Dates}" />

      <TextBlock Margin="0,30,0,0" Text="CUSTOM FORMAT" />
      <DataGrid
         local:DataGridOperation.DateTimeFormatAutoGenerate="yy-MM-dd"
         local:DataGridOperation.TimeSpanFormatAutoGenerate="dd\-hh\-mm\-ss"
         ItemsSource="{Binding Dates}" />
   </StackPanel>
</Window>

ViewModel

public class MainWindowViewModel
{
    public DatePairs[] Dates { get; } = new DatePairs[]
    {
        new (){StartDate= new (2011,1,1), EndDate= new (2011,2,1) },
        new (){StartDate= new (2020,1,1), EndDate= new (2021,1,1) },
    };
}

public class DatePairs
{
    public DateTime StartDate { get; set; }
    public DateTime EndDate { get; set; }
    public TimeSpan Span => EndDate - StartDate;
}

demo_wpf_datagrid

How to import or copy images to the "res" folder in Android Studio?
  1. go to your image in windows and copy it
  2. go to the res folder and select one of the drawable folders and paste the image in there
  3. click on imageview then go to properties and scroll down until you see src
  4. insert this into src @drawable/imagename

Why is division in Ruby returning an integer instead of decimal value?

Fixnum#to_r is not mentioned here, it was introduced since ruby 1.9. It converts Fixnum into rational form. Below are examples of its uses. This also can give exact division as long as all the numbers used are Fixnum. 

 a = 1.to_r  #=> (1/1) 
 a = 10.to_r #=> (10/1) 
 a = a / 3   #=> (10/3) 
 a = a * 3   #=> (10/1) 
 a.to_f      #=> 10.0

Example where a float operated on a rational number coverts the result to float.

a = 5.to_r   #=> (5/1) 
a = a * 5.0  #=> 25.0

mysql_config not found when installing mysqldb python interface

The commands (mysql too) mPATH might be missing.

export PATH=$PATH:/usr/local/mysql/bin/

Iterating over Numpy matrix rows to apply a function each?

While you should certainly provide more information, if you are trying to go through each row, you can just iterate with a for loop:

import numpy
m = numpy.ones((3,5),dtype='int')
for row in m:
  print str(row)

Cannot add or update a child row: a foreign key constraint fails

If you use mysql index or relation between tables, firstly you delete the colums(for example:city_id) and create new colums with same name(for example:city_id).Then try again...

Attempted to read or write protected memory. This is often an indication that other memory is corrupt

This issue is almost invariably a simple one. The code is bad. It's rarely the tools, just from a statistical analysis. Untold millions of people are using Visual Studio every day and maybe a few are using your code - which bit of code is getting the better testing? I guarantee that, if this were a problem with VS, we would probably already have found it.

What the statement means is that, when you try to access memory that isn't yours, it's usually because you're doing it with a corrupted pointer, that came from somewhere else. That's why it's stating the indication.

With memory corruption, the catching of the error is rarely near the root cause of the error. And the effects are exactly what you describe, seemingly random. You'll just have to look at the usual culprits, things like:

  • uninitialised pointers or other values.
  • writing more to a buffer than its size.
  • resources shared by threads that aren't protected by mutexes.

Working backwards from a problem like this to find the root cause is incredibly difficult given that so much could have happened between the creation of the problem and the detection of the problem.

I mostly find it's easier to have a look at what is corrupt (say, a specific pointer) and then do manual static analysis of the code to see what could have corrupted it, checking for the usual culprits as shown above. However, even this won't catch long chains of problems.

I'm not familiar enough with VS to know but you may also want to look into the possibility of using a memory tracking tool (like valgrind for Linux) to see if it can spot any obvious issues.

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

A simple solution could be:

interface bar {
    length: number;
}

let bars: bar[];
bars = [];