Programs & Examples On #Alias data type

How to display Woocommerce product price by ID number on a custom page?

Other answers work, but

To get the full/default price:

$product->get_price_html();

How to call codeigniter controller function from view

class MY_Controller extends CI_Controller {

    public $CI = NULL;

    public function __construct() {
        parent::__construct();
        $this->CI = & get_instance();
    }

    public function yourMethod() {

    }

}

// in view just call
$this->CI->yourMethod();

Programmatically change the src of an img tag

Maybe because you have a tag like a parent of the tag. That why you have to click two time the images.

For me the solution is this: http://www.w3schools.com/js/tryit.asp?filename=tryjs_intro_lightbulb

Underscore prefix for property and method names in JavaScript

That's only a convention. The Javascript language does not give any special meaning to identifiers starting with underscore characters.

That said, it's quite a useful convention for a language that doesn't support encapsulation out of the box. Although there is no way to prevent someone from abusing your classes' implementations, at least it does clarify your intent, and documents such behavior as being wrong in the first place.

How to display hexadecimal numbers in C?

i use it like this:

printf("my number is 0x%02X\n",number);
// output: my number is 0x4A

Just change number "2" to any number of chars You want to print ;)

In Tensorflow, get the names of all the Tensors in a graph

Since the OP asked for the list of the tensors instead of the list of operations/nodes, the code should be slightly different:

graph = tf.get_default_graph()    
tensors_per_node = [node.values() for node in graph.get_operations()]
tensor_names = [tensor.name for tensors in tensors_per_node for tensor in tensors]

Find character position and update file name

I know this thread is a bit old but, I was looking for something similar and could not find it. Here's what I came up with. I create a string object using the .Net String class to expose all the methods normally found if using C#

[System.String]$myString
 $myString = "237801_201011221155.xml"
 $startPos = $myString.LastIndexOf("_") + 1 # Do not include the "_" character
 $subString = $myString.Substring($startPos,$myString.Length - $startPos)

Result: 201011221155.xml

Browserslist: caniuse-lite is outdated. Please run next command `npm update caniuse-lite browserslist`

In my case this works fine...

sudo npm i -g browserslist caniuse-lite

How to get only the last part of a path in Python?

During my current projects, I'm often passing rear parts of a path to a function and therefore use the Path module. To get the n-th part in reverse order, I'm using:

from typing import Union
from pathlib import Path

def get_single_subpath_part(base_dir: Union[Path, str], n:int) -> str:
    if n ==0:
        return Path(base_dir).name
    for _ in range(n):
        base_dir = Path(base_dir).parent
    return getattr(base_dir, "name")

path= "/folderA/folderB/folderC/folderD/"

# for getting the last part:
print(get_single_subpath_part(path, 0))
# yields "folderD"

# for the second last
print(get_single_subpath_part(path, 1))
#yields "folderC"

Furthermore, to pass the n-th part in reverse order of a path containing the remaining path, I use:

from typing import Union
from pathlib import Path

def get_n_last_subparts_path(base_dir: Union[Path, str], n:int) -> Path:
    return Path(*Path(base_dir).parts[-n-1:])

path= "/folderA/folderB/folderC/folderD/"

# for getting the last part:
print(get_n_last_subparts_path(path, 0))
# yields a `Path` object of "folderD"

# for second last and last part together 
print(get_n_last_subparts_path(path, 1))
# yields a `Path` object of "folderc/folderD"

Note that this function returns a Pathobject which can easily be converted to a string (e.g. str(path))

Searching a list of objects in Python

Consider using a dictionary:

myDict = {}

for i in range(20):
    myDict[i] = i * i

print(5 in myDict)

Is there a way to get a collection of all the Models in your Rails app?

I looked for ways to do this and ended up choosing this way:

in the controller:
    @data_tables = ActiveRecord::Base.connection.tables

in the view:
  <% @data_tables.each do |dt|  %>
  <br>
  <%= dt %>
  <% end %>
  <br>

source: http://portfo.li/rails/348561-how-can-one-list-all-database-tables-from-one-project

Visual studio - getting error "Metadata file 'XYZ' could not be found" after edit continue

I had same issue too.

In my case, I recently add an internal class to somewhere in project. One of the dependencies in solution has same class name and both of them are added correctly to references.

I changed my last activity and rebuild, it works.

Be sure that your compiler messages are valid. In my case I catch reference error from there, not listed as an error in Error List.

Replacing Pandas or Numpy Nan with a None to use with MysqlDB

Just an addition to @Andy Hayden's answer:

Since DataFrame.mask is the opposite twin of DataFrame.where, they have the exactly same signature but with opposite meaning:

  • DataFrame.where is useful for Replacing values where the condition is False.
  • DataFrame.mask is used for Replacing values where the condition is True.

So in this question, using df.mask(df.isna(), other=None, inplace=True) might be more intuitive.

How to retrieve the dimensions of a view?

You are trying to get width and height of an elements, that weren't drawn yet.

If you use debug and stop at some point, you'll see, that your device screen is still empty, that's because your elements weren't drawn yet, so you can't get width and height of something, that doesn't yet exist.

And, I might be wrong, but setWidth() is not always respected, Layout lays out it's children and decides how to measure them (calling child.measure()), so If you set setWidth(), you are not guaranteed to get this width after element will be drawn.

What you need, is to use getMeasuredWidth() (the most recent measure of your View) somewhere after the view was actually drawn.

Look into Activity lifecycle for finding the best moment.

http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle

I believe a good practice is to use OnGlobalLayoutListener like this:

yourView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            if (!mMeasured) {
                // Here your view is already layed out and measured for the first time
                mMeasured = true; // Some optional flag to mark, that we already got the sizes
            }
        }
    });

You can place this code directly in onCreate(), and it will be invoked when views will be laid out.

Android: how to handle button click

My sample, Tested in Android studio 2.1

Define button in xml layout

<Button
    android:id="@+id/btn1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

Java pulsation detect

Button clickButton = (Button) findViewById(R.id.btn1);
if (clickButton != null) {
    clickButton.setOnClickListener( new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            /***Do what you want with the click here***/
        }
    });
}

Nginx 403 forbidden for all files

If you are using PHP, make sure the index NGINX directive in the server block contains a index.php:

index index.php index.html;

For more info checkout the index directive in the official documentation.

write newline into a file

the other answers should work. however I wanna mention

from java doc:

FileWriter is meant for writing streams of characters. For writing streams of raw bytes, consider using a FileOutputStream.

reading your method codes, you are about to write String to the file, what you were doing is convert String to raw bytes, then write so I think using FileWriter is not a bad idea.

And for the newline problem, Writer has method .write(String), which is convenient to use.

What causes this error? "Runtime error 380: Invalid property value"

If you write software, or use software written, which stores program window coordinates or sizes to be resused when starting a program, check there for any occurrence(s) of such sizes and positions which would be causing this. I've seen it time and time again from various vendors lazily producing code which resizes and repositions controls on a "form" (a program window) based on the size of said form. Look in HKLM\Software\Vendor\Program and HKCU\Software\Vendor\Program. Look for specific keys which might be offending. I once had a program store -48000 for the program window position in keys called WindowsPosX and WindowPosY. You could see the program start and running on the taskbar but since the program window itself was smaller than 48000 (the absolute value of -48000), it was positioned completely off the screen. If you're not comfortable with editing regstry information - most people aren't - then uninstall the software, use a registry cleaner to remove any leftover entries then reinstall the software and see if that doesn't fix the problem.

Trim characters in Java

Apache Commons has a great StringUtils class (org.apache.commons.lang.StringUtils). In StringUtils there is a strip(String, String) method that will do what you want.

I highly recommend using Apache Commons anyway, especially the Collections and Lang libraries.

Serializing an object to JSON

Just to keep it backward compatible I load Crockfords JSON-library from cloudflare CDN if no native JSON support is given (for simplicity using jQuery):

function winHasJSON(){
  json_data = JSON.stringify(obj);
  // ... (do stuff with json_data)
}
if(typeof JSON === 'object' && typeof JSON.stringify === 'function'){
  winHasJSON();
} else {
  $.getScript('//cdnjs.cloudflare.com/ajax/libs/json2/20121008/json2.min.js', winHasJSON)
}

Using Position Relative/Absolute within a TD?

With regards to your second attempt, did you try using vertical align ? Either

<td valign="bottom">

or with css

vertical-align:bottom

Dynamically add event listener

I will add a StackBlitz example and a comment to the answer from @tahiche.

The return value is a function to remove the event listener after you have added it. It is considered good practice to remove event listeners when you don't need them anymore. So you can store this return value and call it inside your ngOnDestroy method.

I admit that it might seem confusing at first, but it is actually a very useful feature. How else can you clean up after yourself?

export class MyComponent implements OnInit, OnDestroy {

  public removeEventListener: () => void;

  constructor(
    private renderer: Renderer2, 
    private elementRef: ElementRef
  ) {
  }

  public ngOnInit() {
    this.removeEventListener = this.renderer.listen(this.elementRef.nativeElement, 'click', (event) => {
      if (event.target instanceof HTMLAnchorElement) {
        // Prevent opening anchors the default way
        event.preventDefault();
        // Your custom anchor click event handler
        this.handleAnchorClick(event);
      }
    });
  }

  public ngOnDestroy() {
    this.removeEventListener();
  }
}

You can find a StackBlitz here to show how this could work for catching clicking on anchor elements.

I added a body with an image as follows:
<img src="x" onerror="alert(1)"></div>
to show that the sanitizer is doing its job.

Here in this fiddle you find the same body attached to an innerHTML without sanitizing it and it will demonstrate the issue.

Why do we have to normalize the input for an artificial neural network?

Some inputs to NN might not have a 'naturally defined' range of values. For example, the average value might be slowly, but continuously increasing over time (for example a number of records in the database).

In such case feeding this raw value into your network will not work very well. You will teach your network on values from lower part of range, while the actual inputs will be from the higher part of this range (and quite possibly above range, that the network has learned to work with).

You should normalize this value. You could for example tell the network by how much the value has changed since the previous input. This increment usually can be defined with high probability in a specific range, which makes it a good input for network.

Difference between Visual Basic 6.0 and VBA

Do you want compare VBA with VB-Classic (VB6..) or VB.NET?

VBA (Visual Basic for Applications) is a vb-classic-based script language embedded in Microsoft Office applications. I think it's language features are similar to those of VB5 (it just lacks some few builtin functions), but:

You have access to the office document you wrote the VBA-script for and so you can e.g.

  • Write macros (=automated routines for little recurring tasks in your office-work)
  • Define new functions for excel-cell-formula
  • Process office data

Example: Set the value of an excel-cell

ActiveSheet.Cells("A1").Value = "Foo"

VBC and -.NET are no script languages. You use them to write standalone-applications with separate IDE's which you can't do with VBA (VBA-scripts just "exist" in Office)

VBA has nothing to do with VB.NET (they just have a similar syntax).

Java Try and Catch IOException Problem

The reason you are getting the the IOException is because you are not catching the IOException of your countLines method. You'll want to do something like this:

public static void main(String[] args) {
  int lines = 0;  

  // TODO - Need to get the filename to populate sFileName.  Could
  // come from the command line arguments.

   try {
       lines = LineCounter.countLines(sFileName);
    }
    catch(IOException ex){
        System.out.println (ex.toString());
        System.out.println("Could not find file " + sFileName);
    }

   if(lines > 0) {
     // Do rest of program.
   }
}

How to make a shape with left-top round rounded corner and left-bottom rounded corner?

This bug is filed here. This is a bug of android devices having API level less than 12. You've to put correct versions of your layouts in drawable-v12 folder which will be used for API level 12 or higher. And an erroneous version(corners switched/reversed) of the same layout will be put in the default drawable folder which will be used by the devices having API level less than 12.

For example: I had to design a button with rounded corner at bottom-right.

In 'drawable' folder - button.xml: I had to make bottom-left corner rounded.

<shape>
    <corners android:bottomLeftRadius="15dp"/>
</shape>

In 'drawable-v12' folder - button.xml: Correct version of the layout was placed here to be used for API level 12 or higher.

<shape>
    <corners android:bottomLeftRadius="15dp"/>
</shape>

How to add constraints programmatically using Swift

it is a little different in xcode 7.3.1. this is what i come up with

   // creating the view
        let newView = UIView()
        newView.backgroundColor = UIColor.redColor()
        newView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(newView)

        // creating the constraint 

        // attribute and relation cannot be set directyl you need to create a cariable of them
        let layout11 = NSLayoutAttribute.CenterX
        let layout21 = NSLayoutRelation.Equal
        let layout31 = NSLayoutAttribute.CenterY
        let layout41 = NSLayoutAttribute.Width
        let layout51 = NSLayoutAttribute.Height
        let layout61 = NSLayoutAttribute.NotAnAttribute

        // defining all the constraint
        let horizontalConstraint = NSLayoutConstraint(item: newView, attribute: layout11, relatedBy: layout21, toItem: view, attribute: layout11, multiplier: 1, constant: 0)
        let verticalConstraint = NSLayoutConstraint(item: newView, attribute: layout31, relatedBy: layout21, toItem: view, attribute: layout31, multiplier: 1, constant: 0)
        let widthConstraint = NSLayoutConstraint(item: newView, attribute: layout41, relatedBy: layout21, toItem: nil, attribute: layout61, multiplier: 1, constant: 100)
        let heightConstraint = NSLayoutConstraint(item: newView, attribute: layout51, relatedBy: layout21, toItem: nil, attribute: layout61, multiplier: 1, constant: 100)

        // adding all the constraint
        NSLayoutConstraint.activateConstraints([horizontalConstraint,verticalConstraint,widthConstraint,heightConstraint])

ImportError: DLL load failed: The specified module could not be found

For Windows 10 x64 and Python:

Open a Visual Studio x64 command prompt, and use dumpbin:

dumpbin /dependents [Python Module DLL or PYD file]

If you do not have Visual Studio installed, it is possible to download dumpbin elsewhere, or use another utility such as Dependency Walker.

Note that all other answers (to date) are simply random stabs in the dark, whereas this method is closer to a sniper rifle with night vision.

Case study 1

  1. I switched on Address Sanitizer for a Python module that I wrote using C++ using MSVC and CMake.

  2. It was giving this error: ImportError: DLL load failed: The specified module could not be found

  3. Opened a Visual Studio x64 command prompt.

  4. Under Windows, a .pyd file is a .dll file in disguise, so we want to run dumpbin on this file.

  5. cd MyLibrary\build\lib.win-amd64-3.7\Debug

  6. dumpbin /dependents MyLibrary.cp37-win_amd64.pyd which prints this:

    Microsoft (R) COFF/PE Dumper Version 14.27.29112.0
    Copyright (C) Microsoft Corporation.  All rights reserved.
    
    
    Dump of file MyLibrary.cp37-win_amd64.pyd
    
    File Type: DLL
    
      Image has the following dependencies:
    
        clang_rt.asan_dbg_dynamic-x86_64.dll
        gtestd.dll
        tbb_debug.dll
        python37.dll
        KERNEL32.dll
        MSVCP140D.dll
        VCOMP140D.DLL
        VCRUNTIME140D.dll
        VCRUNTIME140_1D.dll
        ucrtbased.dll
    
      Summary
    
         1000 .00cfg
        D6000 .data
         7000 .idata
        46000 .pdata
       341000 .rdata
        23000 .reloc
         1000 .rsrc
       856000 .text
    
  7. Searched for clang_rt.asan_dbg_dynamic-x86_64.dll, copied it into the same directory, problem solved.

  8. Alternatively, could update the environment variable PATH to point to the directory with the missing .dll.

Please feel free to add your own case studies here! I've made it a community wiki answer.

How can I add a variable to console.log?

When using ES6 you can also do this:

var name = prompt("what is your name?");
console.log(`story ${name} story`);

Note: You need to use backticks `` instead of "" or '' to do it like this.

How to set a cron job to run at a exact time?

You can also specify the exact values for each gr

0 2,10,12,14,16,18,20 * * *

It stands for 2h00, 10h00, 12h00 and so on, till 20h00.

From the above answer, we have:

The comma, ",", means "and". If you are confused by the above line, remember that spaces are the field separators, not commas.

And from (Wikipedia page):

*    *    *    *    *  command to be executed
-    -    -    -    -
¦    ¦    ¦    ¦    ¦
¦    ¦    ¦    ¦    ¦
¦    ¦    ¦    ¦    +----- day of week (0 - 7) (0 or 7 are Sunday, or use names)
¦    ¦    ¦    +---------- month (1 - 12)
¦    ¦    +--------------- day of month (1 - 31)
¦    +-------------------- hour (0 - 23)
+------------------------- min (0 - 59)

Hope it helps :)

--

EDIT:

  • don't miss the 1st 0 (zero) and the following space: it means "the minute zero", you can also set it to 15 (the 15th minute) or expressions like */15 (every minute divisible by 15, i.e. 0,15,30)

Removing padding gutter from grid columns in Bootstrap 4

You can use the mixin make-col-ready and set the gutter width to zero:

@include make-col-ready(0);

VBA copy rows that meet criteria to another sheet

You need to specify workseet. Change line

If Worksheet.Cells(i, 1).Value = "X" Then

to

If Worksheets("Sheet2").Cells(i, 1).Value = "X" Then

UPD:

Try to use following code (but it's not the best approach. As @SiddharthRout suggested, consider about using Autofilter):

Sub LastRowInOneColumn()
   Dim LastRow As Long
   Dim i As Long, j As Long

   'Find the last used row in a Column: column A in this example
   With Worksheets("Sheet2")
      LastRow = .Cells(.Rows.Count, "A").End(xlUp).Row
   End With

   MsgBox (LastRow)
   'first row number where you need to paste values in Sheet1'
   With Worksheets("Sheet1")
      j = .Cells(.Rows.Count, "A").End(xlUp).Row + 1
   End With 

   For i = 1 To LastRow
       With Worksheets("Sheet2")
           If .Cells(i, 1).Value = "X" Then
               .Rows(i).Copy Destination:=Worksheets("Sheet1").Range("A" & j)
               j = j + 1
           End If
       End With
   Next i
End Sub

Html.Textbox VS Html.TextboxFor

The TextBoxFor is a newer MVC input extension introduced in MVC2.

The main benefit of the newer strongly typed extensions is to show any errors / warnings at compile-time rather than runtime.

See this page.

http://weblogs.asp.net/scottgu/archive/2010/01/10/asp-net-mvc-2-strongly-typed-html-helpers.aspx

How to find difference between two columns data?

IF the table is alias t

SELECT t.Present , t.previous, t.previous- t.Present AS Difference
FROM   temp1 as t

How To Include CSS and jQuery in my WordPress plugin?

You can use the following function to enqueue script or style from plugin.

function my_enqueued_assets() {
    wp_enqueue_script('my-js-file', plugin_dir_url(__FILE__) . '/js/script.js', '', time());
    wp_enqueue_style('my-css-file', plugin_dir_url(__FILE__) . '/css/style.css', '', time());
}
add_action('wp_enqueue_scripts', 'my_enqueued_assets');

Can not find the tag library descriptor of springframework

you have to add the dependency for springs mvc

tray adding that in your pom

<!-- mvc -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>3.1.2.RELEASE</version>
</dependency>

How to use goto statement correctly

If you look up continue and break they accept a "Label". Experiment with that. Goto itself won't work.

public class BreakContinueWithLabel {

    public static void main(String args[]) {

        int[] numbers= new int[]{100,18,21,30};

        //Outer loop checks if number is multiple of 2
        OUTER:  //outer label
        for(int i = 0; i<numbers.length; i++){
            if(i % 2 == 0){
                System.out.println("Odd number: " + i +
                                   ", continue from OUTER label");
                continue OUTER;
            }

            INNER:
            for(int j = 0; j<numbers.length; j++){
                System.out.println("Even number: " + i +
                                   ", break  from INNER label");
                break INNER;
            }
        }      
    }
}

Read more

How to add one column into existing SQL Table

What about something like:

Alter Table Products
Add LastUpdate varchar(200) null

Do you need something more complex than this?

Iterating through map in template

Check the Variables section in the Go template docs. A range may declare two variables, separated by a comma. The following should work:

{{ range $key, $value := . }}
   <li><strong>{{ $key }}</strong>: {{ $value }}</li>
{{ end }}

When should I use git pull --rebase?

git pull --rebase may hide a history rewriting from a collaborator git push --force. I recommend to use git pull --rebase only if you know you forgot to push your commits before someone else does the same.

If you did not commit anything, but your working space is not clean, just git stash before to git pull. This way you won't silently rewrite your history (which could silently drop some of your work).

Vertically and horizontally centering text in circle in CSS (like iphone notification badge)

Here is an example of flat badges that play well with zurb foundation css framework
Note: you might have to adjust the height for different fonts.

http://jsfiddle.net/jamesharrington/xqr5nx1o/

The Magic sauce!

.label {
  background:#EA2626;
  display:inline-block;
  border-radius: 12px;
  color: white;
  font-weight: bold;
  height: 17px; 
  padding: 2px 3px 2px 3px;
  text-align: center;
  min-width: 16px;
}

Remove duplicated rows

The data.table package also has unique and duplicated methods of it's own with some additional features.

Both the unique.data.table and the duplicated.data.table methods have an additional by argument which allows you to pass a character or integer vector of column names or their locations respectively

library(data.table)
DT <- data.table(id = c(1,1,1,2,2,2),
                 val = c(10,20,30,10,20,30))

unique(DT, by = "id")
#    id val
# 1:  1  10
# 2:  2  10

duplicated(DT, by = "id")
# [1] FALSE  TRUE  TRUE FALSE  TRUE  TRUE

Another important feature of these methods is a huge performance gain for larger data sets

library(microbenchmark)
library(data.table)
set.seed(123)
DF <- as.data.frame(matrix(sample(1e8, 1e5, replace = TRUE), ncol = 10))
DT <- copy(DF)
setDT(DT)

microbenchmark(unique(DF), unique(DT))
# Unit: microseconds
#       expr       min         lq      mean    median        uq       max neval cld
# unique(DF) 44708.230 48981.8445 53062.536 51573.276 52844.591 107032.18   100   b
# unique(DT)   746.855   776.6145  2201.657   864.932   919.489  55986.88   100  a 


microbenchmark(duplicated(DF), duplicated(DT))
# Unit: microseconds
#           expr       min         lq       mean     median        uq        max neval cld
# duplicated(DF) 43786.662 44418.8005 46684.0602 44925.0230 46802.398 109550.170   100   b
# duplicated(DT)   551.982   558.2215   851.0246   639.9795   663.658   5805.243   100  a 

jQuery: selecting each td in a tr

You can simply do the following inside your TR loop:

$(this).find('td').each (function() {
  // do your cool stuff
});                          

Better way to check if a Path is a File or a Directory?

This was the best I could come up with given the behavior of the Exists and Attributes properties:

using System.IO;

public static class FileSystemInfoExtensions
{
    /// <summary>
    /// Checks whether a FileInfo or DirectoryInfo object is a directory, or intended to be a directory.
    /// </summary>
    /// <param name="fileSystemInfo"></param>
    /// <returns></returns>
    public static bool IsDirectory(this FileSystemInfo fileSystemInfo)
    {
        if (fileSystemInfo == null)
        {
            return false;
        }

        if ((int)fileSystemInfo.Attributes != -1)
        {
            // if attributes are initialized check the directory flag
            return fileSystemInfo.Attributes.HasFlag(FileAttributes.Directory);
        }

        // If we get here the file probably doesn't exist yet.  The best we can do is 
        // try to judge intent.  Because directories can have extensions and files
        // can lack them, we can't rely on filename.
        // 
        // We can reasonably assume that if the path doesn't exist yet and 
        // FileSystemInfo is a DirectoryInfo, a directory is intended.  FileInfo can 
        // make a directory, but it would be a bizarre code path.

        return fileSystemInfo is DirectoryInfo;
    }
}

Here's how it tests out:

    [TestMethod]
    public void IsDirectoryTest()
    {
        // non-existing file, FileAttributes not conclusive, rely on type of FileSystemInfo
        const string nonExistentFile = @"C:\TotallyFakeFile.exe";

        var nonExistentFileDirectoryInfo = new DirectoryInfo(nonExistentFile);
        Assert.IsTrue(nonExistentFileDirectoryInfo.IsDirectory());

        var nonExistentFileFileInfo = new FileInfo(nonExistentFile);
        Assert.IsFalse(nonExistentFileFileInfo.IsDirectory());

        // non-existing directory, FileAttributes not conclusive, rely on type of FileSystemInfo
        const string nonExistentDirectory = @"C:\FakeDirectory";

        var nonExistentDirectoryInfo = new DirectoryInfo(nonExistentDirectory);
        Assert.IsTrue(nonExistentDirectoryInfo.IsDirectory());

        var nonExistentFileInfo = new FileInfo(nonExistentDirectory);
        Assert.IsFalse(nonExistentFileInfo.IsDirectory());

        // Existing, rely on FileAttributes
        const string existingDirectory = @"C:\Windows";

        var existingDirectoryInfo = new DirectoryInfo(existingDirectory);
        Assert.IsTrue(existingDirectoryInfo.IsDirectory());

        var existingDirectoryFileInfo = new FileInfo(existingDirectory);
        Assert.IsTrue(existingDirectoryFileInfo.IsDirectory());

        // Existing, rely on FileAttributes
        const string existingFile = @"C:\Windows\notepad.exe";

        var existingFileDirectoryInfo = new DirectoryInfo(existingFile);
        Assert.IsFalse(existingFileDirectoryInfo.IsDirectory());

        var existingFileFileInfo = new FileInfo(existingFile);
        Assert.IsFalse(existingFileFileInfo.IsDirectory());
    }

How to kill a while loop with a keystroke?

There is a solution that requires no non-standard modules and is 100% transportable

import thread

def input_thread(a_list):
    raw_input()
    a_list.append(True)

def do_stuff():
    a_list = []
    thread.start_new_thread(input_thread, (a_list,))
    while not a_list:
        stuff()

How can I detect when the mouse leaves the window?

If you are using jQuery then how about this short and sweet code -

$(document).mouseleave(function () {
    console.log('out');
});

This event will trigger whenever the mouse is not in your page as you want. Just change the function to do whatever you want.

And you could also use:

$(document).mouseenter(function () {
    console.log('in');
});

To trigger when the mouse enters back to the page again.

Source: https://stackoverflow.com/a/16029966/895724

How can I get a JavaScript stack trace when I throw an exception?

Note that chromium/chrome (other browsers using V8), and also Firefox do have a convenient interface to get a stacktrace through a stack property on Error objects.

try {
   // Code throwing an exception
} catch(e) {
  console.log(e.stack);
}

It applies for the base exceptions as well as for the ones you throw yourself. (Considered that you use the Error class, which is anyway a good practice).

See details on V8 documentation

Allow multi-line in EditText view in Android?

Try this, add these lines to your edit text view, i'll add mine. make sure you understand it

android:overScrollMode="always"
android:scrollbarStyle="insideInset"
android:scrollbars="vertical"

<EditText
    android:inputType="textMultiLine"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/editText_newprom_description"
    android:padding="10dp"
    android:lines="5"
    android:overScrollMode="always"
    android:scrollbarStyle="insideInset"
    android:minLines="5"
    android:gravity="top|left"
    android:scrollbars="vertical"
    android:layout_marginBottom="20dp"/>

and on your java class make on click listner to this edit text as follows, i'll add mine, chane names according to yours.

EditText description;
description = (EditText)findViewById(R.id.editText_newprom_description);

description.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {

                view.getParent().requestDisallowInterceptTouchEvent(true);
                switch (motionEvent.getAction() & MotionEvent.ACTION_MASK){
                    case MotionEvent.ACTION_UP:
                        view.getParent().requestDisallowInterceptTouchEvent(false);
                        break;
                }

                return false;
            }

        });

this works fine for me

How can I do an OrderBy with a dynamic string parameter?

I did so:

using System.Linq.Expressions;

namespace System.Linq
{
    public static class LinqExtensions
    {

        public static IOrderedQueryable<TSource> OrderBy<TSource>(this IQueryable<TSource> source, string field, string dir = "asc")
        {
            // parametro => expressão
            var parametro = Expression.Parameter(typeof(TSource), "r");
            var expressao = Expression.Property(parametro, field);
            var lambda = Expression.Lambda(expressao, parametro); // r => r.AlgumaCoisa
            var tipo = typeof(TSource).GetProperty(field).PropertyType;

            var nome = "OrderBy";
            if (string.Equals(dir, "desc", StringComparison.InvariantCultureIgnoreCase))
            {
                nome = "OrderByDescending";
            }
            var metodo = typeof(Queryable).GetMethods().First(m => m.Name == nome && m.GetParameters().Length == 2);
            var metodoGenerico = metodo.MakeGenericMethod(new[] { typeof(TSource), tipo });
            return metodoGenerico.Invoke(source, new object[] { source, lambda }) as IOrderedQueryable<TSource>;

        }

        public static IOrderedQueryable<TSource> ThenBy<TSource>(this IOrderedQueryable<TSource> source, string field, string dir = "asc")
        {
            var parametro = Expression.Parameter(typeof(TSource), "r");
            var expressao = Expression.Property(parametro, field);
            var lambda = Expression.Lambda<Func<TSource, string>>(expressao, parametro); // r => r.AlgumaCoisa
            var tipo = typeof(TSource).GetProperty(field).PropertyType;

            var nome = "ThenBy";
            if (string.Equals(dir, "desc", StringComparison.InvariantCultureIgnoreCase))
            {
                nome = "ThenByDescending";
            }

            var metodo = typeof(Queryable).GetMethods().First(m => m.Name == nome && m.GetParameters().Length == 2);
            var metodoGenerico = metodo.MakeGenericMethod(new[] { typeof(TSource), tipo });
            return metodoGenerico.Invoke(source, new object[] { source, lambda }) as IOrderedQueryable<TSource>;
        }

    }
}

Use :

example.OrderBy("Nome", "desc").ThenBy("other")

Work like:

example.OrderByDescending(r => r.Nome).ThenBy(r => r.other)

The Use of Multiple JFrames: Good or Bad Practice?

Bad practice definitely. One reason is that it is not very 'user-friendly' for the fact that every JFrame shows a new taskbar icon. Controlling multiple JFrames will have you ripping your hair out.

Personally, I would use ONE JFrame for your kind of application. Methods of displaying multiple things is up to you, there are many. Canvases, JInternalFrame, CardLayout, even JPanels possibly.

Multiple JFrame objects = Pain, trouble, and problems.

Unable to load script from assets index.android.bundle on windows

For this problem I just solve it by running:

react-native start

then

adb reverse tcp:8081 tcp:8081

on command line. And then i can run:

react-native run-android

So i will not waste my time to run:

react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res

every time.

How do I search for a pattern within a text file using Python combining regex & string/file operations and store instances of the pattern?

import re
pattern = re.compile("<(\d{4,5})>")

for i, line in enumerate(open('test.txt')):
    for match in re.finditer(pattern, line):
        print 'Found on line %s: %s' % (i+1, match.group())

A couple of notes about the regex:

  • You don't need the ? at the end and the outer (...) if you don't want to match the number with the angle brackets, but only want the number itself
  • It matches either 4 or 5 digits between the angle brackets

Update: It's important to understand that the match and capture in a regex can be quite different. The regex in my snippet above matches the pattern with angle brackets, but I ask to capture only the internal number, without the angle brackets.

More about regex in python can be found here : Regular Expression HOWTO

Good NumericUpDown equivalent in WPF?

If commercial solutions are ok, you may consider this control set: WPF Elements by Mindscape

It contains such a spin control and alternatively (my personal preference) a spin-decorator, that can decorate various numeric controls (like IntegerTextBox, NumericTextBox, also part of the control set) in XAML like this:

<WpfElements:SpinDecorator>
   <WpfElements:IntegerTextBox Text="{Binding Foo}" />
</WpfElements:SpinDecorator>

Javascript : array.length returns undefined

An easy fix to this question is to add '[' in the start of your json file, and ending it with a ']'. This solved it for me.

Regular expression replace in C#

Try this::

sb_trim = Regex.Replace(stw, @"(\D+)\s+\$([\d,]+)\.\d+\s+(.)",
    m => string.Format(
        "{0},{1},{2}",
        m.Groups[1].Value,
        m.Groups[2].Value.Replace(",", string.Empty),
        m.Groups[3].Value));

This is about as clean an answer as you'll get, at least with regexes.

  • (\D+): First capture group. One or more non-digit characters.
  • \s+\$: One or more spacing characters, then a literal dollar sign ($).
  • ([\d,]+): Second capture group. One or more digits and/or commas.
  • \.\d+: Decimal point, then at least one digit.
  • \s+: One or more spacing characters.
  • (.): Third capture group. Any non-line-breaking character.

The second capture group additionally needs to have its commas stripped. You could do this with another regex, but it's really unnecessary and bad for performance. This is why we need to use a lambda expression and string format to piece together the replacement. If it weren't for that, we could just use this as the replacement, in place of the lambda expression:

"$1,$2,$3"

exception in thread 'main' java.lang.NoClassDefFoundError:

I spent four hours trying various permutations & search suggestions.

At last, found this post that worked but not the best solution to change the original code to test it.

  1. Tried changing CLASSPATH, to include class libraries, set classpath=JDKbin;JDKlib;JREbin;JRElib;myClassLib;.
  2. Changed the current directory to parent directory(package folder) and tired java <packageName>.<className> also tried the java ..\<packageName>.<className>

Neither worked.

However first response alone worked. Thank you so much Abhi!!!

"I found one another common reason. If you create the java file inside a package using IDE like eclipse, you will find the package name on the top of your java file like "package pkgName". If you try to run this file from command prompt, you will get the NoClassDefFoundError error. Remove the package name from the java file and use the commands in the command prompt. Wasted 3 hours for this. -- Abhi"

Curious if there is any other way to make it work without having to change the original code? Thank you!

HTML5 image icon to input placeholder

Adding to Tim's answer:

  #search:placeholder-shown {
     // show background image, I like svg 
     // when using svg, do not use HEX for colour; you can use rbg/a instead
     // also notice the single quotes
     background-image url('data:image/svg+xml; utf8, <svg>... <g fill="grey"...</svg>')
     // other background props
   }

   #search:not(:placeholder-shown) { background-image: none;}

Days between two dates?

Do you mean full calendar days, or groups of 24 hours?

For simply 24 hours, assuming you're using Python's datetime, then the timedelta object already has a days property:

days = (a - b).days

For calendar days, you'll need to round a down to the nearest day, and b up to the nearest day, getting rid of the partial day on either side:

roundedA = a.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
roundedB = b.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
days = (roundedA - roundedB).days

Fully custom validation error message with Rails

Here is my code that can be useful for you in case you still need it: My model:

validates :director, acceptance: {message: "^Please confirm that you are a director of the company."}, on: :create, if: :is_director?

Then I have created a helper to show messages:

module ErrorHelper
  def error_messages!
    return "" unless error_messages?
    messages = resource.errors.full_messages.map { |msg|
       if msg.present? && !msg.index("^").nil?
         content_tag(:p, msg.slice((msg.index("^")+1)..-1))
       else
         content_tag(:p, msg)
       end
    }.join

    html = <<-HTML
      <div class="general-error alert show">
        #{messages}
      </div>
    HTML

    html.html_safe
  end

  def error_messages?
    !resource.errors.empty?
  end
end

How can I match a string with a regex in Bash?

To match regexes you need to use the =~ operator.

Try this:

[[ sed-4.2.2.tar.bz2 =~ tar.bz2$ ]] && echo matched

Alternatively, you can use wildcards (instead of regexes) with the == operator:

[[ sed-4.2.2.tar.bz2 == *tar.bz2 ]] && echo matched

If portability is not a concern, I recommend using [[ instead of [ or test as it is safer and more powerful. See What is the difference between test, [ and [[ ? for details.

Converting BitmapImage to Bitmap and vice versa

I've just been trying to use the above in my code and I believe that there is a problem with the Bitmap2BitmapImage function (and possibly the other one as well).

using (MemoryStream ms = new MemoryStream())

Does the above line result in the stream being disposed of? Which means that the returned BitmapImage loses its content.

As I'm a WPF newbie I'm not sure that this is the correct technical explanation, but the code didn't work in my application until I removed the using directive.

Setting Curl's Timeout in PHP

You can't run the request from a browser, it will timeout waiting for the server running the CURL request to respond. The browser is probably timing out in 1-2 minutes, the default network timeout.

You need to run it from the command line/terminal.

error opening trace file: No such file or directory (2)

Try removing the uses-sdk part form AndroidManifest.xml file. it worked for me!

Don't use the Android Virtual Device with too low configuration. Let it be medium.

Two onClick actions one button

<input type="button" value="..." onClick="fbLikeDump(); WriteCookie();" />

Apache is "Unable to initialize module" because of module's and PHP's API don't match after changing the PHP configuration

What worked for me was simply to do the following:

open the php.ini file.

Under the DYNAMIC EXTENSIONS heading, comment out the following line as

;extension=php_java.dll

Restarted Apache and all was fine

How do you tell if a string contains another string in POSIX sh?

In special cases where you want to find whether a word is contained in a long text, you can iterate through the long text with a loop.

found=F
query_word=this
long_string="many many words in this text"
for w in $long_string; do
    if [ "$w" = "$query_word" ]; then
          found=T
          break
    fi
done

This is pure Bourne shell.

Clear contents of cells in VBA using column reference

The issue is not with the with statement, it is on the Range function, it doesn't accept the absolute cell value.. it should be like Range("A4:B100").. you can refer the following thread for reference..

following code should work.. Convert cells(1,1) into "A1" and vice versa

LastColData = Sheets(WSNAME).Range("A4").End(xlToRight).Column
            LastRowData = Sheets(WSNAME).Range("A4").End(xlDown).Row
            Rng = "A4:" & Sheets(WSNAME).Cells(LastRowData, LastColData).Address(RowAbsolute:=False, ColumnAbsolute:=False)

 Worksheets(WSNAME).Range(Rng).ClearContents

how to change the dist-folder path in angular-cli after 'ng build'

for github pages I Use

ng build --prod --base-href "https://<username>.github.io/<RepoName>/" --output-path=docs

This is what that copies output into the docs folder : --output-path=docs

Print all day-dates between two dates

import datetime

begin = datetime.date(2008, 8, 15)
end = datetime.date(2008, 9, 15)

next_day = begin
while True:
    if next_day > end:
        break
    print next_day
    next_day += datetime.timedelta(days=1)

Setting the number of map tasks and reduce tasks

Folks from this theory it seems we cannot run map reduce jobs in parallel.

Lets say I configured total 5 mapper jobs to run on particular node.Also I want to use this in such a way that JOB1 can use 3 mappers and JOB2 can use 2 mappers so that job can run in parallel. But above properties are ignored then how can execute jobs in parallel.

What is an example of the Liskov Substitution Principle?

The LSP is a rule about the contract of the clases: if a base class satisfies a contract, then by the LSP derived classes must also satisfy that contract.

In Pseudo-python

class Base:
   def Foo(self, arg): 
       # *... do stuff*

class Derived(Base):
   def Foo(self, arg):
       # *... do stuff*

satisfies LSP if every time you call Foo on a Derived object, it gives exactly the same results as calling Foo on a Base object, as long as arg is the same.

how to change a selections options based on another select option selected?

as a complementary answer to @Navid_pdp11, which will enable to select the first visible item and work on document load as well. put the following below your body tag

<script>
$('#mainCat').on('change', function() {
    let selected = $(this).val();
    $("#expertCat option").each(function(){
        let element =  $(this) ;
        if (element.data("tag") != selected){
            element.removeClass('visible');
            element.addClass('hidden');
            element.hide() ;
        }else{
            element.removeClass('hidden');
            element.addClass('visible');
            element.show();
        }
    });
    let expertCat = $('#expertCat');
    expertCat.prop('selectedIndex',expertCat.find("option.visible:eq(0)").index());
}).triggerHandler('change');
</script>

How to convert a ruby hash object to JSON?

Add the following line on the top of your file

require 'json'

Then you can use:

car = {:make => "bmw", :year => "2003"}
car.to_json

Alternatively, you can use:

JSON.generate({:make => "bmw", :year => "2003"})

Creating multiple objects with different names in a loop to store in an array list

You can use this code...

public class Main {

    public static void main(String args[]) {
        String[] names = {"First", "Second", "Third"};//You Can Add More Names
        double[] amount = {20.0, 30.0, 40.0};//You Can Add More Amount
        List<Customer> customers = new ArrayList<Customer>();
        int i = 0;
        while (i < names.length) {
            customers.add(new Customer(names[i], amount[i]));
            i++;
        }
    }
}

how to show lines in common (reverse diff)?

Was asked here before: Unix command to find lines common in two files

You could also try with perl (credit goes here)

perl -ne 'print if ($seen{$_} .= @ARGV) =~ /10$/'  file1 file2

Check if at least two out of three booleans are true

Readability should be the goal. Someone who reads the code must understand your intent immediately. So here is my solution.

int howManyBooleansAreTrue =
      (a ? 1 : 0)
    + (b ? 1 : 0)
    + (c ? 1 : 0);

return howManyBooleansAreTrue >= 2;

YouTube embedded video: set different thumbnail

I was having trouble with the autoplay from waldir's solution... using autoplay, the video was playing when the page loaded, not when the div got displayed.

This solution worked for me except I replaced

<a class="introVid" href="#video">Watch the video</a></p>

with

<a class="introVid" href="#video"><img src="images/NEWTHUMB.jpg" style="cursor:pointer" /></a>

so that it would use my thumbnail in place of the text link.

How do I detach objects in Entity Framework Code First?

If you want to detach existing object follow @Slauma's advice. If you want to load objects without tracking changes use:

var data = context.MyEntities.AsNoTracking().Where(...).ToList();

As mentioned in comment this will not completely detach entities. They are still attached and lazy loading works but entities are not tracked. This should be used for example if you want to load entity only to read data and you don't plan to modify them.

SQL statement to select all rows from previous day

SELECT * from table_name where date_field = DATE_SUB(CURRENT_DATE(),INTERVAL 1 DAY);

Spring Data: "delete by" is supported?

here follows my 2 cents. You can also use native queries, like:

@Modifying
@Query(value="delete from rreo r where r.cod_ibge = ?1 and r.exercicio= ?2", nativeQuery = true)
void deleteByParameters(Integer codIbge, Integer exercicio);

Using os.walk() to recursively traverse directories in Python

#!/usr/bin/python

import os 

def tracing(a):
    global i>
    for item in os.listdir(a):
        if os.path.isfile(item):
            print i + item 
        else:
            print i + item 
            i+=i
            tracing(item)

i = "---"
tracing(".")

How to create duplicate table with new name in SQL Server 2008

Right click on the table in SQL Management Studio.

Select Script... Create to... New Query Window.

This will generate a script to recreate the table in a new query window.

Change the name of the table in the script to whatever you want the new table to be named.

Execute the script.

How to run a single RSpec test?

Another common mistake is to still have or have upgraded an older Rails app to Rails 5+ and be putting require 'spec_helper' at the top of each test file. This should changed to require 'rails_helper'. If you are seeing different behavior between the rake task (rake spec) and when you run a single spec (rspec path/to/spec.rb), this is a common reason

the best solution is to

1) make sure you are using require 'rails_helper' at the top of each of your spec files — not the older-style require 'spec_helper' 2) use the rake spec SPEC=path/to/spec.rb syntax

the older-style rspec path/to/spec.rb I think should be considered out-of-vogue by the community at this time in 2020 (but of course you will get it to work, other considerations aside)

How to "wait" a Thread in Android

You need the sleep method of the Thread class.

public static void sleep (long time)

Causes the thread which sent this message to sleep for the given interval of time (given in milliseconds). The precision is not guaranteed - the Thread may sleep more or less than requested.

Parameters

time The time to sleep in milliseconds.

How does BitLocker affect performance?

I am talking here from a theoretical point of view; I have not tried BitLocker.

BitLocker uses AES encryption with a 128-bit key. On a Core2 machine, clocked at 2.53 GHz, encryption speed should be about 110 MB/s, using one core. The two cores could process about 220 MB/s, assuming perfect data transfer and core synchronization with no overhead, and that nothing requires the CPU in the same time (that one hell of an assumption, actually). The X25-M G2 is announced at 250 MB/s read bandwidth (that's what the specs say), so, in "ideal" conditions, BitLocker necessarily involves a bit of a slowdown.

However read bandwidth is not that important. It matters when you copy huge files, which is not something that you do very often. In everyday work, access time is much more important: as a developer, you create, write, read and delete many files, but they are all small (most of them are much smaller than one megabyte). This is what makes SSD "snappy". Encryption does not impact access time. So my guess is that any performance degradation will be negligible(*).

(*) Here I assume that Microsoft's developers did their job properly.

Javascript loading CSV file into an array

You can't use AJAX to fetch files from the user machine. This is absolutely the wrong way to go about it.

Use the FileReader API:

<input type="file" id="file input">

js:

console.log(document.getElementById("file input").files); // list of File objects

var file = document.getElementById("file input").files[0];
var reader = new FileReader();
content = reader.readAsText(file);
console.log(content);

Then parse content as CSV. Keep in mind that your parser currently does not deal with escaped values in CSV like: value1,value2,"value 3","value ""4"""

What is the problem with shadowing names defined in outer scopes?

The currently most up-voted and accepted answer and most answers here miss the point.

It doesn't matter how long your function is, or how you name your variable descriptively (to hopefully minimize the chance of potential name collision).

The fact that your function's local variable or its parameter happens to share a name in the global scope is completely irrelevant. And in fact, no matter how carefully you choose you local variable name, your function can never foresee "whether my cool name yadda will also be used as a global variable in future?". The solution? Simply don't worry about that! The correct mindset is to design your function to consume input from and only from its parameters in signature. That way you don't need to care what is (or will be) in global scope, and then shadowing becomes not an issue at all.

In other words, the shadowing problem only matters when your function need to use the same name local variable and the global variable. But you should avoid such design in the first place. The OP's code does not really have such design problem. It is just that PyCharm is not smart enough and it gives out a warning just in case. So, just to make PyCharm happy, and also make our code clean, see this solution quoting from silyevsk's answer to remove the global variable completely.

def print_data(data):
    print data

def main():
    data = [4, 5, 6]
    print_data(data)

main()

This is the proper way to "solve" this problem, by fixing/removing your global thing, not adjusting your current local function.

Sending and receiving UDP packets?

The receiver must set port of receiver to match port set in sender DatagramPacket. For debugging try listening on port > 1024 (e.g. 8000 or 9000). Ports < 1024 are typically used by system services and need admin access to bind on such a port.

If the receiver sends packet to the hard-coded port it's listening to (e.g. port 57) and the sender is on the same machine then you would create a loopback to the receiver itself. Always use the port specified from the packet and in case of production software would need a check in any case to prevent such a case.

Another reason a packet won't get to destination is the wrong IP address specified in the sender. UDP unlike TCP will attempt to send out a packet even if the address is unreachable and the sender will not receive an error indication. You can check this by printing the address in the receiver as a precaution for debugging.

In the sender you set:

 byte [] IP= { (byte)192, (byte)168, 1, 106 };
 InetAddress address = InetAddress.getByAddress(IP);

but might be simpler to use the address in string form:

 InetAddress address = InetAddress.getByName("192.168.1.106");

In other words, you set target as 192.168.1.106. If this is not the receiver then you won't get the packet.

Here's a simple UDP Receiver that works :

import java.io.IOException;
import java.net.*;

public class Receiver {

    public static void main(String[] args) {
        int port = args.length == 0 ? 57 : Integer.parseInt(args[0]);
        new Receiver().run(port);
    }

    public void run(int port) {    
      try {
        DatagramSocket serverSocket = new DatagramSocket(port);
        byte[] receiveData = new byte[8];
        String sendString = "polo";
        byte[] sendData = sendString.getBytes("UTF-8");

        System.out.printf("Listening on udp:%s:%d%n",
                InetAddress.getLocalHost().getHostAddress(), port);     
        DatagramPacket receivePacket = new DatagramPacket(receiveData,
                           receiveData.length);

        while(true)
        {
              serverSocket.receive(receivePacket);
              String sentence = new String( receivePacket.getData(), 0,
                                 receivePacket.getLength() );
              System.out.println("RECEIVED: " + sentence);
              // now send acknowledgement packet back to sender     
              DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length,
                   receivePacket.getAddress(), receivePacket.getPort());
              serverSocket.send(sendPacket);
        }
      } catch (IOException e) {
              System.out.println(e);
      }
      // should close serverSocket in finally block
    }
}

Ant is using wrong java version

According to the ant manual, setting JAVA_HOME should work - are you sure the changed setting is visible to ant?

Alternatively, you could use the JAVACMD variable.

How to get the first non-null value in Java?

How about using suppliers when you want to avoid evaluating some expensive method?

Like this:

public static <T> T coalesce(Supplier<T>... items) {
for (Supplier<T> item : items) {
    T value = item.get();
    if (value != null) {
        return value;
    }
    return null;
}

And then using it like this:

Double amount = coalesce(order::firstAmount, order::secondAmount, order::thirdAmount)

You can also use overloaded methods for the calls with two, three or four arguments.

In addition, you could also use streams with something like this:

public static <T> T coalesce2(Supplier<T>... s) {
    return Arrays.stream(s).map(Supplier::get).filter(Objects::nonNull).findFirst().orElse(null);
}

Get checkbox list values with jQuery

Try this one..

var listCheck = [];
console.log($("input[name='YourCheckBokName[]']"));
$("input[name='YourCheckBokName[]']:checked").each(function() {
     console.log($(this).val());
     listCheck .push($(this).val());
});
console.log(listCheck);

Code-first vs Model/Database-first

Database first approach example:

Without writing any code: ASP.NET MVC / MVC3 Database First Approach / Database first

And I think it is better than other approaches because data loss is less with this approach.

Python, HTTPS GET with basic authentication

Based on the @AndrewCox 's answer with some minor improvements:

from http.client import HTTPSConnection
from base64 import b64encode


client = HTTPSConnection("www.google.com")
user = "user_name"
password = "password"
headers = {
    "Authorization": "Basic {}".format(
        b64encode(bytes(f"{user}:{password}", "utf-8")).decode("ascii")
    )
}
client.request('GET', '/', headers=headers)
res = client.getresponse()
data = res.read()

Note, you should set encoding if you use bytes function instead of b"".

milliseconds to time in javascript

Here is a filter that use:

app.filter('milliSecondsToTimeCode', function () {
    return function msToTime(duration) {
        var milliseconds = parseInt((duration % 1000) / 100)
            , seconds = parseInt((duration / 1000) % 60)
            , minutes = parseInt((duration / (1000 * 60)) % 60)
            , hours = parseInt((duration / (1000 * 60 * 60)) % 24);

        hours = (hours < 10) ? "0" + hours : hours;
        minutes = (minutes < 10) ? "0" + minutes : minutes;
        seconds = (seconds < 10) ? "0" + seconds : seconds;

        return hours + ":" + minutes + ":" + seconds + "." + milliseconds;
    };
});

Just add it to your expression as such

{{milliseconds | milliSecondsToTimeCode}}

How to get commit history for just one branch?

I know it's very late for this one... But here is a (not so simple) oneliner to get what you were looking for:

git show-branch --all 2>/dev/null | grep -E "\[$(git branch | grep -E '^\*' | awk '{ printf $2 }')" | tail -n+2 | sed -E "s/^[^\[]*?\[/[/"
  • We are listing commits with branch name and relative positions to actual branch states with git show-branch (sending the warnings to /dev/null).
  • Then we only keep those with our branch name inside the bracket with grep -E "\[$BRANCH_NAME".
  • Where actual $BRANCH_NAME is obtained with git branch | grep -E '^\*' | awk '{ printf $2 }' (the branch with a star, echoed without that star).
  • From our results, we remove the redundant line at the beginning with tail -n+2.
  • And then, we fianlly clean up the output by removing everything preceding [$BRANCH_NAME] with sed -E "s/^[^\[]*?\[/[/".

CSS smooth bounce animation

The long rest in between is due to your keyframe settings. Your current keyframe rules mean that the actual bounce happens only between 40% - 60% of the animation duration (that is, between 1s - 1.5s mark of the animation). Remove those rules and maybe even reduce the animation-duration to suit your needs.

_x000D_
_x000D_
.animated {_x000D_
  -webkit-animation-duration: .5s;_x000D_
  animation-duration: .5s;_x000D_
  -webkit-animation-fill-mode: both;_x000D_
  animation-fill-mode: both;_x000D_
  -webkit-animation-timing-function: linear;_x000D_
  animation-timing-function: linear;_x000D_
  animation-iteration-count: infinite;_x000D_
  -webkit-animation-iteration-count: infinite;_x000D_
}_x000D_
@-webkit-keyframes bounce {_x000D_
  0%, 100% {_x000D_
    -webkit-transform: translateY(0);_x000D_
  }_x000D_
  50% {_x000D_
    -webkit-transform: translateY(-5px);_x000D_
  }_x000D_
}_x000D_
@keyframes bounce {_x000D_
  0%, 100% {_x000D_
    transform: translateY(0);_x000D_
  }_x000D_
  50% {_x000D_
    transform: translateY(-5px);_x000D_
  }_x000D_
}_x000D_
.bounce {_x000D_
  -webkit-animation-name: bounce;_x000D_
  animation-name: bounce;_x000D_
}_x000D_
#animated-example {_x000D_
  width: 20px;_x000D_
  height: 20px;_x000D_
  background-color: red;_x000D_
  position: relative;_x000D_
  top: 100px;_x000D_
  left: 100px;_x000D_
  border-radius: 50%;_x000D_
}_x000D_
hr {_x000D_
  position: relative;_x000D_
  top: 92px;_x000D_
  left: -300px;_x000D_
  width: 200px;_x000D_
}
_x000D_
<div id="animated-example" class="animated bounce"></div>_x000D_
<hr>
_x000D_
_x000D_
_x000D_


Here is how your original keyframe settings would be interpreted by the browser:

  • At 0% (that is, at 0s or start of animation) - translate by 0px in Y axis.
  • At 20% (that is, at 0.5s of animation) - translate by 0px in Y axis.
  • At 40% (that is, at 1s of animation) - translate by 0px in Y axis.
  • At 50% (that is, at 1.25s of animation) - translate by 5px in Y axis. This results in a gradual upward movement.
  • At 60% (that is, at 1.5s of animation) - translate by 0px in Y axis. This results in a gradual downward movement.
  • At 80% (that is, at 2s of animation) - translate by 0px in Y axis.
  • At 100% (that is, at 2.5s or end of animation) - translate by 0px in Y axis.

Set UILabel line spacing

You can control line spacing in the storyboard:

duplicate question

json Uncaught SyntaxError: Unexpected token :

That hex might need to be wrapped in quotes and made into a string. Javascript might not like the # character

Simple file write function in C++

This is a place in which C++ has a strange rule. Before being able to compile a call to a function the compiler must know the function name, return value and all parameters. This can be done by adding a "prototype". In your case this simply means adding before main the following line:

int writeFile();

this tells the compiler that there exist a function named writeFile that will be defined somewhere, that returns an int and that accepts no parameters.

Alternatively you can define first the function writeFile and then main because in this case when the compiler gets to main already knows your function.

Note that this requirement of knowing in advance the functions being called is not always applied. For example for class members defined inline it's not required...

struct Foo {
    void bar() {
        if (baz() != 99) {
            std::cout << "Hey!";
        }
    }

    int baz() {
        return 42;
    }
};

In this case the compiler has no problem analyzing the definition of bar even if it depends on a function baz that is declared later in the source code.

Python Pip install Error: Unable to find vcvarsall.bat. Tried all solutions

I have tried all suggestions and found my own simple solution.

The problem is that codes written in external environment like C need compiler. Look for its own VS environment, i.e. VS 2008.

Currently my machine runs VS 2012 and faces Unable to find vcvarsall.bat. I studied codes that i want to install to find the VS version. It was VS 2008. i have add to system variable VS90COMNTOOLS as variable name and gave the value of VS120COMNTOOLS.

You can find my step by step solution below:

  1. Right click on My Computer.
  2. Click Properties
  3. Advanced system settings
  4. Environment variables
  5. Add New system variable
  6. Enter VS90COMNTOOLS to the variable name
  7. Enter the value of current version to the new variable.
  8. Close all windows

Now open a new session and pip install your-package

Cannot install packages inside docker Ubuntu image

You need to update the package list in your Ubuntu:

$ sudo apt-get update
$ sudo apt-get install <package_name>

Regex that accepts only numbers (0-9) and NO characters

Your regex ^[0-9] matches anything beginning with a digit, including strings like "1A". To avoid a partial match, append a $ to the end:

^[0-9]*$

This accepts any number of digits, including none. To accept one or more digits, change the * to +. To accept exactly one digit, just remove the *.

UPDATE: You mixed up the arguments to IsMatch. The pattern should be the second argument, not the first:

if (!System.Text.RegularExpressions.Regex.IsMatch(textbox.Text, "^[0-9]*$"))

CAUTION: In JavaScript, \d is equivalent to [0-9], but in .NET, \d by default matches any Unicode decimal digit, including exotic fare like ? (Myanmar 2) and ? (N'Ko 9). Unless your app is prepared to deal with these characters, stick with [0-9] (or supply the RegexOptions.ECMAScript flag).

Python class inherits object

History from Learn Python the Hard Way:

Python's original rendition of a class was broken in many serious ways. By the time this fault was recognized it was already too late, and they had to support it. In order to fix the problem, they needed some "new class" style so that the "old classes" would keep working but you can use the new more correct version.

They decided that they would use a word "object", lowercased, to be the "class" that you inherit from to make a class. It is confusing, but a class inherits from the class named "object" to make a class but it's not an object really its a class, but don't forget to inherit from object.

Also just to let you know what the difference between new-style classes and old-style classes is, it's that new-style classes always inherit from object class or from another class that inherited from object:

class NewStyle(object):
    pass

Another example is:

class AnotherExampleOfNewStyle(NewStyle):
    pass

While an old-style base class looks like this:

class OldStyle():
    pass

And an old-style child class looks like this:

class OldStyleSubclass(OldStyle):
    pass

You can see that an Old Style base class doesn't inherit from any other class, however, Old Style classes can, of course, inherit from one another. Inheriting from object guarantees that certain functionality is available in every Python class. New style classes were introduced in Python 2.2

Show week number with Javascript?

In case you already use jquery-ui (specifically datepicker):

Date.prototype.getWeek = function () { return $.datepicker.iso8601Week(this); }

Usage:

var myDate = new Date();
myDate.getWeek();

More here: UI/Datepicker/iso8601Week

I realize this isn't a general solution as it incurs a dependency. However, considering the popularity of jquery-ui this might just be a simple fit for someone - as it was for me.

How to read a single character from the user?

The answers here were informative, however I also wanted a way to get key presses asynchronously and fire off key presses in separate events, all in a thread-safe, cross-platform way. PyGame was also too bloated for me. So I made the following (in Python 2.7 but I suspect it's easily portable), which I figured I'd share here in case it was useful for anyone else. I stored this in a file named keyPress.py.

class _Getch:
    """Gets a single character from standard input.  Does not echo to the
screen. From http://code.activestate.com/recipes/134892/"""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            try:
                self.impl = _GetchMacCarbon()
            except(AttributeError, ImportError):
                self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys, termios # import termios now or else you'll get the Unix version on the Mac

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()

class _GetchMacCarbon:
    """
    A function which returns the current ASCII key that is down;
    if no ASCII key is down, the null string is returned.  The
    page http://www.mactech.com/macintosh-c/chap02-1.html was
    very helpful in figuring out how to do this.
    """
    def __init__(self):
        import Carbon
        Carbon.Evt #see if it has this (in Unix, it doesn't)

    def __call__(self):
        import Carbon
        if Carbon.Evt.EventAvail(0x0008)[0]==0: # 0x0008 is the keyDownMask
            return ''
        else:
            #
            # The event contains the following info:
            # (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
            #
            # The message (msg) contains the ASCII char which is
            # extracted with the 0x000000FF charCodeMask; this
            # number is converted to an ASCII character with chr() and
            # returned
            #
            (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
            return chr(msg & 0x000000FF)

import threading
            
            
# From  https://stackoverflow.com/a/2022629/2924421
class Event(list):
    def __call__(self, *args, **kwargs):
        for f in self:
            f(*args, **kwargs)

    def __repr__(self):
        return "Event(%s)" % list.__repr__(self)            


def getKey():
    inkey = _Getch()
    import sys
    for i in xrange(sys.maxint):
        k=inkey()
        if k<>'':break
    return k

class KeyCallbackFunction():
    callbackParam = None
    actualFunction = None
    
    def __init__(self, actualFunction, callbackParam):
        self.actualFunction = actualFunction
        self.callbackParam = callbackParam

    def doCallback(self, inputKey):
        if not self.actualFunction is None:
            if self.callbackParam is None:
                callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,))
            else:
                callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,self.callbackParam))
            
            callbackFunctionThread.daemon = True
            callbackFunctionThread.start()
        
        

class KeyCapture():


    gotKeyLock = threading.Lock()
    gotKeys = []
    gotKeyEvent = threading.Event()

    keyBlockingSetKeyLock = threading.Lock()

    addingEventsLock = threading.Lock()
    keyReceiveEvents = Event()


    keysGotLock = threading.Lock()
    keysGot = []

    keyBlockingKeyLockLossy = threading.Lock()
    keyBlockingKeyLossy = None
    keyBlockingEventLossy = threading.Event()
    
    keysBlockingGotLock = threading.Lock()
    keysBlockingGot = []
    keyBlockingGotEvent = threading.Event()
    

    
    wantToStopLock = threading.Lock()
    wantToStop = False
    
    stoppedLock = threading.Lock()
    stopped = True
    
    isRunningEvent = False
    
    getKeyThread = None
    
    keyFunction = None
    keyArgs = None
    
    # Begin capturing keys. A seperate thread is launched that
    # captures key presses, and then these can be received via get,
    # getAsync, and adding an event via addEvent. Note that this
    # will prevent the system to accept keys as normal (say, if
    # you are in a python shell) because it overrides that key
    # capturing behavior.
    
    # If you start capture when it's already been started, a
    # InterruptedError("Keys are still being captured")
    # will be thrown
    
    # Note that get(), getAsync() and events are independent, so if a key is pressed:
    #
    # 1: Any calls to get() that are waiting, with lossy on, will return
    #    that key
    # 2: It will be stored in the queue of get keys, so that get() with lossy
    #    off will return the oldest key pressed not returned by get() yet.
    # 3: All events will be fired with that key as their input
    # 4: It will be stored in the list of getAsync() keys, where that list
    #    will be returned and set to empty list on the next call to getAsync().
    # get() call with it, aand add it to the getAsync() list.
    def startCapture(self, keyFunction=None, args=None):
        # Make sure we aren't already capturing keys
        self.stoppedLock.acquire()
        if not self.stopped:
            self.stoppedLock.release()
            raise InterruptedError("Keys are still being captured")
            return
        self.stopped = False
        self.stoppedLock.release()
        
        # If we have captured before, we need to allow the get() calls to actually
        # wait for key presses now by clearing the event
        if self.keyBlockingEventLossy.is_set():
            self.keyBlockingEventLossy.clear()
            
        # Have one function that we call every time a key is captured, intended for stopping capture
        # as desired
        self.keyFunction = keyFunction
        self.keyArgs = args
        
        # Begin capturing keys (in a seperate thread)
        self.getKeyThread = threading.Thread(target=self._threadProcessKeyPresses)
        self.getKeyThread.daemon = True
        self.getKeyThread.start()
        
        # Process key captures (in a seperate thread)
        self.getKeyThread = threading.Thread(target=self._threadStoreKeyPresses)
        self.getKeyThread.daemon = True
        self.getKeyThread.start()
    
    
    def capturing(self):
        self.stoppedLock.acquire()
        isCapturing = not self.stopped
        self.stoppedLock.release()
        return isCapturing
    # Stops the thread that is capturing keys on the first opporunity
    # has to do so. It usually can't stop immediately because getting a key
    # is a blocking process, so this will probably stop capturing after the
    # next key is pressed.
    #
    # However, Sometimes if you call stopCapture it will stop before starting capturing the
    # next key, due to multithreading race conditions. So if you want to stop capturing
    # reliably, call stopCapture in a function added via addEvent. Then you are
    # guaranteed that capturing will stop immediately after the rest of the callback
    # functions are called (before starting to capture the next key).
    def stopCapture(self):
        self.wantToStopLock.acquire()
        self.wantToStop = True 
        self.wantToStopLock.release()

    # Takes in a function that will be called every time a key is pressed (with that
    # key passed in as the first paramater in that function)
    def addEvent(self, keyPressEventFunction, args=None):   
        self.addingEventsLock.acquire()
        callbackHolder = KeyCallbackFunction(keyPressEventFunction, args)
        self.keyReceiveEvents.append(callbackHolder.doCallback)
        self.addingEventsLock.release()
    def clearEvents(self):
        self.addingEventsLock.acquire()
        self.keyReceiveEvents = Event()
        self.addingEventsLock.release()
    # Gets a key captured by this KeyCapture, blocking until a key is pressed.
    # There is an optional lossy paramater:
    # If True all keys before this call are ignored, and the next pressed key
    #   will be returned.
    # If False this will return the oldest key captured that hasn't
    #   been returned by get yet. False is the default.
    def get(self, lossy=False):
        if lossy:
            # Wait for the next key to be pressed
            self.keyBlockingEventLossy.wait()
            self.keyBlockingKeyLockLossy.acquire()
            keyReceived = self.keyBlockingKeyLossy
            self.keyBlockingKeyLockLossy.release()
            return keyReceived
        else:
            while True:
                # Wait until a key is pressed
                self.keyBlockingGotEvent.wait()
                
                # Get the key pressed
                readKey = None
                self.keysBlockingGotLock.acquire()
                # Get a key if it exists
                if len(self.keysBlockingGot) != 0:
                    readKey = self.keysBlockingGot.pop(0)
                # If we got the last one, tell us to wait
                if len(self.keysBlockingGot) == 0:
                    self.keyBlockingGotEvent.clear()
                self.keysBlockingGotLock.release()
                
                # Process the key (if it actually exists)
                if not readKey is None:
                    return readKey
                
                # Exit if we are stopping
                self.wantToStopLock.acquire()
                if self.wantToStop:
                    self.wantToStopLock.release()
                    return None
                self.wantToStopLock.release()
            
            
            
    
    def clearGetList(self):
        self.keysBlockingGotLock.acquire()
        self.keysBlockingGot = []
        self.keysBlockingGotLock.release()
    
    # Gets a list of all keys pressed since the last call to getAsync, in order
    # from first pressed, second pressed, .., most recent pressed
    def getAsync(self):
        self.keysGotLock.acquire();
        keysPressedList = list(self.keysGot)
        self.keysGot = []
        self.keysGotLock.release()
        return keysPressedList
    
    def clearAsyncList(self):
        self.keysGotLock.acquire();
        self.keysGot = []
        self.keysGotLock.release();

    def _processKey(self, readKey):
        # Append to list for GetKeyAsync
        self.keysGotLock.acquire()
        self.keysGot.append(readKey)
        self.keysGotLock.release()
        
        # Call lossy blocking key events
        self.keyBlockingKeyLockLossy.acquire()
        self.keyBlockingKeyLossy = readKey
        self.keyBlockingEventLossy.set()
        self.keyBlockingEventLossy.clear()
        self.keyBlockingKeyLockLossy.release()
        
        # Call non-lossy blocking key events
        self.keysBlockingGotLock.acquire()
        self.keysBlockingGot.append(readKey)
        if len(self.keysBlockingGot) == 1:
            self.keyBlockingGotEvent.set()
        self.keysBlockingGotLock.release()
        
        # Call events added by AddEvent
        self.addingEventsLock.acquire()
        self.keyReceiveEvents(readKey)
        self.addingEventsLock.release()

    def _threadProcessKeyPresses(self):
        while True:
            # Wait until a key is pressed
            self.gotKeyEvent.wait()
            
            # Get the key pressed
            readKey = None
            self.gotKeyLock.acquire()
            # Get a key if it exists
            if len(self.gotKeys) != 0:
                readKey = self.gotKeys.pop(0)
            # If we got the last one, tell us to wait
            if len(self.gotKeys) == 0:
                self.gotKeyEvent.clear()
            self.gotKeyLock.release()
            
            # Process the key (if it actually exists)
            if not readKey is None:
                self._processKey(readKey)
            
            # Exit if we are stopping
            self.wantToStopLock.acquire()
            if self.wantToStop:
                self.wantToStopLock.release()
                break
            self.wantToStopLock.release()
            
    def _threadStoreKeyPresses(self):
        while True:
            # Get a key
            readKey = getKey()
            
            # Run the potential shut down function
            if not self.keyFunction is None:
                self.keyFunction(readKey, self.keyArgs)
        
            # Add the key to the list of pressed keys
            self.gotKeyLock.acquire()
            self.gotKeys.append(readKey)
            if len(self.gotKeys) == 1:
                self.gotKeyEvent.set()
            self.gotKeyLock.release()
            
            # Exit if we are stopping
            self.wantToStopLock.acquire()
            if self.wantToStop:
                self.wantToStopLock.release()
                self.gotKeyEvent.set()
                break
            self.wantToStopLock.release()
    
        
        # If we have reached here we stopped capturing
        
        # All we need to do to clean up is ensure that
        # all the calls to .get() now return None.
        # To ensure no calls are stuck never returning,
        # we will leave the event set so any tasks waiting
        # for it immediately exit. This will be unset upon
        # starting key capturing again.
        
        self.stoppedLock.acquire()
        
        # We also need to set this to True so we can start up
        # capturing again.
        self.stopped = True
        self.stopped = True
        
        self.keyBlockingKeyLockLossy.acquire()
        self.keyBlockingKeyLossy = None
        self.keyBlockingEventLossy.set()
        self.keyBlockingKeyLockLossy.release()
        
        self.keysBlockingGotLock.acquire()
        self.keyBlockingGotEvent.set()
        self.keysBlockingGotLock.release()
        
        self.stoppedLock.release()

The idea is that you can either simply call keyPress.getKey(), which will read a key from the keyboard, then return it.

If you want something more than that, I made a KeyCapture object. You can create one via something like keys = keyPress.KeyCapture().

Then there are three things you can do:

addEvent(functionName) takes in any function that takes in one parameter. Then every time a key is pressed, this function will be called with that key's string as it's input. These are ran in a separate thread, so you can block all you want in them and it won't mess up the functionality of the KeyCapturer nor delay the other events.

get() returns a key in the same blocking way as before. It is now needed here because the keys are being captured via the KeyCapture object now, so keyPress.getKey() would conflict with that behavior and both of them would miss some keys since only one key can be captured at a time. Also, say the user presses 'a', then 'b', you call get(), the user presses 'c'. That get() call will immediately return 'a', then if you call it again it will return 'b', then 'c'. If you call it again it will block until another key is pressed. This ensures that you don't miss any keys, in a blocking way if desired. So in this way it's a little different than keyPress.getKey() from before

If you want the behavior of getKey() back, get(lossy=True) is like get(), except that it only returns keys pressed after the call to get(). So in the above example, get() would block until the user presses 'c', and then if you call it again it will block until another key is pressed.

getAsync() is a little different. It's designed for something that does a lot of processing, then occasionally comes back and checks which keys were pressed. Thus getAsync() returns a list of all the keys pressed since the last call to getAsync(), in order from oldest key pressed to most recent key pressed. It also doesn't block, meaning that if no keys have been pressed since the last call to getAsync(), an empty [] will be returned.

To actually start capturing keys, you need to call keys.startCapture() with your keys object made above. startCapture is non-blocking, and simply starts one thread that just records the key presses, and another thread to process those key presses. There are two threads to ensure that the thread that records key presses doesn't miss any keys.

If you want to stop capturing keys, you can call keys.stopCapture() and it will stop capturing keys. However, since capturing a key is a blocking operation, the thread capturing keys might capture one more key after calling stopCapture().

To prevent this, you can pass in an optional parameter(s) into startCapture(functionName, args) of a function that just does something like checks if a key equals 'c' and then exits. It's important that this function does very little before, for example, a sleep here will cause us to miss keys.

However, if stopCapture() is called in this function, key captures will be stopped immediately, without trying to capture any more, and that all get() calls will be returned immediately, with None if no keys have been pressed yet.

Also, since get() and getAsync() store all the previous keys pressed (until you retrieve them), you can call clearGetList() and clearAsyncList() to forget the keys previously pressed.

Note that get(), getAsync() and events are independent, so if a key is pressed:

  1. One call to get() that is waiting, with lossy on, will return that key. The other waiting calls (if any) will continue waiting.
  2. That key will be stored in the queue of get keys, so that get() with lossy off will return the oldest key pressed not returned by get() yet.
  3. All events will be fired with that key as their input
  4. That key will be stored in the list of getAsync() keys, where that lis twill be returned and set to empty list on the next call to getAsync()

If all this is too much, here is an example use case:

import keyPress
import time
import threading

def KeyPressed(k, printLock):
    printLock.acquire()
    print "Event: " + k
    printLock.release()
    time.sleep(4)
    printLock.acquire()
    print "Event after delay: " + k
    printLock.release()

def GetKeyBlocking(keys, printLock):    
    while keys.capturing():
        keyReceived = keys.get()
        time.sleep(1)
        printLock.acquire()
        if not keyReceived is None:
            print "Block " + keyReceived
        else:
            print "Block None"
        printLock.release()

def GetKeyBlockingLossy(keys, printLock):   
    while keys.capturing():
        keyReceived = keys.get(lossy=True)
        time.sleep(1)
        printLock.acquire()
        if not keyReceived is None:
            print "Lossy: " + keyReceived
        else:
            print "Lossy: None"
        printLock.release()

def CheckToClose(k, (keys, printLock)):
    printLock.acquire()
    print "Close: " + k
    printLock.release()
    if k == "c":
        keys.stopCapture()
        
printLock = threading.Lock()

print "Press a key:"
print "You pressed: " + keyPress.getKey()
print ""

keys = keyPress.KeyCapture()

keys.addEvent(KeyPressed, printLock)



print "Starting capture"
            
keys.startCapture(CheckToClose, (keys, printLock))
            
getKeyBlockingThread = threading.Thread(target=GetKeyBlocking, args=(keys, printLock))
getKeyBlockingThread.daemon = True
getKeyBlockingThread.start()

            
getKeyBlockingThreadLossy = threading.Thread(target=GetKeyBlockingLossy, args=(keys, printLock))
getKeyBlockingThreadLossy.daemon = True
getKeyBlockingThreadLossy.start()

while keys.capturing():
    keysPressed = keys.getAsync()
    printLock.acquire()
    if keysPressed != []:
        print "Async: " + str(keysPressed)
    printLock.release()
    time.sleep(1)

print "done capturing"

It is working well for me from the simple test I made, but I will happily take others feedback as well if there is something I missed.

I posted this here as well.

Regular Expression Validation For Indian Phone Number and Mobile number

you can implement following regex regex = '^[6-9][0-9]{9}$'

Using subprocess to run Python script on Windows

When you are running a python script on windows in subprocess you should use python in front of the script name. Try:

process = subprocess.Popen("python /the/script.py")

Download a file from HTTPS using download.file()

Offering the curl package as an alternative that I found to be reliable when extracting large files from an online database. In a recent project, I had to download 120 files from an online database and found it to half the transfer times and to be much more reliable than download.file.

#install.packages("curl")
library(curl)
#install.packages("RCurl")
library(RCurl)

ptm <- proc.time()
URL <- "https://d396qusza40orc.cloudfront.net/getdata%2Fdata%2Fss06hid.csv"
x <- getURL(URL)
proc.time() - ptm
ptm

ptm1 <- proc.time()
curl_download(url =URL ,destfile="TEST.CSV",quiet=FALSE, mode="wb")
proc.time() - ptm1
ptm1

ptm2 <- proc.time()
y = download.file(URL, destfile = "./data/data.csv", method="curl")
proc.time() - ptm2
ptm2

In this case, rough timing on your URL showed no consistent difference in transfer times. In my application, using curl_download in a script to select and download 120 files from a website decreased my transfer times from 2000 seconds per file to 1000 seconds and increased the reliability from 50% to 2 failures in 120 files. The script is posted in my answer to a question I asked earlier, see .

How do you plot bar charts in gnuplot?

I recommend Derek Bruening's bar graph generator Perl script. Available at http://www.burningcutlery.com/derek/bargraph/

How to create Gmail filter searching for text only at start of subject line?

Regex is not on the list of search features, and it was on (more or less, as Better message search functionality (i.e. Wildcard and partial word search)) the list of pre-canned feature requests, so the answer is "you cannot do this via the Gmail web UI" :-(

There are no current Labs features which offer this. SIEVE filters would be another way to do this, that too was not supported, there seems to no longer be any definitive statement on SIEVE support in the Gmail help.

Updated for link rot The pre-canned list of feature requests was, er canned, the original is on archive.org dated 2012, now you just get redirected to a dumbed down page telling you how to give feedback. Lack of SIEVE support was covered in answer 78761 Does Gmail support all IMAP features?, since some time in 2015 that answer silently redirects to the answer about IMAP client configuration, archive.org has a copy dated 2014.

With the current search facility brackets of any form () {} [] are used for grouping, they have no observable effect if there's just one term within. Using (aaa|bbb) and [aaa|bbb] are equivalent and will both find words aaa or bbb. Most other punctuation characters, including \, are treated as a space or a word-separator, + - : and " do have special meaning though, see the help.

As of 2016, only the form "{term1 term2}" is documented for this, and is equivalent to the search "term1 OR term2".

You can do regex searches on your mailbox (within limits) programmatically via Google docs: http://www.labnol.org/internet/advanced-gmail-search/21623/ has source showing how it can be done (copy the document, then Tools > Script Editor to get the complete source).

You could also do this via IMAP as described here: Python IMAP search for partial subject and script something to move messages to different folder. The IMAP SEARCH verb only supports substrings, not regex (Gmail search is further limited to complete words, not substrings), further processing of the matches to apply a regex would be needed.

For completeness, one last workaround is: Gmail supports plus addressing, if you can change the destination address to [email protected] it will still be sent to your mailbox where you can filter by recipient address. Make sure to filter using the full email address to:[email protected]. This is of course more or less the same thing as setting up a dedicated Gmail address for this purpose :-)

onMeasure custom view explanation

If you don't need to change something onMeasure - there's absolutely no need for you to override it.

Devunwired code (the selected and most voted answer here) is almost identical to what the SDK implementation already does for you (and I checked - it had done that since 2009).

You can check the onMeasure method here :

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec),
            getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec));
}

public static int getDefaultSize(int size, int measureSpec) {
    int result = size;
    int specMode = MeasureSpec.getMode(measureSpec);
    int specSize = MeasureSpec.getSize(measureSpec);

    switch (specMode) {
    case MeasureSpec.UNSPECIFIED:
        result = size;
        break;
    case MeasureSpec.AT_MOST:
    case MeasureSpec.EXACTLY:
        result = specSize;
        break;
    }
    return result;
}

Overriding SDK code to be replaced with the exact same code makes no sense.

This official doc's piece that claims "the default onMeasure() will always set a size of 100x100" - is wrong.

How can I convert integer into float in Java?

You just need to cast at least one of the operands to a float:

float z = (float) x / y;

or

float z = x / (float) y;

or (unnecessary)

float z = (float) x / (float) y;

Where are static methods and static variables stored in Java?

Static methods (in fact all methods) as well as static variables are stored in the PermGen section of the heap, since they are part of the reflection data (class related data, not instance related).

Update for clarification:

Note that only the variables and their technical values (primitives or references) are stored in PermGen space.

If your static variable is a reference to an object that object itself is stored in the normal sections of the heap (young/old generation or survivor space). Those objects (unless they are internal objects like classes etc.) are not stored in PermGen space.

Example:

static int i = 1; //the value 1 is stored in the PermGen section
static Object o = new SomeObject(); //the reference(pointer/memory address) is stored in the PermGen section, the object itself is not.


A word on garbage collection:

Do not rely on finalize() as it's not guaranteed to run. It is totally up to the JVM to decide when to run the garbage collector and what to collect, even if an object is eligible for garbage collection.

Of course you can set a static variable to null and thus remove the reference to the object on the heap but that doesn't mean the garbage collector will collect it (even if there are no more references).

Additionally finalize() is run only once, so you have to make sure it doesn't throw exceptions or otherwise prevent the object to be collected. If you halt finalization through some exception, finalize() won't be invoked on the same object a second time.

A final note: how code, runtime data etc. are stored depends on the JVM which is used, i.e. HotSpot might do it differently than JRockit and this might even differ between versions of the same JVM. The above is based on HotSpot for Java 5 and 6 (those are basically the same) since at the time of answering I'd say that most people used those JVMs. Due to major changes in the memory model as of Java 8, the statements above might not be true for Java 8 HotSpot - and I didn't check the changes of Java 7 HotSpot, so I guess the above is still true for that version, but I'm not sure here.

'float' vs. 'double' precision

It's not exactly double precision because of how IEEE 754 works, and because binary doesn't really translate well to decimal. Take a look at the standard if you're interested.

How to send email to multiple address using System.Net.Mail

namespace WebForms.Code.Logging {

    public class ObserverLogToEmail: ILog {
        private string from;
        private string to;
        private string subject;
        private string body;
        private SmtpClient smtpClient;
        private MailMessage mailMessage;
        private MailPriority mailPriority;
        private MailAddressCollection mailAddressCollection;
        private MailAddress fromMailAddress, toMailAddress;
        public MailAddressCollection toMailAddressCollection {
            get;
            set;
        }
        public MailAddressCollection ccMailAddressCollection {
            get;
            set;
        }
        public MailAddressCollection bccMailAddressCollection {
            get;
            set;
        }

        public ObserverLogToEmail(string from, string to, string subject, string body, SmtpClient smtpClient) {
            this.from = from;
            this.to = to;
            this.subject = subject;
            this.body = body;

            this.smtpClient = smtpClient;
        }

        public ObserverLogToEmail(MailAddress fromMailAddress, MailAddress toMailAddress,
        string subject, string content, SmtpClient smtpClient) {
            try {
                this.fromMailAddress = fromMailAddress;
                this.toMailAddress = toMailAddress;
                this.subject = subject;
                this.body = content;

                this.smtpClient = smtpClient;

                mailAddressCollection = new MailAddressCollection();

            } catch {
                throw new SmtpException(SmtpStatusCode.CommandNotImplemented);
            }
        }

        public ObserverLogToEmail(MailAddressCollection fromMailAddressCollection,
        MailAddressCollection toMailAddressCollection,
        string subject, string content, SmtpClient smtpClient) {
            try {
                this.toMailAddressCollection = toMailAddressCollection;
                this.ccMailAddressCollection = ccMailAddressCollection;
                this.subject = subject;
                this.body = content;

                this.smtpClient = smtpClient;

            } catch {
                throw new SmtpException(SmtpStatusCode.CommandNotImplemented);
            }
        }

        public ObserverLogToEmail(MailAddressCollection toMailAddressCollection,
        MailAddressCollection ccMailAddressCollection,
        MailAddressCollection bccMailAddressCollection,
        string subject, string content, SmtpClient smtpClient) {
            try {
                this.toMailAddressCollection = toMailAddressCollection;
                this.ccMailAddressCollection = ccMailAddressCollection;
                this.bccMailAddressCollection = bccMailAddressCollection;

                this.subject = subject;
                this.body = content;

                this.smtpClient = smtpClient;

            } catch {
                throw new SmtpException(SmtpStatusCode.CommandNotImplemented);
            }
        }#region ILog Members

        // sends a log request via email.
        // actual email 'Send' calls are commented out.
        // uncomment if you have the proper email privileges.
        public void Log(object sender, LogEventArgs e) {
            string message = "[" + e.Date.ToString() + "] " + e.SeverityString + ": " + e.Message;
            fromMailAddress = new MailAddress("", "HaNN", System.Text.Encoding.UTF8);
            toMailAddress = new MailAddress("", "XXX", System.Text.Encoding.UTF8);

            mailMessage = new MailMessage(fromMailAddress, toMailAddress);
            mailMessage.Subject = subject;
            mailMessage.Body = body;

            // commented out for now. you need privileges to send email.
            // _smtpClient.Send(from, to, subject, body);
            smtpClient.Send(mailMessage);
        }

        public void LogAllEmails(object sender, LogEventArgs e) {
            try {
                string message = "[" + e.Date.ToString() + "] " + e.SeverityString + ": " + e.Message;

                mailMessage = new MailMessage();
                mailMessage.Subject = subject;
                mailMessage.Body = body;

                foreach(MailAddress toMailAddress in toMailAddressCollection) {
                    mailMessage.To.Add(toMailAddress);

                }
                foreach(MailAddress ccMailAddress in ccMailAddressCollection) {
                    mailMessage.CC.Add(ccMailAddress);
                }
                foreach(MailAddress bccMailAddress in bccMailAddressCollection) {
                    mailMessage.Bcc.Add(bccMailAddress);
                }
                if (smtpClient == null) {
                    var smtp = new SmtpClient {
                        Host = "smtp.gmail.com",
                        Port = 587,
                        EnableSsl = true,
                        DeliveryMethod = SmtpDeliveryMethod.Network,
                        Credentials = new NetworkCredential("yourEmailAddress", "yourPassword"),
                        Timeout = 30000
                    };
                } else smtpClient.SendAsync(mailMessage, null);
            } catch (Exception) {

                throw;
            }
        }
    }

Why is Java Vector (and Stack) class considered obsolete or deprecated?

Besides the already stated answers about using Vector, Vector also has a bunch of methods around enumeration and element retrieval which are different than the List interface, and developers (especially those who learned Java before 1.2) can tend to use them if they are in the code. Although Enumerations are faster, they don't check if the collection was modified during iteration, which can cause issues, and given that Vector might be chosen for its syncronization - with the attendant access from multiple threads, this makes it a particularly pernicious problem. Usage of these methods also couples a lot of code to Vector, such that it won't be easy to replace it with a different List implementation.

How to set up Automapper in ASP.NET Core

about theutz answer , there is no need to specify the IMapper mapper parrameter at the controllers constructor.

you can use the Mapper as it is a static member at any place of the code.

public class UserController : Controller {
   public someMethod()
   {
      Mapper.Map<User, UserDto>(user);
   }
}

Advantages of std::for_each over for loop

The for_each loop is meant to hide the iterators (detail of how a loop is implemented) from the user code and define clear semantics on the operation: each element will be iterated exactly once.

The problem with readability in the current standard is that it requires a functor as the last argument instead of a block of code, so in many cases you must write specific functor type for it. That turns into less readable code as functor objects cannot be defined in-place (local classes defined within a function cannot be used as template arguments) and the implementation of the loop must be moved away from the actual loop.

struct myfunctor {
   void operator()( int arg1 ) { code }
};
void apply( std::vector<int> const & v ) {
   // code
   std::for_each( v.begin(), v.end(), myfunctor() );
   // more code
}

Note that if you want to perform an specific operation on each object, you can use std::mem_fn, or boost::bind (std::bind in the next standard), or boost::lambda (lambdas in the next standard) to make it simpler:

void function( int value );
void apply( std::vector<X> const & v ) {
   // code
   std::for_each( v.begin(), v.end(), boost::bind( function, _1 ) );
   // code
}

Which is not less readable and more compact than the hand rolled version if you do have function/method to call in place. The implementation could provide other implementations of the for_each loop (think parallel processing).

The upcoming standard takes care of some of the shortcomings in different ways, it will allow for locally defined classes as arguments to templates:

void apply( std::vector<int> const & v ) {
   // code
   struct myfunctor {
      void operator()( int ) { code }
   };
   std::for_each( v.begin(), v.end(), myfunctor() );
   // code
}

Improving the locality of code: when you browse you see what it is doing right there. As a matter of fact, you don't even need to use the class syntax to define the functor, but use a lambda right there:

void apply( std::vector<int> const & v ) {
   // code
   std::for_each( v.begin(), v.end(), 
      []( int ) { // code } );
   // code
}

Even if for the case of for_each there will be an specific construct that will make it more natural:

void apply( std::vector<int> const & v ) {
   // code
   for ( int i : v ) {
      // code
   }
   // code
}

I tend to mix the for_each construct with hand rolled loops. When only a call to an existing function or method is what I need (for_each( v.begin(), v.end(), boost::bind( &Type::update, _1 ) )) I go for the for_each construct that takes away from the code a lot of boiler plate iterator stuff. When I need something more complex and I cannot implement a functor just a couple of lines above the actual use, I roll my own loop (keeps the operation in place). In non-critical sections of code I might go with BOOST_FOREACH (a co-worker got me into it)

How to downgrade Xcode to previous version?

I'm assuming you are having at least OSX 10.7, so go ahead into the applications folder (Click on Finder icon > On the Sidebar, you'll find "Applications", click on it ), delete the "Xcode" icon. That will remove Xcode from your system completely. Restart your mac.

Now go to https://developer.apple.com/download/more/ and download an older version of Xcode, as needed and install. You need an Apple ID to login to that portal.

Binding Button click to a method

You have various possibilies. The most simple and the most ugly is:

XAML

<Button Name="cmdCommand" Click="Button_Clicked" Content="Command"/> 

Code Behind

private void Button_Clicked(object sender, RoutedEventArgs e) { 
    FrameworkElement fe=sender as FrameworkElement;
    ((YourClass)fe.DataContext).DoYourCommand();     
} 

Another solution (better) is to provide a ICommand-property on your YourClass. This command will have already a reference to your YourClass-object and therefore can execute an action on this class.

XAML

<Button Name="cmdCommand" Command="{Binding YourICommandReturningProperty}" Content="Command"/>

Because during writing this answer, a lot of other answers were posted, I stop writing more. If you are interested in one of the ways I showed or if you think I have made a mistake, make a comment.

How to position the form in the center screen?

Change this:

public FrameForm() { 
    initComponents(); 
}

to this:

public FrameForm() {
    initComponents();
    this.setLocationRelativeTo(null);
}

How do I render a Word document (.doc, .docx) in the browser using JavaScript?

If you wanted to pre-process your DOCX files, rather than waiting until runtime you could convert them into HTML first by using a file conversion API such as Zamzar. You could use the API to programatically convert from DOCX to HMTL, save the output to your server and then serve that HTML up to your end users.

Conversion is pretty easy:

curl https://api.zamzar.com/v1/jobs \
-u API_KEY: \
-X POST \
-F "[email protected]" \
-F "target_format=html5"

This would remove any runtime dependencies on Google & Microsoft's services (for example if they were down, or you were rate limited by them).

It also has the benefit that you could extend to other filetypes if you wanted (PPTX, XLS, DOC etc)

Online PHP syntax checker / validator

In case you're interested, an offline checker that does complicated type analysis: http://strongphp.org It is not online however.

Applying an ellipsis to multiline text

I have just been playing around a little bit with this concept. Basically, if you are ok with potentially having a pixel or so cut off from your last character, here is a pure css and html solution:

The way this works is by absolutely positioning a div below the viewable region of a viewport. We want the div to offset up into the visible region as our content grows. If the content grows too much, our div will offset too high, so upper bound the height our content can grow.

HTML:

<div class="text-container">
  <span class="text-content">
    PUT YOUR TEXT HERE
    <div class="ellipsis">...</div> // You could even make this a pseudo-element
  </span>
</div>

CSS:

.text-container {
    position: relative;
    display: block;
    color: #838485;
    width: 24em;
    height: calc(2em + 5px); // This is the max height you want to show of the text. A little extra space is for characters that extend below the line like 'j'
    overflow: hidden;
    white-space: normal;
}

.text-content {
  word-break: break-all;
  position: relative;
  display: block;
  max-height: 3em;       // This prevents the ellipsis element from being offset too much. It should be 1 line height greater than the viewport 
}

.ellipsis {
  position: absolute;
  right: 0;
  top: calc(4em + 2px - 100%); // Offset grows inversely with content height. Initially extends below the viewport, as content grows it offsets up, and reaches a maximum due to max-height of the content
  text-align: left;
  background: white;
}

I have tested this in Chrome, FF, Safari, and IE 11.

You can check it out here: http://codepen.io/puopg/pen/vKWJwK

You might even be able to alleviate the abrupt cut off of the character with some CSS magic.

EDIT: I guess one thing that this imposes is word-break: break-all since otherwise the content would not extend to the very end of the viewport. :(

Could not load file or assembly for Oracle.DataAccess in .NET

I'm going to give you the answers from what I've just went through on Windows Server 2008 R2 which is a 64 bit operating system. The application suite of libraries I was given were developed using .net 3.5 x86 with the older DLL libraries and I was stuck because I had installed the newer x64 clients from oracle.

What I found was the following: Install the latest x64 client from Oracle for Windows Server 2008. I believe this would be the 2.7.0 client. When you select the installation, make sure you do custom and select the .NET libraries. Configure your tnsnames files and test your tnsping against your data source.

Next, if you are running a 32 bit application, install the same version of the client for 32 bit. Also, follow the same installation routine, and select the same home.

When your finished, you will find that you have a single app/product with two client directories (Client1 and Client2).

If you navigate to the windows/assemblies directory you will find that you have a reference to the Oracle.DataAccess.dll (x2) with one for x86 and one for AMD64.

Now, depending on if you have developers or are developing on the machine yourself, you may be ok here, however, if they are using older drivers, then you need to perform one last step.

Navigate to the app\name\product\version\client_1\odp.net\publisher policy\2.x directory. Included in here are two policy files. use gacutil /i to install the Policy.2.111.Oracle.DataAccess.dll into the GAC. This will redirect legacy oracle ODP calls to the newer versions. So, if someone developed with the 10g client, it will now work with the 11 client.

FYI -- Some may be installing the latest ODP.NET with the 2.111.7.20. The main oracle client itself comes with 2.111.7.0 .. I've not had any success with the 7.20 but have no issues with the 7.0 client.

Why does "pip install" inside Python raise a SyntaxError?

If you are doing it from command line,

try -

python -m pip install selenium

or (for Python3 and above)

python3 -m pip install selenium

How can I know if Object is String type object?

From JDK 14+ which includes JEP 305 we can do Pattern Matching for instanceof

Patterns basically test that a value has a certain type, and can extract information from the value when it has the matching type.

Before Java 14

if (obj instanceof String) {
    String str = (String) obj; // need to declare and cast again the object
    .. str.contains(..) ..
}else{
     str = ....
}

Java 14 enhancements

if (!(obj instanceof String str)) {
    .. str.contains(..) .. // no need to declare str object again with casting
} else {
    .. str....
}

We can also combine the type check and other conditions together

if (obj instanceof String str && str.length() > 4) {.. str.contains(..) ..}

The use of pattern matching in instanceof should reduce the overall number of explicit casts in Java programs.

PS: instanceOf will only match when the object is not null, then only it can be assigned to str.

Remove the last three characters from a string

str= str.Remove(str.Length - 3);

How to List All Redis Databases?

Or you can just run the following command and you will see all databases of the Redis instance without firing up redis-cli:

$ redis-cli INFO | grep ^db
db0:keys=1500,expires=2
db1:keys=200000,expires=1
db2:keys=350003,expires=1

Conditionally change img src based on model data

Another alternative (other than binary operators suggested by @jm-) is to use ng-switch:

<span ng-switch on="interface">
   <img ng-switch-when="UP" src='green-checkmark.png'>
   <img ng-switch-default   src='big-black-X.png'>
</span>

ng-switch will likely be better/easier if you have more than two images.

How to view hierarchical package structure in Eclipse package explorer

For Eclipse in Macbook it is just 2 click process:

  • Click on view menu (3 dot symbol) in package explorer -> hover over package presentation -> Click on Hierarchical

enter image description here

How to send email from localhost WAMP Server to send email Gmail Hotmail or so forth?

Configuring a working email client from localhost is quite a chore, I have spent hours of frustration attempting it. At last I have found this way to send mails (using WAMP, XAMPP, etc.):

Install hMailServer

Configure this hMailServer setting:

  1. Open hMailServer Administrator.
  2. Click the "Add domain ..." button to create a new domain.
  3. Under the domain text field, enter your computer's localhost IP.
    • Example: 127.0.0.1 is your localhost IP.
  4. Click the "Save" button.
  5. Now go to Settings > Protocols > SMTP and select the "Delivery of Email" tab.
  6. Find the localhost field enter "localhost".
  7. Click the Save button.

Configure your Gmail account, perform following modification:

  1. Go to Settings > Protocols > SMTP and select "Delivery of Email" tab.
  2. Enter "smtp.gmail.com" in the Remote Host name field.
  3. Enter "465" as the port number.
  4. Check "Server requires authentication".
  5. Enter your Google Mail address in the Username field.
  6. Enter your Google Mail password in the password field.
  7. Check mark "Use SSL"
  8. Save all changes.

Optional

If you want to send email from another computer you need to allow deliveries from External to External accounts by following steps:

  1. Go to Settings > Advanced > IP Ranges and double click on "My Computer" which should have IP address of 127.0.0.1
  2. Check the Allow Deliveries from External to External accounts Checkbox.
  3. Save settings using Save button.

Flutter : Vertically center column

CrossAlignment.center is using the Width of the 'Child Widget' to center itself and hence gets rendered at the start of the page.

When the Column is centered within the page body's 'Center Container' , the CrossAlignment.center uses page body's 'Center' as reference and renders the widget at the center of the page

enter image description here

Code

import 'package:flutter/material.dart';

void main() => runApp(MaterialApp(
    title:"DynamicWidgetApp",
    home:DynamicWidgetApp(),

));

class DynamicWidgetApp extends StatefulWidget{
  @override
  DynamicWidgetAppState createState() => DynamicWidgetAppState();
  }

class  DynamicWidgetAppState extends State<DynamicWidgetApp>{
  @override
  Widget build(BuildContext context) {

    return Scaffold(
      body: Center(
     //Removing body:Center will change the reference
    // and render the widget at the start of the page 
        child: Column(
            mainAxisAlignment : MainAxisAlignment.center,
            crossAxisAlignment : CrossAxisAlignment.center,
            children: [
              Text("My Centered Widget"),
            ]
          ),
      ),
      floatingActionButton: FloatingActionButton(
        // onPressed: ,
        child : Icon(Icons.add),
      ),
      );
    }
  }

How can I tell if I'm running in 64-bit JVM or 32-bit JVM (from within a program)?

If you're using JNA, you can do thisPlatform.is64Bit().

Converting ArrayList to HashMap

The general methodology would be to iterate through the ArrayList, and insert the values into the HashMap. An example is as follows:

HashMap<String, Product> productMap = new HashMap<String, Product>();
for (Product product : productList) {
   productMap.put(product.getProductCode(), product);
}

How to export a table dataframe in PySpark to csv?

How about this (in you don't want an one liner) ?

for row in df.collect():
    d = row.asDict()
    s = "%d\t%s\t%s\n" % (d["int_column"], d["string_column"], d["string_column"])
    f.write(s)

f is a opened file descriptor. Also the separator is a TAB char, but it's easy to change to whatever you want.

NoClassDefFoundError while trying to run my jar with java.exe -jar...what's wrong?

This is the problem that is occurring,

if the JAR file was loaded from "C:\java\apps\appli.jar", and your manifest file has the Class-Path: reference "lib/other.jar", the class loader will look in "C:\java\apps\lib\" for "other.jar". It won't look at the JAR file entry "lib/other.jar".

Solution:-

  1. Right click on project, Select Export.
  2. Select Java Folder and in it select Runnable JAR File instead of JAR file.
  3. Select the proper options and in the Library Handling section select the 3rd option i.e. (Copy required libraries into a sub-folder next to the generated JAR).

[ EDIT = 3rd option generates a folder in addition to the jar, 2nd option ("Package required libraries into generated JAR") can also be used as you have the jar. ]

  1. Click finish and your JAR is created at the specified position along with a folder that contains the JARS mentioned in the manifest file.
  2. open the terminal,give the proper path to your jar and run it using this command java -jar abc.jar

    Now what will happen is the class loader will look in the correct folder for the referenced JARS since now they are present in the same folder that contains your app JAR..There is no "java.lang.NoClassDefFoundError" exception thrown now.

This worked for me... Hope it works for you too!!!

Angular2 - Http POST request parameters

Update for Angualar 4.3+

Now we can use HttpClient instead of Http

Guide is here

Sample code

const myheader = new HttpHeaders().set('Content-Type', 'application/x-www-form-urlencoded')
let body = new HttpParams();
body = body.set('username', USERNAME);
body = body.set('password', PASSWORD);
http
  .post('/api', body, {
    headers: myheader),
  })
  .subscribe();

Deprecated

Or you can do like this:

let urlSearchParams = new URLSearchParams();
urlSearchParams.append('username', username);
urlSearchParams.append('password', password);
let body = urlSearchParams.toString()

Update Oct/2017

From angular4+, we don't need headers, or .toString() stuffs. Instead, you can do like below example

import { URLSearchParams } from '@angular/http';

POST/PUT method

let urlSearchParams = new URLSearchParams();
urlSearchParams.append('username', username);
urlSearchParams.append('password', password);
this.http.post('/api', urlSearchParams).subscribe(
      data => {
        alert('ok');
      },
      error => {
        console.log(JSON.stringify(error.json()));
      }
    )

GET/DELETE method

    let urlSearchParams = new URLSearchParams();
    urlSearchParams.append('username', username);
    urlSearchParams.append('password', password);
    this.http.get('/api', { search: urlSearchParams }).subscribe(
      data => {
        alert('ok');
      },
      error => {
        console.log(JSON.stringify(error.json()));
      }
    )

For JSON application/json Content-Type

this.http.post('/api',
      JSON.stringify({
        username: username,
        password: password,
      })).subscribe(
      data => {
        alert('ok');
      },
      error => {
        console.log(JSON.stringify(error.json()));
      }
      )

All inclusive Charset to avoid "java.nio.charset.MalformedInputException: Input length = 1"?

ISO_8859_1 Worked for me! I was reading text file with comma separated values

Initialising an array of fixed size in python

The best bet is to use the numpy library.

from numpy import ndarray

a = ndarray((5,),int)

How to delete all instances of a character in a string in python?

replace() method will work for this. Here is the code that will help to remove character from string. lets say

j_word = 'Stringtoremove'
word = 'String'    

for letter in word:
    if j_word.find(letter) == -1:
        continue
    else:
       # remove matched character
       j_word = j_word.replace(letter, '', 1)

#Output
j_word = "toremove"

Amazon Interview Question: Design an OO parking lot

you would need a parking lot, that holds a multi-dimensional array (specified in the constructor) of a type "space". The parking lot can keep track of how many spaces are taken via calls to functions that fill and empty spaces.Space can hold an enumerated type that tells what kind of space it is. Space also has a method taken(). for the valet parking, just find the first space thats open and put the car there. You will also need a Car object to put in the space, that holds whether it is a handicapped, compact, or regular vehicle.


class ParkingLot
{
    Space[][] spaces;

    ParkingLot(wide, long); // constructor

    FindOpenSpace(TypeOfCar); // find first open space where type matches
}

enum TypeOfSpace = {compact, handicapped, regular };
enum TypeOfCar = {compact, handicapped, regular };

class Space
{
    TypeOfSpace type;
    bool empty;
    // gets and sets here
    // make sure car type
}

class car
{
    TypeOfCar type;
}

Python: convert string to byte array

This works for me (Python 2)

s = "ABCD"
b = bytearray(s)

# if you print whole b, it still displays it as if its original string
print b

# but print first item from the array to see byte value
print b[0]

Reference: http://www.dotnetperls.com/bytes-python

Typescript: Type X is missing the following properties from type Y length, pop, push, concat, and 26 more. [2740]

For those newbies like me, don't assign variable to service response, meaning do

export class ShopComponent implements OnInit {
  public productsArray: Product[];

  ngOnInit() {
      this.productService.getProducts().subscribe(res => {
        this.productsArray = res;
      });
  }
}

Instead of

export class ShopComponent implements OnInit {
    public productsArray: Product[];

    ngOnInit() {
        this.productsArray = this.productService.getProducts().subscribe();
    }
}

Disable webkit's spin buttons on input type="number"?

Not sure if this is the best way to do it, but this makes the spinners disappear on Chrome 8.0.552.5 dev:

input[type=number]::-webkit-inner-spin-button {
    -webkit-appearance: none;
}

jQuery posting JSON

In case you are sending this post request to a cross domain, you should check out this link.

https://stackoverflow.com/a/1320708/969984

Your server is not accepting the cross site post request. So the server configuration needs to be changed to allow cross site requests.

How to convert list of numpy arrays into single numpy array?

I checked some of the methods for speed performance and find that there is no difference! The only difference is that using some methods you must carefully check dimension.

Timing:

|------------|----------------|-------------------|
|            | shape (10000)  |  shape (1,10000)  |
|------------|----------------|-------------------|
| np.concat  |    0.18280     |      0.17960      |
|------------|----------------|-------------------|
|  np.stack  |    0.21501     |      0.16465      |
|------------|----------------|-------------------|
| np.vstack  |    0.21501     |      0.17181      |
|------------|----------------|-------------------|
|  np.array  |    0.21656     |      0.16833      |
|------------|----------------|-------------------|

As you can see I tried 2 experiments - using np.random.rand(10000) and np.random.rand(1, 10000) And if we use 2d arrays than np.stack and np.array create additional dimension - result.shape is (1,10000,10000) and (10000,1,10000) so they need additional actions to avoid this.

Code:

from time import perf_counter
from tqdm import tqdm_notebook
import numpy as np
l = []
for i in tqdm_notebook(range(10000)):
    new_np = np.random.rand(10000)
    l.append(new_np)



start = perf_counter()
stack = np.stack(l, axis=0 )
print(f'np.stack: {perf_counter() - start:.5f}')

start = perf_counter()
vstack = np.vstack(l)
print(f'np.vstack: {perf_counter() - start:.5f}')

start = perf_counter()
wrap = np.array(l)
print(f'np.array: {perf_counter() - start:.5f}')

start = perf_counter()
l = [el.reshape(1,-1) for el in l]
conc = np.concatenate(l, axis=0 )
print(f'np.concatenate: {perf_counter() - start:.5f}')

Parse JSON file using GSON

I'm using gson 2.2.3

public class Main {

/**
 * @param args
 * @throws IOException 
 */
public static void main(String[] args) throws IOException {

    JsonReader jsonReader = new JsonReader(new FileReader("jsonFile.json"));

    jsonReader.beginObject();

    while (jsonReader.hasNext()) {

    String name = jsonReader.nextName();
        if (name.equals("descriptor")) {
             readApp(jsonReader);

        }
    }

   jsonReader.endObject();
   jsonReader.close();

}

public static void readApp(JsonReader jsonReader) throws IOException{
    jsonReader.beginObject();
     while (jsonReader.hasNext()) {
         String name = jsonReader.nextName();
         System.out.println(name);
         if (name.contains("app")){
             jsonReader.beginObject();
             while (jsonReader.hasNext()) {
                 String n = jsonReader.nextName();
                 if (n.equals("name")){
                     System.out.println(jsonReader.nextString());
                 }
                 if (n.equals("age")){
                     System.out.println(jsonReader.nextInt());
                 }
                 if (n.equals("messages")){
                     jsonReader.beginArray();
                     while  (jsonReader.hasNext()) {
                          System.out.println(jsonReader.nextString());
                     }
                     jsonReader.endArray();
                 }
             }
             jsonReader.endObject();
         }

     }
     jsonReader.endObject();
}
}

Where is the Java SDK folder in my computer? Ubuntu 12.04

For me, on Ubuntu, the various versions of JDK were in /usr/lib/jvm.

Checking if a double (or float) is NaN in C++

First solution: if you are using C++11

Since this was asked there were a bit of new developments: it is important to know that std::isnan() is part of C++11

Synopsis

Defined in header <cmath>

bool isnan( float arg ); (since C++11)
bool isnan( double arg ); (since C++11)
bool isnan( long double arg ); (since C++11)

Determines if the given floating point number arg is not-a-number (NaN).

Parameters

arg: floating point value

Return value

true if arg is NaN, false otherwise

Reference

http://en.cppreference.com/w/cpp/numeric/math/isnan

Please note that this is incompatible with -fast-math if you use g++, see below for other suggestions.


Other solutions: if you using non C++11 compliant tools

For C99, in C, this is implemented as a macro isnan(c)that returns an int value. The type of x shall be float, double or long double.

Various vendors may or may not include or not a function isnan().

The supposedly portable way to check for NaN is to use the IEEE 754 property that NaN is not equal to itself: i.e. x == x will be false for x being NaN.

However the last option may not work with every compiler and some settings (particularly optimisation settings), so in last resort, you can always check the bit pattern ...

error_reporting(E_ALL) does not produce error

In your php.ini file check for display_errors. I think it is off.

<?php
error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);

textarea character limit

I found a good solution that uses the maxlength attribute if the browser supports it, and falls back to an unobtrusive javascript pollyfill in unsupporting browsers.

Thanks to @Dan Tello's comment I fixed it up so it works in IE7+ as well:

HTML:

<textarea maxlength="50" id="text">This textarea has a character limit of 50.</textarea>

Javascript:

function maxLength(el) {    
    if (!('maxLength' in el)) {
        var max = el.attributes.maxLength.value;
        el.onkeypress = function () {
            if (this.value.length >= max) return false;
        };
    }
}

maxLength(document.getElementById("text"));

Demo

There is no such thing as a minlength attribute in HTML5.
For the following input types: number, range, date, datetime, datetime-local, month, time, and week (which aren't fully supported yet) use the min and max attributes.

Parse date string and change format

convert string to datetime object

from datetime import datetime
s = "2016-03-26T09:25:55.000Z"
f = "%Y-%m-%dT%H:%M:%S.%fZ"
out = datetime.strptime(s, f)
print(out)
output:
2016-03-26 09:25:55

C++ - unable to start correctly (0xc0150002)

I met such problem. Visual Studio 2008 clearly said: problem was caused by libtiff.dll. It cannot be loaded for some reasom, caused by its manifest (as a matter of fact, this dll has no manifest at all). I fixed it, when I had removed libtiff.dll from my project (but simultaneously I lost ability to open compressed TIFFs!). I recompiled aforementioned dll, but problem still remains. Interesting, that at my own machine I have no such error. Three others comps refused to load my prog. Attention!!! Here http://www.error-repair-tools.com/ppc/error.php?t=0xc0150002 one wise boy wrote, that this error was caused by problem with registry and offers repair tool. I have a solid guess, that this "repair tool" will install some malicious soft at your comp.

How to align linearlayout to vertical center?

use android:layout_gravity instead of android:gravity

android:gravity sets the gravity of the content of the View its used on. android:layout_gravity sets the gravity of the View or Layout in its parent.

Java: Calling a super method which calls an overridden method

During my research for a similar case, I have been ending up by checking the stack trace in the subclass method to find out from where the call is coming from. There are probably smarter ways to do so, but it works out for me and it's a dynamic approach.

public void method2(){
        Exception ex=new Exception();
        StackTraceElement[] ste=ex.getStackTrace();
        if(ste[1].getClassName().equals(this.getClass().getSuperclass().getName())){
            super.method2();
        }
        else{
            //subclass method2 code
        }
}

I think the question to have a solution for the case is reasonable. There are of course ways to solve the issue with different method names or even different parameter types, like already mentioned in the thread, but in my case I dindn't like to confuse by different method names.

Move / Copy File Operations in Java

Here's how to do this with java.nio operations:

public static void copyFile(File sourceFile, File destFile) throws IOException {
    if(!destFile.exists()) {
        destFile.createNewFile();
    }

    FileChannel source = null;
    FileChannel destination = null;
    try {
        source = new FileInputStream(sourceFile).getChannel();
        destination = new FileOutputStream(destFile).getChannel();

        // previous code: destination.transferFrom(source, 0, source.size());
        // to avoid infinite loops, should be:
        long count = 0;
        long size = source.size();              
        while((count += destination.transferFrom(source, count, size-count))<size);
    }
    finally {
        if(source != null) {
            source.close();
        }
        if(destination != null) {
            destination.close();
        }
    }
}

How do you set EditText to only accept numeric values in Android?

For example:

<EditText
android:id="@+id/myNumber"
android:digits="0123456789."
android:inputType="numberDecimal"
/>

How to check for empty value in Javascript?

First, I would check what i gets initialized to, to see if the elements returned by getElementsByName are what you think they are. Maybe split the problem by trying it with a hard-coded name like timetemp0, without the concatenation. You can also run the code through a browser debugger (FireBug, Chrome Dev Tools, IE Dev Tools).

Also, for your if-condition, this should suffice:

if (!timetemp[0].value) {
    // The value is empty.
}
else {
    // The value is not empty.
}

The empty string in Javascript is a falsey value, so the logical negation of that will get you into the if-block.

Laravel: Using try...catch with DB::transaction()

If you use PHP7, use Throwable in catch for catching user exceptions and fatal errors.

For example:

DB::beginTransaction();

try {
    DB::insert(...);    
    DB::commit();
} catch (\Throwable $e) {
    DB::rollback();
    throw $e;
}

If your code must be compartable with PHP5, use Exception and Throwable:

DB::beginTransaction();

try {
    DB::insert(...);    
    DB::commit();
} catch (\Exception $e) {
    DB::rollback();
    throw $e;
} catch (\Throwable $e) {
    DB::rollback();
    throw $e;
}

pip install from git repo branch

For windows & pycharm setup:

If you are using pycharm and If you want to use pip3 install git+https://github.com/...

  • firstly, you should download git from https://git-scm.com/downloads
  • then restart pycharm
  • and you can use pycharm terminal to install what you want

enter image description here

Test for multiple cases in a switch, like an OR (||)

You need to make two case labels.

Control will fall through from the first label to the second, so they'll both execute the same code.

How to reload .bash_profile from the command line?

  1. Save .bash_profile file
  2. Goto user's home directory by typing cd
  3. Reload the profile with . .bash_profile

CSS class for pointer cursor

Bootstrap 3 - Just adding the "btn" Class worked for me.

Without pointer cursor:

<span class="label label-success">text</span>

With pointer cursor:

<span class="label label-success btn">text</span>

How can I represent an 'Enum' in Python?

Here is a nice Python recipe that I found here: http://code.activestate.com/recipes/577024-yet-another-enum-for-python/

def enum(typename, field_names):
    "Create a new enumeration type"

    if isinstance(field_names, str):
        field_names = field_names.replace(',', ' ').split()
    d = dict((reversed(nv) for nv in enumerate(field_names)), __slots__ = ())
    return type(typename, (object,), d)()

Example Usage:

STATE = enum('STATE', 'GET_QUIZ, GET_VERSE, TEACH')

More details can be found on the recipe page.

Insert line after first match using sed

Note the standard sed syntax (as in POSIX, so supported by all conforming sed implementations around (GNU, OS/X, BSD, Solaris...)):

sed '/CLIENTSCRIPT=/a\
CLIENTSCRIPT2="hello"' file

Or on one line:

sed -e '/CLIENTSCRIPT=/a\' -e 'CLIENTSCRIPT2="hello"' file

(-expressions (and the contents of -files) are joined with newlines to make up the sed script sed interprets).

The -i option for in-place editing is also a GNU extension, some other implementations (like FreeBSD's) support -i '' for that.

Alternatively, for portability, you can use perl instead:

perl -pi -e '$_ .= qq(CLIENTSCRIPT2="hello"\n) if /CLIENTSCRIPT=/' file

Or you could use ed or ex:

printf '%s\n' /CLIENTSCRIPT=/a 'CLIENTSCRIPT2="hello"' . w q | ex -s file

What is @ModelAttribute in Spring MVC?

@ModelAttribute simply binds the value from jsp fields to Pojo calss to perform our logic in controller class. If you are familiar with struts, then this is like populating the formbean object upon submission.

How can I sort a dictionary by key?

from operator import itemgetter
# if you would like to play with multiple dictionaries then here you go:
# Three dictionaries that are composed of first name and last name.
user = [
    {'fname': 'Mo', 'lname': 'Mahjoub'},
    {'fname': 'Abdo', 'lname': 'Al-hebashi'},
    {'fname': 'Ali', 'lname': 'Muhammad'}
]
#  This loop will sort by the first and the last names.
# notice that in a dictionary order doesn't matter. So it could put the first name first or the last name first. 
for k in sorted (user, key=itemgetter ('fname', 'lname')):
    print (k)

# This one will sort by the first name only.
for x in sorted (user, key=itemgetter ('fname')):
    print (x)

How to convert PDF files to images

There is a free nuget package (Pdf2Image), which allows the extraction of pdf pages to jpg files or to a collection of images (List ) in just one line

        string file = "c:\\tmp\\test.pdf";

        List<System.Drawing.Image> images = PdfSplitter.GetImages(file, PdfSplitter.Scale.High);

        PdfSplitter.WriteImages(file, "c:\\tmp", PdfSplitter.Scale.High, PdfSplitter.CompressionLevel.Medium);

All source is also available on github Pdf2Image

Jquery: Find Text and replace

More specific:

$("#id1 p:contains('dog')").text($("#id1 p:contains('dog')").text().replace('dog', 'doll'));

/exclude in xcopy just for a file type

For excluding multiple file types, you can use '+' to concatenate other lists. For example:

xcopy /r /d /i /s /y /exclude:excludedfileslist1.txt+excludedfileslist2.txt C:\dev\apan C:\web\apan

Source: http://www.tech-recipes.com/rx/2682/xcopy_command_using_the_exclude_flag/

sorting a List of Map<String, String>

try {
        java.util.Collections.sort(data,
                new Comparator<Map<String, String>>() {
                    SimpleDateFormat sdf = new SimpleDateFormat(
                            "MM/dd/yyyy");

                    public int compare(final Map<String, String> map1,
                            final Map<String, String> map2) {
                        Date date1 = null, date2 = null;
                        try {
                            date1 = sdf.parse(map1.get("Date"));
                            date2 = sdf.parse(map2.get("Date"));
                        } catch (ParseException e) {
                            e.printStackTrace();
                        }
                        if (date1.compareTo(date2) > 0) {
                            return +1;
                        } else if (date1.compareTo(date2) == 0) {
                            return 0;
                        } else {
                            return -1;
                        }
                    }
                });

    } catch (Exception e) {

    }

How to use PrintWriter and File classes in Java?

import java.io.File;
import java.io.PrintWriter;

public class Testing 
{
    public static void main(String[] args) 
    {

        File file = new File("C:/Users/Me/Desktop/directory/file.txt");

        PrintWriter printWriter = null;

        try
        {
            printWriter = new PrintWriter(file);
            printWriter.println("hello");
        }
        catch (FileNotFoundException e)
        {
            e.printStackTrace();
        }
        finally
        {
            if ( printWriter != null ) 
            {
                printWriter.close();
            }
        }
    }
}

Difference between EXISTS and IN in SQL?

Which one is faster depends on the number of queries fetched by the inner query:

  • When your inner query fetching thousand of rows then EXIST would be better choice
  • When your inner query fetching few rows, then IN will be faster

EXIST evaluate on true or false but IN compare multiple value. When you don't know the record is exist or not, your should choose EXIST

How to show the last queries executed on MySQL?

Maybe you could find that out by looking at the query log.

How to pass credentials to httpwebrequest for accessing SharePoint Library

You could also use:

request.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials; 

Setting up an MS-Access DB for multi-user access

Access is a great multi-user database. It has lots of built in features to handle the multi-user situation. In fact, it is so very popular because it is such a great multi-user database. There is an upper limit on how many users can all use the database at the same time doing updates and edits - depending on how knowledgeable the developer is about access and how the database has been designed - anywhere from 20 users to approx 50 users. Some access databases can be built to handle up to 50 concurrent users, while many others can handle 20 or 25 concurrent users updating the database. These figures have been observed for databases that have been in use for several or more years and have been discussed many times on the access newsgroups.

How to sort 2 dimensional array by column value?

in one line:

var cars = [
  {type:"Volvo", year:2016},
  {type:"Saab", year:2001},
  {type:"BMW", year:2010}
]


function myFunction() {
  return cars.sort((a, b)=> a.year - b.year)
}

How to check list A contains any value from list B?

I use this to count:

int cnt = 0;

foreach (var lA in listA)
{
    if (listB.Contains(lA))
    {
        cnt++;
    }
}

Empty set literal?

By all means, please use set() to create an empty set.

But, if you want to impress people, tell them that you can create an empty set using literals and * with Python >= 3.5 (see PEP 448) by doing:

>>> s = {*()}  # or {*{}} or {*[]}
>>> print(s)
set()

this is basically a more condensed way of doing {_ for _ in ()}, but, don't do this.

Populate one dropdown based on selection in another

Setup mine within a closure and with straight JavaScript, explanation provided in comments

_x000D_
_x000D_
(function() {_x000D_
_x000D_
  //setup an object fully of arrays_x000D_
  //alternativly it could be something like_x000D_
  //{"yes":[{value:sweet, text:Sweet}.....]}_x000D_
  //so you could set the label of the option tag something different than the name_x000D_
  var bOptions = {_x000D_
    "yes": ["sweet", "wohoo", "yay"],_x000D_
    "no": ["you suck!", "common son"]_x000D_
  };_x000D_
_x000D_
  var A = document.getElementById('A');_x000D_
  var B = document.getElementById('B');_x000D_
_x000D_
  //on change is a good event for this because you are guarenteed the value is different_x000D_
  A.onchange = function() {_x000D_
    //clear out B_x000D_
    B.length = 0;_x000D_
    //get the selected value from A_x000D_
    var _val = this.options[this.selectedIndex].value;_x000D_
    //loop through bOption at the selected value_x000D_
    for (var i in bOptions[_val]) {_x000D_
      //create option tag_x000D_
      var op = document.createElement('option');_x000D_
      //set its value_x000D_
      op.value = bOptions[_val][i];_x000D_
      //set the display label_x000D_
      op.text = bOptions[_val][i];_x000D_
      //append it to B_x000D_
      B.appendChild(op);_x000D_
    }_x000D_
  };_x000D_
  //fire this to update B on load_x000D_
  A.onchange();_x000D_
_x000D_
})();
_x000D_
<select id='A' name='A'>_x000D_
  <option value='yes' selected='selected'>yes_x000D_
  <option value='no'> no_x000D_
</select>_x000D_
<select id='B' name='B'>_x000D_
</select>
_x000D_
_x000D_
_x000D_

Regular expression to validate US phone numbers?

The easiest way to match both

^\([0-9]{3}\)[0-9]{3}-[0-9]{4}$

and

^[0-9]{3}-[0-9]{3}-[0-9]{4}$

is to use alternation ((...|...)): specify them as two mostly-separate options:

^(\([0-9]{3}\)|[0-9]{3}-)[0-9]{3}-[0-9]{4}$

By the way, when Americans put the area code in parentheses, we actually put a space after that; for example, I'd write (123) 123-1234, not (123)123-1234. So you might want to write:

^(\([0-9]{3}\) |[0-9]{3}-)[0-9]{3}-[0-9]{4}$

(Though it's probably best to explicitly demonstrate the format that you expect phone numbers to be in.)

How to convert image to byte array

Do you only want the pixels or the whole image (including headers) as an byte array?

For pixels: Use the CopyPixels method on Bitmap. Something like:

var bitmap = new BitmapImage(uri);

//Pixel array
byte[] pixels = new byte[width * height * 4]; //account for stride if necessary and whether the image is 32 bit, 16 bit etc.

bitmap.CopyPixels(..size, pixels, fullStride, 0); 

Reset IntelliJ UI to Default

Recent Versions

Window -> Restore Default Layout

(Thanks to Seven4X's answer)

Older Versions

You can simply delete the whole configuration folder ${user.home}/.IntelliJIdea60/config while IntelliJ IDEA is not running. Next time it restarts, everything is restored from the default settings.

It depends on the OS:

https://intellij-support.jetbrains.com/entries/23358108

phpMyAdmin - The MySQL Extension is Missing

In my case I had to install the extension:

yum install php php-mysql httpd

and then restart apache:

service httpd restart

That solved the problem.

How to show/hide JPanels in a JFrame?

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * Style1.java
 *
 * Created on May 5, 2011, 6:31:16 AM
 */
package Test;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;

/**
 *
 * @author Sameera
 */
public class Style2 extends javax.swing.JFrame {

    /** Creates new form Style1 */
    public Style2() {
        initComponents();
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        cmd_SH = new javax.swing.JButton();
        pnl_2 = new javax.swing.JPanel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));

        cmd_SH.setText("Hide");
        cmd_SH.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                cmd_SHActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap(558, Short.MAX_VALUE)
                .addComponent(cmd_SH)
                .addContainerGap())
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap(236, Short.MAX_VALUE)
                .addComponent(cmd_SH)
                .addContainerGap())
        );

        pnl_2.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));

        javax.swing.GroupLayout pnl_2Layout = new javax.swing.GroupLayout(pnl_2);
        pnl_2.setLayout(pnl_2Layout);
        pnl_2Layout.setHorizontalGroup(
            pnl_2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 621, Short.MAX_VALUE)
        );
        pnl_2Layout.setVerticalGroup(
            pnl_2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 270, Short.MAX_VALUE)
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(pnl_2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(pnl_2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(17, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>

    private void cmd_SHActionPerformed(java.awt.event.ActionEvent evt) {                                       


        System.out.println(evt.getActionCommand());
        if (evt.getActionCommand().equals("Hide")) {
            pnl_2.setVisible(false);
            cmd_SH.setText("Show");
            this.setSize(643, 294);
            this.pack();


        }
        if (evt.getActionCommand().equals("Show")) {
            pnl_2.setVisible(true);
            cmd_SH.setText("Hide");
            this.setSize(643, 583);
            this.pack();    
        }
    }                                      

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new Style1().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify
    private javax.swing.JButton cmd_SH;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel pnl_2;
    // End of variables declaration
}

Maven dependency for Servlet 3.0 API?

A convenient way (JBoss recommended) to include Java EE 6 dependencies is demonstrated below. As a result dependencies are placed separately (not all in one jar as in javaee-web-api), source files and javadocs of the libraries are available to download from maven repository.

<properties>
    <jboss.javaee6.spec.version>2.0.0.Final</jboss.javaee6.spec.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.jboss.spec</groupId>
        <artifactId>jboss-javaee-web-6.0</artifactId>
        <version>${jboss.javaee6.spec.version}</version>
        <scope>provided</scope>
        <type>pom</type>
    </dependency>
</dependencies>

To include individual dependencies only, dependencyManagement section and scope import can be used:

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.jboss.spec</groupId>
                <artifactId>jboss-javaee6-specs-bom</artifactId>
                <version>${jboss.javaee6.spec.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <!-- No need specifying version and scope. It is defaulted to version and scope from Bill of Materials (bom) imported pom. -->
        <dependency>
            <groupId>org.jboss.spec.javax.servlet</groupId>
            <artifactId>jboss-servlet-api_3.0_spec</artifactId>
        </dependency>
    </dependencies>

Generate your own Error code in swift 3

I know you have already satisfied with an answer but if you are interested to know the right approach, then this might be helpful for you. I would prefer not to mix http-response error code with the error code in the error object (confused? please continue reading a bit...).

The http response codes are standard error codes about a http response defining generic situations when response is received and varies from 1xx to 5xx ( e.g 200 OK, 408 Request timed out,504 Gateway timeout etc - http://www.restapitutorial.com/httpstatuscodes.html )

The error code in a NSError object provides very specific identification to the kind of error the object describes for a particular domain of application/product/software. For example your application may use 1000 for "Sorry, You can't update this record more than once in a day" or say 1001 for "You need manager role to access this resource"... which are specific to your domain/application logic.

For a very small application, sometimes these two concepts are merged. But they are completely different as you can see and very important & helpful to design and work with large software.

So, there can be two techniques to handle the code in better way:

1. The completion callback will perform all the checks

completionHandler(data, httpResponse, responseError) 

2. Your method decides success and error situation and then invokes corresponding callback

if nil == responseError { 
   successCallback(data)
} else {
   failureCallback(data, responseError) // failure can have data also for standard REST request/response APIs
}

Happy coding :)

Failed to find target with hash string 'android-25'

I got same exception while running gradle build for my android project.

Caused by: java.lang.IllegalStateException: Failed to find target with hash string 'android-27'

This issue related to android SDK version enable for your Android Studio. Please find the solution of this problem from attached screen. enter image description here

Huge performance difference when using group by vs distinct

The two queries express the same question. Apparently the query optimizer chooses two different execution plans. My guess would be that the distinct approach is executed like:

  • Copy all business_key values to a temporary table
  • Sort the temporary table
  • Scan the temporary table, returning each item that is different from the one before it

The group by could be executed like:

  • Scan the full table, storing each value of business key in a hashtable
  • Return the keys of the hashtable

The first method optimizes for memory usage: it would still perform reasonably well when part of the temporary table has to be swapped out. The second method optimizes for speed, but potentially requires a large amount of memory if there are a lot of different keys.

Since you either have enough memory or few different keys, the second method outperforms the first. It's not unusual to see performance differences of 10x or even 100x between two execution plans.

How do I use a file grep comparison inside a bash if/else statement?

Note that, for PIPE being any command or sequence of commands, then:

if PIPE ; then
  # do one thing if PIPE returned with zero status ($?=0)
else 
  # do another thing if PIPE returned with non-zero status ($?!=0), e.g. error
fi 

For the record, [ expr ] is a shell builtin shorthand for test expr.

Since grep returns with status 0 in case of a match, and non-zero status in case of no matches, you can use:

if grep -lq '^MYSQL_ROLE=master' ; then 
  # do one thing 
else 
  # do another thing
fi 

Note the use of -l which only cares about the file having at least one match (so that grep returns as soon as it finds one match, without needlessly continuing to parse the input file.)

on some platforms [ expr ] is not a builtin, but an actual executable /bin/[ (whose last argument will be ]), which is why [ expr ] should contain blanks around the square brackets, and why it must be followed by one of the command list separators (;, &&, ||, |, &, newline)

Use Mockito to mock some methods but not others

Partial mocking of a class is also supported via Spy in mockito

List list = new LinkedList();
List spy = spy(list);

//optionally, you can stub out some methods:
when(spy.size()).thenReturn(100);

//using the spy calls real methods
spy.add("one");
spy.add("two");

//size() method was stubbed - 100 is printed
System.out.println(spy.size());

Check the 1.10.19 and 2.7.22 docs for detailed explanation.

Get Enum from Description attribute

You can't extend Enum as it's a static class. You can only extend instances of a type. With this in mind, you're going to have to create a static method yourself to do this; the following should work when combined with your existing method GetDescription:

public static class EnumHelper
{
    public static T GetEnumFromString<T>(string value)
    {
        if (Enum.IsDefined(typeof(T), value))
        {
            return (T)Enum.Parse(typeof(T), value, true);
        }
        else
        {
            string[] enumNames = Enum.GetNames(typeof(T));
            foreach (string enumName in enumNames)
            {  
                object e = Enum.Parse(typeof(T), enumName);
                if (value == GetDescription((Enum)e))
                {
                    return (T)e;
                }
            }
        }
        throw new ArgumentException("The value '" + value 
            + "' does not match a valid enum name or description.");
    }
}

And the usage of it would be something like this:

Animal giantPanda = EnumHelper.GetEnumFromString<Animal>("Giant Panda");

iOS: Modal ViewController with transparent background

I added these three lines in the init method in the presented view controller, and works like a charm:

self.providesPresentationContextTransitionStyle = YES;
self.definesPresentationContext = YES;
[self setModalPresentationStyle:UIModalPresentationOverCurrentContext];

EDIT (working on iOS 9.3):

self.modalPresentationStyle = UIModalPresentationOverFullScreen;

As per documentation:

UIModalPresentationOverFullScreen A view presentation style in which the presented view covers the screen. The views beneath the presented content are not removed from the view hierarchy when the presentation finishes. So if the presented view controller does not fill the screen with opaque content, the underlying content shows through.

Available in iOS 8.0 and later.

Determine if a String is an Integer in Java

You can use Integer.parseInt() or Integer.valueOf() to get the integer from the string, and catch the exception if it is not a parsable int. You want to be sure to catch the NumberFormatException it can throw.

It may be helpful to note that valueOf() will return an Integer object, not the primitive int.

How can I use jQuery in Greasemonkey?

You might get Component unavailable if you import the jQuery script directly.

Maybe it's what @Conley was talking about...

You can use

@require        http://userscripts.org/scripts/source/85365.user.js

which is an modified version to work on Greasemonkey, and then get the jQuery object

var $ = unsafeWindow.jQuery;
$("div").css("display", "none");

Group by in LINQ

I have created a working code sample with Query Syntax and Method Syntax. I hope it helps the others :)

You can also run the code on .Net Fiddle here:

using System;
using System.Linq;
using System.Collections.Generic;

class Person
{ 
    public int PersonId; 
    public string car  ; 
}

class Result
{ 
   public int PersonId;
   public List<string> Cars; 
}

public class Program
{
    public static void Main()
    {
        List<Person> persons = new List<Person>()
        {
            new Person { PersonId = 1, car = "Ferrari" },
            new Person { PersonId = 1, car = "BMW" },
            new Person { PersonId = 2, car = "Audi"}
        };

        //With Query Syntax

        List<Result> results1 = (
            from p in persons
            group p by p.PersonId into g
            select new Result()
                {
                    PersonId = g.Key, 
                    Cars = g.Select(c => c.car).ToList()
                }
            ).ToList();

        foreach (Result item in results1)
        {
            Console.WriteLine(item.PersonId);
            foreach(string car in item.Cars)
            {
                Console.WriteLine(car);
            }
        }

        Console.WriteLine("-----------");

        //Method Syntax

        List<Result> results2 = persons
            .GroupBy(p => p.PersonId, 
                     (k, c) => new Result()
                             {
                                 PersonId = k,
                                 Cars = c.Select(cs => cs.car).ToList()
                             }
                    ).ToList();

        foreach (Result item in results2)
        {
            Console.WriteLine(item.PersonId);
            foreach(string car in item.Cars)
            {
                Console.WriteLine(car);
            }
        }
    }
}

Here is the result:

1
Ferrari
BMW
2
Audi
-----------
1
Ferrari
BMW
2
Audi