Programs & Examples On #Internet radio

In basic terms, internet radio is an audio service which is broadcast over the internet, rather than by 'traditional' wireless means.

Android sample bluetooth code to send a simple string via bluetooth

I made the following code so that even beginners can understand. Just copy the code and read comments. Note that message to be send is declared as a global variable which you can change just before sending the message. General changes can be done in Handler function.

multiplayerConnect.java

import android.annotation.SuppressLint;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;

public class multiplayerConnect extends AppCompatActivity {

public static final int REQUEST_ENABLE_BT=1;
ListView lv_paired_devices;
Set<BluetoothDevice> set_pairedDevices;
ArrayAdapter adapter_paired_devices;
BluetoothAdapter bluetoothAdapter;
public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
public static final int MESSAGE_READ=0;
public static final int MESSAGE_WRITE=1;
public static final int CONNECTING=2;
public static final int CONNECTED=3;
public static final int NO_SOCKET_FOUND=4;


String bluetooth_message="00";




@SuppressLint("HandlerLeak")
Handler mHandler=new Handler()
{
    @Override
    public void handleMessage(Message msg_type) {
        super.handleMessage(msg_type);

        switch (msg_type.what){
            case MESSAGE_READ:

                byte[] readbuf=(byte[])msg_type.obj;
                String string_recieved=new String(readbuf);

                //do some task based on recieved string

                break;
            case MESSAGE_WRITE:

                if(msg_type.obj!=null){
                    ConnectedThread connectedThread=new ConnectedThread((BluetoothSocket)msg_type.obj);
                    connectedThread.write(bluetooth_message.getBytes());

                }
                break;

            case CONNECTED:
                Toast.makeText(getApplicationContext(),"Connected",Toast.LENGTH_SHORT).show();
                break;

            case CONNECTING:
                Toast.makeText(getApplicationContext(),"Connecting...",Toast.LENGTH_SHORT).show();
                break;

            case NO_SOCKET_FOUND:
                Toast.makeText(getApplicationContext(),"No socket found",Toast.LENGTH_SHORT).show();
                break;
        }
    }
};



@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.multiplayer_bluetooth);
    initialize_layout();
    initialize_bluetooth();
    start_accepting_connection();
    initialize_clicks();

}

public void start_accepting_connection()
{
    //call this on button click as suited by you

    AcceptThread acceptThread = new AcceptThread();
    acceptThread.start();
    Toast.makeText(getApplicationContext(),"accepting",Toast.LENGTH_SHORT).show();
}
public void initialize_clicks()
{
    lv_paired_devices.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id)
        {
            Object[] objects = set_pairedDevices.toArray();
            BluetoothDevice device = (BluetoothDevice) objects[position];

            ConnectThread connectThread = new ConnectThread(device);
            connectThread.start();

            Toast.makeText(getApplicationContext(),"device choosen "+device.getName(),Toast.LENGTH_SHORT).show();
        }
    });
}

public void initialize_layout()
{
    lv_paired_devices = (ListView)findViewById(R.id.lv_paired_devices);
    adapter_paired_devices = new ArrayAdapter(getApplicationContext(),R.layout.support_simple_spinner_dropdown_item);
    lv_paired_devices.setAdapter(adapter_paired_devices);
}

public void initialize_bluetooth()
{
    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (bluetoothAdapter == null) {
        // Device doesn't support Bluetooth
        Toast.makeText(getApplicationContext(),"Your Device doesn't support bluetooth. you can play as Single player",Toast.LENGTH_SHORT).show();
        finish();
    }

    //Add these permisions before
//        <uses-permission android:name="android.permission.BLUETOOTH" />
//        <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
//        <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
//        <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

    if (!bluetoothAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
    }

    else {
        set_pairedDevices = bluetoothAdapter.getBondedDevices();

        if (set_pairedDevices.size() > 0) {

            for (BluetoothDevice device : set_pairedDevices) {
                String deviceName = device.getName();
                String deviceHardwareAddress = device.getAddress(); // MAC address

                adapter_paired_devices.add(device.getName() + "\n" + device.getAddress());
            }
        }
    }
}


public class AcceptThread extends Thread
{
    private final BluetoothServerSocket serverSocket;

    public AcceptThread() {
        BluetoothServerSocket tmp = null;
        try {
            // MY_UUID is the app's UUID string, also used by the client code
            tmp = bluetoothAdapter.listenUsingRfcommWithServiceRecord("NAME",MY_UUID);
        } catch (IOException e) { }
        serverSocket = tmp;
    }

    public void run() {
        BluetoothSocket socket = null;
        // Keep listening until exception occurs or a socket is returned
        while (true) {
            try {
                socket = serverSocket.accept();
            } catch (IOException e) {
                break;
            }

            // If a connection was accepted
            if (socket != null)
            {
                // Do work to manage the connection (in a separate thread)
                mHandler.obtainMessage(CONNECTED).sendToTarget();
            }
        }
    }
}


private class ConnectThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;

    public ConnectThread(BluetoothDevice device) {
        // Use a temporary object that is later assigned to mmSocket,
        // because mmSocket is final
        BluetoothSocket tmp = null;
        mmDevice = device;

        // Get a BluetoothSocket to connect with the given BluetoothDevice
        try {
            // MY_UUID is the app's UUID string, also used by the server code
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
        } catch (IOException e) { }
        mmSocket = tmp;
    }

    public void run() {
        // Cancel discovery because it will slow down the connection
        bluetoothAdapter.cancelDiscovery();

        try {
            // Connect the device through the socket. This will block
            // until it succeeds or throws an exception
            mHandler.obtainMessage(CONNECTING).sendToTarget();

            mmSocket.connect();
        } catch (IOException connectException) {
            // Unable to connect; close the socket and get out
            try {
                mmSocket.close();
            } catch (IOException closeException) { }
            return;
        }

        // Do work to manage the connection (in a separate thread)
//            bluetooth_message = "Initial message"
//            mHandler.obtainMessage(MESSAGE_WRITE,mmSocket).sendToTarget();
    }

    /** Will cancel an in-progress connection, and close the socket */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}
private class ConnectedThread extends Thread {

    private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;

    public ConnectedThread(BluetoothSocket socket) {
        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;

        // Get the input and output streams, using temp objects because
        // member streams are final
        try {
            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();
        } catch (IOException e) { }

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }

    public void run() {
        byte[] buffer = new byte[2];  // buffer store for the stream
        int bytes; // bytes returned from read()

        // Keep listening to the InputStream until an exception occurs
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.read(buffer);
                // Send the obtained bytes to the UI activity
                mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer).sendToTarget();

            } catch (IOException e) {
                break;
            }
        }
    }

    /* Call this from the main activity to send data to the remote device */
    public void write(byte[] bytes) {
        try {
            mmOutStream.write(bytes);
        } catch (IOException e) { }
    }

    /* Call this from the main activity to shutdown the connection */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}
}

multiplayer_bluetooth.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Challenge player"/>

    <ListView
        android:id="@+id/lv_paired_devices"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1">
    </ListView>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Make sure Device is paired"/>

</LinearLayout>

How to convert int to float in python?

You can literally convert it into float using:


float_value = float(integer_value)

Likewise, you can convert an integer back to float datatype with:


integer_value = int(float_value)

Hope it helped. I advice you to read "Build-In Functions of Python" at this link: https://docs.python.org/2/library/functions.html

Git: force user and password prompt

This is most likely because you have multiple accounts, like one private, one for work with GitHub.

SOLUTION On Windows, go to Start > Credential Manager > Windows Credentials and remove GitHub creds, then try pulling or pushing again and you will be prompted to relogin into GitHub

SOLUTION OnMac, issue following on terminal:

git remote set-url origin https://[email protected]/username/repo-name.git

by replacing 'username' with your GitHub username in both places and providing your GitHub repo name.

When do I need to use AtomicBoolean in Java?

The AtomicBoolean class gives you a boolean value that you can update atomically. Use it when you have multiple threads accessing a boolean variable.

The java.util.concurrent.atomic package overview gives you a good high-level description of what the classes in this package do and when to use them. I'd also recommend the book Java Concurrency in Practice by Brian Goetz.

Django: OperationalError No Such Table

I got through the same error when I went on to the admin panel. You ought to run this instead-: python manage.py migrate --run-syncdb. Don't forget to include migrate, I ran:

python manage.py make migrations and then python manage.py migrate

Still when the error persisted I tried it with the above suggested command.

PHP: check if any posted vars are empty - form: all fields required

I did it like this:

$missing = array();
 foreach ($_POST as $key => $value) { if ($value == "") { array_push($missing, $key);}}
 if (count($missing) > 0) {
  echo "Required fields found empty: ";
  foreach ($missing as $k => $v) { echo $v." ";}
  } else {
  unset($missing);
  // do your stuff here with the $_POST
  }

How to make war file in Eclipse

File -> Export -> Web -> WAR file

OR in Kepler follow as shown below :

enter image description here

2D Euclidean vector rotations

Rotate by 90 degress around 0,0:

x' = -y
y' = x

Rotate by 90 degress around px,py:

x' = -(y - py) + px
y' = (x - px) + py

mysql stored-procedure: out parameter

SET out_number=SQRT(input_number); 

Instead of this write:

select SQRT(input_number); 

Please don't write SET out_number and your input parameter should be:

PROCEDURE `test`.`my_sqrt`(IN input_number INT, OUT out_number FLOAT) 

WP -- Get posts by category?

You can use 'category_name' in parameters. http://codex.wordpress.org/Template_Tags/get_posts

Note: The category_name parameter needs to be a string, in this case, the category name.

How to add a Try/Catch to SQL Stored Procedure

Error-Handling with SQL Stored Procedures

TRY/CATCH error handling can take place either within or outside of a procedure (or both). The examples below demonstrate error handling in both cases.

If you want to experiment further, you can fork the query on Stack Exchange Data Explorer.

(This uses a temporary stored procedure... we can't create regular SP's on SEDE, but the functionality is the same.)

--our Stored Procedure
create procedure #myProc as --we can only create #temporary stored procedures on SEDE. 
  begin
    BEGIN TRY
      print 'This is our Stored Procedure.'
      print 1/0                          --<-- generate a "Divide By Zero" error.
      print 'We are not going to make it to this line.'
    END TRY

    BEGIN CATCH
      print 'This is the CATCH block within our Stored Procedure:'
          + ' Error Line #'+convert(varchar,ERROR_LINE())
          + ' of procedure '+isnull(ERROR_PROCEDURE(),'(Main)')
      --print 1/0                        --<-- generate another "Divide By Zero" error.
        -- uncomment the line above to cause error within the CATCH ¹ 
    END CATCH
  end
go

--our MAIN code block:
BEGIN TRY
  print 'This is our MAIN Procedure.'
  execute #myProc  --execute the Stored Procedure
      --print 1/0                        --<-- generate another "Divide By Zero" error.
        -- uncomment the line above to cause error within the MAIN Procedure ²
  print 'Now our MAIN sql code block continues.'
END TRY

BEGIN CATCH
  print 'This is the CATCH block for our MAIN sql code block:'
          + ' Error Line #'+convert(varchar,ERROR_LINE())
          + ' of procedure '+isnull(ERROR_PROCEDURE(),'(Main)')
END CATCH

Here's the result of running the above sql as-is:

This is our MAIN Procedure.
This is our Stored Procedure.
This is the CATCH block within our Stored Procedure: Error Line #5 of procedure #myProc
Now our MAIN sql code block continues.

¹ Uncommenting the "additional error line" from the Stored Procedure's CATCH block will produce:

This is our MAIN procedure.
This is our Stored Procedure.
This is the CATCH block within our Stored Procedure: Error Line #5 of procedure #myProc
This is the CATCH block for our MAIN sql code block: Error Line #13 of procedure #myProc

² Uncommenting the "additional error line" from the MAIN procedure will produce:

This is our MAIN Procedure.
This is our Stored Pprocedure.
This is the CATCH block within our Stored Procedure: Error Line #5 of procedure #myProc
This is the CATCH block for our MAIN sql code block: Error Line #4 of procedure (Main)

Use a single procedure for error handling

On topic of stored procedures and error handling, it can be helpful (and tidier) to use a single, dynamic, stored procedure to handle errors for multiple other procedures or code sections.

Here's an example:

--our error handling procedure
create procedure #myErrorHandling as
  begin
    print ' Error #'+convert(varchar,ERROR_NUMBER())+': '+ERROR_MESSAGE()  
    print ' occurred on line #'+convert(varchar,ERROR_LINE())
         +' of procedure '+isnull(ERROR_PROCEDURE(),'(Main)')
    if ERROR_PROCEDURE() is null       --check if error was in MAIN Procedure
      print '*Execution cannot continue after an error in the MAIN Procedure.'
  end
go

create procedure #myProc as     --our test Stored Procedure
  begin
    BEGIN TRY
      print 'This is our Stored Procedure.'
      print 1/0                       --generate a "Divide By Zero" error.
      print 'We will not make it to this line.'
    END TRY
    BEGIN CATCH
     execute #myErrorHandling
    END CATCH
  end
go

BEGIN TRY                       --our MAIN Procedure
  print 'This is our MAIN Procedure.'
  execute #myProc                     --execute the Stored Procedure
  print '*The error halted the procedure, but our MAIN code can continue.'
  print 1/0                           --generate another "Divide By Zero" error.
  print 'We will not make it to this line.'
END TRY
BEGIN CATCH
  execute #myErrorHandling
END CATCH

Example Output: (This query can be forked on SEDE here.)

This is our MAIN procedure.
This is our stored procedure.
 Error #8134: Divide by zero error encountered.
 occurred on line #5 of procedure #myProc
*The error halted the procedure, but our MAIN code can continue.
 Error #8134: Divide by zero error encountered.
 occurred on line #5 of procedure (Main)
*Execution cannot continue after an error in the MAIN procedure.

Documentation:

In the scope of a TRY/CATCH block, the following system functions can be used to obtain information about the error that caused the CATCH block to be executed:

  • ERROR_NUMBER() returns the number of the error.
  • ERROR_SEVERITY() returns the severity.
  • ERROR_STATE() returns the error state number.
  • ERROR_PROCEDURE() returns the name of the stored procedure or trigger where the error occurred.
  • ERROR_LINE() returns the line number inside the routine that caused the error.
  • ERROR_MESSAGE() returns the complete text of the error message. The text includes the values supplied for any substitutable parameters, such as lengths, object names, or times.

(Source)

Note that there are two types of SQL errors: Terminal and Catchable. TRY/CATCH will [obviously] only catch the "Catchable" errors. This is one of a number of ways of learning more about your SQL errors, but it probably the most useful.

It's "better to fail now" (during development) compared to later because, as Homer says . . .

Integer value in TextView

If you want it to display on your layout you should

For example:

activity_layout.XML file

    <TextView
        android:id="@+id/example_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

On the activity.java file

    final TextView textView = findViewById(R.id.example_tv);
    textView.setText(Integer.toString(yourNumberHere));

In the first line on the XML file you can see:

android:id="@+id/example_tv"

That's where you get the id to change in the .java file for the findViewById(R.id.example_tv)

Hope I made myself clear, I just went with this explanation because a lot of times people seem to know the ".setText()" method, they just can't change the text in the "UI".


EDIT Since this is a fairly old answer, and Kotlin is the preferred language for Android development, here's its counterpart.

With the same XML layout:

You can either use the findViewbyId() or use Kotlin synthetic properties:

findViewById<TextView>(R.id.example_tv).text = yourNumberHere.toString()

// Or

example_tv?.text = yourNumberHere.toString()

The toString() is from Kotlin's Any object (comparable to the Java Object):

The root of the Kotlin class hierarchy. Every Kotlin class has Any as a superclass.

What is a thread exit code?

There actually doesn't seem to be a lot of explanation on this subject apparently but the exit codes are supposed to be used to give an indication on how the thread exited, 0 tends to mean that it exited safely whilst anything else tends to mean it didn't exit as expected. But then this exit code can be set in code by yourself to completely overlook this.

The closest link I could find to be useful for more information is this

Quote from above link:

What ever the method of exiting, the integer that you return from your process or thread must be values from 0-255(8bits). A zero value indicates success, while a non zero value indicates failure. Although, you can attempt to return any integer value as an exit code, only the lowest byte of the integer is returned from your process or thread as part of an exit code. The higher order bytes are used by the operating system to convey special information about the process. The exit code is very useful in batch/shell programs which conditionally execute other programs depending on the success or failure of one.


From the Documentation for GetEXitCodeThread

Important The GetExitCodeThread function returns a valid error code defined by the application only after the thread terminates. Therefore, an application should not use STILL_ACTIVE (259) as an error code. If a thread returns STILL_ACTIVE (259) as an error code, applications that test for this value could interpret it to mean that the thread is still running and continue to test for the completion of the thread after the thread has terminated, which could put the application into an infinite loop.


My understanding of all this is that the exit code doesn't matter all that much if you are using threads within your own application for your own application. The exception to this is possibly if you are running a couple of threads at the same time that have a dependency on each other. If there is a requirement for an outside source to read this error code, then you can set it to let other applications know the status of your thread.

How to set thymeleaf th:field value from other variable

If you don't have to come back on the page with keeping form's value, you can do that :

<form method="post" th:action="@{''}" th:object="${form}">
    <input class="form-control"
           type="text"
           th:field="${client.name}"/>

It's some kind of magic :

  • it will set the value = client.name
  • it will send back the value in the form, as 'name' field. So you would have to change your form field, 'clientName' to 'name'

If you matter keeping you form's input values, like a back on the page with an user input mistake, then you will have to do that :

<form method="post" th:action="@{''}" th:object="${form}">
    <input class="form-control"
           type="text"
           th:name="name"
           th:value="${form.name != null} ? ${form.name} : ${client.name}"/>

That means :

  • The form field name is 'name'
  • The value is taken from the form if it exists, else from the client bean. Which matches the first arrival on the page with initial value, then the forms input values if there is an error.

Without having to map your client bean to your form bean. And it works because once you submitted the form, the value arn't null but "" (empty)

How to my "exe" from PyCharm project

You cannot directly save a Python file as an exe and expect it to work -- the computer cannot automatically understand whatever code you happened to type in a text file. Instead, you need to use another program to transform your Python code into an exe.

I recommend using a program like Pyinstaller. It essentially takes the Python interpreter and bundles it with your script to turn it into a standalone exe that can be run on arbitrary computers that don't have Python installed (typically Windows computers, since Linux tends to come pre-installed with Python).

To install it, you can either download it from the linked website or use the command:

pip install pyinstaller

...from the command line. Then, for the most part, you simply navigate to the folder containing your source code via the command line and run:

pyinstaller myscript.py

You can find more information about how to use Pyinstaller and customize the build process via the documentation.


You don't necessarily have to use Pyinstaller, though. Here's a comparison of different programs that can be used to turn your Python code into an executable.

Difference between Visual Basic 6.0 and VBA

For nearly all programming purposes, VBA and VB 6.0 are the same thing.

VBA cannot compile your program into an executable binary. You'll always need the host (a Word file and MS Word, for example) to contain and execute your project. You'll also not be able to create COM DLLs with VBA.

Apart from that, there is a difference in the IDE - the VB 6.0 IDE is more powerful in comparison. On the other hand, you have tight integration of the host application in VBA. Application-global objects (like "ActiveDocument") and events are available without declaration, so application-specific programming is straight-forward.

Still, nothing keeps you from firing up Word, loading the VBA IDE and solving a problem that has no relation to Word whatsoever. I'm not sure if there is anything that VB 6.0 can do (technically), and VBA cannot. I'm looking for a comparison sheet on the MSDN though.

How to get N rows starting from row M from sorted table in T-SQL

If you want to select 100 records from 25th record:

select TOP 100 * from TableName
where PrimaryKeyField 
   NOT IN(Select TOP 24 PrimaryKeyField from TableName);

Git "error: The branch 'x' is not fully merged"

As Drew Taylor pointed out, branch deletion with -d only considers the current HEAD in determining if the branch is "fully merged". It will complain even if the branch is merged with some other branch. The error message could definitely be clearer in this regard... You can either checkout the merged branch before deleting, or just use git branch -D. The capital -D will override the check entirely.

Convert string to nullable type (int, double, etc...)

There is a generic solution (for any type). Usability is good, but implementation should be improved: http://cleansharp.de/wordpress/2011/05/generischer-typeconverter/

This allows you to write very clean code like this:

string value = null;
int? x = value.ConvertOrDefault<int?>();

and also:

object obj = 1;  

string value = null;
int x = 5;
if (value.TryConvert(out x))
    Console.WriteLine("TryConvert example: " + x); 

bool boolean = "false".ConvertOrDefault<bool>();
bool? nullableBoolean = "".ConvertOrDefault<bool?>();
int integer = obj.ConvertOrDefault<int>();
int negativeInteger = "-12123".ConvertOrDefault<int>();
int? nullableInteger = value.ConvertOrDefault<int?>();
MyEnum enumValue = "SecondValue".ConvertOrDefault<MyEnum>();

MyObjectBase myObject = new MyObjectClassA();
MyObjectClassA myObjectClassA = myObject.ConvertOrDefault<MyObjectClassA>();

Error: JavaFX runtime components are missing, and are required to run this application with JDK 11

This worked for me:

File >> Project Structure >> Modules >> Dependency >> + (on left-side of window)

clicking the "+" sign will let you designate the directory where you have unpacked JavaFX's "lib" folder.

Scope is Compile (which is the default.) You can then edit this to call it JavaFX by double-clicking on the line.

then in:

Run >> Edit Configurations

Add this line to VM Options:

--module-path /path/to/JavaFX/lib --add-modules=javafx.controls

(oh and don't forget to set the SDK)

Post order traversal of binary tree without recursion

Here's a sample from wikipedia:

nonRecursivePostorder(rootNode)
  nodeStack.push(rootNode)
  while (! nodeStack.empty())
    currNode = nodeStack.peek()
    if ((currNode.left != null) and (currNode.left.visited == false))
      nodeStack.push(currNode.left)
    else 
      if ((currNode.right != null) and (currNode.right.visited == false))
        nodeStack.push(currNode.right)
      else
        print currNode.value
        currNode.visited := true
        nodeStack.pop()

Get push notification while App in foreground iOS

If your application is in foreground state, it means you are currently using the same app. So there is no need to show notification on the top generally.

But still if you want to show notification in that case you have to create your custom Alert View or Custom View like Toast or something else to show to the user that you have got a notification.

You can also show a badge on the top if you have such kind of feature in your app.

Using prepared statements with JDBCTemplate

I'd factor out the prepared statement handling to at least a method. In this case, because there are no results it is fairly simple (and assuming that the connection is an instance variable that doesn't change):

private PreparedStatement updateSales;
public void updateSales(int sales, String cof_name) throws SQLException {
    if (updateSales == null) {
        updateSales = con.prepareStatement(
            "UPDATE COFFEES SET SALES = ? WHERE COF_NAME LIKE ?");
    }
    updateSales.setInt(1, sales);
    updateSales.setString(2, cof_name);
    updateSales.executeUpdate();
}

At that point, it is then just a matter of calling:

updateSales(75, "Colombian");

Which is pretty simple to integrate with other things, yes? And if you call the method many times, the update will only be constructed once and that will make things much faster. Well, assuming you don't do crazy things like doing each update in its own transaction...

Note that the types are fixed. This is because for any particular query/update, they should be fixed so as to allow the database to do its job efficiently. If you're just pulling arbitrary strings from a CSV file, pass them in as strings. There's also no locking; far better to keep individual connections to being used from a single thread instead.

How do you initialise a dynamic array in C++?

char* c = new char[length]();

Update Rows in SSIS OLEDB Destination

Use Lookupstage to decide whether to insert or update. Check this link for more info - http://beingoyen.blogspot.com/2010/03/ssis-how-to-update-instead-of-insert.html

Steps to do update:

  1. Drag OLEDB Command [instead of oledb destination]
  2. Go to properties window
  3. Under Custom properties select SQLCOMMAND and insert update command ex:

    UPDATE table1 SET col1 = ?, col2 = ? where id = ?

  4. map columns in exact order from source to output as in update command

How to scroll to specific item using jQuery?

I managed to do it myself. No need for any plugins. Check out my gist:

// Replace #fromA with your button/control and #toB with the target to which     
// You wanna scroll to. 
//
$("#fromA").click(function() {
    $("html, body").animate({ scrollTop: $("#toB").offset().top }, 1500);
});

Determine if JavaScript value is an "integer"?

Use jQuery's IsNumeric method.

http://api.jquery.com/jQuery.isNumeric/

if ($.isNumeric(id)) {
   //it's numeric
}

CORRECTION: that would not ensure an integer. This would:

if ( (id+"").match(/^\d+$/) ) {
   //it's all digits
}

That, of course, doesn't use jQuery, but I assume jQuery isn't actually mandatory as long as the solution works

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.5 or one of its dependencies could not be resolved

Couple of things to try:

  1. Doublecheck the location of the local artifact repo configured in your settings.xml file (at the following location {your home folder}/.m2/settings.xml). Are you sure the local repo is where you think it is? (Yes, a mistake I've made in the past...)
  2. Remove entire contents of artifact repo on the new build machine (or at least anything related to Maven). You mentioned doing some artifact repo cleanup but I'm not sure what directory(ies) you removed. I've run into weird issues like these when a jar was corrupted.
  3. Make sure you have enough disk space/quota for the local artifact repo. I have run into weird issues when I didn't have a large enough quota to hold all the artifacts, likely caused by partially downloaded jar files.
  4. Try running with plain Maven on the command line; take Eclipse and m2e out of the equation. mvn -U dependency:resolve should do it. The -U forces Maven to download no matter what your repository update policies are. Add -X to get detailed debug logging.
  5. Copy settings.xml from MAVEN_HOME\conf\ to USER_HOME.m2. Add proxies (if needed) in case you are behind a proxy server.

Auto Scale TextView Text to Fit within Bounds

As a mobile developer, I was sad to find nothing native that supports auto resizing. My searches did not turn up anything that worked for me and in the end, I spent the better half of my weekend and created my own auto resize text view. I will post the code here and hopefully it will be useful for someone else.

This class uses a static layout with the text paint of the original text view to measure the height. From there, I step down by 2 font pixels and remeasure until I have a size that fits. At the end, if the text still does not fit, I append an ellipsis. I had requirements to animate the text and reuse views and this seems to work well on the devices I have and seems to run fast enough for me.

/**
 *               DO WHAT YOU WANT TO PUBLIC LICENSE
 *                    Version 2, December 2004
 * 
 * Copyright (C) 2004 Sam Hocevar <[email protected]>
 * 
 * Everyone is permitted to copy and distribute verbatim or modified
 * copies of this license document, and changing it is allowed as long
 * as the name is changed.
 * 
 *            DO WHAT YOU WANT TO PUBLIC LICENSE
 *   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
 * 
 *  0. You just DO WHAT YOU WANT TO.
 */

import android.content.Context;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;

/**
 * Text view that auto adjusts text size to fit within the view.
 * If the text size equals the minimum text size and still does not
 * fit, append with an ellipsis.
 * 
 * @author Chase Colburn
 * @since Apr 4, 2011
 */
public class AutoResizeTextView extends TextView {

    // Minimum text size for this text view
    public static final float MIN_TEXT_SIZE = 20;

    // Interface for resize notifications
    public interface OnTextResizeListener {
        public void onTextResize(TextView textView, float oldSize, float newSize);
    }

    // Our ellipse string
    private static final String mEllipsis = "...";

    // Registered resize listener
    private OnTextResizeListener mTextResizeListener;

    // Flag for text and/or size changes to force a resize
    private boolean mNeedsResize = false;

    // Text size that is set from code. This acts as a starting point for resizing
    private float mTextSize;

    // Temporary upper bounds on the starting text size
    private float mMaxTextSize = 0;

    // Lower bounds for text size
    private float mMinTextSize = MIN_TEXT_SIZE;

    // Text view line spacing multiplier
    private float mSpacingMult = 1.0f;

    // Text view additional line spacing
    private float mSpacingAdd = 0.0f;

    // Add ellipsis to text that overflows at the smallest text size
    private boolean mAddEllipsis = true;

    // Default constructor override
    public AutoResizeTextView(Context context) {
        this(context, null);
    }

    // Default constructor when inflating from XML file
    public AutoResizeTextView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    // Default constructor override
    public AutoResizeTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mTextSize = getTextSize();
    }

    /**
     * When text changes, set the force resize flag to true and reset the text size.
     */
    @Override
    protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
        mNeedsResize = true;
        // Since this view may be reused, it is good to reset the text size
        resetTextSize();
    }

    /**
     * If the text view size changed, set the force resize flag to true
     */
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        if (w != oldw || h != oldh) {
            mNeedsResize = true;
        }
    }

    /**
     * Register listener to receive resize notifications
     * @param listener
     */
    public void setOnResizeListener(OnTextResizeListener listener) {
        mTextResizeListener = listener;
    }

    /**
     * Override the set text size to update our internal reference values
     */
    @Override
    public void setTextSize(float size) {
        super.setTextSize(size);
        mTextSize = getTextSize();
    }

    /**
     * Override the set text size to update our internal reference values
     */
    @Override
    public void setTextSize(int unit, float size) {
        super.setTextSize(unit, size);
        mTextSize = getTextSize();
    }

    /**
     * Override the set line spacing to update our internal reference values
     */
    @Override
    public void setLineSpacing(float add, float mult) {
        super.setLineSpacing(add, mult);
        mSpacingMult = mult;
        mSpacingAdd = add;
    }

    /**
     * Set the upper text size limit and invalidate the view
     * @param maxTextSize
     */
    public void setMaxTextSize(float maxTextSize) {
        mMaxTextSize = maxTextSize;
        requestLayout();
        invalidate();
    }

    /**
     * Return upper text size limit
     * @return
     */
    public float getMaxTextSize() {
        return mMaxTextSize;
    }

    /**
     * Set the lower text size limit and invalidate the view
     * @param minTextSize
     */
    public void setMinTextSize(float minTextSize) {
        mMinTextSize = minTextSize;
        requestLayout();
        invalidate();
    }

    /**
     * Return lower text size limit
     * @return
     */
    public float getMinTextSize() {
        return mMinTextSize;
    }

    /**
     * Set flag to add ellipsis to text that overflows at the smallest text size
     * @param addEllipsis
     */
    public void setAddEllipsis(boolean addEllipsis) {
        mAddEllipsis = addEllipsis;
    }

    /**
     * Return flag to add ellipsis to text that overflows at the smallest text size
     * @return
     */
    public boolean getAddEllipsis() {
        return mAddEllipsis;
    }

    /**
     * Reset the text to the original size
     */
    public void resetTextSize() {
        if (mTextSize > 0) {
            super.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
            mMaxTextSize = mTextSize;
        }
    }

    /**
     * Resize text after measuring
     */
    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        if (changed || mNeedsResize) {
            int widthLimit = (right - left) - getCompoundPaddingLeft() - getCompoundPaddingRight();
            int heightLimit = (bottom - top) - getCompoundPaddingBottom() - getCompoundPaddingTop();
            resizeText(widthLimit, heightLimit);
        }
        super.onLayout(changed, left, top, right, bottom);
    }

    /**
     * Resize the text size with default width and height
     */
    public void resizeText() {

        int heightLimit = getHeight() - getPaddingBottom() - getPaddingTop();
        int widthLimit = getWidth() - getPaddingLeft() - getPaddingRight();
        resizeText(widthLimit, heightLimit);
    }

    /**
     * Resize the text size with specified width and height
     * @param width
     * @param height
     */
    public void resizeText(int width, int height) {
        CharSequence text = getText();
        // Do not resize if the view does not have dimensions or there is no text
        if (text == null || text.length() == 0 || height <= 0 || width <= 0 || mTextSize == 0) {
            return;
        }

        if (getTransformationMethod() != null) {
            text = getTransformationMethod().getTransformation(text, this);
        }

        // Get the text view's paint object
        TextPaint textPaint = getPaint();

        // Store the current text size
        float oldTextSize = textPaint.getTextSize();
        // If there is a max text size set, use the lesser of that and the default text size
        float targetTextSize = mMaxTextSize > 0 ? Math.min(mTextSize, mMaxTextSize) : mTextSize;

        // Get the required text height
        int textHeight = getTextHeight(text, textPaint, width, targetTextSize);

        // Until we either fit within our text view or we had reached our min text size, incrementally try smaller sizes
        while (textHeight > height && targetTextSize > mMinTextSize) {
            targetTextSize = Math.max(targetTextSize - 2, mMinTextSize);
            textHeight = getTextHeight(text, textPaint, width, targetTextSize);
        }

        // If we had reached our minimum text size and still don't fit, append an ellipsis
        if (mAddEllipsis && targetTextSize == mMinTextSize && textHeight > height) {
            // Draw using a static layout
            // modified: use a copy of TextPaint for measuring
            TextPaint paint = new TextPaint(textPaint);
            // Draw using a static layout
            StaticLayout layout = new StaticLayout(text, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, false);
            // Check that we have a least one line of rendered text
            if (layout.getLineCount() > 0) {
                // Since the line at the specific vertical position would be cut off,
                // we must trim up to the previous line
                int lastLine = layout.getLineForVertical(height) - 1;
                // If the text would not even fit on a single line, clear it
                if (lastLine < 0) {
                    setText("");
                }
                // Otherwise, trim to the previous line and add an ellipsis
                else {
                    int start = layout.getLineStart(lastLine);
                    int end = layout.getLineEnd(lastLine);
                    float lineWidth = layout.getLineWidth(lastLine);
                    float ellipseWidth = textPaint.measureText(mEllipsis);

                    // Trim characters off until we have enough room to draw the ellipsis
                    while (width < lineWidth + ellipseWidth) {
                        lineWidth = textPaint.measureText(text.subSequence(start, --end + 1).toString());
                    }
                    setText(text.subSequence(0, end) + mEllipsis);
                }
            }
        }

        // Some devices try to auto adjust line spacing, so force default line spacing
        // and invalidate the layout as a side effect
        setTextSize(TypedValue.COMPLEX_UNIT_PX, targetTextSize);
        setLineSpacing(mSpacingAdd, mSpacingMult);

        // Notify the listener if registered
        if (mTextResizeListener != null) {
            mTextResizeListener.onTextResize(this, oldTextSize, targetTextSize);
        }

        // Reset force resize flag
        mNeedsResize = false;
    }

    // Set the text size of the text paint object and use a static layout to render text off screen before measuring
    private int getTextHeight(CharSequence source, TextPaint paint, int width, float textSize) {
        // modified: make a copy of the original TextPaint object for measuring
        // (apparently the object gets modified while measuring, see also the
        // docs for TextView.getPaint() (which states to access it read-only)
        TextPaint paintCopy = new TextPaint(paint);
        // Update the text paint object
        paintCopy.setTextSize(textSize);
        // Measure using a static layout
        StaticLayout layout = new StaticLayout(source, paintCopy, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
        return layout.getHeight();
    }

}

Warning. There is an important fixed bug affecting Android 3.1 - 4.04 causing all AutoResizingTextView widgets not to work. Please read: https://stackoverflow.com/a/21851157/2075875

How can change width of dropdown list?

Try this code:

<select name="wgtmsr" id="wgtmsr">
<option value="kg">Kg</option>
<option value="gm">Gm</option>
<option value="pound">Pound</option>
<option value="MetricTon">Metric ton</option>
<option value="litre">Litre</option>
<option value="ounce">Ounce</option>
</select>

CSS:

#wgtmsr{
 width:150px;   
}

If you want to change the width of the option you can do this in your css:

#wgtmsr option{
  width:150px;   
}

Maybe you have a conflict in your css rules that override the width of your select

DEMO

Error Code 1292 - Truncated incorrect DOUBLE value - Mysql

Had this issue with ES6 and TypeORM while trying to pass .where("order.id IN (:orders)", { orders }), where orders was a comma separated string of numbers. When I converted to a template literal, the problem was resolved.

.where(`order.id IN (${orders})`);

MySQL error code: 1175 during UPDATE in MySQL Workbench

All that's needed is: Start a new query and run:

SET SQL_SAFE_UPDATES = 0;

Then: Run the query that you were trying to run that wasn't previously working.

Replace words in the body text

Wanted to add an example to funky-future's answer as I kept getting this error:

Uncaught TypeError: element.childNodes is not iterable

use like this:

replaceInText(document.body,"search term","replacement");

it didn't work for me with jQuery selectors.

How do I add a Font Awesome icon to input field?

to work this with unicode or fontawesome, you should add a span with class like below, because input tag not support pseudo classes like :after. this is not a direct solution

in html:

   <span class="button1 search"></span>
<input name="username">

in css:

.button1 {
    background-color: #B9D5AD;
    border-radius: 0.2em 0 0 0.2em;
    box-shadow: 1px 0 0 rgba(0, 0, 0, 0.5), 2px 0 0 rgba(255, 255, 255, 0.5); 
    pointer-events: none;
    margin:1px 12px;    
    border-radius: 0.2em;    
    color: #333333;
    cursor: pointer;
    position: absolute;
    padding: 3px;
    text-decoration: none;   

}

When to use AtomicReference in Java?

You can use AtomicReference when applying optimistic locks. You have a shared object and you want to change it from more than 1 thread.

  1. You can create a copy of the shared object
  2. Modify the shared object
  3. You need to check that the shared object is still the same as before - if yes, then update with the reference of the modified copy.

As other thread might have modified it and/can modify between these 2 steps. You need to do it in an atomic operation. this is where AtomicReference can help

Plotting a fast Fourier transform in Python

The high spike that you have is due to the DC (non-varying, i.e. freq = 0) portion of your signal. It's an issue of scale. If you want to see non-DC frequency content, for visualization, you may need to plot from the offset 1 not from offset 0 of the FFT of the signal.

Modifying the example given above by @PaulH

import numpy as np
import matplotlib.pyplot as plt
import scipy.fftpack

# Number of samplepoints
N = 600
# sample spacing
T = 1.0 / 800.0
x = np.linspace(0.0, N*T, N)
y = 10 + np.sin(50.0 * 2.0*np.pi*x) + 0.5*np.sin(80.0 * 2.0*np.pi*x)
yf = scipy.fftpack.fft(y)
xf = np.linspace(0.0, 1.0/(2.0*T), N/2)

plt.subplot(2, 1, 1)
plt.plot(xf, 2.0/N * np.abs(yf[0:N/2]))
plt.subplot(2, 1, 2)
plt.plot(xf[1:], 2.0/N * np.abs(yf[0:N/2])[1:])

The output plots: Ploting FFT signal with DC and then when removing it (skipping freq = 0)

Another way, is to visualize the data in log scale:

Using:

plt.semilogy(xf, 2.0/N * np.abs(yf[0:N/2]))

Will show: enter image description here

Are there constants in JavaScript?

Since ES2015, JavaScript has a notion of const:

const MY_CONSTANT = "some-value";

This will work in pretty much all browsers except IE 8, 9 and 10. Some may also need strict mode enabled.

You can use var with conventions like ALL_CAPS to show that certain values should not be modified if you need to support older browsers or are working with legacy code:

var MY_CONSTANT = "some-value";

How can I set the request header for curl?

Just use the -H parameter several times:

curl -H "Accept-Charset: utf-8" -H "Content-Type: application/x-www-form-urlencoded" http://www.some-domain.com

Excel Macro - Select all cells with data and format as table

Try this one for current selection:

Sub A_SelectAllMakeTable2()
    Dim tbl As ListObject
    Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, Selection, , xlYes)
    tbl.TableStyle = "TableStyleMedium15"
End Sub

or equivalent of your macro (for Ctrl+Shift+End range selection):

Sub A_SelectAllMakeTable()
    Dim tbl As ListObject
    Dim rng As Range

    Set rng = Range(Range("A1"), Range("A1").SpecialCells(xlLastCell))
    Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, rng, , xlYes)
    tbl.TableStyle = "TableStyleMedium15"
End Sub

How can I join elements of an array in Bash?

Surprisingly my solution is not yet given :) This is the simplest way for me. It doesn't need a function:

IFS=, eval 'joined="${foo[*]}"'

Note: This solution was observed to work well in non-POSIX mode. In POSIX mode, the elements are still joined properly, but IFS=, becomes permanent.

How to check the function's return value if true or false

you're comparing the result against a string ('false') not the built-in negative constant (false)

just use

if(ValidateForm() == false) {

or better yet

if(!ValidateForm()) {

also why are you calling validateForm twice?

Sound alarm when code finishes

Why use python at all? You might forget to remove it and check it into a repository. Just run your python command with && and another command to run to do the alerting.

python myscript.py && 
    notify-send 'Alert' 'Your task is complete' && 
    paplay /usr/share/sounds/freedesktop/stereo/suspend-error.oga

or drop a function into your .bashrc. I use apython here but you could override 'python'

function apython() {
    /usr/bin/python $*
    notify-send 'Alert' "python $* is complete"
    paplay /usr/share/sounds/freedesktop/stereo/suspend-error.oga
}

Determine the process pid listening on a certain port

on windows, the netstat option to get the pid's is -o and -p selects a protocol filter, ex.: netstat -a -p tcp -o

How to use Servlets and Ajax?

Using bootstrap multi select

Ajax

function() { $.ajax({
    type : "get",
    url : "OperatorController",
    data : "input=" + $('#province').val(),
    success : function(msg) {
    var arrayOfObjects = eval(msg); 
    $("#operators").multiselect('dataprovider',
    arrayOfObjects);
    // $('#output').append(obj);
    },
    dataType : 'text'
    });}
}

In Servlet

request.getParameter("input")

How to see the values of a table variable at debug time in T-SQL?

I have come to the conclusion that this is not possible without any plugins.

What is the difference between NULL, '\0' and 0?

It appears that a number of people misunderstand what the differences between NULL, '\0' and 0 are. So, to explain, and in attempt to avoid repeating things said earlier:

A constant expression of type int with the value 0, or an expression of this type, cast to type void * is a null pointer constant, which if converted to a pointer becomes a null pointer. It is guaranteed by the standard to compare unequal to any pointer to any object or function.

NULL is a macro, defined in as a null pointer constant.

\0 is a construction used to represent the null character, used to terminate a string.

A null character is a byte which has all its bits set to 0.

How to specify a min but no max decimal using the range data annotation attribute?

I would put decimal.MaxValue.ToString() since this is the effective ceiling for the decmial type it is equivalent to not having an upper bound.

How to use LDFLAGS in makefile

Seems like the order of the linking flags was not an issue in older versions of gcc. Eg gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16) comes with Centos-6.7 happy with linker option before inputfile; but gcc with ubuntu 16.04 gcc (Ubuntu 5.3.1-14ubuntu2.1) 5.3.1 20160413 does not allow.

Its not the gcc version alone, I has got something to with the distros

How to insert spaces/tabs in text using HTML/CSS

To insert tab space between two words/sentences I usually use

&emsp; and &ensp;

Disable F5 and browser refresh using JavaScript

You can directly use hotkey from rich faces if you are using JSF.

<rich:hotKey key="backspace" onkeydown="if (event.keyCode == 8) return false;" handler="return false;" disableInInput="true" />
<rich:hotKey key="f5" onkeydown="if (event.keyCode == 116) return false;" handler="return false;" disableInInput="true" />
<rich:hotKey key="ctrl+R" onkeydown="if (event.keyCode == 123) return false;" handler="return false;" disableInInput="true" />
<rich:hotKey key="ctrl+f5" onkeydown="if (event.keyCode == 154) return false;" handler="return false;" disableInInput="true" /> 

How to change credentials for SVN repository in Eclipse?

My wife suggested:

  1. Open SVN Repositories View
  2. Open Location Properties...
  3. Show Credentials For: press [X] button
  4. Select user, write password, press [Finish]

and all work!!!

Twitter Bootstrap dropdown menu

<script type="text/javascript" src="http://twitter.github.com/bootstrap/assets/js/bootstrap-dropdown.js"></script>

What does ellipsize mean in android?

Use ellipsize when you have fixed width, then it will automatically truncate the text & show the ellipsis at end,

it Won't work if you set layout_width as wrap_content & match_parent.

android:width="40dp"
android:ellipsize="end"
android:singleLine="true"

Rendering React Components from Array of Objects

this.data presumably contains all the data, so you would need to do something like this:

var stations = [];
var stationData = this.data.stations;

for (var i = 0; i < stationData.length; i++) {
    stations.push(
        <div key={stationData[i].call} className="station">
            Call: {stationData[i].call}, Freq: {stationData[i].frequency}
        </div>
    )
}

render() {
  return (
    <div className="stations">{stations}</div>
  )
}

Or you can use map and arrow functions if you're using ES6:

const stations = this.data.stations.map(station =>
    <div key={station.call} className="station">
      Call: {station.call}, Freq: {station.frequency}
    </div>
);

Adding a Button to a WPF DataGrid

First create a DataGridTemplateColumn to contain the button:

<DataGridTemplateColumn>
  <DataGridTemplateColumn.CellTemplate> 
    <DataTemplate> 
      <Button Click="ShowHideDetails">Details</Button> 
    </DataTemplate> 
  </DataGridTemplateColumn.CellTemplate> 
</DataGridTemplateColumn>

When the button is clicked, update the containing DataGridRow's DetailsVisibility:

void ShowHideDetails(object sender, RoutedEventArgs e)
{
    for (var vis = sender as Visual; vis != null; vis = VisualTreeHelper.GetParent(vis) as Visual)
    if (vis is DataGridRow)
    {
        var row = (DataGridRow)vis;
        row.DetailsVisibility = 
        row.DetailsVisibility == Visibility.Visible ? Visibility.Collapsed : Visibility.Visible;
        break;
    }
}

iReport not starting using JRE 8

iReport does not work with java 8.

  • if not yet installed, download and install java 7
  • find the install dir of your iReport and open the file: ireport.conf

(you will find it here: iReport-x.x.x\etc\ )

change this line:

#jdkhome="/path/to/jdk"

to this (if not this is your java 7 install dir then replace the parameter value between ""s with your installed java 7's path):

jdkhome="C:\Program Files\Java\jdk1.7.0_67"

How to replace deprecated android.support.v4.app.ActionBarDrawerToggle

you must use import android.support.v7.app.ActionBarDrawerToggle;

and use the constructor

public CustomActionBarDrawerToggle(Activity mActivity,DrawerLayout mDrawerLayout)
{
    super(mActivity, mDrawerLayout, R.string.ns_menu_open, R.string.ns_menu_close);
}

and if the drawer toggle button becomes dark then you must use the supportActionBar provided in the support library.

You can implement supportActionbar from this link: http://developer.android.com/training/basics/actionbar/setting-up.html

Position a div container on the right side

This works for me.

<div style="position: relative;width:100%;">
    <div style="position:absolute;left:0px;background-color:red;width:25%;height:100px;">
      This will be on the left
    </div>

    <div style="position:absolute;right:0px;background-color:blue;width:25%;height:100px;">
      This will be on the right
    </div>
</div>

Difference between HttpModule and HttpClientModule

There is a library which allows you to use HttpClient with strongly-typed callbacks.

The data and the error are available directly via these callbacks.

A reason for existing

When you use HttpClient with Observable, you have to use .subscribe(x=>...) in the rest of your code.

This is because Observable<HttpResponse<T>> is tied to HttpResponse.

This tightly couples the http layer with the rest of your code.

This library encapsulates the .subscribe(x => ...) part and exposes only the data and error through your Models.

With strongly-typed callbacks, you only have to deal with your Models in the rest of your code.

The library is called angular-extended-http-client.

angular-extended-http-client library on GitHub

angular-extended-http-client library on NPM

Very easy to use.

Sample usage

The strongly-typed callbacks are

Success:

  • IObservable<T>
  • IObservableHttpResponse
  • IObservableHttpCustomResponse<T>

Failure:

  • IObservableError<TError>
  • IObservableHttpError
  • IObservableHttpCustomError<TError>

Add package to your project and in your app module

import { HttpClientExtModule } from 'angular-extended-http-client';

and in the @NgModule imports

  imports: [
    .
    .
    .
    HttpClientExtModule
  ],

Your Models

//Normal response returned by the API.
export class RacingResponse {
    result: RacingItem[];
}

//Custom exception thrown by the API.
export class APIException {
    className: string;
}

Your Service

In your Service, you just create params with these callback types.

Then, pass them on to the HttpClientExt's get method.

import { Injectable, Inject } from '@angular/core'
import { RacingResponse, APIException } from '../models/models'
import { HttpClientExt, IObservable, IObservableError, ResponseType, ErrorType } from 'angular-extended-http-client';
.
.

@Injectable()
export class RacingService {

    //Inject HttpClientExt component.
    constructor(private client: HttpClientExt, @Inject(APP_CONFIG) private config: AppConfig) {

    }

    //Declare params of type IObservable<T> and IObservableError<TError>.
    //These are the success and failure callbacks.
    //The success callback will return the response objects returned by the underlying HttpClient call.
    //The failure callback will return the error objects returned by the underlying HttpClient call.
    getRaceInfo(success: IObservable<RacingResponse>, failure?: IObservableError<APIException>) {
        let url = this.config.apiEndpoint;

        this.client.get(url, ResponseType.IObservable, success, ErrorType.IObservableError, failure);
    }
}

Your Component

In your Component, your Service is injected and the getRaceInfo API called as shown below.

  ngOnInit() {    
    this.service.getRaceInfo(response => this.result = response.result,
                                error => this.errorMsg = error.className);

  }

Both, response and error returned in the callbacks are strongly typed. Eg. response is type RacingResponse and error is APIException.

You only deal with your Models in these strongly-typed callbacks.

Hence, The rest of your code only knows about your Models.

Also, you can still use the traditional route and return Observable<HttpResponse<T>> from Service API.

How to hide output of subprocess in Python 2.7

Here's a more portable version (just for fun, it is not necessary in your case):

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from subprocess import Popen, PIPE, STDOUT

try:
    from subprocess import DEVNULL # py3k
except ImportError:
    import os
    DEVNULL = open(os.devnull, 'wb')

text = u"René Descartes"
p = Popen(['espeak', '-b', '1'], stdin=PIPE, stdout=DEVNULL, stderr=STDOUT)
p.communicate(text.encode('utf-8'))
assert p.returncode == 0 # use appropriate for your program error handling here

Pandas Split Dataframe into two Dataframes at a specific row

iloc

df1 = datasX.iloc[:, :72]
df2 = datasX.iloc[:, 72:]

(iloc docs)

Code coverage with Mocha

You need an additional library for code coverage, and you are going to be blown away by how powerful and easy istanbul is. Try the following, after you get your mocha tests to pass:

npm install nyc

Now, simply place the command nyc in front of your existing test command, for example:

{
  "scripts": {
    "test": "nyc mocha"
  }
}

How to delete Certain Characters in a excel 2010 cell

Another option: =MID(A1,2,LEN(A1)-2)

Or this (for fun): =RIGHT(LEFT(A1,LEN(A1)-1),LEN(LEFT(A1,LEN(A1)-1))-1)

TypeError: Cannot read property "0" from undefined

The while increments the i. So you get:

data[1][0]
data[2][0]
data[3][0]
...

It looks like name doesn't match any of the the elements of data. So, the while still increments and you reach the end of the array. I'll suggest to use for loop.

General error: 1364 Field 'user_id' doesn't have a default value

So, after After reviewing the code again, I found the error. I am wondering how no one notice that! In the above code I wrote

Post::create(request([  // <= the error is Here!!!
    'body' => request('body'),
    'title' => request('title'),
    'user_id' => auth()->id()
]));

actually, there is no need for the request function warping the body of the create function.

// this is right
Post::create([
    'body' => request('body'),
    'title' => request('title'),
    'user_id' => auth()->id()
]);

How to connect to local instance of SQL Server 2008 Express

One of the first things that you should check is that the SQL Server (MSSQLSERVER) is started. You can go to the Services Console (services.msc) and look for SQL Server (MSSQLSERVER) to see that it is started. If not, then start the service.

You could also do this through an elevated command prompt by typing net start mssqlserver.

Difference between a theta join, equijoin and natural join

Theta Join: When you make a query for join using any operator,(e.g., =, <, >, >= etc.), then that join query comes under Theta join.

Equi Join: When you make a query for join using equality operator only, then that join query comes under Equi join.

Example:

> SELECT * FROM Emp JOIN Dept ON Emp.DeptID = Dept.DeptID;
> SELECT * FROM Emp INNER JOIN Dept USING(DeptID)
This will show:
 _________________________________________________
| Emp.Name | Emp.DeptID | Dept.Name | Dept.DeptID |
|          |            |           |             |

Note: Equi join is also a theta join!

Natural Join: a type of Equi Join which occurs implicitly by comparing all the same names columns in both tables.

Note: here, the join result has only one column for each pair of same named columns.

Example

 SELECT * FROM Emp NATURAL JOIN Dept
This will show:
 _______________________________
| DeptID | Emp.Name | Dept.Name |
|        |          |           |

Rounding to 2 decimal places in SQL

This works too. The below statement rounds to two decimal places.

SELECT ROUND(92.258,2) from dual;

get the value of DisplayName attribute

PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(foo);

foreach (PropertyDescriptor property in properties)
{
    if (property.Name == "Name")
    {
        Console.WriteLine(property.DisplayName); // Something To Name
    }
}

where foo is an instance of Class1

Where does the iPhone Simulator store its data?

I have no affiliation with this program, but if you are looking to open any of this in the finder SimPholders makes it incredibly easy.

How can I change the text inside my <span> with jQuery?

Syntax:

  • return the element's text content: $(selector).text()
  • set the element's text content to content: $(selector).text(content)
  • set the element's text content using a callback function: $(selector).text(function(index, curContent))

JQuery - Change the text of a span element

How to resize images proportionally / keeping the aspect ratio?

In order to determine the aspect ratio, you need to have a ratio to aim for.

Height

function getHeight(length, ratio) {
  var height = ((length)/(Math.sqrt((Math.pow(ratio, 2)+1))));
  return Math.round(height);
}

Width

function getWidth(length, ratio) {
  var width = ((length)/(Math.sqrt((1)/(Math.pow(ratio, 2)+1))));
  return Math.round(width);
}

In this example I use 16:10 since this the typical monitor aspect ratio.

var ratio = (16/10);
var height = getHeight(300,ratio);
var width = getWidth(height,ratio);

console.log(height);
console.log(width);

Results from above would be 147 and 300

Hibernate vs JPA vs JDO - pros and cons of each?

I made a sample WebApp in May 2012 that uses JDO 3.0 & DataNucleus 3.0 - take a look how clean it is: https://github.com/TorbenVesterager/BadAssWebApp

Okay maybe it's a little bit too clean, because I use the POJOs both for the database and the JSON client, but it's fun :)

PS: Contains a few SuppressWarnings annotations (developed in IntelliJ 11)

How do I find the absolute position of an element using jQuery?

Note that $(element).offset() tells you the position of an element relative to the document. This works great in most circumstances, but in the case of position:fixed you can get unexpected results.

If your document is longer than the viewport and you have scrolled vertically toward the bottom of the document, then your position:fixed element's offset() value will be greater than the expected value by the amount you have scrolled.

If you are looking for a value relative to the viewport (window), rather than the document on a position:fixed element, you can subtract the document's scrollTop() value from the fixed element's offset().top value. Example: $("#el").offset().top - $(document).scrollTop()

If the position:fixed element's offset parent is the document, you want to read parseInt($.css('top')) instead.

How to write a test which expects an Error to be thrown in Jasmine?

Try using an anonymous function instead:

expect( function(){ parser.parse(raw); } ).toThrow(new Error("Parsing is not possible"));

you should be passing a function into the expect(...) call. Your incorrect code:

// incorrect:
expect(parser.parse(raw)).toThrow(new Error("Parsing is not possible"));

is trying to actually call parser.parse(raw) in an attempt to pass the result into expect(...),

What algorithm for a tic-tac-toe game can I use to determine the "best move" for the AI?

What you need (for tic-tac-toe or a far more difficult game like Chess) is the minimax algorithm, or its slightly more complicated variant, alpha-beta pruning. Ordinary naive minimax will do fine for a game with as small a search space as tic-tac-toe, though.

In a nutshell, what you want to do is not to search for the move that has the best possible outcome for you, but rather for the move where the worst possible outcome is as good as possible. If you assume your opponent is playing optimally, you have to assume they will take the move that is worst for you, and therefore you have to take the move that MINimises their MAXimum gain.

Deactivate or remove the scrollbar on HTML

This makes it so if before there was a scrollbar then it makes it so the scrollbar has a display of none so you can't see it anymore. You can replace html to body or a class or ID. Hope it works for you :)

html::-webkit-scrollbar {
    display: none;
}

How to get the clicked link's href with jquery?

$(".testClick").click(function () {
         var value = $(this).attr("href");
         alert(value );     
}); 

When you use $(".className") you are getting the set of all elements that have that class. Then when you call attr it simply returns the value of the first item in the collection.

How to make Java work with SQL Server?

Indeed. The thing is that the 2008 R2 version is very tricky. The JTDs driver seems to work on some cases. In a certain server, the jTDS worked fine for an 2008 R2 instance. In another server, though, I had to use Microsoft's JBDC driver sqljdbc4.jar. But then, it would only work after setting the JRE environment to 1.6(or higher).

I used 1.5 for the other server, so I waisted a lot of time on this.

Tricky issue.

Cannot open database "test" requested by the login. The login failed. Login failed for user 'xyz\ASPNET'

Inspired by cyptus's answer I used

_dbContext.Database.CreateIfNotExists();

on EF6 before the first database contact (before DB seeding).

Angular 2 Dropdown Options Default Value

Struggled a bit with this one, but ended up with the following solution... maybe it will help someone.

HTML template:

<select (change)="onValueChanged($event.target)">
    <option *ngFor="let option of uifOptions" [value]="option.value" [selected]="option == uifSelected ? true : false">{{option.text}}</option>
</select>

Component:

import { Component, Input, Output, EventEmitter, OnInit } from '@angular/core';    
export class UifDropdownComponent implements OnInit {
    @Input() uifOptions: {value: string, text: string}[];
    @Input() uifSelectedValue: string = '';
    @Output() uifSelectedValueChange:EventEmitter<string> = new EventEmitter<string>();
    uifSelected: {value: string, text: string} = {'value':'', 'text':''};

    constructor() { }

    onValueChanged(target: HTMLSelectElement):void {
        this.uifSelectedValue = target.value;
        this.uifSelectedValueChange.emit(this.uifSelectedValue);
    }

    ngOnInit() {
        this.uifSelected = this.uifOptions.filter(o => o.value == 
        this.uifSelectedValue)[0];
    }
}

Get nodes where child node contains an attribute

Try

//book[title/@lang = 'it']

This reads:

  • get all book elements
    • that have at least one title
      • which has an attribute lang
        • with a value of "it"

You may find this helpful — it's an article entitled "XPath in Five Paragraphs" by Ronald Bourret.

But in all honesty, //book[title[@lang='it']] and the above should be equivalent, unless your XPath engine has "issues." So it could be something in the code or sample XML that you're not showing us -- for example, your sample is an XML fragment. Could it be that the root element has a namespace, and you aren't counting for that in your query? And you only told us that it didn't work, but you didn't tell us what results you did get.

Angular 2 declaring an array of objects

public mySentences:Array<Object> = [
    {id: 1, text: 'Sentence 1'},
    {id: 2, text: 'Sentence 2'},
    {id: 3, text: 'Sentence 3'},
    {id: 4, text: 'Sentenc4 '},
];

Or rather,

export interface type{
    id:number;
    text:string;
}

public mySentences:type[] = [
    {id: 1, text: 'Sentence 1'},
    {id: 2, text: 'Sentence 2'},
    {id: 3, text: 'Sentence 3'},
    {id: 4, text: 'Sentenc4 '},
];

PostgreSQL: export resulting data from SQL query to Excel/CSV

The correct script for postgres (Ubuntu) is:

COPY (SELECT * FROM tbl) TO '/var/lib/postgres/myfile1.csv';

Decrementing for loops

a = " ".join(str(i) for i in range(10, 0, -1))
print (a)

how to remove the first two columns in a file using shell (awk, sed, whatever)

Here's one way to do it with Awk that's relatively easy to understand:

awk '{print substr($0, index($0, $3))}'

This is a simple awk command with no pattern, so action inside {} is run for every input line.

The action is to simply prints the substring starting with the position of the 3rd field.

  • $0: the whole input line
  • $3: 3rd field
  • index(in, find): returns the position of find in string in
  • substr(string, start): return a substring starting at index start

If you want to use a different delimiter, such as comma, you can specify it with the -F option:

awk -F"," '{print substr($0, index($0, $3))}'

You can also operate this on a subset of the input lines by specifying a pattern before the action in {}. Only lines matching the pattern will have the action run.

awk 'pattern{print substr($0, index($0, $3))}'

Where pattern can be something such as:

  • /abcdef/: use regular expression, operates on $0 by default.
  • $1 ~ /abcdef/: operate on a specific field.
  • $1 == blabla: use string comparison
  • NR > 1: use record/line number
  • NF > 0: use field/column number

Disable / Check for Mock Location (prevent gps spoofing)

try this code its very simple and usefull

  public boolean isMockLocationEnabled() {
        boolean isMockLocation = false;
        try {
            //if marshmallow
            if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                AppOpsManager opsManager = (AppOpsManager) getApplicationContext().getSystemService(Context.APP_OPS_SERVICE);
                isMockLocation = (opsManager.checkOp(AppOpsManager.OPSTR_MOCK_LOCATION, android.os.Process.myUid(), BuildConfig.APPLICATION_ID)== AppOpsManager.MODE_ALLOWED);
            } else {
                // in marshmallow this will always return true
                isMockLocation = !android.provider.Settings.Secure.getString(getApplicationContext().getContentResolver(), "mock_location").equals("0");
            }
        } catch (Exception e) {
            return isMockLocation;
        }
        return isMockLocation;
    }

Get url parameters from a string in .NET

HttpContext.Current.Request.QueryString.Get("id");

How to generate and validate a software license key?

It is not possible to prevent software piracy completely. You can prevent casual piracy and that's what all licensing solutions out their do.

Node (machine) locked licensing is best if you want to prevent reuse of license keys. I have been using Cryptlex for about a year now for my software. It has a free plan also, so if you don't expect too many customers you can use it for free.

How to identify platform/compiler from preprocessor macros?

Here's what I use:

#ifdef _WIN32 // note the underscore: without it, it's not msdn official!
    // Windows (x64 and x86)
#elif __unix__ // all unices, not all compilers
    // Unix
#elif __linux__
    // linux
#elif __APPLE__
    // Mac OS, not sure if this is covered by __posix__ and/or __unix__ though...
#endif

EDIT: Although the above might work for the basics, remember to verify what macro you want to check for by looking at the Boost.Predef reference pages. Or just use Boost.Predef directly.

Remove tracking branches no longer on remote

I use a short method to do the trick, I recommend you to do the same as it could save some hours & give you more visibility

Just add the following snippet into your .bashrc (.bashprofile on macos).

git-cleaner() { git fetch --all --prune && git branch --merged | grep -v -E "\bmaster|preprod|dmz\b" | xargs -n 1 git branch -d ;};
  1. Fetch all remotes
  2. Get only merged branches from git
  3. Remove from this list the "protected / important" branches
  4. Remove the rest (e.g, clean and merged branches)

You'll have to edit the grep regex in order to fit to your needs (here, it prevent master, preprod and dmz from deletion)

How can I check if a Perl module is installed on my system from the command line?

What you're doing there is not recursing into directories. It is only listing the modules in the root directory of the @INC directory.

The module XML::Simple will live in one of the @INC paths under XML/Simple.pm.

What he said above to find specific modules.

CPAN explains how to find all modules here, see How to find installed modules.

How to get annotations of a member variable?

Everybody describes issue with getting annotations, but the problem is in definition of your annotation. You should to add to your annotation definition a @Retention(RetentionPolicy.RUNTIME):

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface MyAnnotation{
    int id();
}

Compare two date formats in javascript/jquery

As in your example, the fit_start_time is not later than the fit_end_time.

Try it the other way round:

var fit_start_time  = $("#fit_start_time").val(); //2013-09-5
var fit_end_time    = $("#fit_end_time").val(); //2013-09-10

if(Date.parse(fit_start_time) <= Date.parse(fit_end_time)){
    alert("Please select a different End Date.");
}

Update

Your code implies that you want to see the alert with the current variables you have. If this is the case then the above code is correct. If you're intention (as per the implication of the alert message) is to make sure their fit_start_time variable is a date that is before the fit_end_time, then your original code is fine, but the data you're getting from the jQuery .val() methods is not parsing correctly. It would help if you gave us the actual HTML which the selector is sniffing at.

How to list running screen sessions?

I'm not really sure of your question, but if all you really want is list currently opened screen session, try:

screen -ls

How can I access Oracle from Python?

Here is how my code looks like. It also shows an example of how to use query parameters using a dictionary. It works on using Python 3.6:

import cx_Oracle

CONN_INFO = {
    'host': 'xxx.xx.xxx.x',
    'port': 12345,
    'user': 'SOME_SCHEMA',
    'psw': 'SECRETE',
    'service': 'service.server.com'
}

CONN_STR = '{user}/{psw}@{host}:{port}/{service}'.format(**CONN_INFO)

QUERY = '''
    SELECT
        *
    FROM
        USER
    WHERE
        NAME = :name
'''


class DB:
    def __init__(self):
        self.conn = cx_Oracle.connect(CONN_STR)

    def query(self, query, params=None):
        cursor = self.conn.cursor()
        result = cursor.execute(query, params).fetchall()
        cursor.close()
        return result


db = DB()
result = db.query(QUERY, {'name': 'happy'})

CSS Input field text color of inputted text

I always do input prompts, like this:

    <input style="color: #C0C0C0;" value="[email protected]" 
    onfocus="this.value=''; this.style.color='#000000'">

Of course, if your user fills in the field, changes focus and comes back to the field, the field will once again be cleared. If you do it like that, be sure that's what you want. You can make it a one time thing by setting a semaphore, like this:

    <script language = "text/Javascript"> 
    cleared[0] = cleared[1] = cleared[2] = 0; //set a cleared flag for each field
    function clearField(t){                   //declaring the array outside of the
    if(! cleared[t.id]){                      // function makes it static and global
        cleared[t.id] = 1;  // you could use true and false, but that's more typing
        t.value='';         // with more chance of typos
        t.style.color='#000000';
        }
    }
    </script>

Your <input> field then looks like this:

    <input id = 0; style="color: #C0C0C0;" value="[email protected]" 
    onfocus=clearField(this)>

APT command line interface-like yes/no input?

There is a function strtobool in Python's standard library: http://docs.python.org/2/distutils/apiref.html?highlight=distutils.util#distutils.util.strtobool

You can use it to check user's input and transform it to True or False value.

excel VBA run macro automatically whenever a cell is changed

I was creating a form in which the user enters an email address used by another macro to email a specific cell group to the address entered. I patched together this simple code from several sites and my limited knowledge of VBA. This simply watches for one cell (In my case K22) to be updated and then kills any hyperlink in that cell.

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim KeyCells As Range

    ' The variable KeyCells contains the cells that will
    ' cause an alert when they are changed.
    Set KeyCells = Range("K22")

    If Not Application.Intersect(KeyCells, Range(Target.Address)) _
           Is Nothing Then

        Range("K22").Select
        Selection.Hyperlinks.Delete

    End If 
End Sub

How do I check form validity with angularjs?

Example

<div ng-controller="ExampleController">
  <form name="myform">
   Name: <input type="text" ng-model="user.name" /><br>
   Email: <input type="email" ng-model="user.email" /><br>
  </form>
</div>

<script>
  angular.module('formExample', [])
    .controller('ExampleController', ['$scope', function($scope) {

     //if form is not valid then return the form.
     if(!$scope.myform.$valid) {
       return;
     }
  }]);
</script>

Cycles in an Undirected Graph

As others have mentioned... A depth first search will solve it. In general depth first search takes O(V + E) but in this case you know the graph has at most O(V) edges. So you can simply run a DFS and once you see a new edge increase a counter. When the counter has reached V you don't have to continue because the graph has certainly a cycle. Obviously this takes O(v).

Why use the 'ref' keyword when passing an object?

By using the ref keyword with reference types you are effectively passing a reference to the reference. In many ways it's the same as using the out keyword but with the minor difference that there's no guarantee that the method will actually assign anything to the ref'ed parameter.

How to upgrade OpenSSL in CentOS 6.5 / Linux / Unix from source?

The fix for the heartbleed vulnerability has been backported to 1.0.1e-16 by Red Hat for Enterprise Linux see, and this is therefore the official fix that CentOS ships.

Replacing OpenSSL with the latest version from upstream (i.e. 1.0.1g) runs the risk of introducing functionality changes which may break compatibility with applications/clients in unpredictable ways, causes your system to diverge from RHEL, and puts you on the hook for personally maintaining future updates to that package. By replacing openssl using a simple make config && make && make install means that you also lose the ability to use rpm to manage that package and perform queries on it (e.g. verifying all the files are present and haven't been modified or had permissions changed without also updating the RPM database).

I'd also caution that crypto software can be extremely sensitive to seemingly minor things like compiler options, and if you don't know what you're doing, you could introduce vulnerabilities in your local installation.

Save file to specific folder with curl command

This option comes in curl 7.73.0:

curl --create-dirs -O --output-dir /tmp/receipes https://example.com/pancakes.jpg

How to escape double quotes in a title attribute

This variant -

_x000D_
_x000D_
<a title="Some &quot;text&quot;">Hover me</a>
_x000D_
_x000D_
_x000D_

Is correct and it works as expected - you see normal quotes in rendered page.

What does <a href="#" class="view"> mean?

It probably works with Javascript. When you click the link, nothing happens because it points to the current site. The javascript will then load a window or an url. It's used a lot in AJAX web apps.

Convert Decimal to Varchar

Here's one way:

create table #work
(
  something decimal(8,3) not null 
)

insert #work values ( 0 )
insert #work values ( 12345.6789 )
insert #work values ( 3.1415926 )
insert #work values ( 45 )
insert #work values ( 9876.123456 )
insert #work values ( -12.5678 )

select convert(varchar,convert(decimal(8,2),something))
from #work

if you want it right-aligned, something like this should do you:

select str(something,8,2) from #work

How can I compare two strings in java and define which of them is smaller than the other alphabetically?

If you would like to ignore case you could use the following:

String s = "yip";
String best = "yodel";
int compare = s.compareToIgnoreCase(best);
if(compare < 0){
    //-1, --> s is less than best. ( s comes alphabetically first)
}
else if(compare > 0 ){
// best comes alphabetically first.
}
else{
    // strings are equal.
}

How to compile c# in Microsoft's new Visual Studio Code?

Install the extension "Code Runner". Check if you can compile your program with csc (ex.: csc hello.cs). The command csc is shipped with Mono. Then add this to your VS Code user settings:

"code-runner.executorMap": {
        "csharp": "echo '# calling mono\n' && cd $dir && csc /nologo $fileName && mono $dir$fileNameWithoutExt.exe",
        // "csharp": "echo '# calling dotnet run\n' && dotnet run"
    }

Open your C# file and use the execution key of Code Runner.

Edit: also added dotnet run, so you can choose how you want to execute your program: with Mono, or with dotnet. If you choose dotnet, then first create the project (dotnet new console, dotnet restore).

Checking if object is empty, works with ng-show but not from controller?

you can check length of items

ng-show="items.length"

How to load/reference a file as a File instance from the classpath

I find this one-line code as most efficient and useful:

File file = new File(ClassLoader.getSystemResource("com/path/to/file.txt").getFile());

Works like a charm.

C++ equivalent of StringBuffer/StringBuilder?

I wanted to add something new because of the following:

At a first attemp I failed to beat

std::ostringstream 's operator<<

efficiency, but with more attemps I was able to make a StringBuilder that is faster in some cases.

Everytime I append a string I just store a reference to it somewhere and increase the counter of the total size.

The real way I finally implemented it (Horror!) is to use a opaque buffer(std::vector < char > ):

  • 1 byte header (2 bits to tell if following data is :moved string, string or byte[])
  • 6 bits to tell lenght of byte[]

for byte [ ]

  • I store directly bytes of short strings (for sequential memory access)

for moved strings (strings appended with std::move)

  • The pointer to a std::string object (we have ownership)
  • set a flag in the class if there are unused reserved bytes there

for strings

  • The pointer to a std::string object (no ownership)

There's also one small optimization, if last inserted string was mov'd in, it checks for free reserved but unused bytes and store further bytes in there instead of using the opaque buffer (this is to save some memory, it actually make it slightly slower, maybe depend also on the CPU, and it is rare to see strings with extra reserved space anyway)

This was finally slightly faster than std::ostringstream but it has few downsides:

  • I assumed fixed lenght char types (so 1,2 or 4 bytes, not good for UTF8), I'm not saying it will not work for UTF8, Just I don't checked it for laziness.
  • I used bad coding practise (opaque buffer, easy to make it not portable, I believe mine is portable by the way)
  • Lacks all features of ostringstream
  • If some referenced string is deleted before mergin all the strings: undefined behaviour.

conclusion? use std::ostringstream

It already fix the biggest bottleneck while ganing few % points in speed with mine implementation is not worth the downsides.

How to SHA1 hash a string in Android?

You don't need andorid for this. You can just do it in simple java.

Have you tried a simple java example and see if this returns the right sha1.

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class AeSimpleSHA1 {
    private static String convertToHex(byte[] data) {
        StringBuilder buf = new StringBuilder();
        for (byte b : data) {
            int halfbyte = (b >>> 4) & 0x0F;
            int two_halfs = 0;
            do {
                buf.append((0 <= halfbyte) && (halfbyte <= 9) ? (char) ('0' + halfbyte) : (char) ('a' + (halfbyte - 10)));
                halfbyte = b & 0x0F;
            } while (two_halfs++ < 1);
        }
        return buf.toString();
    }

    public static String SHA1(String text) throws NoSuchAlgorithmException, UnsupportedEncodingException {
        MessageDigest md = MessageDigest.getInstance("SHA-1");
        byte[] textBytes = text.getBytes("iso-8859-1");
        md.update(textBytes, 0, textBytes.length);
        byte[] sha1hash = md.digest();
        return convertToHex(sha1hash);
    }
}

Also share what your expected sha1 should be. Maybe ObjectC is doing it wrong.

Detect change to selected date with bootstrap-datepicker

$(document).ready(function(){

$("#dateFrom").datepicker({
    todayBtn:  1,
    autoclose: true,
}).on('changeDate', function (selected) {
    var minDate = new Date(selected.date.valueOf());
    $('#dateTo').datepicker('setStartDate', minDate);
});

$("#dateTo").datepicker({
    todayBtn:  1,
    autoclose: true,}) ;

});

AND/OR in Python?

if input == 'a':
    for char in 'abc':
        if char in some_list:
            some_list.remove(char)

Does JavaScript pass by reference?

Without purisms, I think that the best way to emulate scalar argument by reference in JavaScript is using object, like previous an answer tells.

However, I do a little bit different:

I've made the object assignment inside function call, so one can see the reference parameters near the function call. It increases the source readability.

In function declaration, I put the properties like a comment, for the very same reason: readability.

var r;

funcWithRefScalars(r = {amount:200, message:null} );
console.log(r.amount + " - " + r.message);


function funcWithRefScalars(o) {  // o(amount, message)
  o.amount  *= 1.2;
  o.message = "20% increase";
}

In the above example, null indicates clearly an output reference parameter.

The exit:

240 - 20% Increase

On the client-side, console.log should be replaced by alert.

? ? ?

Another method that can be even more readable:

var amount, message;

funcWithRefScalars(amount = [200], message = [null] );
console.log(amount[0] + " - " + message[0]);

function funcWithRefScalars(amount, message) {  // o(amount, message)
   amount[0]  *= 1.2;
   message[0] = "20% increase";
}

Here you don't even need to create new dummy names, like r above.

New warnings in iOS 9: "all bitcode will be dropped"

This issue has been recently fixed (Nov 2010) by Google, see https://code.google.com/p/analytics-issues/issues/detail?id=671. But be aware that as a good fix it brings more bugs :)

You will also have to follow the initialisation method listed here: https://developers.google.com/analytics/devguides/collection/ios/v2.

The latest instructions are going to give you a headache because it references utilities not included in the pod. Below will fail with the cocoapod

// Configure tracker from GoogleService-Info.plist.
NSError *configureError;
[[GGLContext sharedInstance] configureWithError:&configureError];
NSAssert(!configureError, @"Error configuring Google services: %@", configureError);

How to convert timestamp to datetime in MySQL?

DATE_FORMAT(FROM_UNIXTIME(`orderdate`), '%Y-%m-%d %H:%i:%s') as "Date" FROM `orders`

This is the ultimate solution if the given date is in encoded format like 1300464000

Convert dictionary to bytes and back again python?

This should work:

s=json.dumps(variables)
variables2=json.loads(s)
assert(variables==variables2)

Definitive way to trigger keypress events with jQuery

If you want to trigger the keypress or keydown event then all you have to do is:

var e = jQuery.Event("keydown");
e.which = 50; // # Some key code value
$("input").trigger(e);

How to increase MySQL connections(max_connections)?

If you need to increase MySQL Connections without MySQL restart do like below

mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 100   |
+-----------------+-------+
1 row in set (0.00 sec)

mysql> SET GLOBAL max_connections = 150;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like 'max_connections';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| max_connections | 150   |
+-----------------+-------+
1 row in set (0.00 sec)

These settings will change at MySQL Restart.


For permanent changes add below line in my.cnf and restart MySQL

max_connections = 150

How do you simulate Mouse Click in C#?

An example I found somewhere here in the past. Might be of some help:

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

public class Form1 : Form
{
   [DllImport("user32.dll",CharSet=CharSet.Auto, CallingConvention=CallingConvention.StdCall)]
   public static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint cButtons, uint dwExtraInfo);
   //Mouse actions
   private const int MOUSEEVENTF_LEFTDOWN = 0x02;
   private const int MOUSEEVENTF_LEFTUP = 0x04;
   private const int MOUSEEVENTF_RIGHTDOWN = 0x08;
   private const int MOUSEEVENTF_RIGHTUP = 0x10;

   public Form1()
   {
   }

   public void DoMouseClick()
   {
      //Call the imported function with the cursor's current position
      uint X = (uint)Cursor.Position.X;
      uint Y = (uint)Cursor.Position.Y;
      mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, X, Y, 0, 0);
   }

   //...other code needed for the application
}

How to hide iOS status bar

iOS 9 onwards :

As statusBarHidden method was Deprecated from iOS9 you need to add two values in plist as below :

<key>UIStatusBarHidden</key>
<true/>
<key>UIViewControllerBasedStatusBarAppearance</key>
<false/>

or by User Interface Please refre below image :

enter image description here

As statusBarHidden is Deprecated from iOS9 :

@property(readwrite, nonatomic,getter=isStatusBarHidden) BOOL statusBarHidden NS_DEPRECATED_IOS(2_0, 9_0, "Use -[UIViewController prefersStatusBarHidden]") __TVOS_PROHIBITED;

Sites not accepting wget user agent header

I created a ~/.wgetrc file with the following content (obtained from askapache.com but with a newer user agent, because otherwise it didn’t work always):

header = Accept-Language: en-us,en;q=0.5
header = Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
header = Connection: keep-alive
user_agent = Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:40.0) Gecko/20100101 Firefox/40.0
referer = /
robots = off

Now I’m able to download from most (all?) file-sharing (streaming video) sites.

AES Encryption for an NSString on the iPhone

Since you haven't posted any code, it's difficult to know exactly which problems you're encountering. However, the blog post you link to does seem to work pretty decently... aside from the extra comma in each call to CCCrypt() which caused compile errors.

A later comment on that post includes this adapted code, which works for me, and seems a bit more straightforward. If you include their code for the NSData category, you can write something like this: (Note: The printf() calls are only for demonstrating the state of the data at various points — in a real application, it wouldn't make sense to print such values.)

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    NSString *key = @"my password";
    NSString *secret = @"text to encrypt";

    NSData *plain = [secret dataUsingEncoding:NSUTF8StringEncoding];
    NSData *cipher = [plain AES256EncryptWithKey:key];
    printf("%s\n", [[cipher description] UTF8String]);

    plain = [cipher AES256DecryptWithKey:key];
    printf("%s\n", [[plain description] UTF8String]);
    printf("%s\n", [[[NSString alloc] initWithData:plain encoding:NSUTF8StringEncoding] UTF8String]);

    [pool drain];
    return 0;
}

Given this code, and the fact that encrypted data will not always translate nicely into an NSString, it may be more convenient to write two methods that wrap the functionality you need, in forward and reverse...

- (NSData*) encryptString:(NSString*)plaintext withKey:(NSString*)key {
    return [[plaintext dataUsingEncoding:NSUTF8StringEncoding] AES256EncryptWithKey:key];
}

- (NSString*) decryptData:(NSData*)ciphertext withKey:(NSString*)key {
    return [[[NSString alloc] initWithData:[ciphertext AES256DecryptWithKey:key]
                                  encoding:NSUTF8StringEncoding] autorelease];
}

This definitely works on Snow Leopard, and @Boz reports that CommonCrypto is part of the Core OS on the iPhone. Both 10.4 and 10.5 have /usr/include/CommonCrypto, although 10.5 has a man page for CCCryptor.3cc and 10.4 doesn't, so YMMV.


EDIT: See this follow-up question on using Base64 encoding for representing encrypted data bytes as a string (if desired) using safe, lossless conversions.

How do I deploy Node.js applications as a single executable file?

You could create a git repo and setup a link to the node git repo as a dependency. Then any user who clones the repo could also install node.

#git submodule [--quiet] add [-b branch] [-f|--force]
git submodule add /var/Node-repo.git common

You could easily package a script up to automatically clone the git repo you have hosted somewhere and "install" from one that one script file.

#!/bin/sh
#clone git repo
git clone your-repo.git

Is it possible to CONTINUE a loop from an exception?

For this example you really should just use an outer join.

declare
begin
  FOR attr_rec IN ( 
    select attr 
    from USER_TABLE u 
    left outer join attribute_table a 
    on ( u.USERTYPE = 'X' and a.user_id = u.id ) 
  ) LOOP
    <process records> 
    <if primary key of attribute_table is null 
     then the attribute does not exist for this user.>
  END LOOP;
END;

Most efficient way to concatenate strings?

There are 6 types of string concatenations:

  1. Using the plus (+) symbol.
  2. Using string.Concat().
  3. Using string.Join().
  4. Using string.Format().
  5. Using string.Append().
  6. Using StringBuilder.

In an experiment, it has been proved that string.Concat() is the best way to approach if the words are less than 1000(approximately) and if the words are more than 1000 then StringBuilder should be used.

For more information, check this site.

string.Join() vs string.Concat()

The string.Concat method here is equivalent to the string.Join method invocation with an empty separator. Appending an empty string is fast, but not doing so is even faster, so the string.Concat method would be superior here.

What is the difference between URL parameters and query strings?

The query component is indicated by the first ? in a URI. "Query string" might be a synonym (this term is not used in the URI standard).

Some examples for HTTP URIs with query components:

http://example.com/foo?bar
http://example.com/foo/foo/foo?bar/bar/bar
http://example.com/?bar
http://example.com/?@bar._=???/1:
http://example.com/?bar1=a&bar2=b

(list of allowed characters in the query component)

The "format" of the query component is up to the URI authors. A common convention (but nothing more than a convention, as far as the URI standard is concerned¹) is to use the query component for key-value pairs, aka. parameters, like in the last example above: bar1=a&bar2=b.

Such parameters could also appear in the other URI components, i.e., the path² and the fragment. As far as the URI standard is concerned, it’s up to you which component and which format to use.

Example URI with parameters in the path, the query, and the fragment:

http://example.com/foo;key1=value1?key2=value2#key3=value3

¹ The URI standard says about the query component:

[…] query components are often used to carry identifying information in the form of "key=value" pairs […]

² The URI standard says about the path component:

[…] the semicolon (";") and equals ("=") reserved characters are often used to delimit parameters and parameter values applicable to that segment. The comma (",") reserved character is often used for similar purposes.

What is the difference between cssSelector & Xpath and which is better with respect to performance for cross browser testing?

The debate between cssSelector vs XPath would remain as one of the most subjective debate in the Selenium Community. What we already know so far can be summarized as:

  • People in favor of cssSelector say that it is more readable and faster (especially when running against Internet Explorer).
  • While those in favor of XPath tout it's ability to transverse the page (while cssSelector cannot).
  • Traversing the DOM in older browsers like IE8 does not work with cssSelector but is fine with XPath.
  • XPath can walk up the DOM (e.g. from child to parent), whereas cssSelector can only traverse down the DOM (e.g. from parent to child)
  • However not being able to traverse the DOM with cssSelector in older browsers isn't necessarily a bad thing as it is more of an indicator that your page has poor design and could benefit from some helpful markup.
  • Ben Burton mentions you should use cssSelector because that's how applications are built. This makes the tests easier to write, talk about, and have others help maintain.
  • Adam Goucher says to adopt a more hybrid approach -- focusing first on IDs, then cssSelector, and leveraging XPath only when you need it (e.g. walking up the DOM) and that XPath will always be more powerful for advanced locators.

Dave Haeffner carried out a test on a page with two HTML data tables, one table is written without helpful attributes (ID and Class), and the other with them. I have analyzed the test procedure and the outcome of this experiment in details in the discussion Why should I ever use cssSelector selectors as opposed to XPath for automated testing?. While this experiment demonstrated that each Locator Strategy is reasonably equivalent across browsers, it didn't adequately paint the whole picture for us. Dave Haeffner in the other discussion Css Vs. X Path, Under a Microscope mentioned, in an an end-to-end test there were a lot of other variables at play Sauce startup, Browser start up, and latency to and from the application under test. The unfortunate takeaway from that experiment could be that one driver may be faster than the other (e.g. IE vs Firefox), when in fact, that's wasn't the case at all. To get a real taste of what the performance difference is between cssSelector and XPath, we needed to dig deeper. We did that by running everything from a local machine while using a performance benchmarking utility. We also focused on a specific Selenium action rather than the entire test run, and run things numerous times. I have analyzed the specific test procedure and the outcome of this experiment in details in the discussion cssSelector vs XPath for selenium. But the tests were still missing one aspect i.e. more browser coverage (e.g., Internet Explorer 9 and 10) and testing against a larger and deeper page.

Dave Haeffner in another discussion Css Vs. X Path, Under a Microscope (Part 2) mentions, in order to make sure the required benchmarks are covered in the best possible way we need to consider an example that demonstrates a large and deep page.


Test SetUp

To demonstrate this detailed example, a Windows XP virtual machine was setup and Ruby (1.9.3) was installed. All the available browsers and their equivalent browser drivers for Selenium was also installed. For benchmarking, Ruby's standard lib benchmark was used.


Test Code

require_relative 'base'
require 'benchmark'

class LargeDOM < Base

  LOCATORS = {
    nested_sibling_traversal: {
      css: "div#siblings > div:nth-of-type(1) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3) > div:nth-of-type(3)",
      xpath: "//div[@id='siblings']/div[1]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]/div[3]"
    },
    nested_sibling_traversal_by_class: {
      css: "div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1 > div.item-1",
      xpath: "//div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]/div[contains(@class, 'item-1')]"
    },
    table_header_id_and_class: {
      css: "table#large-table thead .column-50",
      xpath: "//table[@id='large-table']//thead//*[@class='column-50']"
    },
    table_header_id_class_and_direct_desc: {
      css: "table#large-table > thead .column-50",
      xpath: "//table[@id='large-table']/thead//*[@class='column-50']"
    },
    table_header_traversing: {
      css: "table#large-table thead tr th:nth-of-type(50)",
      xpath: "//table[@id='large-table']//thead//tr//th[50]"
    },
    table_header_traversing_and_direct_desc: {
      css: "table#large-table > thead > tr > th:nth-of-type(50)",
      xpath: "//table[@id='large-table']/thead/tr/th[50]"
    },
    table_cell_id_and_class: {
      css: "table#large-table tbody .column-50",
      xpath: "//table[@id='large-table']//tbody//*[@class='column-50']"
    },
    table_cell_id_class_and_direct_desc: {
      css: "table#large-table > tbody .column-50",
      xpath: "//table[@id='large-table']/tbody//*[@class='column-50']"
    },
    table_cell_traversing: {
      css: "table#large-table tbody tr td:nth-of-type(50)",
      xpath: "//table[@id='large-table']//tbody//tr//td[50]"
    },
    table_cell_traversing_and_direct_desc: {
      css: "table#large-table > tbody > tr > td:nth-of-type(50)",
      xpath: "//table[@id='large-table']/tbody/tr/td[50]"
    }
  }

  attr_reader :driver

  def initialize(driver)
    @driver = driver
    visit '/large'
    is_displayed?(id: 'siblings')
    super
  end

  # The benchmarking approach was borrowed from
  # http://rubylearning.com/blog/2013/06/19/how-do-i-benchmark-ruby-code/
  def benchmark
    Benchmark.bmbm(27) do |bm|
      LOCATORS.each do |example, data|
    data.each do |strategy, locator|
      bm.report(example.to_s + " using " + strategy.to_s) do
        begin
          ENV['iterations'].to_i.times do |count|
         find(strategy => locator)
          end
        rescue Selenium::WebDriver::Error::NoSuchElementError => error
          puts "( 0.0 )"
        end
      end
    end
      end
    end
  end

end

Results

NOTE: The output is in seconds, and the results are for the total run time of 100 executions.

In Table Form:

css_xpath_under_microscopev2

In Chart Form:

  • Chrome:

chart-chrome

  • Firefox:

chart-firefox

  • Internet Explorer 8:

chart-ie8

  • Internet Explorer 9:

chart-ie9

  • Internet Explorer 10:

chart-ie10

  • Opera:

chart-opera


Analyzing the Results

  • Chrome and Firefox are clearly tuned for faster cssSelector performance.
  • Internet Explorer 8 is a grab bag of cssSelector that won't work, an out of control XPath traversal that takes ~65 seconds, and a 38 second table traversal with no cssSelector result to compare it against.
  • In IE 9 and 10, XPath is faster overall. In Safari, it's a toss up, except for a couple of slower traversal runs with XPath. And across almost all browsers, the nested sibling traversal and table cell traversal done with XPath are an expensive operation.
  • These shouldn't be that surprising since the locators are brittle and inefficient and we need to avoid them.

Summary

  • Overall there are two circumstances where XPath is markedly slower than cssSelector. But they are easily avoidable.
  • The performance difference is slightly in favor of for non-IE browsers and slightly in favor of for IE browsers.

Trivia

You can perform the bench-marking on your own, using this library where Dave Haeffner wrapped up all the code.

How do you UrlEncode without using System.Web?

System.Net.WebUtility.HtmlDecode

How do I mock an open used in a with statement (using the Mock framework in Python)?

I might be a bit late to the game, but this worked for me when calling open in another module without having to create a new file.

test.py

import unittest
from mock import Mock, patch, mock_open
from MyObj import MyObj

class TestObj(unittest.TestCase):
    open_ = mock_open()
    with patch.object(__builtin__, "open", open_):
        ref = MyObj()
        ref.save("myfile.txt")
    assert open_.call_args_list == [call("myfile.txt", "wb")]

MyObj.py

class MyObj(object):
    def save(self, filename):
        with open(filename, "wb") as f:
            f.write("sample text")

By patching the open function inside the __builtin__ module to my mock_open(), I can mock writing to a file without creating one.

Note: If you are using a module that uses cython, or your program depends on cython in any way, you will need to import cython's __builtin__ module by including import __builtin__ at the top of your file. You will not be able to mock the universal __builtin__ if you are using cython.

How to hide a View programmatically?

You can call view.setVisibility(View.GONE) if you want to remove it from the layout.

Or view.setVisibility(View.INVISIBLE) if you just want to hide it.

From Android Docs:

INVISIBLE

This view is invisible, but it still takes up space for layout purposes. Use with setVisibility(int) and android:visibility.

GONE

This view is invisible, and it doesn't take any space for layout purposes. Use with setVisibility(int) and android:visibility.

What is the difference between "::" "." and "->" in c++

Put very simple :: is the scoping operator, . is the access operator (I forget what the actual name is?), and -> is the dereference arrow.

:: - Scopes a function. That is, it lets the compiler know what class the function lives in and, thus, how to call it. If you are using this operator to call a function, the function is a static function.

. - This allows access to a member function on an already created object. For instance, Foo x; x.bar() calls the method bar() on instantiated object x which has type Foo. You can also use this to access public class variables.

-> - Essentially the same thing as . except this works on pointer types. In essence it dereferences the pointer, than calls .. Using this is equivalent to (*ptr).method()

Text overwrite in visual studio 2010

If you don't have an insert key, and you're using Visual Studio 2019, then double-clicking the OVR text in the bottom right corner does not work. You'll have to use an on-screen keyboard, if you have one of those, or figure out what your insert key is mapped to. For me, on my mac keyboard hooked up to windows 10, it is the 0 key on the keypad.

how do I insert a column at a specific column index in pandas?

df.insert(loc, column_name, value)

This will work if there is no other column with the same name. If a column, with your provided name already exists in the dataframe, it will raise a ValueError.

You can pass an optional parameter allow_duplicates with True value to create a new column with already existing column name.

Here is an example:



    >>> df = pd.DataFrame({'b': [1, 2], 'c': [3,4]})
    >>> df
       b  c
    0  1  3
    1  2  4
    >>> df.insert(0, 'a', -1)
    >>> df
       a  b  c
    0 -1  1  3
    1 -1  2  4
    >>> df.insert(0, 'a', -2)
    Traceback (most recent call last):
      File "", line 1, in 
      File "C:\Python39\lib\site-packages\pandas\core\frame.py", line 3760, in insert
        self._mgr.insert(loc, column, value, allow_duplicates=allow_duplicates)
      File "C:\Python39\lib\site-packages\pandas\core\internals\managers.py", line 1191, in insert
        raise ValueError(f"cannot insert {item}, already exists")
    ValueError: cannot insert a, already exists
    >>> df.insert(0, 'a', -2,  allow_duplicates = True)
    >>> df
       a  a  b  c
    0 -2 -1  1  3
    1 -2 -1  2  4

How to style the UL list to a single line

in bootstrap use .list-inline css class

<ul class="list-inline">
    <li>Coffee</li>
    <li>Tea</li>
    <li>Milk</li>
</ul>

Ref: https://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_ref_txt_list-inline&stacked=h

Mod in Java produces negative numbers

If the modulus is a power of 2 then you can use a bitmask:

int i = -1 & ~-2; // -1 MOD 2 is 1

By comparison the Pascal language provides two operators; REM takes the sign of the numerator (x REM y is x - (x DIV y) * y where x DIV y is TRUNC(x / y)) and MOD requires a positive denominator and returns a positive result.

Empty responseText from XMLHttpRequest

Had a similar problem to yours. What we had to do is use the document.domain solution found here:

Ways to circumvent the same-origin policy

We also needed to change thins on the web service side. Used the "Access-Control-Allow-Origin" header found here:

https://developer.mozilla.org/En/HTTP_access_control

How to adjust gutter in Bootstrap 3 grid system?

You could create a CSS class for this and apply it to your columns. Since the gutter (spacing between columns) is controlled by padding in Bootstrap 3, adjust the padding accordingly:

.col {
  padding-right:7px;
  padding-left:7px;
}

Demo: http://bootply.com/93473

EDIT If you only want the spacing between columns you can select all cols except first and last like this..

.col:not(:first-child,:last-child) {
  padding-right:7px;
  padding-left:7px;
}

Updated Bootply

For Bootstrap 4 see: Remove gutter space for a specific div only

SCCM 2012 application install "Failed" in client Software Center

I'm assuming you figured this out already but:

Technical Reference for Log Files in Configuration Manager

That's a list of client-side logs and what they do. They are located in Windows\CCM\Logs

AppEnforce.log will show you the actual command-line executed and the resulting exit code for each Deployment Type (only for the new style ConfigMgr Applications)

This is my go-to for troubleshooting apps. Haven't really found any other logs that are exceedingly useful.

How can I convert a Word document to PDF?

I agree with posters listing OpenOffice as a high-fidelity import/export facility of word / pdf docs with a Java API and it also works across platforms. OpenOffice import/export filters are pretty powerful and preserve most formatting during conversion to various formats including PDF. Docmosis and JODReports value-add to make life easier than learning the OpenOffice API directly which can be challenging because of the style of the UNO api and the crash-related bugs.

Blur the edges of an image or background image with CSS

I'm not entirely sure what visual end result you're after, but here's an easy way to blur an image's edge: place a div with the image inside another div with the blurred image.

Working example here: http://jsfiddle.net/ZY5hn/1/

Screenshot

HTML:

<div class="placeholder">
     <!-- blurred background image for blurred edge -->
     <div class="bg-image-blur"></div>
     <!-- same image, no blur -->
     <div class="bg-image"></div>
     <!-- content -->
     <div class="content">Blurred Image Edges</div>
</div>

CSS:

.placeholder {
    margin-right: auto;
    margin-left:auto;
    margin-top: 20px;
    width: 200px;
    height: 200px;
    position: relative;
    /* this is the only relevant part for the example */
}
/* both DIVs have the same image */
 .bg-image-blur, .bg-image {
    background-image: url('http://lorempixel.com/200/200/city/9');
    position:absolute;
    top:0;
    left:0;
    width: 100%;
    height:100%;
}
/* blur the background, to make blurred edges that overflow the unblurred image that is on top */
 .bg-image-blur {
    -webkit-filter: blur(20px);
    -moz-filter: blur(20px);
    -o-filter: blur(20px);
    -ms-filter: blur(20px);
    filter: blur(20px);
}
/* I added this DIV in case you need to place content inside */
 .content {
    position: absolute;
    top:0;
    left:0;
    width: 100%;
    height: 100%;
    color: #fff;
    text-shadow: 0 0 3px #000;
    text-align: center;
    font-size: 30px;
}

Notice the blurred effect is using the image, so it changes with the image color.

I hope this helps.

In Typescript, How to check if a string is Numeric

Most of the time the value that we want to check is string or number, so here is function that i use:

const isNumber = (n: string | number): boolean => 
    !isNaN(parseFloat(String(n))) && isFinite(Number(n));

Codesandbox tests.

const willBeTrue = [0.1, '1', '-1', 1, -1, 0, -0, '0', "-0", 2e2, 1e23, 1.1, -0.1, '0.1', '2e2', '1e23', '-0.1', ' 898', '080']

const willBeFalse = ['9BX46B6A', "+''", '', '-0,1', [], '123a', 'a', 'NaN', 1e10000, undefined, null, NaN, Infinity, () => {}]

How do you send a Firebase Notification to all devices via CURL?

One way to do that is to make all your users' devices subscribe to a topic. That way when you target a message to a specific topic, all devices will get it. I think this how the Notifications section in the Firebase console does it.

How can I split a shell command over multiple lines when using an IF statement?

For Windows/WSL/Cygwin etc users:

Make sure that your line endings are standard Unix line feeds, i.e. \n (LF) only.

Using Windows line endings \r\n (CRLF) line endings will break the command line break.


This is because having \ at the end of a line with Windows line ending translates to \ \r \n.
As Mark correctly explains above:

The line-continuation will fail if you have whitespace after the backslash and before the newline.

This includes not just space () or tabs (\t) but also the carriage return (\r).

Simplest way to serve static data from outside the application server in a Java web application

You can do it by putting your images on a fixed path (for example: /var/images, or c:\images), add a setting in your application settings (represented in my example by the Settings.class), and load them like that, in a HttpServlet of yours:

String filename = Settings.getValue("images.path") + request.getParameter("imageName")
FileInputStream fis = new FileInputStream(filename);

int b = 0;
while ((b = fis.read()) != -1) {
        response.getOutputStream().write(b);
}

Or if you want to manipulate the image:

String filename = Settings.getValue("images.path") + request.getParameter("imageName")
File imageFile = new File(filename);
BufferedImage image = ImageIO.read(imageFile);
ImageIO.write(image, "image/png", response.getOutputStream());

then the html code would be <img src="imageServlet?imageName=myimage.png" />

Of course you should think of serving different content types - "image/jpeg", for example based on the file extension. Also you should provide some caching.

In addition you could use this servlet for quality rescaling of your images, by providing width and height parameters as arguments, and using image.getScaledInstance(w, h, Image.SCALE_SMOOTH), considering performance, of course.

Correlation heatmap

  1. Use the 'jet' colormap for a transition between blue and red.
  2. Use pcolor() with the vmin, vmax parameters.

It is detailed in this answer: https://stackoverflow.com/a/3376734/21974

Axios having CORS issue

May help to someone:

I'm sending data from react application to golang server.

Once I change this, w.Header().Set("Access-Control-Allow-Origin", "*"). Error has fixed.

React form submit function:

async handleSubmit(e) {
    e.preventDefault();

    const headers = {
        'Content-Type': 'text/plain'
    };

    await axios.post(
        'http://localhost:3001/login',
        {
            user_name: this.state.user_name,
            password: this.state.password,
        },
        {headers}
        ).then(response => {
            console.log("Success ========>", response);
        })
        .catch(error => {
            console.log("Error ========>", error);
        }
    )
}

Go server got Router,

func main()  {
    router := mux.NewRouter()

    router.HandleFunc("/login", Login.Login).Methods("POST")

    log.Fatal(http.ListenAndServe(":3001", router))
}

Login.go,

func Login(w http.ResponseWriter, r *http.Request)  {

    var user = Models.User{}
    data, err := ioutil.ReadAll(r.Body)

    if err == nil {
        err := json.Unmarshal(data, &user)
        if err == nil {
            user = Postgres.GetUser(user.UserName, user.Password)
            w.Header().Set("Access-Control-Allow-Origin", "*")
            json.NewEncoder(w).Encode(user)
        }
    }
}

How do I change the background color of the ActionBar of an ActionBarActivity using XML?

This is how you can change the color of Action Bar.

import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Build;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;


public class ActivityUtils {

public static void setActionBarColor(AppCompatActivity appCompatActivity, int colorId){
    ActionBar actionBar = appCompatActivity.getSupportActionBar();
    ColorDrawable colorDrawable = new ColorDrawable(getColor(appCompatActivity, colorId));
    actionBar.setBackgroundDrawable(colorDrawable);
}

public static final int getColor(Context context, int id) {
    final int version = Build.VERSION.SDK_INT;
    if (version >= 23) {
        return ContextCompat.getColor(context, id);
    } else {
        return context.getResources().getColor(id);
    }
}
}

From your MainActivity.java change the action bar color like this

    ActivityUtils.setActionBarColor(this, R.color.green_00c1c1);

Read file from line 2 or skip header row

If you want to read multiple CSV files starting from line 2, this works like a charm

for files in csv_file_list:
        with open(files, 'r') as r: 
            next(r)                  #skip headers             
            rr = csv.reader(r)
            for row in rr:
                #do something

(this is part of Parfait's answer to a different question)

How to redirect cin and cout to files?

If your input file is in.txt, you can use freopen to set stdin file as in.txt

freopen("in.txt","r",stdin);

if you want to do the same with your output:

freopen("out.txt","w",stdout);

this will work for std::cin (if using c++), printf, etc...

This will also help you in debugging your code in clion, vscode

Get scroll position using jquery

Older IE and Firefox browsers attach the scrollbar to the documentElement, or what would be the <html> tag in HTML.

All other browsers attach the scrollbar to document.body, or what would be the <body> tag in HTML.

The correct solution would be to check which one to use, depending on browser

var doc = document.documentElement.clientHeight ? document.documentElement : document.body;
var s   = $(doc).scrollTop();

jQuery does make this a little easier, when passing in either window or document jQuery's scrollTop does a similar check and figures it out, so either of these should work cross-browser

var s = $(document).scrollTop();

or

var s = $(window).scrollTop();

jQuery scrollTop() docs

Description: Get the current vertical position of the scroll bar for the first element in the set of matched elements or set the vertical position of the scroll bar for every matched element.


...nothing that works for my div, just the full page

If it's for a DIV, you'd have to target the element that has the scrollbar attached, to get the scrolled amount

$('div').scrollTop();

If you need to get the elements distance from the top of the document, you can also do

$('div').offset().top

Filtering a list of strings based on contents

mylist = ['a', 'ab', 'abc']
assert 'ab' in mylist

how can I display tooltip or item information on mouse over?

Use the title attribute while alt is important for SEO stuff.

How to resolve git's "not something we can merge" error

For posterity: Like AxeEffect said... if you have no typos check to see if you have ridiculous characters in your local branch name, like commas or apostrophes. Exactly that happened to me just now.

Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister

If you look at the chain of exceptions, the problem is

Caused by: org.hibernate.PropertyNotFoundException: Could not find a setter for property salt in class backend.Account

The problem is that the method Account.setSalt() works fine when you create an instance but not when you retrieve an instance from the database. This is because you don't want to create a new salt each time you load an Account.

To fix this, create a method setSalt(long) with visibility private and Hibernate will be able to set the value (just a note, I think it works with Private, but you might need to make it package or protected).

String Comparison in Java

Leading from answers from @Bozho and @aioobe, lexicographic comparisons are similar to the ordering that one might find in a dictionary.

The Java String class provides the .compareTo () method in order to lexicographically compare Strings. It is used like this "apple".compareTo ("banana").

The return of this method is an int which can be interpreted as follows:

  • returns < 0 then the String calling the method is lexicographically first (comes first in a dictionary)
  • returns == 0 then the two strings are lexicographically equivalent
  • returns > 0 then the parameter passed to the compareTo method is lexicographically first.

More specifically, the method provides the first non-zero difference in ASCII values.

Thus "computer".compareTo ("comparison") will return a value of (int) 'u' - (int) 'a' (20). Since this is a positive result, the parameter ("comparison") is lexicographically first.

There is also a variant .compareToIgnoreCase () which will return 0 for "a".compareToIgnoreCase ("A"); for example.

HTML5 Canvas Rotate Image

This is full degree image rotation code. I recommend you to check the below example app in the jsfiddle.

https://jsfiddle.net/casamia743/xqh48gno/

enter image description here

The process flow of this example app is

  1. load Image, calculate boundaryRad
  2. create temporary canvas
  3. move canvas context origin to joint position of the projected rect
  4. rotate canvas context with input degree amount
  5. use canvas.toDataURL method to make image blob
  6. using image blob, create new Image element and render

function init() {
  ...
  image.onload = function() {
     app.boundaryRad = Math.atan(image.width / image.height);
  }
  ...
}



/**
 * NOTE : When source rect is rotated at some rad or degrees, 
 * it's original width and height is no longer usable in the rendered page.
 * So, calculate projected rect size, that each edge are sum of the 
 * width projection and height projection of the original rect.
 */
function calcProjectedRectSizeOfRotatedRect(size, rad) {
  const { width, height } = size;

  const rectProjectedWidth = Math.abs(width * Math.cos(rad)) + Math.abs(height * Math.sin(rad));
  const rectProjectedHeight = Math.abs(width * Math.sin(rad)) + Math.abs(height * Math.cos(rad));

  return { width: rectProjectedWidth, height: rectProjectedHeight };
}

/**
 * @callback rotatedImageCallback
 * @param {DOMString} dataURL - return value of canvas.toDataURL()
 */

/**
 * @param {HTMLImageElement} image 
 * @param {object} angle
 * @property {number} angle.degree 
 * @property {number} angle.rad
 * @param {rotatedImageCallback} cb
 * 
 */
function getRotatedImage(image, angle, cb) {
  const canvas = document.createElement('canvas');
  const { degree, rad: _rad } = angle;

  const rad = _rad || degree * Math.PI / 180 || 0;
  debug('rad', rad);

  const { width, height } = calcProjectedRectSizeOfRotatedRect(
    { width: image.width, height: image.height }, rad
  );
  debug('image size', image.width, image.height);
  debug('projected size', width, height);

  canvas.width = Math.ceil(width);
  canvas.height = Math.ceil(height);

  const ctx = canvas.getContext('2d');
  ctx.save();

  const sin_Height = image.height * Math.abs(Math.sin(rad))
  const cos_Height = image.height * Math.abs(Math.cos(rad))
  const cos_Width = image.width * Math.abs(Math.cos(rad))
  const sin_Width = image.width * Math.abs(Math.sin(rad))

  debug('sin_Height, cos_Width', sin_Height, cos_Width);
  debug('cos_Height, sin_Width', cos_Height, sin_Width);

  let xOrigin, yOrigin;

  if (rad < app.boundaryRad) {
    debug('case1');
    xOrigin = Math.min(sin_Height, cos_Width);
    yOrigin = 0;
  } else if (rad < Math.PI / 2) {
    debug('case2');
    xOrigin = Math.max(sin_Height, cos_Width);
    yOrigin = 0;
  } else if (rad < Math.PI / 2 + app.boundaryRad) {
    debug('case3');
    xOrigin = width;
    yOrigin = Math.min(cos_Height, sin_Width);
  } else if (rad < Math.PI) {
    debug('case4');
    xOrigin = width;
    yOrigin = Math.max(cos_Height, sin_Width);
  } else if (rad < Math.PI + app.boundaryRad) {
    debug('case5');
    xOrigin = Math.max(sin_Height, cos_Width);
    yOrigin = height;
  } else if (rad < Math.PI / 2 * 3) {
    debug('case6');
    xOrigin = Math.min(sin_Height, cos_Width);
    yOrigin = height;
  } else if (rad < Math.PI / 2 * 3 + app.boundaryRad) {
    debug('case7');
    xOrigin = 0;
    yOrigin = Math.max(cos_Height, sin_Width);
  } else if (rad < Math.PI * 2) {
    debug('case8');
    xOrigin = 0;
    yOrigin = Math.min(cos_Height, sin_Width);
  }

  debug('xOrigin, yOrigin', xOrigin, yOrigin)

  ctx.translate(xOrigin, yOrigin)
  ctx.rotate(rad);
  ctx.drawImage(image, 0, 0);
  if (DEBUG) drawMarker(ctx, 'red');

  ctx.restore();

  const dataURL = canvas.toDataURL('image/jpg');

  cb(dataURL);
}

function render() {
    getRotatedImage(app.image, {degree: app.degree}, renderResultImage)
}

SOAP request to WebService with java

A SOAP request is an XML file consisting of the parameters you are sending to the server.

The SOAP response is equally an XML file, but now with everything the service wants to give you.

Basically the WSDL is a XML file that explains the structure of those two XML.


To implement simple SOAP clients in Java, you can use the SAAJ framework (it is shipped with JSE 1.6 and above):

SOAP with Attachments API for Java (SAAJ) is mainly used for dealing directly with SOAP Request/Response messages which happens behind the scenes in any Web Service API. It allows the developers to directly send and receive soap messages instead of using JAX-WS.

See below a working example (run it!) of a SOAP web service call using SAAJ. It calls this web service.

import javax.xml.soap.*;

public class SOAPClientSAAJ {

    // SAAJ - SOAP Client Testing
    public static void main(String args[]) {
        /*
            The example below requests from the Web Service at:
             http://www.webservicex.net/uszip.asmx?op=GetInfoByCity


            To call other WS, change the parameters below, which are:
             - the SOAP Endpoint URL (that is, where the service is responding from)
             - the SOAP Action

            Also change the contents of the method createSoapEnvelope() in this class. It constructs
             the inner part of the SOAP envelope that is actually sent.
         */
        String soapEndpointUrl = "http://www.webservicex.net/uszip.asmx";
        String soapAction = "http://www.webserviceX.NET/GetInfoByCity";

        callSoapWebService(soapEndpointUrl, soapAction);
    }

    private static void createSoapEnvelope(SOAPMessage soapMessage) throws SOAPException {
        SOAPPart soapPart = soapMessage.getSOAPPart();

        String myNamespace = "myNamespace";
        String myNamespaceURI = "http://www.webserviceX.NET";

        // SOAP Envelope
        SOAPEnvelope envelope = soapPart.getEnvelope();
        envelope.addNamespaceDeclaration(myNamespace, myNamespaceURI);

            /*
            Constructed SOAP Request Message:
            <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:myNamespace="http://www.webserviceX.NET">
                <SOAP-ENV:Header/>
                <SOAP-ENV:Body>
                    <myNamespace:GetInfoByCity>
                        <myNamespace:USCity>New York</myNamespace:USCity>
                    </myNamespace:GetInfoByCity>
                </SOAP-ENV:Body>
            </SOAP-ENV:Envelope>
            */

        // SOAP Body
        SOAPBody soapBody = envelope.getBody();
        SOAPElement soapBodyElem = soapBody.addChildElement("GetInfoByCity", myNamespace);
        SOAPElement soapBodyElem1 = soapBodyElem.addChildElement("USCity", myNamespace);
        soapBodyElem1.addTextNode("New York");
    }

    private static void callSoapWebService(String soapEndpointUrl, String soapAction) {
        try {
            // Create SOAP Connection
            SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();
            SOAPConnection soapConnection = soapConnectionFactory.createConnection();

            // Send SOAP Message to SOAP Server
            SOAPMessage soapResponse = soapConnection.call(createSOAPRequest(soapAction), soapEndpointUrl);

            // Print the SOAP Response
            System.out.println("Response SOAP Message:");
            soapResponse.writeTo(System.out);
            System.out.println();

            soapConnection.close();
        } catch (Exception e) {
            System.err.println("\nError occurred while sending SOAP Request to Server!\nMake sure you have the correct endpoint URL and SOAPAction!\n");
            e.printStackTrace();
        }
    }

    private static SOAPMessage createSOAPRequest(String soapAction) throws Exception {
        MessageFactory messageFactory = MessageFactory.newInstance();
        SOAPMessage soapMessage = messageFactory.createMessage();

        createSoapEnvelope(soapMessage);

        MimeHeaders headers = soapMessage.getMimeHeaders();
        headers.addHeader("SOAPAction", soapAction);

        soapMessage.saveChanges();

        /* Print the request message, just for debugging purposes */
        System.out.println("Request SOAP Message:");
        soapMessage.writeTo(System.out);
        System.out.println("\n");

        return soapMessage;
    }

}

Bound method error

This problem happens as a result of calling a method without brackets. Take a look at the example below:

class SomeClass(object):
    def __init__(self):
        print 'I am starting'

    def some_meth(self):
        print 'I am a method()'

x = SomeClass()
''' Not adding the bracket after the method call would result in method bound error '''
print x.some_meth
''' However this is how it should be called and it does solve it '''
x.some_meth()

Python Pandas : pivot table with aggfunc = count unique distinct

This is a good way of counting entries within .pivot_table:

df2.pivot_table(values='X', index=['Y','Z'], columns='X', aggfunc='count')


        X1  X2
Y   Z       
Y1  Z1   1   1
    Z2   1  NaN
Y2  Z3   1  NaN

How to output git log with the first line only?

Does git log --oneline do what you want?

Git Server Like GitHub?

If you need good, easy GIT server than you must try GitBlit. Also i use gitolite but it only server, with GitBlit you get all in one, server, admin, repos. manager ... URL: http://gitblit.com/

Getting DOM node from React child element

this.props.children should either be a ReactElement or an array of ReactElement, but not components.

To get the DOM nodes of the children elements, you need to clone them and assign them a new ref.

render() {
  return (
    <div>
      {React.Children.map(this.props.children, (element, idx) => {
        return React.cloneElement(element, { ref: idx });
      })}
    </div>
  );
}

You can then access the child components via this.refs[childIdx], and retrieve their DOM nodes via ReactDOM.findDOMNode(this.refs[childIdx]).

How to force ViewPager to re-instantiate its items

I have found a solution. It is just a workaround to my problem but currently the only solution.

ViewPager PagerAdapter not updating the View

public int getItemPosition(Object object) {
   return POSITION_NONE;
}

Does anyone know whether this is a bug or not?

Setting the filter to an OpenFileDialog to allow the typical image formats?

Follow this pattern if you browsing for image files:

dialog.Filter =  "Image files (*.jpg, *.jpeg, *.jpe, *.jfif, *.png) | *.jpg; *.jpeg; *.jpe; *.jfif; *.png";

android download pdf from url then open it with a pdf reader

Hi the problem is in FileDownloader class

 urlConnection.setRequestMethod("GET");
    urlConnection.setDoOutput(true);

You need to remove the above two lines and everything will work fine. Please mark the question as answered if it is working as expected.

Latest solution for the same problem is updated Android PDF Write / Read using Android 9 (API level 28)

Attaching the working code with screenshots.

enter image description here

enter image description here

MainActivity.java

package com.example.downloadread;

import java.io.File;
import java.io.IOException;

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.view.Menu;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void download(View v)
    {
        new DownloadFile().execute("http://maven.apache.org/maven-1.x/maven.pdf", "maven.pdf"); 
    }

    public void view(View v)
    {
        File pdfFile = new File(Environment.getExternalStorageDirectory() + "/testthreepdf/" + "maven.pdf");  // -> filename = maven.pdf
        Uri path = Uri.fromFile(pdfFile);
        Intent pdfIntent = new Intent(Intent.ACTION_VIEW);
        pdfIntent.setDataAndType(path, "application/pdf");
        pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

        try{
            startActivity(pdfIntent);
        }catch(ActivityNotFoundException e){
            Toast.makeText(MainActivity.this, "No Application available to view PDF", Toast.LENGTH_SHORT).show();
        }
    }

    private class DownloadFile extends AsyncTask<String, Void, Void>{

        @Override
        protected Void doInBackground(String... strings) {
            String fileUrl = strings[0];   // -> http://maven.apache.org/maven-1.x/maven.pdf
            String fileName = strings[1];  // -> maven.pdf
            String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
            File folder = new File(extStorageDirectory, "testthreepdf");
            folder.mkdir();

            File pdfFile = new File(folder, fileName);

            try{
                pdfFile.createNewFile();
            }catch (IOException e){
                e.printStackTrace();
            }
            FileDownloader.downloadFile(fileUrl, pdfFile);
            return null;
        }
    }


}

FileDownloader.java

package com.example.downloadread;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class FileDownloader {
    private static final int  MEGABYTE = 1024 * 1024;

    public static void downloadFile(String fileUrl, File directory){
        try {

            URL url = new URL(fileUrl);
            HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
            //urlConnection.setRequestMethod("GET");
            //urlConnection.setDoOutput(true);
            urlConnection.connect();

            InputStream inputStream = urlConnection.getInputStream();
            FileOutputStream fileOutputStream = new FileOutputStream(directory);
            int totalSize = urlConnection.getContentLength();

            byte[] buffer = new byte[MEGABYTE];
            int bufferLength = 0;
            while((bufferLength = inputStream.read(buffer))>0 ){
                fileOutputStream.write(buffer, 0, bufferLength);
            }
            fileOutputStream.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.downloadread"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="18" />
    <uses-permission android:name="android.permission.INTERNET"></uses-permission>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
    <uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission>
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.downloadread.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="15dp"
        android:text="download"
        android:onClick="download" />

    <Button
        android:id="@+id/button2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/button1"
        android:layout_marginTop="38dp"
        android:text="view"
        android:onClick="view" />

</RelativeLayout>

Visual Studio SignTool.exe Not Found

The SignTool is available as part of the Windows SDK (which comes with Visual Studio Community 2015). Make sure to select the "ClickOnce Publishing Tools" from the feature list during the installation of Visual Studio 2015 to get the SignTool.

Once Visual Studio is installed you can run the signtool command from the Visual Studio Command Prompt. By default (on Windows 10) the SignTool will be installed at C:\Program Files (x86)\Windows Kits\10\bin\x86\signtool.exe.

ClickOnce Publishing Tools Installation:

enter image description here

SignTool Location:

enter image description here

IF a cell contains a string

SEARCH does not return 0 if there is no match, it returns #VALUE!. So you have to wrap calls to SEARCH with IFERROR.

For example...

=IF(IFERROR(SEARCH("cat", A1), 0), "cat", "none")

or

=IF(IFERROR(SEARCH("cat",A1),0),"cat",IF(IFERROR(SEARCH("22",A1),0),"22","none"))

Here, IFERROR returns the value from SEARCH when it works; the given value of 0 otherwise.

PHP Fatal error: Using $this when not in object context

You are calling a non-static method :

public function foobarfunc() {
    return $this->foo();
}

Using a static-call :

foobar::foobarfunc();

When using a static-call, the function will be called (even if not declared as static), but, as there is no instance of an object, there is no $this.

So :

  • You should not use static calls for non-static methods
  • Your static methods (or statically-called methods) can't use $this, which normally points to the current instance of the class, as there is no class instance when you're using static-calls.


Here, the methods of your class are using the current instance of the class, as they need to access the $foo property of the class.

This means your methods need an instance of the class -- which means they cannot be static.

This means you shouldn't use static calls : you should instanciate the class, and use the object to call the methods, like you did in your last portion of code :

$foobar = new foobar();
$foobar->foobarfunc();


For more informations, don't hesitate to read, in the PHP manual :


Also note that you probably don't need this line in your __construct method :

global $foo;

Using the global keyword will make the $foo variable, declared outside of all functions and classes, visibile from inside that method... And you probably don't have such a $foo variable.

To access the $foo class-property, you only need to use $this->foo, like you did.

Stop Visual Studio from launching a new browser window when starting debug?

In an ASP.Net 5 project this can now be set for each launch profile.

Open the file launchsettings.json under the Startup Project Properties folder and add "launchBrowser": false to the profile you are configuring, such as in:

"profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": false,
      "environmentVariables": {
        "Hosting:Environment": "Development"
      }
    }
}

Registry Key '...' has value '1.7', but '1.6' is required. Java 1.7 is Installed and the Registry is Pointing to it

In the START menu type "regedit" to open the Registry editor

Go to "HKEY_LOCAL_MACHINE" on the left-hand side registry explorer/tree menu

Click "SOFTWARE" within the "HKEY_LOCAL_MACHINE" registries

Click "JavaSoft" within the "SOFTWARE" registries

Click "Java Runtime Environment" within the "JavaSoft" list of registries here you can see different versions of installed java

Click "Java Runtime Environment"- On right hand side you will get 4-5 rows . Please select "CurrentVersion" and right Click( select modify option) Change version to "1.7"

Now the magic has been completed

mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead

Simply put, you need to rewrite all of your database connections and queries.

You are using mysql_* functions which are now deprecated and will be removed from PHP in the future. So you need to start using MySQLi or PDO instead, just as the error notice warned you.

A basic example of using PDO (without error handling):

<?php
$db = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', 'password');
$result = $db->exec("INSERT INTO table(firstname, lastname) VAULES('John', 'Doe')");
$insertId = $db->lastInsertId();
?>

A basic example of using MySQLi (without error handling):

$db = new mysqli($DBServer, $DBUser, $DBPass, $DBName);
$result = $db->query("INSERT INTO table(firstname, lastname) VAULES('John', 'Doe')");

Here's a handy little PDO tutorial to get you started. There are plenty of others, and ones about the PDO alternative, MySQLi.

Close Bootstrap Modal

some times the solution up doesn't work so you d have properly to remove the in class and add the css display:none manually .

$("#modal").removeClass("in");
$("#modal").css("display","none");

Initialise a list to a specific length in Python

In a talk about core containers internals in Python at PyCon 2012, Raymond Hettinger is suggesting to use [None] * n to pre-allocate the length you want.

Slides available as PPT or via Google

The whole slide deck is quite interesting. The presentation is available on YouTube, but it doesn't add much to the slides.

Abort trap 6 error in C

You are writing to memory you do not own:

int board[2][50]; //make an array with 3 columns  (wrong)
                  //(actually makes an array with only two 'columns')
...
for (i=0; i<num3+1; i++)
    board[2][i] = 'O';
          ^

Change this line:

int board[2][50]; //array with 2 columns (legal indices [0-1][0-49])
          ^

To:

int board[3][50]; //array with 3 columns (legal indices [0-2][0-49])
          ^

When creating an array, the value used to initialize: [3] indicates array size.
However, when accessing existing array elements, index values are zero based.

For an array created: int board[3][50];
Legal indices are board[0][0]...board[2][49]

EDIT To address bad output comment and initialization comment

add an additional "\n" for formatting output:

Change:

  ...
  for (k=0; k<50;k++) {
     printf("%d",board[j][k]);
  }
 }

       ...

To:

  ...
  for (k=0; k<50;k++) {
     printf("%d",board[j][k]);
  }
  printf("\n");//at the end of every row, print a new line
}
...  

Initialize board variable:

int board[3][50] = {0};//initialize all elements to zero

( array initialization discussion... )

How to scale a BufferedImage

AffineTransformOp offers the additional flexibility of choosing the interpolation type.

BufferedImage before = getBufferedImage(encoded);
int w = before.getWidth();
int h = before.getHeight();
BufferedImage after = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
AffineTransform at = new AffineTransform();
at.scale(2.0, 2.0);
AffineTransformOp scaleOp = 
   new AffineTransformOp(at, AffineTransformOp.TYPE_BILINEAR);
after = scaleOp.filter(before, after);

The fragment shown illustrates resampling, not cropping; this related answer addresses the issue; some related examples are examined here.

C Programming: How to read the whole file contents into a buffer

Portability between Linux and Windows is a big headache, since Linux is a POSIX-conformant system with - generally - a proper, high quality toolchain for C, whereas Windows doesn't even provide a lot of functions in the C standard library.

However, if you want to stick to the standard, you can write something like this:

#include <stdio.h>
#include <stdlib.h>

FILE *f = fopen("textfile.txt", "rb");
fseek(f, 0, SEEK_END);
long fsize = ftell(f);
fseek(f, 0, SEEK_SET);  /* same as rewind(f); */

char *string = malloc(fsize + 1);
fread(string, 1, fsize, f);
fclose(f);

string[fsize] = 0;

Here string will contain the contents of the text file as a properly 0-terminated C string. This code is just standard C, it's not POSIX-specific (although that it doesn't guarantee it will work/compile on Windows...)

Java OCR implementation

If you are looking for a very extensible option or have a specific problem domain you could consider rolling your own using the Java Object Oriented Neural Engine. Another JOONE reference.

I used it successfully in a personal project to identify the letter from an image such as this, you can find all the source for the OCR component of my application on github, here.

Alternative to deprecated getCellType

    FileInputStream fis = new FileInputStream(new File("C:/Test.xlsx"));

    //create workbook instance
    XSSFWorkbook wb = new XSSFWorkbook(fis);

    //create a sheet object to retrieve the sheet
    XSSFSheet sheet = wb.getSheetAt(0);

    //to evaluate cell type
    FormulaEvaluator formulaEvaluator = wb.getCreationHelper().createFormulaEvaluator();

    for(Row row : sheet)
    {
        for(Cell cell : row)
        {
            switch(formulaEvaluator.evaluateInCell(cell).getCellTypeEnum())
            {
            case NUMERIC:
                System.out.print(cell.getNumericCellValue() + "\t");
                break;
            case STRING:
                System.out.print(cell.getStringCellValue() + "\t");
                break;
            default:
                break;

            }
        }
        System.out.println();
    }

This code will work fine. Use getCellTypeEnum() and to compare use just NUMERIC or STRING.

READ_EXTERNAL_STORAGE permission for Android

You have two solutions for your problem. The quick one is to lower targetApi to 22 (build.gradle file). Second is to use new and wonderful ask-for-permission model:

if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)
        != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?
    if (shouldShowRequestPermissionRationale(
            Manifest.permission.READ_EXTERNAL_STORAGE)) {
        // Explain to the user why we need to read the contacts
    }

    requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
            MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);

    // MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE is an
    // app-defined int constant that should be quite unique

    return;
}

Sniplet found here: https://developer.android.com/training/permissions/requesting.html

Solutions 2: If it does not work try this:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
    && ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
        REQUEST_PERMISSION);

return;

}

and then in callback

@Override
public void onRequestPermissionsResult(final int requestCode, @NonNull final String[] permissions, @NonNull final int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == REQUEST_PERMISSION) {
    if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        // Permission granted.
    } else {
        // User refused to grant permission.
    }
}
}

that is from comments. thanks

What is the relative performance difference of if/else versus switch statement in Java?

It's extremely unlikely that an if/else or a switch is going to be the source of your performance woes. If you're having performance problems, you should do a performance profiling analysis first to determine where the slow spots are. Premature optimization is the root of all evil!

Nevertheless, it's possible to talk about the relative performance of switch vs. if/else with the Java compiler optimizations. First note that in Java, switch statements operate on a very limited domain -- integers. In general, you can view a switch statement as follows:

switch (<condition>) {
   case c_0: ...
   case c_1: ...
   ...
   case c_n: ...
   default: ...
}

where c_0, c_1, ..., and c_N are integral numbers that are targets of the switch statement, and <condition> must resolve to an integer expression.

  • If this set is "dense" -- that is, (max(ci) + 1 - min(ci)) / n > α, where 0 < k < α < 1, where k is larger than some empirical value, a jump table can be generated, which is highly efficient.

  • If this set is not very dense, but n >= β, a binary search tree can find the target in O(2 * log(n)) which is still efficient too.

For all other cases, a switch statement is exactly as efficient as the equivalent series of if/else statements. The precise values of α and β depend on a number of factors and are determined by the compiler's code-optimization module.

Finally, of course, if the domain of <condition> is not the integers, a switch statement is completely useless.

Calculate business days

calculate workdays between two dates including holidays and custom workweek

The answer is not that trivial - thus my suggestion would be to use a class where you can configure more than relying on simplistic function (or assuming a fixed locale and culture). To get the date after a certain number of workdays you'll:

  1. need to specify what weekdays you'll be working (default to MON-FRI) - the class allows you to enable or disable each weekday individually.
  2. need to know that you need to consider public holidays (country and state) to be accurate

Functional Approach

/**
 * @param days, int
 * @param $format, string: dateformat (if format defined OTHERWISE int: timestamp) 
 * @param start, int: timestamp (mktime) default: time() //now
 * @param $wk, bit[]: flags for each workday (0=SUN, 6=SAT) 1=workday, 0=day off
 * @param $holiday, string[]: list of dates, YYYY-MM-DD, MM-DD 
 */
function working_days($days, $format='', $start=null, $week=[0,1,1,1,1,1,0], $holiday=[])
{
    if(is_null($start)) $start = time();
    if($days <= 0) return $start;
    if(count($week) != 7) trigger_error('workweek must contain bit-flags for 7 days');
    if(array_sum($week) == 0) trigger_error('workweek must contain at least one workday');
    $wd = date('w', $start);//0=sun, 6=sat
    $time = $start;
    while($days)
    {
        if(
        $week[$wd]
        && !in_array(date('Y-m-d', $time), $holiday)
        && !in_array(date('m-d', $time), $holiday)
        ) --$days; //decrement on workdays
        $wd = date('w', $time += 86400); //add one day in seconds
    }
    $time -= 86400;//include today
    return $format ? date($format, $time): $time;
}

//simple usage
$ten_days = working_days(10, 'D F d Y');
echo '<br>ten workingdays (MON-FRI) disregarding holidays: ',$ten_days;

//work on saturdays and add new years day as holiday
$ten_days = working_days(10, 'D F d Y', null, [0,1,1,1,1,1,1], ['01-01']);
echo '<br>ten workingdays (MON-SAT) disregarding holidays: ',$ten_days;

Typescript ReferenceError: exports is not defined

  {
    "compileOnSave": false,
    "compilerOptions": {
      "baseUrl": "./",
      "outDir": "./dist",
      "sourceMap": true,
      "declaration": false,
      "module": "esnext",
      "moduleResolution": "node",
      "emitDecoratorMetadata": true,
      "experimentalDecorators": true,
      "target": "es5",
      "typeRoots": ["node_modules/@types"],
      "lib": ["es2018", "dom"]
    }
  }

How to add new DataRow into DataTable?

    GRV.DataSource = Class1.DataTable;
            GRV.DataBind();

Class1.GRV.Rows[e.RowIndex].Delete();
        GRV.DataSource = Class1.DataTable;
        GRV.DataBind();

SyntaxError: cannot assign to operator

in python only work

a=4
b=3

i=a+b

which i is new operator

Best way to serialize/unserialize objects in JavaScript?

I've added yet another JavaScript serializer repo to GitHub.

Rather than take the approach of serializing and deserializing JavaScript objects to an internal format the approach here is to serialize JavaScript objects out to native JavaScript. This has the advantage that the format is totally agnostic from the serializer, and the object can be recreated simply by calling eval().

https://github.com/iconico/JavaScript-Serializer

Remove NA values from a vector

I ran a quick benchmark comparing the two base approaches and it turns out that x[!is.na(x)] is faster than na.omit. User qwr suggested I try purrr::dicard also - this turned out to be massively slower (though I'll happily take comments on my implementation & test!)

microbenchmark::microbenchmark(
  purrr::map(airquality,function(x) {x[!is.na(x)]}), 
  purrr::map(airquality,na.omit),
  purrr::map(airquality, ~purrr::discard(.x, .p = is.na)),
  times = 1e6)

Unit: microseconds
                                                     expr    min     lq      mean median      uq       max neval cld
 purrr::map(airquality, function(x) {     x[!is.na(x)] })   66.8   75.9  130.5643   86.2  131.80  541125.5 1e+06 a  
                          purrr::map(airquality, na.omit)   95.7  107.4  185.5108  129.3  190.50  534795.5 1e+06  b 
  purrr::map(airquality, ~purrr::discard(.x, .p = is.na)) 3391.7 3648.6 5615.8965 4079.7 6486.45 1121975.4 1e+06   c

For reference, here's the original test of x[!is.na(x)] vs na.omit:

microbenchmark::microbenchmark(
    purrr::map(airquality,function(x) {x[!is.na(x)]}), 
    purrr::map(airquality,na.omit), 
    times = 1000000)


Unit: microseconds
                                              expr  min   lq      mean median    uq      max neval cld
 map(airquality, function(x) {     x[!is.na(x)] }) 53.0 56.6  86.48231   58.1  64.8 414195.2 1e+06  a 
                          map(airquality, na.omit) 85.3 90.4 134.49964   92.5 104.9 348352.8 1e+06   b

Java abstract interface

An abstract Interface is not as redundant as everyone seems to be saying, in theory at least.

An Interface can be extended, just as a Class can. If you design an Interface hierarchy for your application you may well have a 'Base' Interface, you extend other Interfaces from but do not want as an Object in itself.

Example:

public abstract interface MyBaseInterface {
    public String getName();
}

public interface MyBoat extends MyBaseInterface {
    public String getMastSize();
}

public interface MyDog extends MyBaseInterface {
    public long tinsOfFoodPerDay();
}

You do not want a Class to implement the MyBaseInterface, only the other two, MMyDog and MyBoat, but both interfaces share the MyBaseInterface interface, so have a 'name' property.

I know its kinda academic, but I thought some might find it interesting. :-)

It is really just a 'marker' in this case, to signal to implementors of the interface it wasn't designed to be implemented on its own. I should point out a compiler (At least the sun/ora 1.6 I tried it with) compiles a class that implements an abstract interface.

JavaScript null check

In your case use data==null (which is true ONLY for null and undefined - on second picture focus on rows/columns null-undefined)

_x000D_
_x000D_
function test(data) {_x000D_
    if (data != null) {_x000D_
        console.log('Data: ', data);_x000D_
    }_x000D_
}_x000D_
_x000D_
test();          // the data=undefined_x000D_
test(null);      // the data=null_x000D_
test(undefined); // the data=undefined_x000D_
_x000D_
test(0); _x000D_
test(false); _x000D_
test('something');
_x000D_
_x000D_
_x000D_

Here you have all (src):

if

enter image description here

== (its negation !=)

enter image description here

=== (its negation !==)

enter image description here

Print a variable in hexadecimal in Python

Use

print " ".join("0x%s"%my_string[i:i+2] for i in range(0, len(my_string), 2))

like this:

>>> my_string = "deadbeef"
>>> print " ".join("0x%s"%my_string[i:i+2] for i in range(0, len(my_string), 2))
0xde 0xad 0xbe 0xef
>>>

On an unrelated side note ... using string as a variable name even as an example variable name is very bad practice.

How can I delete multiple lines in vi?

d5d "cuts" five lines

I usually just throw the number in the middle like:

d7l = delete 7 letters

Uncaught TypeError: Cannot read property 'toLowerCase' of undefined

This Works For me !!!

Call a Function without Parameter

$("#CourseSelect").change(function(e1) {
   loadTeachers();
});

Call a Function with Parameter

$("#CourseSelect").change(function(e1) {
    loadTeachers($(e1.target).val());
});

SQL: capitalize first letter only

Create the below function

Alter FUNCTION InitialCap(@String VARCHAR(8000))
                  RETURNS VARCHAR(8000)
                 AS
 BEGIN 

                   DECLARE @Position INT;

SELECT @String   = STUFF(LOWER(@String),1,1,UPPER(LEFT(@String,1))) COLLATE Latin1_General_Bin,
                    @Position = PATINDEX('%[^A-Za-z''][a-z]%',@String COLLATE Latin1_General_Bin);

                    WHILE @Position > 0
                    SELECT @String   = STUFF(@String,@Position,2,UPPER(SUBSTRING(@String,@Position,2))) COLLATE Latin1_General_Bin,
                    @Position = PATINDEX('%[^A-Za-z''][a-z]%',@String COLLATE Latin1_General_Bin);

                     RETURN @String;
  END ;

Then call it like

select dbo.InitialCap(columnname) from yourtable

How does the stack work in assembly language?

I haven't seen the Gas assembler specifically, but in general the stack is "implemented" by maintaining a reference to the location in memory where the top of the stack resides. The memory location is stored in a register, which has different names for different architectures, but can be thought of as the stack pointer register.

The pop and push commands are implemented in most architectures for you by building upon micro instructions. However, some "Educational Architectures" require you implement them your self. Functionally, push would be implemented somewhat like this:

   load the address in the stack pointer register to a gen. purpose register x
   store data y at the location x
   increment stack pointer register by size of y

Also, some architectures store the last used memory address as the Stack Pointer. Some store the next available address.

How can I zoom an HTML element in Firefox and Opera?

For me this works well with IE10, Chrome, Firefox and Safari:

   #MyDiv>*
   {
        zoom: 50%;
        -moz-transform: scale(0.5);
        -webkit-transform: scale(1.0);
   }

This zooms all content in to 50%.