Programs & Examples On #Send

is a generic tag for communication between programmed elements using some protocol.

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 send HTML email using linux command line

On OS X (10.9.4), cat works, and is easier if your email is already in a file:

cat email_template.html  | mail -s "$(echo -e "Test\nContent-Type: text/html")" [email protected]

websocket.send() parameter

As I understand it, you want the server be able to send messages through from client 1 to client 2. You cannot directly connect two clients because one of the two ends of a WebSocket connection needs to be a server.

This is some pseudocodish JavaScript:

Client:

var websocket = new WebSocket("server address");

websocket.onmessage = function(str) {
  console.log("Someone sent: ", str);
};

// Tell the server this is client 1 (swap for client 2 of course)
websocket.send(JSON.stringify({
  id: "client1"
}));

// Tell the server we want to send something to the other client
websocket.send(JSON.stringify({
  to: "client2",
  data: "foo"
}));

Server:

var clients = {};

server.on("data", function(client, str) {
  var obj = JSON.parse(str);

  if("id" in obj) {
    // New client, add it to the id/client object
    clients[obj.id] = client;
  } else {
    // Send data to the client requested
    clients[obj.to].send(obj.data);
  }
});

How to send value attribute from radio button in PHP

When you select a radio button and click on a submit button, you need to handle the submission of any selected values in your php code using $_POST[]
For example:
if your radio button is:

<input type="radio" name="rdb" value="male"/>

then in your php code you need to use:

$rdb_value = $_POST['rdb'];

Send HTML in email via PHP

Use PHPMailer,

To send HTML mail you have to set $mail->isHTML() only, and you can set your body with HTML tags

Here is a well written tutorial :

rohitashv.wordpress.com/2013/01/19/how-to-send-mail-using-php/

Java's L number (long) specification

To understand why it is necessary to distinguish between int and long literals, consider:

long l = -1 >>> 1;

versus

int a = -1;
long l = a >>> 1;

Now as you would rightly expect, both code fragments give the same value to variable l. Without being able to distinguish int and long literals, what is the interpretation of -1 >>> 1?

-1L >>> 1 // ?

or

(int)-1 >>> 1 // ?

So even if the number is in the common range, we need to specify type. If the default changed with magnitude of the literal, then there would be a weird change in the interpretations of expressions just from changing the digits.

This does not occur for byte, short and char because they are always promoted before performing arithmetic and bitwise operations. Arguably their should be integer type suffixes for use in, say, array initialisation expressions, but there isn't. float uses suffix f and double d. Other literals have unambiguous types, with there being a special type for null.

AngularJS - add HTML element to dom in directive without jQuery

If your destination element is empty and will only contain the <svg> tag you could consider using ng-bind-html as follow :

Declare your HTML tag in the directive scope variable

link: function (scope, iElement, iAttrs) {

    scope.svgTag = '<svg width="600" height="100" class="svg"></svg>';

    ...
}

Then, in your directive template, just add the proper attribute at the exact place you want to append the svg tag :

<!-- start of directive template code -->
...
<!-- end of directive template code -->
<div ng-bind-html="svgTag"></div>

Don't forget to include ngSanitize to allow ng-bind-html to automatically parse the HTML string to trusted HTML and avoid insecure code injection warnings.

See official documentation for more details.

How to call webmethod in Asp.net C#

There are quite a few elements of the $.Ajax() that can cause issues if they are not defined correctly. I would suggest rewritting your javascript in its most basic form, you will most likely find that it works fine.

Script example:

$.ajax({
    type: "POST",
    url: '/Default.aspx/TestMethod',
    data: '{message: "HAI" }',
    contentType: "application/json; charset=utf-8",
    success: function (data) {
        console.log(data);
    },
    failure: function (response) {
        alert(response.d);
    }
});

WebMethod example:

[WebMethod]
public static string TestMethod(string message)
{
     return "The message" + message;
}

Find column whose name contains a specific string

You can also use df.columns[df.columns.str.contains(pat = 'spike')]

data = {'spike-2': [1,2,3], 'hey spke': [4,5,6], 'spiked-in': [7,8,9], 'no': [10,11,12]}
df = pd.DataFrame(data)

colNames = df.columns[df.columns.str.contains(pat = 'spike')] 

print(colNames)

This will output the column names: 'spike-2', 'spiked-in'

More about pandas.Series.str.contains.

Apply function to each column in a data frame observing each columns existing data type

The best way to do this is avoid base *apply functions, which coerces the entire data frame to an array, possibly losing information.

If you wanted to apply a function as.numeric to every column, a simple way is using mutate_all from dplyr:

t %>% mutate_all(as.numeric)

Alternatively use colwise from plyr, which will "turn a function that operates on a vector into a function that operates column-wise on a data.frame."

t %>% (colwise(as.numeric))

In the special case of reading in a data table of character vectors and coercing columns into the correct data type, use type.convert or type_convert from readr.


Less interesting answer: we can apply on each column with a for-loop:

for (i in 1:nrow(t)) { t[, i] <- parse_guess(t[, i]) }

I don't know of a good way of doing assignment with *apply while preserving data frame structure.

Changing Node.js listening port

I usually manually set the port that I am listening on in the app.js file (assuming you are using express.js

var server = app.listen(8080, function() {
    console.log('Ready on port %d', server.address().port);
});

This will log Ready on port 8080 to your console.

How to print to console when using Qt

I found this most useful:

#include <QTextStream>

QTextStream out(stdout);
foreach(QString x, strings)
    out << x << endl;

Autoresize View When SubViews are Added

Yes, it is because you are using auto layout. Setting the view frame and resizing mask will not work.

You should read Working with Auto Layout Programmatically and Visual Format Language.

You will need to get the current constraints, add the text field, adjust the contraints for the text field, then add the correct constraints on the text field.

How do I analyze a program's core dump file with GDB when it has command-line parameters?

From RMS's GDB debugger tutorial:

prompt > myprogram
Segmentation fault (core dumped)
prompt > gdb myprogram
...
(gdb) core core.pid
...

Make sure your file really is a core image -- check it using file.

Python - Get path of root project structure

I've recently been trying to do something similar and I have found these answers inadequate for my use cases (a distributed library that needs to detect project root). Mainly I've been battling different environments and platforms, and still haven't found something perfectly universal.

Code local to project

I've seen this example mentioned and used in a few places, Django, etc.

import os
print(os.path.dirname(os.path.abspath(__file__)))

Simple as this is, it only works when the file that the snippet is in is actually part of the project. We do not retrieve the project directory, but instead the snippet's directory

Similarly, the sys.modules approach breaks down when called from outside the entrypoint of the application, specifically I've observed a child thread cannot determine this without relation back to the 'main' module. I've explicitly put the import inside a function to demonstrate an import from a child thread, moving it to top level of app.py would fix it.

app/
|-- config
|   `-- __init__.py
|   `-- settings.py
`-- app.py

app.py

#!/usr/bin/env python
import threading


def background_setup():
    # Explicitly importing this from the context of the child thread
    from config import settings
    print(settings.ROOT_DIR)


# Spawn a thread to background preparation tasks
t = threading.Thread(target=background_setup)
t.start()

# Do other things during initialization

t.join()

# Ready to take traffic

settings.py

import os
import sys


ROOT_DIR = None


def setup():
    global ROOT_DIR
    ROOT_DIR = os.path.dirname(sys.modules['__main__'].__file__)
    # Do something slow

Running this program produces an attribute error:

>>> import main
>>> Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Python2714\lib\threading.py", line 801, in __bootstrap_inner
    self.run()
  File "C:\Python2714\lib\threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "main.py", line 6, in background_setup
    from config import settings
  File "config\settings.py", line 34, in <module>
    ROOT_DIR = get_root()
  File "config\settings.py", line 31, in get_root
    return os.path.dirname(sys.modules['__main__'].__file__)
AttributeError: 'module' object has no attribute '__file__'

...hence a threading-based solution

Location independent

Using the same application structure as before but modifying settings.py

import os
import sys
import inspect
import platform
import threading


ROOT_DIR = None


def setup():
    main_id = None
    for t in threading.enumerate():
        if t.name == 'MainThread':
            main_id = t.ident
            break

    if not main_id:
        raise RuntimeError("Main thread exited before execution")

    current_main_frame = sys._current_frames()[main_id]
    base_frame = inspect.getouterframes(current_main_frame)[-1]

    if platform.system() == 'Windows':
        filename = base_frame.filename
    else:
        filename = base_frame[0].f_code.co_filename

    global ROOT_DIR
    ROOT_DIR = os.path.dirname(os.path.abspath(filename))

Breaking this down: First we want to accurately find the thread ID of the main thread. In Python3.4+ the threading library has threading.main_thread() however, everybody doesn't use 3.4+ so we search through all threads looking for the main thread save it's ID. If the main thread has already exited, it won't be listed in the threading.enumerate(). We raise a RuntimeError() in this case until I find a better solution.

main_id = None
for t in threading.enumerate():
    if t.name == 'MainThread':
        main_id = t.ident
        break

if not main_id:
    raise RuntimeError("Main thread exited before execution")

Next we find the very first stack frame of the main thread. Using the cPython specific function sys._current_frames() we get a dictionary of every thread's current stack frame. Then utilizing inspect.getouterframes() we can retrieve the entire stack for the main thread and the very first frame. current_main_frame = sys._current_frames()[main_id] base_frame = inspect.getouterframes(current_main_frame)[-1] Finally, the differences between Windows and Linux implementations of inspect.getouterframes() need to be handled. Using the cleaned up filename, os.path.abspath() and os.path.dirname() clean things up.

if platform.system() == 'Windows':
    filename = base_frame.filename
else:
    filename = base_frame[0].f_code.co_filename

global ROOT_DIR
ROOT_DIR = os.path.dirname(os.path.abspath(filename))

So far I've tested this on Python2.7 and 3.6 on Windows as well as Python3.4 on WSL

How to do an update + join in PostgreSQL?

Here we go:

update vehicles_vehicle v
set price=s.price_per_vehicle
from shipments_shipment s
where v.shipment_id=s.id;

Simple as I could make it. Thanks guys!

Can also do this:

-- Doesn't work apparently
update vehicles_vehicle 
set price=s.price_per_vehicle
from vehicles_vehicle v
join shipments_shipment s on v.shipment_id=s.id;

But then you've got the vehicle table in there twice, and you're only allowed to alias it once, and you can't use the alias in the "set" portion.

How can I beautify JSON programmatically?

Here's something that might be interesting for developers hacking (minified or obfuscated) JavaScript more frequently.

You can build your own CLI JavaScript beautifier in under 5 mins and have it handy on the command-line. You'll need Mozilla Rhino, JavaScript file of some of the JS beautifiers available online, small hack and a script file to wrap it all up.

I wrote an article explaining the procedure: Command-line JavaScript beautifier implemented in JavaScript.

What happens to C# Dictionary<int, int> lookup if the key does not exist?

int result= YourDictionaryName.TryGetValue(key, out int value) ? YourDictionaryName[key] : 0;

If the key is present in the dictionary, it returns the value of the key otherwise it returns 0.

Hope, this code helps you.

Uncaught TypeError: Cannot set property 'onclick' of null

Make sure your javascript is being executed after your element(s) have loaded, perhaps try putting the js file call just before the tag or use the defer attribute in your script, like so: <script src="app.js" defer></script> this makes sure that your script will be executed after the dom has loaded.

multiple ways of calling parent method in php

Unless I am misunderstanding the question, I would almost always use $this->get_species because the subclass (in this case dog) could overwrite that method since it does extend it. If the class dog doesn't redefine the method then both ways are functionally equivalent but if at some point in the future you decide you want the get_species method in dog should print "dog" then you would have to go back through all the code and change it.

When you use $this it is actually part of the object which you created and so will always be the most up-to-date as well (if the property being used has changed somehow in the lifetime of the object) whereas using the parent class is calling the static class method.

CSS Selector "(A or B) and C"?

Not yet, but there is the experimental :matches() pseudo-class function that does just that:

:matches(.a .b) .c {
  /* stuff goes here */
}

You can find more info on it here and here. Currently, most browsers support its initial version :any(), which works the same way, but will be replaced by :matches(). We just have to wait a little more before using this everywhere (I surely will).

How to change icon on Google map marker

You have to add the targeted map :

var markers = [
            {
            "title": 'This is title',
            "lat": '-37.801578',
            "lng": '145.060508',
            "map":  map,
            "icon": 'http://google-maps-icons.googlecode.com/files/sailboat-tourism.png',
            "description": 'Vikash Rathee. <strong> This is test Description</strong> <br/><a href="http://www.pricingindia.in/pincode.aspx">Pin Code by 

City</a>'
            }
];

java.net.URL read stream to byte[]

I am very surprised that nobody here has mentioned the problem of connection and read timeout. It could happen (especially on Android and/or with some crappy network connectivity) that the request will hang and wait forever.

The following code (which also uses Apache IO Commons) takes this into account, and waits max. 5 seconds until it fails:

public static byte[] downloadFile(URL url)
{
    try {
        URLConnection conn = url.openConnection();
        conn.setConnectTimeout(5000);
        conn.setReadTimeout(5000);
        conn.connect(); 

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        IOUtils.copy(conn.getInputStream(), baos);

        return baos.toByteArray();
    }
    catch (IOException e)
    {
        // Log error and return null, some default or throw a runtime exception
    }
}

How to send email using simple SMTP commands via Gmail?

Unfortunately as I am forced to use a windows server I have been unable to get openssl working in the way the above answer suggests.

However I was able to get a similar program called stunnel (which can be downloaded from here) to work. I got the idea from www.tech-and-dev.com but I had to change the instructions slightly. Here is what I did:

  1. Install telnet client on the windows box.
  2. Download stunnel. (I downloaded and installed a file called stunnel-4.56-installer.exe).
  3. Once installed you then needed to locate the stunnel.conf config file, which in my case I installed to C:\Program Files (x86)\stunnel
  4. Then, you need to open this file in a text viewer such as notepad. Look for [gmail-smtp] and remove the semicolon on the client line below (in the stunnel.conf file, every line that starts with a semicolon is a comment). You should end up with something like:

    [gmail-smtp]
    client = yes
    accept = 127.0.0.1:25
    connect = smtp.gmail.com:465
    

    Once you have done this save the stunnel.conf file and reload the config (to do this use the stunnel GUI program, and click on configuration=>Reload).

Now you should be ready to send email in the windows telnet client!
Go to Start=>run=>cmd.

Once cmd is open type in the following and press Enter:

telnet localhost 25

You should then see something similar to the following:

220 mx.google.com ESMTP f14sm1400408wbe.2

You will then need to reply by typing the following and pressing enter:

helo google

This should give you the following response:

250 mx.google.com at your service

If you get this you then need to type the following and press enter:

ehlo google

This should then give you the following response:

250-mx.google.com at your service, [212.28.228.49]
250-SIZE 35651584
250-8BITMIME
250-AUTH LOGIN PLAIN XOAUTH
250 ENHANCEDSTATUSCODES

Now you should be ready to authenticate with your Gmail details. To do this type the following and press enter:

AUTH LOGIN

This should then give you the following response:

334 VXNlcm5hbWU6

This means that we are ready to authenticate by using our gmail address and password.

However since this is an encrypted session, we're going to have to send the email and password encoded in base64. To encode your email and password, you can use a converter program or an online website to encode it (for example base64 or search on google for ’base64 online encoding’). I reccomend you do not touch the cmd/telnet session again until you have done this.

For example [email protected] would become dGVzdEBnbWFpbC5jb20= and password would become cGFzc3dvcmQ=

Once you have done this copy and paste your converted base64 username into the cmd/telnet session and press enter. This should give you following response:

334 UGFzc3dvcmQ6

Now copy and paste your converted base64 password into the cmd/telnet session and press enter. This should give you following response if both login credentials are correct:

235 2.7.0 Accepted

You should now enter the sender email (should be the same as the username) in the following format and press enter:

MAIL FROM:<[email protected]>

This should give you the following response:

250 2.1.0 OK x23sm1104292weq.10

You can now enter the recipient email address in a similar format and press enter:

RCPT TO:<[email protected]>

This should give you the following response:

250 2.1.5 OK x23sm1104292weq.10

Now you will need to type the following and press enter:

DATA

Which should give you the following response:

354  Go ahead x23sm1104292weq.10

Now we can start to compose the message! To do this enter your message in the following format (Tip: do this in notepad and copy the entire message into the cmd/telnet session):

From: Test <[email protected]>
To: Me <[email protected]>
Subject: Testing email from telnet
This is the body

Adding more lines to the body message.

When you have finished the email enter a dot:

.

This should give you the following response:

250 2.0.0 OK 1288307376 x23sm1104292weq.10

And now you need to end your session by typing the following and pressing enter:

QUIT

This should give you the following response:

221 2.0.0 closing connection x23sm1104292weq.10
Connection to host lost.

And your email should now be in the recipient’s mailbox!

Service located in another namespace

You can achieve this by deploying something at a higher layer than namespaced Services, like the service loadbalancer https://github.com/kubernetes/contrib/tree/master/service-loadbalancer. If you want to restrict it to a single namespace, use "--namespace=ns" argument (it defaults to all namespaces: https://github.com/kubernetes/contrib/blob/master/service-loadbalancer/service_loadbalancer.go#L715). This works well for L7, but is a little messy for L4.

Is there a performance difference between CTE , Sub-Query, Temporary Table or Table Variable?

Just 2 things I think make it ALWAYS preferable to use a # Temp Table rather then a CTE are:

  1. You can not put a primary key on a CTE so the data being accessed by the CTE will have to traverse each one of the indexes in the CTE's tables rather then just accessing the PK or Index on the temp table.

  2. Because you can not add constraints, indexes and primary keys to a CTE they are more prone to bugs creeping in and bad data.


-onedaywhen yesterday

Here is an example where #table constraints can prevent bad data which is not the case in CTE's

DECLARE @BadData TABLE ( 
                       ThisID int
                     , ThatID int );
INSERT INTO @BadData
       ( ThisID
       , ThatID
       ) 
VALUES
       ( 1, 1 ),
       ( 1, 2 ),
       ( 2, 2 ),
       ( 1, 1 );

IF OBJECT_ID('tempdb..#This') IS NOT NULL
    DROP TABLE #This;
CREATE TABLE #This ( 
             ThisID int NOT NULL
           , ThatID int NOT NULL
                        UNIQUE(ThisID, ThatID) );
INSERT INTO #This
SELECT * FROM @BadData;
WITH This_CTE
     AS (SELECT *
           FROM @BadData)
     SELECT *
       FROM This_CTE;

Mocking Extension Methods with Moq

You can't "directly" mock static method (hence extension method) with mocking framework. You can try Moles (http://research.microsoft.com/en-us/projects/pex/downloads.aspx), a free tool from Microsoft that implements a different approach. Here is the description of the tool:

Moles is a lightweight framework for test stubs and detours in .NET that is based on delegates.

Moles may be used to detour any .NET method, including non-virtual/static methods in sealed types.

You can use Moles with any testing framework (it's independent about that).

React js change child component's state from parent component

The state should be managed in the parent component. You can transfer the open value to the child component by adding a property.

class ParentComponent extends Component {
   constructor(props) {
      super(props);
      this.state = {
        open: false
      };

      this.toggleChildMenu = this.toggleChildMenu.bind(this);
   }

   toggleChildMenu() {
      this.setState(state => ({
        open: !state.open
      }));
   }

   render() {
      return (
         <div>
           <button onClick={this.toggleChildMenu}>
              Toggle Menu from Parent
           </button>
           <ChildComponent open={this.state.open} />
         </div>
       );
    }
}

class ChildComponent extends Component {
    render() {
      return (
         <Drawer open={this.props.open}/>
      );
    }
}

Find p-value (significance) in scikit-learn LinearRegression

p_value is among f statistics. if you want to get the value, simply use this few lines of code:

import statsmodels.api as sm
from scipy import stats

diabetes = datasets.load_diabetes()
X = diabetes.data
y = diabetes.target

X2 = sm.add_constant(X)
est = sm.OLS(y, X2)
print(est.fit().f_pvalue)

Should I use pt or px?

px ? Pixels

All of these answers seem to be incorrect. Contrary to intuition, in CSS the px is not pixels. At least, not in the simple physical sense.

Read this article from the W3C, EM, PX, PT, CM, IN…, about how px is a "magical" unit invented for CSS. The meaning of px varies by hardware and resolution. (That article is fresh, last updated 2014-10.)

My own way of thinking about it: 1 px is the size of a thin line intended by a designer to be barely visible.

To quote that article:

The px unit is the magic unit of CSS. It is not related to the current font and also not related to the absolute units. The px unit is defined to be small but visible, and such that a horizontal 1px wide line can be displayed with sharp edges (no anti-aliasing). What is sharp, small and visible depends on the device and the way it is used: do you hold it close to your eyes, like a mobile phone, at arms length, like a computer monitor, or somewhere in between, like a book? The px is thus not defined as a constant length, but as something that depends on the type of device and its typical use.

To get an idea of the appearance of a px, imagine a CRT computer monitor from the 1990s: the smallest dot it can display measures about 1/100th of an inch (0.25mm) or a little more. The px unit got its name from those screen pixels.

Nowadays there are devices that could in principle display smaller sharp dots (although you might need a magnifier to see them). But documents from the last century that used px in CSS still look the same, no matter what the device. Printers, especially, can display sharp lines with much smaller details than 1px, but even on printers, a 1px line looks very much the same as it would look on a computer monitor. Devices change, but the px always has the same visual appearance.

That article gives some guidance about using pt vs px vs em, to answer this Question.

Get distance between two points in canvas

i tend to use this calculation a lot in things i make, so i like to add it to the Math object:

Math.dist=function(x1,y1,x2,y2){ 
  if(!x2) x2=0; 
  if(!y2) y2=0;
  return Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1)); 
}
Math.dist(0,0, 3,4); //the output will be 5
Math.dist(1,1, 4,5); //the output will be 5
Math.dist(3,4); //the output will be 5

Update:

this approach is especially happy making when you end up in situations something akin to this (i often do):

varName.dist=Math.sqrt( ( (varName.paramX-varX)/2-cx )*( (varName.paramX-varX)/2-cx ) + ( (varName.paramY-varY)/2-cy )*( (varName.paramY-varY)/2-cy ) );

that horrid thing becomes the much more manageable:

varName.dist=Math.dist((varName.paramX-varX)/2, (varName.paramY-varY)/2, cx, cy);

Allow only numbers to be typed in a textbox

You also can use some HTML5 attributes, some browsers might already take advantage of them (type="number" min="0").

Whatever you do, remember to re-check your inputs on the server side: you can never assume the client-side validation has been performed.

jQuery UI Slider (setting programmatically)

Here is working version:

var newVal = 10;
var slider = $('#slider');        
var s = $(slider);
$(slider).val(newVal);
$(slider).slider('refresh');

Is there a way to create key-value pairs in Bash script?

In bash version 4 associative arrays were introduced.

declare -A arr

arr["key1"]=val1

arr+=( ["key2"]=val2 ["key3"]=val3 )

The arr array now contains the three key value pairs. Bash is fairly limited what you can do with them though, no sorting or popping etc.

for key in ${!arr[@]}; do
    echo ${key} ${arr[${key}]}
done

Will loop over all key values and echo them out.

Note: Bash 4 does not come with Mac OS X because of its GPLv3 license; you have to download and install it. For more on that see here

How to set Default Controller in asp.net MVC 4 & MVC 5

the best way is to change your route. The default route (defined in your App_Start) sets /Home/Index

routes.MapRoute(
        "Default", // Route name
        "{controller}/{action}/{id}", // URL with parameters*
        new { controller = "Home", action = "Index", 
        id = UrlParameter.Optional }
);

as the default landing page. You can change that to be any route you wish.

routes.MapRoute(
        "Default", // Route name
        "{controller}/{action}/{id}", // URL with parameters*
        new { controller = "Sales", action = "ProjectionReport", 
        id = UrlParameter.Optional }
);

How do I open a new window using jQuery?

It's not really something you need jQuery to do. There is a very simple plain old javascript method for doing this:

window.open('http://www.google.com','GoogleWindow', 'width=800, height=600');

That's it.

The first arg is the url, the second is the name of the window, this should be specified because IE will throw a fit about trying to use window.opener later if there was no window name specified (just a little FYI), and the last two params are width/height.

EDIT: Full specification can be found in the link mmmshuddup provided.

How to convert a Title to a URL slug in jQuery?

Combining a variety of elements from the answers here with normalize provides good coverage. Keep the order of operations to incrementally clean the url.

function clean_url(s) {
    return s.toString().normalize('NFD').replace(/[\u0300-\u036f]/g, "") //remove diacritics
            .toLowerCase()
            .replace(/\s+/g, '-') //spaces to dashes
            .replace(/&/g, '-and-') //ampersand to and
            .replace(/[^\w\-]+/g, '') //remove non-words
            .replace(/\-\-+/g, '-') //collapse multiple dashes
            .replace(/^-+/, '') //trim starting dash
            .replace(/-+$/, ''); //trim ending dash
}

normlize('NFD') breaks accented characters into their components, which are basic letters plus diacritics (the accent part). replace(/[\u0300-\u036f]/g, "") purges all the diacritics, leaving the basic letters by themselves. The rest is explained with inline comments.

How do I make bootstrap table rows clickable?

I show you my example with modal windows...you create your modal and give it an id then In your table you have tr section, just ad the first line you see below (don't forget to set the on the first row like this

<tr onclick="input" data-toggle="modal" href="#the name for my modal windows" >
 <td><label>Some value here</label></td>
</tr>                                                                                                                                                                                   

MessageBodyWriter not found for media type=application/json

I was in the same situation where
- I was not using Maven or Ant,
- I finished this Vogella tutorial on Jersey,
- and I was getting the MessageBodyWriter error when trying to use @Produces(MediaType.APPLICATION_JSON).

This answer by @peeskillet solves the problem - you have to use the Jackson *.jar files that are available from the FasterXML Jackson Download page. You'll need the core files as well as the jaxrs files.

I added them to my WebContent/WEB-INF/lib folder where I have my Jersey *.jar files per the above tutorial, and made the small change to the web.xml file below (again, as originally shared by @peeskillet):

<param-name>jersey.config.server.provider.packages</param-name>
<param-value>
    your.other.package.here, com.fasterxml.jackson.jaxrs.json 
</param-value>

The important part being com.fasterxml.jackson.jaxrs.json.

PHP Connection failed: SQLSTATE[HY000] [2002] Connection refused

For everyone if you still strugle with Refusing connection, here is my advice. Download XAMPP or other similar sw and just start MySQL. You dont have to run apache or other things just the MySQL.

Git is not working after macOS Update (xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools)

I got some errors that the software was unavailable from the update server when trying

xcode-select --install

What fixed it for me was going here https://developer.apple.com/download/more/ and downloading Command Line Tools (macOS 10.14) for Xcode 10 and then installing it manually.

After that, the errors should be gone when you open up a new terminal.

Add error bars to show standard deviation on a plot in R

A solution with ggplot2 :

qplot(x,y)+geom_errorbar(aes(x=x, ymin=y-sd, ymax=y+sd), width=0.25)

enter image description here

How To Define a JPA Repository Query with a Join

You are experiencing this issue for two reasons.

  • The JPQL Query is not valid.
  • You have not created an association between your entities that the underlying JPQL query can utilize.

When performing a join in JPQL you must ensure that an underlying association between the entities attempting to be joined exists. In your example, you are missing an association between the User and Area entities. In order to create this association we must add an Area field within the User class and establish the appropriate JPA Mapping. I have attached the source for User below. (Please note I moved the mappings to the fields)

User.java

@Entity
@Table(name="user")
public class User {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="iduser")
    private Long idUser;

    @Column(name="user_name")
    private String userName;

    @OneToOne()
    @JoinColumn(name="idarea")
    private Area area;

    public Long getIdUser() {
        return idUser;
    }

    public void setIdUser(Long idUser) {
        this.idUser = idUser;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Area getArea() {
        return area;
    }

    public void setArea(Area area) {
        this.area = area;
    }
}

Once this relationship is established you can reference the area object in your @Query declaration. The query specified in your @Query annotation must follow proper syntax, which means you should omit the on clause. See the following:

@Query("select u.userName from User u inner join u.area ar where ar.idArea = :idArea")

While looking over your question I also made the relationship between the User and Area entities bidirectional. Here is the source for the Area entity to establish the bidirectional relationship.

Area.java

@Entity
@Table(name = "area")
public class Area {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="idarea")
    private Long idArea;

    @Column(name="area_name")
    private String areaName;

    @OneToOne(fetch=FetchType.LAZY, mappedBy="area")
    private User user;

    public Long getIdArea() {
        return idArea;
    }

    public void setIdArea(Long idArea) {
        this.idArea = idArea;
    }

    public String getAreaName() {
        return areaName;
    }

    public void setAreaName(String areaName) {
        this.areaName = areaName;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }
}

MySQL error code: 1175 during UPDATE in MySQL Workbench

  1. Preferences...
  2. "Safe Updates"...
  3. Restart server

Preferences...

Safe Updates Restart server

How do I change the background of a Frame in Tkinter?

You use ttk.Frame, bg option does not work for it. You should create style and apply it to the frame.

from tkinter import *
from tkinter.ttk import * 

root = Tk()

s = Style()
s.configure('My.TFrame', background='red')

mail1 = Frame(root, style='My.TFrame')
mail1.place(height=70, width=400, x=83, y=109)
mail1.config()
root.mainloop()

How to get the difference (only additions) between two files in linux

A similar approach to https://stackoverflow.com/a/15385080/337172 but hopefully more understandable and easy to tweak:

diff \
  --new-line-format="%L" \
  --old-line-format="" \
  --unchanged-line-format="" \
  A1 A2

Declaring variables in Excel Cells

You can name cells. This is done by clicking the Name Box (that thing next to the formula bar which says "A1" for example) and typing a name, such as, "myvar". Now you can use that name instead of the cell reference:

= myvar*25

PermissionError: [WinError 5] Access is denied python using moviepy to write gif

Sometimes it occurs when some installations are not completed correctly, the process is stuck, or a file is still opened. So, when you try to run the installation again and the installation requires deleting, you can see the aforementioned error. In my case, shutting down the python processes and command prompt utilization helped.

How to store date/time and timestamps in UTC time zone with JPA and Hibernate

To the best of my knowledge, you need to put your entire Java app in UTC timezone (so that Hibernate will store dates in UTC), and you'll need to convert to whatever timezone desired when you display stuff (at least we do it this way).

At startup, we do:

TimeZone.setDefault(TimeZone.getTimeZone("Etc/UTC"));

And set the desired timezone to the DateFormat:

fmt.setTimeZone(TimeZone.getTimeZone("Europe/Budapest"))

How to remove numbers from a string?

Just want to add since it might be of interest to someone, that you may think about the problem the other way as well. I am not sure if that is of interest here, but I find it relevant.

What I mean by the other way is to say "strip anything that aren't what I am looking for, i.e. if you only want the 'ding' you could say:

var strippedText = ("1 ding ?").replace(/[^a-zA-Z]/g, '');

Which basically mean "remove anything which is nog a,b,c,d....Z (any letter).

How to affect other elements when one element is hovered

Using the sibling selector is the general solution for styling other elements when hovering over a given one, but it works only if the other elements follow the given one in the DOM. What can we do when the other elements should actually be before the hovered one? Say we want to implement a signal bar rating widget like the one below:

Signal bar rating widget

This can actually be done easily using the CSS flexbox model, by setting flex-direction to reverse, so that the elements are displayed in the opposite order from the one they're in the DOM. The screenshot above is from such a widget, implemented with pure CSS.

Flexbox is very well supported by 95% of modern browsers.

_x000D_
_x000D_
.rating {_x000D_
  display: flex;_x000D_
  flex-direction: row-reverse;_x000D_
  width: 9rem;_x000D_
}_x000D_
.rating div {_x000D_
  flex: 1;_x000D_
  align-self: flex-end;_x000D_
  background-color: black;_x000D_
  border: 0.1rem solid white;_x000D_
}_x000D_
.rating div:hover {_x000D_
  background-color: lightblue;_x000D_
}_x000D_
.rating div[data-rating="1"] {_x000D_
  height: 5rem;_x000D_
}_x000D_
.rating div[data-rating="2"] {_x000D_
  height: 4rem;_x000D_
}_x000D_
.rating div[data-rating="3"] {_x000D_
  height: 3rem;_x000D_
}_x000D_
.rating div[data-rating="4"] {_x000D_
  height: 2rem;_x000D_
}_x000D_
.rating div[data-rating="5"] {_x000D_
  height: 1rem;_x000D_
}_x000D_
.rating div:hover ~ div {_x000D_
  background-color: lightblue;_x000D_
}
_x000D_
<div class="rating">_x000D_
  <div data-rating="1"></div>_x000D_
  <div data-rating="2"></div>_x000D_
  <div data-rating="3"></div>_x000D_
  <div data-rating="4"></div>_x000D_
  <div data-rating="5"></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to uninstall Golang?

only tab
rm -rvf /usr/local/go/
not works well, but
sudo rm -rvf /usr/local/go/
do.

UITableView, Separator color where to set?

- (void)viewDidLoad
{
   [self.tableView setSeparatorColor:[UIColor myColor]];
}

I hope that helps - you'll need the self. to access it, remember.

Swift 4.2

tableView.separatorColor = UIColor.red

String comparison - Android

String unlike int or other numeric variables are compared in Java differently than other languages.

To compare Strings in Java (android) it is used the method .compareTo();

so the code should be like this:

if(gender.compareTo("Male")==0){
   salutation ="Mr.";
}
if(gender.compareTo("Female")==0){
   salutation ="Ms.";
}

How to get the file-path of the currently executing javascript code

All browsers except Internet Explorer (any version) have document.currentScript, which always works always (no matter how the file was included (async, bookmarklet etc)).

If you want to know the full URL of the JS file you're in right now:

var script = document.currentScript;
var fullUrl = script.src;

Tadaa.

How to upload, display and save images using node.js and express

First of all, you should make an HTML form containing a file input element. You also need to set the form's enctype attribute to multipart/form-data:

<form method="post" enctype="multipart/form-data" action="/upload">
    <input type="file" name="file">
    <input type="submit" value="Submit">
</form>

Assuming the form is defined in index.html stored in a directory named public relative to where your script is located, you can serve it this way:

const http = require("http");
const path = require("path");
const fs = require("fs");

const express = require("express");

const app = express();
const httpServer = http.createServer(app);

const PORT = process.env.PORT || 3000;

httpServer.listen(PORT, () => {
  console.log(`Server is listening on port ${PORT}`);
});

// put the HTML file containing your form in a directory named "public" (relative to where this script is located)
app.get("/", express.static(path.join(__dirname, "./public")));

Once that's done, users will be able to upload files to your server via that form. But to reassemble the uploaded file in your application, you'll need to parse the request body (as multipart form data).

In Express 3.x you could use express.bodyParser middleware to handle multipart forms but as of Express 4.x, there's no body parser bundled with the framework. Luckily, you can choose from one of the many available multipart/form-data parsers out there. Here, I'll be using multer:

You need to define a route to handle form posts:

const multer = require("multer");

const handleError = (err, res) => {
  res
    .status(500)
    .contentType("text/plain")
    .end("Oops! Something went wrong!");
};

const upload = multer({
  dest: "/path/to/temporary/directory/to/store/uploaded/files"
  // you might also want to set some limits: https://github.com/expressjs/multer#limits
});


app.post(
  "/upload",
  upload.single("file" /* name attribute of <file> element in your form */),
  (req, res) => {
    const tempPath = req.file.path;
    const targetPath = path.join(__dirname, "./uploads/image.png");

    if (path.extname(req.file.originalname).toLowerCase() === ".png") {
      fs.rename(tempPath, targetPath, err => {
        if (err) return handleError(err, res);

        res
          .status(200)
          .contentType("text/plain")
          .end("File uploaded!");
      });
    } else {
      fs.unlink(tempPath, err => {
        if (err) return handleError(err, res);

        res
          .status(403)
          .contentType("text/plain")
          .end("Only .png files are allowed!");
      });
    }
  }
);

In the example above, .png files posted to /upload will be saved to uploaded directory relative to where the script is located.

In order to show the uploaded image, assuming you already have an HTML page containing an img element:

<img src="/image.png" />

you can define another route in your express app and use res.sendFile to serve the stored image:

app.get("/image.png", (req, res) => {
  res.sendFile(path.join(__dirname, "./uploads/image.png"));
});

How do I execute multiple SQL Statements in Access' Query Editor?

"I hoped (and still hope) that there is something like my beloved SQL*Plus for Oracle that can execute a file with all kinds of SQL Statements."

If you're looking for a simple program that can import a file and execute the SQL statements in it, take a look at DBWConsole (freeware). I have used it to process DDL scripts (table schema) as well as action queries. It does not return data sets so it's not useful for SELECT queries. It supports single line comments prefixed by -- but not multi-line comments wrapped in /* */. It supports command line parameters.

enter image description here

If you want an interactive UI like Oracle SQL Developer or SSMS for Access then Matthew Lock's reference to WinSQL is what you should try.

How do you print in Sublime Text 2

  1. Install the Package Control first and restart your editor. See: How to install plugins to Sublime Text 2 editor?
  2. Install Highlight plugin.
    1. Open the pallete, press ctrl+shift+p (Win, Linux) or cmd+shift+p (OS X).
    2. Type and confirm: Install Package
    3. Type and confirm: Highlight or Print

Also see related printing forum topic: Printing from sublime

How to get the file name from a full path using JavaScript?

function getFileName(path, isExtension){

  var fullFileName, fileNameWithoutExtension;

  // replace \ to /
  while( path.indexOf("\\") !== -1 ){
    path = path.replace("\\", "/");
  }

  fullFileName = path.split("/").pop();
  return (isExtension) ? fullFileName : fullFileName.slice( 0, fullFileName.lastIndexOf(".") );
}

How to specify jdk path in eclipse.ini on windows 8 when path contains space

I was facing the same issue but was unable to solve, until I try this:

  1. Please make sure you put -vm
  2. Then press Enter
  3. And then paste C:\Program Files\Java\jdk1.6.0_07\bin\javaw.exe

jQuery If DIV Doesn't Have Class "x"

I think the author was looking for:

$(this).not('.selected')

How to install a specific version of package using Composer?

I tried to require a development branch from a different repository and not the latest version and I had the same issue and non of the above worked for me :(

after a while I saw in the documentation that in cases of dev branch you need to require with a 'dev-' prefix to the version and the following worked perfectly.

composer require [vendorName]/[packageName]:dev-[gitBranchName]

How to define an empty object in PHP

$x = new stdClass();

A comment in the manual sums it up best:

stdClass is the default PHP object. stdClass has no properties, methods or parent. It does not support magic methods, and implements no interfaces.

When you cast a scalar or array as Object, you get an instance of stdClass. You can use stdClass whenever you need a generic object instance.

How do I express "if value is not empty" in the VBA language?

I think the solution of this issue can be some how easier than we imagine. I have simply used the expression Not Null and it worked fine.

Browser("micclass").Page("micclass").WebElement("Test").CheckProperty "innertext", Not Null

Fitting empirical distribution to theoretical ones with Scipy (Python)?

Distribution Fitting with Sum of Square Error (SSE)

This is an update and modification to Saullo's answer, that uses the full list of the current scipy.stats distributions and returns the distribution with the least SSE between the distribution's histogram and the data's histogram.

Example Fitting

Using the El Niño dataset from statsmodels, the distributions are fit and error is determined. The distribution with the least error is returned.

All Distributions

All Fitted Distributions

Best Fit Distribution

Best Fit Distribution

Example Code

%matplotlib inline

import warnings
import numpy as np
import pandas as pd
import scipy.stats as st
import statsmodels as sm
import matplotlib
import matplotlib.pyplot as plt

matplotlib.rcParams['figure.figsize'] = (16.0, 12.0)
matplotlib.style.use('ggplot')

# Create models from data
def best_fit_distribution(data, bins=200, ax=None):
    """Model data by finding best fit distribution to data"""
    # Get histogram of original data
    y, x = np.histogram(data, bins=bins, density=True)
    x = (x + np.roll(x, -1))[:-1] / 2.0

    # Distributions to check
    DISTRIBUTIONS = [        
        st.alpha,st.anglit,st.arcsine,st.beta,st.betaprime,st.bradford,st.burr,st.cauchy,st.chi,st.chi2,st.cosine,
        st.dgamma,st.dweibull,st.erlang,st.expon,st.exponnorm,st.exponweib,st.exponpow,st.f,st.fatiguelife,st.fisk,
        st.foldcauchy,st.foldnorm,st.frechet_r,st.frechet_l,st.genlogistic,st.genpareto,st.gennorm,st.genexpon,
        st.genextreme,st.gausshyper,st.gamma,st.gengamma,st.genhalflogistic,st.gilbrat,st.gompertz,st.gumbel_r,
        st.gumbel_l,st.halfcauchy,st.halflogistic,st.halfnorm,st.halfgennorm,st.hypsecant,st.invgamma,st.invgauss,
        st.invweibull,st.johnsonsb,st.johnsonsu,st.ksone,st.kstwobign,st.laplace,st.levy,st.levy_l,st.levy_stable,
        st.logistic,st.loggamma,st.loglaplace,st.lognorm,st.lomax,st.maxwell,st.mielke,st.nakagami,st.ncx2,st.ncf,
        st.nct,st.norm,st.pareto,st.pearson3,st.powerlaw,st.powerlognorm,st.powernorm,st.rdist,st.reciprocal,
        st.rayleigh,st.rice,st.recipinvgauss,st.semicircular,st.t,st.triang,st.truncexpon,st.truncnorm,st.tukeylambda,
        st.uniform,st.vonmises,st.vonmises_line,st.wald,st.weibull_min,st.weibull_max,st.wrapcauchy
    ]

    # Best holders
    best_distribution = st.norm
    best_params = (0.0, 1.0)
    best_sse = np.inf

    # Estimate distribution parameters from data
    for distribution in DISTRIBUTIONS:

        # Try to fit the distribution
        try:
            # Ignore warnings from data that can't be fit
            with warnings.catch_warnings():
                warnings.filterwarnings('ignore')

                # fit dist to data
                params = distribution.fit(data)

                # Separate parts of parameters
                arg = params[:-2]
                loc = params[-2]
                scale = params[-1]

                # Calculate fitted PDF and error with fit in distribution
                pdf = distribution.pdf(x, loc=loc, scale=scale, *arg)
                sse = np.sum(np.power(y - pdf, 2.0))

                # if axis pass in add to plot
                try:
                    if ax:
                        pd.Series(pdf, x).plot(ax=ax)
                    end
                except Exception:
                    pass

                # identify if this distribution is better
                if best_sse > sse > 0:
                    best_distribution = distribution
                    best_params = params
                    best_sse = sse

        except Exception:
            pass

    return (best_distribution.name, best_params)

def make_pdf(dist, params, size=10000):
    """Generate distributions's Probability Distribution Function """

    # Separate parts of parameters
    arg = params[:-2]
    loc = params[-2]
    scale = params[-1]

    # Get sane start and end points of distribution
    start = dist.ppf(0.01, *arg, loc=loc, scale=scale) if arg else dist.ppf(0.01, loc=loc, scale=scale)
    end = dist.ppf(0.99, *arg, loc=loc, scale=scale) if arg else dist.ppf(0.99, loc=loc, scale=scale)

    # Build PDF and turn into pandas Series
    x = np.linspace(start, end, size)
    y = dist.pdf(x, loc=loc, scale=scale, *arg)
    pdf = pd.Series(y, x)

    return pdf

# Load data from statsmodels datasets
data = pd.Series(sm.datasets.elnino.load_pandas().data.set_index('YEAR').values.ravel())

# Plot for comparison
plt.figure(figsize=(12,8))
ax = data.plot(kind='hist', bins=50, normed=True, alpha=0.5, color=plt.rcParams['axes.color_cycle'][1])
# Save plot limits
dataYLim = ax.get_ylim()

# Find best fit distribution
best_fit_name, best_fit_params = best_fit_distribution(data, 200, ax)
best_dist = getattr(st, best_fit_name)

# Update plots
ax.set_ylim(dataYLim)
ax.set_title(u'El Niño sea temp.\n All Fitted Distributions')
ax.set_xlabel(u'Temp (°C)')
ax.set_ylabel('Frequency')

# Make PDF with best params 
pdf = make_pdf(best_dist, best_fit_params)

# Display
plt.figure(figsize=(12,8))
ax = pdf.plot(lw=2, label='PDF', legend=True)
data.plot(kind='hist', bins=50, normed=True, alpha=0.5, label='Data', legend=True, ax=ax)

param_names = (best_dist.shapes + ', loc, scale').split(', ') if best_dist.shapes else ['loc', 'scale']
param_str = ', '.join(['{}={:0.2f}'.format(k,v) for k,v in zip(param_names, best_fit_params)])
dist_str = '{}({})'.format(best_fit_name, param_str)

ax.set_title(u'El Niño sea temp. with best fit distribution \n' + dist_str)
ax.set_xlabel(u'Temp. (°C)')
ax.set_ylabel('Frequency')

Simplest way to throw an error/exception with a custom message in Swift 2?

Based on @Nick keets answer, here is a more complete example:

extension String: Error {} // Enables you to throw a string

extension String: LocalizedError { // Adds error.localizedDescription to Error instances
    public var errorDescription: String? { return self }
}

func test(color: NSColor) throws{
    if color == .red {
        throw "I don't like red"
    }else if color == .green {
        throw "I'm not into green"
    }else {
        throw "I like all other colors"
    }
}

do {
    try test(color: .green)
} catch let error where error.localizedDescription == "I don't like red"{
    Swift.print ("Error: \(error)") // "I don't like red"
}catch let error {
    Swift.print ("Other cases: Error: \(error.localizedDescription)") // I like all other colors
}

Originally published on my swift blog: http://eon.codes/blog/2017/09/01/throwing-simple-errors/

Simple If/Else Razor Syntax

A little bit off topic maybe, but for modern browsers (IE9 and newer) you can use the css odd/even selectors to achieve want you want.

tr:nth-child(even) { /* your alt-row stuff */}
tr:nth-child(odd) { /* the other rows */ }

or

tr { /* all table rows */ }
tr:nth-child(even) { /* your alt-row stuff */}

jQuery find events handlers registered with an object

jQuery is not letting you just simply access the events for a given element. You can access them using undocumented internal method

$._data(element, "events")

But it still won't give you all the events, to be precise won't show you events assigned with

$([selector|element]).on()

These events are stored inside document, so you can fetch them by browsing through

$._data(document, "events")

but that is hard work, as there are events for whole webpage.

Tom G above created function that filters document for only events of given element and merges output of both methods, but it had a flaw of duplicating events in the output (and effectively on the element's jQuery internal event list messing with your application). I fixed that flaw and you can find the code below. Just paste it into your dev console or into your app code and execute it when needed to get nice list of all events for given element.

What is important to notice, element is actually HTMLElement, not jQuery object.

function getEvents(element) {
    var elemEvents = $._data(element, "events");
    var allDocEvnts = $._data(document, "events");
    function equalEvents(evt1, evt2)
    {
        return evt1.guid === evt2.guid;
    }

    for(var evntType in allDocEvnts) {
        if(allDocEvnts.hasOwnProperty(evntType)) {
            var evts = allDocEvnts[evntType];
            for(var i = 0; i < evts.length; i++) {
                if($(element).is(evts[i].selector)) {
                    if(elemEvents == null) {
                        elemEvents = {};
                    }
                    if(!elemEvents.hasOwnProperty(evntType)) {
                        elemEvents[evntType] = [];
                    }
                    if(!elemEvents[evntType].some(function(evt) { return equalEvents(evt, evts[i]); })) {
                        elemEvents[evntType].push(evts[i]);
                    }
                }
            }
        }
    }
    return elemEvents;
}

How does Tomcat find the HOME PAGE of my Web App?

I already had index.html in the WebContent folder but it was not showing up , finally i added the following piece of code in my projects web.xml and it started showing up

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

Array of strings in groovy

If you really want to create an array rather than a list use either

String[] names = ["lucas", "Fred", "Mary"]

or

def names = ["lucas", "Fred", "Mary"].toArray()

How to sort a list of objects based on an attribute of the objects?

Add rich comparison operators to the object class, then use sort() method of the list.
See rich comparison in python.


Update: Although this method would work, I think solution from Triptych is better suited to your case because way simpler.

Sending message through WhatsApp

This works to me:

public static void shareWhatsApp(Activity appActivity, String texto) {

    Intent sendIntent = new Intent(Intent.ACTION_SEND);     
    sendIntent.setType("text/plain");
    sendIntent.putExtra(android.content.Intent.EXTRA_TEXT, texto);

    PackageManager pm = appActivity.getApplicationContext().getPackageManager();
    final List<ResolveInfo> matches = pm.queryIntentActivities(sendIntent, 0);
    boolean temWhatsApp = false;
    for (final ResolveInfo info : matches) {
      if (info.activityInfo.packageName.startsWith("com.whatsapp"))  {
          final ComponentName name = new ComponentName(info.activityInfo.applicationInfo.packageName, info.activityInfo.name);
          sendIntent.addCategory(Intent.CATEGORY_LAUNCHER);
          sendIntent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_NEW_TASK);
          sendIntent.setComponent(name);
          temWhatsApp = true;
          break;
      }
    }               

    if(temWhatsApp) {
        //abre whatsapp
        appActivity.startActivity(sendIntent);
    } else {
        //alerta - você deve ter o whatsapp instalado
        Toast.makeText(appActivity, appActivity.getString(R.string.share_whatsapp), Toast.LENGTH_SHORT).show();
    }
}

What is Activity.finish() method doing exactly?

In addition to @rommex answer above, I have also noticed that finish() does queue the destruction of the Activity and that it depends on Activity priority.

If I call finish() after onPause(), I see onStop(), and onDestroy() immediately called.

If I call finish() after onStop(), I don't see onDestroy() until 5 minutes later.

From my observation, it looks like finish is queued up and when I looked at the adb shell dumpsys activity activities it was set to finishing=true, but since it is no longer in the foreground, it wasn't prioritized for destruction.

In summary, onDestroy() is never guaranteed to be called, but even in the case it is called, it could be delayed.

g++ undefined reference to typeinfo

This occurs when declared (non-pure) virtual functions are missing bodies. In your class definition, something like:

virtual void foo();

Should be defined (inline or in a linked source file):

virtual void foo() {}

Or declared pure virtual:

virtual void foo() = 0;

Checking if a field contains a string

As Mongo shell support regex, that's completely possible.

db.users.findOne({"username" : /.*son.*/});

If we want the query to be case-insensitive, we can use "i" option, like shown below:

db.users.findOne({"username" : /.*son.*/i});

See: http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-RegularExpressions

Project Links do not work on Wamp Server

This works on Wamp 3+.

  • Go to wamp folder (wamp/ or wamp64/)
  • Open wampmanager.conf
  • Find urlAddLocalhost param and set it on: urlAddLocalhost = "on"

There should not be the need to tweak the index.php in www folder.

Sorting options elements alphabetically using jQuery

What I'd do is:

  1. Extract the text and value of each <option> into an array of objects;
  2. Sort the array;
  3. Update the <option> elements with the array contents in order.

To do that with jQuery, you could do this:

var options = $('select.whatever option');
var arr = options.map(function(_, o) { return { t: $(o).text(), v: o.value }; }).get();
arr.sort(function(o1, o2) { return o1.t > o2.t ? 1 : o1.t < o2.t ? -1 : 0; });
options.each(function(i, o) {
  o.value = arr[i].v;
  $(o).text(arr[i].t);
});

Here is a working jsfiddle.

edit — If you want to sort such that you ignore alphabetic case, you can use the JavaScript .toUpperCase() or .toLowerCase() functions before comparing:

arr.sort(function(o1, o2) {
  var t1 = o1.t.toLowerCase(), t2 = o2.t.toLowerCase();

  return t1 > t2 ? 1 : t1 < t2 ? -1 : 0;
});

How to test an Internet connection with bash?

Similarly to @Jesse's answer, this option might be much faster than any solution using ping and perhaps slightly more efficient than @Jesse's answer.

find /sys/class/net/ -maxdepth 1 -mindepth 1 ! -name "*lo*" -exec sh -c 'cat "$0"/carrier 2>&1' {} \; | grep -q '1'

Explenation:

This command uses find with -exec to run command on all files not named *lo* in /sys/class/net/. These should be links to directories containing information about the available network interfaces on your machine.

The command being ran is an sh command that checks the contents of the file carrier in those directories. The value of $interface/carrier has 3 meanings - Quoting:

It seems there are three states:

  • ./carrier not readable (for instance when the interface is disabled in Network Manager).
  • ./carrier contain "1" (when the interface is activated and it is connected to a WiFi network)
  • ./carrier contain "0" (when the interface is activated and it is not connected to a WiFi network)

The first option is not taken care of in @Jesse's answer. The sh command striped out is:

# Note: $0 == $interface
cat "$0"/carrier 2>&1

cat is being used to check the contents of carrier and redirect all output to standard output even when it fails because the file is not readable. If grep -q finds "1" among those files it means there is at least 1 interface connected. The exit code of grep -q will be the final exit code.

Usage

For example, using this command's exit status, you can use it start a gnubiff in your ~/.xprofile only if you have an internet connection.

online() {
    find /sys/class/net/ -maxdepth 1 -mindepth 1 ! -name "*lo*" -exec sh -c 'cat "$0"/carrier 2>&1 > /dev/null | grep -q "1" && exit 0' {} \;
}
online && gnubiff --systemtray --noconfigure &

Reference

How to select true/false based on column value?

At least in Postgres you can use the following statement:

SELECT EntityID, EntityName, EntityProfile IS NOT NULL AS HasProfile FROM Entity

How to uncheck a checkbox in pure JavaScript?

<html>
    <body>
        <input id="mycheck" type="checkbox">
    </body>

    <script language="javascript">
        var=check;
        document.getElementById("mycheck");
        check.checked="false";
    </script>
</html>

How do I create a basic UIButton programmatically?

-(void)addStuffToView
{
    UIButton *aButton = [[UIButton alloc] initWithFrame:CGRectMake(20, 20, 20, 20)]; //(x, y, width, height of button on screen
    [aButton setTitle:@"Button" forState:UIControlStateNormal];//puts the text on the button
    aButton.titleLabel.font = somefont;//sets the font if one is already stated
    aButton.titleLabel.font = [UIFont fontWithName:@"Arial-MT" size:12];//sets the font type and size
    [aButton addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];//see back method below
    [aButton setBackgroundImage:[UIImage imageNamed:@"someImage.png"] forState:UIControlStateNormal];//sets the image of the button
    [self.view addSubview:back];
}

-(void)back
{
    UIAlertView *alert = [[UIAlertView alloc]initWithTitle.....]
}

-(void)viewDidLoad
{
    [super viewDidLoad];
    [self addStuffToView];//adds all items built in this method to the view
}

How to add AUTO_INCREMENT to an existing column?

I managed to do this with the following code:

ALTER TABLE `table_name`
CHANGE COLUMN `colum_name` `colum_name` INT(11) NOT NULL AUTO_INCREMENT FIRST;

This is the only way I could make a column auto increment.

INT(11) shows that the maximum int length is 11, you can skip it if you want.

Git ignore local file changes

git pull wants you to either remove or save your current work so that the merge it triggers doesn't cause conflicts with your uncommitted work. Note that you should only need to remove/save untracked files if the changes you're pulling create files in the same locations as your local uncommitted files.

Remove your uncommitted changes

Tracked files

git checkout -f

Untracked files

git clean -fd

Save your changes for later

Tracked files

git stash

Tracked files and untracked files

git stash -u

Reapply your latest stash after git pull:

git stash pop

gradlew command not found?

If the answer marked as correct does not work, it is because you need to identify yourself as a super user.

sudo gradle wrapper --gradle-version 2.13

It worked for me.

Get User Selected Range

Selection is its own object within VBA. It functions much like a Range object.

Selection and Range do not share all the same properties and methods, though, so for ease of use it might make sense just to create a range and set it equal to the Selection, then you can deal with it programmatically like any other range.

Dim myRange as Range
Set myRange = Selection

For further reading, check out the MSDN article.

CSS: borders between table columns only

I used this in a style sheet for three columns separated by vertical borders and it worked fine:

#column-left {
     border-left: 1px solid #dddddd;
}
#column-center {
     /*no border needed/*
}
#column-right {
     border-right: 1px solid #dddddd;
}

The column on the left gets a border on the right, the column on the right gets a border on the left and the the middle column is already taken care of by the left and right.

If your columns are inside a div/wrapper/table/etc... don't forget to add extra space to accomodate the width of the borders.

How to dismiss ViewController in Swift?

If you are presenting a ViewController modally, and want to go back to the root ViewController, take care to dismiss this modally presented ViewController before you go back to the root ViewController otherwise this ViewController will not be removed from Memory and cause Memory leaks.

"Permission Denied" trying to run Python on Windows 10

This appears to be a limitation in git-bash. The recommendation to use winpty python.exe worked for me. See Python not working in the command line of git bash for additional information.

How to create timer in angular2

import {Component, View, OnInit, OnDestroy} from "angular2/core";

import { Observable, Subscription } from 'rxjs/Rx';

@Component({

})
export class NewContactComponent implements OnInit, OnDestroy {

    ticks = 0;
    private timer;
    // Subscription object
    private sub: Subscription;


    ngOnInit() {
        this.timer = Observable.timer(2000,5000);
        // subscribing to a observable returns a subscription object
        this.sub = this.timer.subscribe(t => this.tickerFunc(t));
    }
    tickerFunc(tick){
        console.log(this);
        this.ticks = tick
    }

    ngOnDestroy(){
        console.log("Destroy timer");
        // unsubscribe here
        this.sub.unsubscribe();

    }


}

MongoDB: Combine data from multiple collections into one..how?

Mongorestore has this feature of appending on top of whatever is already in the database, so this behavior could be used for combining two collections:

  1. mongodump collection1
  2. collection2.rename(collection1)
  3. mongorestore

Didn't try it yet, but it might perform faster than the map/reduce approach.

How to get all the AD groups for a particular user?

You should use System.DirectoryServices.AccountManagement. It's much easier. Here is a nice code project article giving you an overview on all the classes in this DLL.

As you pointed out, your current approach doesn't find out the primary group. Actually, it's much worse than you thought. There are some more cases that it doesn't work, like the domain local group from another domain. You can check here for details. Here is how the code looks like if you switch to use System.DirectoryServices.AccountManagement. The following code can find the immediate groups this user assigned to, which includes the primary group.

UserPrincipal user = UserPrincipal.FindByIdentity(new PrincipalContext (ContextType.Domain, "mydomain.com"), IdentityType.SamAccountName, "username");
foreach (GroupPrincipal group in user.GetGroups())
{
    Console.Out.WriteLine(group);
}

PHP: Count a stdClass object

The object doesn't have 30 properties. It has one, which is an array that has 30 elements. You need the number of elements in that array.

Return multiple values in JavaScript?

Another worth to mention newly introduced (ES6) syntax is use of object creation shorthand in addition to destructing assignment.

function fun1() {
  var x = 'a';
  var y = 'b';
  return { x, y, z: 'c' };
  // literally means { x: x, y: y, z: 'c' };
}

var { z, x, y } = fun1(); // order or full presence is not really important
// literally means var r = fun1(), x = r.x, y = r.y, z = r.z;
console.log(x, y, z);

This syntax can be polyfilled with babel or other js polyfiller for older browsers but fortunately now works natively with the recent versions of Chrome and Firefox.

But as making a new object, memory allocation (and eventual gc load) are involved here, don't expect much performance from it. JavaScript is not best language for developing highly optimal things anyways but if that is needed, you can consider putting your result on surrounding object or such techniques which are usually common performance tricks between JavaScript, Java and other languages.

How to make a JFrame Modal in Swing java

This static utility method shows a modal JFrame by secretly opening a modal JDialog, too. I used this successfully and with proper behavior on Windows 7, 8, and 10-with-multiple-desktops.

It's a nice example for the very rarely used feature of local classes.

import javax.swing.*;
import java.awt.Dialog;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

// ... (class declaration)

/**
 * Shows an already existing JFrame as if it were a modal JDialog. JFrames have the upside that they can be
 * maximized.
 * <p>
 * A hidden modal JDialog is "shown" to effect the modality.
 * <p>
 * When the JFrame is closed, this method's listener will pick up on that, close the modal JDialog, and remove the
 * listener.
 *
 * made by dreamspace-president.com
 *
 * @param window the JFrame to be shown
 * @param owner  the owner window (can be null)
 * @throws IllegalArgumentException if argument "window" is null
 */
public static void showModalJFrame(final JFrame window, final Frame owner) {

    if (window == null) {
        throw new IllegalArgumentException();
    }
    window.setModalExclusionType(Dialog.ModalExclusionType.APPLICATION_EXCLUDE);
    window.setVisible(true);
    window.setAlwaysOnTop(true);

    final JDialog hiddenDialogForModality = new JDialog(owner, true);
    final class MyWindowCloseListener extends WindowAdapter {
        @Override
        public void windowClosed(final WindowEvent e) {
            window.dispose();
            hiddenDialogForModality.dispose();
        }
    }

    final MyWindowCloseListener myWindowCloseListener = new MyWindowCloseListener();
    window.addWindowListener(myWindowCloseListener);

    final Dimension smallSize = new Dimension(80, 80);
    hiddenDialogForModality.setMinimumSize(smallSize);
    hiddenDialogForModality.setSize(smallSize);
    hiddenDialogForModality.setMaximumSize(smallSize);
    hiddenDialogForModality.setLocation(-smallSize.width * 2, -smallSize.height * 2);
    hiddenDialogForModality.setVisible(true);
    window.removeWindowListener(myWindowCloseListener);
}

TypeError: $ is not a function WordPress

You use jQuery.noConflict(); So $ is undefined.

You can read more about it here docs

Try to modify your code in this way (add $ sign to ready function):

jQuery(document).ready(function($) {
    // Code that uses jQuery's $ can follow here.
});

Visually managing MongoDB documents and collections

The real answer is ... No.

So far as I have found there is no reasonable or publicly available Windows MonogoDB client which is really very sad since MongoDB is pretty sweet.

I've thought about throwing together a simple app with WPF on Codeplex ... but I haven't been super motivated.

What would features would you be interested in having? Maybe you can inspire me or others?

For example, do you just want to view DBs / collections & perhaps simple edits (so you don't have to use the shell) or do you require something more complex?

Conditionally formatting if multiple cells are blank (no numerics throughout spreadsheet )

enter image description here

How about just > Format only cells that contain - in the drop down box select Blanks

document.getElementById replacement in angular4 / typescript?

  element: HTMLElement;

  constructor() {}

  fakeClick(){
    this.element = document.getElementById('ButtonX') as HTMLElement;
    this.element.click();
  }

Error: "setFile(null,false) call failed" when using log4j

if it is window7(like mine), without administrative rights cannot write a file at C: drive

just give another folder in log4j.properties file

Set the name of the file

log4j.appender.FILE.File=C:\server\log.out you can see with notepad++

How do you get current active/default Environment profile programmatically in Spring?

If you're not using autowiring, simply implement EnvironmentAware

Java Convert GMT/UTC to Local time doesn't work as expected

tl;dr

Instant.now()                           // Capture the current moment in UTC.
.atZone( ZoneId.systemDefault() )       // Adjust into the JVM's current default time zone. Same moment, different wall-clock time. Produces a `ZonedDateTime` object.
.toInstant()                            // Extract a `Instant` (always in UTC) object from the `ZonedDateTime` object.
.atZone( ZoneId.of( "Europe/Paris" ) )  // Adjust the `Instant` into a specific time zone. Renders a `ZonedDateTime` object. Same moment, different wall-clock time.
.toInstant()                            // And back to UTC again.

java.time

The modern approach uses the java.time classes that supplanted the troublesome old legacy date-time classes (Date, Calendar, etc.).

Your use of the word "local" contradicts the usage in the java.time class. In java.time, "local" means any locality or all localities, but not any one particular locality. The java.time classes with names starting with "Local…" all lack any concept of time zone or offset-from-UTC. So they do not represent a specific moment, they are not a point on the timeline, whereas your Question is all about moments, points on the timeline viewed through various wall-clock times.

Get the current system time (local time)

If you want to capture the current moment in UTC, use Instant. The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).

Instant instant = Instant.now() ;  // Capture the current moment in UTC.

Adjust into a time zone by applying a ZoneId to get a ZonedDateTime. Same moment, same point on the timeline, different wall-clock time.

Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).

ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = instant.atZone( z ) ;  // Same moment, different wall-clock time.

As a shortcut, you can skip the usage of Instant to get a ZonedDateTime.

ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = ZonedDateTime.now( z ) ;

Convert Local time to UTC // Works Fine Till here

You can adjust from the zoned date-time to UTC by extracting an Instant from a ZonedDateTime.

ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = ZonedDateTime.now( z ) ;
Instant instant = zdt.toInstant() ;

Reverse the UTC time, back to local time.

As shown above, apply a ZoneId to adjust the same moment into another wall-clock time used by the people of a certain region (a time zone).

Instant instant = Instant.now() ;  // Capture current moment in UTC.

ZoneId zDefault = ZoneId.systemDefault() ;  // The JVM's current default time zone.
ZonedDateTime zdtDefault = instant.atZone( zDefault ) ;

ZoneId zTunis = ZoneId.of( "Africa/Tunis" ) ;  // The JVM's current default time zone.
ZonedDateTime zdtTunis = instant.atZone( zTunis ) ;

ZoneId zAuckland = ZoneId.of( "Pacific/Auckland" ) ;  // The JVM's current default time zone.
ZonedDateTime zdtAuckland = instant.atZone( zAuckland ) ;

Going back to UTC from a zoned date-time, call ZonedDateTime::toInstant. Think of it conceptually as: ZonedDateTime = Instant + ZoneId.

Instant instant = zdtAuckland.toInstant() ;

All of these objects, the Instant and the three ZonedDateTime objects all represent the very same simultaneous moment, the same point in history.

Followed 3 different approaches (listed below) but all the 3 approaches retains the time in UTC only.

Forget about trying to fix code using those awful Date, Calendar, and GregorianCalendar classes. They are a wretched mess of bad design and flaws. You need never touch them again. If you must interface with old code not yet updated to java.time, you can convert back-and-forth via new conversion methods added to the old classes.


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How to check undefined in Typescript

In Typescript 2 you can use Undefined type to check for undefined values. So if you declare a variable as:

let uemail : string | undefined;

Then you can check if the variable z is undefined as:

if(uemail === undefined)
{

}

calling a function from class in python - different way

Your methods don't refer to an object (that is, self), so you should use the @staticmethod decorator:

class MathsOperations:
    @staticmethod
    def testAddition (x, y):
        return x + y

    @staticmethod
    def testMultiplication (a, b):
        return a * b

Java web start - Unable to load resource

I'm not sure exactly what the problem is, but I have looked at one of my jnlp files and I have put in the full path to each of my jar files. (I have a velocity template that generates the app.jnlp file which places it in all the correct places when my maven build runs)

One thing I have seen happen is that the jnlp file is re-downloaded by the by the webstart runtime, and it uses the href attribute (which is left blank in your jnlp file) to re-download the file. I would start there, and try adding the full path into the jnlp files too...I've found webstart to be a fickle mistress!

Convert String to Uri

I am just using the java.net package. Here you can do the following:

...
import java.net.URI;
...

String myUrl = "http://stackoverflow.com";
URI myURI = new URI(myUrl);

unable to start mongodb local server

I suggest use instead:

$sudo service mongodb stop

That could work.

How to use regex in file find

Use -regex not -name, and be aware that the regex matches against what find would print, e.g. "/home/test/test.log" not "test.log"

Creating a BAT file for python script

i did this and works: i have my project in D: and my batch file is in the desktop, if u have it in the same drive just ignore the first line and change de D directory in the second line

in the second line change the folder of the file, put your folder

in the third line change the name of the file

D: cd D:\python_proyects\example_folder\ python example_file.py

From ND to 1D arrays

For list of array with different size use following:

import numpy as np

# ND array list with different size
a = [[1],[2,3,4,5],[6,7,8]]

# stack them
b = np.hstack(a)

print(b)

Output:

[1 2 3 4 5 6 7 8]

HTML CSS Invisible Button

button {
    background:transparent;
    border:none;
    outline:none;
    display:block;
    height:200px;
    width:200px;
    cursor:pointer;
}

Give the height and width with respect to the image in the background.This removes the borders and color of a button.You might also need to position it absolute so you can correctly place it where you need.I cant help you further without posting you code

To make it truly invisible you have to set outline:none; otherwise there would be a blue outline in some browsers and you have to set display:block if you need to click it and set dimensions to it

How to remove first and last character of a string?

this is perfectly working fine

String str = "[wdsd34svdf]";
//String str1 = str.replace("[","").replace("]", "");
String str1 = str.replaceAll("[^a-zA-Z0-9]", "");
System.out.println(str1);


String strr = "[wdsd(340) svdf]";
String strr1 = str.replaceAll("[^a-zA-Z0-9]", "");
System.out.println(strr1);

Python Selenium Chrome Webdriver

Here's a simpler solution: install python-chromedrive package, import it in your script, and it's done.

Step by step:
1. pip install chromedriver-binary
2. import the package

from selenium import webdriver
import chromedriver_binary  # Adds chromedriver binary to path

driver = webdriver.Chrome()
driver.get("http://www.python.org")

Reference: https://pypi.org/project/chromedriver-binary/

Is it possible to use if...else... statement in React render function?

If you need more than one condition, so you can try this out

https://www.npmjs.com/package/react-if-elseif-else-render

import { If, Then, ElseIf, Else } from 'react-if-elseif-else-render';

class Example extends Component {

  render() {
    var i = 3; // it will render '<p>Else</p>'
    return (
      <If condition={i == 1}>
        <Then>
          <p>Then: 1</p>
        </Then>
        <ElseIf condition={i == 2}>
          <p>ElseIf: 2</p>
        </ElseIf>
        <Else>
          <p>Else</p>
        </Else>
      </If>
    );
  }
}

OAuth2 and Google API: access token expiration time?

You shouldn't design your application based on specific lifetimes of access tokens. Just assume they are (very) short lived.

However, after a successful completion of the OAuth2 installed application flow, you will get back a refresh token. This refresh token never expires, and you can use it to exchange it for an access token as needed. Save the refresh tokens, and use them to get access tokens on-demand (which should then immediately be used to get access to user data).

EDIT: My comments above notwithstanding, there are two easy ways to get the access token expiration time:

  1. It is a parameter in the response (expires_in)when you exchange your refresh token (using /o/oauth2/token endpoint). More details.
  2. There is also an API that returns the remaining lifetime of the access_token:

    https://www.googleapis.com/oauth2/v1/tokeninfo?access_token={accessToken}

    This will return a json array that will contain an expires_in parameter, which is the number of seconds left in the lifetime of the token.

'dict' object has no attribute 'has_key'

The whole code in the document will be:

graph = {'A': ['B', 'C'],
             'B': ['C', 'D'],
             'C': ['D'],
             'D': ['C'],
             'E': ['F'],
             'F': ['C']}
def find_path(graph, start, end, path=[]):
        path = path + [start]
        if start == end:
            return path
        if start not in graph:
            return None
        for node in graph[start]:
            if node not in path:
                newpath = find_path(graph, node, end, path)
                if newpath: return newpath
        return None

After writing it, save the document and press F 5

After that, the code you will run in the Python IDLE shell will be:

find_path(graph, 'A','D')

The answer you should receive in IDLE is

['A', 'B', 'C', 'D'] 

J2ME/Android/BlackBerry - driving directions, route between two locations

J2ME Map Route Provider

maps.google.com has a navigation service which can provide you route information in KML format.

To get kml file we need to form url with start and destination locations:

public static String getUrl(double fromLat, double fromLon,
                            double toLat, double toLon) {// connect to map web service
    StringBuffer urlString = new StringBuffer();
    urlString.append("http://maps.google.com/maps?f=d&hl=en");
    urlString.append("&saddr=");// from
    urlString.append(Double.toString(fromLat));
    urlString.append(",");
    urlString.append(Double.toString(fromLon));
    urlString.append("&daddr=");// to
    urlString.append(Double.toString(toLat));
    urlString.append(",");
    urlString.append(Double.toString(toLon));
    urlString.append("&ie=UTF8&0&om=0&output=kml");
    return urlString.toString();
}

Next you will need to parse xml (implemented with SAXParser) and fill data structures:

public class Point {
    String mName;
    String mDescription;
    String mIconUrl;
    double mLatitude;
    double mLongitude;
}

public class Road {
    public String mName;
    public String mDescription;
    public int mColor;
    public int mWidth;
    public double[][] mRoute = new double[][] {};
    public Point[] mPoints = new Point[] {};
}

Network connection is implemented in different ways on Android and Blackberry, so you will have to first form url:

 public static String getUrl(double fromLat, double fromLon,
     double toLat, double toLon)

then create connection with this url and get InputStream.
Then pass this InputStream and get parsed data structure:

 public static Road getRoute(InputStream is) 

Full source code RoadProvider.java

BlackBerry

class MapPathScreen extends MainScreen {
    MapControl map;
    Road mRoad = new Road();
    public MapPathScreen() {
        double fromLat = 49.85, fromLon = 24.016667;
        double toLat = 50.45, toLon = 30.523333;
        String url = RoadProvider.getUrl(fromLat, fromLon, toLat, toLon);
        InputStream is = getConnection(url);
        mRoad = RoadProvider.getRoute(is);
        map = new MapControl();
        add(new LabelField(mRoad.mName));
        add(new LabelField(mRoad.mDescription));
        add(map);
    }
    protected void onUiEngineAttached(boolean attached) {
        super.onUiEngineAttached(attached);
        if (attached) {
            map.drawPath(mRoad);
        }
    }
    private InputStream getConnection(String url) {
        HttpConnection urlConnection = null;
        InputStream is = null;
        try {
            urlConnection = (HttpConnection) Connector.open(url);
            urlConnection.setRequestMethod("GET");
            is = urlConnection.openInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
}

See full code on J2MEMapRouteBlackBerryEx on Google Code

Android

Android G1 screenshot

public class MapRouteActivity extends MapActivity {
    LinearLayout linearLayout;
    MapView mapView;
    private Road mRoad;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        new Thread() {
            @Override
            public void run() {
                double fromLat = 49.85, fromLon = 24.016667;
                double toLat = 50.45, toLon = 30.523333;
                String url = RoadProvider
                        .getUrl(fromLat, fromLon, toLat, toLon);
                InputStream is = getConnection(url);
                mRoad = RoadProvider.getRoute(is);
                mHandler.sendEmptyMessage(0);
            }
        }.start();
    }

    Handler mHandler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            TextView textView = (TextView) findViewById(R.id.description);
            textView.setText(mRoad.mName + " " + mRoad.mDescription);
            MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
            List<Overlay> listOfOverlays = mapView.getOverlays();
            listOfOverlays.clear();
            listOfOverlays.add(mapOverlay);
            mapView.invalidate();
        };
    };

    private InputStream getConnection(String url) {
        InputStream is = null;
        try {
            URLConnection conn = new URL(url).openConnection();
            is = conn.getInputStream();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
}

See full code on J2MEMapRouteAndroidEx on Google Code

Remove style attribute from HTML tags

Here you go:

<?php

$html = '<p style="border: 1px solid red;">Test</p>';
echo preg_replace('/<p style="(.+?)">(.+?)<\/p>/i', "<p>$2</p>", $html);

?>

By the way, as pointed out by others, regex are not suggested for this.

git: 'credential-cache' is not a git command

I faced this problem while using AptanaStudio3 on windows7. This helped me:

git config --global credential.helper wincred

Code taken from here

Unable to Resolve Module in React Native App

This is my project directory structure

enter image description here

And i use the import like this

enter image description here

And it is working do not forget to add dot before slash for example './src/container/home/profile/index'

How to convert an object to JSON correctly in Angular 2 with TypeScript

In your product.service.ts you are using stringify method in a wrong way..

Just use

JSON.stringify(product) 

instead of

JSON.stringify({product})

i have checked your problem and after this it's working absolutely fine.

Cant get text of a DropDownList in code - can get value but not text

Have a look here, this has a proof-of-concept page and demo you can use to get anything from the drop-down: asp:DropDownList Control Tutorial Page

Why extend the Android Application class?

Sometimes you want to store data, like global variables which need to be accessed from multiple Activities - sometimes everywhere within the application. In this case, the Application object will help you.

For example, if you want to get the basic authentication data for each http request, you can implement the methods for authentication data in the application object.

After this,you can get the username and password in any of the activities like this:

MyApplication mApplication = (MyApplication)getApplicationContext();
String username = mApplication.getUsername();
String password = mApplication.getPassword();

And finally, do remember to use the Application object as a singleton object:

 public class MyApplication extends Application {
    private static MyApplication singleton;

    public MyApplication getInstance(){
        return singleton;
    }
    @Override
    public void onCreate() {
        super.onCreate();
        singleton = this;
    }
}

For more information, please Click Application Class

Pandas sort by group aggregate and column

Here's a more concise approach...

df['a_bsum'] = df.groupby('A')['B'].transform(sum)
df.sort(['a_bsum','C'], ascending=[True, False]).drop('a_bsum', axis=1)

The first line adds a column to the data frame with the groupwise sum. The second line performs the sort and then removes the extra column.

Result:

    A       B           C
5   baz     -2.301539   True
2   baz     -0.528172   False
1   bar     -0.611756   True
4   bar      0.865408   False
3   foo     -1.072969   True
0   foo      1.624345   False

NOTE: sort is deprecated, use sort_values instead

Easy way to make a confirmation dialog in Angular?

Here's a slghtly different take using javascript's native confirm functionality and a custom Angular directive. It's super flexible and pretty lightweight:

Usage:

<button (hrsAreYouSure) (then)="confirm(arg1)" (else)="cancel(arg2)">
  This will execute confirm if user presses Ok on the confirmation dialog, or cancel if they
  hit Cancel
</button>

Directive:

import {Directive, ElementRef, EventEmitter, Inject, OnInit, Output} from '@angular/core';

@Directive({
  selector: '[hrsAreYouSure]'
})

export class AreYouSureDirective implements OnInit {

  @Output() then = new EventEmitter<boolean>();
  @Output() else = new EventEmitter<boolean>();

  constructor(@Inject(ElementRef) private element: ElementRef) { }

  ngOnInit(): void {
    const directive = this;
    this.element.nativeElement.onclick = function() {
      const result = confirm('Are you sure?');
      if (result) {
        directive.then.emit(true);
      } else {
        directive.else.emit(true);
      }
    };
  }
}

SQL Server - Return value after INSERT

Entity Framework performs something similar to gbn's answer:

DECLARE @generated_keys table([Id] uniqueidentifier)

INSERT INTO Customers(FirstName)
OUTPUT inserted.CustomerID INTO @generated_keys
VALUES('bob');

SELECT t.[CustomerID]
FROM @generated_keys AS g 
   JOIN dbo.Customers AS t 
   ON g.Id = t.CustomerID
WHERE @@ROWCOUNT > 0

The output results are stored in a temporary table variable, and then selected back to the client. Have to be aware of the gotcha:

inserts can generate more than one row, so the variable can hold more than one row, so you can be returned more than one ID

I have no idea why EF would inner join the ephemeral table back to the real table (under what circumstances would the two not match).

But that's what EF does.

SQL Server 2008 or newer only. If it's 2005 then you're out of luck.

Batchfile to create backup and rename with timestamp

try this:

ren "File 1-1" "File 1 - %date:/=-% %time::=-%"

MySQLi prepared statements error reporting

Not sure if this answers your question or not. Sorry if not

To get the error reported from the mysql database about your query you need to use your connection object as the focus.

so:

echo $mysqliDatabaseConnection->error

would echo the error being sent from mysql about your query.

Hope that helps

failed to find target with hash string android-23

In Android Studio File -> Invalidate Caches/Restart solved the issue for me.

How to add constraints programmatically using Swift

If you find the above to be ugly. You should consider using a DSL for constraints. Such as SnapKit Makes constraint API much more user-friendly

view.snp.makeConstraints { make in
    make.edges.equalToSuperview()
}

How to set a JavaScript breakpoint from code in Chrome?

There are many ways to debug JavaScript code. Following two approaches are widely used to debug JavaScript via code

  1. Using console.log() to print out the values in the browser console. (This will help you understand the values at certain points of your code)

  2. Debugger keyword. Add debugger; to the locations you want to debug, and open the browser's developer console and navigate to the sources tab.

For more tools and ways in which you debug JavaScript Code, are given in this link by W3School.

In SQL how to compare date values?

Your problem may be that you are dealing with DATETIME data, not just dates. If a row has a mydate that is '2008-11-25 09:30 AM', then your WHERE mydate<='2008-11-25'; is not going to return that row. '2008-11-25' has an implied time of 00:00 (midnight), so even though the date part is the same, they are not equal, and mydate is larger.

If you use < '2008-11-26' instead of <= '2008-11-25', that would work. The Datediff method works because it compares just the date portion, and ignores the times.

javascript: using a condition in switch case

This works:

switch (true) {
    case liCount == 0:
        setLayoutState('start');
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;
    case liCount<=5 && liCount>0:
        setLayoutState('upload1Row');
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;
    case liCount<=10 && liCount>5:
        setLayoutState('upload2Rows');
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;
    case liCount>10:
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;                  
}

A previous version of this answer considered the parentheses to be the culprit. In truth, the parentheses are irrelevant here - the only thing necessary is switch(true){...} and for your case expressions to evaluate to booleans.

It works because, the value we give to the switch is used as the basis to compare against. Consequently, the case expressions, also evaluating to booleans will determine which case is run. Could also turn this around, and pass switch(false){..} and have the desired expressions evaluate to false instead of true.. but personally prefer dealing with conditions that evaluate to truthyness. However, it does work too, so worth keeping in mind to understand what it is doing.

Eg: if liCount is 3, the first comparison is true === (liCount == 0), meaning the first case is false. The switch then moves on to the next case true === (liCount<=5 && liCount>0). This expression evaluates to true, meaning this case is run, and terminates at the break. I've added parentheses here to make it clearer, but they are optional, depending on the complexity of your expression.

It's pretty simple, and a neat way (if it fits with what you are trying to do) of handling a long series of conditions, where perhaps a long series of ìf() ... else if() ... else if () ... might introduce a lot of visual noise or fragility.

Use with caution, because it is a non-standard pattern, despite being valid code.

How do you remove an array element in a foreach loop?

A better solution is to use the array_filter function:

$display_related_tags =
    array_filter($display_related_tags, function($e) use($found_tag){
        return $e != $found_tag['name'];
    });

As the php documentation reads:

As foreach relies on the internal array pointer in PHP 5, changing it within the loop may lead to unexpected behavior.

In PHP 7, foreach does not use the internal array pointer.

How to use onClick() or onSelect() on option tag in a JSP page?

If you need to change the value of another field, you can use this:

<input type="hidden" id="mainvalue" name="mainvalue" value="0">
<select onChange="document.getElementById('mainvalue').value = this.value;">
<option value="0">option 1</option>
<option value="1">option 2</option>
</select>

Complex CSS selector for parent of active child

I had the same problem with Drupal. Given the limitations of CSS, the way to get this working is to add the "active" class to the parent elements when the menu HTML is generated. There's a good discussion of this at http://drupal.org/node/219804, the upshot of which is that this functionality has been rolled in to version 6.x-2.x of the nicemenus module. As this is still in development, I've backported the patch to 6.x-1.3 at http://drupal.org/node/465738 so that I can continue to use the production-ready version of the module.

Default values and initialization in Java

In the first case you are declaring "int a" as a local variable(as declared inside a method) and local varible do not get default value.

But instance variable are given default value both for static and non-static.

Default value for instance variable:

int = 0

float,double = 0.0

reference variable = null

char = 0 (space character)

boolean = false

Calling jQuery method from onClick attribute in HTML

I don't think there's any reason to add this function to JQuery's namespace. Why not just define the method by itself:

function showMessage(msg) {
   alert(msg);
};

<input type="button" value="ahaha" onclick="showMessage('msg');" />

UPDATE: With a small change to how your method is defined I can get it to work:

<html>
<head>
 <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
 <script language="javascript">
    // define the function within the global scope
    $.fn.MessageBox = function(msg) {
        alert(msg);
    };

    // or, if you want to encapsulate variables within the plugin
    (function($) {
        $.fn.MessageBoxScoped = function(msg) {
            alert(msg);
        };
    })(jQuery); //<-- make sure you pass jQuery into the $ parameter
 </script>
</head>
<body>
 <div class="Title">Welcome!</div>
 <input type="button" value="ahaha" id="test" onClick="$(this).MessageBox('msg');" />
</body>
</html>

Count number of lines in a git repository

The answer by Carl Norum assumes there are no files with spaces, one of the characters of IFS with the others being tab and newline. The solution would be to terminate the line with a NULL byte.

 git ls-files -z | xargs -0 cat | wc -l

Convert varchar dd/mm/yyyy to dd/mm/yyyy datetime

If you want to return a format mm/dd/yyyy, then use 101 instead of 103: CONVERT(VARCHAR(10), [MyDate], 101)

"Post Image data using POSTMAN"

Now you can hover the key input and select "file", which will give you a file selector in the value column:

enter image description here

How to convert a GUID to a string in C#?

Guid guidId = Guid.Parse("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx");
string guidValue = guidId.ToString("D"); //return with hyphens

Spark specify multiple column conditions for dataframe join

In Pyspark you can simply specify each condition separately:

val Lead_all = Leads.join(Utm_Master,  
    (Leaddetails.LeadSource == Utm_Master.LeadSource) &
    (Leaddetails.Utm_Source == Utm_Master.Utm_Source) &
    (Leaddetails.Utm_Medium == Utm_Master.Utm_Medium) &
    (Leaddetails.Utm_Campaign == Utm_Master.Utm_Campaign))

Just be sure to use operators and parenthesis correctly.

jQuery - select all text from a textarea

Better way, with solution to tab and chrome problem and new jquery way

$("#element").on("focus keyup", function(e){

        var keycode = e.keyCode ? e.keyCode : e.which ? e.which : e.charCode;
        if(keycode === 9 || !keycode){
            // Hacemos select
            var $this = $(this);
            $this.select();

            // Para Chrome's que da problema
            $this.on("mouseup", function() {
                // Unbindeamos el mouseup
                $this.off("mouseup");
                return false;
            });
        }
    });

How to negate code in "if" statement block in JavaScript -JQuery like 'if not then..'

You can use the Logical NOT ! operator:

if (!$(this).parent().next().is('ul')){

Or equivalently (see comments below):

if (! ($(this).parent().next().is('ul'))){

For more information, see the Logical Operators section of the MDN docs.

Delete a row in DataGridView Control in VB.NET

If dgv(11, dgv.CurrentRow.Index).Selected = True Then
    dgv.Rows.RemoveAt(dgv.CurrentRow.Index)
Else
    Exit Sub
End If

How to show all of columns name on pandas dataframe?

I know it is a repetition but I always end up copy pasting and modifying YOLO's answer:

pd.set_option('display.max_columns', 500)
pd.set_option('display.max_rows', 500)

Java: Clear the console

You need to use control characters as backslash (\b) and carriage return (\r). It come disabled by default, but the Console view can interpret these controls.

Windows>Preferences and Run/Debug > Console and select Interpret ASCII control characteres to enabled it

Console preferences in Eclipse

After these configurations, you can manage your console with control characters like:

\t - tab.

\b - backspace (a step backward in the text or deletion of a single character).

\n - new line.

\r - carriage return. ()

\f - form feed.

eclipse console clear animation

More information at: https://www.eclipse.org/eclipse/news/4.14/platform.php

C++ Erase vector element by value rather than by position?

You can use std::find to get an iterator to a value:

#include <algorithm>
std::vector<int>::iterator position = std::find(myVector.begin(), myVector.end(), 8);
if (position != myVector.end()) // == myVector.end() means the element was not found
    myVector.erase(position);

getting the reason why websockets closed with close code 1006

This may be your websocket URL you are using in device are not same(You are hitting different websocket URL from android/iphonedevice )

Why do I get the error "Unsafe code may only appear if compiling with /unsafe"?

Probably because you're using unsafe code.

Are you doing something with pointers or unmanaged assemblies somewhere?

select certain columns of a data table

DataView dv = new DataView(Your DataTable);

DataTable dt = dv.ToTable(true, "Your Specific Column Name");

The dt contains only selected column values.

Oracle SQL Developer - tables cannot be seen

3.1 didn't matter for me.

It took me a while, but I managed to find the 2.1 release to try that out here: http://www.oracle.com/technetwork/testcontent/index21-ea1-095147.html

1.2 http://www.oracle.com/technetwork/testcontent/index-archive12-101280.html

That doesn't work either though, still no tables so it looks like something with permission.

How to read an external properties file in Maven

This answer to a similar question describes how to extend the properties plugin so it can use a remote descriptor for the properties file. The descriptor is basically a jar artifact containing a properties file (the properties file is included under src/main/resources).

The descriptor is added as a dependency to the extended properties plugin so it is on the plugin's classpath. The plugin will search the classpath for the properties file, read the file''s contents into a Properties instance, and apply those properties to the project's configuration so they can be used elsewhere.

How to get the current date and time of your timezone in Java?

With the java.time classes built into Java 8 and later:

public static void main(String[] args) {
        LocalDateTime localNow = LocalDateTime.now(TimeZone.getTimeZone("Europe/Madrid").toZoneId());
        System.out.println(localNow);
        // Prints current time of given zone without zone information : 2016-04-28T15:41:17.611
        ZonedDateTime zoneNow = ZonedDateTime.now(TimeZone.getTimeZone("Europe/Madrid").toZoneId());
        System.out.println(zoneNow);
        // Prints current time of given zone with zone information : 2016-04-28T15:41:17.627+02:00[Europe/Madrid]
    }

Getter and Setter?

Encapsulation is important in any OO language, popularity has nothing to do with it. In dynamically typed languages, like PHP, it is especially useful because there is little ways to ensure a property is of a specific type without using setters.

In PHP, this works:

class Foo {
   public $bar; // should be an integer
}
$foo = new Foo;
$foo->bar = "string";

In Java, it doesn't:

class Foo {
   public int bar;
}
Foo myFoo = new Foo();
myFoo.bar = "string"; // error

Using magic methods (__get and __set) also works, but only when accessing a property that has lower visibility than the current scope can access. It can easily give you headaches when trying to debug, if it is not used properly.

curl Failed to connect to localhost port 80

In my case, the file ~/.curlrc had a wrong proxy configured.

Best way to generate xml?

I've tried a some of the solutions in this thread, and unfortunately, I found some of them to be cumbersome (i.e. requiring excessive effort when doing something non-trivial) and inelegant. Consequently, I thought I'd throw my preferred solution, web2py HTML helper objects, into the mix.

First, install the the standalone web2py module:

pip install web2py

Unfortunately, the above installs an extremely antiquated version of web2py, but it'll be good enough for this example. The updated source is here.

Import web2py HTML helper objects documented here.

from gluon.html import *

Now, you can use web2py helpers to generate XML/HTML.

words = ['this', 'is', 'my', 'item', 'list']
# helper function
create_item = lambda idx, word: LI(word, _id = 'item_%s' % idx, _class = 'item')
# create the HTML
items = [create_item(idx, word) for idx,word in enumerate(words)]
ul = UL(items, _id = 'my_item_list', _class = 'item_list')
my_div = DIV(ul, _class = 'container')

>>> my_div

<gluon.html.DIV object at 0x00000000039DEAC8>

>>> my_div.xml()
# I added the line breaks for clarity
<div class="container">
   <ul class="item_list" id="my_item_list">
      <li class="item" id="item_0">this</li>
      <li class="item" id="item_1">is</li>
      <li class="item" id="item_2">my</li>
      <li class="item" id="item_3">item</li>
      <li class="item" id="item_4">list</li>
   </ul>
</div>

composer laravel create project

I also had same problem then I found this on there documentation page

So if you want to create a project by name of test_laravel in directory /Applications/MAMP/htdocs/ then what you need to do is

go to your project parent directory

cd /Applications/MAMP/htdocs

and fire this command

composer create-project laravel/laravel test_laravel --prefer-dist

that's it, this is really easy and it also creates Application Key automatically for you

Compilation error: stray ‘\302’ in program etc

It's perhaps because you copied code from net ( from a site which has perhaps not an ASCII encoded page, but UTF-8 encoded page), so you can convert the code to ASCII from this site :

"http://www.percederberg.net/tools/text_converter.html"

There you can either detect errors manually by converting it back to UTF-8, or you can automatically convert it to ASCII and remove all the stray characters.

Get MD5 hash of big files in Python

Break the file into 8192-byte chunks (or some other multiple of 128 bytes) and feed them to MD5 consecutively using update().

This takes advantage of the fact that MD5 has 128-byte digest blocks (8192 is 128×64). Since you're not reading the entire file into memory, this won't use much more than 8192 bytes of memory.

In Python 3.8+ you can do

import hashlib
with open("your_filename.txt", "rb") as f:
    file_hash = hashlib.md5()
    while chunk := f.read(8192):
        file_hash.update(chunk)
print(file_hash.digest())
print(file_hash.hexdigest())  # to get a printable str instead of bytes

How do I output text without a newline in PowerShell?

$host.UI.Write('Enabling feature XYZ.......')
Enable-SPFeature...
$host.UI.WriteLine('Done')

Letsencrypt add domain to existing certificate

You can replace the certificate by just running the certbot again with ./certbot-auto certonly

You will be prompted with this message if you try to generate a certificate for a domain that you have already covered by an existing certificate:

-------------------------------------------------------------------------------
You have an existing certificate that contains a portion of the domains you
requested (ref: /etc/letsencrypt/renewal/<domain>.conf)

It contains these names: <domain>

You requested these names for the new certificate: <domain>,
<the domain you want to add to the cert>.

Do you want to expand and replace this existing certificate with the new
certificate?
-------------------------------------------------------------------------------

Just chose Expand and replace it.

jQuery - trapping tab select event

Simply use the on click event for tab shown.

$(document).on('shown.bs.tab', 'a[href="#tab"]', function (){
});

How to "wait" a Thread in Android

You need the sleep method of the Thread class.

public static void sleep (long time)

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

Parameters

time The time to sleep in milliseconds.

Algorithm to calculate the number of divisors of a given number

@Yasky

Your divisors function has a bug in that it does not work correctly for perfect squares.

Try:

int divisors(int x) {
    int limit = x;
    int numberOfDivisors = 0;

    if (x == 1) return 1;

    for (int i = 1; i < limit; ++i) {
        if (x % i == 0) {
            limit = x / i;
            if (limit != i) {
                numberOfDivisors++;
            }
            numberOfDivisors++;
        }
    }

    return numberOfDivisors;
}

How to change the port of Tomcat from 8080 to 80?

1) Go to conf folder in tomcat installation directory

 e.g. C:\Tomcat 6.0\conf\

2) Edit following tag in server.xml file

<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443"/>

3) Change the port=8080 value to port=80

4) Save file.

5) Stop your Tomcat and restart it.

CSS Animation and Display None

There are a few answers already, but here is my solution:

I use opacity: 0 and visibility: hidden. To make sure that visibility is set before the animation, we have to set the right delays.

I use http://lesshat.com to simplify the demo, for use without this just add the browser prefixes.

(e.g. -webkit-transition-duration: 0, 200ms;)

.fadeInOut {
    .transition-duration(0, 200ms);
    .transition-property(visibility, opacity);
    .transition-delay(0);

    &.hidden {
        visibility: hidden;
        .opacity(0);
        .transition-duration(200ms, 0);
        .transition-property(opacity, visibility);
        .transition-delay(0, 200ms);
    }
}

So as soon as you add the class hidden to your element, it will fade out.

Spring @Value is not resolving to value from property file

Have a read of pedjaradenkovic's comment.

Further to the link he provides, the reason this isn't working is that @Value processing requires a PropertySourcesPlaceholderConfigurer instead of a PropertyPlaceholderConfigurer.

How to output loop.counter in python jinja template?

in python:

env = Environment(loader=FileSystemLoader("templates"))
env.globals["enumerate"] = enumerate

in template:

{% for k,v in enumerate(list) %}
{% endfor %}

Hide axis and gridlines Highcharts

i managed to turn off mine with just

       lineColor: 'transparent',
       tickLength: 0

How to stop a PowerShell script on the first error?

A slight modification to the answer from @alastairtree:

function Invoke-Call {
    param (
        [scriptblock]$ScriptBlock,
        [string]$ErrorAction = $ErrorActionPreference
    )
    & @ScriptBlock
    if (($lastexitcode -ne 0) -and $ErrorAction -eq "Stop") {
        exit $lastexitcode
    }
}

Invoke-Call -ScriptBlock { dotnet build . } -ErrorAction Stop

The key differences here are:

  1. it uses the Verb-Noun (mimicing Invoke-Command)
  2. implies that it uses the call operator under the covers
  3. mimics -ErrorAction behavior from built in cmdlets
  4. exits with same exit code rather than throwing exception with new message

How can I limit ngFor repeat to some number of items in Angular?

 <div *ngFor="let item of list;trackBy: trackByFunc" >
   {{item.value}}
 </div>

In your ts file

 trackByFunc(index, item){
    return item ? item.id : undefined;
  }

How to get current time with jQuery

You may try like this:

new Date($.now());

Also using Javascript you can do like this:

_x000D_
_x000D_
var dt = new Date();_x000D_
var time = dt.getHours() + ":" + dt.getMinutes() + ":" + dt.getSeconds();_x000D_
document.write(time);
_x000D_
_x000D_
_x000D_

How to delete history of last 10 commands in shell?

Maybe will be useful for someone.
When you login to any user of any console/terminal history of your current session exists only in some "buffer" which flushes to ~/.bash_history on your logout.
So, to keep things secret you can just:
history -r && exit
and you will be logged out with all your session's (and only) history cleared ;)

loop through json array jquery

I dont think youre returning json object from server. just a string.

you need the dataType of the return object to be json

do <something> N times (declarative syntax)

There is a fantastic library called Ramda, which is similar to Underscore and Lodash, but is more powerful.

const R = require('ramda');

R.call(R.times(() => {
    console.log('do something')
}), 5);

Ramda contains plenty of useful functions. See Ramda documentation

inherit from two classes in C#

Do you mean you want Class C to be the base class for A & B in that case.

public abstract class C
{
    public abstract void Method1();

    public abstract void Method2();
}

public class A : C
{
    public override void Method1()
    {
        throw new NotImplementedException();
    }

    public override void Method2()
    {
        throw new NotImplementedException();
    }
}


public class B : C
{
    public override void Method1()
    {
        throw new NotImplementedException();
    }

    public override void Method2()
    {
        throw new NotImplementedException();
    }
}

PHP - include a php file and also send query parameters

You can use $GLOBALS to solve this issue as well.

$myvar = "Hey";

include ("test.php");


echo $GLOBALS["myvar"];

How to get value by class name in JavaScript or jquery?

If you get the the text inside the element use

Text()

$(".element-classname").text();

In your code:

$('.HOEnZb').text();

if you want get all the data including html Tags use:

html()

 $(".element-classname").html();

In your code:

$('.HOEnZb').html();

Hope it helps:)

Minimum and maximum date

From the spec, §15.9.1.1:

A Date object contains a Number indicating a particular instant in time to within a millisecond. Such a Number is called a time value. A time value may also be NaN, indicating that the Date object does not represent a specific instant of time.

Time is measured in ECMAScript in milliseconds since 01 January, 1970 UTC. In time values leap seconds are ignored. It is assumed that there are exactly 86,400,000 milliseconds per day. ECMAScript Number values can represent all integers from –9,007,199,254,740,992 to 9,007,199,254,740,992; this range suffices to measure times to millisecond precision for any instant that is within approximately 285,616 years, either forward or backward, from 01 January, 1970 UTC.

The actual range of times supported by ECMAScript Date objects is slightly smaller: exactly –100,000,000 days to 100,000,000 days measured relative to midnight at the beginning of 01 January, 1970 UTC. This gives a range of 8,640,000,000,000,000 milliseconds to either side of 01 January, 1970 UTC.

The exact moment of midnight at the beginning of 01 January, 1970 UTC is represented by the value +0.

The third paragraph being the most relevant. Based on that paragraph, we can get the precise earliest date per spec from new Date(-8640000000000000), which is Tuesday, April 20th, 271,821 BCE (BCE = Before Common Era, e.g., the year -271,821).

How to change language of app when user selects language?

Good solutions explained pretty well here. But Here is one more.

Create your own CustomContextWrapper class extending ContextWrapper and use it to change Locale setting for the complete application. Here is a GIST with usage.

And then call the CustomContextWrapper with saved locale identifier e.g. 'hi' for Hindi language in activity lifecycle method attachBaseContext. Usage here:

@Override
protected void attachBaseContext(Context newBase) {
    // fetch from shared preference also save the same when applying. Default here is en = English
    String language = MyPreferenceUtil.getInstance().getString("saved_locale", "en");
    super.attachBaseContext(MyContextWrapper.wrap(newBase, language));
}

regex.test V.S. string.match to know if a string matches a regular expression

This is my benchmark results benchmark results

test 4,267,740 ops/sec ±1.32% (60 runs sampled)

exec 3,649,719 ops/sec ±2.51% (60 runs sampled)

match 3,623,125 ops/sec ±1.85% (62 runs sampled)

indexOf 6,230,325 ops/sec ±0.95% (62 runs sampled)

test method is faster than the match method, but the fastest method is the indexOf

gcc: undefined reference to

However, avpicture_get_size is defined.

No, as the header (<libavcodec/avcodec.h>) just declares it.

The definition is in the library itself.

So you might like to add the linker option to link libavcodec when invoking gcc:

-lavcodec

Please also note that libraries need to be specified on the command line after the files needing them:

gcc -I$HOME/ffmpeg/include program.c -lavcodec

Not like this:

gcc -lavcodec -I$HOME/ffmpeg/include program.c

Referring to Wyzard's comment, the complete command might look like this:

gcc -I$HOME/ffmpeg/include program.c -L$HOME/ffmpeg/lib -lavcodec

For libraries not stored in the linkers standard location the option -L specifies an additional search path to lookup libraries specified using the -l option, that is libavcodec.x.y.z in this case.


For a detailed reference on GCC's linker option, please read here.

How to use a filter in a controller?

It seems nobody has mentioned that you can use a function as arg2 in $filter('filtername')(arg1,arg2);

For example:

$scope.filteredItems = $filter('filter')(items, function(item){return item.Price>50;});

Get git branch name in Jenkins Pipeline/Jenkinsfile

FWIW the only thing that worked for me in PR builds was ${CHANGE_BRANCH}

(may not work on master, haven't seen that yet)

Get user location by IP address

you can

using System.Net;
using System.IO;
using Newtonsoft.Json.Linq;
public ActionResult geoPlugin()
    {

        var url = "http://freegeoip.net/json/";
        var request = System.Net.WebRequest.Create(url);

        using (WebResponse wrs = request.GetResponse())
        using (Stream stream = wrs.GetResponseStream())
        using (StreamReader reader = new StreamReader(stream))
        {
            string json = reader.ReadToEnd();
            var obj = JObject.Parse(json);
            var City = (string)obj["city"];
            // - For Country = (string)obj["region_name"];                    
            //- For  CountryCode = (string)obj["country_code"];
            Session["CurrentRegionName"]= (string)obj["country_name"];
            Session["CurrentRegion"] = (string)obj["country_code"];
        }
        return RedirectToAction("Index");
    }

RS256 vs HS256: What's the difference?

There is a difference in performance.

Simply put HS256 is about 1 order of magnitude faster than RS256 for verification but about 2 orders of magnitude faster than RS256 for issuing (signing).

 640,251  91,464.3 ops/s
  86,123  12,303.3 ops/s (RS256 verify)
   7,046   1,006.5 ops/s (RS256 sign)

Don't get hung up on the actual numbers, just think of them with respect of each other.

[Program.cs]

class Program
{
    static void Main(string[] args)
    {
        foreach (var duration in new[] { 1, 3, 5, 7 })
        {
            var t = TimeSpan.FromSeconds(duration);

            byte[] publicKey, privateKey;

            using (var rsa = new RSACryptoServiceProvider())
            {
                publicKey = rsa.ExportCspBlob(false);
                privateKey = rsa.ExportCspBlob(true);
            }

            byte[] key = new byte[64];

            using (var rng = new RNGCryptoServiceProvider())
            {
                rng.GetBytes(key);
            }

            var s1 = new Stopwatch();
            var n1 = 0;

            using (var hs256 = new HMACSHA256(key))
            {
                while (s1.Elapsed < t)
                {
                    s1.Start();
                    var hash = hs256.ComputeHash(privateKey);
                    s1.Stop();
                    n1++;
                }
            }

            byte[] sign;

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportCspBlob(privateKey);

                sign = rsa.SignData(privateKey, "SHA256");
            }

            var s2 = new Stopwatch();
            var n2 = 0;

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportCspBlob(publicKey);

                while (s2.Elapsed < t)
                {
                    s2.Start();
                    var success = rsa.VerifyData(privateKey, "SHA256", sign);
                    s2.Stop();
                    n2++;
                }
            }

            var s3 = new Stopwatch();
            var n3 = 0;

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportCspBlob(privateKey);

                while (s3.Elapsed < t)
                {
                    s3.Start();
                    rsa.SignData(privateKey, "SHA256");
                    s3.Stop();
                    n3++;
                }
            }

            Console.WriteLine($"{s1.Elapsed.TotalSeconds:0} {n1,7:N0} {n1 / s1.Elapsed.TotalSeconds,9:N1} ops/s");
            Console.WriteLine($"{s2.Elapsed.TotalSeconds:0} {n2,7:N0} {n2 / s2.Elapsed.TotalSeconds,9:N1} ops/s");
            Console.WriteLine($"{s3.Elapsed.TotalSeconds:0} {n3,7:N0} {n3 / s3.Elapsed.TotalSeconds,9:N1} ops/s");

            Console.WriteLine($"RS256 is {(n1 / s1.Elapsed.TotalSeconds) / (n2 / s2.Elapsed.TotalSeconds),9:N1}x slower (verify)");
            Console.WriteLine($"RS256 is {(n1 / s1.Elapsed.TotalSeconds) / (n3 / s3.Elapsed.TotalSeconds),9:N1}x slower (issue)");

            // RS256 is about 7.5x slower, but it can still do over 10K ops per sec.
        }
    }
}

What is newline character -- '\n'

I see a lot of sed answers, but none for vim. To be fair, vim's treatment of newline characters is a little confusing. Search for \n but replace with \r. I recommend RTFM: :help pattern in general and :help NL-used-for-Nul in particular.

To do what you want with a :substitute command,

:%s/\_$/\r

although I think most people would use something like

:g/^/put=''

for the same effect.

Here is a way to find the answer for yourself. Run your file through xxd, which is part of the standard vim distribution.

:%!xxd

You get

0000000: 4361 6c69 666f 726e 6961 0a4d 6173 7361  California.Massa
0000010: 6368 7573 6574 7473 0a41 7269 7a6f 6e61  chusetts.Arizona
0000020: 0a                                       .

This shows that 46 is the hex code for C, 61 is the code for a, and so on. In particular, 0a (decimal 10) is the code for \n. Just for kicks, try

:set ff=dos

before filtering through xxd. You will see 0d0a (CRLF) as the line terminator.

:help /\_$
:help :g
:help :put
:help :!
:help 23.4

When should I really use noexcept?

As I keep repeating these days: semantics first.

Adding noexcept, noexcept(true) and noexcept(false) is first and foremost about semantics. It only incidentally condition a number of possible optimizations.

As a programmer reading code, the presence of noexcept is akin to that of const: it helps me better grok what may or may not happen. Therefore, it is worthwhile spending some time thinking about whether or not you know if the function will throw. For a reminder, any kind of dynamic memory allocation may throw.


Okay, now on to the possible optimizations.

The most obvious optimizations are actually performed in the libraries. C++11 provides a number of traits that allows knowing whether a function is noexcept or not, and the Standard Library implementation themselves will use those traits to favor noexcept operations on the user-defined objects they manipulate, if possible. Such as move semantics.

The compiler may only shave a bit of fat (perhaps) from the exception handling data, because it has to take into account the fact that you may have lied. If a function marked noexcept does throw, then std::terminate is called.

These semantics were chosen for two reasons:

  • immediately benefiting from noexcept even when dependencies do not use it already (backward compatibility)
  • allowing the specification of noexcept when calling functions that may theoretically throw, but are not expected to for the given arguments

Passing std::string by Value or Reference

Check this answer for C++11. Basically, if you pass an lvalue the rvalue reference

From this article:

void f1(String s) {
    vector<String> v;
    v.push_back(std::move(s));
}
void f2(const String &s) {
    vector<String> v;
    v.push_back(s);
}

"For lvalue argument, ‘f1’ has one extra copy to pass the argument because it is by-value, while ‘f2’ has one extra copy to call push_back. So no difference; for rvalue argument, the compiler has to create a temporary ‘String(L“”)’ and pass the temporary to ‘f1’ or ‘f2’ anyway. Because ‘f2’ can take advantage of move ctor when the argument is a temporary (which is an rvalue), the costs to pass the argument are the same now for ‘f1’ and ‘f2’."

Continuing: " This means in C++11 we can get better performance by using pass-by-value approach when:

  1. The parameter type supports move semantics - All standard library components do in C++11
  2. The cost of move constructor is much cheaper than the copy constructor (both the time and stack usage).
  3. Inside the function, the parameter type will be passed to another function or operation which supports both copy and move.
  4. It is common to pass a temporary as the argument - You can organize you code to do this more.

"

OTOH, for C++98 it is best to pass by reference - less data gets copied around. Passing const or non const depend of whether you need to change the argument or not.

Transparent scrollbar with css

if you don't have any content with 100% width, you can set the background color of the track to the same color of the body's background

Rails migration for change column

Another way to change data type using migration

step1: You need to remove the faulted data type field name using migration

ex:

rails g migration RemoveFieldNameFromTableName field_name:data_type

Here don't forget to specify data type for your field

Step 2: Now you can add field with correct data type

ex:

rails g migration AddFieldNameToTableName field_name:data_type

That's it, now your table will added with correct data type field, Happy ruby coding!!

How to Alter Constraint

You can not alter constraints ever but you can drop them and then recreate.

Have look on this

ALTER TABLE your_table DROP CONSTRAINT ACTIVEPROG_FKEY1;

and then recreate it with ON DELETE CASCADE like this

ALTER TABLE your_table
add CONSTRAINT ACTIVEPROG_FKEY1 FOREIGN KEY(ActiveProgCode) REFERENCES PROGRAM(ActiveProgCode)
    ON DELETE CASCADE;

hope this help

What does a just-in-time (JIT) compiler do?

You have code that is compliled into some IL (intermediate language). When you run your program, the computer doesn't understand this code. It only understands native code. So the JIT compiler compiles your IL into native code on the fly. It does this at the method level.

In PowerShell, how can I test if a variable holds a numeric value?

PS> Add-Type -Assembly Microsoft.VisualBasic
PS> [Microsoft.VisualBasic.Information]::IsNumeric(1.5)
True

http://msdn.microsoft.com/en-us/library/microsoft.visualbasic.information.isnumeric.aspx

Loop through checkboxes and count each one checked or unchecked

I don't think enough time was paid attention to the schema considerations brought up in the original post. So, here is something to consider for any newbies.

Let's say you went ahead and built this solution. All of your menial values are conctenated into a single value and stored in the database. You are indeed saving [a little] space in your database and some time coding.

Now let's consider that you must perform the frequent and easy task of adding a new checkbox between the current checkboxes 3 & 4. Your development manager, customer, whatever expects this to be a simple change.

So you add the checkbox to the UI (the easy part). Your looping code would already concatenate the values no matter how many checkboxes. You also figure your database field is just a varchar or other string type so it should be fine as well.

What happens when customers or you try to view the data from before the change? You're essentially serializing from left to right. However, now the values after 3 are all off by 1 character. What are you going to do with all of your existing data? Are you going write an application, pull it all back out of the database, process it to add in a default value for the new question position and then store it all back in the database? What happens when you have several new values a week or month apart? What if you move the locations and jQuery processes them in a different order? All your data is hosed and has to be reprocessed again to rearrange it.

The whole concept of NOT providing a tight key-value relationship is ludacris and will wind up getting you into trouble sooner rather than later. For those of you considering this, please don't. The other suggestions for schema changes are fine. Use a child table, more fields in the main table, a question-answer table, etc. Just don't store non-labeled data when the structure of that data is subject to change.

How to get all privileges back to the root user in MySQL?

Log in as root, then run the following MySQL commands:

GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost';
FLUSH PRIVILEGES;

Custom Card Shape Flutter SDK

An Alternative Solution to the above

Card(
  shape: RoundedRectangleBorder(
     borderRadius: BorderRadius.only(topLeft: Radius.circular(20), topRight: Radius.circular(20))),
  color: Colors.white,
  child: ...
)

You can use BorderRadius.only() to customize the corners you wish to manage.

How to concatenate columns in a Postgres SELECT?

With string type columns like character(2) (as you mentioned later), the displayed concatenation just works because, quoting the manual:

[...] the string concatenation operator (||) accepts non-string input, so long as at least one input is of a string type, as shown in Table 9.8. For other cases, insert an explicit coercion to text [...]

Bold emphasis mine. The 2nd example (select a||', '||b from foo) works for any data types since the untyped string literal ', ' defaults to type text making the whole expression valid in any case.

For non-string data types, you can "fix" the 1st statement by casting at least one argument to text. (Any type can be cast to text):

SELECT a::text || b AS ab FROM foo;

Judging from your own answer, "does not work" was supposed to mean "returns NULL". The result of anything concatenated to NULL is NULL. If NULL values can be involved and the result shall not be NULL, use concat_ws() to concatenate any number of values (Postgres 9.1 or later):

SELECT concat_ws(', ', a, b) AS ab FROM foo;

Or concat() if you don't need separators:

SELECT concat(a, b) AS ab FROM foo;

No need for type casts here since both functions take "any" input and work with text representations.

More details (and why COALESCE is a poor substitute) in this related answer:

Regarding update in the comment

+ is not a valid operator for string concatenation in Postgres (or standard SQL). It's a private idea of Microsoft to add this to their products.

There is hardly any good reason to use character(n) (synonym: char(n)). Use text or varchar. Details:

Getting a list of files in a directory with a glob

Swift 5 for cocoa

        // Getting the Contents of a Directory in a Single Batch Operation

        let bundleRoot = Bundle.main.bundlePath
        let url = URL(string: bundleRoot)
        let properties: [URLResourceKey] = [ URLResourceKey.localizedNameKey, URLResourceKey.creationDateKey, URLResourceKey.localizedTypeDescriptionKey]
        if let src = url{
            do {
                let paths = try FileManager.default.contentsOfDirectory(at: src, includingPropertiesForKeys: properties, options: [])

                for p in paths {
                     if p.hasSuffix(".data"){
                           print("File Path is: \(p)")
                     }
                }

            } catch  {  }
        }