Programs & Examples On #Blueprint

Blueprint is a CSS framework that comes with an easy-to-use grid, sensible typography, useful plugins, and a stylesheet for printing.

Android - how to make a scrollable constraintlayout?

Please use below solution it has taken my lots of time to fix.

Enjoy your time :)

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<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white"
    >

    <ScrollView
        android:id="@+id/mainScroll"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        android:fillViewport="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentStart="true">
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">


            <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                android:layout_alignParentStart="true"
                android:layout_alignParentTop="true"
                android:layout_alignParentBottom="true"
                android:layout_alignParentEnd="true"
                >

            </android.support.constraint.ConstraintLayout>

        </RelativeLayout>
    </ScrollView>
</RelativeLayout>
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Use Exactly like this u will definitely find your solution...

How to fix error Base table or view not found: 1146 Table laravel relationship table?

You can add this in Post Model,

public function categories()
{
 return $this->belongsToMany('App\Category','category_post','post_id','category_id');                 
}

category_post indicate the table you want to use.
post_id indicate the column where you want to store the posts id.
category_id indicate the column where you want to store the categories id.

Laravel migration default value

Might be a little too late to the party, but hope this helps someone with similar issue.

The reason why your default value doesnt't work is because the migration file sets up the default value in your database (MySQL or PostgreSQL or whatever), and not in your Laravel application.

Let me illustrate with an example.

This line means Laravel is generating a new Book instance, as specified in your model. The new Book object will have properties according to the table associated with the model. Up until this point, nothing is written on the database.

$book = new Book();

Now the following lines are setting up the values of each property of the Book object. Same still, nothing is written on the database yet.

$book->author = 'Test'
$book->title = 'Test'

This line is the one writing to the database. After passing on the object to the database, then the empty fields will be filled by the database (may be default value, may be null, or whatever you specify on your migration file).

$book->save();

And thus, the default value will not pop up before you save it to the database.

But, that is not enough. If you try to access $book->price, it will still be null (or 0, i'm not sure). Saving it is only adding the defaults to the record in the database, and it won't affect the Object you are carrying around.

So, to get the instance with filled-in default values, you have to re-fetch the instance. You may use the

Book::find($book->id);

Or, a more sophisticated way by refreshing the instance

$book->refresh();

And then, the next time you try to access the object, it will be filled with the default values.

Laravel migration table field's type change

Not really an answer, but just a note about ->change():

Only the following column types can be "changed": bigInteger, binary, boolean, date, dateTime, dateTimeTz, decimal, integer, json, longText, mediumText, smallInteger, string, text, time, unsignedBigInteger, unsignedInteger and unsignedSmallInteger.

https://laravel.com/docs/5.8/migrations#modifying-columns

If your column isn't one of these you will need to either drop the column or use the alter statement as mentioned in other answers.

Artisan, creating tables in database

In order to give a value in the table, we need to give a command:

php artisan make:migration create_users_table

and after then this command line

php artisan migrate

......

How can I rename column in laravel using migration?

Renaming Columns (Laravel 5.x)

To rename a column, you may use the renameColumn method on the Schema builder. *Before renaming a column, be sure to add the doctrine/dbal dependency to your composer.json file.*

Or you can simply required the package using composer...

composer require doctrine/dbal

Source: https://laravel.com/docs/5.0/schema#renaming-columns

Note: Use make:migration and not migrate:make for Laravel 5.x

Laravel Migration table already exists, but I want to add new not the older

I inherited some real bad code from someone who wasn't using migrations!?, so manually pasted the filenames into the migrations, forgetting to remove the trailing .php

So that caused the 'table exists' error despite the filename and migration matching.

2018_05_07_142737_create_users_table.php - WRONG 2018_05_07_142737_create_users_table - CORRECT

Laravel Migration Change to Make a Column Nullable

If you happens to change the columns and stumbled on

'Doctrine\DBAL\Driver\PDOMySql\Driver' not found

then just install

composer require doctrine/dbal

Laravel migration: unique key is too long, even if specified

SOLUTION:

First change the defaultStringLength to 191, in the app\Providers\AppServiceProvider.php:

public function boot()
{
    Schema::defaultStringLength(191);
}

Then, change the charset and collation values as follows, in config\database.php:

'charset' => 'utf8',
'collation' => 'utf8_unicode_ci',

(link to know about MariaDB charset)

XPath Query: get attribute href from a tag

The answer shared by @mockinterface is correct. Although I would like to add my 2 cents to it.

If someone is using frameworks like scrapy the you will have to use /html/body//a[contains(@href,'com')][2]/@href along with get() like this:

response.xpath('//a[contains(@href,'com')][2]/@href').get()

SQLSTATE[42S22]: Column not found: 1054 Unknown column - Laravel

Try to change where Member class

public function users() {
    return $this->hasOne('User');
} 

return $this->belongsTo('User');

ImportError: cannot import name

The problem is that you have a circular import: in app.py

from mod_login import mod_login

in mod_login.py

from app import app

This is not permitted in Python. See Circular import dependency in Python for more info. In short, the solution are

  • either gather everything in one big file
  • delay one of the import using local import

What is the definition of "interface" in object oriented programming

In short, The basic problem an interface is trying to solve is to separate how we use something from how it is implemented. But you should consider interface is not a contract. Read more here.

How to use Git?

git clone your-url local-dir

to checkout source code;

git pull

to update source code in local-dir;

Spool Command: Do not output SQL statement to file

set echo off
spool c:\test.csv 
select /*csv*/ username, user_id, created from all_users;
spool off;

How should I import data from CSV into a Postgres table using pgAdmin 3?

You may have a table called 'test'

COPY test(gid, "name", the_geom)
FROM '/home/data/sample.csv'
WITH DELIMITER ','
CSV HEADER

How can you make a custom keyboard in Android?

Well Suragch gave the best answer so far but he skipped certain minor stuff that was important to getting the app compiled.

I hope to make a better answer than Suragch by improving on his answer. I will add all the missing elements he didnt put.

I compiled my apk using the android app , APK Builder 1.1.0. So let's begin.

To build an Android app we need couple files and folders that are organized in a certain format and capitalized accordingly.

res layout -> xml files depicting how app will look on phone. Similar to how html shapes how web page looks on browser. Allowing your app to fit on screens accordingly.

values -> constant data such as colors.xml, strings.xml, styles.xml. These files must be properly spelt.

drawable -> pics{jpeg, png,...}; Name them anything.

mipmap -> more pics. used for app icon?

xml -> more xml files.

src -> acts like JavaScript in html. layout files will initiate the starting view and your java file will dynamically control the tag elements and trigger events. Events can also be activated directly in the layout.xml just like in html.

AndroidManifest.xml -> This file registers what your app is about. Application name, Type of program, permissions needed, etc. This seems to make Android rather safe. Programs literally cannot do what they didnt ask for in the Manifest.

Now there are 4 types of Android programs, an activity, a service, a content provider, and a broadcast reciever. Our keyboard will be a service, which allows it to run in the background. It will not appear in the list of apps to launch; but it can be uninstalled.

To compile your app, involves gradle, and apk signing. You can research that one or use APK Builder for android. It is super easy.

Now that we understand Android development, let us create the files and folders.

  1. Create the files and folders as I discussed above. My directory wil look as follows:

    • NumPad
      • AndroidManifest.xml
      • src
        • Saragch
          • num_pad
            • MyInputMethodService.java
      • res
        • drawable
          • Suragch_NumPad_icon.png
        • layout
          • key_preview.xml
          • keyboard_view.xml
        • xml
          • method.xml
          • number_pad.xml
        • values
          • colors.xml
          • strings.xml
          • styles.xml

Remember if you are using an ide such as Android Studio it may have a project file.

  1. Write files.

A: NumPad/res/layout/key_preview.xml

<?xml version="1.0" encoding="utf-8"?>
   <TextView
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:gravity="center"
      android:background="@android:color/white"
      android:textColor="@android:color/black"
      android:textSize="30sp">
</TextView>

B: NumPad/res/layout/keyboard_view.xml

<?xml version="1.0" encoding="utf-8"?>
<android.inputmethodservice.KeyboardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/keyboard_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:keyPreviewLayout="@layout/key_preview"
    android:layout_alignParentBottom="true">

</android.inputmethodservice.KeyboardView>

C: NumPad/res/xml/method.xml

<?xml version="1.0" encoding="utf-8"?>
<input-method  xmlns:android="http://schemas.android.com/apk/res/android">
    <subtype  android:imeSubtypeMode="keyboard"/>
</input-method>

D: Numpad/res/xml/number_pad.xml

<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
    android:keyWidth="20%p"
    android:horizontalGap="5dp"
    android:verticalGap="5dp"
    android:keyHeight="60dp">

    <Row>
        <Key android:codes="49" android:keyLabel="1" android:keyEdgeFlags="left"/>
        <Key android:codes="50" android:keyLabel="2"/>
        <Key android:codes="51" android:keyLabel="3"/>
        <Key android:codes="52" android:keyLabel="4"/>
        <Key android:codes="53" android:keyLabel="5" android:keyEdgeFlags="right"/>
    </Row>

    <Row>
        <Key android:codes="54" android:keyLabel="6" android:keyEdgeFlags="left"/>
        <Key android:codes="55" android:keyLabel="7"/>
        <Key android:codes="56" android:keyLabel="8"/>
        <Key android:codes="57" android:keyLabel="9"/>
        <Key android:codes="48" android:keyLabel="0" android:keyEdgeFlags="right"/>
    </Row>

    <Row>
        <Key android:codes="-5"
             android:keyLabel="DELETE"
             android:keyWidth="40%p"
             android:keyEdgeFlags="left"
             android:isRepeatable="true"/>
        <Key android:codes="10"
             android:keyLabel="ENTER"
             android:keyWidth="60%p"
             android:keyEdgeFlags="right"/>
    </Row>

</Keyboard>

Of course this can be easily edited to your liking. You can even use images instead lf words for the label.

Suragch didnt demonstrate the files in the values folder and assumed we had access to Android Studio; which automatically creates them. Good thing I have APK Builder.

E: NumPad/res/values/colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#FF4081</color>
</resources>

F: NumPad/res/values/strings.xml

<resources>
    <string name="app_name">Suragch NumPad</string>
</resources>

G: NumPad/res/values/styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="android:Theme.Material.Light.DarkActionBar">
        <!-- Customize your theme here. -->
    </style>

</resources>

H: Numpad/AndroidManifest.xml

This is the file that was really up for contension. Here I felt I would never compile my program. sob. sob. If you check Suracgh's answer you see he leaves the first set of fields empty, and adds the activity tag in this file. As I said there are four types of Android programs. An activity is a regular app with a launcher icon. This numpad is not an activity! Further he didnt implement any activity.

My friends do not include the activity tag. Your program will compile, and when you try to launch it will crash! As for xmlns:android and uses-sdk; I cant help you there. Just try my settings if they work.

As you can see there is a service tag, which register it as a service. Also service.android:name must be name of public class extending service in our java file. It MUST be capitalized accordingly. Also package is the name of the package we declared in java file.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="Saragch.num_pad">

    <uses-sdk
        android:minSdkVersion="12"
        android:targetSdkVersion="27" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/Suragch_NumPad_icon"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <service
            android:name=".MyInputMethodService"
            android:label="Keyboard Display Name"
            android:permission="android.permission.BIND_INPUT_METHOD">

            <intent-filter>
                <action android:name="android.view.InputMethod"/>
            </intent-filter>

            <meta-data
                android:name="android.view.im"
                android:resource="@xml/method"/>

        </service>

    </application>
</manifest>

I: NumPad/src/Saragch/num_pad/MyInputMethodService.java

Note: I think java is an alternative to src.

This was another problem file but not as contentious as the manifest file. As I know Java good enough to know what is what, what is not. I barely know xml and how it ties in with Android development!

The problem here was he didnt import anything! I mean, he gave us a "complete" file which uses names that couldnt be resolved! InputMethodService, Keyboard, etc. That is bad practice Mr. Suragch. Thanks for helping me out but how did you expect the code to compile if the names cant be resolved?

Following is the correctly edited version. I just happened to pounce upon couple hints to drove me to the right place to learn what exactly to import.

package Saragch.num_pad;

import android.inputmethodservice.InputMethodService;
import android.inputmethodservice.KeyboardView;
import android.inputmethodservice.Keyboard;

import android.text.TextUtils;
import android.view.inputmethod.InputConnection;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;


public class MyInputMethodService extends InputMethodService implements KeyboardView.OnKeyboardActionListener 
{
    @Override
    public View onCreateInputView() 
    {
     // get the KeyboardView and add our Keyboard layout to it
     KeyboardView keyboardView = (KeyboardView)getLayoutInflater().inflate(R.layout.keyboard_view, null);
     Keyboard keyboard = new Keyboard(this, R.xml.number_pad);
     keyboardView.setKeyboard(keyboard);
     keyboardView.setOnKeyboardActionListener(this);
     return keyboardView;
    }

    @Override
    public void onKey(int primaryCode, int[] keyCodes) 
    {

        InputConnection ic = getCurrentInputConnection();

        if (ic == null) return;

        switch (primaryCode)
        {
         case Keyboard.KEYCODE_DELETE:
            CharSequence selectedText = ic.getSelectedText(0);

            if (TextUtils.isEmpty(selectedText)) 
            {
             // no selection, so delete previous character
             ic.deleteSurroundingText(1, 0);
            }

            else 
            {
             // delete the selection
             ic.commitText("", 1);
            }

            ic.deleteSurroundingText(1, 0);
            break;

         default:
            char code = (char) primaryCode;
            ic.commitText(String.valueOf(code), 1);
        }
    }

    @Override
    public void onPress(int primaryCode) { }

    @Override
    public void onRelease(int primaryCode) { }

    @Override
    public void onText(CharSequence text) { }

    @Override
    public void swipeLeft() { }

    @Override
    public void swipeRight() { }

    @Override
    public void swipeDown() { }

    @Override
    public void swipeUp() { }
}
  1. Compile and sign your project.

    This is where I am clueless as a newby Android developer. I would like to learn it manually, as I believe real programmers can compile manually.

I think gradle is one of the tools for compiling and packaging to apk. apk seems to be like a jar file or a rar for zip file. There are then two types of signing. debug key which is not alllowed on play store and private key.

Well lets give Mr. Saragch a hand. And thank you for watching my video. Like, subscribe.

How to write to a CSV line by line?

To complement the previous answers, I whipped up a quick class to write to CSV files. It makes it easier to manage and close open files and achieve consistency and cleaner code if you have to deal with multiple files.

class CSVWriter():

    filename = None
    fp = None
    writer = None

    def __init__(self, filename):
        self.filename = filename
        self.fp = open(self.filename, 'w', encoding='utf8')
        self.writer = csv.writer(self.fp, delimiter=';', quotechar='"', quoting=csv.QUOTE_ALL, lineterminator='\n')

    def close(self):
        self.fp.close()

    def write(self, elems):
        self.writer.writerow(elems)

    def size(self):
        return os.path.getsize(self.filename)

    def fname(self):
        return self.filename

Example usage:

mycsv = CSVWriter('/tmp/test.csv')
mycsv.write((12,'green','apples'))
mycsv.write((7,'yellow','bananas'))
mycsv.close()
print("Written %d bytes to %s" % (mycsv.size(), mycsv.fname()))

Have fun

What does the restrict keyword mean in C++?

There's no such keyword in C++. List of C++ keywords can be found in section 2.11/1 of C++ language standard. restrict is a keyword in C99 version of C language and not in C++.

How to plot two histograms together in R?

Here is an example of how you can do it in "classic" R graphics:

## generate some random data
carrotLengths <- rnorm(1000,15,5)
cucumberLengths <- rnorm(200,20,7)
## calculate the histograms - don't plot yet
histCarrot <- hist(carrotLengths,plot = FALSE)
histCucumber <- hist(cucumberLengths,plot = FALSE)
## calculate the range of the graph
xlim <- range(histCucumber$breaks,histCarrot$breaks)
ylim <- range(0,histCucumber$density,
              histCarrot$density)
## plot the first graph
plot(histCarrot,xlim = xlim, ylim = ylim,
     col = rgb(1,0,0,0.4),xlab = 'Lengths',
     freq = FALSE, ## relative, not absolute frequency
     main = 'Distribution of carrots and cucumbers')
## plot the second graph on top of this
opar <- par(new = FALSE)
plot(histCucumber,xlim = xlim, ylim = ylim,
     xaxt = 'n', yaxt = 'n', ## don't add axes
     col = rgb(0,0,1,0.4), add = TRUE,
     freq = FALSE) ## relative, not absolute frequency
## add a legend in the corner
legend('topleft',c('Carrots','Cucumbers'),
       fill = rgb(1:0,0,0:1,0.4), bty = 'n',
       border = NA)
par(opar)

The only issue with this is that it looks much better if the histogram breaks are aligned, which may have to be done manually (in the arguments passed to hist).

Check if a string contains a substring in SQL Server 2005, using a stored procedure

You can just use wildcards in the predicate (after IF, WHERE or ON):

@mainstring LIKE '%' + @substring + '%'

or in this specific case

' ' + @mainstring + ' ' LIKE '% ME[., ]%'

(Put the spaces in the quoted string if you're looking for the whole word, or leave them out if ME can be part of a bigger word).

Disable/enable an input with jQuery?

2018, without JQuery (ES6)

Disable all input:

[...document.querySelectorAll('input')].map(e => e.disabled = true);

Disable input with id="my-input"

document.getElementById('my-input').disabled = true;

The question is with JQuery, it's just FYI.

Change input text border color without changing its height

This css solution worked for me:

input:active,
input:focus {
    border: 1px solid #red
}

input:active,
input:focus {
    padding: 2px solid #red /*for firefox and chrome*/
}

/* .ie is a class you would need to set at the html root level */
.ie input:active,
.ie input:focus {
    padding: 3px solid #red /* IE needs 1px extra padding*/
}

I understand it is not necessary on FF and Chrome, but IE needs it. And there are circumstances when you need it.

How to check if an element is in an array

Swift 2, 3, 4, 5:

let elements = [1, 2, 3, 4, 5]
if elements.contains(5) {
    print("yes")
}

contains() is a protocol extension method of SequenceType (for sequences of Equatable elements) and not a global method as in earlier releases.

Remarks:

Swift older versions:

let elements = [1,2,3,4,5]
if contains(elements, 5) {
    println("yes")
}

How do I detect if a user is already logged in Firebase?

If you are allowing anonymous users as well as those logged in with email you can use firebase.auth().currentUser.isAnonymous, which will return either true or false.

How to make code wait while calling asynchronous calls like Ajax

Use callbacks. Something like this should work based on your sample code.

function someFunc() {

callAjaxfunc(function() {
    console.log('Pass2');
});

}

function callAjaxfunc(callback) {
    //All ajax calls called here
    onAjaxSuccess: function() {
        callback();
    };
    console.log('Pass1');    
}

This will print Pass1 immediately (assuming ajax request takes atleast a few microseconds), then print Pass2 when the onAjaxSuccess is executed.

Using multiple delimiters in awk

I see many perfect answers are up on the board, but still would like to upload my piece of code too,

awk -F"/" '{print $3 " " $5 " " $7}' sam | sed 's/ cat.* =//g'

Location of GlassFish Server Logs

Locate the installation path of GlassFish. Then move to domains/domain-dir/logs/ and you'll find there the log files. If you have created the domain with NetBeans, the domain-dir is most probably called domain1.

See this link for the official GlassFish documentation about logging.

Gradle error: could not execute build using gradle distribution

This problem occurred to me when I edited the configurations in Android Studio to use the Desktop. However, using the default(android) seems to work well without any issues.

How do I import a .bak file into Microsoft SQL Server 2012?

You can use the following script if you don't wish to use Wizard;

RESTORE DATABASE myDB
FROM  DISK = N'C:\BackupDB.bak' 
WITH  REPLACE,RECOVERY,  
MOVE N'HRNET' TO N'C:\MSSQL\Data\myDB.mdf',  
MOVE N'HRNET_LOG' TO N'C:\MSSQL\Data\myDB.ldf'

How to generate a random alpha-numeric string

Here it is a Scala solution:

(for (i <- 0 until rnd.nextInt(64)) yield { 
  ('0' + rnd.nextInt(64)).asInstanceOf[Char] 
}) mkString("")

How to change angular port from 4200 to any other

We have two ways to change default port number in Angular.

First way to cli command:

ng serve --port 2400 --open

Second way is by configuration at the location: ProjectName\node_modules\@angular-devkit\build-angular\src\dev-server\schema.json.

Make changes in schema.json file.

{
 "title": "Dev Server Target",
  "description": "Dev Server target options for Build Facade.",
  "type": "object",
  "properties": {
    "browserTarget": {
      "type": "string",
      "description": "Target to serve."
    },
    "port": {
      "type": "number",
      "description": "Port to listen on.",
      "default": 2400
    },

Rotating a two-dimensional array in Python

Just an observation. The input is a list of lists, but the output from the very nice solution: rotated = zip(*original[::-1]) returns a list of tuples.

This may or may not be an issue.

It is, however, easily corrected:

original = [[1, 2, 3],
            [4, 5, 6],
            [7, 8, 9]
            ]


def rotated(array_2d):
    list_of_tuples = zip(*array_2d[::-1])
    return [list(elem) for elem in list_of_tuples]
    # return map(list, list_of_tuples)

print(list(rotated(original)))

# [[7, 4, 1], [8, 5, 2], [9, 6, 3]]

The list comp or the map will both convert the interior tuples back to lists.

HTML5 record audio to file

The code shown below is copyrighted to Matt Diamond and available for use under MIT license. The original files are here:

Save this files and use

_x000D_
_x000D_
(function(window){_x000D_
_x000D_
      var WORKER_PATH = 'recorderWorker.js';_x000D_
      var Recorder = function(source, cfg){_x000D_
        var config = cfg || {};_x000D_
        var bufferLen = config.bufferLen || 4096;_x000D_
        this.context = source.context;_x000D_
        this.node = this.context.createScriptProcessor(bufferLen, 2, 2);_x000D_
        var worker = new Worker(config.workerPath || WORKER_PATH);_x000D_
        worker.postMessage({_x000D_
          command: 'init',_x000D_
          config: {_x000D_
            sampleRate: this.context.sampleRate_x000D_
          }_x000D_
        });_x000D_
        var recording = false,_x000D_
          currCallback;_x000D_
_x000D_
        this.node.onaudioprocess = function(e){_x000D_
          if (!recording) return;_x000D_
          worker.postMessage({_x000D_
            command: 'record',_x000D_
            buffer: [_x000D_
              e.inputBuffer.getChannelData(0),_x000D_
              e.inputBuffer.getChannelData(1)_x000D_
            ]_x000D_
          });_x000D_
        }_x000D_
_x000D_
        this.configure = function(cfg){_x000D_
          for (var prop in cfg){_x000D_
            if (cfg.hasOwnProperty(prop)){_x000D_
              config[prop] = cfg[prop];_x000D_
            }_x000D_
          }_x000D_
        }_x000D_
_x000D_
        this.record = function(){_x000D_
       _x000D_
          recording = true;_x000D_
        }_x000D_
_x000D_
        this.stop = function(){_x000D_
        _x000D_
          recording = false;_x000D_
        }_x000D_
_x000D_
        this.clear = function(){_x000D_
          worker.postMessage({ command: 'clear' });_x000D_
        }_x000D_
_x000D_
        this.getBuffer = function(cb) {_x000D_
          currCallback = cb || config.callback;_x000D_
          worker.postMessage({ command: 'getBuffer' })_x000D_
        }_x000D_
_x000D_
        this.exportWAV = function(cb, type){_x000D_
          currCallback = cb || config.callback;_x000D_
          type = type || config.type || 'audio/wav';_x000D_
          if (!currCallback) throw new Error('Callback not set');_x000D_
          worker.postMessage({_x000D_
            command: 'exportWAV',_x000D_
            type: type_x000D_
          });_x000D_
        }_x000D_
_x000D_
        worker.onmessage = function(e){_x000D_
          var blob = e.data;_x000D_
          currCallback(blob);_x000D_
        }_x000D_
_x000D_
        source.connect(this.node);_x000D_
        this.node.connect(this.context.destination);    //this should not be necessary_x000D_
      };_x000D_
_x000D_
      Recorder.forceDownload = function(blob, filename){_x000D_
        var url = (window.URL || window.webkitURL).createObjectURL(blob);_x000D_
        var link = window.document.createElement('a');_x000D_
        link.href = url;_x000D_
        link.download = filename || 'output.wav';_x000D_
        var click = document.createEvent("Event");_x000D_
        click.initEvent("click", true, true);_x000D_
        link.dispatchEvent(click);_x000D_
      }_x000D_
_x000D_
      window.Recorder = Recorder;_x000D_
_x000D_
    })(window);_x000D_
_x000D_
    //ADDITIONAL JS recorderWorker.js_x000D_
    var recLength = 0,_x000D_
      recBuffersL = [],_x000D_
      recBuffersR = [],_x000D_
      sampleRate;_x000D_
    this.onmessage = function(e){_x000D_
      switch(e.data.command){_x000D_
        case 'init':_x000D_
          init(e.data.config);_x000D_
          break;_x000D_
        case 'record':_x000D_
          record(e.data.buffer);_x000D_
          break;_x000D_
        case 'exportWAV':_x000D_
          exportWAV(e.data.type);_x000D_
          break;_x000D_
        case 'getBuffer':_x000D_
          getBuffer();_x000D_
          break;_x000D_
        case 'clear':_x000D_
          clear();_x000D_
          break;_x000D_
      }_x000D_
    };_x000D_
_x000D_
    function init(config){_x000D_
      sampleRate = config.sampleRate;_x000D_
    }_x000D_
_x000D_
    function record(inputBuffer){_x000D_
_x000D_
      recBuffersL.push(inputBuffer[0]);_x000D_
      recBuffersR.push(inputBuffer[1]);_x000D_
      recLength += inputBuffer[0].length;_x000D_
    }_x000D_
_x000D_
    function exportWAV(type){_x000D_
      var bufferL = mergeBuffers(recBuffersL, recLength);_x000D_
      var bufferR = mergeBuffers(recBuffersR, recLength);_x000D_
      var interleaved = interleave(bufferL, bufferR);_x000D_
      var dataview = encodeWAV(interleaved);_x000D_
      var audioBlob = new Blob([dataview], { type: type });_x000D_
_x000D_
      this.postMessage(audioBlob);_x000D_
    }_x000D_
_x000D_
    function getBuffer() {_x000D_
      var buffers = [];_x000D_
      buffers.push( mergeBuffers(recBuffersL, recLength) );_x000D_
      buffers.push( mergeBuffers(recBuffersR, recLength) );_x000D_
      this.postMessage(buffers);_x000D_
    }_x000D_
_x000D_
    function clear(){_x000D_
      recLength = 0;_x000D_
      recBuffersL = [];_x000D_
      recBuffersR = [];_x000D_
    }_x000D_
_x000D_
    function mergeBuffers(recBuffers, recLength){_x000D_
      var result = new Float32Array(recLength);_x000D_
      var offset = 0;_x000D_
      for (var i = 0; i < recBuffers.length; i++){_x000D_
        result.set(recBuffers[i], offset);_x000D_
        offset += recBuffers[i].length;_x000D_
      }_x000D_
      return result;_x000D_
    }_x000D_
_x000D_
    function interleave(inputL, inputR){_x000D_
      var length = inputL.length + inputR.length;_x000D_
      var result = new Float32Array(length);_x000D_
_x000D_
      var index = 0,_x000D_
        inputIndex = 0;_x000D_
_x000D_
      while (index < length){_x000D_
        result[index++] = inputL[inputIndex];_x000D_
        result[index++] = inputR[inputIndex];_x000D_
        inputIndex++;_x000D_
      }_x000D_
      return result;_x000D_
    }_x000D_
_x000D_
    function floatTo16BitPCM(output, offset, input){_x000D_
      for (var i = 0; i < input.length; i++, offset+=2){_x000D_
        var s = Math.max(-1, Math.min(1, input[i]));_x000D_
        output.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true);_x000D_
      }_x000D_
    }_x000D_
_x000D_
    function writeString(view, offset, string){_x000D_
      for (var i = 0; i < string.length; i++){_x000D_
        view.setUint8(offset + i, string.charCodeAt(i));_x000D_
      }_x000D_
    }_x000D_
_x000D_
    function encodeWAV(samples){_x000D_
      var buffer = new ArrayBuffer(44 + samples.length * 2);_x000D_
      var view = new DataView(buffer);_x000D_
_x000D_
      /* RIFF identifier */_x000D_
      writeString(view, 0, 'RIFF');_x000D_
      /* file length */_x000D_
      view.setUint32(4, 32 + samples.length * 2, true);_x000D_
      /* RIFF type */_x000D_
      writeString(view, 8, 'WAVE');_x000D_
      /* format chunk identifier */_x000D_
      writeString(view, 12, 'fmt ');_x000D_
      /* format chunk length */_x000D_
      view.setUint32(16, 16, true);_x000D_
      /* sample format (raw) */_x000D_
      view.setUint16(20, 1, true);_x000D_
      /* channel count */_x000D_
      view.setUint16(22, 2, true);_x000D_
      /* sample rate */_x000D_
      view.setUint32(24, sampleRate, true);_x000D_
      /* byte rate (sample rate * block align) */_x000D_
      view.setUint32(28, sampleRate * 4, true);_x000D_
      /* block align (channel count * bytes per sample) */_x000D_
      view.setUint16(32, 4, true);_x000D_
      /* bits per sample */_x000D_
      view.setUint16(34, 16, true);_x000D_
      /* data chunk identifier */_x000D_
      writeString(view, 36, 'data');_x000D_
      /* data chunk length */_x000D_
      view.setUint32(40, samples.length * 2, true);_x000D_
_x000D_
      floatTo16BitPCM(view, 44, samples);_x000D_
_x000D_
      return view;_x000D_
    }
_x000D_
<html>_x000D_
     <body>_x000D_
      <audio controls autoplay></audio>_x000D_
      <script type="text/javascript" src="recorder.js"> </script>_x000D_
                    <fieldset><legend>RECORD AUDIO</legend>_x000D_
      <input onclick="startRecording()" type="button" value="start recording" />_x000D_
      <input onclick="stopRecording()" type="button" value="stop recording and play" />_x000D_
                    </fieldset>_x000D_
      <script>_x000D_
       var onFail = function(e) {_x000D_
        console.log('Rejected!', e);_x000D_
       };_x000D_
_x000D_
       var onSuccess = function(s) {_x000D_
        var context = new webkitAudioContext();_x000D_
        var mediaStreamSource = context.createMediaStreamSource(s);_x000D_
        recorder = new Recorder(mediaStreamSource);_x000D_
        recorder.record();_x000D_
_x000D_
        // audio loopback_x000D_
        // mediaStreamSource.connect(context.destination);_x000D_
       }_x000D_
_x000D_
       window.URL = window.URL || window.webkitURL;_x000D_
       navigator.getUserMedia  = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;_x000D_
_x000D_
       var recorder;_x000D_
       var audio = document.querySelector('audio');_x000D_
_x000D_
       function startRecording() {_x000D_
        if (navigator.getUserMedia) {_x000D_
         navigator.getUserMedia({audio: true}, onSuccess, onFail);_x000D_
        } else {_x000D_
         console.log('navigator.getUserMedia not present');_x000D_
        }_x000D_
       }_x000D_
_x000D_
       function stopRecording() {_x000D_
        recorder.stop();_x000D_
        recorder.exportWAV(function(s) {_x000D_
                                _x000D_
                                  audio.src = window.URL.createObjectURL(s);_x000D_
        });_x000D_
       }_x000D_
      </script>_x000D_
     </body>_x000D_
    </html>
_x000D_
_x000D_
_x000D_

Image is not showing in browser?

do not place *jsp or *html in root folder of webapp and images you want to display in same root folder browser cannot acess the image in WEB-INF folder

Java equivalent to JavaScript's encodeURIComponent that produces identical output?

I use java.net.URI#getRawPath(), e.g.

String s = "a+b c.html";
String fixed = new URI(null, null, s, null).getRawPath();

The value of fixed will be a+b%20c.html, which is what you want.

Post-processing the output of URLEncoder.encode() will obliterate any pluses that are supposed to be in the URI. For example

URLEncoder.encode("a+b c.html").replaceAll("\\+", "%20");

will give you a%20b%20c.html, which will be interpreted as a b c.html.

Turn a single number into single digits Python

The easiest way is to turn the int into a string and take each character of the string as an element of your list:

>>> n = 43365644 
>>> digits = [int(x) for x in str(n)]
>>> digits
[4, 3, 3, 6, 5, 6, 4, 4]
>>> lst.extend(digits)  # use the extends method if you want to add the list to another

It involves a casting operation, but it's readable and acceptable if you don't need extreme performance.

Count lines in large files

Try: sed -n '$=' filename

Also cat is unnecessary: wc -l filename is enough in your present way.

Calculate text width with JavaScript

The code-snips below, "calculate" the width of the span-tag, appends "..." to it if its too long and reduces the text-length, until it fits in its parent (or until it has tried more than a thousand times)

CSS

div.places {
  width : 100px;
}
div.places span {
  white-space:nowrap;
  overflow:hidden;
}

HTML

<div class="places">
  <span>This is my house</span>
</div>
<div class="places">
  <span>And my house are your house</span>
</div>
<div class="places">
  <span>This placename is most certainly too wide to fit</span>
</div>

JavaScript (with jQuery)

// loops elements classed "places" and checks if their child "span" is too long to fit
$(".places").each(function (index, item) {
    var obj = $(item).find("span");
    if (obj.length) {
        var placename = $(obj).text();
        if ($(obj).width() > $(item).width() && placename.trim().length > 0) {
            var limit = 0;
            do {
                limit++;
                                    placename = placename.substring(0, placename.length - 1);
                                    $(obj).text(placename + "...");
            } while ($(obj).width() > $(item).width() && limit < 1000)
        }
    }
});

How can I sort a List alphabetically?

Here is what you are looking for

listOfCountryNames.sort(String::compareToIgnoreCase)

How to merge remote changes at GitHub?

You can force it to push, but please do this ONLY when you're quite sure what you are doing.

The command is:

git push -f 

What Process is using all of my disk IO

Have you considered lsof (list open files)?

How abstraction and encapsulation differ?

One example has always been brought up to me in the context of abstraction; the automatic vs. manual transmission on cars. The manual transmission hides some of the workings of changing gears, but you still have to clutch and shift as a driver. Automatic transmission encapsulates all the details of changing gears, i.e. hides it from you, and it is therefore a higher abstraction of the process of changing gears.

How to set time zone of a java.util.Date?

tl;dr

…parsed … from a String … time zone is not specified … I want to set a specific time zone

LocalDateTime.parse( "2018-01-23T01:23:45.123456789" )  // Parse string, lacking an offset-from-UTC and lacking a time zone, as a `LocalDateTime`.
    .atZone( ZoneId.of( "Africa/Tunis" ) )              // Assign the time zone for which you are certain this date-time was intended. Instantiates a `ZonedDateTime` object.

No Time Zone in j.u.Date

As the other correct answers stated, a java.util.Date has no time zone. It represents UTC/GMT (no time zone offset). Very confusing because its toString method applies the JVM's default time zone when generating a String representation.

Avoid j.u.Date

For this and many other reasons, you should avoid using the built-in java.util.Date & .Calendar & java.text.SimpleDateFormat. They are notoriously troublesome.

Instead use the java.time package bundled with Java 8.

java.time

The java.time classes can represent a moment on the timeline in three ways:

  • UTC (Instant)
  • With an offset (OffsetDateTime with ZoneOffset)
  • With a time zone (ZonedDateTime with ZoneId)

Instant

In java.time, the basic building block is Instant, a moment on the time line in UTC. Use Instant objects for much of your business logic.

Instant instant = Instant.now();

OffsetDateTime

Apply an offset-from-UTC to adjust into some locality’s wall-clock time.

Apply a ZoneOffset to get an OffsetDateTime.

ZoneOffset zoneOffset = ZoneOffset.of( "-04:00" );
OffsetDateTime odt = OffsetDateTime.ofInstant( instant , zoneOffset );

ZonedDateTime

Better is to apply a time zone, an offset plus the rules for handling anomalies such as Daylight Saving Time (DST).

Apply a ZoneId to an Instant to get a ZonedDateTime. Always specify a proper time zone name. Never use 3-4 abbreviations such as EST or IST that are neither unique nor standardized.

ZoneId zoneId = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.ofInstant( instant , zoneId );

LocalDateTime

If the input string lacked any indicator of offset or zone, parse as a LocalDateTime.

If you are certain of the intended time zone, assign a ZoneId to produce a ZonedDateTime. See code example above in tl;dr section at top.

Formatted Strings

Call the toString method on any of these three classes to generate a String representing the date-time value in standard ISO 8601 format. The ZonedDateTime class extends standard format by appending the name of the time zone in brackets.

String outputInstant = instant.toString(); // Ex: 2011-12-03T10:15:30Z
String outputOdt = odt.toString(); // Ex: 2007-12-03T10:15:30+01:00
String outputZdt = zdt.toString(); // Ex: 2007-12-03T10:15:30+01:00[Europe/Paris]

For other formats use the DateTimeFormatter class. Generally best to let that class generate localized formats using the user’s expected human language and cultural norms. Or you can specify a particular format.


Table of all date-time types in Java, both modern and legacy


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.

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

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

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. Hibernate 5 & JPA 2.2 support java.time.

Where to obtain the java.time classes?


Joda-Time

While Joda-Time is still actively maintained, its makers have told us to migrate to java.time as soon as is convenient. I leave this section intact as a reference, but I suggest using the java.time section above instead.

In Joda-Time, a date-time object (DateTime) truly does know its assigned time zone. That means an offset from UTC and the rules and history of that time zone’s Daylight Saving Time (DST) and other such anomalies.

String input = "2014-01-02T03:04:05";
DateTimeZone timeZone = DateTimeZone.forID( "Asia/Kolkata" );
DateTime dateTimeIndia = new DateTime( input, timeZone );
DateTime dateTimeUtcGmt = dateTimeIndia.withZone( DateTimeZone.UTC );

Call the toString method to generate a String in ISO 8601 format.

String output = dateTimeIndia.toString();

Joda-Time also offers rich capabilities for generating all kinds of other String formats.

If required, you can convert from Joda-Time DateTime to a java.util.Date.

Java.util.Date date = dateTimeIndia.toDate();

Search StackOverflow for "joda date" to find many more examples, some quite detailed.


Actually there is a time zone embedded in a java.util.Date, used for some internal functions (see comments on this Answer). But this internal time zone is not exposed as a property, and cannot be set. This internal time zone is not the one used by the toString method in generating a string representation of the date-time value; instead the JVM’s current default time zone is applied on-the-fly. So, as shorthand, we often say “j.u.Date has no time zone”. Confusing? Yes. Yet another reason to avoid these tired old classes.

GROUP BY to combine/concat a column

A good question. Should tell you it took some time to crack this one. Here is my result.

DECLARE @TABLE TABLE
(  
ID INT,  
USERS VARCHAR(10),  
ACTIVITY VARCHAR(10),  
PAGEURL VARCHAR(10)  
)

INSERT INTO @TABLE  
VALUES  (1, 'Me', 'act1', 'ab'),
        (2, 'Me', 'act1', 'cd'),
        (3, 'You', 'act2', 'xy'),
        (4, 'You', 'act2', 'st')


SELECT T1.USERS, T1.ACTIVITY,   
        STUFF(  
        (  
        SELECT ',' + T2.PAGEURL  
        FROM @TABLE T2  
        WHERE T1.USERS = T2.USERS  
        FOR XML PATH ('')  
        ),1,1,'')  
FROM @TABLE T1  
GROUP BY T1.USERS, T1.ACTIVITY

Android:java.lang.OutOfMemoryError: Failed to allocate a 23970828 byte allocation with 2097152 free bytes and 2MB until OOM

I suppose you want to use this image as an icon. As Android is telling you, your image is too large. What you just need to do is scale your image so that Android knows which size of the image to use and when according to screen resolution. To accomplish this, in Android Studio: 1. right click on the res folder, 2. select Image Asset 3. Select icon Type 4. Give the icon a name 5. Select Image on Asset Type 6. Trim your image Click next and finish. In your xml or source code just refer to the image which will now be located either in the layout or mipmap folder according to asset type selected. The error will go away.

How to update gradle in android studio?

On Mac, open terminal and run the following commands as per instructions:

$ curl -s https://get.sdkman.io | bash

then

$ sdk install gradle 3.0

Once the installation is complete, the terminal would ask whether to set it as a default version so type y and make it the default version.

Now open Android Studio -> Terminal and run the following command

Gradle --version

Best way to store date/time in mongodb

One datestamp is already in the _id object, representing insert time

So if the insert time is what you need, it's already there:

Login to mongodb shell

ubuntu@ip-10-0-1-223:~$ mongo 10.0.1.223
MongoDB shell version: 2.4.9
connecting to: 10.0.1.223/test

Create your database by inserting items

> db.penguins.insert({"penguin": "skipper"})
> db.penguins.insert({"penguin": "kowalski"})
> 

Lets make that database the one we are on now

> use penguins
switched to db penguins

Get the rows back:

> db.penguins.find()
{ "_id" : ObjectId("5498da1bf83a61f58ef6c6d5"), "penguin" : "skipper" }
{ "_id" : ObjectId("5498da28f83a61f58ef6c6d6"), "penguin" : "kowalski" }

Get each row in yyyy-MM-dd HH:mm:ss format:

> db.penguins.find().forEach(function (doc){ d = doc._id.getTimestamp(); print(d.getFullYear()+"-"+(d.getMonth()+1)+"-"+d.getDate() + " " + d.getHours() + ":" + d.getMinutes() + ":" + d.getSeconds()) })
2014-12-23 3:4:41
2014-12-23 3:4:53

If that last one-liner confuses you I have a walkthrough on how that works here: https://stackoverflow.com/a/27613766/445131

Converting String to "Character" array in Java

If you don't want to rely on third party API's, here is a working code for JDK7 or below. I am not instantiating temporary Character Objects as done by other solutions above. foreach loops are more readable, see yourself :)

public static Character[] convertStringToCharacterArray(String str) {
    if (str == null || str.isEmpty()) {
        return null;
    }
    char[] c = str.toCharArray();
    final int len = c.length;
    int counter = 0;
    final Character[] result = new Character[len];
    while (len > counter) {
        for (char ch : c) {
            result[counter++] = ch;
        }
    }
    return result;
}

CSS: On hover show and hide different div's at the same time?

if the other div is sibling/child, or any combination of, of the parent yes

_x000D_
_x000D_
    .showme{ _x000D_
        display: none;_x000D_
    }_x000D_
    .showhim:hover .showme{_x000D_
        display : block;_x000D_
    }_x000D_
    .showhim:hover .hideme{_x000D_
        display : none;_x000D_
    }_x000D_
    .showhim:hover ~ .hideme2{ _x000D_
        display:none;_x000D_
    }
_x000D_
    <div class="showhim">_x000D_
        HOVER ME_x000D_
        <div class="showme">hai</div> _x000D_
        <div class="hideme">bye</div>_x000D_
    </div>_x000D_
    <div class="hideme2">bye bye</div>
_x000D_
_x000D_
_x000D_

Delete first character of a string in Javascript

Very readable code is to use .substring() with a start set to index of the second character (1) (first character has index 0). Second parameter of the .substring() method is actually optional, so you don't even need to call .length()...

TL;DR : Remove first character from the string:

str = str.substring(1);

...yes it is that simple...

Removing some particular character(s):

As @Shaded suggested, just loop this while first character of your string is the "unwanted" character...

var yourString = "0000test";
var unwantedCharacter = "0";
//there is really no need for === check, since we use String's charAt()
while( yourString.charAt(0) == unwantedCharacter ) yourString = yourString.substring(1);
//yourString now contains "test"

.slice() vs .substring() vs .substr()

EDIT: substr() is not standardized and should not be used for new JS codes, you may be inclined to use it because of the naming similarity with other languages, e.g. PHP, but even in PHP you should probably use mb_substr() to be safe in modern world :)

Quote from (and more on that in) What is the difference between String.slice and String.substring?

He also points out that if the parameters to slice are negative, they reference the string from the end. Substring and substr doesn´t.

Eclipse CDT: Symbol 'cout' could not be resolved

Just adding yet another bit of advice after trying a bunch of stuff myself and it not working....

I had GCC installed and the path to the includes set correctly. Had the std error as well, and couldn't get anything working for cout (and I suspect anything in the SL...)

Took me awhile to realize that g++ wasn't installed - gcc was but not g++. So just do:

sudo apt-get install g++

Restart eclipse. Assuming above mentioned details about gcc & paths to includes are fine, you should be okay now...

React.js: Wrapping one component into another

Using children

const Wrapper = ({children}) => (
  <div>
    <div>header</div>
    <div>{children}</div>
    <div>footer</div>
  </div>
);

const App = ({name}) => <div>Hello {name}</div>;

const WrappedApp = ({name}) => (
  <Wrapper>
    <App name={name}/>
  </Wrapper>
);

render(<WrappedApp name="toto"/>,node);

This is also known as transclusion in Angular.

children is a special prop in React and will contain what is inside your component's tags (here <App name={name}/> is inside Wrapper, so it is the children

Note that you don't necessarily need to use children, which is unique for a component, and you can use normal props too if you want, or mix props and children:

const AppLayout = ({header,footer,children}) => (
  <div className="app">
    <div className="header">{header}</div>
    <div className="body">{children}</div>
    <div className="footer">{footer}</div>
  </div>
);

const appElement = (
  <AppLayout 
    header={<div>header</div>}
    footer={<div>footer</div>}
  >
    <div>body</div>
  </AppLayout>
);

render(appElement,node);

This is simple and fine for many usecases, and I'd recommend this for most consumer apps.


render props

It is possible to pass render functions to a component, this pattern is generally called render prop, and the children prop is often used to provide that callback.

This pattern is not really meant for layout. The wrapper component is generally used to hold and manage some state and inject it in its render functions.

Counter example:

const Counter = () => (
  <State initial={0}>
    {(val, set) => (
      <div onClick={() => set(val + 1)}>  
        clicked {val} times
      </div>
    )}
  </State>
); 

You can get even more fancy and even provide an object

<Promise promise={somePromise}>
  {{
    loading: () => <div>...</div>,
    success: (data) => <div>{data.something}</div>,
    error: (e) => <div>{e.message}</div>,
  }}
</Promise>

Note you don't necessarily need to use children, it is a matter of taste/API.

<Promise 
  promise={somePromise}
  renderLoading={() => <div>...</div>}
  renderSuccess={(data) => <div>{data.something}</div>}
  renderError={(e) => <div>{e.message}</div>}
/>

As of today, many libraries are using render props (React context, React-motion, Apollo...) because people tend to find this API more easy than HOC's. react-powerplug is a collection of simple render-prop components. react-adopt helps you do composition.


Higher-Order Components (HOC).

const wrapHOC = (WrappedComponent) => {
  class Wrapper extends React.PureComponent {
    render() {
      return (
        <div>
          <div>header</div>
          <div><WrappedComponent {...this.props}/></div>
          <div>footer</div>
        </div>
      );
    }  
  }
  return Wrapper;
}

const App = ({name}) => <div>Hello {name}</div>;

const WrappedApp = wrapHOC(App);

render(<WrappedApp name="toto"/>,node);

An Higher-Order Component / HOC is generally a function that takes a component and returns a new component.

Using an Higher-Order Component can be more performant than using children or render props, because the wrapper can have the ability to short-circuit the rendering one step ahead with shouldComponentUpdate.

Here we are using PureComponent. When re-rendering the app, if the WrappedApp name prop does not change over time, the wrapper has the ability to say "I don't need to render because props (actually, the name) are the same as before". With the children based solution above, even if the wrapper is PureComponent, it is not the case because the children element is recreated everytime the parent renders, which means the wrapper will likely always re-render, even if the wrapped component is pure. There is a babel plugin that can help mitigate this and ensure a constant children element over time.


Conclusion

Higher-Order Components can give you better performance. It's not so complicated but it certainly looks unfriendly at first.

Don't migrate your whole codebase to HOC after reading this. Just remember that on critical paths of your app you might want to use HOCs instead of runtime wrappers for performance reasons, particularly if the same wrapper is used a lot of times it's worth considering making it an HOC.

Redux used at first a runtime wrapper <Connect> and switched later to an HOC connect(options)(Comp) for performance reasons (by default, the wrapper is pure and use shouldComponentUpdate). This is the perfect illustration of what I wanted to highlight in this answer.

Note if a component has a render-prop API, it is generally easy to create a HOC on top of it, so if you are a lib author, you should write a render prop API first, and eventually offer an HOC version. This is what Apollo does with <Query> render-prop component, and the graphql HOC using it.

Personally, I use both, but when in doubt I prefer HOCs because:

  • It's more idiomatic to compose them (compose(hoc1,hoc2)(Comp)) compared to render props
  • It can give me better performances
  • I'm familiar with this style of programming

I don't hesitate to use/create HOC versions of my favorite tools:

  • React's Context.Consumer comp
  • Unstated's Subscribe
  • using graphql HOC of Apollo instead of Query render prop

In my opinion, sometimes render props make the code more readable, sometimes less... I try to use the most pragmatic solution according to the constraints I have. Sometimes readability is more important than performances, sometimes not. Choose wisely and don't bindly follow the 2018 trend of converting everything to render-props.

'xmlParseEntityRef: no name' warnings while loading xml into a php file

Try to clean the HTML first using this function:

$html = htmlspecialchars($html);

Special chars are usually represented differently in HTML and it might be confusing for the compiler. Like & becomes &amp;.

Setting Column width in Apache POI

Unfortunately there is only the function setColumnWidth(int columnIndex, int width) from class Sheet; in which width is a number of characters in the standard font (first font in the workbook) if your fonts are changing you cannot use it. There is explained how to calculate the width in function of a font size. The formula is:

width = Truncate([{NumOfVisibleChar} * {MaxDigitWidth} + {5PixelPadding}] / {MaxDigitWidth}*256) / 256

You can always use autoSizeColumn(int column, boolean useMergedCells) after inputting the data in your Sheet.

Entity Framework Migrations renaming tables and columns

To expand a bit on Hossein Narimani Rad's answer, you can rename both a table and columns using System.ComponentModel.DataAnnotations.Schema.TableAttribute and System.ComponentModel.DataAnnotations.Schema.ColumnAttribute respectively.

This has a couple benefits:

  1. Not only will this create the the name migrations automatically, but
  2. it will also deliciously delete any foreign keys and recreate them against the new table and column names, giving the foreign keys and constaints proper names.
  3. All this without losing any table data

For example, adding [Table("Staffs")]:

[Table("Staffs")]
public class AccountUser
{
    public long Id { get; set; }

    public long AccountId { get; set; }

    public string ApplicationUserId { get; set; }

    public virtual Account Account { get; set; }

    public virtual ApplicationUser User { get; set; }
}

Will generate the migration:

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_AccountUsers_Accounts_AccountId",
            table: "AccountUsers");

        migrationBuilder.DropForeignKey(
            name: "FK_AccountUsers_AspNetUsers_ApplicationUserId",
            table: "AccountUsers");

        migrationBuilder.DropPrimaryKey(
            name: "PK_AccountUsers",
            table: "AccountUsers");

        migrationBuilder.RenameTable(
            name: "AccountUsers",
            newName: "Staffs");

        migrationBuilder.RenameIndex(
            name: "IX_AccountUsers_ApplicationUserId",
            table: "Staffs",
            newName: "IX_Staffs_ApplicationUserId");

        migrationBuilder.RenameIndex(
            name: "IX_AccountUsers_AccountId",
            table: "Staffs",
            newName: "IX_Staffs_AccountId");

        migrationBuilder.AddPrimaryKey(
            name: "PK_Staffs",
            table: "Staffs",
            column: "Id");

        migrationBuilder.AddForeignKey(
            name: "FK_Staffs_Accounts_AccountId",
            table: "Staffs",
            column: "AccountId",
            principalTable: "Accounts",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);

        migrationBuilder.AddForeignKey(
            name: "FK_Staffs_AspNetUsers_ApplicationUserId",
            table: "Staffs",
            column: "ApplicationUserId",
            principalTable: "AspNetUsers",
            principalColumn: "Id",
            onDelete: ReferentialAction.Restrict);
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_Staffs_Accounts_AccountId",
            table: "Staffs");

        migrationBuilder.DropForeignKey(
            name: "FK_Staffs_AspNetUsers_ApplicationUserId",
            table: "Staffs");

        migrationBuilder.DropPrimaryKey(
            name: "PK_Staffs",
            table: "Staffs");

        migrationBuilder.RenameTable(
            name: "Staffs",
            newName: "AccountUsers");

        migrationBuilder.RenameIndex(
            name: "IX_Staffs_ApplicationUserId",
            table: "AccountUsers",
            newName: "IX_AccountUsers_ApplicationUserId");

        migrationBuilder.RenameIndex(
            name: "IX_Staffs_AccountId",
            table: "AccountUsers",
            newName: "IX_AccountUsers_AccountId");

        migrationBuilder.AddPrimaryKey(
            name: "PK_AccountUsers",
            table: "AccountUsers",
            column: "Id");

        migrationBuilder.AddForeignKey(
            name: "FK_AccountUsers_Accounts_AccountId",
            table: "AccountUsers",
            column: "AccountId",
            principalTable: "Accounts",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);

        migrationBuilder.AddForeignKey(
            name: "FK_AccountUsers_AspNetUsers_ApplicationUserId",
            table: "AccountUsers",
            column: "ApplicationUserId",
            principalTable: "AspNetUsers",
            principalColumn: "Id",
            onDelete: ReferentialAction.Restrict);
    }

HTML5 Canvas background image

Make sure that in case your image is not in the dom, and you get it from local directory or server, you should wait for the image to load and just after that to draw it on the canvas.

something like that:

function drawBgImg() {
    let bgImg = new Image();
    bgImg.src = '/images/1.jpg';
    bgImg.onload = () => {
        gCtx.drawImage(bgImg, 0, 0, gElCanvas.width, gElCanvas.height);
    }
}

ansible: lineinfile for several lines?

I was able to do that by using \n in the line parameter.

It is specially useful if the file can be validated, and adding a single line generates an invalid file.

In my case, I was adding AuthorizedKeysCommand and AuthorizedKeysCommandUser to sshd_config, with the following command:

- lineinfile: dest=/etc/ssh/sshd_config line='AuthorizedKeysCommand /etc/ssh/ldap-keys\nAuthorizedKeysCommandUser nobody' validate='/usr/sbin/sshd -T -f %s'

Adding only one of the options generates a file that fails validation.

Phone: numeric keyboard for text input

Using the type="email" or type="url" will give you a keyboard on some phones at least, such as iPhone. For phone numbers, you can use type="tel".

best practice font size for mobile

The whole thing to em is, that the size is relative to the base. So I would say you could keep the font sizes by altering the base.

Example: If you base is 16px, and p is .75em (which is 12px) you would have to raise the base to about 20px. In this case p would then equal about 15px which is the minimum I personally require for mobile phones.

Can you require two form fields to match with HTML5?

You can with regular expressions Input Patterns (check browser compatibility)

<input id="password" name="password" type="password" pattern="^\S{6,}$" onchange="this.setCustomValidity(this.validity.patternMismatch ? 'Must have at least 6 characters' : ''); if(this.checkValidity()) form.password_two.pattern = this.value;" placeholder="Password" required>

<input id="password_two" name="password_two" type="password" pattern="^\S{6,}$" onchange="this.setCustomValidity(this.validity.patternMismatch ? 'Please enter the same Password as above' : '');" placeholder="Verify Password" required>

Unable to load script.Make sure you are either running a Metro server or that your bundle 'index.android.bundle' is packaged correctly for release

In Some Cases You Might Want To Close the port Of React-native bundler and Rerun the App With the same process

1.sudo kill -9 $(sudo lsof -t -i:9001)

2.npm start inside the project

3. react-native run-android

How do I set the classpath in NetBeans?

  1. Right-click your Project.
  2. Select Properties.
  3. On the left-hand side click Libraries.
  4. Under Compile tab - click Add Jar/Folder button.

Or

  1. Expand your Project.
  2. Right-click Libraries.
  3. Select Add Jar/Folder.

How do I count occurrence of duplicate items in array

$search_string = 4;
$original_array = [1,2,1,3,2,4,4,4,4,4,10];
$step1 = implode(",", $original_array); // convert original_array to string
$step2 = explode($search_string, $step1); // break step1 string into a new array using the search string as delimiter
$result = count($step2)-1; // count the number of elements in the resulting array, minus the first empty element
print_r($result); // result is 5

PHP foreach with Nested Array?

Both syntaxes are correct. But the result would be Array. You probably want to do something like this:

foreach ($tmpArray[1] as $value) {
  echo $value[0];
  foreach($value[1] as $val){
    echo $val;
  }
}

This will print out the string "two" ($value[0]) and the integers 4, 5 and 6 from the array ($value[1]).

What is the "-->" operator in C/C++?

Or for something completely different... x slides to 0.

while (x --\
            \
             \
              \
               > 0)
     printf("%d ", x);

Not so mathematical, but... every picture paints a thousand words...

async for loop in node.js

You've correctly diagnosed your problem, so good job. Once you call into your search code, the for loop just keeps right on going.

I'm a big fan of https://github.com/caolan/async, and it serves me well. Basically with it you'd end up with something like:

var async = require('async')
async.eachSeries(Object.keys(config), function (key, next){ 
  search(config[key].query, function(err, result) { // <----- I added an err here
    if (err) return next(err)  // <---- don't keep going if there was an error

    var json = JSON.stringify({
      "result": result
    });
    results[key] = {
      "result": result
    }
    next()    /* <---- critical piece.  This is how the forEach knows to continue to
                       the next loop.  Must be called inside search's callback so that
                       it doesn't loop prematurely.*/
  })
}, function(err) {
  console.log('iterating done');
}); 

I hope that helps!

No module named _sqlite3

Download sqlite3:

wget http://www.sqlite.org/2016/sqlite-autoconf-3150000.tar.gz

Follow these steps to install:

$tar xvfz sqlite-autoconf-3071502.tar.gz
$cd sqlite-autoconf-3071502
$./configure --prefix=/usr/local
$make install

stop service in android

onDestroyed()

is wrong name for

onDestroy()  

Did you make a mistake only in this question or in your code too?

How can I force a long string without any blank to be wrapped?

Use a CSS method to force wrap a string that has no white-spaces. Three methods:

1) Use the CSS white-space property. To cover browser inconsistencies, you have to declare it several ways. So just put your looooong string into some block level element (e.g., div, pre, p) and give that element the following css:

some_block_level_tag {
    white-space: pre;           /* CSS 2.0 */
    white-space: pre-wrap;      /* CSS 2.1 */
    white-space: pre-line;      /* CSS 3.0 */
    white-space: -pre-wrap;     /* Opera 4-6 */
    white-space: -o-pre-wrap;   /* Opera 7 */
    white-space: -moz-pre-wrap; /* Mozilla */
    white-space: -hp-pre-wrap;  /* HP Printers */
    word-wrap: break-word;      /* IE 5+ */
}

2) use the force-wrap mixin from Compass.

3) I was just looking into this as well and I think might also work (but I need to test browser support more completely):

.break-me {
    word-wrap: break-word;
    overflow-wrap: break-word;
}

Reference: wrapping content

How to prevent form from submitting multiple times from client side?

This works very fine for me. It submit the farm and make button disable and after 2 sec active the button.

<button id="submit" type="submit" onclick="submitLimit()">Yes</button>

function submitLimit() {
var btn = document.getElementById('submit')
setTimeout(function() {
    btn.setAttribute('disabled', 'disabled');
}, 1);

setTimeout(function() {
    btn.removeAttribute('disabled');
}, 2000);}

In ECMA6 Syntex

function submitLimit() {
submitBtn = document.getElementById('submit');

setTimeout(() => { submitBtn.setAttribute('disabled', 'disabled') }, 1);

setTimeout(() => { submitBtn.removeAttribute('disabled') }, 4000);}

DataAdapter.Fill(Dataset)

DataSet ds = new DataSet();

using (OleDbConnection connection = new OleDbConnection(connectionString))
using (OleDbCommand command = new OleDbCommand(query, connection))
using (OleDbDataAdapter adapter = new OleDbDataAdapter(command))
{
    adapter.Fill(ds);
}

return ds;

Initializing C dynamic arrays

You need to allocate a block of memory and use it as an array as:

int *arr = malloc (sizeof (int) * n); /* n is the length of the array */
int i;

for (i=0; i<n; i++)
{
  arr[i] = 0;
}

If you need to initialize the array with zeros you can also use the memset function from C standard library (declared in string.h).

memset (arr, 0, sizeof (int) * n);

Here 0 is the constant with which every locatoin of the array will be set. Note that the last argument is the number of bytes to be set the the constant. Because each location of the array stores an integer therefore we need to pass the total number of bytes as this parameter.

Also if you want to clear the array to zeros, then you may want to use calloc instead of malloc. calloc will return the memory block after setting the allocated byte locations to zero.

After you have finished, free the memory block free (arr).

EDIT1

Note that if you want to assign a particular integer in locations of an integer array using memset then it will be a problem. This is because memset will interpret the array as a byte array and assign the byte you have given, to every byte of the array. So if you want to store say 11243 in each location then it will not be possible.

EDIT2

Also note why every time setting an int array to 0 with memset may not work: Why does "memset(arr, -1, sizeof(arr)/sizeof(int))" not clear an integer array to -1? as pointed out by @Shafik Yaghmour

How do I prevent an Android device from going to sleep programmatically?

Set flags on Activity's Window as below

@Override public void onResume() {
 super.onResume();
 getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}

@Override public void onPause() {
 super.onPause();
 getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}

"cannot be used as a function error"

You can't pass a function as a parameter. Simply remove it from estimatedPopulation() and replace it with 'float growthRate'. use this in your calculation instead of calling the function:

int estimatedPopulation (int currentPopulation, float growthRate)
{
    return (currentPopulation + currentPopulation * growthRate / 100);
}

and call it as:

int foo = estimatedPopulation (currentPopulation, growthRate (birthRate, deathRate));

Insertion sort vs Bubble Sort Algorithms

Insertion Sort

After i iterations the first i elements are ordered.

In each iteration the next element is bubbled through the sorted section until it reaches the right spot:

sorted  | unsorted
1 3 5 8 | 4 6 7 9 2
1 3 4 5 8 | 6 7 9 2

The 4 is bubbled into the sorted section

Pseudocode:

for i in 1 to n
    for j in i downto 2
        if array[j - 1] > array[j]
            swap(array[j - 1], array[j])
        else
            break

Bubble Sort

After i iterations the last i elements are the biggest, and ordered.

In each iteration, sift through the unsorted section to find the maximum.

unsorted  | biggest
3 1 5 4 2 | 6 7 8 9
1 3 4 2 | 5 6 7 8 9

The 5 is bubbled out of the unsorted section

Pseudocode:

for i in 1 to n
    for j in 1 to n - i
         if array[j] > array[j + 1]
             swap(array[j], array[j + 1])

Note that typical implementations terminate early if no swaps are made during one of the iterations of the outer loop (since that means the array is sorted).

Difference

In insertion sort elements are bubbled into the sorted section, while in bubble sort the maximums are bubbled out of the unsorted section.

Hive External Table Skip First Row

Just append below property in your query and the first header or line int the record will not load or it will be skipped.

Try this

tblproperties ("skip.header.line.count"="1");

Node.js global variables

In Node.js, you can set global variables via the "global" or "GLOBAL" object:

GLOBAL._ = require('underscore'); // But you "shouldn't" do this! (see note below)

or more usefully...

GLOBAL.window = GLOBAL;  // Like in the browser

From the Node.js source, you can see that these are aliased to each other:

node-v0.6.6/src/node.js:
28:     global = this;
128:    global.GLOBAL = global;

In the code above, "this" is the global context. With the CommonJS module system (which Node.js uses), the "this" object inside of a module (i.e., "your code") is not the global context. For proof of this, see below where I spew the "this" object and then the giant "GLOBAL" object.

console.log("\nTHIS:");
console.log(this);
console.log("\nGLOBAL:");
console.log(global);

/* Outputs ...

THIS:
{}

GLOBAL:
{ ArrayBuffer: [Function: ArrayBuffer],
  Int8Array: { [Function] BYTES_PER_ELEMENT: 1 },
  Uint8Array: { [Function] BYTES_PER_ELEMENT: 1 },
  Int16Array: { [Function] BYTES_PER_ELEMENT: 2 },
  Uint16Array: { [Function] BYTES_PER_ELEMENT: 2 },
  Int32Array: { [Function] BYTES_PER_ELEMENT: 4 },
  Uint32Array: { [Function] BYTES_PER_ELEMENT: 4 },
  Float32Array: { [Function] BYTES_PER_ELEMENT: 4 },
  Float64Array: { [Function] BYTES_PER_ELEMENT: 8 },
  DataView: [Function: DataView],
  global: [Circular],
  process:
   { EventEmitter: [Function: EventEmitter],
     title: 'node',
     assert: [Function],
     version: 'v0.6.5',
     _tickCallback: [Function],
     moduleLoadList:
      [ 'Binding evals',
        'Binding natives',
        'NativeModule events',
        'NativeModule buffer',
        'Binding buffer',
        'NativeModule assert',
        'NativeModule util',
        'NativeModule path',
        'NativeModule module',
        'NativeModule fs',
        'Binding fs',
        'Binding constants',
        'NativeModule stream',
        'NativeModule console',
        'Binding tty_wrap',
        'NativeModule tty',
        'NativeModule net',
        'NativeModule timers',
        'Binding timer_wrap',
        'NativeModule _linklist' ],
     versions:
      { node: '0.6.5',
        v8: '3.6.6.11',
        ares: '1.7.5-DEV',
        uv: '0.6',
        openssl: '0.9.8n' },
     nextTick: [Function],
     stdout: [Getter],
     arch: 'x64',
     stderr: [Getter],
     platform: 'darwin',
     argv: [ 'node', '/workspace/zd/zgap/darwin-js/index.js' ],
     stdin: [Getter],
     env:
      { TERM_PROGRAM: 'iTerm.app',
        'COM_GOOGLE_CHROME_FRAMEWORK_SERVICE_PROCESS/USERS/DDOPSON/LIBRARY/APPLICATION_SUPPORT/GOOGLE/CHROME_SOCKET': '/tmp/launch-nNl1vo/ServiceProcessSocket',
        TERM: 'xterm',
        SHELL: '/bin/bash',
        TMPDIR: '/var/folders/2h/2hQmtmXlFT4yVGtr5DBpdl9LAiQ/-Tmp-/',
        Apple_PubSub_Socket_Render: '/tmp/launch-9Ga0PT/Render',
        USER: 'ddopson',
        COMMAND_MODE: 'unix2003',
        SSH_AUTH_SOCK: '/tmp/launch-sD905b/Listeners',
        __CF_USER_TEXT_ENCODING: '0x12D732E7:0:0',
        PATH: '/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:~/bin:/usr/X11/bin',
        PWD: '/workspace/zd/zgap/darwin-js',
        LANG: 'en_US.UTF-8',
        ITERM_PROFILE: 'Default',
        SHLVL: '1',
        COLORFGBG: '7;0',
        HOME: '/Users/ddopson',
        ITERM_SESSION_ID: 'w0t0p0',
        LOGNAME: 'ddopson',
        DISPLAY: '/tmp/launch-l9RQXI/org.x:0',
        OLDPWD: '/workspace/zd/zgap/darwin-js/external',
        _: './index.js' },
     openStdin: [Function],
     exit: [Function],
     pid: 10321,
     features:
      { debug: false,
        uv: true,
        ipv6: true,
        tls_npn: false,
        tls_sni: true,
        tls: true },
     kill: [Function],
     execPath: '/usr/local/bin/node',
     addListener: [Function],
     _needTickCallback: [Function],
     on: [Function],
     removeListener: [Function],
     reallyExit: [Function],
     chdir: [Function],
     debug: [Function],
     error: [Function],
     cwd: [Function],
     watchFile: [Function],
     umask: [Function],
     getuid: [Function],
     unwatchFile: [Function],
     mixin: [Function],
     setuid: [Function],
     setgid: [Function],
     createChildProcess: [Function],
     getgid: [Function],
     inherits: [Function],
     _kill: [Function],
     _byteLength: [Function],
     mainModule:
      { id: '.',
        exports: {},
        parent: null,
        filename: '/workspace/zd/zgap/darwin-js/index.js',
        loaded: false,
        exited: false,
        children: [],
        paths: [Object] },
     _debugProcess: [Function],
     dlopen: [Function],
     uptime: [Function],
     memoryUsage: [Function],
     uvCounters: [Function],
     binding: [Function] },
  GLOBAL: [Circular],
  root: [Circular],
  Buffer:
   { [Function: Buffer]
     poolSize: 8192,
     isBuffer: [Function: isBuffer],
     byteLength: [Function],
     _charsWritten: 8 },
  setTimeout: [Function],
  setInterval: [Function],
  clearTimeout: [Function],
  clearInterval: [Function],
  console: [Getter],
  window: [Circular],
  navigator: {} }
*/

** Note: regarding setting "GLOBAL._", in general you should just do var _ = require('underscore');. Yes, you do that in every single file that uses Underscore.js, just like how in Java you do import com.foo.bar;. This makes it easier to figure out what your code is doing because the linkages between files are 'explicit'. It is mildly annoying, but a good thing. .... That's the preaching.

There is an exception to every rule. I have had precisely exactly one instance where I needed to set "GLOBAL._". I was creating a system for defining "configuration" files which were basically JSON, but were "written in JavaScript" to allow a bit more flexibility. Such configuration files had no 'require' statements, but I wanted them to have access to Underscore.js (the entire system was predicated on Underscore.js and Underscore.js templates), so before evaluating the "configuration", I would set "GLOBAL._". So yeah, for every rule, there's an exception somewhere. But you had better have a darn good reason and not just "I get tired of typing 'require', so I want to break with the convention".

no module named zlib

By default when you configuring Python source, zlib module is disabled, so you can enable it using option --with-zlib when you configure it. So it becomes

./configure --with-zlib

matplotlib set yaxis label size

If you are using the 'pylab' for interactive plotting you can set the labelsize at creation time with pylab.ylabel('Example', fontsize=40).

If you use pyplot programmatically you can either set the fontsize on creation with ax.set_ylabel('Example', fontsize=40) or afterwards with ax.yaxis.label.set_size(40).

Case-insensitive search in Rails model

So far, I made a solution using Ruby. Place this inside the Product model:

  #return first of matching products (id only to minimize memory consumption)
  def self.custom_find_by_name(product_name)
    @@product_names ||= Product.all(:select=>'id, name')
    @@product_names.select{|p| p.name.downcase == product_name.downcase}.first
  end

  #remember a way to flush finder cache in case you run this from console
  def self.flush_custom_finder_cache!
    @@product_names = nil
  end

This will give me the first product where names match. Or nil.

>> Product.create(:name => "Blue jeans")
=> #<Product id: 303, name: "Blue jeans">

>> Product.custom_find_by_name("Blue Jeans")
=> nil

>> Product.flush_custom_finder_cache!
=> nil

>> Product.custom_find_by_name("Blue Jeans")
=> #<Product id: 303, name: "Blue jeans">
>>
>> #SUCCESS! I found you :)

How do I use Assert.Throws to assert the type of the exception?

You can now use the ExpectedException attributes, e.g.

[Test]
[ExpectedException(typeof(InvalidOperationException), 
 ExpectedMessage="You can't do that!"]
public void MethodA_WithNull_ThrowsInvalidOperationException()
{
    MethodA(null);
}

Convert a string to an enum in C#

If the property name is different from what you want to call it (i.e. language differences) you can do like this:

MyType.cs

using System;
using System.Runtime.Serialization;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;

[JsonConverter(typeof(StringEnumConverter))]
public enum MyType
{
    [EnumMember(Value = "person")]
    Person,
    [EnumMember(Value = "annan_deltagare")]
    OtherPerson,
    [EnumMember(Value = "regel")]
    Rule,
}

EnumExtensions.cs

using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;

public static class EnumExtensions
{
    public static TEnum ToEnum<TEnum>(this string value) where TEnum : Enum
    {
        var jsonString = $"'{value.ToLower()}'";
        return JsonConvert.DeserializeObject<TEnum>(jsonString, new StringEnumConverter());
    }

    public static bool EqualsTo<TEnum>(this string strA, TEnum enumB) where TEnum : Enum
    {
        TEnum enumA;
        try
        {
            enumA = strA.ToEnum<TEnum>();
        }
        catch
        {
            return false;
        }
        return enumA.Equals(enumB);
    }
}

Program.cs

public class Program
{
    static public void Main(String[] args) 
    { 
        var myString = "annan_deltagare";
        var myType = myString.ToEnum<MyType>();
        var isEqual = myString.EqualsTo(MyType.OtherPerson);
        //Output: true
    }     
}

Switch statement for greater-than/less-than

I hate using 30 if statements

I had the same situation lately, that's how I solved it:

before:

if(wind_speed >= 18) {
    scale = 5;
} else if(wind_speed >= 12) {
    scale = 4;
} else if(wind_speed >= 9) {
    scale = 3;
} else if(wind_speed >= 6) {
    scale = 2;
} else if(wind_speed >= 4) {
    scale = 1;
}

after:

var scales = [[4, 1], [6, 2], [9, 3], [12, 4], [18, 5]];
scales.forEach(function(el){if(wind_speed > el[0]) scale = el[1]});

And if you set "1, 2, 3, 4, 5" then it can be even simpler:

var scales = [4, 6, 9, 12, 18];
scales.forEach(function(el){if(wind_speed >= el) scale++});

What does "O(1) access time" mean?

O(1) means the time to access something is independent of the number of items in the collection.

O(N) would mean the time to access an item is a proportional to the number (N) of items in the collection.

Selecting multiple items in ListView

and to get it :

public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

                Log.d(getLocalClassName(), "onItemClick(" + view + ","
                        + position + "," + id + ")");
        }
    });

Date in to UTC format Java

Try this... Worked for me and printed 10/22/2013 01:37:56 AM Ofcourse this is your code only with little modifications.

final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
sdf.setTimeZone(TimeZone.getTimeZone("UTC"));   // This line converts the given date into UTC time zone
final java.util.Date dateObj = sdf.parse("2013-10-22T01:37:56");

aRevisedDate = new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a").format(dateObj);
System.out.println(aRevisedDate);

Elasticsearch difference between MUST and SHOULD bool query

As said in the documentation:

Must: The clause (query) must appear in matching documents.

Should: The clause (query) should appear in the matching document. In a boolean query with no must clauses, one or more should clauses must match a document. The minimum number of should clauses to match can be set using the minimum_should_match parameter.

In other words, results will have to be matched by all the queries present in the must clause ( or match at least one of the should clauses if there is no must clause.

Since you want your results to satisfy all the queries, you should use must.


You can indeed use filters inside a boolean query.

iterating through Enumeration of hastable keys throws NoSuchElementException error

You're calling nextElement twice in the loop. You should call it only once, else it moves ahead twice:

while(e.hasMoreElements()){
    String s = e.nextElement();
    System.out.println(s);
}

Convert object of any type to JObject with Json.NET

If you have an object and wish to become JObject you can use:

JObject o = (JObject)JToken.FromObject(miObjetoEspecial);

like this :

Pocion pocionDeVida = new Pocion{
tipo = "vida",
duracion = 32,
};

JObject o = (JObject)JToken.FromObject(pocionDeVida);
Console.WriteLine(o.ToString());
// {"tipo": "vida", "duracion": 32,}

Jenkins: Cannot define variable in pipeline stage

I think error is not coming from the specified line but from the first 3 lines. Try this instead :

node {
   stage("first") {
     def foo = "foo"
     sh "echo ${foo}"
   }
}

I think you had some extra lines that are not valid...

From declaractive pipeline model documentation, it seems that you have to use an environment declaration block to declare your variables, e.g.:

pipeline {
   environment {
     FOO = "foo"
   }

   agent none
   stages {
       stage("first") {
           sh "echo ${FOO}"
       }
   }
}

java.net.ConnectException: Connection refused

One point that I would like to add to the answers above is my experience-

"I hosted on my server on localhost and was trying to connect to it through an android emulator by specifying proper URL like http://localhost/my_api/login.php . And I was getting connection refused error"

Point to note - When I just went to browser on the PC and use the same URL (http://localhost/my_api/login.php) I was getting correct response

so the Problem in my case was the term localhost which I replaced with the IP for my server (as your server is hosted on your machine) which made it reachable from my emulator on the same PC.


To get IP for your local machine, you can use ipconfig command on cmd you will get IPv4 something like 192.68.xx.yy Voila ..that's your machine's IP where you have your server hosted. use it then instead of localhost

http://192.168.72.66/my_api/login.php


Note - you won't be able to reach this private IP from any node outside this computer. (In case you need ,you can use Ngnix for that)

Convert string in base64 to image and save on filesystem in Python

Starting with

img_data = b'iVBORw0KGgoAAAANSUhEUgAABoIAAAaCCAYAAAABZu+EAAAqOElEQVR42uzBAQEAAACAkP6v7ggK\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACA2YMDAQAAAAAg\n/9dGUFVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV\nVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVWkPDgkA\nAAAABP1/7QobAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\nAAAAAAAAAAAAAAAAAIcAeHkAAeLqlDIAAAAASUVORK5CYII='

Decoded the data using the base64 codec, and then write it to the filesystem.

# In Python 2.7
fh = open("imageToSave.png", "wb")
fh.write(img_data.decode('base64'))
fh.close()

# or, more concisely using with statement
with open("imageToSave.png", "wb") as fh:
    fh.write(img_data.decode('base64'))

Modernizing this example to Python 3, which removed arbitrary codec support from string/bytes .encode() and .decode() functions:

# For both Python 2.7 and Python 3.x
import base64
with open("imageToSave.png", "wb") as fh:
    fh.write(base64.decodebytes(img_data))

How to save all console output to file in R?

If you are able to use the bash shell, you can consider simply running the R code from within a bash script and piping the stdout and stderr streams to a file. Here is an example using a heredoc:

File: test.sh

#!/bin/bash
# this is a bash script
echo "Hello World, this is bash"

test1=$(echo "This is a test")

echo "Here is some R code:"

Rscript --slave --no-save --no-restore - "$test1" <<EOF
  ## R code
  cat("\nHello World, this is R\n")
  args <- commandArgs(TRUE)
  bash_message<-args[1]
  cat("\nThis is a message from bash:\n")
  cat("\n",paste0(bash_message),"\n")
EOF

# end of script 

Then when you run the script with both stderr and stdout piped to a log file:

$ chmod +x test.sh
$ ./test.sh
$ ./test.sh &>test.log
$ cat test.log
Hello World, this is bash
Here is some R code:

Hello World, this is R

This is a message from bash:

 This is a test

Other things to look at for this would be to try simply pipping the stdout and stderr right from the R heredoc into a log file; I haven't tried this yet but it will probably work too.

python re.split() to split by spaces, commas, and periods, but not in cases like 1,000 or 1.50

Use a negative lookahead and a negative lookbehind:

> s = "one two 3.4 5,6 seven.eight nine,ten"
> parts = re.split('\s|(?<!\d)[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten']

In other words, you always split by \s (whitespace), and only split by commas and periods if they are not followed (?!\d) or preceded (?<!\d) by a digit.

DEMO.

EDIT: As per @verdesmarald comment, you may want to use the following instead:

> s = "one two 3.4 5,6 seven.eight nine,ten,1.2,a,5"
> print re.split('\s|(?<!\d)[,.]|[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten', '1.2', 'a', '5']

This will split "1.2,a,5" into ["1.2", "a", "5"].

DEMO.

How can I align button in Center or right using IONIC framework?

And if we want to align a checkbox to the right, we can use item-end.

<ion-checkbox checked="true" item-end></ion-checkbox>

Python: avoiding pylint warnings about too many arguments

Python has some nice functional programming tools that are likely to fit your needs well. Check out lambda functions and map. Also, you're using dicts when it seems like you'd be much better served with lists. For the simple example you provided, try this idiom. Note that map would be better and faster but may not fit your needs:

def mysum(d):
   s = 0  
   for x in d:
        s += x
   return s

def mybigfunction():
   d = (x1, x2, x3, x4, x5, x6, x7, x8, x9)
   return mysum(d)

You mentioned having a lot of local variables, but frankly if you're dealing with lists (or tuples), you should use lists and factor out all those local variables in the long run.

jQuery get mouse position within an element

I would suggest this:

e.pageX - this.getBoundingClientRect().left

Convert HTML string to image

Try the following:

using System;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;

class Program
{
    static void Main(string[] args)
    {
        var source =  @"
        <!DOCTYPE html>
        <html>
            <body>
                <p>An image from W3Schools:</p>
                <img 
                    src=""http://www.w3schools.com/images/w3schools_green.jpg"" 
                    alt=""W3Schools.com"" 
                    width=""104"" 
                    height=""142"">
            </body>
        </html>";
        StartBrowser(source);
        Console.ReadLine();
    }

    private static void StartBrowser(string source)
    {
        var th = new Thread(() =>
        {
            var webBrowser = new WebBrowser();
            webBrowser.ScrollBarsEnabled = false;
            webBrowser.DocumentCompleted +=
                webBrowser_DocumentCompleted;
            webBrowser.DocumentText = source;
            Application.Run();
        });
        th.SetApartmentState(ApartmentState.STA);
        th.Start();
    }

    static void 
        webBrowser_DocumentCompleted(
        object sender, 
        WebBrowserDocumentCompletedEventArgs e)
    {
        var webBrowser = (WebBrowser)sender;
        using (Bitmap bitmap = 
            new Bitmap(
                webBrowser.Width, 
                webBrowser.Height))
        {
            webBrowser
                .DrawToBitmap(
                bitmap, 
                new System.Drawing
                    .Rectangle(0, 0, bitmap.Width, bitmap.Height));
            bitmap.Save(@"filename.jpg", 
                System.Drawing.Imaging.ImageFormat.Jpeg);
        }
    }
}

Note: Credits should go to Hans Passant for his excellent answer on the question WebBrowser Control in a new thread which inspired this solution.

Difference between Grunt, NPM and Bower ( package.json vs bower.json )

Npm and Bower are both dependency management tools. But the main difference between both is npm is used for installing Node js modules but bower js is used for managing front end components like html, css, js etc.

A fact that makes this more confusing is that npm provides some packages which can be used in front-end development as well, like grunt and jshint.

These lines add more meaning

Bower, unlike npm, can have multiple files (e.g. .js, .css, .html, .png, .ttf) which are considered the main file(s). Bower semantically considers these main files, when packaged together, a component.

Edit: Grunt is quite different from Npm and Bower. Grunt is a javascript task runner tool. You can do a lot of things using grunt which you had to do manually otherwise. Highlighting some of the uses of Grunt:

  1. Zipping some files (e.g. zipup plugin)
  2. Linting on js files (jshint)
  3. Compiling less files (grunt-contrib-less)

There are grunt plugins for sass compilation, uglifying your javascript, copy files/folders, minifying javascript etc.

Please Note that grunt plugin is also an npm package.

Question-1

When I want to add a package (and check in the dependency into git), where does it belong - into package.json or into bower.json

It really depends where does this package belong to. If it is a node module(like grunt,request) then it will go in package.json otherwise into bower json.

Question-2

When should I ever install packages explicitly like that without adding them to the file that manages dependencies

It does not matter whether you are installing packages explicitly or mentioning the dependency in .json file. Suppose you are in the middle of working on a node project and you need another project, say request, then you have two options:

  • Edit the package.json file and add a dependency on 'request'
  • npm install

OR

  • Use commandline: npm install --save request

--save options adds the dependency to package.json file as well. If you don't specify --save option, it will only download the package but the json file will be unaffected.

You can do this either way, there will not be a substantial difference.

SQL: Alias Column Name for Use in CASE Statement

  • If you write only equal condition just: Select Case columns1 When 0 then 'Value1' when 1 then 'Value2' else 'Unknown' End

  • If you want to write greater , Less then or equal you must do like this: Select Case When [ColumnsName] >0 then 'value1' When [ColumnsName]=0 Or [ColumnsName]<0 then 'value2' Else 'Unkownvalue' End

From tablename

Thanks Mr.Buntha Khin

Basic authentication for REST API using spring restTemplate

Reference Spring Boot's TestRestTemplate implementation as follows:

https://github.com/spring-projects/spring-boot/blob/v1.2.2.RELEASE/spring-boot/src/main/java/org/springframework/boot/test/TestRestTemplate.java

Especially, see the addAuthentication() method as follows:

private void addAuthentication(String username, String password) {
    if (username == null) {
        return;
    }
    List<ClientHttpRequestInterceptor> interceptors = Collections
            .<ClientHttpRequestInterceptor> singletonList(new BasicAuthorizationInterceptor(
                    username, password));
    setRequestFactory(new InterceptingClientHttpRequestFactory(getRequestFactory(),
            interceptors));
}

Similarly, you can make your own RestTemplate easily

by inheritance like TestRestTemplate as follows:

https://github.com/izeye/samples-spring-boot-branches/blob/rest-and-actuator-with-security/src/main/java/samples/springboot/util/BasicAuthRestTemplate.java

How to access a value defined in the application.properties file in Spring Boot

The best thing is to use @Value annotation it will automatically assign value to your object private Environment en. This will reduce your code and it will be easy to filter your files.

Bootstrap: Use .pull-right without having to hardcode a negative margin-top

Keep the h2 at the top, then pull-left on the p and pull-right on the login-box

<div class='container'>
  <div class='hero-unit'>

    <h2>Welcome</h2>

    <div class="pull-left">
      <p>Please log in</p>
    </div>

    <div id='login-box' class='pull-right control-group'>
        <div class='clearfix'>
            <input type='text' placeholder='Username' />
        </div>
        <div class='clearfix'>
            <input type='password' placeholder='Password' />
        </div>
        <button type='button' class='btn btn-primary'>Log in</button>
    </div>

    <div class="clearfix"></div>

  </div>
</div>

the default vertical-align on floated boxes is baseline, so the "Please log in" exactly lines up with the "Username" (check by changing the pull-right to pull-left).

Writing .csv files from C++

If you wirte to a .csv file in C++ - you should use the syntax of :

myfile <<" %s; %s; %d", string1, string2, double1 <<endl;

This will write the three variables (string 1&2 and double1) into separate columns and leave an empty row below them. In excel the ; means the new row, so if you want to just take a new row - you can alos write a simple ";" before writing your new data into the file. If you don't want to have an empty row below - you should delete the endl and use the:

myfile.open("result.csv", std::ios::out | std::ios::app);

syntax when opening the .csv file (example the result.csv). In this way next time you write something into your result.csv file - it will write it into a new row directly below the last one - so you can easily manage a for cycle if you would like to.

Difference between Parameters.Add(string, object) and Parameters.AddWithValue

When we use CommandObj.Parameter.Add() it takes 2 parameters, the first is procedure parameter and the second is its data type, while .AddWithValue() takes 2 parameters, the first is procedure parameter and the second is the data variable

CommandObj.Parameter.Add("@ID",SqlDbType.Int).Value=textBox1.Text;

for .AddWithValue

CommandObj.Parameter.AddWitheValue("@ID",textBox1.Text);

where ID is the parameter of stored procedure which data type is Int

How do I find the size of a struct?

#include <stdio.h>

typedef struct { char* c; char b; } a;

int main()
{
    printf("sizeof(a) == %d", sizeof(a));
}

I get "sizeof(a) == 8", on a 32-bit machine. The total size of the structure will depend on the packing: In my case, the default packing is 4, so 'c' takes 4 bytes, 'b' takes one byte, leaving 3 padding bytes to bring it to the next multiple of 4: 8. If you want to alter this packing, most compilers have a way to alter it, for example, on MSVC:

#pragma pack(1)
typedef struct { char* c; char b; } a;

gives sizeof(a) == 5. If you do this, be careful to reset the packing before any library headers!

Simple logical operators in Bash

Here is the code for the short version of if-then-else statement:

( [ $a -eq 1 ] || [ $b -eq 2 ] ) && echo "ok" || echo "nok"

Pay attention to the following:

  1. || and && operands inside if condition (i.e. between round parentheses) are logical operands (or/and)

  2. || and && operands outside if condition mean then/else

Practically the statement says:

if (a=1 or b=2) then "ok" else "nok"

HowTo Generate List of SQL Server Jobs and their owners

If you don't have access to sysjobs table (someone elses server etc) you might be have or be allowed access to sysjobs_view

SELECT *
 from  msdb..sysjobs_view s 
 left join master.sys.syslogins l on s.owner_sid = l.sid

or

SELECT *, SUSER_SNAME(s.owner_sid) AS owner
 from  msdb..sysjobs_view s 

Error: " 'dict' object has no attribute 'iteritems' "

As answered by RafaelC, Python 3 renamed dict.iteritems -> dict.items. Try a different package version. This will list available packages:

python -m pip install yourOwnPackageHere==

Then rerun with the version you will try after == to install/switch version

Where is Maven's settings.xml located on Mac OS?

If you use brew to install maven, then the settings file should be in

/usr/local/Cellar/maven/<version>/libexec/conf

Python Prime number checker

def is_prime(n):
    return all(n%j for j in xrange(2, int(n**0.5)+1)) and n>1

How can I override the OnBeforeUnload dialog and replace it with my own?

What worked for me, using jQuery and tested in IE8, Chrome and Firefox, is:

$(window).bind("beforeunload",function(event) {
    if(hasChanged) return "You have unsaved changes";
});

It is important not to return anything if no prompt is required as there are differences between IE and other browser behaviours here.

On select change, get data attribute value

this works for me

<select class="form-control" id="foo">
    <option value="first" data-id="1">first</option>
    <option value="second" data-id="2">second</option>
</select>

and the script

$('#foo').on("change",function(){
    var dataid = $("#foo option:selected").attr('data-id');
    alert(dataid)
});

ReactJS - Add custom event listener to component

You could use componentDidMount and componentWillUnmount methods:

import React, { Component } from 'react';
import ReactDOM from 'react-dom';

class MovieItem extends Component
{
    _handleNVEvent = event => {
        ...
    };

    componentDidMount() {
        ReactDOM.findDOMNode(this).addEventListener('nv-event', this._handleNVEvent);
    }

    componentWillUnmount() {
        ReactDOM.findDOMNode(this).removeEventListener('nv-event', this._handleNVEvent);
    }

    [...]

}

export default MovieItem;

How to show uncommitted changes in Git and some Git diffs in detail

You have already staged the changes (presumably by running git add), so in order to get their diff, you need to run:

git diff --cached

(A plain git diff will only show unstaged changes.)

For example: Example git diff cached use

ASP.NET Identity reset password

On your UserManager, first call GeneratePasswordResetTokenAsync. Once the user has verified his identity (for example by receiving the token in an email), pass the token to ResetPasswordAsync.

Number of lines in a file in Java

The answer with the method count() above gave me line miscounts if a file didn't have a newline at the end of the file - it failed to count the last line in the file.

This method works better for me:

public int countLines(String filename) throws IOException {
    LineNumberReader reader  = new LineNumberReader(new FileReader(filename));
int cnt = 0;
String lineRead = "";
while ((lineRead = reader.readLine()) != null) {}

cnt = reader.getLineNumber(); 
reader.close();
return cnt;
}

ImportError: No module named enum

Depending on your rights, you need sudo at beginning.

What is the purpose of a plus symbol before a variable?

Operator + is a unary operator which converts value to number. Below I prepared a table with corresponding results of using this operator for different values.

+-----------------------------+-----------+
| Value                       | + (Value) |
+-----------------------------+-----------+
| 1                           | 1         |
| '-1'                        | -1        |
| '3.14'                      | 3.14      |
| '3'                         | 3         |
| '0xAA'                      | 170       |
| true                        | 1         |
| false                       | 0         |
| null                        | 0         |
| 'Infinity'                  | Infinity  |
| 'infinity'                  | NaN       |
| '10a'                       | NaN       |
| undefined                   | Nan       |
| ['Apple']                   | Nan       |
| function(val){ return val } | NaN       |
+-----------------------------+-----------+

Operator + returns value for objects which have implemented method valueOf.

let something = {
    valueOf: function () {
        return 25;
    }
};

console.log(+something);

Set up a scheduled job?

Celery is a distributed task queue, built on AMQP (RabbitMQ). It also handles periodic tasks in a cron-like fashion (see periodic tasks). Depending on your app, it might be worth a gander.

Celery is pretty easy to set up with django (docs), and periodic tasks will actually skip missed tasks in case of a downtime. Celery also has built-in retry mechanisms, in case a task fails.

QLabel: set color of text and background

I add this answer because I think it could be useful to anybody.

I step into the problem of setting RGBA colors (that is, RGB color with an Alpha value for transparency) for color display labels in my painting application.

As I came across the first answer, I was unable to set an RGBA color. I have also tried things like:

myLabel.setStyleSheet("QLabel { background-color : %s"%color.name())

where color is an RGBA color.

So, my dirty solution was to extend QLabel and override paintEvent() method filling its bounding rect.

Today, I've open up the qt-assistant and read the style reference properties list. Affortunately, it has an example that states the following:

QLineEdit { background-color: rgb(255, 0, 0) }

Thats open up my mind in doing something like the code below, as an example:

myLabel= QLabel()
myLabel.setAutoFillBackground(True) # This is important!!
color  = QtGui.QColor(233, 10, 150)
alpha  = 140
values = "{r}, {g}, {b}, {a}".format(r = color.red(),
                                     g = color.green(),
                                     b = color.blue(),
                                     a = alpha
                                     )
myLabel.setStyleSheet("QLabel { background-color: rgba("+values+"); }")

Note that setAutoFillBackground() set in False will not make it work.

Regards,

How do I reference to another (open or closed) workbook, and pull values back, in VBA? - Excel 2007

You will have to open the file in one way or another if you want to access the data within it. Obviously, one way is to open it in your Excel application instance, e.g.:-

(untested code)

Dim wbk As Workbook
Set wbk = Workbooks.Open("C:\myworkbook.xls")

' now you can manipulate the data in the workbook anyway you want, e.g. '

Dim x As Variant
x = wbk.Worksheets("Sheet1").Range("A6").Value

Call wbk.Worksheets("Sheet2").Range("A1:G100").Copy
Call ThisWorbook.Worksheets("Target").Range("A1").PasteSpecial(xlPasteValues)
Application.CutCopyMode = False

' etc '

Call wbk.Close(False)

Another way to do it would be to use the Excel ADODB provider to open a connection to the file and then use SQL to select data from the sheet you want, but since you are anyway working from within Excel I don't believe there is any reason to do this rather than just open the workbook. Note that there are optional parameters for the Workbooks.Open() method to open the workbook as read-only, etc.

How to add element in List while iterating in java?

Iterate through a copy of the list and add new elements to the original list.

for (String s : new ArrayList<String>(list))     
{
    list.add("u");
}

See How to make a copy of ArrayList object which is type of List?

Where can I find Android's default icons?

\path-to-your-android-sdk-folder\platforms\android-xx\data\res

How to add target="_blank" to JavaScript window.location?

I have created a function that allows me to obtain this feature:

function redirect_blank(url) {
  var a = document.createElement('a');
  a.target="_blank";
  a.href=url;
  a.click();
}

What is the best JavaScript code to create an img element

var img = document.createElement('img');
img.src = 'my_image.jpg';
document.getElementById('container').appendChild(img);

Writing JSON object to a JSON file with fs.writeFileSync

Here's a variation, using the version of fs that uses promises:

const fs = require('fs');

await fs.promises.writeFile('../data/phraseFreqs.json', JSON.stringify(output)); // UTF-8 is default

How to semantically add heading to a list

According to w3.org (note that this link is in the long-expired draft HTML 3.0 spec):

An unordered list typically is a bulleted list of items. HTML 3.0 gives you the ability to customise the bullets, to do without bullets and to wrap list items horizontally or vertically for multicolumn lists.

The opening list tag must be <UL>. It is followed by an optional list header (<LH>caption</LH>) and then by the first list item (<LI>). For example:

<UL>
  <LH>Table Fruit</LH>
  <LI>apples
  <LI>oranges
  <LI>bananas
</UL>

which could be rendered as:

Table Fruit

  • apples
  • oranges
  • bananas

Note: Some legacy documents may include headers or plain text before the first LI element. Implementors of HTML 3.0 user agents are advised to cater for this possibility in order to handle badly formed legacy documents.

Is there a way to comment out markup in an .ASPX page?

While this works:

<%-- <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="ht_tv1.Default" %> --%>
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Blank._Default" %>

This won't.

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" <%--Inherits="ht_tv1.Default"--%> Inherits="Blank._Default" %>

So you can't comment out part of something which is what I want to do 99.9995% of the time.

CSS selector for text input fields?

The attribute selectors are often used for inputs. This is the list of attribute selectors:

[title] All elements with the title attribute are selected.

[title=banana] All elements which have the 'banana' value of the title attribute.

[title~=banana] All elements which contain 'banana' in the value of the title attribute.

[title|=banana] All elements which value of the title attribute starts with 'banana'.

[title^=banana] All elements which value of the title attribute begins with 'banana'.

[title$=banana] All elements which value of the title attribute ends with 'banana'.

[title*=banana] All elements which value of the title attribute contains the substring 'banana'.

Reference: https://kolosek.com/css-selectors/

Get month and year from date cells Excel

You could right click on those cells, go to format, select custom, then type mm yyyy.

How can I pull from remote Git repository and override the changes in my local repository?

As an addendum, if you want to reapply your changes on top of the remote, you can also try:

git pull --rebase origin master

If you then want to undo some of your changes (but perhaps not all of them) you can use:

git reset SHA_HASH

Then do some adjustment and recommit.

How do I count unique items in field in Access query?

Access-Engine does not support

SELECT count(DISTINCT....) FROM ...

You have to do it like this:

SELECT count(*) 
FROM
(SELECT DISTINCT Name FROM table1)

Its a little workaround... you're counting a DISTINCT selection.

How to copy the first few lines of a giant file, and add a line of text at the end of it using some Linux commands?

The head command can get the first n lines. Variations are:

head -7 file
head -n 7 file
head -7l file

which will get the first 7 lines of the file called "file". The command to use depends on your version of head. Linux will work with the first one.

To append lines to the end of the same file, use:

echo 'first line to add' >>file
echo 'second line to add' >>file
echo 'third line to add' >>file

or:

echo 'first line to add
second line to add
third line to add' >>file

to do it in one hit.

So, tying these two ideas together, if you wanted to get the first 10 lines of the input.txt file to output.txt and append a line with five "=" characters, you could use something like:

( head -10 input.txt ; echo '=====' ) > output.txt

In this case, we do both operations in a sub-shell so as to consolidate the output streams into one, which is then used to create or overwrite the output file.

Convert a String to Modified Camel Case in Java or Title Case as is otherwise called

You can easily write the method to do that :

  public static String toCamelCase(final String init) {
    if (init == null)
        return null;

    final StringBuilder ret = new StringBuilder(init.length());

    for (final String word : init.split(" ")) {
        if (!word.isEmpty()) {
            ret.append(Character.toUpperCase(word.charAt(0)));
            ret.append(word.substring(1).toLowerCase());
        }
        if (!(ret.length() == init.length()))
            ret.append(" ");
    }

    return ret.toString();
}

Automatically creating directories with file output

The os.makedirs function does this. Try the following:

import os
import errno

filename = "/foo/bar/baz.txt"
if not os.path.exists(os.path.dirname(filename)):
    try:
        os.makedirs(os.path.dirname(filename))
    except OSError as exc: # Guard against race condition
        if exc.errno != errno.EEXIST:
            raise

with open(filename, "w") as f:
    f.write("FOOBAR")

The reason to add the try-except block is to handle the case when the directory was created between the os.path.exists and the os.makedirs calls, so that to protect us from race conditions.


In Python 3.2+, there is a more elegant way that avoids the race condition above:

import os

filename = "/foo/bar/baz.txt"
os.makedirs(os.path.dirname(filename), exist_ok=True)
with open(filename, "w") as f:
    f.write("FOOBAR")

Test if string is URL encoded in PHP

What about:

if (urldecode(trim($url)) == trim($url)) { $url_form = 'decoded'; }
  else { $url_form = 'encoded'; }

Will not work with double encoding but this is out of scope anyway I suppose?

Best way to center a <div> on a page vertically and horizontally?

Solution

Using only two lines of CSS, utilizing the magical power of Flexbox

.parent { display: flex; }
.child { margin: auto }

how to fix stream_socket_enable_crypto(): SSL operation failed with code 1

edit your .env and add this line after mail config lines

MAIL_ENCRYPTION=""

Save and try to send email

How to export data from Excel spreadsheet to Sql Server 2008 table

From your SQL Server Management Studio, you open Object Explorer, go to your database where you want to load the data into, right click, then pick Tasks > Import Data.

This opens the Import Data Wizard, which typically works pretty well for importing from Excel. You can pick an Excel file, pick what worksheet to import data from, you can choose what table to store it into, and what the columns are going to be. Pretty flexible indeed.

You can run this as a one-off, or you can store it as a SQL Server Integration Services (SSIS) package into your file system, or into SQL Server itself, and execute it over and over again (even scheduled to run at a given time, using SQL Agent).

Update: yes, yes, yes, you can do all those things you keep asking - have you even tried at least once to run that wizard??

OK, here it comes - step by step:

Step 1: pick your Excel source

enter image description here

Step 2: pick your SQL Server target database

enter image description here

Step 3: pick your source worksheet (from Excel) and your target table in your SQL Server database; see the "Edit Mappings" button!

enter image description here

Step 4: check (and change, if needed) your mappings of Excel columns to SQL Server columns in the table:

enter image description here

Step 5: if you want to use it later on, save your SSIS package to SQL Server:

enter image description here

Step 6: - success! This is on a 64-bit machine, works like a charm - just do it!!

Get the selected option id with jQuery

var id = $(this).find('option:selected').attr('id');

then you do whatever you want with selectedIndex

I've reedited my answer ... since selectedIndex isn't a good variable to give example...

Insert string in beginning of another string

Other answers explain how to insert a string at the beginning of another String or StringBuilder (or StringBuffer).

However, strictly speaking, you cannot insert a string into the beginning of another one. Strings in Java are immutable1.

When you write:

String s = "Jam";
s = "Hello " + s;

you are actually causing a new String object to be created that is the concatenation of "Hello " and "Jam". You are not actually inserting characters into an existing String object at all.


1 - It is technically possible to use reflection to break abstraction on String objects and mutate them ... even though they are immutable by design. But it is a really bad idea to do this. Unless you know that a String object was created explicitly via new String(...) it could be shared, or it could share internal state with other String objects. Finally, the JVM spec clearly states that the behavior of code that uses reflection to change a final is undefined. Mutation of String objects is dangerous.

replace all occurrences in a string

Brighams answer uses literal regexp.

Solution with a Regex object.

var regex = new RegExp('\n', 'g');
text = text.replace(regex, '<br />');

TRY IT HERE : JSFiddle Working Example

Concatenate two char* strings in a C program

strcat attempts to append the second parameter to the first. This won't work since you are assigning implicitly sized constant strings.

If all you want to do is print two strings out

printf("%s%s",str1,str2);

Would do.

You could do something like

char *str1 = calloc(sizeof("SSSS")+sizeof("KKKK")+1,sizeof *str1);
strcpy(str1,"SSSS");
strcat(str1,str2);

to create a concatenated string; however strongly consider using strncat/strncpy instead. And read the man pages carefully for the above. (oh and don't forget to free str1 at the end).

How to set delay in vbscript

if it is VBScript, it should be

WScript.Sleep 100

If it is JavaScript

WScript.Sleep(100);

Time in milliseconds. WScript.Sleep 1000 results in a 1 second sleep.

Keyboard shortcut for Jump to Previous View Location (Navigate back/forward) in IntelliJ IDEA

Alt + Shift + ? (Left Arrow)

or

Ctrl + E (Recent Files pop-up).

Also check:

Ctrl + Shift + E (the Recently Edited Files pop-up).

Mac users, replace Ctrl with ? (command) and Alt with ? (option).

Update In v12.0 it's Alt + Shift +? (Left Arrow) instead of Alt + Ctrl + ? (Left Arrow).

Update 2 In v14.1 (and possibly earlier) it's Ctrl + [

Update 3 In IntelliJ IDEA 2016.3 it's Ctrl + Alt + ? (Left Arrow)

Update 4 In IntelliJ IDEA 2018.3 it's Alt + Shift + ? (Left Arrow)

Update 5 In IntelliJ IDEA 2019.3 it's Ctrl + Alt + ? (Left Arrow)

Array to String PHP?

$data = array("asdcasdc","35353","asdca353sdc","sadcasdc","sadcasdc","asdcsdcsad");

$string_array = json_encode($data);

now you can insert this $string_array value into Database

Disable button in WPF?

I know this isn't as elegant as the other posts, but it's a more straightforward xaml/codebehind example of how to accomplish the same thing.

Xaml:

<StackPanel Orientation="Horizontal">
   <TextBox Name="TextBox01" VerticalAlignment="Top" HorizontalAlignment="Left" Width="70" />
   <Button Name="Button01" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="10,0,0,0" />
</StackPanel>

CodeBehind:

Private Sub Window1_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded

        Button01.IsEnabled = False
        Button01.Content = "I am Disabled"

End Sub

Private Sub TextBox01_TextChanged(ByVal sender As Object, ByVal e As System.Windows.Controls.TextChangedEventArgs) Handles TextBox01.TextChanged

        If TextBox01.Text.Trim.Length > 0 Then
            Button01.IsEnabled = True
            Button01.Content = "I am Enabled"
        Else
            Button01.IsEnabled = False
            Button01.Content = "I am Disabled"
        End If

End Sub

How to get date in BAT file

You get and format like this

for /f "tokens=1-4 delims=/ " %%i in ("%date%") do (
     set dow=%%i
     set month=%%j
     set day=%%k
     set year=%%l
)
set datestr=%month%_%day%_%year%
echo datestr is %datestr%

Note: Above only works on US locale. It assumes the output of echo %date% looks like this: Thu 02/13/21. If you have different Windows locale settings, you will need to modify the script based on your configuration.

Creating a REST API using PHP

In your example, it’s fine as it is: it’s simple and works. The only things I’d suggest are:

  1. validating the data POSTed
  2. make sure your API is sending the Content-Type header to tell the client to expect a JSON response:

    header('Content-Type: application/json');
    echo json_encode($response);
    

Other than that, an API is something that takes an input and provides an output. It’s possible to “over-engineer” things, in that you make things more complicated that need be.

If you wanted to go down the route of controllers and models, then read up on the MVC pattern and work out how your domain objects fit into it. Looking at the above example, I can see maybe a MathController with an add() action/method.

There are a few starting point projects for RESTful APIs on GitHub that are worth a look.

How can you print a variable name in python?

For the revised question of how to read in configuration parameters, I'd strongly recommend saving yourself some time and effort and use ConfigParser or (my preferred tool) ConfigObj.

They can do everything you need, they're easy to use, and someone else has already worried about how to get them to work properly!

Find duplicate records in MySQL

Fastest duplicates removal queries procedure:

/* create temp table with one primary column id */
INSERT INTO temp(id) SELECT MIN(id) FROM list GROUP BY (isbn) HAVING COUNT(*)>1;
DELETE FROM list WHERE id IN (SELECT id FROM temp);
DELETE FROM temp;

How to hide command output in Bash

.SILENT:

Type " .SILENT: " in the beginning of your script without colons.

Rails how to run rake task

In rails 4.2 the above methods didn't work.

  1. Go to the Terminal.
  2. Change the directory to the location where your rake file is present.
  3. run rake task_name.
  4. In the above case, run rake iqmedier - will run only iqmedir task.
  5. run rake euroads - will run only the euroads task.
  6. To Run all the tasks in that file assign the following inside the same file and run rake all

    task :all => [:iqmedier, :euroads, :mikkelsen, :orville ] do #This will print all the tasks o/p on the screen 
    end
    

How do implement a breadth first traversal?

public static boolean BFS(ListNode n, int x){
        if(n==null){
           return false;
       }
Queue<ListNode<Integer>> q = new Queue<ListNode<Integer>>();
ListNode<Integer> tmp = new ListNode<Integer>(); 
q.enqueue(n);
tmp = q.dequeue();
if(tmp.val == x){
    return true;
}
while(tmp != null){
    for(ListNode<Integer> child: n.getChildren()){
        if(child.val == x){
            return true;
        }
        q.enqueue(child);
    }

    tmp = q.dequeue();
}
return false;
}

How to do SVN Update on my project using the command line

svn update /path/to/working/copy

If subversion is not in your PATH, then of course

/path/to/subversion/svn update /path/to/working/copy

or if you are in the current root directory of your svn repo (it contains a .svn subfolder), it's as simple as

svn update

PHP If Statement with Multiple Conditions

you can use in_array function of php

$array=array('abc', 'def', 'hij', 'klm', 'nop');

if (in_array($val,$array))
{
  echo 'Value found';
}

CSS Select box arrow style

Try to replace the

padding: 2px 30px 2px 2px;

with

padding: 2px 2px 2px 2px;

It should work.

Timestamp with a millisecond precision: How to save them in MySQL

CREATE TABLE fractest( c1 TIME(3), c2 DATETIME(3), c3 TIMESTAMP(3) );

INSERT INTO fractest VALUES
('17:51:04.777', '2018-09-08 17:51:04.777', '2018-09-08 17:51:04.777');

Fatal error: Class 'Illuminate\Foundation\Application' not found

In my case composer was not installed in that directory. So I run

composer install

then error resolved.

or you can try

composer update --no-scripts
cd bootstrap/cache/->rm -rf *.php
composer dump-autoload

How to remove the last character from a bash grep output

Assuming the quotation marks are actually part of the output, couldn't you just use the -o switch to return everything between the quote marks?

COMPANY_NAME="\"ABC Inc\";" | echo $COMPANY_NAME | grep -o "\"*.*\""

Responsive background image in div full width

Here is one way of getting the design that you want.

Start with the following HTML:

<div class="container">
    <div class="row-fluid">
        <div class="span12">
            <div class="nav">nav area</div>
            <div class="bg-image">
                <img src="http://unplugged.ee/wp-content/uploads/2013/03/frank2.jpg">
                 <h1>This is centered text.</h1>
            </div>
            <div class="main">main area</div>
        </div>
    </div>
</div>

Note that the background image is now part of the regular flow of the document.

Apply the following CSS:

.bg-image {
    position: relative;
}
.bg-image img {
    display: block;
    width: 100%;
    max-width: 1200px; /* corresponds to max height of 450px */
    margin: 0 auto;
}
.bg-image h1 {
    position: absolute;
    text-align: center;
    bottom: 0;
    left: 0;
    right: 0;
    color: white;
}
.nav, .main {
    background-color: #f6f6f6;
    text-align: center;
}

How This Works

The image is set an regular flow content with a width of 100%, so it will adjust itself responsively to the width of the parent container. However, you want the height to be no more than 450px, which corresponds to the image width of 1200px, so set the maximum width of the image to 1200px. You can keep the image centered by using display: block and margin: 0 auto.

The text is painted over the image by using absolute positioning. In the simplest case, I stretch the h1 element to be the full width of the parent and use text-align: center to center the text. Use the top or bottom offsets to place the text where it is needed.

If your banner images are going to vary in aspect ratio, you will need to adjust the maximum width value for .bg-image img dynamically using jQuery/Javascript, but otherwise, this approach has a lot to offer.

See demo at: http://jsfiddle.net/audetwebdesign/EGgaN/

What is the main purpose of setTag() getTag() methods of View?

Setting of TAGs is really useful when you have a ListView and want to recycle/reuse the views. In that way the ListView is becoming very similar to the newer RecyclerView.

@Override
public View getView(int position, View convertView, ViewGroup parent)
  {
ViewHolder holder = null;

if ( convertView == null )
{
    /* There is no view at this position, we create a new one. 
       In this case by inflating an xml layout */
    convertView = mInflater.inflate(R.layout.listview_item, null);  
    holder = new ViewHolder();
    holder.toggleOk = (ToggleButton) convertView.findViewById( R.id.togOk );
    convertView.setTag (holder);
}
else
{
    /* We recycle a View that already exists */
    holder = (ViewHolder) convertView.getTag ();
}

// Once we have a reference to the View we are returning, we set its values.

// Here is where you should set the ToggleButton value for this item!!!

holder.toggleOk.setChecked( mToggles.get( position ) );

return convertView;
}

Can not run Java Applets in Internet Explorer 11 using JRE 7u51

I've just resolved the problem on two PCs (Win 8 64-bit with IE10; Win 8.1 32-bit with IE11). With Java 7 Update 67 both cases (same with update 65 and, probably, others).

In my case, it was caused by java ssv, which first requested admin rights, then Java stopped working because it messed something using them.

So, my resolution was:

  1. Reinstall java. No reboot required, but close browsers beforehand. Also, it's not required to uninstall it before running installer (I didn't).
  2. On 1st (or 2nd) launch of IE, privilege elevation will be prompted for Java SSV. If denied, it will pop up again. Multiple times. Important here is to deny them all.
  3. To stop these prompts, disable Java SSV helpers (both of them) in Add-Ons or when IE prompts about startup times. IE Add-ons manager, Java Plug-In SSV helpers disabled

After that, http://www.java.com/verify/ prompts to run Java (twice, 1st time IE, 2nd time Java itself) and, when allowed, says everything is OK.

(will give more screenshots if anyone will ask)

How to adjust an UIButton's imageSize?

With the help of Tim C's answer, I was able to create an extension on UIButton using Swift that allows you to specify the image frame by using the .setImage() function with an extra frame parameter

extension UIButton{

    func setImage(image: UIImage?, inFrame frame: CGRect?, forState state: UIControlState){
        self.setImage(image, forState: state)

        if let frame = frame{
            self.imageEdgeInsets = UIEdgeInsets(
                top: frame.minY - self.frame.minY,
                left: frame.minX - self.frame.minX,
                bottom: self.frame.maxY - frame.maxY,
                right: self.frame.maxX - frame.maxX
            )
        }
    }

}

Using this, if you wanted to set the frame of a UIButton to CGRectMake(0, 0, 64, 64), and set the image of it to myImage with a frame of CGRectMake(8, 8, 48, 48), you could use

let button: UIButton = UIButton(frame: CGRectMake(0, 0, 64, 64))
button.setImage(
    myImage,
    inFrame: CGRectMake(8, 8, 48, 48),
    forState: UIControlState.Normal
)

Copying a local file from Windows to a remote server using scp

Drive letter can be used in the source like

scp /c/path/to/file.txt user@server:/dir1/file.txt

How to compare 2 files fast using .NET?

This I have found works well comparing first the length without reading data and then comparing the read byte sequence

private static bool IsFileIdentical(string a, string b)
{            
   if (new FileInfo(a).Length != new FileInfo(b).Length) return false;
   return (File.ReadAllBytes(a).SequenceEqual(File.ReadAllBytes(b)));
}

Remove specific commit

So it sounds like the bad commit was incorporated in a merge commit at some point. Has your merge commit been pulled yet? If yes, then you'll want to use git revert; you'll have to grit your teeth and work through the conflicts. If no, then you could conceivably either rebase or revert, but you can do so before the merge commit, then redo the merge.

There's not much help we can give you for the first case, really. After trying the revert, and finding that the automatic one failed, you have to examine the conflicts and fix them appropriately. This is exactly the same process as fixing merge conflicts; you can use git status to see where the conflicts are, edit the unmerged files, find the conflicted hunks, figure out how to resolve them, add the conflicted files, and finally commit. If you use git commit by itself (no -m <message>), the message that pops up in your editor should be the template message created by git revert; you can add a note about how you fixed the conflicts, then save and quit to commit.

For the second case, fixing the problem before your merge, there are two subcases, depending on whether you've done more work since the merge. If you haven't, you can simply git reset --hard HEAD^ to knock off the merge, do the revert, then redo the merge. But I'm guessing you have. So, you'll end up doing something like this:

  • create a temporary branch just before the merge, and check it out
  • do the revert (or use git rebase -i <something before the bad commit> <temporary branch> to remove the bad commit)
  • redo the merge
  • rebase your subsequent work back on: git rebase --onto <temporary branch> <old merge commit> <real branch>
  • remove the temporary branch

CSS to set A4 paper size

CSS

body {
  background: rgb(204,204,204); 
}
page[size="A4"] {
  background: white;
  width: 21cm;
  height: 29.7cm;
  display: block;
  margin: 0 auto;
  margin-bottom: 0.5cm;
  box-shadow: 0 0 0.5cm rgba(0,0,0,0.5);
}
@media print {
  body, page[size="A4"] {
    margin: 0;
    box-shadow: 0;
  }
}

HTML

<page size="A4"></page>
<page size="A4"></page>
<page size="A4"></page>

DEMO

How to create Custom Ratings bar in Android

I need to add my solution which is WAY eaiser than the one above. We don't even need to use styles.

Create a selector file in the drawable folder:

custom_ratingbar_selector.xml

<?xml version="1.0" encoding="utf-8"?>
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
 <item android:id="@android:id/background"
    android:drawable="@drawable/star_off" />

 <item android:id="@android:id/secondaryProgress"
    android:drawable="@drawable/star_off" />

 <item android:id="@android:id/progress"
    android:drawable="@drawable/star_on" />

</layer-list>

In the layout set the selector file as progressDrawable:

 <RatingBar
        android:id="@+id/ratingBar2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="20dp"
        android:progressDrawable="@drawable/custom_ratingbar_selector"
        android:numStars="8"
        android:stepSize="0.2"
        android:rating="3.0" />

And that's all we need.

TSQL Default Minimum DateTime

Sometimes you inherit brittle code that is already expecting magic values in a lot of places. Everyone is correct, you should use NULL if possible. However, as a shortcut to make sure every reference to that value is the same, I like to put "constants" (for lack of a better name) in SQL in a scaler function and then call that function when I need the value. That way if I ever want to update them all to be something else, I can do so easily. Or if I want to change the default value moving forward, I only have one place to update it.

The following code creates the function and a table using it for the default DateTime value. Then inserts and select from the table without specifying the value for Modified. Then cleans up after itself. I hope this helps.

-- CREATE FUNCTION
CREATE FUNCTION dbo.DateTime_MinValue ( )
RETURNS DATETIME
AS 
    BEGIN
        DECLARE @dateTime_min DATETIME ;
        SET @dateTime_min = '1/1/1753 12:00:00 AM'
        RETURN @dateTime_min ;
    END ;
GO


-- CREATE TABLE USING FUNCTION FOR DEFAULT
CREATE TABLE TestTable
(
  TestTableId INT IDENTITY(1, 1)
                  PRIMARY KEY CLUSTERED ,
  Value VARCHAR(50) ,
  Modified DATETIME DEFAULT dbo.DateTime_MinValue()
) ;


-- INSERT VALUE INTO TABLE
INSERT  INTO TestTable
        ( Value )
VALUES  ( 'Value' ) ;


-- SELECT FROM TABLE
SELECT  TestTableId ,
        VALUE ,
        Modified
FROM    TestTable ;


-- CLEANUP YOUR DB
DROP TABLE TestTable ;
DROP FUNCTION dbo.DateTime_MinValue ;

How to assign an exec result to a sql variable?

declare @EventId int

CREATE TABLE #EventId (EventId int)

insert into #EventId exec rptInputEventId

set @EventId = (select * from #EventId)

drop table #EventId 

What is the right way to populate a DropDownList from a database?

public void getClientNameDropDowndata()
{
    getConnection = Connection.SetConnection(); // to connect with data base Configure manager
    string ClientName = "Select  ClientName from Client ";
    SqlCommand ClientNameCommand = new SqlCommand(ClientName, getConnection);
    ClientNameCommand.CommandType = CommandType.Text;
    SqlDataReader ClientNameData;
    ClientNameData = ClientNameCommand.ExecuteReader();
    if (ClientNameData.HasRows)
    {
        DropDownList_ClientName.DataSource = ClientNameData;
        DropDownList_ClientName.DataValueField = "ClientName";
        DropDownList_ClientName.DataTextField="ClientName";
        DropDownList_ClientName.DataBind();
    }
    else
    {
        MessageBox.Show("No is found");
        CloseConnection = new Connection();
        CloseConnection.closeConnection(); // close the connection 
    }
}

Global javascript variable inside document.ready

You can define the variable inside the document ready function without var to make it a global variable. In javascript any variable declared without var automatically becomes a global variable

$(document).ready(function() {
    intro =  "something";
});

although you cant use the variable immediately, but it would be accessible to other functions

Using scanner.nextLine()

I think your problem is that

int selection = scanner.nextInt();

reads just the number, not the end of line or anything after the number. When you declare

String sentence = scanner.nextLine();

This reads the remainder of the line with the number on it (with nothing after the number I suspect)

Try placing a scanner.nextLine(); after each nextInt() if you intend to ignore the rest of the line.

Clearing a string buffer/builder after loop

public void clear(StringBuilder s) {
    s.setLength(0);
}

Usage:

StringBuilder v = new StringBuilder();
clear(v);

for readability, I think this is the best solution.

C error: undefined reference to function, but it IS defined

Add the "extern" keyword to the function definitions in point.h

ToggleClass animate jQuery?

I attempted to use the toggleClass method to hide an item on my site (using visibility:hidden as opposed to display:none) with a slight animation, but for some reason the animation would not work (possibly due to an older version of jQuery UI).

The class was removed and added correctly, but the duration I added did not seem to make any difference - the item was simply added or removed with no effect.

So to resolve this I used a second class in my toggle method and applied a CSS transition instead:

The CSS:

.hidden{
    visibility:hidden;
    opacity: 0;
    -moz-transition: opacity 1s, visibility 1.3s;
    -webkit-transition: opacity 1s, visibility 1.3s;
    -o-transition: opacity 1s, visibility 1.3s;
    transition: opacity 1s, visibility 1.3s;
}
.shown{
    visibility:visible;
    opacity: 1;
    -moz-transition: opacity 1s, visibility 1.3s;
    -webkit-transition: opacity 1s, visibility 1.3s;
    -o-transition: opacity 1s, visibility 1.3s;
    transition: opacity 1s, visibility 1.3s;
}

The JS:

    function showOrHide() {
        $('#element').toggleClass("hidden shown");
    }

Thanks @tomas.satinsky for the awesome (and super simple) answer on this post.

How can I strip all punctuation from a string in JavaScript using regex?

/[^A-Za-z0-9\s]/g should match all punctuation but keep the spaces. So you can use .replace(/\s{2,}/g, " ") to replace extra spaces if you need to do so. You can test the regex in http://rubular.com/

.replace(/[^A-Za-z0-9\s]/g,"").replace(/\s{2,}/g, " ")

Update: Will only work if the input is ANSI English.

Full Page <iframe>

For full-screen frame redirects and similar things I have two methods. Both work fine on mobile and desktop.

Note this are complete cross-browser working, valid HTML files. Just change title and src for your needs.

1. this is my favorite:

<!DOCTYPE html>
<meta charset=utf-8>
<title> Title-1 </title>
<meta name=viewport content="width=device-width">
<style>
 html, body, iframe { height:100%; width:100%; margin:0; border:0; display:block }
</style>
<iframe src=src1></iframe>

<!-- More verbose CSS for better understanding:
  html   { height:100% }
  body   { height:100%; margin:0 }
  iframe { height:100%; width:100%; border:0; display:block }
-->

or 2. something like that, slightly shorter:

<!DOCTYPE html>
<meta charset=utf-8>
<title> Title-2 </title>
<meta name=viewport content="width=device-width">
<iframe src=src2 style="position:absolute; top:0; left:0; width:100%; height:100%; border:0">
</iframe>


Note:
The above examples avoid using height:100vh because old browsers don't know it (maybe moot these days) and height:100vh is not always equal to height:100% on mobile browsers (probably not applicable here). Otherwise, vh simplifies things a little bit, so

3. this is an example using vh (not my favorite, less compatible with little advantage)

<!DOCTYPE html>
<meta charset=utf-8>
<title> Title-3 </title>
<meta name=viewport content="width=device-width">
<style>
 body { margin:0 }
 iframe { display:block; width:100%; height:100vh; border:0 }
</style>
<iframe src=src3></iframe>

No authenticationScheme was specified, and there was no DefaultChallengeScheme found with default authentification and custom authorization

Your initial statement in the marked solution isn't entirely true. While your new solution may accomplish your original goal, it is still possible to circumvent the original error while preserving your AuthorizationHandler logic--provided you have basic authentication scheme handlers in place, even if they are functionally skeletons.

Speaking broadly, Authentication Handlers and schemes are meant to establish + validate identity, which makes them required for Authorization Handlers/policies to function--as they run on the supposition that an identity has already been established.

ASP.NET Dev Haok summarizes this best best here: "Authentication today isn't aware of authorization at all, it only cares about producing a ClaimsPrincipal per scheme. Authorization has to be aware of authentication somewhat, so AuthenticationSchemes in the policy is a mechanism for you to associate the policy with schemes used to build the effective claims principal for authorization (or it just uses the default httpContext.User for the request, which does rely on DefaultAuthenticateScheme)." https://github.com/aspnet/Security/issues/1469

In my case, the solution I'm working on provided its own implicit concept of identity, so we had no need for authentication schemes/handlers--just header tokens for authorization. So until our identity concepts changes, our header token authorization handlers that enforce the policies can be tied to 1-to-1 scheme skeletons.

Tags on endpoints:

[Authorize(AuthenticationSchemes = "AuthenticatedUserSchemeName", Policy = "AuthorizedUserPolicyName")]

Startup.cs:

        services.AddAuthentication(options =>
        {
            options.DefaultAuthenticateScheme = "AuthenticatedUserSchemeName";
        }).AddScheme<ValidTokenAuthenticationSchemeOptions, ValidTokenAuthenticationHandler>("AuthenticatedUserSchemeName", _ => { });

        services.AddAuthorization(options =>
        {
            options.AddPolicy("AuthorizedUserPolicyName", policy =>
            {
                //policy.RequireClaim(ClaimTypes.Sid,"authToken");
                policy.AddAuthenticationSchemes("AuthenticatedUserSchemeName");
                policy.AddRequirements(new ValidTokenAuthorizationRequirement());
            });
            services.AddSingleton<IAuthorizationHandler, ValidTokenAuthorizationHandler>();

Both the empty authentication handler and authorization handler are called (similar in setup to OP's respective posts) but the authorization handler still enforces our authorization policies.

Struct with template variables in C++

The Standard says (at 14/3. For the non-standard folks, the names following a class definition body (or the type in a declaration in general) are "declarators")

In a template-declaration, explicit specialization, or explicit instantiation the init-declarator-list in the dec-laration shall contain at most one declarator. When such a declaration is used to declare a class template, no declarator is permitted.

Do it like Andrey shows.

Best way to convert strings to symbols in hash

Here's a way to deep symbolize an object

def symbolize(obj)
    return obj.inject({}){|memo,(k,v)| memo[k.to_sym] =  symbolize(v); memo} if obj.is_a? Hash
    return obj.inject([]){|memo,v    | memo           << symbolize(v); memo} if obj.is_a? Array
    return obj
end

How to use Morgan logger?

var express = require('express');

var fs = require('fs');

var morgan = require('morgan')

var app = express();

// create a write stream (in append mode)
var accessLogStream = fs.createWriteStream(__dirname + '/access.log',{flags: 'a'});


// setup the logger
app.use(morgan('combined', {stream: accessLogStream}))


app.get('/', function (req, res) {
  res.send('hello, world!')
});

example nodejs + express + morgan

Center text in div?

You may try to use in your CSS the property vertical-align in order to center it verticaly

div {  
    vertical-align:middle;  
}

if it's a size problem, please notice that 2 text lines and a padding style have great chance to have a height superior to 30px.

For example, if your font size is 12 px and your div padding is 5 px, a one text line div height will be 5px (padding-top) + 12px + 5 px (padding-bottom) = 22px < 30px so no problem,

With a 2 text lines div, it will be 5px +12px *2 (2 lines) + 5px = 34px > 30px and your div height will be automatically changed.

Try either to increase your div height (maybe 40px) or to reduce your padding.

Hope it will help

Import text file as single character string

It seems your solution is not much ugly. You can use functions and make it proffesional like these ways

  • first way
new.function <- function(filename){
  readChar(filename, file.info(filename)$size)
}

new.function('foo.txt')
  • second way
new.function <- function(){
  filename <- 'foo.txt'
  return (readChar(filename, file.info(filename)$size))
}

new.function()

Using CSS how to change only the 2nd column of a table

You can use the :nth-child pseudo class like this:

.countTable table table td:nth-child(2)

Note though, this won't work in older browsers (or IE), you'll need to give the cells a class or use javascript in that case.

LINQ to Entities how to update a record

//for update

(from x in dataBase.Customers
         where x.Name == "Test"
         select x).ToList().ForEach(xx => xx.Name="New Name");

//for delete

dataBase.Customers.RemoveAll(x=>x.Name=="Name");

How do I login and authenticate to Postgresql after a fresh install?

There are two methods you can use. Both require creating a user and a database.

By default psql connects to the database with the same name as the user. So there is a convention to make that the "user's database". And there is no reason to break that convention if your user only needs one database. We'll be using mydatabase as the example database name.

  1. Using createuser and createdb, we can be explicit about the database name,

    $ sudo -u postgres createuser -s $USER
    $ createdb mydatabase
    $ psql -d mydatabase
    

    You should probably be omitting that entirely and letting all the commands default to the user's name instead.

    $ sudo -u postgres createuser -s $USER
    $ createdb
    $ psql
    
  2. Using the SQL administration commands, and connecting with a password over TCP

    $ sudo -u postgres psql postgres
    

    And, then in the psql shell

    CREATE ROLE myuser LOGIN PASSWORD 'mypass';
    CREATE DATABASE mydatabase WITH OWNER = myuser;
    

    Then you can login,

    $ psql -h localhost -d mydatabase -U myuser -p <port>
    

    If you don't know the port, you can always get it by running the following, as the postgres user,

    SHOW port;
    

    Or,

    $ grep "port =" /etc/postgresql/*/main/postgresql.conf
    

Sidenote: the postgres user

I suggest NOT modifying the postgres user.

  1. It's normally locked from the OS. No one is supposed to "log in" to the operating system as postgres. You're supposed to have root to get to authenticate as postgres.
  2. It's normally not password protected and delegates to the host operating system. This is a good thing. This normally means in order to log in as postgres which is the PostgreSQL equivalent of SQL Server's SA, you have to have write-access to the underlying data files. And, that means that you could normally wreck havoc anyway.
  3. By keeping this disabled, you remove the risk of a brute force attack through a named super-user. Concealing and obscuring the name of the superuser has advantages.

log4j:WARN No appenders could be found for logger in web.xml

If still help, verify the name of archive, it must be exact "log4j.properties" or "log4j.xml" (case sensitive), and follow the hint by "Alain O'Dea". I was geting the same error, but after make these changes everthing works fine. just like a charm :-). hope this helps.

Android Notification Sound

// set notification audio (Tested upto android 10)

builder.setDefaults(Notification.DEFAULT_VIBRATE);
//OR 
builder.setDefaults(Notification.DEFAULT_SOUND);

javascript, is there an isObject function like isArray?

You can use typeof operator.

if( (typeof A === "object" || typeof A === 'function') && (A !== null) )
{
    alert("A is object");
}

Note that because typeof new Number(1) === 'object' while typeof Number(1) === 'number'; the first syntax should be avoided.

Find the files that have been changed in last 24 hours

This command worked for me

find . -mtime -1 -print

Rails: How do I create a default value for attributes in Rails activerecord's model?

I found a better way to do it now:

def status=(value) 
  self[:status] = 'P' 
end 

In Ruby a method call is allowed to have no parentheses, therefore I should name the local variable into something else, otherwise Ruby will recognize it as a method call.

Receiving "fatal: Not a git repository" when attempting to remote add a Git repo

git was working fine for be and all of sudden it started showing this fatal: Not a git repository (or any of the parent directories): .git message.

For me not sure what was corrupted in .git folder, I did git clone ** newfolder and copied the entire .git folder to my corrupted/old folder where I was making changes before git started showing error message..

Everything got back to normal and git also recognized my changed/un-staged files.

rsync - mkstemp failed: Permission denied (13)

run in root access ssh chould solve this problem

or chmod 0777 /dir/to/be/backedup/

or chown username:user /dir/to/be/backedup/

paint() and repaint() in Java

The paint() method supports painting via a Graphics object.

The repaint() method is used to cause paint() to be invoked by the AWT painting thread.

#1214 - The used table type doesn't support FULLTEXT indexes

Only MyISAM allows for FULLTEXT, as seen here.

Try this:

CREATE TABLE gamemech_chat (
  id bigint(20) unsigned NOT NULL auto_increment,
  from_userid varchar(50) NOT NULL default '0',
  to_userid varchar(50) NOT NULL default '0',
  text text NOT NULL,
  systemtext text NOT NULL,
  timestamp datetime NOT NULL default '0000-00-00 00:00:00',
  chatroom bigint(20) NOT NULL default '0',
  PRIMARY KEY  (id),
  KEY from_userid (from_userid),
  FULLTEXT KEY from_userid_2 (from_userid),
  KEY chatroom (chatroom),
  KEY timestamp (timestamp)
) ENGINE=MyISAM;

Execute curl command within a Python script

You could use urllib as @roippi said:

import urllib2
data = '{"nw_src": "10.0.0.1/32", "nw_dst": "10.0.0.2/32", "nw_proto": "ICMP", "actions": "ALLOW", "priority": "10"}'
url = 'http://localhost:8080/firewall/rules/0000000000000001'
req = urllib2.Request(url, data, {'Content-Type': 'application/json'})
f = urllib2.urlopen(req)
for x in f:
    print(x)
f.close()

java.net.MalformedURLException: no protocol on URL based on a string modified with URLEncoder

You need to encode your parameter's values before concatenating them to URL.
Backslash \ is special character which have to be escaped as %5C

Escaping example:

String paramValue = "param\\with\\backslash";
String yourURLStr = "http://host.com?param=" + java.net.URLEncoder.encode(paramValue, "UTF-8");
java.net.URL url = new java.net.URL(yourURLStr);

The result is http://host.com?param=param%5Cwith%5Cbackslash which is properly formatted url string.

Automatically start a Windows Service on install

You can use the following command line to start the service:

net start *servicename*

ASP.NET MVC JsonResult Date Format

See this thread:

http://forums.asp.net/p/1038457/1441866.aspx#1441866

Basically, while the Date() format is valid javascript, it is NOT valid JSON (there is a difference). If you want the old format, you will probably have to create a facade and transform the value yourself, or find a way to get at the serializer for your type in the JsonResult and have it use a custom format for dates.

Find the paths between two given nodes?

Dijkstra's algorithm applies more to weighted paths and it sounds like the poster was wanting to find all paths, not just the shortest.

For this application, I'd build a graph (your application sounds like it wouldn't need to be directed) and use your favorite search method. It sounds like you want all paths, not just a guess at the shortest one, so use a simple recursive algorithm of your choice.

The only problem with this is if the graph can be cyclic.

With the connections:

  • 1, 2
  • 1, 3
  • 2, 3
  • 2, 4

While looking for a path from 1->4, you could have a cycle of 1 -> 2 -> 3 -> 1.

In that case, then I'd keep a stack as traversing the nodes. Here's a list with the steps for that graph and the resulting stack (sorry for the formatting - no table option):

current node (possible next nodes minus where we came from) [stack]

  1. 1 (2, 3) [1]
  2. 2 (3, 4) [1, 2]
  3. 3 (1) [1, 2, 3]
  4. 1 (2, 3) [1, 2, 3, 1] //error - duplicate number on the stack - cycle detected
  5. 3 () [1, 2, 3] // back-stepped to node three and popped 1 off the stack. No more nodes to explore from here
  6. 2 (4) [1, 2] // back-stepped to node 2 and popped 1 off the stack.
  7. 4 () [1, 2, 4] // Target node found - record stack for a path. No more nodes to explore from here
  8. 2 () [1, 2] //back-stepped to node 2 and popped 4 off the stack. No more nodes to explore from here
  9. 1 (3) [1] //back-stepped to node 1 and popped 2 off the stack.
  10. 3 (2) [1, 3]
  11. 2 (1, 4) [1, 3, 2]
  12. 1 (2, 3) [1, 3, 2, 1] //error - duplicate number on the stack - cycle detected
  13. 2 (4) [1, 3, 2] //back-stepped to node 2 and popped 1 off the stack
  14. 4 () [1, 3, 2, 4] Target node found - record stack for a path. No more nodes to explore from here
  15. 2 () [1, 3, 2] //back-stepped to node 2 and popped 4 off the stack. No more nodes
  16. 3 () [1, 3] // back-stepped to node 3 and popped 2 off the stack. No more nodes
  17. 1 () [1] // back-stepped to node 1 and popped 3 off the stack. No more nodes
  18. Done with 2 recorded paths of [1, 2, 4] and [1, 3, 2, 4]

What is a NoReverseMatch error, and how do I fix it?

The NoReverseMatch error is saying that Django cannot find a matching url pattern for the url you've provided in any of your installed app's urls.

The NoReverseMatch exception is raised by django.core.urlresolvers when a matching URL in your URLconf cannot be identified based on the parameters supplied.

To start debugging it, you need to start by disecting the error message given to you.

  • NoReverseMatch at /my_url/

    This is the url that is currently being rendered, it is this url that your application is currently trying to access but it contains a url that cannot be matched

  • Reverse for 'my_url_name'

    This is the name of the url that it cannot find

  • with arguments '()' and

    These are the non-keyword arguments its providing to the url

  • keyword arguments '{}' not found.

    These are the keyword arguments its providing to the url

  • n pattern(s) tried: []

    These are the patterns that it was able to find in your urls.py files that it tried to match against

Start by locating the code in your source relevant to the url that is currently being rendered - the url, the view, and any templates involved. In most cases, this will be the part of the code you're currently developing.

Once you've done this, read through the code in the order that django would be following until you reach the line of code that is trying to construct a url for your my_url_name. Again, this is probably in a place you've recently changed.

Now that you've discovered where the error is occuring, use the other parts of the error message to work out the issue.

The url name

  • Are there any typos?
  • Have you provided the url you're trying to access the given name?
  • If you have set app_name in the app's urls.py (e.g. app_name = 'my_app') or if you included the app with a namespace (e.g. include('myapp.urls', namespace='myapp'), then you need to include the namespace when reversing, e.g. {% url 'myapp:my_url_name' %} or reverse('myapp:my_url_name').

Arguments and Keyword Arguments

The arguments and keyword arguments are used to match against any capture groups that are present within the given url which can be identified by the surrounding () brackets in the url pattern.

Assuming the url you're matching requires additional arguments, take a look in the error message and first take a look if the value for the given arguments look to be correct.

If they aren't correct:

  • The value is missing or an empty string

    This generally means that the value you're passing in doesn't contain the value you expect it to be. Take a look where you assign the value for it, set breakpoints, and you'll need to figure out why this value doesn't get passed through correctly.

  • The keyword argument has a typo

    Correct this either in the url pattern, or in the url you're constructing.

If they are correct:

  • Debug the regex

    You can use a website such as regexr to quickly test whether your pattern matches the url you think you're creating, Copy the url pattern into the regex field at the top, and then use the text area to include any urls that you think it should match against.

    Common Mistakes:

    • Matching against the . wild card character or any other regex characters

      Remember to escape the specific characters with a \ prefix

    • Only matching against lower/upper case characters

      Try using either a-Z or \w instead of a-z or A-Z

  • Check that pattern you're matching is included within the patterns tried

    If it isn't here then its possible that you have forgotten to include your app within the INSTALLED_APPS setting (or the ordering of the apps within INSTALLED_APPS may need looking at)

Django Version

In Django 1.10, the ability to reverse a url by its python path was removed. The named path should be used instead.


If you're still unable to track down the problem, then feel free to ask a new question that includes what you've tried, what you've researched (You can link to this question), and then include the relevant code to the issue - the url that you're matching, any relevant url patterns, the part of the error message that shows what django tried to match, and possibly the INSTALLED_APPS setting if applicable.

Alphanumeric, dash and underscore but no spaces regular expression check JavaScript

However, the code below allows spaces.

No, it doesn't. However, it will only match on input with a length of 1. For inputs with a length greater than or equal to 1, you need a + following the character class:

var regexp = /^[a-zA-Z0-9-_]+$/;
var check = "checkme";
if (check.search(regexp) === -1)
    { alert('invalid'); }
else
    { alert('valid'); }

Note that neither the - (in this instance) nor the _ need escaping.

Installing PDO driver on MySQL Linux server

  1. PDO stands for PHP Data Object.
  2. PDO_MYSQL is the driver that will implement the interface between the dataobject(database) and the user input (a layer under the user interface called "code behind") accessing your data object, the MySQL database.

The purpose of using this is to implement an additional layer of security between the user interface and the database. By using this layer, data can be normalized before being inserted into your data structure. (Capitals are Capitals, no leading or trailing spaces, all dates at properly formed.)

But there are a few nuances to this which you might not be aware of.

First of all, up until now, you've probably written all your queries in something similar to the URL, and you pass the parameters using the URL itself. Using the PDO, all of this is done under the user interface level. User interface hands off the ball to the PDO which carries it down field and plants it into the database for a 7-point TOUCHDOWN.. he gets seven points, because he got it there and did so much more securely than passing information through the URL.

You can also harden your site to SQL injection by using a data-layer. By using this intermediary layer that is the ONLY 'player' who talks to the database itself, I'm sure you can see how this could be much more secure. Interface to datalayer to database, datalayer to database to datalayer to interface.

And:

By implementing best practices while writing your code you will be much happier with the outcome.

Additional sources:

Re: MySQL Functions in the url php dot net/manual/en/ref dot pdo-mysql dot php

Re: three-tier architecture - adding security to your applications https://blog.42.nl/articles/introducing-a-security-layer-in-your-application-architecture/

Re: Object Oriented Design using UML If you really want to learn more about this, this is the best book on the market, Grady Booch was the father of UML http://dl.acm.org/citation.cfm?id=291167&CFID=241218549&CFTOKEN=82813028

Or check with bitmonkey. There's a group there I'm sure you could learn a lot with.

>

If we knew what the terminology really meant we wouldn't need to learn anything.

>

Convert command line argument to string

You can create an std::string

#include <string>
#include <vector>
int main(int argc, char *argv[])
{
  // check if there is more than one argument and use the second one
  //  (the first argument is the executable)
  if (argc > 1)
  {
    std::string arg1(argv[1]);
    // do stuff with arg1
  }

  // Or, copy all arguments into a container of strings
  std::vector<std::string> allArgs(argv, argv + argc);
}

Converting dictionary to JSON

json.dumps() is used to decode JSON data

  • json.loads take a string as input and returns a dictionary as output.
  • json.dumps take a dictionary as input and returns a string as output.
import json

# initialize different data
str_data = 'normal string'
int_data = 1
float_data = 1.50
list_data = [str_data, int_data, float_data]
nested_list = [int_data, float_data, list_data]
dictionary = {
    'int': int_data,
    'str': str_data,
    'float': float_data,
    'list': list_data,
    'nested list': nested_list
}

# convert them to JSON data and then print it
print('String :', json.dumps(str_data))
print('Integer :', json.dumps(int_data))
print('Float :', json.dumps(float_data))
print('List :', json.dumps(list_data))
print('Nested List :', json.dumps(nested_list, indent=4))
print('Dictionary :', json.dumps(dictionary, indent=4))  # the json data will be indented

output:

String : "normal string"
Integer : 1
Float : 1.5
List : ["normal string", 1, 1.5]
Nested List : [
    1,
    1.5,
    [
        "normal string",
        1,
        1.5
    ]
]
Dictionary : {
    "int": 1,
    "str": "normal string",
    "float": 1.5,
    "list": [
        "normal string",
        1,
        1.5
    ],
    "nested list": [
        1,
        1.5,
        [
            "normal string",
            1,
            1.5
        ]
    ]
}
  • Python Object to JSON Data Conversion
|                 Python                 |  JSON  |
|:--------------------------------------:|:------:|
|                  dict                  | object |
|               list, tuple              |  array |
|                   str                  | string |
| int, float, int- & float-derived Enums | number |
|                  True                  |  true  |
|                  False                 |  false |
|                  None                  |  null  |

Programmatically saving image to Django ImageField

Another possible way to do that:

from django.core.files import File

with open('path_to_file', 'r') as f:   # use 'rb' mode for python3
    data = File(f)
    model.image.save('filename', data, True)

Force a screen update in Excel VBA

Text boxes in worksheets are sometimes not updated when their text or formatting is changed, and even the DoEvent command does not help.

As there is no command in Excel to refresh a worksheet in the way a user form can be refreshed, it is necessary to use a trick to force Excel to update the screen.

The following commands seem to do the trick:

- ActiveSheet.Calculate    
- ActiveWindow.SmallScroll    
- Application.WindowState = Application.WindowState