Tutorial by Examples: e

Custom text replace binding

This example is a custom binding that replaces text whenever an input value is updated. In this case, spaces will be replaced with "+". It is intended to be used alongside the existing value binding, and shows binding with an object literal. Sample markup with the replaceText binding: &l...

knockout.js • Custom Bindings

Open camara and photo gallery

index.html <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta http-equiv="Content-Security-Policy" content="default-src *; script-src 'self' 'unsafe-inline' 'unsafe-eval' *; style-src 'self' 'unsafe-inline' *"/> ...

ionic-framework • Device camera and photo library access from Ionic application

Installation or Setup

Detailed instructions on getting opencart set up or installed.

opencart • Getting started with opencart

Celery Configuration

CELERY Installation - pip install django-celery Add Basic project structure. - src/ - bin/celery_worker_start # will be explained later on - logs/celery_worker.log - stack/__init __.py - stack/celery.py - stack/settings.py - stack/urls.py - manage.py ...

Django • Running Celery with Supervisor

Running Supervisor

Create a script to start celery worker. Insert your script within your app. For example: stack/bin/celery_worker_start #!/bin/bash NAME="StackOverflow Project - celery_worker_start" PROJECT_DIR=/home/stackoverflow/apps/proj/proj/ ENV_DIR=/home/stackoverflow/apps/proj/env/...

Django • Running Celery with Supervisor

Display the source code of an object

Objects that are not built-in To print the source code of a Python object use inspect. Note that this won't work for built-in objects nor for objects defined interactively. For these you will need other methods explained later. Here's how to print the source code of the method randint from the ran...

Python Language • Accessing Python source code and bytecode

Null Object Java using enum

Given an interface: public interface Logger { void log(String message); } Rather than usage: public void doJob(Logger logger) { if (logger != null) { logger.log("[doJob]:Step 1"); } // ... if (logger != null) { logger.log("[doJob]:Step 2&q...

Design patterns • Null Object pattern

Named operators

You can extend C++ with named operators that are "quoted" by standard C++ operators. First we start with a dozen-line library: namespace named_operator { template<class D>struct make_operator{constexpr make_operator(){}}; template<class T, char, class O> struct half_a...

C++ • Operator Overloading

Pre/Post Increment/Decrement operators

In C, there are two unary operators - '++' and '--' that are very common source of confusion. The operator ++ is called the increment operator and the operator -- is called the decrement operator. Both of them can be used used in either prefix form or postfix form. The syntax for prefix form for ++ ...

C Language • Side Effects

Encryption by certificate

CREATE CERTIFICATE My_New_Cert FROM FILE = 'D:\Temp\CertTest\certificateDER.cer' GO Create the certificate SELECT EncryptByCert(Cert_ID('My_New_Cert'), 'This text will get encrypted') encryption_test Usually, you would encrypt with a symmetric key, that key would get encrypted by the asym...

Microsoft SQL Server • Encryption

Encryption of database

USE TDE CREATE DATABASE ENCRYPTION KEY WITH ALGORITHM = AES_256 ENCRYPTION BY SERVER CERTIFICATE My_New_Cert GO ALTER DATABASE TDE SET ENCRYPTION ON GO This uses 'Transparent Data Encryption' (TDE)

Microsoft SQL Server • Encryption

Encryption by symmetric key

-- Create the key and protect it with the cert CREATE SYMMETRIC KEY My_Sym_Key WITH ALGORITHM = AES_256 ENCRYPTION BY CERTIFICATE My_New_Cert; GO -- open the key OPEN SYMMETRIC KEY My_Sym_Key DECRYPTION BY CERTIFICATE My_New_Cert; -- Encrypt SELECT EncryptByKey(Key_GUID('SSN_Key_01'),...

Microsoft SQL Server • Encryption

Intro to Queue

The queue is a FIFO (first-in, first-out) data-structure, i.e. the first element added to the queue will be the first element removed ("first out"). Let us consider the example of customers waiting to be helped. Alice, Bob, and Dan are all at the supermarket. Alice is ready to pay, so she...

data-structures • Queue

System.Runtime.Caching.MemoryCache (ObjectCache)

This function gets existing item form cache, and if the item don't exist in cache, it will fetch item based on the valueFetchFactory function. public static TValue GetExistingOrAdd<TValue>(string key, double minutesForExpiration, Func<TValue> valueFetchFactory) { ...

.NET Framework • System.Runtime.Caching.MemoryCache (ObjectCache)

Write your own generator-backed iterator

A common pattern in other languages is having a function that produces a "stream" of objects, and being able to use loop-code to loop over it. We can model this in C++ as template<class T> struct generator_iterator { using difference_type=std::ptrdiff_t; using value_type=T; ...

C++ • Iterators

Sensible defaults

SASS gives you the ability to omit any parameter except the ones you want to overwrite of course. Let's take again the default-box example: @mixin default-box ($color: red, $borderColor: blue) { color: $color; border: 1px solid $borderColor; clear: both; display: block; mar...

sass • Mixins

Explicit Binding

To register an explicit binding, use the router's model method to specify the class for a given parameter. You should define your explicit model bindings in the boot method of the RouteServiceProvider class public function boot() { parent::boot(); Route::model('user', App\User::class); ...

Laravel • Route Model Binding

Factory VS Service once-and-for-all

By definition: Services are basically constructor functions. They use ‘this’ keyword. Factories are simple functions hence return an object. Under the hood: Factories internally calls provider function. Services internally calls Factory function. Debate: Factories can run code before we retur...

AngularJS • Distinguishing Service vs Factory

Versions

Latest Cordova version: Cordova 6.1.0 - https://cordova.apache.org/news/2016/03/23/tools-release.html Cordova 6.0.0 - https://cordova.apache.org/news/2016/01/28/tools-release.html Latest Android platform and iOS plaatform Cordova Android 5.2.2 - https://cordova.apache.org/announcements/2...

Cordova • Getting started with Cordova

Finding "out-of-sequence" records using the LAG() function

Given these sample data: IDSTATUSSTATUS_TIMESTATUS_BY1ONE2016-09-28-19.47.52.501398USER_13ONE2016-09-28-19.47.52.501511USER_21THREE2016-09-28-19.47.52.501517USER_33TWO2016-09-28-19.47.52.501521USER_23THREE2016-09-28-19.47.52.501524USER_4 Items identified by ID values must move from STATUS 'ONE' to...

SQL • Window Functions