Tutorial by Examples: in

Rolling Back Migrations

What if you want to rollback the latest migration i.e recent operation, you can use the awesome rollback command. But remember that this command rolls back only the last migration, which may include multiple migration files php artisan migrate:rollback If you are interested in rolling back all o...

Laravel • Database Migrations

Break and continue labels

Break and continue statements can be followed by an optional label which works like some kind of a goto statement, resumes execution from the label referenced position for(var i = 0; i < 5; i++){ nextLoop2Iteration: for(var j = 0; j < 5; j++){ if(i == j) break nextLoop2Iteration; ...

JavaScript • Loops

Measuring time - console.time()

console.time() can be used to measure how long a task in your code takes to run. Calling console.time([label]) starts a new timer. When console.timeEnd([label]) is called, the elapsed time, in milliseconds, since the original .time() call is calculated and logged. Because of this behavior, you can ...

JavaScript • Console

Installation or Setup

Log into your AWS Console and click on Lambda under the Services tab. Under Functions you'll be able to Create a Lambda function using the same-labeled button. You'll be shown a screen where you can select a blueprint. These are simply starting points to existing Lambda functions fo...

aws-lambda • Getting started with aws-lambda

Looping with async await

When using async await in loops, you might encounter some of these problems. If you just try to use await inside forEach, this will throw an Unexpected token error. (async() => { data = [1, 2, 3, 4, 5]; data.forEach(e => { const i = await somePromiseFn(e); console.log(i); }); ...

JavaScript • Async functions (async/await)

Creating Collections

Using the collect() helper, you can easily create new collection instances by passing in an array such as: $fruits = collect(['oranges', 'peaches', 'pears']); If you don't want to use helper functions, you can create a new Collection using the class directly: $fruits = new Illuminate\Support\Co...

Laravel • Collections

Bind Once

Angular has reputation for having awesome bidirectional data binding. By default, Angular continuously synchronizes values bound between model and view components any time data changes in either the model or view component. This comes with a cost of being a bit slow if used too much. This will hav...

AngularJS • Profiling and Performance

Pagination in Laravel

In other frameworks pagination is headache. Laravel makes it breeze, it can generate pagination by adding few lines of code in Controller and View. Basic Usage There are many ways to paginate items, but the simplest one is using the paginate method on query builder or an Eloquent query. Laravel ou...

Laravel • Pagination

Installation or Setup

Using a CDN: <!DOCTYPE html> <head> <script src="https://cdn.jsdelivr.net/rxjs/4.1.0/rx.min.js"></script> </head> <body> <script> // `Rx` is available var one$ = Rx.Observable.of(1); var onesub = one$.subscribe(function (...

rxjs • Getting started with rxjs

Supporting Multiple Domains

Each domain supported in the app needs to make available its own apple-app-site-association file. If the content served by each domain is different, then the contents of the file will also change to support the respective paths. Otherwise, the same file can be used, but it needs to be accessible at ...

iOS • Universal Links

Signing the App-Site-Association File

Note: You can skip this part if your server uses HTTPS to serve content and jump to Application Setup guide. If your app targets iOS 9 and your server uses HTTPS to serve content, you don’t need to sign the file. If not (e.g. when supporting Handoff on iOS 8), it has to be signed using a SSL certif...

iOS • Universal Links

Setup iOS Application (Enabling Universal Links)

The setup on the app side requires two things: Configuring the app’s entitlement, and enabling the universal links by turning on the Associated Domains capability in the project. Handling Incoming Links in your AppDelegate. 1. Configuring the app’s entitlement, and enabling universal links. ...

iOS • Universal Links

Default logging

Mage::log('My log entry'); Mage::log('My log message: '.$myVariable); Mage::log($myArray); Mage::log($myObject); This will log to /var/log/system.log Objects and Arrays are automatically written via a print_r() directive. Watch out when using objects since these can get substantial in size. ...

magento • Logging to file

Installation or Setup

Detailed instructions on getting facebook-graph-api set up or installed.

facebook-graph-api • Getting started with facebook-graph-api

Common Pitfalls: Accessing DOM from the `ready()` hook

A common usecase for the ready() hook is to access the DOM, e.g. to initiate a Javascript plugin, get the dimensions of an element etc. The problem Due to Vue's asynchronous DOM update mechanism, it's not guaranteed that the DOM has been fully updated when the ready() hook is called. This usually ...

Vue.js • Lifecycle Hooks

include & require

require require is similar to include, except that it will produce a fatal E_COMPILE_ERROR level error on failure. When the require fails, it will halt the script. When the include fails, it will not halt the script and only emit E_WARNING. require 'file.php'; PHP Manual - Control Structures - ...

PHP • Control Structures

Synthesising audio

In this example we show how to generate a simple sine wave, and output it on the user's speakers/headphones. let audioContext = new (window.AudioContext || window.webkitAudioContext)(); let sourceNode = audioContext.createOscillator(); sourceNode.type = 'sine'; sourceNode.frequency.value = 261...

web-audio • Getting started with web-audio

Using effects on audio

Effects can be applied to audio by chaining nodes between the source and the destination node. In this example we use a gain node to mute the source, and only let sound through at specific times. This allows us to create morse code. function morse(gainNode, pattern) { let silenceTimeout = 300; ...

web-audio • Getting started with web-audio

Checking, setting, clearing, and toggling individual bits. Using long as bit mask

Assuming we want to modify bit n of an integer primitive, i (byte, short, char, int, or long): (i & 1 << n) != 0 // checks bit 'n' i |= 1 << n; // sets bit 'n' to 1 i &= ~(1 << n); // sets bit 'n' to 0 i ^= 1 << n; // toggles the value of bit 'n' Us...

Java Language • Bit Manipulation

Overloading on Forwarding Reference

You must be very careful when providing a forwarding reference overload as it may match too well: struct A { A() = default; // #1 A(A const& ) = default; // #2 template <class T> A(T&& ); // #3 }; The intent here was that A is c...

C++ • Overload resolution