Tutorial by Examples: in

Iterating over nodes

The NodeIterator interface provides methods for iterating over nodes in a DOM tree. Given a document like this one: <html> <body> <section class="main"> <ul> <li>List Item</li> <li>List Item</li> <li>Li...

DOM • Traversal

Removing a class

Modern browsers provide a classList object to ease manipulation of the element's class attribute. Older browsers require direct manipulation of the element's className property. * Note class names are not stored in the element's property in any particular order W3C DOM4 Removing one class from an...

DOM • Manipulating a list of CSS classes

Testing for a class

Modern browsers provide a classList object to ease manipulation of the element's class attribute. Older browsers require direct manipulation of the element's className property. * Note class names are not stored in the element's property in any particular order W3C DOM4 Testing if an element cont...

DOM • Manipulating a list of CSS classes

Working with columns containg NULL values

In MySQL and other SQL dialects, NULL values have special properties. Consider the following table containing job applicants, the companies they worked for, and the date they left the company. NULL indicates that an applicant still works at the company: CREATE TABLE example (`applicant_id` INT, `...

MySQL • Dealing with sparse or missing data

Optimizing Storage Layout for InnoDB Tables

In InnoDB, having a long PRIMARY KEY (either a single column with a lengthy value, or several columns that form a long composite value) wastes a lot of disk space. The primary key value for a row is duplicated in all the secondary index records that point to the same row. Create an AUTO_INCREME...

MySQL • Mysql Performance Tips

Safe reseeding

You may want to re-seed your database without affecting your previously created seeds. For this purpose, you can use firstOrCreate in your seeder: EmployeeType::firstOrCreate([ 'type' => 'manager', ]); Then you can seed the database: php artisan db:seed Later, if you want to add a...

Laravel • Seeding

Installing Ruby with RVM

The Ruby Version Manager is a command line tool to simply install and manage different versions of Ruby. rvm istall 2.3.1 for example installs Ruby version 2.3.1 on your machine. With rvm list you can see which versions are installed and which is actually set for use. user@dev:~$ rvm li...

Ruby Language • Ruby Version Manager

Adding Siri Extension to App

To integrate Siri capabilities in your app, you should add an extensions as you would do while creating an iOS 10 Widget (old Today View Extension) or a custom keyboard. Adding capability 1- In the project settings, select your iOS app target and go to Capabilities tab 2- Enable the Siri capabili...

iOS • SiriKit

Create an empty dataset based on an existing dataset

Method 1: proc sql; create table foo like sashelp.class; quit; Method 2: proc sql; create table bar as select * from sashelp.class (obs=0); quit; Method 1 should be the preferred option

sas • Proc SQL

Authorizing Contact Access

Importing the framework Swift import Contacts Objective-C #import <Contacts/Contacts.h> Checking accessibility Swift switch CNContactStore.authorizationStatusForEntityType(CNEntityType.Contacts){ case .Authorized: //access contacts case .Denied, .NotDetermined: //request permissio...

iOS • Contacts Framework

Accessing Contacts

Applying a filter To access contacts, we should apply a filter of type NSPredicate to our contactStore variable which we defined it in Authorizing Contact Access example. For example, here we want to sort out contacts with name matching with our own: Swift let predicate = CNContact.predicateForCo...

iOS • Contacts Framework

Jenkins 2.0+ Pipeline Script

Modern versions of Jenkins (version 2.x) come with a "Build Pipeline Plugin" that can be used to orchestrate complex CI tasks without creating a multitude of interconnected jobs, and allow you to easily version-control your build / test configuration. You may install this manually in a &q...

Django • Continuous Integration With Jenkins

Jenkins 2.0+ Pipeline Script, Docker Containers

Here is an example of a pipeline script that builds a Docker container, then runs the tests inside of it. The entrypoint is assumed to be either manage.py or invoke/fabric with a runtests command available. #!/usr/bin/groovy node { stage 'Checkout' checkout scm sh 'git submodule update ...

Django • Continuous Integration With Jenkins

Initialization

The push notification plugin requires an init an initialization which tells the plugin to start running using the sender id provided. let push = Push.init({ android: { senderID: "------------", }, ios: { alert: "true", badge: tru...

ionic2 • Push notification sent & receive

Receiving a push notification

To receive push notifications we are supposed to tell the plugin to listen to incoming push notifications. This step is done after initialization & registration import { Push, NotificationEventResponse} from "ionic-native"; //the push element is created in the initial...

ionic2 • Push notification sent & receive

Detect basic informations about your distro

just execute uname -a. On Arch: $ uname -a Linux nokia 4.6.4-1-ARCH #1 SMP PREEMPT Mon Jul 11 19:12:32 CEST 2016 x86_64 GNU/Linuxenter code here

GNU/Linux • Detecting Linux distribution name and version

Testing a Java class with JUnit and the Maven Surefire plugin

The Maven Surefire plugin runs during the test phase of the Maven build process or when test is specified as a Maven goal. The following directory structure and minimum pom.xml file will configure Maven to run a test. Directory structure inside the project's root directory: ─ project_root ├─ p...

Apache Maven • Maven Surefire Plugin

find your linux os (both debian & rpm) name and release number

Most of linux distros stores its version info in the /etc/lsb-release (debian) or /etc/redhat-release (RPM based) file. Using below generic command should get you past most of the Debian and RPM derivatives as Linux Mint and Cent-Os. Example on Ubuntu Machine: cat /etc/*release DISTRIB_ID=Ubuntu ...

GNU/Linux • Detecting Linux distribution name and version

Understanding stand-alone media files

The sample content used here is Tears of Steel, by Blender Foundation. Specifically, we will use the download titled "HD 720p (~365MB, mov, 2.0)". This is a single file that ends with the extension "mov" and will play in just about any modern media player. Note that the download...

video • Understanding a media presentation

Understanding components of video tracks

This example will explore how to see the layout of a video track and how to extract the individual pictures within it. The sample content used here is Tears of Steel, by Blender Foundation. Specifically, we will use the download titled "HD 720p (~365MB, mov, 2.0)". This is a single file t...

video • Understanding a media presentation