Build theme from scratch

ESNext for JavaScript

Sass

OOP

Singleton

PHP Classes

Namespace

Registering Custom Menus

Editing the Default WordPress Menus

Registering CPTs, Taxonomy

Infinite Scroll

Pagination

Custom page templates

Writing WP Queries

Blog Page

Archive

Post Filters with load more

Creating customizer options

Working with user admin roles

Creating Theme option page

Using slick slider.

Creating Custom Widgets

Adding comment form

Adding related posts

Translation

Making ajax request

Using WordPress REST API

PHP Namespace

• A way of encapsulating items
• Like a virtual folder or directory defined with namespace keyword at the top of the class file following by the name you like.
• Allow you to have two or more classes with the same name in different namespaced directories.

class Product{} //define
$product = new Product(); //use

namespace App
class Product{}

$product = new App\Product();
or use App;

Autoloaders

spl_autoload_register()

spl_autoload_register( function( $class ) {
    include 'includes/' . $class . '.php'
} );

new Student()
new Person()

• Loading classes or interfaces automatically
• Registers any no. of autoloaders
• Enables classes and interfaces to be automatically loaded if they are currently not defined

Traits

• Earlier we could only inherit properties and Functions from one class to another, by extending them.
• if we want the properties/methods of inherited class or into another, we need to extend it again creates chain of inheritance.
• PHP( 5.4+ ) introduced a mechanism for code reusability called traits.

Teacher() ---> Person()
teach()   extend

Student() ------> Person()
learn()    trait
Student2() ------> Person()
           trait
Student3() ------> Person()
           trait

• Traits allow us to reuse sets of methods freely in several independent classes living in different class hierarchies.
• Share functionalities from multiple classes
• A trait is similar to a class, but only intended to group functioning in a fine-grained and consistent way.

trait Say_World {
    public function say_hello() {
        echo "Hello Trait";
    }
}

trait TimeTracker() {
    public function say_time() {
        echo "Current time is 2.00PM";
    }
}

class Teacher{
    public function say_name() {
        echo 'Teacher';
    }
}
class Base extends Teacher {
    use Say_World, TimeTracker;
    public function_construct() {
        //
    }
}

$base = new Base();
$base->say_hello();
$base->say_name();

Singleton

<?php
// Singleton create only one instance object 
class Signleton{

    private static $instance = null;

    private function __construct() {
        //
    }

    public static function get_instance() {
        if( static::$instance === null ) {
            static::$instance = new static();
        }
        return static::$instance;
    }

    private function __clone(){
        //
    }

    private function __wakeup() {
        //
    }
}

// create object
$object = Singleton::get_instance();
$anotherObj = Singleton::get_instance();
var_dump( $object == $anotherObj );
?>

Singleton and Traits

<?php
trait Signleton{

    private static $instances = [];

    private final function __construct() {
        //
    }

    public static function get_instance() {
        static $instances = [];
        $called_class = get_called_class();

        if( ! isset( $instances[ $called_class ] ) ) {
            $instances[ $called_class ] = new $called_class;
        }
        return $instances[ $called_class ];
    }

    private final function __clone(){
        //
    }

    private final function __wakeup() {
        //
    }
}

//User
include_once('Singleton.php');
class User{
    use Singleton;
    public function construct() {
        echo 'User';
    }
}
$user_one = User::get_instance();

//Person
include_once('Singleton.php');
class Person{
    use Singleton;
    public function construct() {
        echo 'Person';
    }
}
$person_one = Person::get_instance();