Creating a custom template loader

First, we have to add a function to the WP_Theme class of the plugin to include the template loader file, as shown in the following code. Also, we have to update the constructor to call the template_init function upon plugin initialization:

public function template_init() {
    include_once 'class-wpwa-template-loader.php';
}

Create a new file named class-wpwa-template-loader.php inside the plugin class to implement the template loader. Let's implement the loader by creating a new class named WPWA_Template_Loader inside the class-wpwa-template-loader.php file:

class WPWA_Template_Loader{
    private $template_dir;
    public function __construct(){
   	 	$this->template_dir = "templates";
    }
    public function render($name,$data =  array() ){
   	   include plugin_dir_path(__FILE__).$this->template_dir."/".$name.".php";
    }
}

The folder named templates will be used to create all the templates required for the theme. Then, we will add a function named...