php类中的WordPress主题激活挂钩

Question

I want to run a function when my theme is activated. I have to add the theme activation hook within a php class:

final class My_Class_Name {

    public static function getInstance() {
        if (self::$instance == null) {
            self::$instance = new self;               
            self::$instance->actions();
        } else {
            throw new BadFunctionCallException(sprintf('Plugin %s already instantiated', __CLASS__));
        }
        return self::$instance;
    }


   // some code

   add_action('after_switch_theme', array( $this, 'activate' ));

   function activate() {
      // some code
   }

   // more code

}

My_Class_Name::getInstance();

When I activate my theme I get the following php error:

PHP Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'My_Class_Name' does not have a method 'activate' in /Applications/MAMP/htdocs/wp-themes/test/wp-includes/class-wp-hook.php on line 288

If I use add_action('after_switch_theme', 'activate' );

I get

PHP Fatal error: Cannot access self:: when no class scope is active

How can I make the hook work?

Answer 1

Here a simple way i made it work.

final class My_Class_Name {

    // some code

    public function __construct(){
        add_action('after_switch_theme', array( $this, 'activate' ));
    }

    public function activate() {
        file_put_contents(__DIR__.'\de.log','TEST');
    }

    // more code

}

new My_Class_Name();

Here is another way you can instantiate.

class My_Class_Name{

    protected static $instance = null;

    public function __construct(){}

    public static function get_instance() {
        // If the single instance hasn't been set, set it now.
        if ( null == self::$instance ) {
            self::$instance = new self;
        }

        return self::$instance;
    }
}

My_Class_Name::get_instance();