How to remove_action inside class [duplicate]

Question

i have class like this

if ( ! class_exists( 'My_class' ) ) {
    class My_class {
        public function __construct() {
            add_action( 'woocommerce_shop_loop_item_title', array( $this, 'change_title' ), 10 );
        }

        public function change_title() {
            echo 'The title';
        }
    }
}

return new My_class();

I trying to remove_action change_title by using

remove_action( 'woocommerce_before_shop_loop_item_title', array( 'My_class', 'change_title' ), 10 );
// or
remove_action( 'woocommerce_before_shop_loop_item_title', 10 );

But it does not work because I don't really understand PHP OOP. How can I do that, is it possible?

And can i remove it via a plugin?

Thanks

Answer 1

It's not possible to remove it with remove_action() the way you've written it.

When you hooked it here:

add_action( 'woocommerce_shop_loop_item_title', array( $this, 'change_title' ), 10 );

The $this means that the function that's hooked is on this specific instance of My_class. When using remove_action() you need to pass the same instance of the class:

remove_action( 'woocommerce_before_shop_loop_item_title', array( $instance, 'change_title' ), 10 );

(where $instance is the instance of the class).

The problem is that the instance of the class is not available anywhere else because you've instantiated into nothing:

return new My_class();

To remove the action you need to put the class instance into a variable and then use that variable to remove it later:

$my_class = new My_class();

Then in your other code:

global $my_class;

remove_action( 'woocommerce_before_shop_loop_item_title', array( $my_class, 'change_title' ), 10 );

Another option is that if change_title is static then you don't need a specific instance of the class to add and remove it from hooks.

So make the function static:

public static function change_title() {
    echo 'The title';
}

Then to hook a static method you do this:

add_action( 'woocommerce_shop_loop_item_title', array( 'My_class', 'change_title' ), 10 );

Which means you can remove it like this:

remove_action( 'woocommerce_before_shop_loop_item_title', array( 'My_class', 'change_title' ), 10 );

But whether your class/functions can or should be static is a larger architectural question that would depend on exactly what you're doing.