WordPress_Class_Helpers.php

<?php

/*
 * tl;dr
 * Adding `Helpers::add_hooks($this);` to your class constructor loads any needed add_action and add_filters hooks.
 */

class Class_Helpers {

	/**
	 * Takes in a class and parses each of the class' method names
	 * looking for action or filters and generating add_action or add_filters.
	 *
	 * A method named `action_init` would generate:
	 * add_action( 'init', array( $class_object, 'init' ), 10, 1 );
	 *
	 * A method named `action_init_5_8` would generate:
	 * add_action( 'init', array( $class_object, 'init' ), 5, 8 );
	 *
	 * If you include the priority you must include the accepted_args number.
	 *
	 * If you add the following in your class' constructor all needed
	 * add_action and add_filters calls are generated.
	 *
	 * Helpers::add_hooks( $this );
	 *
	 * @param $class_object
	 */
	public static function add_hooks( $class_object ) {

		$method_names = get_class_methods( get_class( $class_object ) );

		foreach ( $method_names as $method_name ) {

			$hook = self::parse_method( $method_name );

			if ( $hook && 'action' === $hook->type ) {
				add_action( $hook->name, array( $class_object, $method_name ), $hook->priority, $hook->accepted_args );
			}

			if ( $hook && 'filter' === $hook->type ) {
				add_filter( $hook->name, array( $class_object, $method_name ), $hook->priority, $hook->accepted_args );
			}
		}
	}

	public static function parse_method( $method_name ) {

		$is_action = 0 === strpos( $method_name, 'action_' );
		$is_filter = 0 === strpos( $method_name, 'filter_' );

		if ( $is_action || $is_filter ) {

			$method_name = substr( $method_name, 7 );

			$matches = array();
			preg_match( '/_\d+_\d+$/', $method_name, $matches );

			$priority      = 10;
			$accepted_args = 1;

			if ( count( $matches ) ) {
				list( $priority, $accepted_args ) = array_values( array_filter( explode( '_', $matches[0] ) ) );
				$method_name = substr( $method_name, 0, - 1 * strlen( $matches[0] ) );
			}

			return (object) array(
				'type'          => $is_action ? 'action' : 'filter',
				'name'          => $method_name,
				'priority'      => $priority,
				'accepted_args' => $accepted_args
			);

		}

		return null;

	}

}