do_action inside class issue with add_meta_boxes hook - php

Question

Ok, this is a little specific. I might be missing something but since it killed me enough time , even though I found a way around it, I need to know if there's a way to do it properly.
Basically I want to use add_meta_box (http://codex.wordpress.org/Function_Reference/add_meta_box ) inside a class.
What I am doing:
//an array variable I am trying to pass in the class to a callback function as a parameter
$the_array = array(
'something',
'my meta box'
);
//a class where everything happens
class some_class {
//public function that has the array and initiates the add_meta_boxes hook
public function add_box($class_array) {
//add meta boxes hook to add the meta box properly
add_action('add_meta_boxes', array($this, 'adding_custom_meta_boxes'), 10, 2);
//passing the array variable to the callback function
do_action('add_meta_boxes',$class_array);
}
//the callback function of the add_meta_boxes hook
public function adding_custom_meta_boxes($class_array) {
add_meta_box('my-meta-box', __($class_array[1]), 'render_my_meta_box', 'page', 'normal', 'default');
}
public function render_my_meta_box(){
//the code to generate the html of the meta box goes here
}
}
$class_var = new some_class();
$class_var->add_box($the_array);
I get this error:
Fatal error: Call to undefined function add_meta_box() in C:\xampp\ht.....
but only if I use do_action to pass the variables to the hook callback function
I found a way around it with global variables, but , does anybody know a correct way of doing this?
I am trying to create the meta box from inside a class and this happens. It works well from outside a class. Anybody any ideas?

Answer 1

your not too far off. to correct the above change to this:
public function adding_custom_meta_boxes($class_array) {
add_meta_box('my-meta-box', __($class_array[1]), array($this, 'render_my_meta_box'), 'page', 'normal', 'default');
}
remove "do_action"
do_action tells the script to perform the attached actions right now and the function add_meta_boxes has yet to load (google the load process for wp functions). Thats the whole point of add_actions / Filters!