drupal钩子函数及其参数

Question

I'm reading through Pro Drupal development right now, and an example on page 82 uses the following function:

function menufun_menu_link_alter(&$item, $menu){  
  if ($item['link_path'] == 'logout'){  
    $item['link_title'] = 'Sign off';  
  }
}

I understand that I can find out what parameters "hook_menu_link_alter" takes by looking at api.drupal.org. What I don't understand is how I'm supposed to find out what $item actually contains. In this example, $item['link_path'] and $item['link_title'] were both used - how did he know they existed?

I'm not only interested in this specific example, of course. I want to be able to do this for any function that I look at in drupal.

Thanks in advance for the help!

Answer 1

If you went to api.drupal.org and looked up hook_menu_link_alter, you'd get this page:

http://api.drupal.org/api/function/hook_menu_link_alter/6

Which includes the following note:

"$item Associative array defining a menu link as passed into menu_link_save()."

If you follow the link to the menu_link_save page, you'd be here:

http://api.drupal.org/api/function/menu_link_save/6

In which the contents of the $item parameter is clearly listed under Parameters.