It is possible to set up a menu item with hook_menu that points to an existing path?

Question

The accepted answer here by marcvangend explains how to it with hook_menu_alter. His method works, even if you skip step one (the block View).

But just out of interest: Can you do this by means of hook_menu?

So far, I've tried to put the following in hook_menu:

$items['node/%node/delete'] = array(
  'title' => 'Delete',
  'access callback' => TRUE,
  'type' => MENU_LOCAL_TASK,
);

However, that did not have any effect.

(Just to make clear, I just want the "Delete" tab, pointing to this existing path node/%node/delete. I don't want to put a view on it.)

Answer 1

You can only use hook_menu() if you're defining new paths, ideally, paths that are provided by the module implementing the hook.

If you want the Delete link to show up as a tab, hook_menu_alter is definitely the way to go, and adjusting the context value is what does the magic - as per Step 2 from marcvangend's post. If you want to change the "access callback" as per your snippet, then you can do that in hook_menu_alter() too, although I'm not sure why you'd want to let anyone delete pages?

Answer 2

One of the functions that invokes hook_menu(), menu_router_build(), uses the following code.

  $callbacks = array();
  foreach (module_implements('menu') as $module) {
    $router_items = call_user_func($module . '_menu');
    if (isset($router_items) && is_array($router_items)) {
      foreach (array_keys($router_items) as $path) {
        $router_items[$path]['module'] = $module;
      }
      $callbacks = array_merge($callbacks, $router_items);
    }
  }
  // Alter the menu as defined in modules, keys are like user/%user.
  drupal_alter('menu', $callbacks);

Since the code is using array_merge(), when two modules define a menu for the same path, only the last executed module would set the menu used by Drupal.

Modules should not rely on this, anyway. The correct way to alter a menu defined from another module is using the relative alter hook.