Strange Page not Found, Permissions, Clear cache

Question

On my D7.80 I have developed a custom module:

    function wrong_answer_menu() {
    dd('it entered in hook menu');
  $items['wrong-answer/%id'] = array(
    'title' => t('Wrong Answer Dashboard'),
    'page callback' => 'wrong_answer_dashboard',
    'page arguments' => array(1),
    'access callback' => TRUE,
    'type' => MENU_LOCAL_TASK,
  );

  return $items;
}

/**
 * Callback: hook_menu.
 */
function wrong_answer_dashboard($node_param=NULL) {
dd('it entered in dashboard');
....
}

Everything was fine, I was developing the menu nicely accessing the mydomain.com/wrong-answer and everything was fine.

Then I wanted to add permissions to my custom module, so that only the admin can access this page hence I added the wrong_answer_permission function and in the dashboard function I checked if the user had permission to access the page

/**
 * Implements hook_permission().
 */
function wrong_answer_permission() {
  return array(
    'wrong_answer_' => array(
      'title' => t('View the wrong answer'),
    ),
  );
}

    function wrong_answer_dashboard($node_param=NULL) {
     dd('it entered in dashboard');
     if (!user_access('wrong_answer_admin')) {
      return;
     }
    ....
    }

At this stage, when I accessed the page mydomain.com/wrong-answer I could still access it even though I did not assign the permission to it. Then I cleared the cache from the Performance menu via the admin/config/development/performance, and then I got the error message

The requested page "/wrong-answer/717" could not be found.

I get the same error for acessing just mydomain.com/wrong-answer.

Then I thought it was all fine, I added the permission wrong_answer_admin to the admin role, but then I still got the same error "The requested page .... could not be found.

Afterwards, I:

• cleared the cached
• removed the code that I had added on the permission and checking the user access
• rebuild the registry_file by emptying the table and running the update.php
• assigned the permission to the wrong_answer_admin to all the roles, including anonymous role
• deleted the wrong_answer_admin row in the permissions table in the database
• disabled and re-enabled by custom module

but nothing worked, I still get the error "The requested page cannot be found".

Then I noticed the strangest thing, that whenever I would clear the cache at, I would would get an entry in the drupal_debug.txt

it entered in hook menu

I do not get this entry in the drupal_debug.txt when accessing the wrong-answer page, I only get it when clearing the cache.

Could you please help me understand what is going on? why can't I access the wrong-answer page anymore?

Many thanks

Answer 1

An answer to part of your question:

Then I noticed the strangest thing, that whenever I would clear the cache at, I would would get an entry in the drupal_debug.txt

it entered in hook menu

I do not get this entry in the drupal_debug.txt when accessing the wrong-answer page, I only get it when clearing the cache.

If Drupal built the menu for every page load, it would result in heavier page loads. As such, hook_menu() is only called after the cache is cleared, as the menu cache is rebuilt the first time it is needed and no cache exists. Once it's been cached, hook_menu() does not get called anymore.

Answer 2

It seems like that the problem will be in the menu item definition:

$items['wrong-answer/%id'] = array(

I do not think you can use random string in the wildcard placeholder. According to the documentation, you can:

1. Use plain wildcard (%) - this will pass the ID directly to your function.
2. Use auto-loader wildcard (for example %node) - but the name must reference an existing loading function. In this case the node_load() function will be called and the node object will be passed to your function.
3. Define %wildcard_to_arg() function (see documentation).

It is very likely that you do not have id_load() function in your code, so this should be the reason why this is not working. From the documentation:

... if a node with a node ID of 999 does not exist, 
the menu routing system will return a 404 error in this case...

If you change it to this, it should work correctly:

$items['wrong-answer/%'] = array(

See hook_menu documentation for additional information: https://api.drupal.org/api/drupal/modules!system!system.api.php/function/hook_menu/7.x