Question

I can’t seem to figure out how to implement hook_menu_alter() to control access to a node. I’ve started with a bare Drupal 7 install, created two nodes, and created a module with only this code:

function mymodule_menu_alter(&$items){
    $items['node/2']['access callback'] = TRUE;
}

This should simulate an actual callback function returning TRUE, which is where I started off. But I’m trying to show the simplest possible case, here.

If I set the access callback to “FALSE”, it works as expected: I get “access denied” on node/2. But if I set it to TRUE, shouldn’t I just get normal access to the node? Instead, when I go to node/2, I get a page similar to (but not exactly the same as) the default front page: a list of node teasers (In this case, showing the two nodes I created).

I have cleared the cache (because I know hook_menu_alter() isn’t called on every page view, but IS when the cache is cleared). I’ve also rebuilt permissions, to no avail. I’m sure I’m missing something dumb here, but I just can’t think of it.

I also tried it with an actual callback:

function mymodule_menu_alter(&$items){
    $items['node/2']['access callback'] = 'mymodule_access_check';
}
function mymodule_access_check() {
    return TRUE;
}

Answer 1

node/2 isn’t a menu item. The menu item for a node is actually node/%, so to change it’s callback you would have to do this:

/**
 * Implements hook_menu_alter().
 */
function mymodule_menu_alter(&$items) {
  $items['node/%node']['access callback'] = 'mymodule_access_check';
}

function mymodule_access_check($op, $node) {
  if ($node->nid == 2 && $some_condition) {
    return TRUE;
  }
  else {
    return FALSE;
  }
}

Note I added $op (which will be ‘view’) and $node (which will be loaded node object) to the functions args because they will be passed to it by ‘access arguments’, so in your mymodule_access_check function you have access to the node information.