Drupal 7 Module Development

Node Access
Now we have an advanced rule set that gives us a great deal of flexibility, and you
have two new hooks in your Drupal toolkit.
Testing and debugging your module
Testing and debugging node access modules presents a particular challenge in
Drupal, largely because most access rules are user-based. That fact, combined with
user 1's ability to bypass all access checks, means that you cannot test node access
module through the browser while logged in as user 1. Nor can you test while
logged in as any user who has the bypass node access permission, since that
permission causes the entire node access system to be ignored, granting the user
View, Update, and Delete permission to all nodes.
While we don't have space to write up a Simpletest suite for our module here, there
are a few simple tricks you can remember to make your development (and support!)
life easier.
• Never test as user 1 or a user who can bypass node access.
• You can use hook_node_load() and hook_node_view() to append your
modules rule set to the node object for display. If you do so, be sure only to
display this information to trusted users.
• Remember to examine the contents of {node_access} after a node is saved.
Be sure the rules in the table reflect the logic of your code.
• Be sure that the data you need to store your rules is loaded onto the $node
object so you can safely rebuild {node_access} when you need to.
• Be sure to test access to both published and unpublished content.
These guidelines will help, but there is a better, faster, and easier way to debug your
working code.
Using Devel Node Access
The Devel Node Access module is part of the Devel module suite (http://drupal.
org/project/devel). The module is maintained by salvis (http://drupal.org/
user/82964) and gives you a browser-based view into how node access rules are
being enforced on your site.
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