8.3.x module.api.php hook_uninstall()
8.0.x module.api.php hook_uninstall()
8.1.x module.api.php hook_uninstall()
8.2.x module.api.php hook_uninstall()
8.4.x module.api.php hook_uninstall()
5.x install.php hook_uninstall()
6.x install.php hook_uninstall()
7.x system.api.php hook_uninstall()

Remove any information that the module sets.

The information that the module should remove includes:

The module should not remove its entry from the {system} table. Database tables defined by hook_schema() will be removed automatically.

The uninstall hook must be implemented in the module's .install file. It will fire when the module gets uninstalled but before the module's database tables are removed, allowing your module to query its own tables during this routine.

When hook_uninstall() is called, your module will already be disabled, so its .module file will not be automatically included. If you need to call API functions from your .module file in this hook, use drupal_load() to make them available. (Keep this usage to a minimum, though, especially when calling API functions that invoke hooks, or API functions from modules listed as dependencies, since these may not be available or work as expected when the module is disabled.)

See also

hook_install()

hook_schema()

hook_disable()

hook_modules_uninstalled()

Related topics

22 functions implement hook_uninstall()

Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.

aggregator_uninstall in modules/aggregator/aggregator.install
Implements hook_uninstall().
blog_uninstall in modules/blog/blog.install
Implements hook_uninstall().
book_uninstall in modules/book/book.install
Implements hook_uninstall().
comment_uninstall in modules/comment/comment.install
Implements hook_uninstall().
contact_uninstall in modules/contact/contact.install
Implements hook_uninstall().

... See full list

1 invocation of hook_uninstall()
drupal_uninstall_modules in includes/install.inc
Uninstalls a given list of disabled modules.

File

modules/system/system.api.php, line 3641
Hooks provided by Drupal core and the System module.

Code

function hook_uninstall() {
  variable_del('upload_file_types');
}

Comments

pillarsdotnet’s picture

The code inside a hook_uninstall() implementation should not call any API functions that are provided by any .module file, including its own, unless:

  1. The uninstall code explicitly loads the module file, e.g., by calling drupal_load().
  2. It is absolutely certain that the called API function does not rely on other API functions which may not be available.

See also:

kingandy’s picture

This is sort of assumed knowledge but, like hook_install and hook_update_N, this function should live in a .install file.

Karlheinz’s picture

Due to a bug in Drupal core, comments aren't unistalled properly. You'll likely get the error in the subject line.

Here is a temporary fix, until core is patched:

<?php
  $instance = array(
    'field_name' => 'comment_body',
    'bundle' => 'comment_node_' . $my_node_type,
    'entity_type' => 'comment',
  );
  field_delete_instance($instance);
?>

I got the code from here:
http://public-action.org/content/drupal-7-field-api-drupal-7-adding-cust...

Karlheinz’s picture

Apologies; the above code does not work - you still get the error.

For the record, I also tried adding field_delete_field('comment_node_' . $my_node_type) afterwards; still no luck.

charubachi’s picture

Can we use hook_uninstall for schema with foreign_key?