Node API Hooks

The Node API allows modules to define content types, to modify content types created in the user interface, and to modify content types created by other modules.

Each content type is maintained by a primary module, which is either node.module (for content types created in the user interface) or the module that implements hook_node_info() to define the content type.

During node operations (create, update, view, delete, etc.), there are several sets of hooks that get invoked to allow modules to modify the base node operation:

• Node-type-specific hooks: These hooks are only invoked on the primary module, using the "base" return component of hook_node_info() as the function prefix. For example, poll.module defines the base for the Poll content type as "poll", so during creation of a poll node, hook_insert() is only invoked by calling poll_insert().
• All-module hooks: This set of hooks is invoked on all implementing modules, to allow other modules to modify what the primary node module is doing. For example, hook_node_insert() is invoked on all modules when creating a poll node.
• Field hooks: Hooks related to the fields attached to the node. These are invoked from the field operations functions described below, and can be either field-type-specific or all-module hooks.
• Entity hooks: Generic hooks for "entity" operations. These are always invoked on all modules.

Here is a list of the node and entity hooks that are invoked, field operations, and other steps that take place during node operations:

• Creating a new node (calling node_save() on a new node):
  • field_attach_presave()
  • hook_node_presave() (all)
  • Node and revision records are written to the database
  • hook_insert() (node-type-specific)
  • field_attach_insert()
  • hook_node_insert() (all)
  • hook_entity_insert() (all)
  • hook_node_access_records() (all)
  • hook_node_access_records_alter() (all)
• Updating an existing node (calling node_save() on an existing node):
  • field_attach_presave()
  • hook_node_presave() (all)
  • Node and revision records are written to the database
  • hook_update() (node-type-specific)
  • field_attach_update()
  • hook_node_update() (all)
  • hook_entity_update() (all)
  • hook_node_access_records() (all)
  • hook_node_access_records_alter() (all)
• Loading a node (calling node_load(), node_load_multiple(), or entity_load() with $entity_type of 'node'):
  • Node and revision information is read from database.
  • hook_load() (node-type-specific)
  • field_attach_load_revision() and field_attach_load()
  • hook_entity_load() (all)
  • hook_node_load() (all)
• Viewing a single node (calling node_view() - note that the input to node_view() is a loaded node, so the Loading steps above are already done):
  • hook_view() (node-type-specific)
  • field_attach_prepare_view()
  • hook_entity_prepare_view() (all)
  • field_attach_view()
  • hook_node_view() (all)
• Viewing multiple nodes (calling node_view_multiple() - note that the input to node_view_multiple() is a set of loaded nodes, so the Loading steps above are already done):
  • field_attach_prepare_view()
  • hook_entity_prepare_view() (all)
  • hook_view() (node-type-specific)
  • field_attach_view()
  • hook_node_view() (all)
  • hook_node_view_alter() (all)
• Deleting a node (calling node_delete() or node_delete_multiple()):
  • Node is loaded (see Loading section above)
  • Node and revision information is deleted from database
  • hook_delete() (node-type-specific)
  • hook_node_delete() (all)
  • field_attach_delete()
• Deleting a node revision (calling node_revision_delete()):
  • Node is loaded (see Loading section above)
  • Revision information is deleted from database
  • hook_node_revision_delete() (all)
  • field_attach_delete_revision()
• Preparing a node for editing (calling node_form() - note that if it's an existing node, it will already be loaded; see the Loading section above):
  • hook_prepare() (node-type-specific)
  • hook_node_prepare() (all); if translation.module is enabled, this will also invoke hook_node_prepare_translation() on all modules.
  • hook_form() (node-type-specific)
  • field_attach_form()
• Validating a node during editing form submit (calling node_form_validate()):
  • hook_validate() (node-type-specific)
  • hook_node_validate() (all)
  • field_attach_form_validate()
• Searching (calling node_search_execute()):
  • hook_ranking() (all)
  • Query is executed to find matching nodes
  • Resulting node is loaded (see Loading section above)
  • Resulting node is prepared for viewing (see Viewing a single node above)
  • comment_node_update_index() is called.
  • hook_node_search_result() (all)
• Search indexing (calling node_update_index()):
  • Node is loaded (see Loading section above)
  • Node is prepared for viewing (see Viewing a single node above)
  • hook_node_update_index() (all)

Functions

Name	Location	Description
hook_delete	modules/node/node.api.php	Respond to node deletion.
hook_form	modules/node/node.api.php	Display a node editing form.
hook_insert	modules/node/node.api.php	Respond to creation of a new node.
hook_load	modules/node/node.api.php	Act on nodes being loaded from the database.
hook_node_delete	modules/node/node.api.php	Respond to node deletion.
hook_node_info	modules/node/node.api.php	Define module-provided node types.
hook_node_insert	modules/node/node.api.php	Respond to creation of a new node.
hook_node_load	modules/node/node.api.php	Act on nodes being loaded from the database.
hook_node_prepare	modules/node/node.api.php	Act on a node object about to be shown on the add/edit form.
hook_node_prepare_translation	modules/node/node.api.php	Act on a node object being cloned for translation.
hook_node_presave	modules/node/node.api.php	Act on a node being inserted or updated.
hook_node_revision_delete	modules/node/node.api.php	Respond to deletion of a node revision.
hook_node_search_result	modules/node/node.api.php	Act on a node being displayed as a search result.
hook_node_update	modules/node/node.api.php	Respond to updates to a node.
hook_node_update_index	modules/node/node.api.php	Act on a node being indexed for searching.
hook_node_validate	modules/node/node.api.php	Perform node validation before a node is created or updated.
hook_node_view	modules/node/node.api.php	Act on a node that is being assembled before rendering.
hook_node_view_alter	modules/node/node.api.php	Alter the results of node_view().
hook_prepare	modules/node/node.api.php	Act on a node object about to be shown on the add/edit form.
hook_ranking	modules/node/node.api.php	Provide additional methods of scoring for core search results for nodes.
hook_update	modules/node/node.api.php	Respond to updates to a node.
hook_validate	modules/node/node.api.php	Perform node validation before a node is created or updated.
hook_view	modules/node/node.api.php	Display a node.