API@RTK0.NET

1. drupal
   1. 4.7 node.php
   2. 5 node.php
   3. 6 node.php
   4. 7

Perform node validation before a node is created or updated.

This hook is invoked only on the module that defines the node's content type (use hook_node_validate() to act on all node validations).

This hook is invoked from node_validate(), after a user has finished editing the node and is previewing or submitting it. It is invoked at the end of all the standard validation steps, and before hook_node_validate() is invoked.

To indicate a validation error, use form_set_error().

Note: Changes made to the $node object within your hook implementation will have no effect. The preferred method to change a node's content is to use hook_node_presave() instead.

Parameters

$node The node being validated.

$form The form being used to edit the node.

$form_state The form state array.

Related topics

Node API Hooks

Functions to define and modify content types.

Hooks

Allow modules to interact with the Drupal core.

Code

drupal/modules/node/node.api.php, line 1210

<?php
function hook_validate($node, $form, &$form_state) {
  if (isset($node->end) && isset($node->start)) {
    if ($node->start > $node->end) {
      form_set_error('time', t('An event may not end before it starts.'));
    }
  }
}
?>