hook_node_validate called on delete?

Question

Why is my hook_node_validate implementation being called when I try to delete a node through the node editing form (by clicking the delete button at the bottom of form)? Validation fires and then my node doesn't get deleted which is not what I want.

I can delete without any problems when clicking on delete link at admin/content but not whenclicking delete button on node edit form since validation fires and fails. What could be the reason for validation firing here?

Answer 1

nmc is right, validate functions are called for delete button as well, see http://drupal.org/node/216064 for more details

Answer 2

You could check the Triggering element in the Form State for the button that triggers the Form Submission.

function MYMODULE_node_validate($node , $form_state , $form) {
  if ($form_state['triggering_element']['#value'] != 'Delete') {
    //Include the validations here
  }
}

Answer 3

It's not invoked when deleting a node, basing on the code for node_delete_multiple(); the only functions called from that function that involve hooks are the following ones:

    node_invoke($node, 'delete');
    module_invoke_all('node_delete', $node);
    module_invoke_all('entity_delete', $node, 'node');
    field_attach_delete('node', $node);

The function is called from node_delete().

Looking at the code for node_delete_confirm_submit(), the form submission hander executed when a node is being deleted from the node edit form through the "Delete" button, I notice the following code:

$node = node_load($form_state['values']['nid']);
node_delete($form_state['values']['nid']);

That would cause the implementations of hook_node_load() to be invoked, but as far as I can see, it would not cause hook_node_validate() (which is invoked from node_validate()) to be invoked.

Answer 4

For fix that, you can do this:

function [mymodule]_form_alter(&$form, &$form_state, $form_id) {
  // For articles for example:
  if ($form_id == 'article_node_form') {
    $form['#validate'][] = 'myfunction_for_validate_article';
  }
} 

function myfunction_for_validate_article($form, &$form_state) {
  // This only will be call on insert and update.
} 

Source: http://befused.com/drupal/form-validation

Answer 5

In Drupal 7 you can suppress validation on all node edit Delete buttons with this code in a custom module:

/**
 * Implements hook_form_FORM_ID_alter().
 * 
 * Suppress validation for Delete button.
 */
function MYMODULE_form_node_form_alter(&$form, &$form_state, $form_id) {
  $form['actions']['delete']['#limit_validation_errors'] = [];
}