Manual Deny Delete Hook

[dwinders]

Currently you are able to delete a content type even though it's being referenced from another content type. It would be great if there was a way to manually limit that functionality via a pre_delete hook to enforce data integrity within relationships.

If you could create something like the code snippet below in https://github.com/pods-framework/pods/blob/2.x/classes/PodsAPI.php#L5512. That would be much appreciated.

$pre_delete = apply_filters( 'pods_api_delete_pod_item_pre_delete', null, $params );

if ( null !== $pre_delete ) {
    return $pre_delete;
}

[quasel]

Well if you are using bi directional relationships it's removed on the other side - but I can see a use case a use case for it, related to #5085 - at least add a warning like are you sure ;) …

thoughts @pglewis ?

[dwinders]

Yea If it could say something like the message below that would be super helpful.

"Are you sure you want to delete this resource? It is referenced in:
1. [post title]
2. [post title]
"

[macaranduba]

Hi! I crossed the same issue (https://wordpress.org/support/topic/delete-pod-used-as-a-related-to-field-in-another-pod/).

I tried some WP and PODs FW hooks and played with PODs metadata and here is what I came up with.
I couldn't find a hook triggered before the post delete action, so i'm using a hook fired after the post has been deleted.:

1. After a post has been deleted, check if it is a POD post;
2. If it is, check if the deleted POD is used as a required related field for another POD type;
3. If it is, check if there is another POD item using the "to be deleted" POD item as related field value;
4. If it is, set the deleted post status back to publish and alert the user for trying to delete a POD that is being used a required relationship field in another POD.

I just put the following code in theme file functions.php. I had to play with WP user session variables and administration notices to make it work.

/* Avoid removing POD item used as related field of another POD item */
//add_action( 'before_delete_post', 'checkIfPodIsInUse' );
//add_action( 'trash_post', 'checkIfPodIsInUse' );
//add_action( 'wp_trash_post', 'checkIfPodIsInUse' );
//add_action( 'delete_post', 'checkIfPodIsInUse' );
//add_action( 'save_post' , 'checkIfPodIsInUse' );
add_action( 'trashed_post', 'checkIfPodIsInUse' ); // triggered after the post has been trashed
function checkIfPodIsInUse( $post_id ) {
	$post_type = get_post_type($post_id);
	$my_pod = pods( $post_type, $post_id );
if( isBeingUsed($my_pod, $post_type)) {
		wp_redirect( home_url( 'wp-admin/edit.php?post_status=publish&post_type=' . $post_type ) );
		$my_pod->save('post_status', 'publish');
		//die("my_pod = " . $my_pod); // didn't the job, neither wp_die();
		exit();
	}
}

define("MAX_IN_USE_PODS", 10); // how many PODs, at most to show to the user, that are using the POD being deleted
function isBeingUsed($pod_2check, $post_type_2check) {
	//$fp = fopen(dirname(__FILE__) .'/deletePodOutput.txt', 'w');
	$pods_in_use_array = array();

	if( $pod_2check->exists() ) { // its really a POD custom type
		$all_custom_post_types = get_post_types( array( /*'public' => true, */ '_builtin' => false), 'objects'); // can PODs be private?

		foreach( $all_custom_post_types as $custom_post_type ) {
			//fwrite($fp, print_r($custom_post_type, true));
			$custom_pod = pods($custom_post_type->name);
			if( $custom_pod ) { // we've got a POD
				foreach($custom_pod->fields() as $custom_pod_field) {
					//fwrite($fp, '$custom_pod_field=' . print_r($custom_pod_field, true));
					if($custom_pod_field['type'] == 'pick' AND $custom_pod_field['pick_val'] == $post_type_2check AND  $custom_pod_field['options']['required'] == 1) {
						//fwrite($fp, 'PT2C-' . $post_type_2check . '' CPT-'.$custom_post_type->name . ' CPF pv-' . $custom_pod_field['pick_val'] . '' CPF name-' . $custom_pod_field['name'] .PHP_EOL);

						// its a related field
						$params = array(
							'where' => $custom_pod_field['name'] . '.id = ' . $pod_2check->id()
						);
						$custom_pod->find($params);
						fwrite($fp, '$custom_pod->total()=' .$custom_pod->total() );
						while( $custom_pod->fetch() ) {
							//$_SESSION['deletedPodInUse'] = $custom_pod->id() . ' ' . home_url( 'wp-admin/wp-admin/post.php?post=' . $custom_pod->id() . '&action=edit' ) ; // show error notice
							$pods_in_use_array[] = 'Can\'t delete this POD because it\'s being related by pod <a href="'
								. home_url( '/wp-admin/post.php?post=' . $custom_pod->id() . '&action=edit' ) . '"> ' . $custom_pod->field('title') .'</a> of type ' .  $custom_post_type->labels->singular_name; // show error notice

							if( count($pods_in_use_array) == MAX_IN_USE_PODS ) {
								$_SESSION['deletedPodInUse'] = $pods_in_use_array;

								return true; // stop checking for more related PODs if we already have enough
							}
						}
					}
				}
			}
		}
	}
	$_SESSION['deletedPodInUse'] = $pods_in_use_array;
	return count($pods_in_use_array);
}

function pods_in_use_notice() {
	if( isset($_SESSION['deletedPodInUse']) )  {
		foreach( $_SESSION['deletedPodInUse'] as $error_message ) {
			?>
			<div class="notice notice-error is-dismissible">
				<p><?php _e( $error_message, 'custom_post_types_domain' ); ?></p>
			</div>
			<?php
		}
		unset($_SESSION['deletedPodInUse']);
	}
}
add_action( 'admin_notices', 'pods_in_use_notice' );

/* USER SESSION */
function myStartUserSession() {
	if(!session_id()) {
			session_start();
	}
}
add_action('init', 'myStartUserSession', 1);
function myEndUserSession() {
	session_destroy();
}
add_action('wp_logout', 'myEndUserSession');
add_action('wp_login', 'myEndUserSession');