Wordpress - Using save_post to replace the post's title
This simplest method would be to edit the data at the point it's inserted, rather than updating it afterwards, using wp_insert_post_data
instead of save_post
. This works on creating a new post or updating an existing post without change. It also avoids the danger of creating an infinite loop by triggering update_post
within save_post
.
add_filter( 'wp_insert_post_data' , 'modify_post_title' , '99', 1 ); // Grabs the inserted post data so you can modify it.
function modify_post_title( $data )
{
if($data['post_type'] == 'rating' && isset($_POST['rating_date'])) { // If the actual field name of the rating date is different, you'll have to update this.
$date = date('l, d.m.Y', strtotime($_POST['rating_date']));
$title = 'TV ratings for ' . $date;
$data['post_title'] = $title ; //Updates the post title to your new title.
}
return $data; // Returns the modified data.
}
I had the exact same need, so I wrote this function - which works. Modify it to your needs. Hope this helps.
// set daily rating title
function set_rating_title ($post_id) {
if ( $post_id == null || empty($_POST) )
return;
if ( !isset( $_POST['post_type'] ) || $_POST['post_type']!='rating' )
return;
if ( wp_is_post_revision( $post_id ) )
$post_id = wp_is_post_revision( $post_id );
global $post;
if ( empty( $post ) )
$post = get_post($post_id);
if ($_POST['rating_date']!='') {
global $wpdb;
$date = date('l, d.m.Y', strtotime($_POST['rating_date']));
$title = 'TV ratings for ' . $date;
$where = array( 'ID' => $post_id );
$wpdb->update( $wpdb->posts, array( 'post_title' => $title ), $where );
}
}
add_action('save_post', 'set_rating_title', 12 );
Here's a solution that uses a static variable to prevent an infinite loop. This allows you to safely call wp_update_post()
inside of a function that is hooked to save_post
.
function km_set_title_on_save( $post_id ) {
// Set this variable to false initially.
static $updated = false;
// If title has already been set once, bail.
if ( $updated ) {
return;
}
// Since we're updating this post's title, set this
// variable to true to ensure it doesn't happen again.
$updated = true;
$date = get_post_meta( $post_id, 'rating_date', true );
$date_formatted = date( 'l, d.m.Y', strtotime( $date ) );
// Update the post's title.
wp_update_post( [
'ID' => $post_id,
'post_title' => 'TV ratings for ' . $date_formatted,
] );
}
add_action( 'save_post', 'km_set_title_on_save' );
Note: To limit this functionality to a certain post type, use the save_post_{$post->post_type} hook instead of save_post.