Sending an Email When New Posts Are Added in WordPress

send-email-new-post.php

// Hook to the post insertion action, to trigger a notification on certain post types
add_action('wp_insert_post', 'notify_admin_for_new_post', 10, 3);

function notify_admin_for_new_post($post_id, $post, $update)
{
    // Check for a specific custom post type and if the post is being published for the first time
    if ($post->post_type == 'custom_post_type' && $post->post_status == 'publish' && empty(get_post_meta($post_id, 'check_if_run_once'))) {
        // Initialize variables
        $organizer = '';
        $post_title = get_the_title(); // Assuming it's the title of the post
        $event_date = '';
        $location = '';
        $date_published = get_the_date();
        $categories = get_the_terms(get_the_ID(), 'custom_taxonomy');

        // Retrieve post meta
        $meta = get_post_meta(get_the_ID());

        if (isset($meta)) {
            // Process organizer information if available
            $organizer_ids = $meta['custom_organizer_meta_key'];
            if (isset($organizer_ids)) {
                $organizer = html_entity_decode(get_the_title($organizer_ids[0]));
            } else {
                $organizer = 'Not Found';
            }

            // Process event date information if available
            $event_date_info = $meta['custom_date_meta_key'];
            $event_date = isset($event_date_info) ? $event_date_info[0] : "Not Found";

            // Process location information if available
            $location_id = $meta['custom_location_meta_key'];
            $location = isset($location_id) ? html_entity_decode(get_the_title($location_id[0])) : "Not Found";
        }

        // Compose the subject and message of the email
        $subject = 'Notification - New Post - ' . $organizer;
        $message = 'A new post has been published.';
        // ... (construct the rest of the message)

        // Send the email
        $to = get_bloginfo('admin_email');
        $headers = array('Content-Type: text/html; charset=UTF-8');
        wp_mail($to, $subject, $message, $headers);

        // Update the post meta to prevent this notification from running again
        update_post_meta($post_id, 'check_if_run_once', true);
    }
}