run-on-uninstall.php

<?php
/**
 * Stuff to do on uninstall
 * @author pootlepress
 * @since 0.1.0
 */

//Don't proceed any further if it ain't called by uninstall
if ( ! defined( 'POOTLEPB_UNINSTALL' ) ) {
	die;
}

//If hard uninstall is set true by user
if ( get_option( 'pootlepb-hard-uninstall' ) ) {

	//Get all posts using page builder
	$pootlepb_unin_args = array(
		'post_type'  => get_post_types(),
		'meta_query' => array(
			array(
				'key'     => 'panels_data',
				'compare' => 'EXISTS',
			),
		)
	);

	//Run the query with args
	$pootlepb_unin_query = new WP_Query( $pootlepb_unin_args );

	//Loop through the posts
	foreach ( $pootlepb_unin_query->posts as $post ) {

		//Delete page builder data
		delete_post_meta( $post->ID, 'panels_data' );

	}

	//Remove the options we used
	delete_option( 'pootlepb_add_ons' );
	delete_option( 'pootlepb_display' );

	//Removing usermeta for visit count to new page
	global $wpdb;
	$wpdb->query( "DELETE FROM $wpdb->usermeta WHERE meta_key LIKE 'pootlepb_visit_count';" );

}