uninstall.php

<?php

//if uninstall not called from WordPress exit
if (!defined('WP_UNINSTALL_PLUGIN'))
    exit();

/*
 * manages Polylang uninstallation
 * the goal is to remove ALL Polylang related data in db
 *
 * @since 0.5
 */
class PLL_Uninstall {

	/*
	 * constructor: manages uninstall for multisite
	 *
	 * @since 0.5
	 */
	function __construct() {
		global $wpdb;

		// check if it is a multisite uninstall - if so, run the uninstall function for each blog id
		if (is_multisite()) {
			foreach ($wpdb->get_col("SELECT blog_id FROM $wpdb->blogs") as $blog_id) {
				switch_to_blog($blog_id);
				$this->uninstall();
			}
			restore_current_blog();
		}
		else
			$this->uninstall();
	}

	/*
	 * removes ALL plugin data
	 *
	 * @since 0.5
	 */
	function uninstall() {
		// suppress data of the old model < 1.2
		// FIXME: to remove when support for v1.1.6 will be dropped
		global $wpdb;
		$wpdb->termmeta = $wpdb->prefix . 'termmeta'; // registers the termmeta table in wpdb

		// do nothing if the termmeta table does not exists
		if (count($wpdb->get_results("SHOW TABLES LIKE '$wpdb->termmeta'"))) {
			$wpdb->query("DELETE FROM $wpdb->postmeta WHERE meta_key = '_translations'");
			$wpdb->query("DELETE FROM $wpdb->termmeta WHERE meta_key = '_language'");
			$wpdb->query("DELETE FROM $wpdb->termmeta WHERE meta_key = '_rtl'");
			$wpdb->query("DELETE FROM $wpdb->termmeta WHERE meta_key = '_translations'");

			// delete the termmeta table only if it is empty as other plugins may use it
			if (!$wpdb->get_var("SELECT COUNT(*) FROM $wpdb->termmeta;"))
				$wpdb->query("DROP TABLE $wpdb->termmeta;");
		}


		// need to register the taxonomies
		$pll_taxonomies = array('language', 'term_language', 'post_translations', 'term_translations');
		foreach ($pll_taxonomies as $taxonomy)
			register_taxonomy($taxonomy, null , array('label' => false, 'public' => false, 'query_var' => false, 'rewrite' => false));


		$languages = get_terms('language', array('hide_empty'=>false));

		// delete users options
		foreach (get_users(array('fields' => 'ID')) as $user_id) {
			delete_user_meta($user_id, 'user_lang');
			delete_user_meta($user_id, 'pll_filter_content');
			foreach ($languages as $lang)
				delete_user_meta($user_id, 'description_'.$lang->slug);
		}

		// delete menu language switchers
		$ids = get_posts(array(
			'post_type'   => 'nav_menu_item',
			'numberposts' => -1,
			'nopaging'    => true,
			'fields'      => 'ids',
			'meta_key'    => '_pll_menu_item'
		));

		foreach ($ids as $id)
			wp_delete_post($id, true);

		// delete the strings translations (<1.2)
		// FIXME: to remove when support for v1.1.6 will be dropped
		foreach ($languages as $lang)
			delete_option('polylang_mo'.$lang->term_id);

		// delete the strings translations 1.2+
		register_post_type('polylang_mo', array('rewrite' => false, 'query_var' => false));
		$ids = get_posts(array(
			'post_type'   => 'polylang_mo',
			'numberposts' => -1,
			'nopaging'    => true,
			'fields'      => 'ids',
		));
		foreach ($ids as $id)
			wp_delete_post($id, true);

		// delete all what is related to languages and translations
		foreach (get_terms($pll_taxonomies, array('hide_empty'=>false)) as $term) {
			$term_ids[] = (int) $term->term_id;
			$tt_ids[] = (int) $term->term_taxonomy_id;
		}

		if (!empty($term_ids)) {
			$term_ids = array_unique($term_ids);
			$wpdb->query("DELETE FROM $wpdb->terms WHERE term_id IN (" . implode(',', $term_ids) . ")");
			$wpdb->query("DELETE FROM $wpdb->term_taxonomy WHERE term_id IN (" . implode(',', $term_ids) . ")");
		}

		if (!empty($tt_ids)) {
			$tt_ids = array_unique($tt_ids);
			$wpdb->query("DELETE FROM $wpdb->term_relationships WHERE term_taxonomy_id IN (" . implode(',', $tt_ids) . ")");
		}

		// delete options
		delete_option('polylang');
		delete_option('widget_polylang'); // automatically created by WP
		delete_option('polylang_wpml_strings'); // strings registered with icl_register_string

		//delete transients
		delete_transient('pll_languages_list');
		delete_transient('pll_upgrade_1_4');
	}
}

new PLL_Uninstall();