class-core.php

<?php

/**
 * Base class for Sublanguage_site in front-end and Sublanguage_admin in admin.
 */
class Sublanguage_core {


	/**
	 * @from 1.1
	 *
	 * @var string
	 */
	var $version = '2.13';

	/**
	 * @from 2.0
	 *
	 * @var string
	 */
	var $db_version = '2.0';

	/**
	 * @from 1.0
	 *
	 * @var array
	 */
	var $current_language;

	/**
	 * @from 1.1
	 *
	 * @var string
	 */
	var $language_query_var = 'language';

	/**
	 * @from 1.0
	 *
	 * @var string
	 */
	var $option_name = 'sublanguage';

	/**
	 * @from 1.0
	 *
	 * @var string
	 */
	var $language_post_type = 'language';

	/**
	 * @from 1.1
	 *
	 * @deprecated from 2.0. Use get_post_type_metakeys() instead.
	 * @var array
	 */
	private $postmeta_keys;

	/**
	 * @from 1.5
	 *
	 * @var array
	 */
	private $taxonomies;

	/**
	 * @from 1.5
	 *
	 * @deprecated from 2.0. Use is_post_type_translatable() instead.
	 * @var array
	 */
	private $post_types;

	/**
	 * @from 1.4
	 *
	 * @var array
	 */
	var $fields = array('post_content', 'post_name', 'post_excerpt', 'post_title');

	/**
	 * @from 2.0
	 *
	 * @var array
	 */
	var $taxonomy_fields = array('name', 'slug', 'description');

	/**
	 * @var string
	 *
	 * Prefix for creating language unique id.
	 *
	 * @deprecated from 2.0. Use get_prefix() instead. STILL NEEDED FOR COMPAT.
	 * @from 1.5.1
	 */
	var $translation_prefix = 'translation_';

	/**
	 * @var bool
	 *
	 * Control wether get_post_meta() is being translated
	 *
	 * @from 2.4
	 */
	var $translate_meta = true;

	/**
	 * Get option
	 *
	 * @param string $option_name. Option name
	 * @param mixed $default. Default value if option does not exist
	 * @return mixed
	 *
	 * @from 1.4.7
	 */
	public function get_option($option_name, $default = false) {

		$options = get_option($this->option_name);

		if (isset($options[$option_name])) {

			return $options[$option_name];

		}

		return $default;
	}

	/**
	 * Get current language
	 *
	 * @from 2.0
	 *
	 * @return object WP_post|false
	 */
	public function get_language() {

		if (!isset($this->current_language)) {

			$this->current_language = $this->request_language();

		}

		return $this->current_language;
	}

	/**
	 * Check wether current language is defined
	 *
	 * @from 2.0
	 *
	 * @return bool
	 */
	public function has_language() {

		return isset($this->current_language) && $this->current_language;

	}

	/**
	 * Set current language
	 *
	 * @from 2.0
	 *
	 * @param object WP_post $language Language. Optional
	 */
	public function set_language($language = null) {

		static $original;

		if (!isset($original)) {

			$original = $this->get_language();

		}

		if (empty($language)) {

			$language = $original;

		}

		$this->current_language = $language;
	}

	/**
	 * Restore original language after changing with set_language()
	 *
	 * @from 2.0
	 */
	public function restore_language() {

		$this->set_language();

	}

	/**
	 * Requestion current language
	 *
	 * @from 2.0
	 *
	 * @return object WP_post|false
	 */
	public function request_language() {

		if (isset($_REQUEST[$this->language_query_var])) {

			return $this->get_language_by($_REQUEST[$this->language_query_var], 'post_name');

		}

		return $this->get_main_language();
	}

	/**
	 * Get array of languages
	 *
	 * @return array of WP_post objects
	 *
	 * @from 1.2
	 * @from 2.5 only select language with post_status 'publish' or 'draft'
	 */
	public function get_languages() {
		global $wpdb;

		static $languages;

		if (!isset($languages)) {

			$languages = $wpdb->get_results( $wpdb->prepare(
				"SELECT post.ID, post.post_name, post.post_title, post.post_content, post.post_excerpt, post.menu_order, post.post_status FROM $wpdb->posts AS post
					WHERE post.post_type = %s AND (post_status = %s OR post_status = %s)
					ORDER BY post.menu_order ASC",
				$this->language_post_type,
				'publish',
				'draft'
			));

		}

		return $languages;
	}

	/**
	 * Select language object by translation post-type
	 *
	 * @deprecated from 1.5.1
	 * @from 1.1
	 *
	 * @param string $post_type.
	 * @return WP_Post object.
	 */
	public function get_language_by_type($post_type) {

		return $this->get_language_by($post_type, 'post_excerpt');

	}

	/**
	 * Select language object by translation taxonomy
	 *
	 * @deprecated from 1.5.1
	 * @from 1.1
	 *
	 * @param string $post_type.
	 * @return WP_Post object.
	 */
	public function get_language_by_taxonomy($taxonomy) {

		return $this->get_language_by($taxonomy, 'post_excerpt');

	}

	/**
	 * Get language by field.
	 * ID corresponds to language ID.
	 * post_name corresponds to language slug.
	 * post_content corresponds to language locale.
	 *
	 * @from 1.1
	 *
	 * @param string $val.
	 * @param string $key.
	 * @return false|WP_post object
	 */
	public function get_language_by($val, $key = 'post_name') {

		$languages = $this->get_languages();

		foreach ($languages as $lng) {

			if ($lng->$key == $val) return $lng;

		}

		return false;
	}

	/**
	 * get an array of all languages values for one field
	 *
	 *	@from 1.1
	 *
	 * @param string $column.
	 * @return array
	 */
	public function get_language_column($column) {

		$output = array();

		$languages = $this->get_languages();

		foreach ($languages as $lng) {

			$output[] = isset($lng->$column) ? $lng->$column : false;

		}

		return $output;
	}

	/**
	 * Get default language
	 *
	 * @from 1.2
	 *
	 * @return WP_Post object
	 */
	public function get_default_language() {

		return $this->get_language_by($this->get_option('default'), 'ID');

	}

	/**
	 * Get main language
	 *
	 * @from 1.2
	 *
	 * @return WP_Post object
	 */
	public function get_main_language() {

		return $this->get_language_by($this->get_option('main'), 'ID');

	}

	/**
	 * Get language tag
	 *
	 * @return string
	 *
	 * @from 2.5
	 */
	public function get_language_tag($language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		if ($language->post_excerpt) {

			return $language->post_excerpt;

		} else {

			return $language->post_name;

		}

	}

	/**
	 * Create prefix for translation meta keys
	 *
	 * @from 2.0
	 *
	 * @param string $language_slug
	 * @return string
	 */
	public function create_prefix($slug) {

		return '_' . $slug . '_';

	}

	/**
	 * Get prefix for translation meta keys
	 *
	 * @from 2.0
	 *
	 * @param object WP_Post $language. Optional
	 * @return string
	 */
	public function get_prefix($language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		if (empty($language)) {

			return false;

		}

		return $this->create_prefix($language->post_name);

	}

	/**
	 * Get post_type options for translation.
	 *
	 * @from 2.0
	 * @from 2.3. Remove filter 'sublanguage_post_type_default'. Use "sublanguage_default_$post_type_$option_name" instead
	 *
	 * @return mixed
	 */
	public function get_post_types_options() {

		static $post_types_options;

		if (!isset($post_types_options)) {

			$post_types_options = $this->get_option('post_type', array());

		}

		return $post_types_options;
	}

	/**
	 * Get post_type options for translation.
	 *
	 * @from 2.3
	 *
	 * @return mixed
	 */
	public function get_post_type_options($post_type, $default = array()) {

		$post_types_options = $this->get_post_types_options();

		if (isset($post_types_options[$post_type])) {

			$value = $post_types_options[$post_type];

		} else {

			/**
			 * Filter default post type option
			 *
			 * @from 2.3
			 *
			 * @param mixed. Default option
			 */
			$value = apply_filters("sublanguage_default-$post_type", $default);

		}

		return $value;
	}


	/**
	 * Get post_type single option for translation.
	 *
	 * @from 2.0
	 * @from 2.3. Use "sublanguage_default_$post_type_$option_name" filter
	 *
	 * @param string $post_type
	 * @param string $option_name. Accepts 'translatable', 'meta_keys', 'fields', 'title_cached', 'exclude_untranslated'
	 * @param mixed $fallback. Value returned when option is not defined.
	 *
	 * @return mixed
	 */
	public function get_post_type_option($post_type, $option_name, $fallback = false) {

		$post_type_options = $this->get_post_type_options($post_type);

		if (isset($post_type_options[$option_name])) {

			return $post_type_options[$option_name];

		}

		return $fallback;

	}

	/**
	 * Check if post_type is translatable.
	 *
	 * @from 2.0 $post_type should no longer be 'any' or array.
	 * @from 1.4.5
	 *
	 * @param string $post_type
	 *
	 * @return boolean
	 */
	public function is_post_type_translatable($post_type) {

		return $this->get_post_type_option($post_type, 'translatable');

	}

	/**
	 * Get post_type translatable meta keys.
	 *
	 * @from 2.0
	 *
	 * @param string $post_type
	 *
	 * @return array of strings
	 */
	public function get_post_type_metakeys($post_type) {

		return $this->get_post_type_option($post_type, 'meta_keys', array());

	}

	/**
	 * Get post_type translatable fields.
	 *
	 * @from 2.0
	 *
	 * @param string $post_type
	 *
	 * @return array of strings
	 */
	public function get_post_type_fields($post_type) {

		return $this->get_post_type_option($post_type, 'fields', $this->fields);

	}

	/**
	 * Check if post_type title is cached (for ordering)
	 *
	 * @from 2.0
	 *
	 * @param string $post_type
	 *
	 * @return boolean
	 */
	public function is_post_type_title_cached($post_type) {

		return $this->get_post_type_option($post_type, 'title_cached');

	}

	/**
	 * Get taxonomies options for translation.
	 *
	 * @from 2.0
	 * @from 2.3 remove filter "sublanguage_taxonomy_default" and default settings
	 *
	 * @return mixed
	 */
	public function get_taxonomies_options() {

		static $taxonomy_options;

		if (!isset($taxonomy_options)) {

			$taxonomy_options = $this->get_option('taxonomy', array());

		}

		return $taxonomy_options;
	}

	/**
	 * Get taxonomies options for translation.
	 *
	 * @from 2.3
	 *
	 * @return mixed
	 */
	public function get_taxonomy_options($taxonomy, $default = array()) {

		$taxonomies_options = $this->get_taxonomies_options();

		if (isset($taxonomies_options[$taxonomy])) {

			$value = $taxonomies_options[$taxonomy];

		} else {

			/**
			 * Filter default taxonomy options
			 *
			 * @from 2.3
			 *
			 * @param mixed. Default option
			 */
			$value = apply_filters("sublanguage_taxonomy_default-$taxonomy", $default);

		}

		return $value;

	}

	/**
	 * Get taxonomy single option for translation.
	 *
	 * @from 2.0
	 * @from 2.3. use filter "sublanguage_taxonomy_default-$taxonomy-$option_name"
	 *
	 * @param string $taxonomy
	 * @param string $option_name. Accepts 'translatable', 'meta_keys', 'fields'
	 * @param mixed $fallback. Value returned when option is not defined.
	 *
	 * @return mixed
	 */
	public function get_taxonomy_option($taxonomy, $option_name, $fallback = false) {

		$taxonomy_options = $this->get_taxonomy_options($taxonomy);

		if (isset($taxonomy_options[$option_name])) {

			return $taxonomy_options[$option_name];

		}

		return $fallback;
	}

	/**
	 * Check if taxonomy is translatable.
	 *
	 * @from 2.0 $taxonomy should no longer be an array.
	 * @from 1.4.5
	 *
	 * @param string $taxonomy
	 *
	 * @return boolean
	 */
	public function is_taxonomy_translatable($taxonomy) {

		return $this->get_taxonomy_option($taxonomy, 'translatable');

	}

	/**
	 * Get taxonomy translatable meta keys.
	 *
	 * @from 2.0
	 *
	 * @param string $taxonomy
	 *
	 * @return array of strings
	 */
	public function get_taxonomy_metakeys($taxonomy) {

		return $this->get_taxonomy_option($taxonomy, 'meta_keys', array());

	}

	/**
	 * Get taxonomy translatable fields.
	 *
	 * @from 2.0
	 *
	 * @param string $taxonomy
	 *
	 * @return array of strings
	 */
	public function get_taxonomy_fields($taxonomy) {

		return $this->get_taxonomy_option($taxonomy, 'fields', $this->taxonomy_fields);

	}


	/**
	 * Check whether language is main
	 *
	 * @from 2.0 Changed parameters
	 * @from 1.4.7
	 *
	 * @param object WP_Post $language Language. Optional
	 * @return boolean
	 */
	public function is_main($language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		return $language && $language->ID == $this->get_option('main');

	}

	/**
	 * Check whether language is sub-language
	 *
	 * @from 2.0 Changed parameters
	 * @from 1.4.7
	 *
	 * @param object WP_Post $language Language. Optional
	 * @return boolean
	 */
	public function is_sub($language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		return $language && $language->ID != $this->get_option('main');

	}

	/**
	 * Check whether language is default
	 *
	 * @from 2.0 Changed parameters
	 * @from 1.4.7
	 *
	 * @param object WP_Post $language Language. Optional
	 * @return boolean
	 */
	public function is_default($language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		return $language && $language->ID == $this->get_option('default');

	}

	/**
	 * Check whether language is current language.
	 *
	 * @from 1.4.7
	 *
	 * @param object WP_Post $language Language.
	 * @return boolean
	 */
	public function is_current($language) {

		return $language && $this->has_language() && $language->ID === $this->get_language()->ID;

	}

	/**
	 * Find a language by ID, slug, object or anything
	 *
	 * @from 2.0
	 *
	 * @param mixed $language Language object, id or anything. Optional.
	 * @param string $by Field to search language by. Accepts 'post_name', 'post_title', 'post_content'. Optional.
	 * @return WP_Post object|false
	 */
	public function find_language($language = null, $by = null) {

		if (empty($language)) {

			return $this->get_language();

		} else if (isset($by)) {

			$language_obj = $this->get_language_by($language, $by);

		} else if (is_int($language)) {

			$language_obj = $this->get_language_by($language, 'ID');

		} else if ($language instanceof WP_Post) {

    	return $language;

    }

		if (empty($language_obj)) {

			$language_obj = $this->get_language_by($language, 'post_name');

			if (empty($language_obj)) {

				$language_obj = $this->get_language_by($language, 'post_content');

				if (empty($language_obj)) {

					$language_obj = $this->get_language_by($language, 'post_title');

				}

			}

		}

		if (isset($language_obj)) {

			return $language_obj;

		}

		return false;
	}

	/**
	 * Check whether meta key is translatable
	 *
	 * @from 2.0
	 *
	 * @param string $meta_key Meta key
	 * @return boolean
	 */
	public function is_meta_key_translatable($post_type, $meta_key) {

		return $this->is_post_type_translatable($post_type) && in_array($meta_key, $this->get_post_type_metakeys($post_type));

	}

	/**
	 * Filter translatable taxonomies from array
	 *
	 * @from 1.4.6
	 *
	 * @param mixed string|array $taxonomies
	 * @return array
	 */
	public function filter_translatable_taxonomies($taxonomies) {

		if (!is_array($taxonomies)) {

			$taxonomies = array($taxonomies);

		}

		// return array_intersect($this->get_taxonomies(), $taxonomies);
	}

	/**
	 * Filter translatable post-types from post-types array
	 *
	 * @from 1.4.6
	 *
	 * @param mixed string|array $post_types
	 * @return array
	 */
	public function filter_translatable_post_types($post_types) {

		trigger_error('dont use filter_translatable_post_types anymore!');

	}

	/**
	 * get taxonomy translation
	 *
	 * @from 1.1
	 *
	 * @param string $original_taxonomy. Original taxonomy name (e.g 'category')
	 * @param int $language_id. Language id
	 * @return string|false Translated taxonomy if exists.
	 */
	public function get_taxonomy_translation($original_taxonomy, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		$translations = $this->get_option('translations', array());

		if ($language && isset($translations['taxonomy'][$original_taxonomy][$language->ID]) && $translations['taxonomy'][$original_taxonomy][$language->ID]) {

			return $translations['taxonomy'][$original_taxonomy][$language->ID];

		}

		return false;
	}

	/**
	 * Translate taxonomy
	 *
	 * @from 1.1
	 *
	 * @param string $original_taxonomy. Original taxonomy name (e.g 'category')
	 * @param int $language_id. Language id
	 * @param string $fallback
	 * @return string Translated taxonomy
	 */
	public function translate_taxonomy($original_taxonomy, $language = null, $fallback = null) {

		$translated_taxonomy = $this->get_taxonomy_translation($original_taxonomy, $language);

		if ($translated_taxonomy) {

			return $translated_taxonomy;

		} else if (isset($fallback)) {

			return $fallback;

		}

		return $original_taxonomy;
	}

	/**
	 * get original taxonomy
	 *
	 * @from 1.1
	 *
	 * @param string $translated_taxonomy. Translated taxonomy name (e.g 'categorie')
	 * @param int $language_id. Language id
	 * @return string Original taxonomy or false.
	 */
	public function get_taxonomy_original($translated_taxonomy, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		$translations = $this->get_option('translations', array());

		if (isset($translations['taxonomy'])) {

			foreach ($translations['taxonomy'] as $original => $translation) {

				if (isset($translation[$language->ID]) && $translation[$language->ID] === $translated_taxonomy) {

					return $original;

				}

			}

		}

    return false;
	}

	/**
	 * Translate custom post type
	 *
	 * @from 1.1
	 *
	 * @param string $original_cpt. Original custom post type name (e.g 'book')
	 * @param int $language_id. Language id
	 * @return string Translated cpt (may be equal to original).
	 */
	public function get_cpt_translation($original_cpt, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		$translations = $this->get_option('translations', array());

		if ($language && isset($translations['post_type'][$original_cpt][$language->ID]) && $translations['post_type'][$original_cpt][$language->ID]) {

			return $translations['post_type'][$original_cpt][$language->ID];

		}
		return false;

	}

	/**
	 * Translate custom post type
	 *
	 * @from 1.1
	 *
	 * @param string $original_cpt. Original custom post type name (e.g 'book')
	 * @param int $language_id. Language id
	 * @param string $fallback Fallback. Optional
	 * @return string Translated cpt (may be equal to original).
	 */
	public function translate_cpt($original_cpt, $language = null, $fallback = null) {

		$translated_cpt = $this->get_cpt_translation($original_cpt, $language);

		if ($translated_cpt) {

			return $translated_cpt;

		} else if (isset($fallback)) {

			return $fallback;

		}

		return $original_cpt;

	}

	/**
	 * get original custom post type
	 *
	 * @from 1.1
	 *
	 * @param string $translated_taxonomy. Translated custom post type name (e.g 'livre')
	 * @param int $language_id. Language id
	 * @return string|false
	 */
	public function get_cpt_original($translated_cpt, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		$translations = $this->get_option('translations', array());

		if ($language && isset($translations['post_type'])) {

			foreach ($translations['post_type'] as $original => $translation) {

				if (isset($translation[$language->ID]) && $translation[$language->ID] === $translated_cpt) {

					return $original;

				}

			}

    }

    return false;

	}

	/**
	 * get slug used by custom post type archive link
	 *
	 * @from 2.3
	 *
	 * @param string $original_cpt. Original custom post type name (e.g 'book')
	 * @param int $language_id. Language id
	 * @return string Translated cpt (may be equal to original).
	 */
	public function get_cpt_archive_translation($original_cpt, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		$translations = $this->get_option('translations', array());

		if ($language && isset($translations['cpt_archive'][$original_cpt][$language->ID]) && $translations['cpt_archive'][$original_cpt][$language->ID]) {

			return $translations['cpt_archive'][$original_cpt][$language->ID];

		}

		return false;
	}

	/**
	 * Translate slug used by custom post type archive link
	 *
	 * @from 2.3
	 *
	 * @param string $original_cpt. Original custom post type name (e.g 'book')
	 * @param int $language_id. Language id
	 * @param string $fallback Fallback. Optional
	 * @return string Translated cpt (may be equal to original).
	 */
	public function translate_cpt_archive($original_cpt, $language = null, $fallback = null) {

		$translated_cpt = $this->get_cpt_archive_translation($original_cpt, $language);

		if ($translated_cpt) {

			return $translated_cpt;

		} else if (isset($fallback)) {

			return $fallback;

		}

		return $this->translate_cpt($original_cpt, $language, $fallback);
	}

	/**
	 * get original custom post type by translated archive slug
	 *
	 * @from 2.3
	 *
	 * @param string $translated_taxonomy. Translated custom post type name (e.g 'livre')
	 * @param int $language_id. Language id
	 * @return string|false
	 */
	public function get_cpt_archive_original($translated_cpt_archive, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		$translations = $this->get_option('translations', array());

		if ($language && isset($translations['cpt_archive'])) {

			foreach ($translations['cpt_archive'] as $original => $translation) {

				if (isset($translation[$language->ID]) && $translation[$language->ID] === $translated_cpt_archive) {

					return $original;

				}

			}

    }

    return $this->get_cpt_original($translated_cpt_archive, $language);
	}


	/**
	 * get option translation
	 *
	 * @from 1.5
	 *
	 * @param int $language_id. Language id
	 * @return array
	 */
	public function get_option_translation($language_id, $option_name) {

		$translations = $this->get_option('translations', array());

		if (isset($translations['option'][$language_id][$option_name]) && $translations['option'][$language_id][$option_name]) {

			return $translations['option'][$language_id][$option_name];

		}

		return false;

	}

	/**
	 * get all options translations
	 *
	 * @from 1.5
	 *
	 * @return array
	 */
	public function get_option_translations() {

		$translations = $this->get_option('translations', array());

		if (isset($translations['option'])) {

			return $translations['option'];

		}

		return array();

	}

	/**
	 * get post field translation if it exists
	 *
	 * @from 2.0 Changed parameters
	 * @from 1.1
	 *
	 * @param object WP_Post $post Post to translate field.
	 * @param object WP_Post $language Language.
	 * @param string $field Field name. Accepts 'post_content', 'post_title', 'post_name', 'post_excerpt'
	 * @return string
	 */
	public function get_post_field_translation($post, $field, $language = null) {

		if ($this->is_sub($language) && $this->is_post_type_translatable($post->post_type) && in_array($field, $this->get_post_type_fields($post->post_type))) {

			return get_post_meta($post->ID, $this->get_prefix($language) . $field, true);

		} else {

			return $post->$field;

		}

	}

	/**
	 * get post field translation
	 *
	 * @from 2.0 Changed parameters
	 * @from 1.1
	 *
	 * @param object WP_Post $post Post to translate field.
	 * @param object WP_Post $language Language.
	 * @param string $field Field name. Accepts 'post_content', 'post_title', 'post_name', 'post_excerpt'
	 * @param string $fallback Defaut value to return when translation does not exist. Optional.
	 * @return string
	 */
	public function translate_post_field($post, $field, $language = null, $fallback = null) {

		$value = $this->get_post_field_translation($post, $field, $language);

		if ($value) {

			return $value;

		} else if (isset($fallback)) {

			return $fallback;

		}

		return $post->$field;

	}

	/**
	 * Check if post field is translated
	 *
	 * @param object WP_Post $post Post to translate field.
	 * @param string|mixed $field Field name. Accepts 'post_content', 'post_title', 'post_name', 'post_excerpt', an array of those, or null
	 * @param object WP_Post $language Language.
	 *
	 * @return boolean
	 *
	 * @from 2.5
	 */
	public function has_post_translation($post = null, $field = null, $language = null) {

		$post = get_post($post);

		if (is_string($field)) {

			return $this->get_post_field_translation($post, $field, $language) !== $post->$field;

		} else if (is_array($field)) {

			$fields = $field;

			foreach ($fields as $field) {

				if ($this->get_post_field_translation($post, $field, $language) === $post->$field) {

					return false; // at least one is not translated

				}

			}

			return true;

		} else {

			$fields = $this->fields;

			foreach ($fields as $field) {

				if ($this->get_post_field_translation($post, $field, $language) !== $post->$field) {

					return true; // at least one is translated

				}

			}

			return false;

		}

	}

	/**
	 * get term field translation if it exists
	 *
	 * @from 2.0
	 *
	 * @param object WP_Term $term.
	 * @param string $taxonomy.
	 * @param string $field. Accepts 'name', 'slug', 'description'
	 * @param object WP_Post $language.
	 * @return string
	 */
	public function get_term_field_translation($term, $taxonomy, $field, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		if ($this->is_sub($language) && $this->is_taxonomy_translatable($term->taxonomy)) {

			return get_term_meta($term->term_id, $this->get_prefix($language) . $field, true);

		} else {

			return $term->$field;

		}

	}

	/**
	 * Get term field translation
	 *
	 * @from 2.0 Changed parameters
	 * @from 1.1
	 *
	 * @param object WP_Term $term.
	 * @param string $taxonomy.
	 * @param string $field. Accepts 'name', 'slug', 'description'
	 * @param object WP_Post $language.
	 * @param string $fallback Defaut value to return when translation does not exist. Optional.
	 * @return string.
	 */
	public function translate_term_field($term, $taxonomy, $field, $language = null, $fallback = null) {

		$value = $this->get_term_field_translation($term, $taxonomy, $field, $language);

		if ($value) {

			return $value;

		} else if (isset($fallback)) {

			return $fallback;

		}

		return $term->$field;

	}

	/**
	 * Get untranslated post meta
	 *
	 * @from 2.4
	 */
	public function get_untranslated_post_meta($post_id, $meta_key, $single) {

		$this->translate_meta = false;

		$value = get_post_meta($post_id, $meta_key, $single);

		$this->translate_meta = true;

		return $value;
	}

	/**
	 * Get post meta translation if it exists
	 *
	 * @from 2.0
	 *
	 * @param object WP_Post $post Post to translate field.
	 * @param string $meta_key Meta key.
	 * @param bool $single Single meta value.
	 * @param object WP_Post $language Language.
	 * @return string|array|false
	 */
	public function get_post_meta_translation($post, $meta_key, $single, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		if ($this->is_main($language)) {

			return $this->get_untranslated_post_meta($post->ID, $meta_key, $single);

		} else if (in_array($meta_key, $this->get_post_type_metakeys($post->post_type))) {

			return get_post_meta($post->ID, $this->create_prefix($language->post_name) . $meta_key, $single);

		} else {

			return false;

		}

	}

	/**
	 * Translate post meta
	 *
	 * @param object WP_Post $post Post to translate field.
	 * @param string $meta_key Meta key.
	 * @param bool $single Single meta value.
	 * @param object WP_Post $language Language.
	 * @param string $fallback Fallback to return if no meta value.
	 * @return string|array
	 *
	 * @from 2.0 params changed
	 * @from 1.1
	 */
	public function translate_post_meta($post, $meta_key, $single, $language = null, $fallback = null) {

		$translation = $this->get_post_meta_translation($post, $meta_key, $single, $language);

		if ($translation) {

			return $translation;

		} else if (isset($fallback)) {

			return $fallback;

		}

		return get_post_meta($post->ID, $meta_key, $single);
	}

	/**
	 * Get term meta translation if it exists
	 *
	 * @from 2.0
	 *
	 * @param object WP_Term $term. Term to translate field.
	 * @param string $meta_key Meta key.
	 * @param bool $single Single meta value.
	 * @param object WP_Post $language Language.
	 * @return string|array
	 */
	public function get_term_meta_translation($term, $meta_key, $single, $language = null) {

		if (empty($language)) {

			$language = $this->get_language();

		}

		if ($this->is_sub($language) && in_array($meta_key, $this->get_taxonomy_metakeys($term->taxonomy))) {

			return get_term_meta($term->term_id, $this->create_prefix($language->post_name) . $meta_key, $single);

		} else {

			return false;

		}

	}

	/**
	 * Translate term meta
	 *
	 * @param object WP_Term $term. Term to translate field.
	 * @param string $meta_key Meta key.
	 * @param bool $single Single meta value.
	 * @param object WP_Post $language Language.
	 * @param string $fallback Fallback to return if no meta value.
	 * @return string|array
	 *
	 * @from 2.0
	 */
	public function translate_term_meta($term, $meta_key, $single, $language = null, $fallback = null) {

		$translation = $this->get_term_meta_translation($term, $meta_key, $single, $language);

		if ($translation) {

			return $translation;

		} else if (isset($fallback)) {

			return $fallback;

		}

		return get_term_meta($term->term_id, $meta_key, $single);
	}


	/**
	 * find hierarchical post id by path (return post ID not object)
	 *
	 * @param string $page_path Page path.
	 * @param string $post_type Post type.
	 * @return int|null
	 *
	 * @from 2.10
	 */
	public function get_page_by_path($page_path, $post_type = 'page', $language = null) {
    global $wpdb;

    // @from https://developer.wordpress.org/reference/functions/get_page_by_path/
    $page_path     = rawurlencode( urldecode( $page_path ) );
    $page_path     = str_replace( '%2F', '/', $page_path );
    $page_path     = str_replace( '%20', ' ', $page_path );
    $parts         = explode( '/', trim( $page_path, '/' ) );
    $parts         = array_map( 'sanitize_title_for_query', $parts );

    // if ($parts && $this->is_post_type_translatable($post_type) && $this->get_language_by($parts[0], 'post_name')) {
		//
    //   array_shift($parts);
		//
    // }

    $escaped_parts = esc_sql( $parts );
    $in_string = "'" . implode( "','", $escaped_parts ) . "'";

    $post_type = esc_sql($post_type);

    // $language_slugs = $this->get_language_column('post_name');
    // $language_slugs = esc_sql($language_slugs);
    // $language_slugs_in_string = "'" . implode("_post_name','", $post_names) . "_post_name'";

		$prefix = (string) $this->get_prefix($language);
		$prefix = esc_sql($prefix);

    $sql = "SELECT p.ID, p.post_name, p.post_parent, pm.meta_value FROM $wpdb->posts AS p
      LEFT JOIN $wpdb->postmeta AS pm ON (p.ID = pm.post_id)
			WHERE (p.post_name IN ($in_string) || (pm.meta_key = '{$prefix}post_name' AND pm.meta_value IN ($in_string)))
      	AND p.post_type = '$post_type'
      GROUP BY p.ID";

    $pages = $wpdb->get_results($sql);

    $find = function($parts) use ($pages, &$find) {

      $slug = array_pop($parts);

      if (count($parts) > 0) {

        $parent = $find($parts);

        if ($parent) {

          $parent_id = $parent->ID;

        }

      } else {

        $parent_id = 0;

      }

      if ($slug && isset($parent_id)) {

        foreach ($pages as $page ) {

          if ($page->post_parent == $parent_id && ($page->post_name === $slug || $page->meta_value === $slug)) {

            return $page;

          }

        }

      }

    };

    $page = $find($parts);

    if ($page) {

      return $page->ID;

    }

  }

}