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Diffstat (limited to 'wp-includes/class-wp-tax-query.php')
| -rw-r--r-- | wp-includes/class-wp-tax-query.php | 659 |
1 files changed, 659 insertions, 0 deletions
diff --git a/wp-includes/class-wp-tax-query.php b/wp-includes/class-wp-tax-query.php new file mode 100644 index 0000000..38841c4 --- /dev/null +++ b/wp-includes/class-wp-tax-query.php @@ -0,0 +1,659 @@ +<?php +/** + * Taxonomy API: WP_Tax_Query class + * + * @package WordPress + * @subpackage Taxonomy + * @since 4.4.0 + */ + +/** + * Core class used to implement taxonomy queries for the Taxonomy API. + * + * Used for generating SQL clauses that filter a primary query according to object + * taxonomy terms. + * + * WP_Tax_Query is a helper that allows primary query classes, such as WP_Query, to filter + * their results by object metadata, by generating `JOIN` and `WHERE` subclauses to be + * attached to the primary SQL query string. + * + * @since 3.1.0 + */ +#[AllowDynamicProperties] +class WP_Tax_Query { + + /** + * Array of taxonomy queries. + * + * See WP_Tax_Query::__construct() for information on tax query arguments. + * + * @since 3.1.0 + * @var array + */ + public $queries = array(); + + /** + * The relation between the queries. Can be one of 'AND' or 'OR'. + * + * @since 3.1.0 + * @var string + */ + public $relation; + + /** + * Standard response when the query should not return any rows. + * + * @since 3.2.0 + * @var string + */ + private static $no_results = array( + 'join' => array( '' ), + 'where' => array( '0 = 1' ), + ); + + /** + * A flat list of table aliases used in the JOIN clauses. + * + * @since 4.1.0 + * @var array + */ + protected $table_aliases = array(); + + /** + * Terms and taxonomies fetched by this query. + * + * We store this data in a flat array because they are referenced in a + * number of places by WP_Query. + * + * @since 4.1.0 + * @var array + */ + public $queried_terms = array(); + + /** + * Database table that where the metadata's objects are stored (eg $wpdb->users). + * + * @since 4.1.0 + * @var string + */ + public $primary_table; + + /** + * Column in 'primary_table' that represents the ID of the object. + * + * @since 4.1.0 + * @var string + */ + public $primary_id_column; + + /** + * Constructor. + * + * @since 3.1.0 + * @since 4.1.0 Added support for `$operator` 'NOT EXISTS' and 'EXISTS' values. + * + * @param array $tax_query { + * Array of taxonomy query clauses. + * + * @type string $relation Optional. The MySQL keyword used to join + * the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'. + * @type array ...$0 { + * An array of first-order clause parameters, or another fully-formed tax query. + * + * @type string $taxonomy Taxonomy being queried. Optional when field=term_taxonomy_id. + * @type string|int|array $terms Term or terms to filter by. + * @type string $field Field to match $terms against. Accepts 'term_id', 'slug', + * 'name', or 'term_taxonomy_id'. Default: 'term_id'. + * @type string $operator MySQL operator to be used with $terms in the WHERE clause. + * Accepts 'AND', 'IN', 'NOT IN', 'EXISTS', 'NOT EXISTS'. + * Default: 'IN'. + * @type bool $include_children Optional. Whether to include child terms. + * Requires a $taxonomy. Default: true. + * } + * } + */ + public function __construct( $tax_query ) { + if ( isset( $tax_query['relation'] ) ) { + $this->relation = $this->sanitize_relation( $tax_query['relation'] ); + } else { + $this->relation = 'AND'; + } + + $this->queries = $this->sanitize_query( $tax_query ); + } + + /** + * Ensures the 'tax_query' argument passed to the class constructor is well-formed. + * + * Ensures that each query-level clause has a 'relation' key, and that + * each first-order clause contains all the necessary keys from `$defaults`. + * + * @since 4.1.0 + * + * @param array $queries Array of queries clauses. + * @return array Sanitized array of query clauses. + */ + public function sanitize_query( $queries ) { + $cleaned_query = array(); + + $defaults = array( + 'taxonomy' => '', + 'terms' => array(), + 'field' => 'term_id', + 'operator' => 'IN', + 'include_children' => true, + ); + + foreach ( $queries as $key => $query ) { + if ( 'relation' === $key ) { + $cleaned_query['relation'] = $this->sanitize_relation( $query ); + + // First-order clause. + } elseif ( self::is_first_order_clause( $query ) ) { + + $cleaned_clause = array_merge( $defaults, $query ); + $cleaned_clause['terms'] = (array) $cleaned_clause['terms']; + $cleaned_query[] = $cleaned_clause; + + /* + * Keep a copy of the clause in the flate + * $queried_terms array, for use in WP_Query. + */ + if ( ! empty( $cleaned_clause['taxonomy'] ) && 'NOT IN' !== $cleaned_clause['operator'] ) { + $taxonomy = $cleaned_clause['taxonomy']; + if ( ! isset( $this->queried_terms[ $taxonomy ] ) ) { + $this->queried_terms[ $taxonomy ] = array(); + } + + /* + * Backward compatibility: Only store the first + * 'terms' and 'field' found for a given taxonomy. + */ + if ( ! empty( $cleaned_clause['terms'] ) && ! isset( $this->queried_terms[ $taxonomy ]['terms'] ) ) { + $this->queried_terms[ $taxonomy ]['terms'] = $cleaned_clause['terms']; + } + + if ( ! empty( $cleaned_clause['field'] ) && ! isset( $this->queried_terms[ $taxonomy ]['field'] ) ) { + $this->queried_terms[ $taxonomy ]['field'] = $cleaned_clause['field']; + } + } + + // Otherwise, it's a nested query, so we recurse. + } elseif ( is_array( $query ) ) { + $cleaned_subquery = $this->sanitize_query( $query ); + + if ( ! empty( $cleaned_subquery ) ) { + // All queries with children must have a relation. + if ( ! isset( $cleaned_subquery['relation'] ) ) { + $cleaned_subquery['relation'] = 'AND'; + } + + $cleaned_query[] = $cleaned_subquery; + } + } + } + + return $cleaned_query; + } + + /** + * Sanitizes a 'relation' operator. + * + * @since 4.1.0 + * + * @param string $relation Raw relation key from the query argument. + * @return string Sanitized relation ('AND' or 'OR'). + */ + public function sanitize_relation( $relation ) { + if ( 'OR' === strtoupper( $relation ) ) { + return 'OR'; + } else { + return 'AND'; + } + } + + /** + * Determines whether a clause is first-order. + * + * A "first-order" clause is one that contains any of the first-order + * clause keys ('terms', 'taxonomy', 'include_children', 'field', + * 'operator'). An empty clause also counts as a first-order clause, + * for backward compatibility. Any clause that doesn't meet this is + * determined, by process of elimination, to be a higher-order query. + * + * @since 4.1.0 + * + * @param array $query Tax query arguments. + * @return bool Whether the query clause is a first-order clause. + */ + protected static function is_first_order_clause( $query ) { + return is_array( $query ) && ( empty( $query ) || array_key_exists( 'terms', $query ) || array_key_exists( 'taxonomy', $query ) || array_key_exists( 'include_children', $query ) || array_key_exists( 'field', $query ) || array_key_exists( 'operator', $query ) ); + } + + /** + * Generates SQL clauses to be appended to a main query. + * + * @since 3.1.0 + * + * @param string $primary_table Database table where the object being filtered is stored (eg wp_users). + * @param string $primary_id_column ID column for the filtered object in $primary_table. + * @return string[] { + * Array containing JOIN and WHERE SQL clauses to append to the main query. + * + * @type string $join SQL fragment to append to the main JOIN clause. + * @type string $where SQL fragment to append to the main WHERE clause. + * } + */ + public function get_sql( $primary_table, $primary_id_column ) { + $this->primary_table = $primary_table; + $this->primary_id_column = $primary_id_column; + + return $this->get_sql_clauses(); + } + + /** + * Generates SQL clauses to be appended to a main query. + * + * Called by the public WP_Tax_Query::get_sql(), this method + * is abstracted out to maintain parity with the other Query classes. + * + * @since 4.1.0 + * + * @return string[] { + * Array containing JOIN and WHERE SQL clauses to append to the main query. + * + * @type string $join SQL fragment to append to the main JOIN clause. + * @type string $where SQL fragment to append to the main WHERE clause. + * } + */ + protected function get_sql_clauses() { + /* + * $queries are passed by reference to get_sql_for_query() for recursion. + * To keep $this->queries unaltered, pass a copy. + */ + $queries = $this->queries; + $sql = $this->get_sql_for_query( $queries ); + + if ( ! empty( $sql['where'] ) ) { + $sql['where'] = ' AND ' . $sql['where']; + } + + return $sql; + } + + /** + * Generates SQL clauses for a single query array. + * + * If nested subqueries are found, this method recurses the tree to + * produce the properly nested SQL. + * + * @since 4.1.0 + * + * @param array $query Query to parse (passed by reference). + * @param int $depth Optional. Number of tree levels deep we currently are. + * Used to calculate indentation. Default 0. + * @return string[] { + * Array containing JOIN and WHERE SQL clauses to append to a single query array. + * + * @type string $join SQL fragment to append to the main JOIN clause. + * @type string $where SQL fragment to append to the main WHERE clause. + * } + */ + protected function get_sql_for_query( &$query, $depth = 0 ) { + $sql_chunks = array( + 'join' => array(), + 'where' => array(), + ); + + $sql = array( + 'join' => '', + 'where' => '', + ); + + $indent = ''; + for ( $i = 0; $i < $depth; $i++ ) { + $indent .= ' '; + } + + foreach ( $query as $key => &$clause ) { + if ( 'relation' === $key ) { + $relation = $query['relation']; + } elseif ( is_array( $clause ) ) { + + // This is a first-order clause. + if ( $this->is_first_order_clause( $clause ) ) { + $clause_sql = $this->get_sql_for_clause( $clause, $query ); + + $where_count = count( $clause_sql['where'] ); + if ( ! $where_count ) { + $sql_chunks['where'][] = ''; + } elseif ( 1 === $where_count ) { + $sql_chunks['where'][] = $clause_sql['where'][0]; + } else { + $sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )'; + } + + $sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] ); + // This is a subquery, so we recurse. + } else { + $clause_sql = $this->get_sql_for_query( $clause, $depth + 1 ); + + $sql_chunks['where'][] = $clause_sql['where']; + $sql_chunks['join'][] = $clause_sql['join']; + } + } + } + + // Filter to remove empties. + $sql_chunks['join'] = array_filter( $sql_chunks['join'] ); + $sql_chunks['where'] = array_filter( $sql_chunks['where'] ); + + if ( empty( $relation ) ) { + $relation = 'AND'; + } + + // Filter duplicate JOIN clauses and combine into a single string. + if ( ! empty( $sql_chunks['join'] ) ) { + $sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) ); + } + + // Generate a single WHERE clause with proper brackets and indentation. + if ( ! empty( $sql_chunks['where'] ) ) { + $sql['where'] = '( ' . "\n " . $indent . implode( ' ' . "\n " . $indent . $relation . ' ' . "\n " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')'; + } + + return $sql; + } + + /** + * Generates SQL JOIN and WHERE clauses for a "first-order" query clause. + * + * @since 4.1.0 + * + * @global wpdb $wpdb The WordPress database abstraction object. + * + * @param array $clause Query clause (passed by reference). + * @param array $parent_query Parent query array. + * @return array { + * Array containing JOIN and WHERE SQL clauses to append to a first-order query. + * + * @type string[] $join Array of SQL fragments to append to the main JOIN clause. + * @type string[] $where Array of SQL fragments to append to the main WHERE clause. + * } + */ + public function get_sql_for_clause( &$clause, $parent_query ) { + global $wpdb; + + $sql = array( + 'where' => array(), + 'join' => array(), + ); + + $join = ''; + $where = ''; + + $this->clean_query( $clause ); + + if ( is_wp_error( $clause ) ) { + return self::$no_results; + } + + $terms = $clause['terms']; + $operator = strtoupper( $clause['operator'] ); + + if ( 'IN' === $operator ) { + + if ( empty( $terms ) ) { + return self::$no_results; + } + + $terms = implode( ',', $terms ); + + /* + * Before creating another table join, see if this clause has a + * sibling with an existing join that can be shared. + */ + $alias = $this->find_compatible_table_alias( $clause, $parent_query ); + if ( false === $alias ) { + $i = count( $this->table_aliases ); + $alias = $i ? 'tt' . $i : $wpdb->term_relationships; + + // Store the alias as part of a flat array to build future iterators. + $this->table_aliases[] = $alias; + + // Store the alias with this clause, so later siblings can use it. + $clause['alias'] = $alias; + + $join .= " LEFT JOIN $wpdb->term_relationships"; + $join .= $i ? " AS $alias" : ''; + $join .= " ON ($this->primary_table.$this->primary_id_column = $alias.object_id)"; + } + + $where = "$alias.term_taxonomy_id $operator ($terms)"; + + } elseif ( 'NOT IN' === $operator ) { + + if ( empty( $terms ) ) { + return $sql; + } + + $terms = implode( ',', $terms ); + + $where = "$this->primary_table.$this->primary_id_column NOT IN ( + SELECT object_id + FROM $wpdb->term_relationships + WHERE term_taxonomy_id IN ($terms) + )"; + + } elseif ( 'AND' === $operator ) { + + if ( empty( $terms ) ) { + return $sql; + } + + $num_terms = count( $terms ); + + $terms = implode( ',', $terms ); + + $where = "( + SELECT COUNT(1) + FROM $wpdb->term_relationships + WHERE term_taxonomy_id IN ($terms) + AND object_id = $this->primary_table.$this->primary_id_column + ) = $num_terms"; + + } elseif ( 'NOT EXISTS' === $operator || 'EXISTS' === $operator ) { + + $where = $wpdb->prepare( + "$operator ( + SELECT 1 + FROM $wpdb->term_relationships + INNER JOIN $wpdb->term_taxonomy + ON $wpdb->term_taxonomy.term_taxonomy_id = $wpdb->term_relationships.term_taxonomy_id + WHERE $wpdb->term_taxonomy.taxonomy = %s + AND $wpdb->term_relationships.object_id = $this->primary_table.$this->primary_id_column + )", + $clause['taxonomy'] + ); + + } + + $sql['join'][] = $join; + $sql['where'][] = $where; + return $sql; + } + + /** + * Identifies an existing table alias that is compatible with the current query clause. + * + * We avoid unnecessary table joins by allowing each clause to look for + * an existing table alias that is compatible with the query that it + * needs to perform. + * + * An existing alias is compatible if (a) it is a sibling of `$clause` + * (ie, it's under the scope of the same relation), and (b) the combination + * of operator and relation between the clauses allows for a shared table + * join. In the case of WP_Tax_Query, this only applies to 'IN' + * clauses that are connected by the relation 'OR'. + * + * @since 4.1.0 + * + * @param array $clause Query clause. + * @param array $parent_query Parent query of $clause. + * @return string|false Table alias if found, otherwise false. + */ + protected function find_compatible_table_alias( $clause, $parent_query ) { + $alias = false; + + // Sanity check. Only IN queries use the JOIN syntax. + if ( ! isset( $clause['operator'] ) || 'IN' !== $clause['operator'] ) { + return $alias; + } + + // Since we're only checking IN queries, we're only concerned with OR relations. + if ( ! isset( $parent_query['relation'] ) || 'OR' !== $parent_query['relation'] ) { + return $alias; + } + + $compatible_operators = array( 'IN' ); + + foreach ( $parent_query as $sibling ) { + if ( ! is_array( $sibling ) || ! $this->is_first_order_clause( $sibling ) ) { + continue; + } + + if ( empty( $sibling['alias'] ) || empty( $sibling['operator'] ) ) { + continue; + } + + // The sibling must both have compatible operator to share its alias. + if ( in_array( strtoupper( $sibling['operator'] ), $compatible_operators, true ) ) { + $alias = preg_replace( '/\W/', '_', $sibling['alias'] ); + break; + } + } + + return $alias; + } + + /** + * Validates a single query. + * + * @since 3.2.0 + * + * @param array $query The single query. Passed by reference. + */ + private function clean_query( &$query ) { + if ( empty( $query['taxonomy'] ) ) { + if ( 'term_taxonomy_id' !== $query['field'] ) { + $query = new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) ); + return; + } + + // So long as there are shared terms, 'include_children' requires that a taxonomy is set. + $query['include_children'] = false; + } elseif ( ! taxonomy_exists( $query['taxonomy'] ) ) { + $query = new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) ); + return; + } + + if ( 'slug' === $query['field'] || 'name' === $query['field'] ) { + $query['terms'] = array_unique( (array) $query['terms'] ); + } else { + $query['terms'] = wp_parse_id_list( $query['terms'] ); + } + + if ( is_taxonomy_hierarchical( $query['taxonomy'] ) && $query['include_children'] ) { + $this->transform_query( $query, 'term_id' ); + + if ( is_wp_error( $query ) ) { + return; + } + + $children = array(); + foreach ( $query['terms'] as $term ) { + $children = array_merge( $children, get_term_children( $term, $query['taxonomy'] ) ); + $children[] = $term; + } + $query['terms'] = $children; + } + + $this->transform_query( $query, 'term_taxonomy_id' ); + } + + /** + * Transforms a single query, from one field to another. + * + * Operates on the `$query` object by reference. In the case of error, + * `$query` is converted to a WP_Error object. + * + * @since 3.2.0 + * + * @param array $query The single query. Passed by reference. + * @param string $resulting_field The resulting field. Accepts 'slug', 'name', 'term_taxonomy_id', + * or 'term_id'. Default 'term_id'. + */ + public function transform_query( &$query, $resulting_field ) { + if ( empty( $query['terms'] ) ) { + return; + } + + if ( $query['field'] === $resulting_field ) { + return; + } + + $resulting_field = sanitize_key( $resulting_field ); + + // Empty 'terms' always results in a null transformation. + $terms = array_filter( $query['terms'] ); + if ( empty( $terms ) ) { + $query['terms'] = array(); + $query['field'] = $resulting_field; + return; + } + + $args = array( + 'get' => 'all', + 'number' => 0, + 'taxonomy' => $query['taxonomy'], + 'update_term_meta_cache' => false, + 'orderby' => 'none', + ); + + // Term query parameter name depends on the 'field' being searched on. + switch ( $query['field'] ) { + case 'slug': + $args['slug'] = $terms; + break; + case 'name': + $args['name'] = $terms; + break; + case 'term_taxonomy_id': + $args['term_taxonomy_id'] = $terms; + break; + default: + $args['include'] = wp_parse_id_list( $terms ); + break; + } + + if ( ! is_taxonomy_hierarchical( $query['taxonomy'] ) ) { + $args['number'] = count( $terms ); + } + + $term_query = new WP_Term_Query(); + $term_list = $term_query->query( $args ); + + if ( is_wp_error( $term_list ) ) { + $query = $term_list; + return; + } + + if ( 'AND' === $query['operator'] && count( $term_list ) < count( $query['terms'] ) ) { + $query = new WP_Error( 'inexistent_terms', __( 'Inexistent terms.' ) ); + return; + } + + $query['terms'] = wp_list_pluck( $term_list, $resulting_field ); + $query['field'] = $resulting_field; + } +} |