wp/wp-includes/class-wp-tax-query.php
changeset 7 cf61fcea0001
child 9 177826044cd9
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-tax-query.php	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,649 @@
+<?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
+ */
+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
+	 *
+	 * @static
+	 * @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 {
+	 *         Optional. 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( $tax_query );
+	}
+
+	/**
+	 * Ensure the 'tax_query' argument passed to the class constructor is well-formed.
+	 *
+	 * Ensures that each query-level clause has a 'relation' key, and that
+	 * each first-order clause contains all the necessary keys from `$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;
+	}
+
+	/**
+	 * Sanitize 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';
+		}
+	}
+
+	/**
+	 * Determine 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
+	 *
+	 * @static
+	 *
+	 * @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
+	 *
+	 * @static
+	 *
+	 * @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 array {
+	 *     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();
+	}
+
+	/**
+	 * Generate 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 array {
+	 *     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;
+	}
+
+	/**
+	 * Generate 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 array {
+	 *     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;
+	}
+
+	/**
+	 * Generate 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  SQL fragment to append to the main JOIN clause.
+	 *     @type string $where SQL fragment to append to the main WHERE clause.
+	 * }
+	 */
+	public function get_sql_for_clause( &$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 $sql;
+	}
+
+	/**
+	 * Identify an existing table alias that is compatible with the current query clause.
+	 *
+	 * We avoid unnecessary table joins by allowing each clause to look for
+	 * an existing table alias that is compatible with the query that it
+	 * needs to perform.
+	 *
+	 * An existing alias is compatible if (a) it is a sibling of `$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 ) ) {
+				$alias = $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;
+		}
+
+		$query['terms'] = array_unique( (array) $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
+	 *
+	 * @global wpdb $wpdb The WordPress database abstraction object.
+	 *
+	 * @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;
+		}
+
+		$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;
+	}
+}