]> scripts.mit.edu Git - autoinstalls/wordpress.git/blobdiff - wp-includes/class-wp-tax-query.php
WordPress 4.4
[autoinstalls/wordpress.git] / wp-includes / class-wp-tax-query.php
diff --git a/wp-includes/class-wp-tax-query.php b/wp-includes/class-wp-tax-query.php
new file mode 100644 (file)
index 0000000..356b692
--- /dev/null
@@ -0,0 +1,665 @@
+<?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 {@see WP_Tax_Query::__construct()} for information on tax query arguments.
+        *
+        * @since 3.1.0
+        * @access public
+        * @var array
+        */
+       public $queries = array();
+
+       /**
+        * The relation between the queries. Can be one of 'AND' or 'OR'.
+        *
+        * @since 3.1.0
+        * @access public
+        * @var string
+        */
+       public $relation;
+
+       /**
+        * Standard response when the query should not return any rows.
+        *
+        * @since 3.2.0
+        *
+        * @static
+        * @access private
+        * @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
+        * @access protected
+        * @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
+        * @access public
+        * @var array
+        */
+       public $queried_terms = array();
+
+       /**
+        * Database table that where the metadata's objects are stored (eg $wpdb->users).
+        *
+        * @since 4.1.0
+        * @access public
+        * @var string
+        */
+       public $primary_table;
+
+       /**
+        * Column in 'primary_table' that represents the ID of the object.
+        *
+        * @since 4.1.0
+        * @access public
+        * @var string
+        */
+       public $primary_id_column;
+
+       /**
+        * Constructor.
+        *
+        * @since 3.1.0
+        * @since 4.1.0 Added support for `$operator` 'NOT EXISTS' and 'EXISTS' values.
+        * @access public
+        *
+        * @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
+        * @access public
+        *
+        * @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
+        * @access public
+        *
+        * @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
+        * @access protected
+        *
+        * @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
+        * @access public
+        *
+        * @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
+        * @access protected
+        *
+        * @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
+        * @access protected
+        *
+        * @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
+        * @access public
+        *
+        * @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 .= " INNER 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
+        * @access protected
+        *
+        * @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 $alias;
+       }
+
+       /**
+        * Validates a single query.
+        *
+        * @since 3.2.0
+        * @access private
+        *
+        * @param array &$query The single query.
+        */
+       private function clean_query( &$query ) {
+               if ( empty( $query['taxonomy'] ) ) {
+                       if ( 'term_taxonomy_id' !== $query['field'] ) {
+                               $query = new WP_Error( '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' );
+                       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.
+        *
+        * @since 3.2.0
+        *
+        * @global wpdb $wpdb The WordPress database abstraction object.
+        *
+        * @param array  &$query          The single query.
+        * @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 ) {
+               global $wpdb;
+
+               if ( empty( $query['terms'] ) )
+                       return;
+
+               if ( $query['field'] == $resulting_field )
+                       return;
+
+               $resulting_field = sanitize_key( $resulting_field );
+
+               switch ( $query['field'] ) {
+                       case 'slug':
+                       case 'name':
+                               foreach ( $query['terms'] as &$term ) {
+                                       /*
+                                        * 0 is the $term_id parameter. We don't have a term ID yet, but it doesn't
+                                        * matter because `sanitize_term_field()` ignores the $term_id param when the
+                                        * context is 'db'.
+                                        */
+                                       $term = "'" . esc_sql( sanitize_term_field( $query['field'], $term, 0, $query['taxonomy'], 'db' ) ) . "'";
+                               }
+
+                               $terms = implode( ",", $query['terms'] );
+
+                               $terms = $wpdb->get_col( "
+                                       SELECT $wpdb->term_taxonomy.$resulting_field
+                                       FROM $wpdb->term_taxonomy
+                                       INNER JOIN $wpdb->terms USING (term_id)
+                                       WHERE taxonomy = '{$query['taxonomy']}'
+                                       AND $wpdb->terms.{$query['field']} IN ($terms)
+                               " );
+                               break;
+                       case 'term_taxonomy_id':
+                               $terms = implode( ',', array_map( 'intval', $query['terms'] ) );
+                               $terms = $wpdb->get_col( "
+                                       SELECT $resulting_field
+                                       FROM $wpdb->term_taxonomy
+                                       WHERE term_taxonomy_id IN ($terms)
+                               " );
+                               break;
+                       default:
+                               $terms = implode( ',', array_map( 'intval', $query['terms'] ) );
+                               $terms = $wpdb->get_col( "
+                                       SELECT $resulting_field
+                                       FROM $wpdb->term_taxonomy
+                                       WHERE taxonomy = '{$query['taxonomy']}'
+                                       AND term_id IN ($terms)
+                               " );
+               }
+
+               if ( 'AND' == $query['operator'] && count( $terms ) < count( $query['terms'] ) ) {
+                       $query = new WP_Error( 'Inexistent terms' );
+                       return;
+               }
+
+               $query['terms'] = $terms;
+               $query['field'] = $resulting_field;
+       }
+}