Changeset 27635

Timestamp:

03/20/2014 02:58:48 AM (11 years ago)

Author:

nacin

Message:

Fix various issues with WP_Adjacent_Post:

• Performance / number of queries.
• Incorrect results caused by sticky posts.
• Back compat for filters, which had used "WHERE" while WP_Query does not; and fixing table references.

props ethitter.
fixes #26937.

Location:

trunk

Files:

• src/wp-includes/link-template.php (modified) (5 diffs)
• tests/phpunit/tests/link.php (modified) (3 diffs)

trunk/src/wp-includes/link-template.php

@@ -1244 +1244 @@
 
     /**
-     * Allow direct access to adjacent post from the class instance itself
+     * Allow direct access to adjacent post from the class instance itself.
      *
      * @param string $property Property to get.
@@ -1274 +1274 @@
      */
     protected function get_post( $args ) {
-        $this->current_post = get_post( $args['post'] );
+        $this->current_post   = get_post( $args['post'] );
         $this->excluded_terms = array_map( 'intval', $args['excluded_terms'] );
         $this->adjacent       = $args['previous'] ? 'previous' : 'next';
@@ -1292 +1292 @@
         // Build our arguments for WP_Query.
         $query_args = array(
-            'posts_per_page'   => 1,
-            'post_status'      => 'publish',
-            'post_type'        => 'post',
-            'orderby'          => 'date',
-            'order'            => 'previous' === $this->adjacent ? 'DESC' : 'ASC',
-            'no_found_rows'    => true,
-            'cache_results'    => true,
-            'date_query'       => array(),
+            'posts_per_page'      => 1,
+            'post_status'         => 'publish',
+            'post_type'           => 'post',
+            'orderby'             => 'date',
+            'order'               => 'previous' === $this->adjacent ? 'DESC' : 'ASC',
+            'ignore_sticky_posts' => true,
+            'date_query'          => array(),
+
+            // Performance considerations:
+            'no_found_rows'          => true,
+            'cache_results'          => true,
+            'update_post_term_cache' => false,
+            'update_post_meta_cache' => false,
+            'split_the_query'        => wp_using_ext_object_cache(),
         );
 
@@ -1389 +1395 @@
         remove_filter( 'posts_clauses', array( $this, 'filter' ) );
 
-        /*
-         * The `join` and `where` filters are identical in their parameters,
-         * so we can use the same approach for both.
+        /**
+         * If no legacy filter callbacks are registered, proceed no further.
          */
-        foreach ( array( 'join', 'where' ) as $clause ) {
-            if ( has_filter( 'get_' . $this->adjacent . '_post_' . $clause ) ) {
-                $clauses[ $clause ] = $this->filter_join_and_where( $clauses[ $clause ], $clause );
-            }
+        if ( ! has_filter( 'get_' . $this->adjacent . '_post_join' ) && ! has_filter( 'get_' . $this->adjacent . '_post_where' ) && ! has_filter( 'get_' . $this->adjacent . '_post_sort' ) ) {
+            return $clauses;
+        }
+
+        /**
+         * Posts table must be aliased as `p` for backwards compatibility with query previously generated by `get_adjacent_post()`.
+         */
+        $clauses = array_map( array( $this, 'alias_posts_table' ), $clauses );
+
+        /**
+         * Apply the legacy `join` filter.
+         */
+        if ( has_filter( 'get_' . $this->adjacent . '_post_join' ) ) {
+            $clauses['join'] = $this->filter_join( $clauses['join'] );
+        }
+
+        /**
+         * Posts table must be aliased as `p` for backwards compatibility with query previously generated by `get_adjacent_post()`.
+         * No filter on the table name exists, so we have to leverage the next applied filter, that for the `join` clause.
+         * We wait to apply this until after the legacy filter is applied so that the legacy filter doesn't remove the alias.
+         */
+        $clauses['join'] = 'AS p ' . $clauses['join'];
+
+        /**
+         * Apply the legacy `where` filter.
+         */
+        if ( has_filter( 'get_' . $this->adjacent . '_post_where' ) ) {
+            $clauses['where'] = $this->filter_where( $clauses['where'] );
         }
 
@@ -1412 +1441 @@
 
     /**
-     * Apply the deprecated `join` or `where` clause filter to the clauses built by WP_Query.
+     * Alias posts table as `p` to match query previously built by `get_adjacent_post()`.
      *
-     * @param string $value
-     * @param string $clause
+     * @global $wpdb
+     * @param string  Clause to alias
      * @return string
      */
-    protected function filter_join_and_where( $value, $clause ) {
+    protected function alias_posts_table( $clause ) {
+        global $wpdb;
+
+        return str_replace( $wpdb->posts, 'p', $clause );
+    }
+
+    /**
+     * Apply the deprecated `join` clause filter to the clause built by WP_Query.
+     *
+     * @param string $join
+     * @return string
+     */
+    protected function filter_join( $join ) {
         /**
-         * @todo Minimal hook docs
          * @deprecated 3.9.0
          */
-        return apply_filters( 'get_' . $this->adjacent . '_post_' . $clause, $value, $this->in_same_term, $this->excluded_terms );
+        return apply_filters( 'get_' . $this->adjacent . '_post_join', $join, $this->in_same_term, $this->excluded_terms );
+    }
+
+    /**
+     * Apply the deprecated `where` clause filter to the clause built by WP_Query.
+     *
+     * @param string $join
+     * @return string
+     */
+    protected function filter_where( $where ) {
+        $where = trim( $where );
+
+        // The legacy filter passed the entire clause, including the `WHERE`, while WP_Query's filter does not.
+        // We prepend the `WHERE` for the benefit of legacy callbacks that look for it.
+        if ( 0 !== stripos( $where, 'where' ) ) {
+            $where = 'WHERE 1=1 ' . $where;
+        }
+
+        /**
+         * @deprecated 3.9.0
+         */
+        $where = apply_filters( 'get_' . $this->adjacent . '_post_where', $where, $this->in_same_term, $this->excluded_terms );
+
+        $where = trim( $where );
+
+        // The legacy filter passed the entire clause, including the `WHERE`, while WP_Query's filter does not.
+        // Removing the `WHERE` is necessary as we've added it above, and the legacy filter could include it in the returned string.
+        if ( 0 === stripos( $where, 'where 1=1' ) ) {
+            $where = substr( $where, 9 );
+        } elseif ( 0 === stripos( $where, 'where' ) ) {
+            $where = substr( $where, 5 );
+        }
+
+        $where = trim( $where );
+
+        // WP_Query expects that the string returned begins with `AND`, as it is prepended with "1=1" when the clauses are joined
+        if ( 0 !== stripos( $where, 'and' ) ) {
+            $where = 'AND ' . $where;
+        }
+
+        return $where;
     }
 

trunk/tests/phpunit/tests/link.php

@@ -209 +209 @@
         remove_filter( 'get_next_post_where', array( $this, 'filter_next_post_where' ) );
 
+        // Test "where" filter that writes its own query
+        add_filter( 'get_previous_post_where', array( $this, 'override_previous_post_where_clause' ) );
+        $this->go_to( get_permalink( $post_four->ID ) );
+        $this->assertEquals( $post_two, get_adjacent_post( false, null, true ) );
+        remove_filter( 'get_previous_post_where', array( $this, 'override_previous_post_where_clause' ) );
+
         // Test "join" filter by joining the postmeta table and restricting by meta key
         add_filter( 'get_next_post_join', array( $this, 'filter_next_post_join' ) );
@@ -249 +255 @@
      * Filter callback for `test_legacy_get_adjacent_post_filters()`
      */
+    function override_previous_post_where_clause( $where ) {
+        $where = "WHERE p.post_date < '2012-02-28'";
+        return $where;
+    }
+
+    /**
+     * Filter callback for `test_legacy_get_adjacent_post_filters()`
+     */
     function filter_next_post_join( $join ) {
         global $wpdb;
 
-        $join .= " INNER JOIN {$wpdb->postmeta} ON {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id";
+        $join .= " INNER JOIN {$wpdb->postmeta} ON p.ID = {$wpdb->postmeta}.post_id";
         return $join;
     }
@@ -270 +284 @@
      */
     function filter_next_post_sort( $sort ) {
-        global $wpdb;
-
-        $sort = str_replace( $wpdb->posts . '.post_date', $wpdb->posts . '.post_title', $sort );
-        return $sort;
+        return str_replace( 'p.post_date', 'p.post_title', $sort );
     }