Changeset 2938

Timestamp:

04/12/2016 09:38:46 PM (9 years ago)

Author:

coffee2code

Message:

developer.wordpress.org: Improve ordering of search results by title relevance.

• Show shortest full matches first.
• Convert spaces to underscores when doing title searches for short phrases.

Props keesiemeijer.
Fixes #1516.

File:

• sites/trunk/wordpress.org/public_html/wp-content/themes/pub/wporg-developer/functions.php (modified) (3 diffs)

sites/trunk/wordpress.org/public_html/wp-content/themes/pub/wporg-developer/functions.php

@@ -98 +98 @@
     add_filter( 'post_type_link', __NAMESPACE__ . '\\method_permalink', 10, 2 );
     add_filter( 'term_link', __NAMESPACE__ . '\\taxonomy_permalink', 10, 3 );
+    add_filter( 'posts_orderby', __NAMESPACE__ . '\\search_posts_orderby', 10, 2 );
     add_filter( 'the_posts', __NAMESPACE__ . '\\rerun_empty_exact_search', 10, 2 );
 
@@ -203 +204 @@
     if ( $query->is_search() ) {
 
-        // Order searches by title first.
-        $query->set( 'orderby', '' );
-        $query->set( 'search_orderby_title', 1 );
-
         // If user has '()' at end of a search string, assume they want a specific function/method.
         $s = htmlentities( $query->get( 's' ) );
@@ -221 +218 @@
 
 /**
+ * Filter the SQL for the ORDER BY clause for search queries.
+ *
+ * Adds ORDER BY condition with spaces replaced with underscores in 'post_title'.
+ * Adds ORDER BY condition to order by title length.
+ *
+ * @param string   $orderby The ORDER BY clause of the query.
+ * @param WP_Query $query   The WP_Query instance (passed by reference).
+ * @return string  Filtered order by clause
+ */
+function search_posts_orderby( $orderby, $query ) {
+    global $wpdb;
+
+    if ( $query->is_main_query() && is_search() && ! $query->get( 'exact' ) ) {
+
+        $search_order_by_title = $query->get( 'search_orderby_title' );
+
+        // Check if search_orderby_title is set by WP_Query::parse_search.
+        if ( is_array( $search_order_by_title ) && $search_order_by_title ) {
+
+            // Get search orderby query.
+            $orderby = parse_search_order( $query->query_vars );
+
+            // Add order by title length.
+            $orderby .= " , CHAR_LENGTH( $wpdb->posts.post_title ) ASC, $wpdb->posts.post_title ASC";
+        }
+    }
+
+    return $orderby;
+}
+
+/**
+ * Generate SQL for the ORDER BY condition based on passed search terms.
+ *
+ * Similar to WP_Query::parse_search_order.
+ * Adds ORDER BY condition with spaces replaced with underscores in 'post_title'.
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array   $q Query variables.
+ * @return string ORDER BY clause.
+ */
+function parse_search_order( $q ) {
+    global $wpdb;
+
+    if ( $q['search_terms_count'] > 1 ) {
+        $num_terms = count( $q['search_orderby_title'] );
+
+        // If the search terms contain negative queries, don't bother ordering by sentence matches.
+        $like = $_like = '';
+        if ( ! preg_match( '/(?:\s|^)\-/', $q['s'] ) ) {
+            $like = '%' . $wpdb->esc_like( $q['s'] ) . '%';
+        }
+
+        $search_orderby = '';
+
+        // Sentence match in 'post_title'.
+        if ( $like ) {
+            $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_title LIKE %s THEN 1 ", $like );
+            $_like =  str_replace( '-', '_', sanitize_title_with_dashes( $q['s'] ) );
+            $_like = '%' . $wpdb->esc_like( $_like ) . '%';
+            if ( $_like !== $like ) {
+                // Sentence match in 'post_title' with spaces replaced with underscores.
+                $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_title LIKE %s THEN 2 ", $_like );
+            }
+        }
+
+        // Sanity limit, sort as sentence when more than 6 terms.
+        // (few searches are longer than 6 terms and most titles are not)
+        if ( $num_terms < 7 ) {
+            // all words in title
+            $search_orderby .= 'WHEN ' . implode( ' AND ', $q['search_orderby_title'] ) . ' THEN 3 ';
+            // any word in title, not needed when $num_terms == 1
+            if ( $num_terms > 1 )
+                $search_orderby .= 'WHEN ' . implode( ' OR ', $q['search_orderby_title'] ) . ' THEN 4 ';
+        }
+
+        // Sentence match in 'post_content'.
+        if ( $like ) {
+            $search_orderby .= $wpdb->prepare( "WHEN $wpdb->posts.post_content LIKE %s THEN 5 ", $like );
+        }
+
+        if ( $search_orderby ) {
+            $search_orderby = '(CASE ' . $search_orderby . 'ELSE 6 END)';
+        }
+    } else {
+        // Single word or sentence search.
+        $search_orderby = reset( $q['search_orderby_title'] ) . ' DESC';
+    }
+
+    return $search_orderby;
+}
+
+/**
  * Rerun an exact search with the same criteria except exactness if no posts
  * were found.