Add a plugin that sorts search results for API sites based on title, then excerpt, then content. Exact title matches come first.

Author: nacin

mu-plugins/api-sites/search-weights.php

@@ -0,0 +1,41 @@
+<?php
+/**
+ * Sorts unpaginated search results more intutiviely.
+ *
+ * If the search terms exactly match an item's title, that item is first. Then, general
+ * matches occur on the title, excerpt, and content fields, sorted in that order.
+ */
+
+add_filter( 'the_posts', function( $posts, $query ) {
+	if ( ! $query->is_main_query() || ! $query->is_search() )
+		return $posts;
+
+	$priorities = array_fill( 0, 4, array() );
+
+	$search_terms = $query->query_vars['search_terms'];
+	$search_terms = array_map( 'strtolower', $search_terms );
+	foreach ( $posts as $post ) {
+		if ( strtolower( $post->post_title ) === implode( ' ', $search_terms ) ) {
+			// Perfect title match: Priority 0.
+			$priorities[0][] = $post;
+			continue;
+		}
+
+		foreach ( array( 1 => 'post_title', 2 => 'post_excerpt' ) as $priority => $field ) {
+			foreach ( $search_terms as $search_term ) {
+				// A search term is not present in the field, so move to the next field.
+				if ( false === stripos( $post->$field, $search_term ) )
+					continue 2;
+			}
+
+			// Found all matching terms in this field, so add it to the respective priority.
+			$priorities[ $priority ][] = $post;
+			continue 2;
+		}
+
+		// No matches in a priority field, so assume the post got here via the content.
+		$priorities[3][] = $post;
+	}
+
+	return array_merge( $priorities[0], $priorities[1], $priorities[2], $priorities[3] );
+}, 10, 2 );