search improved based on user feedback: it now includes results that contain word...

[living-lab-site.git] / application / models / videos_model.php

diff --git a/application/models/videos_model.php b/application/models/videos_model.php
index 73bdde7..c8eeb7f 100644 (file)
--- a/application/models/videos_model.php
+++ b/application/models/videos_model.php
@@ -238,21 +238,50 @@ class Videos_model extends CI_Model {
         */
        public function search_videos($search_query, $offset = 0, $count = 0, 
                                                                        $category_id = NULL)
-       {               
-               if (! $this->is_advanced_search_query($search_query)) // if natural language mode
+       {
+               $search_query = trim($search_query);
+               
+               // Search word fragments.
+               // sfc = search fragment condition
+               $sfc = "( ";
+               // sfr = serach fragment relevation
+               $sfr = "( ";
+               $sep = ' +-*<>()~"';
+               $fragm = strtok($search_query, $sep);
+               while ($fragm !== FALSE)
+               {
+                       $sfc .= "(title LIKE '%$fragm%'
+                                       OR description LIKE '%$fragm%'
+                                       OR tags LIKE '%$fragm%') OR ";
+                       
+                       // Frament relevations are half of boolean relevations such
+                       // that they will appear at the end of the results.
+                       $sfr .= "0.25 * (title LIKE '%$fragm%')
+                                       + 0.1 * (description LIKE '%$fragm%')
+                                       + 0.15 * (tags LIKE '%$fragm%') + ";
+                       
+                       $fragm = strtok($sep);
+               }
+               $sfc = substr($sfc, 0, -4) . " )";
+               $sfr = substr($sfr, 0, -3) . " )";
+               
+               if (! $this->is_advanced_search_query($search_query))
                {
                        $search_cond = "MATCH (title, description, tags)
-                                       AGAINST ('$search_query')";
-                       $relevance = "$search_cond AS relevance";
-               }       // if boolean mode
+                                       AGAINST ('$search_query') OR $sfc";
+                       $relevance = "( MATCH (title, description, tags)
+                                       AGAINST ('$search_query') + $sfr ) AS relevance";
+               }
+               // boolean mode
                else
                {
                        $against = "AGAINST ('$search_query' IN BOOLEAN MODE)";
-                       $search_cond = "MATCH (title, description, tags)
-                                       $against";
-                       $relevance = "( (0.5 * (MATCH(title) $against))
-                                       + (0.3 * (MATCH(tags) $against))
-                                       + (0.2 * (MATCH(description) $against)) ) AS relevance";
+                       $search_cond = "( MATCH (title, description, tags)
+                                       $against) OR $sfc";
+                       $relevance = "( 0.5 * (MATCH(title) $against)
+                                       + 0.3 * (MATCH(tags) $against)
+                                       + 0.2 * (MATCH(description) $against)
+                                       + $sfr) AS relevance";
                }
                
                if ($count === 0)
@@ -262,9 +291,10 @@ class Videos_model extends CI_Model {
                        $limit = "";
                }
                else
-               { 
+               {
+                       // TODO select data, description if details are needed
                        $selected_columns = "id, name, title, duration, user_id, views,
-                                       thumbs_count, default_thumb, date, description,
+                                       thumbs_count, default_thumb,
                                        (views + likes - dislikes) AS score, 
                                        $relevance";
                        $order = "ORDER BY relevance DESC, score DESC";
@@ -276,13 +306,12 @@ class Videos_model extends CI_Model {
                else
                        $category_cond = "";
 
-               $search_query = trim($search_query);
-               
                $str_query = "SELECT $selected_columns
                        FROM `videos`
                        WHERE  $category_cond $search_cond
                        $order
                        $limit";
+               //echo "<p>$str_query</p>";
                $query = $this->db->query($str_query);
                
                if ($query->num_rows() > 0)