Use a weighted search

src/Query.php

@@ -75,6 +75,8 @@
  * @method string[] getFields( array $default = null )
  * @method array getSort( array $default = null )
  * @method bool getUnion( bool $default = null )
+ * @method bool getWeightedSearch( bool $default = null )
+ * @method array getWeightedFields( int[] $default = null )
  * @method AbstractFilterBase getFilter(AbstractFilterBase $default = null ) retrieves condition to be met by resulting documents
  * @method Set getFacet( Set $default = null )
  * @method $this setStart( int $offset )
@@ -86,6 +88,8 @@
  * @method $this setFacet( Set $facet )
  * @method $this addFields( string $fields )
  * @method $this addSort( $sorting )
+ * @method $this setWeightedSearch( bool $isWeightedSearch )
+ * @method $this setWeightedFields( int[] $weightedFields ) assigns boost factors to fields (e.g. [ 'title' => 10, 'abstract' => 0.5 ])
  */
 class Query
 {
@@ -95,14 +99,16 @@ class Query
     public function reset()
     {
         $this->data = [
-            'start'      => null,
-            'rows'       => null,
-            'fields'     => null,
-            'sort'       => null,
-            'union'      => null,
-            'filter'     => null,
-            'facet'      => null,
-            'subfilters' => null,
+            'start'          => null,
+            'rows'           => null,
+            'fields'         => null,
+            'sort'           => null,
+            'union'          => null,
+            'filter'         => null,
+            'facet'          => null,
+            'subfilters'     => null,
+            'weightedsearch' => null,
+            'weightedfields' => null,
         ];
     }
 
@@ -267,6 +273,7 @@ public function set($name, $value, $adding = false)
                 break;
 
             case 'union':
+            case 'weightedsearch':
                 if ($adding) {
                     throw new InvalidArgumentException('invalid parameter access on ' . $name);
                 }
@@ -300,6 +307,18 @@ public function set($name, $value, $adding = false)
 
             case 'subfilters':
                 throw new RuntimeException('invalid access on sub filters');
+
+            case 'weightedfields':
+                if ($adding) {
+                    throw new InvalidArgumentException('invalid parameter access on ' . $name);
+                }
+
+                if (! is_array($value)) {
+                    throw new InvalidArgumentException('invalid query fields option');
+                }
+
+                $this->data[$name] = $value;
+                break;
         }
 
         return $this;

src/Solr/Solarium/Adapter.php

@@ -77,6 +77,7 @@
 use function file_exists;
 use function filesize;
 use function filter_var;
+use function implode;
 use function in_array;
 use function intval;
 use function is_array;
@@ -615,6 +616,19 @@ protected function applyParametersOnQuery(
                 $query->setSorts($sortings);
             }
 
+            $isWeightedSearch = $parameters->getWeightedSearch();
+            if ($isWeightedSearch === true) {
+                // get the edismax component
+                $edismax = $query->getEDisMax();
+
+                // NOTE: query is now an edismax query
+                $weightedFields = $parameters->getWeightedFields();
+                if (! empty($weightedFields)) {
+                    $queryFields = $this->getQueryFieldsString($weightedFields);
+                    $edismax->setQueryFields($queryFields);
+                }
+            }
+
             $facet = $parameters->getFacet();
             if ($facet !== null) {
                 $facetSet = $query->getFacetSet();
@@ -880,4 +894,21 @@ public function setTimeout($timeout)
             $this->client->setOptions($options, true);
         }
     }
+
+    /**
+     * Converts an array containing boost factors keyed by field into a query fields string that can be used
+     * as input for the Solr `qf` request parameter.
+     *
+     * @param int[] $weightedFields assigns boost factors to fields, e.g.: [ 'title' => 10, 'abstract' => 0.5 ]
+     * @return string query fields string, e.g.: "title^10 abstract^0.5"
+     */
+    protected function getQueryFieldsString($weightedFields)
+    {
+        $queryFields = [];
+        foreach ($weightedFields as $field => $boostFactor) {
+            $queryFields[] = "$field^$boostFactor";
+        }
+
+        return implode(' ', $queryFields);
+    }
 }

test/Solr/Solarium/AdapterSearchingTest.php

@@ -33,6 +33,7 @@
 namespace OpusTest\Search\Solr\Solarium;
 
 use Exception;
+use Opus\Common\Config;
 use Opus\Common\Person;
 use Opus\Search\Query;
 use Opus\Search\QueryFactory;
@@ -43,6 +44,7 @@
 use OpusTest\Search\TestAsset\DocumentBasedTestCase;
 
 use function count;
+use function round;
 
 class AdapterSearchingTest extends DocumentBasedTestCase
 {
@@ -248,4 +250,50 @@ public function testMapYearFacetIndexFieldsToYearAsset()
 
         $this->assertEquals(1, $result->getAllMatchesCount());
     }
+
+    public function testSearchWithQueryParserEDisMax()
+    {
+        // assign boost factors to fields
+        $this->adjustConfiguration([
+            'search' => [
+                'simple' => [
+                    'title'    => 10,
+                    'abstract' => 0.5,
+                ],
+            ],
+        ]);
+
+        $config         = Config::get();
+        $weightedFields = $config->search->simple->toArray();
+
+        $docA = $this->createDocument('testdocA'); // phrase 'test document' only occurs in abstract
+        $docB = $this->createDocument('testdocB'); // phrase 'test document' occurs in title & abstract
+
+        $index = Service::selectIndexingService(null, 'solr');
+        $index->addDocumentsToIndex([$docA, $docB]);
+
+        $search = Service::selectSearchingService(null, 'solr');
+
+        $query = new Query();
+
+        // use the Solr eDisMax query parser (i.e., add Solr request param `defType=edismax`)
+        $query->setWeightedSearch(true);
+
+        // add Solr request param `qf=...` which assigns boost factors to fields
+        $query->setWeightedFields($weightedFields);
+
+        $filter = $search->createFilter();
+        $filter->createSimpleEqualityFilter('*')->addValue('test document');
+        $query->setFilter($filter);
+
+        $result  = $search->customSearch($query);
+        $matches = $result->getReturnedMatches();
+
+        $this->assertEquals(2, count($matches));
+
+        $firstResultScore  = $matches[0]->getScore();
+        $secondResultScore = $matches[1]->getScore();
+
+        $this->assertTrue(round($firstResultScore, 1) > round($secondResultScore, 1));
+    }
 }

test/TestAsset/DocumentBasedTestCase.php

@@ -153,6 +153,26 @@ class DocumentBasedTestCase extends TestCase
             'BelongsToBibliography'   => 1,
             'EmbargoDate'             => '2010-01-04',
         ],
+        'testdocA'  => [
+            'TitleMain'     => [
+                'Value'    => 'Some Document',
+                'Language' => 'eng',
+            ],
+            'TitleAbstract' => [
+                'Value'    => 'Abstract of test document A.\nSome more text.',
+                'Language' => 'eng',
+            ],
+        ],
+        'testdocB'  => [
+            'TitleMain'     => [
+                'Value'    => 'Another Test Document',
+                'Language' => 'eng',
+            ],
+            'TitleAbstract' => [
+                'Value'    => 'Abstract of test document B.\nSome blah blah text.',
+                'Language' => 'eng',
+            ],
+        ],
     ];
 
     /**