Added support for a relevance sort override for empty Solr/Summon sea…

…rches.

config/vufind/Summon.ini

@@ -9,6 +9,11 @@
 ; option should be one of the options present in the [Sorting] section below.
 default_sort         = relevance
 
+; This setting controls the sort order to be used for empty search when relevance
+; sort is selected. Since relevance doesn't have a meaningful function with an empty
+; search, this can be set to e.g. "PublicationDate:desc".
+;empty_search_relevance_override = "PublicationDate:desc"
+
 ; This setting controls the default view for search results; the selected option
 ; should be one of the options present in the [Views] section below.
 default_view         = list

config/vufind/searches.ini

@@ -8,6 +8,11 @@ default_handler      = AllFields    ; Search handler to use if none is specified
 ; below.
 default_sort         = relevance
 
+; This setting controls the sort order to be used for empty search when relevance
+; sort is selected. Since relevance doesn't have a meaningful function with an empty
+; search, this can be set to e.g. "title".
+;empty_search_relevance_override = title
+
 ; This setting controls the default view for search results; the selected option
 ; should be one of the options present in the [Views] section below.
 default_view         = list

module/VuFind/src/VuFind/Search/Solr/Options.php

@@ -59,6 +59,13 @@ class Options extends \VuFind\Search\Base\Options
      */
     protected $hierarchicalFacetSeparators = [];
 
+    /**
+     * Relevance sort override for empty searches
+     *
+     * @var string
+     */
+    protected $emptySearchRelevanceOverride = null;
+
     /**
      * Constructor
      *
@@ -78,6 +85,10 @@ public function __construct(\VuFind\Config\PluginManager $configLoader)
         if (isset($searchSettings->General->default_sort)) {
             $this->defaultSort = $searchSettings->General->default_sort;
         }
+        if (isset($searchSettings->General->empty_search_relevance_override)) {
+            $this->emptySearchRelevanceOverride
+                = $searchSettings->General->empty_search_relevance_override;
+        }
         if (isset($searchSettings->DefaultSortingByType)
             && count($searchSettings->DefaultSortingByType) > 0
         ) {
@@ -252,6 +263,16 @@ public function getAdvancedSearchAction()
         return 'search-advanced';
     }
 
+    /**
+     * Get the relevance sort override for empty searches.
+     *
+     * @return string Sort field or null if not set
+     */
+    public function getEmptySearchRelevanceOverride()
+    {
+        return $this->emptySearchRelevanceOverride;
+    }
+
     /**
      * Get an array of hierarchical facets.
      *

module/VuFind/src/VuFind/Search/Solr/Params.php

@@ -475,6 +475,13 @@ public function getBackendParameters()
         // Sort
         $sort = $this->getSort();
         if ($sort) {
+            // If we have an empty search with relevance sort, see if there is
+            // an override configured:
+            if ($sort == 'relevance' && $this->getQuery()->getAllTerms() == ''
+                && ($relOv = $this->getOptions()->getEmptySearchRelevanceOverride())
+            ) {
+                $sort = $relOv;
+            }
             $backendParams->add('sort', $this->normalizeSort($sort));
         }
 

module/VuFind/src/VuFind/Search/Summon/Options.php

@@ -52,6 +52,13 @@ class Options extends \VuFind\Search\Base\Options
      */
     protected $maxTopicRecommendations = false;
 
+    /**
+     * Relevance sort override for empty searches
+     *
+     * @var string
+     */
+    protected $emptySearchRelevanceOverride = null;
+
     /**
      * Constructor
      *
@@ -142,6 +149,10 @@ public function __construct(\VuFind\Config\PluginManager $configLoader)
                 $this->defaultSortByHandler[$key] = $val;
             }
         }
+        if (isset($searchSettings->General->empty_search_relevance_override)) {
+            $this->emptySearchRelevanceOverride
+                = $searchSettings->General->empty_search_relevance_override;
+        }
 
         // Load view preferences (or defaults if none in .ini file):
         if (isset($searchSettings->Views)) {
@@ -176,6 +187,16 @@ public function getAdvancedSearchAction()
         return 'summon-advanced';
     }
 
+    /**
+     * Get the relevance sort override for empty searches.
+     *
+     * @return string Sort field or null if not set
+     */
+    public function getEmptySearchRelevanceOverride()
+    {
+        return $this->emptySearchRelevanceOverride;
+    }
+
     /**
      * If there is a limit to how many search results a user can access, this
      * method will return that limit.  If there is no limit, this will return

module/VuFind/src/VuFind/Search/Summon/Params.php

@@ -154,9 +154,19 @@ public function getBackendParameters()
 
         $options = $this->getOptions();
 
+        $sort = $this->getSort();
+        if ($sort) {
+            // If we have an empty search with relevance sort, see if there is
+            // an override configured:
+            if ($sort == 'relevance' && $this->getQuery()->getAllTerms() == ''
+                && ($relOv = $this->getOptions()->getEmptySearchRelevanceOverride())
+            ) {
+                $sort = $relOv;
+            }
+        }
+
         // The "relevance" sort option is a VuFind reserved word; we need to make
         // this null in order to achieve the desired effect with Summon:
-        $sort = $this->getSort();
         $finalSort = ($sort == 'relevance') ? null : $sort;
         $backendParams->set('sort', $finalSort);