passing query parameters to options to search interfaces

Controller/SearchController.php

@@ -92,7 +92,11 @@ class SearchController extends Controller
                             $name,
                             $paginatorFactory->getCurrentPageFirstItemNumber(),
                             $paginatorFactory->getCurrentItemsPerPage(),
-                            array(SearchInterface::SEARCH_PREVIEW_OPTION => false),
+                            array(
+                                SearchInterface::SEARCH_PREVIEW_OPTION => false,
+                                SearchInterface::REQUEST_QUERY_PARAMETERS => $request
+                                    ->get(SearchInterface::REQUEST_QUERY_KEY_ADD_PARAMETERS, [])
+                                ),
                             $_format
                             )];
                 

Search/SearchInterface.php

@@ -33,6 +33,16 @@ interface SearchInterface
 {
 
     const SEARCH_PREVIEW_OPTION = '_search_preview';
+    
+    /**
+     * Request parameters contained inside the `add_q` parameters
+     */
+    const REQUEST_QUERY_PARAMETERS = '_search_parameters';
+    
+    /**
+     * Supplementary parameters to the query string
+     */
+    const REQUEST_QUERY_KEY_ADD_PARAMETERS = 'add_q';
 
    /** 
     * return the result in a html string. The string will be inclued (as raw)