Improve support for result grouping

src/HAB/Solr/Response/Json/Group.php

+<?php
+
+/**
+ * This file is part of HAB Solr.
+ *
+ * HAB Solr is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HAB Solr is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HAB Solr.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2017 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+
+namespace HAB\Solr\Response\Json;
+
+use Countable;
+
+/**
+ * Result group.
+ *
+ * @author    David Maus <maus@hab.de>
+ * @copyright (c) 2017 by Herzog August Bibliothek Wolfenbüttel
+ * @license   http://www.gnu.org/licenses/gpl.txt GNU General Public License v3 or higher
+ */
+class Group implements Countable
+{
+    private $groupValue;
+    private $records;
+
+    public function __construct (array $group)
+    {
+        $this->groupValue = $group['groupValue'];
+        $this->records = array();
+        foreach ($group['doclist']['docs'] as $record) {
+            $this->records []= new Record($record);
+        }
+    }
+
+    public function getGroupValue ()
+    {
+        return $this->groupValue;
+    }
+
+    public function count ()
+    {
+        return count($this->records);
+    }
+
+    public function getRecords ()
+    {
+        return $this->records;
+    }
+}
\ No newline at end of file

src/HAB/Solr/Response/Json/RecordCollection.php

@@ -51,7 +51,7 @@ class RecordCollection implements Iterator
      */
     protected static $template = array(
         'responseHeader' => array(),
-        'response'       => array('numFound' => 0, 'start' => 0),
+        'response'       => array('numFound' => 0, 'start' => 0, 'docs' => array()),
         'spellcheck'     => array('suggestions' => array()),
         'facet_counts'   => array(),
     );
@@ -275,8 +275,18 @@ class RecordCollection implements Iterator
      */
     public function getGroups()
     {
-        return isset($this->response['grouped'])
-            ? $this->response['grouped'] : array();
+        if (is_null($this->groups)) {
+            $this->groups = array();
+            if (isset($this->response['grouped'])) {
+                foreach ($this->response['grouped'] as $field => $group) {
+                    $this->groups[$field] = array();
+                    foreach ($group['groups'] as $data) {
+                        $this->groups[$field] []= new Group($data);
+                    }
+                }
+            }
+        }
+        return $this->groups;
     }
 
     /**