enh(charts): add new methods in graph backend

www/api/class/centreon_home_customview.class.php

@@ -321,6 +321,27 @@ public function getPreferences()
         return $tpl->fetch("widgetParam.html");
     }
 
+    /**
+     * Get preferences by widget id
+     *
+     * @return array The widget preferences
+     * @throws \Exception When missing argument
+     */
+    public function getPreferencesByWidgetId()
+    {
+        global $centreon;
+
+        if (!isset($this->arguments['widgetId'])) {
+            throw new \Exception('Missing argument : widgetId');
+        }
+        $widgetId = $this->arguments['widgetId'];
+        $widgetObj = new CentreonWidget($centreon, $this->pearDB);
+
+        $preferences = $widgetObj->getWidgetPreferences($widgetId);
+
+        return $preferences;
+    }
+
     /**
      * Authorize to access to the action
      *