new JSON response method "message" to call egw.message eg. in a popup, by using the context from the egw.json call

api/js/jsapi/egw_json.js

@@ -368,6 +368,17 @@ egw.extend('json', egw.MODULE_WND_LOCAL, function(_app, _wnd)
 		throw 'Invalid parameters';
 	}, null, 'alert');
 
+	// Regisert the "message" plugin
+	json.registerJSONPlugin(function(type, res, req) {
+		//Check whether all needed parameters have been passed and call the alertHandler function
+		if ((typeof res.data.message != 'undefined'))
+		{
+			req.egw.message(res.data.message, res.data.type);
+			return true;
+		}
+		throw 'Invalid parameters';
+	}, null, 'message');
+
 	// Register the "assign" plugin
 	json.registerJSONPlugin(function(type, res, req) {
 		//Check whether all needed parameters have been passed and call the alertHandler function

api/src/Json/Msg.php

@@ -40,6 +40,29 @@ abstract class Msg
 		}
 	}
 
+	/**
+	 * Adds an "alert" to the response which can be handeled on the client side.
+	 *
+	 * The default implementation simply displays the text supplied here with the JavaScript function "alert".
+	 *
+	 * @param string $message contains the actual message being sent to the client.
+	 * @param string $type =null (optional) "success", "error" or "info",
+	 * null: check for "error" in message and use "error" in that case, otherwise "success"
+	 */
+	public function message($message, $type = null)
+	{
+		if (is_string($message) && (is_string($type) || is_null($type)))
+		{
+			$this->addGeneric('message', array(
+				"message" => $message,
+				"type" => $type));
+		}
+		else
+		{
+			throw new Exception("Invalid parameters supplied.");
+		}
+	}
+
 	/**
 	 * Allows to add a generic java script to the response which will be executed upon the request gets received.
 	 *