Implement last message cache from chats

retroshare-qml-app/src/ChatCache.qml

@@ -0,0 +1,40 @@
+pragma Singleton
+
+import QtQml 2.7
+import QtQuick.Controls 2.0
+import org.retroshare.qml_components.LibresapiLocalClient 1.0
+import Qt.labs.settings 1.0
+
+QtObject {
+
+	id: chatCache
+
+	property QtObject lastMessageCache: QtObject
+	{
+		property var lastMessageList: ({})
+
+		function updateLastMessageCache (chatId, chatModel){
+			console.log("updateLastMessageCache (chatId, chatModel)", chatId)
+
+			if (!chatModel) {
+				rsApi.request( "/chat/messages/"+chatId, "", function (par){
+					updateLastMessage(chatId, par.response)
+				})
+			} else {
+				updateLastMessage (chatId, chatModel)
+			}
+		}
+
+		function updateLastMessage (chatId, chatModel){
+			var lastMessage = getLastMessage (chatModel)
+			lastMessageList[chatId] = lastMessage
+		}
+
+		function getLastMessageFromChat (chatModel){
+			console.log("getLastMessage (chatMessages)")
+			var messagesData = JSON.parse(chatMessages).data
+			return messagesData.slice(-1)[0]
+		}
+	}
+
+}