Cloud Gem Message of the Day Implementation Details - Lumberyard User Guide

Cloud Gem Message of the Day Implementation Details

This section describes the entity, component, Lua script, and resources used by the Message of the Day Cloud Gem.

Entity and Component

The Message of the Day sample uses an entity called MOTDMenu that contains the CloudGemMessageOfTheDayClientComponent.

        Message of the day entity and client component

The CloudGemMessageOfTheDayClientComponent component gives the entity access to the game client API operations so that it can receive callback results.

The motdmainmenu.lua Script

The MOTDmenu entity also contains a Lua script component that executes the dev\CloudGemSamples\Scripts\motdmainmenu.lua script.

The following code from the script shows how CloudGemMessageOfTheDayRequestBus is used to call GetPlayerMessages.

function motdmainmenu:OnAction(entityId, actionName) Debug.Log(tostring(entityId) .. ": " .. actionName) if actionName == "GetMessages" then if CloudGemMessageOfTheDayRequestBus.Event == nil then Debug.Log("No Message Request Event found") return end local timeVal ="%b %d %Y %H:%M") local lang = "Eng" Debug.Log(timeVal); CloudGemMessageOfTheDayRequestBus.Event.GetPlayerMessages(self.entityId, timeVal, lang, nil) end end

The following code from the script shows the CloudGemMessageOfTheDayNotificationBus and the result callback functions OnGetPlayerMessagesRequestSuccess(response) and OnGetPlayerMessagesRequestError(errorMsg) that it connects to.

function motdmainmenu:OnActivate() ... self.notificationHandler = CloudGemMessageOfTheDayNotificationBus.Connect(self, self.entityId) end ... function motdmainmenu:OnGetPlayerMessagesRequestSuccess(response) Debug.Log("GetPlayerMessages succeeded") self.messageQueue = {} self.displayTimer = 0.0 Debug.Log("Response messages: "..tostring(#response.list)); --This is a callback from C++ with an object containing a vector called list. --Therefore we cannot treat it as a regular Lua table and must rely on the reflected methods and operators of the reflected vector class --for msgCount = 1, table.getn(response) do -- Debug.Log(response[msgCount]) -- table.insert(self.messageQueue, response[msgCount]) for msgCount = 1, #response.list do Debug.Log(tostring(response.list[msgCount].message)) table.insert(self.messageQueue, response.list[msgCount]) end end function motdmainmenu:OnGetPlayerMessagesRequestError(errorMsg) Debug.Log("GetPlayerMessages Error") end

Cloud Gem Message of the Day Resources

The Cloud Canvas Message of the Day sample has a resource group that contains an Amazon DynamoDB table called Main Table, which is the database for the messages. Table entries are keyed on a server-generated unique message ID. Each entry has the following attributes.

Main Table Attributes
Attribute Type Description
UniqueMsgID string The server-generated unique message ID.
startTime datetime Time when the message should start appearing.
endTime datetime Time when the message expires.
priority integer Relative priority of the message. 0 is the highest priority.
message string The message body. The string size is limited to 768 characters.