MARS Trading System

From Multiverse

MARS

Building MARS With Ant

Mob Server

Quests  •  Adding Mobs

Object Manager

Objects  •  Trading System  •  Adding Consumable Items

Combat Server

Abilities and Combat Plugin  •  Combat Statistics  •  Extending the MARS Combat System  •  Group System  •  Trainer Plug-in  •  Professions  •  Experience System

Tutorials

Defining Quests  •  Scripting Mobs  •  Defining Items

Other Examples

Triggering an Action with a Mouseclick  •  Scheduled Execution  •  Working with Sound  •  Creating a Teleporter

Contents 1 Overview 2 Files 2.1 Client 2.2 Server 3 Messaging 4 API 4.1 Events

Overview

The MARS trading system allows two players or mobs to trade items with each other. Both parties update their offers and after both have accepted the trade, the inventory plugin transfers the items. When either offer changes, the accepted flags are cleared so both traders must accept the final transaction.

To begin a trade, target the player or NPC you want to trade with and use the "/trade" command. The trade window will open and you will be able to drag and drop items from your inventory into the right pane of the trade window. Items offered by the other player will appear in the left pane. When you are satisfied with the two offers, click the "Accept" button and once both players have accepted the trade, it will be completed.

NOTE: to drag items, click on them, but do not hold the mouse button down; then you'll be able to drag them to the trade window.

See also MarsTrade, the client-side example implementation of the trading system in Sampleworld.

Files

The MARS secure trading system requires both client and server code and some UI files. All these files are included in the Sampleworld asset repository.

Client

The Client requires some UI files and script files. Add the following files from the Sampleworld asset repository to your asset repository:

• FrameXML file MvSecureTrade.xml
• UI script fle MvSecureTrade.py
• Imageset MvButtons, and the corresponding imagefile MvButtons.tga.
• The MarsTrade scripting class in the MARS Client Scripting Library.

You must add MvSecureTrade.xml to the theme (.toc) file that defines your UI.

Server

By default, the MARS trading system runs in the object manager plug-in process, which loads multiverse.mars.plugins.MarsInventoryPlugin. This is the default behavior using the standard server start script (multiverse.sh or start-multiverse.bat).

Make sure your config/common/proxy.py has the the TradeStartCommand command handler.

Messaging

The trading system uses five messages defined in multiverse.mars.plugins.MarsInventoryClient, described in the following table.

Message	Sent by	Description
TradeStartReqMessage	Trader	Request to start a new trading session
TradeOfferReqMessage	Trader	Request to update or cancel a trade offer
TradeStartMessage	Inventory plugin	Notification that a new trading session has started
TradeCompleteMessage	Inventory plugin	Notification that a trading session has finished
TradeOfferUpdateMessage	Inventory plugin	Notification that a trading session has changed

API

Two methods in multiverse.mars.plugins.MarsInventoryClient help conduct trades. The tradeStart() method starts a trade between requesterOid and partnerOid:

public static void tradeStart(Long requesterOid,
                              Long partnerOid);

The tradeUpdate() method updates a trade session with a new offer and accepted flag. If cancelled is true, the trade session is cancelled.

public static void tradeUpdate(Long requesterOid,
                               Long partnerOid,
                               LinkedList<Long> offerItems,
                               boolean accepted,
                               boolean cancelled);

The TradeStartCommand method in multiverse/config/common/proxy.py calls the tradeStart() method>

class TradeStartCommand (ProxyPlugin.CommandParser):
   def parse(self, cmdEvent):
       playerOid = cmdEvent.getObjectOid()
       targetOid = cmdEvent.getTarget()
       MarsInventoryClient.tradeStart(playerOid, targetOid)

Events

When the TradeStartCommand method is called, it triggers the event multiverse.mars.events.TradeStartReqEvent.

evtSvr.registerEventId(33, "multiverse.mars.events.TradeStartReqEvent")