商業(yè)化IM 客戶端接口設(shè)計(jì)分析

　　對(duì)于剛接觸IM（即時(shí)通訊）開發(fā)，通過閱讀成熟的商業(yè)代碼能夠?qū)磿r(shí)通訊軟件大體上有個(gè)認(rèn)識(shí)，比如消息發(fā)送，消息接受，消息監(jiān)聽，群聊，單聊，聊天室。我這邊直接拿[Gobelieve IM] 源碼來做剖析。IMService在代碼層級(jí)里起著承上啟下的作用，負(fù)責(zé)發(fā)送消息，接受消息（聊天消息，系統(tǒng)消息，控制命令消息（比如邀請(qǐng)VOIP，退群，加群）），消息在客戶端轉(zhuǎn)發(fā)，消息類型判斷和分發(fā)，消息observer的增加和刪除，IMService本身會(huì)根據(jù)業(yè)務(wù)需求實(shí)現(xiàn)handlers對(duì)接到數(shù)據(jù)傳輸層（socket）。Observers是銜接IMService和UI層。如果只側(cè)重于UI層開發(fā)，重點(diǎn)是Observers，比如PeerMessageObserver是一對(duì)一聊天監(jiān)聽，GroupMessageObserver:群聊天監(jiān)聽，RoomMessageObserver:聊天室監(jiān)聽。

@class IMessage;

　　IMessage 模型類的前置聲明

@protocol IMPeerMessageHandler <NSObject>
-(BOOL)handleMessage:(IMMessage*)msg uid:(int64_t)uid;
-(BOOL)handleMessageACK:(int)msgLocalID uid:(int64_t)uid;
-(BOOL)handleMessageFailure:(int)msgLocalID uid:(int64_t)uid;
@end

    一對(duì)一聊天的hanlder定義，IM有一個(gè)ACK的設(shè)計(jì)，用來顯示消息是否已經(jīng)通過服務(wù)器下發(fā)到對(duì)方客戶端。具體的函數(shù)，handleMessage()接收到消息的處理函數(shù)。handleMessageACK()接收到消息已讀的處理函數(shù)。 handleMessageFailure()接收到消息發(fā)送失敗的處理函數(shù)。 

@protocol IMGroupMessageHandler <NSObject>

-(BOOL)handleMessage:(IMMessage*)msg;
-(BOOL)handleMessageACK:(int)msgLocalID gid:(int64_t)gid;
-(BOOL)handleMessageFailure:(int)msgLocalID gid:(int64_t)gid;

-(BOOL)handleGroupNotification:(NSString*)notification;
@end

     群聊天的hanlder定義，接口上比單聊多一個(gè)群狀態(tài)改變的處理，還有就是單聊下發(fā)的是個(gè)人ID，群聊下發(fā)的是群聊ID，同樣的函數(shù)，handleMessage()接收到消息的處理函數(shù)。handleMessageACK()接收到消息已讀的處理函數(shù)。 handleMessageFailure()接收到消息發(fā)送失敗的處理函數(shù)。handleGroupNotification(),處理群狀態(tài)改變的函數(shù)，比如群名稱改變，群成員改變，群解散等等事件。 

@protocol IMCustomerMessageHandler <NSObject>
-(BOOL)handleCustomerSupportMessage:(CustomerMessage*)msg;
-(BOOL)handleMessage:(CustomerMessage*)msg;
-(BOOL)handleMessageACK:(CustomerMessage*)msg;
-(BOOL)handleMessageFailure:(CustomerMessage*)msg;
@end

　　客服聊天的handler定義。 

@protocol LoginPointObserver <NSObject>
//用戶在其他地方登陸
-(void)onLoginPoint:(LoginPoint*)lp;
@end

　　多端登錄事件監(jiān)聽。 

@protocol PeerMessageObserver <NSObject>
@optional
-(void)onPeerMessage:(IMMessage*)msg;

//服務(wù)器ack
-(void)onPeerMessageACK:(int)msgLocalID uid:(int64_t)uid;

//消息發(fā)送失敗
-(void)onPeerMessageFailure:(int)msgLocalID uid:(int64_t)uid;

//對(duì)方正在輸入
-(void)onPeerInputing:(int64_t)uid;

@end

　　一對(duì)一聊天的Observer的定義，提供了對(duì)輸入狀態(tài)監(jiān)聽的接口，用來實(shí)現(xiàn)，實(shí)時(shí)獲取對(duì)方是否在編輯消息。 

@protocol GroupMessageObserver <NSObject>
@optional
-(void)onGroupMessage:(IMMessage*)msg;
-(void)onGroupMessageACK:(int)msgLocalID gid:(int64_t)gid;
-(void)onGroupMessageFailure:(int)msgLocalID gid:(int64_t)gid;

-(void)onGroupNotification:(NSString*)notification;
@end

　　群聊天的Observer的定義。 

@protocol RoomMessageObserver <NSObject>
@optional
-(void)onRoomMessage:(RoomMessage*)rm;
-(void)onRoomMessageACK:(RoomMessage*)rm;
-(void)onRoomMessageFailure:(RoomMessage*)rm;

@end

　　聊天室消息Observer的定義。 

@protocol RTMessageObserver <NSObject>

@optional
-(void)onRTMessage:(RTMessage*)rt;

@end

@protocol SystemMessageObserver <NSObject>
@optional
-(void)onSystemMessage:(NSString*)sm;

@end

　　系統(tǒng)消息的Observer的定義。 

@protocol CustomerMessageObserver <NSObject>
@optional
-(void)onCustomerMessage:(CustomerMessage*)msg;
-(void)onCustomerSupportMessage:(CustomerMessage*)msg;

//服務(wù)器ack
-(void)onCustomerMessageACK:(CustomerMessage*)msg;
//消息發(fā)送失敗
-(void)onCustomerMessageFailure:(CustomerMessage*)msg;
@end

　　客服消息的Observer的定義。 

@protocol VOIPObserver <NSObject>

-(void)onVOIPControl:(VOIPControl*)ctl;

@end

　　支持整合VOIP功能的Observer的定義。 

@interface IMService : TCPConnection
@property(nonatomic, copy) NSString *deviceID;
@property(nonatomic, copy) NSString *token;
@property(nonatomic) int64_t uid;
//客服app需要設(shè)置，普通app不需要設(shè)置
@property(nonatomic) int64_t appID;

@property(nonatomic, weak)id<IMPeerMessageHandler> peerMessageHandler;//一對(duì)一聊天Handler
@property(nonatomic, weak)id<IMGroupMessageHandler> groupMessageHandler;//群聊handler
@property(nonatomic, weak)id<IMCustomerMessageHandler> customerMessageHandler;//客服handler

當(dāng)前的IMService實(shí)現(xiàn)了三個(gè)（一對(duì)一聊天，群聊，客服）handler，可以按自己需要增加新的handler類型。消息統(tǒng)一在IMService做轉(zhuǎn)發(fā)。
根據(jù)注冊(cè)的Observer，傳遞到對(duì)該消息類型感興趣的界面。

+(IMService*)instance;//IMService是單例的形式使用

-(BOOL)isPeerMessageSending:(int64_t)peer id:(int)msgLocalID;
-(BOOL)isGroupMessageSending:(int64_t)groupID id:(int)msgLocalID;
-(BOOL)isCustomerSupportMessageSending:(int)msgLocalID
                            customerID:(int64_t)customerID
                         customerAppID:(int64_t)customerAppID;
-(BOOL)isCustomerMessageSending:(int)msgLocalID storeID:(int64_t)storeID;

-(BOOL)sendPeerMessage:(IMMessage*)msg;
-(BOOL)sendGroupMessage:(IMMessage*)msg;
-(BOOL)sendRoomMessage:(RoomMessage*)msg;
//顧客->客服
-(BOOL)sendCustomerMessage:(CustomerMessage*)im;
//客服->顧客
-(BOOL)sendCustomerSupportMessage:(CustomerMessage*)im;
-(BOOL)sendRTMessage:(RTMessage*)msg;

-(void)enterRoom:(int64_t)roomID;
-(void)leaveRoom:(int64_t)roomID;

//正在輸入
-(void)sendInputing:(MessageInputing*)inputing;
//更新未讀的消息數(shù)目
-(void)sendUnreadCount:(int)unread;

-(void)addPeerMessageObserver:(id<PeerMessageObserver>)ob;
-(void)removePeerMessageObserver:(id<PeerMessageObserver>)ob;

-(void)addGroupMessageObserver:(id<GroupMessageObserver>)ob;
-(void)removeGroupMessageObserver:(id<GroupMessageObserver>)ob;

-(void)addLoginPointObserver:(id<LoginPointObserver>)ob;
-(void)removeLoginPointObserver:(id<LoginPointObserver>)ob;

-(void)addRoomMessageObserver:(id<RoomMessageObserver>)ob;
-(void)removeRoomMessageObserver:(id<RoomMessageObserver>)ob;

-(void)addSystemMessageObserver:(id<SystemMessageObserver>)ob;
-(void)removeSystemMessageObserver:(id<SystemMessageObserver>)ob;

-(void)addCustomerMessageObserver:(id<CustomerMessageObserver>)ob;
-(void)removeCustomerMessageObserver:(id<CustomerMessageObserver>)ob;

-(void)addRTMessageObserver:(id<RTMessageObserver>)ob;
-(void)removeRTMessageObserver:(id<RTMessageObserver>)ob;
    
-(void)pushVOIPObserver:(id<VOIPObserver>)ob;
-(void)popVOIPObserver:(id<VOIPObserver>)ob;

-(BOOL)sendVOIPControl:(VOIPControl*)ctl;

@end

　　坑下挖好，慢慢補(bǔ)充，完整的代碼和DEMO可以到[Gobelieve IM]查看。

[1]: http://developer.gobelieve.io/