XMPP協議實現即時通訊底層書寫 （二）-- IOS XMPPFramework Demo+分析，xmppxmppframework

XMPP協議實現即時通訊底層書寫 （二）-- IOS XMPPFramework Demo+分析，xmppxmppframework

我希望，This is a new day! 

在看代碼之前，我覺得你還是應該先整理一下心情，來聽我說幾句：

首先，我希望你是在早上邊看這篇blog，然後一邊開始動手操作，如果你只是看blog而不去自己對比項目，作用不是很大。一日之計在於晨，所以懷著一顆對技術渴望，激動的，亢奮的心情去學習，你才能有所得。嗯，就拿鄙人當時做項目來說，每天早上起來的第一件事情，就是研究XMPPFramework作者的代碼，按照模組來分析和模仿書寫，睡覺的時候還在思考，分析，總結...

當然我並不是說每個Dev 都要向我這樣，只是希望你能保持一顆積極向上的心態去對待技術，對待你的工作。

that's all。

ResourceURL：https://github.com/robbiehanson/XMPPFramework  （如果你還在維護你現有的基於XMPP的產品，那麼你需要sometimes 去查看，原作者是否fix 一些bug）

IphoneXMPP Demo

1.AppDelegate.m

a.大概看下標頭檔，ok，別跳轉深入看了，下面我會教快速的看。See this method

有幾個地方需要注意：

  1）DDLog 用於不用不強求，鄙人喜歡乾淨清爽的控制台，所以就沒用這玩意，因為我並不是很依賴全部打log，而是斷點控制台po XXX方法，即時性找出問題修複bug

  2）配置XML Stream 流 ，給你的長串連裡面增加各種 buff，各種裝備，各種屬性。ok，不開玩笑了：），這個配置很重要，它決定了你的app需要支援哪些xmpp服務，決定了原作者（羅賓遜）哪些代碼功能模組是不需要生效的

  3）啟動串連，當然對應的也有一個cancel connect

b 設定你的 XML Stream ，開啟哪些功能

- (void)setupStream{NSAssert(xmppStream == nil, @"Method setupStream invoked multiple times");// Setup xmpp stream// // The XMPPStream is the base class for all activity.// Everything else plugs into the xmppStream, such as modules/extensions and delegates.xmppStream = [[XMPPStream alloc] init];#if !TARGET_IPHONE_SIMULATOR{// Want xmpp to run in the background?// // P.S. - The simulator doesn't support backgrounding yet.//        When you try to set the associated property on the simulator, it simply fails.//        And when you background an app on the simulator,//        it just queues network traffic til the app is foregrounded again.//        We are patiently waiting for a fix from Apple.//        If you do enableBackgroundingOnSocket on the simulator,//        you will simply see an error message from the xmpp stack when it fails to set the property.<span style="color:#66ff99;">xmppStream.enableBackgroundingOnSocket = YES;</span>}#endif// Setup reconnect// // The XMPPReconnect module monitors for "accidental disconnections" and// automatically reconnects the stream for you.// There's a bunch more information in the XMPPReconnect header file.xmppReconnect = [[XMPPReconnect alloc] init];// Setup roster// // The XMPPRoster handles the xmpp protocol stuff related to the roster.// The storage for the roster is abstracted.// So you can use any storage mechanism you want.// You can store it all in memory, or use core data and store it on disk, or use core data with an in-memory store,// or setup your own using raw SQLite, or create your own storage mechanism.// You can do it however you like! It's your application.// But you do need to provide the roster with some storage facility.xmppRosterStorage = [[XMPPRosterCoreDataStorage alloc] init];//xmppRosterStorage = [[XMPPRosterCoreDataStorage alloc] initWithInMemoryStore];xmppRoster = [[XMPPRoster alloc] initWithRosterStorage:xmppRosterStorage];xmppRoster.autoFetchRoster = YES;xmppRoster.autoAcceptKnownPresenceSubscriptionRequests = YES;// Setup vCard support// // The vCard Avatar module works in conjuction with the standard vCard Temp module to download user avatars.// The XMPPRoster will automatically integrate with XMPPvCardAvatarModule to cache roster photos in the roster.xmppvCardStorage = [XMPPvCardCoreDataStorage sharedInstance];xmppvCardTempModule = [[XMPPvCardTempModule alloc] initWithvCardStorage:xmppvCardStorage];xmppvCardAvatarModule = [[XMPPvCardAvatarModule alloc] initWithvCardTempModule:xmppvCardTempModule];</span>// Setup capabilities// // The XMPPCapabilities module handles all the complex hashing of the caps protocol (XEP-0115).// Basically, when other clients broadcast their presence on the network// they include information about what capabilities their client supports (audio, video, file transfer, etc).// But as you can imagine, this list starts to get pretty big.// This is where the hashing stuff comes into play.// Most people running the same version of the same client are going to have the same list of capabilities.// So the protocol defines a standardized way to hash the list of capabilities.// Clients then broadcast the tiny hash instead of the big list.// The XMPPCapabilities protocol automatically handles figuring out what these hashes mean,// and also persistently storing the hashes so lookups aren't needed in the future.// // Similarly to the roster, the storage of the module is abstracted.// You are strongly encouraged to persist caps information across sessions.// // The XMPPCapabilitiesCoreDataStorage is an ideal solution.// It can also be shared amongst multiple streams to further reduce hash lookups.xmppCapabilitiesStorage = [XMPPCapabilitiesCoreDataStorage sharedInstance];    xmppCapabilities = [[XMPPCapabilities alloc] initWithCapabilitiesStorage:xmppCapabilitiesStorage];    xmppCapabilities.autoFetchHashedCapabilities = YES;    xmppCapabilities.autoFetchNonHashedCapabilities = NO;// Activate xmpp modules[xmppReconnect         activate:xmppStream];[xmppRoster            activate:xmppStream];[xmppvCardTempModule   activate:xmppStream];[xmppvCardAvatarModule activate:xmppStream];[xmppCapabilities      activate:xmppStream];// Add ourself as a delegate to anything we may be interested in[xmppStream addDelegate:self delegateQueue:dispatch_get_main_queue()];[xmppRoster addDelegate:self delegateQueue:dispatch_get_main_queue()];// Optional:// // Replace me with the proper domain and port.// The example below is setup for a typical google talk account.// // If you don't supply a hostName, then it will be automatically resolved using the JID (below).// For example, if you supply a JID like 'user@quack.com/rsrc'// then the xmpp framework will follow the xmpp specification, and do a SRV lookup for quack.com.// // If you don't specify a hostPort, then the default (5222) will be used.//[xmppStream setHostName:@"talk.google.com"];//[xmppStream setHostPort:5222];// You may need to alter these settings depending on the server you're connecting tocustomCertEvaluation = YES;}

ok,let's begin.

1)建立一個XML stream 對象，這貨是幹嘛的呢。打個比喻：貨物運輸帶，上貨和下貨 都要靠這條帶子。誰讓這條帶子動起來？

長串連

它就是個馬達。

那麼這裡面的貨是啥呢？3種貨：美版，港版，日版，偶爾帶點國行。(*^__^*) 嘻嘻……，哈哈不開玩笑了。有三種貨：<iq> <p><message>,偶爾帶點其他標籤<a><r>什麼的。

索達斯內！~斯ko一！~是的，好厲害好棒噠！~發現昨天看得RFC6121有點關係啦。~\(≧▽≦)/~啦啦啦

2）是否開啟後台模式---NO，除非你有VOIP需要支援，不然後患無窮，現在github 上後台issue還有一大堆沒解決的呢，反正呢很複雜噠，我這菜逼就沒支援這貨

<span style="color:#66ff99;">xmppStream.enableBackgroundingOnSocket</span>

3）開啟重連機制（長串連必備，心跳啥的）

開啟roster（兩種形式：coreData儲存 or 開闢記憶體--臨時Object Storage Service），自動擷取伺服器上的roster資料？是否自動應答 已經存在訂閱出席訊息的小夥伴的訂閱請求，也就是說是否自動過濾掉已經訂閱過的訂閱或者是已經形成訂閱關係的使用者請求啦（痛點，後面章節細講）。開啟roster CoreDataStorage，也就是資料庫存CoreData儲技術。

開啟vCard（個人資訊詳情） module，二次封裝vCard Module開啟，並且啟動 vcard對應的coreData 儲存技術

開啟capabilitie，和與之的儲存技術。這貨當初看了好久噠，但是現在真忘記了。。。sorry，這塊需要找對應的XEP來進行腦補，不過貌似暫時用不到，就讓它預設吧。

原文連結傳送門

下面是 XMPPFramework的一個核心：multi delegate （作者專屬，膜拜！~）

[xmppStream addDelegate:self delegateQueue:dispatch_get_main_queue()];[xmppRoster addDelegate:self delegateQueue:dispatch_get_main_queue()];

對XML stream 進行添加一個Sub Delegate回調，在當前Class，在mainThread Queue中，

對roster 進行一個sub delegate回調，在當前Class，主線程隊列。

關於multi delegate 技術，建議好好看看裡面的具體實現，不要求你會寫，大概的核心思想能看懂就成，會return BOOL YES or NO 即可。。。

btw1：鄙人對這個multi delegate再次膜拜，當然他寫的很多東西，都是讓我膜拜的。。比如socket連結。。。XML解析，DDLog。。。反正好多，好了不說了，說多了都是淚，菜狗只能仰望大神。。

btw2：刷刷刷兩個小時過去了，洗洗睡了，寫blog真心很累。

btw3：伺服器那個水？問你呢，你們環境配好了沒，我這邊要example測試連接了，快給個帳號和密碼。勞資效率就是這麼高，一天搞定基本的資料連線了。

btw4：經理，我這邊還算順利，約有小成，你看這串連介面，成了，雖然介面醜了點，但是能連上服務端了，真棒。

btw5：啪！你個傻蛋，別說這事demo，怎麼有你這種隊友。

btw6：下期預告<IOS XMPPFramework --IM底層架構設計+技術準備工作>