xmpp 带内注册

1 带内注册（In-band registration）的概念
带内注册指的是未在你的服务器上开通账号的用户可以通过xmpp协议注册新账号。相反的概念是带外注册（out-of-band registration），例如
你必须到某个指定的web页面进行注册。
如果服务器允许带内注册，那么我们就可以通过自己开发的客户端注册新账号。与带内注册相关的协议是XEP-0077。

2 使用XMPPFramework进行带内注册
XMPPStream.h中声明了进行简单带内注册(提供用户名和密码进行注册)的函数
- (BOOL)registerWithPassword:(NSString *)password error:(NSError **)errPtr;
注册前需要先建立stream连接, 因为没有账号,所以需要建立匿名连接

NSError *err; 
     NSString *tjid = [[NSString alloc] initWithFormat:@"anonymous@%@", server.text];
    [[delegate xmppStream] setMyJID:[XMPPJID jidWithString:tjid]];
    if ( ![[delegate xmppStream] connect:&err])
    {
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"连接服务器失败" 
                                                            message:[err localizedDescription]
                                                           delegate:nil 
                                                  cancelButtonTitle:@"Ok" 
                                                  otherButtonTitles:nil];
        [alertView show];

    }

建立连接之后, 不需要进行用户验证, 可以如下处理 -- 如果是在注册,则跳过验证这一步

- (void)xmppStreamDidConnect:(XMPPStream *)sender
{
    DDLogVerbose(@"%@: %@", THIS_FILE, THIS_METHOD);
    
    isXmppConnected = YES;
    
    NSError *error = nil;
    if (isRegister == YES)
        return;

    if (![[self xmppStream] authenticateWithPassword:password error:&error])
    {
        DDLogError(@"Error authenticating: %@", error);
    }
}

xmppStream connect 是立即返回的, 所以connect返回并不能说明连接已经建立好.
[delegate xmppStream] isConnected 为YES时才能确定连接已经建立好.

连接建立好之后,我们就可以发注册信息

    NSString *jid = [[NSString alloc] initWithFormat:@"%@@%@", user.text, server.text];
    [[delegate xmppStream] setMyJID:[XMPPJID jidWithString:jid]];
    NSError *error=nil;
    if (![[delegate xmppStream] registerWithPassword:password.text error:&error])
    {
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"创建账号失败" 
                                                            message:[error localizedDescription]
                                                           delegate:nil 
                                                  cancelButtonTitle:@"Ok" 
                                                  otherButtonTitles:nil];
        [alertView show];
    }

registerWithPassword:error 方法也是立即返回的
需要通过代理方法来判断注册是否成功
注册成功会调用:- (void)xmppStreamDidRegister:(XMPPStream *)sender
注册失败会调用:- (void)xmppStream:(XMPPStream *)sender didNotRegister:(NSXMLElement *)error

- (void)xmppStreamDidRegister:(XMPPStream *)sender
{
    DDLogVerbose(@"%@: %@", THIS_FILE, THIS_METHOD);
    registerSuccess = YES;
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"创建账号成功" 
                                                        message:@""
                                                       delegate:self 
                                              cancelButtonTitle:@"Ok" 
                                              otherButtonTitles:nil];
    [alertView show];
}

- (void)xmppStream:(XMPPStream *)sender didNotRegister:(NSXMLElement *)error
{
    DDLogVerbose(@"%@: %@", THIS_FILE, THIS_METHOD);
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"创建账号失败" 
                                                        message:@"用户名冲突"
                                                       delegate:nil 
                                              cancelButtonTitle:@"Ok" 
                                              otherButtonTitles:nil];
    [alertView show];
}