Can not read data from server using GCDAsyncSocket - ios

Question

I tried to connect to the server and send some information to the server(like username, password..), and the server send me back the ID (string type). The problem is I can not get the ID. Could anyone help me? I am beginner in IOS coding. Thanks.
Here is the codes:
After I click the button, it will call my own function to get serverIP which is a string and Port which is a int.
Then that function will call this function to connect the server:
(void)logInCheck {
asyncSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];
NSError *error = nil;
uint16_t port = serverPort;
if (![asyncSocket connectToHost:serverIP onPort:port error:&error])
{
DDLogError(#"Unable to connect to due to invalid configuration: %#", error);
}
else
{
DDLogVerbose(#"Connecting...");
[self passDataToServer];
}
}
//DataPassToServer is a NSString that hold my data
(void)passDataToServer
{
NSData *requestData = [DataPassToServer dataUsingEncoding:NSUTF8StringEncoding];
[asyncSocket writeData:requestData withTimeout:-1.0 tag:0];
[asyncSocket readDataWithTimeout:-1 tag:0];
}
//this function call successfully
-(void)socket:(GCDAsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port
{
DDLogVerbose(#"socket:didConnectToHost:%# port:%hu", host, port);
}
//this function call successfully
(void)socket:(GCDAsyncSocket *)sock didWriteDataWithTag:(long)tag
{
DDLogVerbose(#"socket:didWriteDataWithTag:");
}
//This function does not run !!! Nothing print out.
(void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
DDLogVerbose(#"socket:didReadData:withTag:");
NSString *response = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"ID = %#",response);
[asyncSocket readDataWithTimeout:-1 tag:0];
}

Answer 1

I don't know about your server implementation but, most implementations would read up to the first newline character before processing the request.
So make sure that your [DataPassToServer dataUsingEncoding:NSUTF8StringEncoding] includes a newline character ("\n") at the end.
Your code looks fine and works for me.