Objective-C

WebSocket Connect through HTTP Proxy

See more WebSocket Examples

This example shows how to establish a WebSocket connection through an HTTP proxy server. Objective-C

#import <CkoRest.h>
#import <CkoSocket.h>
#import <CkoWebSocket.h>
#import <NSString.h>

BOOL success = NO;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// --------------------------------------------------
// This example borrows the code from the REST using HTTP Proxy example.
// We first use the Chilkat Socket object to establish a connection to the WebSocket server through an HTTP proxy.
// Next, the Rest object uses the Socket object for its connection.
// Finally, the WebSocket object uses the Rest object for its connection.  
// 

CkoRest *rest = [[CkoRest alloc] init];
CkoSocket *socket = [[CkoSocket alloc] init];

// Set the HTTP proxy domain or IP address, and port.
socket.HttpProxyHostname = @"192.168.1.79";
socket.HttpProxyPort = [NSNumber numberWithInt:808];

// Provide authentication to the HTTP proxy, if needed.
socket.HttpProxyUsername = @"HTTP_PROXY_LOGIN";
socket.HttpProxyPassword = @"HTTP_PROXY_PASSWORD";
socket.HttpProxyAuthMethod = @"Basic";

// Indicate that HTTP requests (i.e. the WebSocket opening handshake) will be sent over the socket.
// This is important for how the HTTP proxy connection is established.
socket.HttpProxyForHttp = YES;

// Connect to the websocket server through the HTTP proxy.
BOOL bTls = NO;
int port = 80;
int maxWaitMs = 5000;
success = [socket Connect: @"some-websocket-server.com" port: [NSNumber numberWithInt: port] ssl: bTls maxWaitMs: [NSNumber numberWithInt: maxWaitMs]];
if (success != YES) {
    NSLog(@"%@%d",@"Connect Failure Error Code: ",[socket.ConnectFailReason intValue]);
    NSLog(@"%@",socket.LastErrorText);
    return;
}

// Tell the Rest object to use the connected socket.
success = [rest UseConnection: socket autoReconnect: YES];
if (success != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

CkoWebSocket *ws = [[CkoWebSocket alloc] init];

// Tell the WebSocket to use this connection.
success = [ws UseConnection: rest];
if (success != YES) {
    NSLog(@"%@",ws.LastErrorText);
    return;
}

// Add the standard WebSocket open handshake headers that will be needed.
// (This adds the required HTTP request headers to the rest object.)
[ws AddClientHeaders];

// Add any additional headers that might be desired.
// Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
[rest AddHeader: @"Sec-WebSocket-Protocol" value: @"x-some-websocket-subprotocol"];
[rest AddHeader: @"Origin" value: @"http://some-websocket-server.com"];

// Do the open handshake.
NSString *responseBody = [rest FullRequestNoBody: @"GET" uriPath: @"/something"];
if (rest.LastMethodSuccess != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

// If successful, the HTTP response status code should be 101,
// and the response body will be empty. (If it failed, we'll have a look
// at the response body..)
int statusCode = [rest.ResponseStatusCode intValue];
NSLog(@"%@%d",@"Response status code: ",statusCode);

if (statusCode != 101) {
    NSLog(@"%@",responseBody);
    NSLog(@"%@",@"-- Failed because of unexpected response status code.");
    return;
}

// We have the expected 101 response, so let's now validate the 
// contents of the response, such as the value sent by the server in the
// Sec-WebSocket-Accept header. 
success = [ws ValidateServerHandshake];
if (success != YES) {
    NSLog(@"%@",ws.LastErrorText);
    return;
}

NSLog(@"%@",@"WebSocket connection successful.");

// The application may now begin sending and receiving frames on the WebSocket connection.
// (At this point, we're done with the rest and socket objects...)

NSLog(@"%@",@"Success.");