JavaScriptCore + Socket.IO

Question

I'm trying to connect to a Node.JS server with an iOS App, but instead of using a 3rd party native library, I'm trying to connect it with the JavaScript Socket.IO client & to pass the data that I'm receiving to my native code. I'm loading the Socket.IO module into the JSContext & it loads well, I can see all the available objects/functions inside the io object.

But when it reaches the line for connecting to my Node.JS server the execution of my JavaScript code stopes & I cannot find out why.

If I pause the app I don't see any additional threads for opening connections. Is it possible that JavaScriptCore doesn't have support for web sockets?

My Objective-C code:

JSContext *context = [JSContext new];

NSString *filePath = [[NSBundle mainBundle] pathForResource:@"socket.io" ofType:@"js"];
NSString *socketIO = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:&error];;


filePath = [[NSBundle mainBundle] pathForResource:@"client" ofType:@"js"];
NSString *client = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:&error];
context[@"socket_url"] = @"http://192.168.1.128:8080";
context[@"log"] = ^(NSString *string){

    NSLog(@"JavaScript:\n\t%@", string);
};
context[@"iOSBlock"] = ^(id deviceState) {

    id JSON = [NSJSONSerialization JSONObjectWithData:deviceState options:NSJSONReadingMutableLeaves error:nil];
    // I'll do something here if I get reach this part :)
};

[context evaluateScript:socketIO];
[context evaluateScript:client];

My JavaScript code:

var socket = io.connect(socket_url);

socket.on('connect', function(){
      log("Connected!");
});

socket.on('device-change', iOSBlock(deviceState)); 

Answer 1

JavaScriptCore itself only implements the ECMAScript spec . Stuff like XMLHTTPRequest, web sockets, DOM, etc. comes from WebKit. If you absolutely want to run the Socket.IO JavaScript client, you can perhaps use a hidden UIWebView, although I'd recommend using Socket.IO-objc .

On an unrelated note, you can see what errors JSContext generates by either inspecting its exception property, or by setting a block that prints the error to the exceptionHandler property:

context.exceptionHandler = ^(JSContext *context, JSValue *exception) {
    NSLog(@"[%@:%@:%@] %@\n%@", exception[@"sourceURL"], exception[@"line"], exception[@"column"], exception, [exception[@"stack"] toObject]);
};