Socket.io-client-swift: Can't emit a dictionary

[vshahpledge]

Our socket.io api is expecting a dictionary as the top level object, but all of the emit calls in socket.io-swift only accept an array of items.

Server is expecting

    {
        token: abcdefg
        version: 1.1.0
    }

Server is getting

    [{
        token: abcdefg
        version: 1.1.0
    }]

Proposal: add another emit method that accepts non-array items.

[nuclearace]

How are you emitting?

[vshahpledge]

My emit call looked like this:

    let authDict = ["token": self.keychainManager.token,
                  "version": "1.1.0"]
    self.io.emit("authentication", authDict)

[vshahpledge]

I've submitted a PR: #572

[vshahpledge]

You can see the issue here:

public func emit(_ event: String, _ items: SocketData...) {...}
public func emitWithAck(_ event: String, _ items: SocketData...) -> OnAckCallback {...}

both emit methods only accept arrays of SocketData.

[nuclearace]

Right but that's because you can do

socket.emit("someEvent", 1, {"test": 1}, true)

And then do

socket.on("someEvent", (int, obj, bool) => { })

In JavaScript.

[nuclearace]

If you're getting something enclosed in an array that means something is broken with the encoder. Either they've changed the socket.io protocol on me or something else is going on.

[vshahpledge]

In Swift when you define a parameter in a method like items: SocketData... items automatically becomes an array.

from the docs:

The values passed to a variadic parameter are made available within the function’s body as an array of the appropriate type.

So even for a single item passed in to the method (in my case, a dictionary) it gets stored in an array.

[nuclearace]

Right, and in the socket.io protocol data is sent in the format 2["someEvent", arg1, arg2, arg3]. Which is why I do https://github.com/socketio/socket.io-client-swift/blob/master/Source/SocketIOClient.swift#L211.

So that when it gets to https://github.com/socketio/socket.io-client-swift/blob/master/Source/SocketPacket.swift#L89 it turns it into that proper format.

[nuclearace]

And there are tests for the parsing and encoding, so I would hope I would catch failures if it's a code change that broke something.

[nuclearace]

https://github.com/socketio/socket.io-client-swift/blob/master/SocketIO-MacTests/SocketBasicPacketTest.swift#L48

[vshahpledge]

Turns out I was calling the wrong method in my own code. Instead of calling this I should've been calling this from my own methods since my own method already wrapped the arguments in an array.

I apologize for my hastiness. Thanks for helping me troubleshoot this. I closed my PR since it's not necessary anymore.

[nuclearace]

Yeah the reason there are two methods is to take advantage of Swift's variadic parameters so make the api more like the JavaScript client.