This documentation includes information about the io-client, that MooMoo uses to communicate with the server.
The io-client is an Object that has all the information you need to interact with MooMoo servers. Lets go through all of them.
This property is the WebSocket connection to the server. It is a WebSocket object.
This property is a boolean that indicates if the client is connected to the server. by default it is false obviously.
This property is the uniqe id of the socket. It gets set when the client connects to the server, and stays the same until the client disconnects.
This property is a function that takes 3 arguments:
address: The URL, that the client should connect to. click here how to create a valid URL.callback: A function that gets called when the client is connected or when an error occurs. It handles errors and tells the client if it is connected or not.events: An Object that contains all the events that the client should listen to.
Everything that happens inside of the connect function, is in a try/catch block. If an error occurs, the callback function gets called with the error as the first argument.
Inside of the try/catch block, the client created a new WebSocket, sets the socket property to the new WebSocket, and sets the connected property to true.
After that, it configures the binaryType property of the WebSocket to arraybuffer.
Then, it sets the socket.onmessage property to a function that gets called when a message is received.
This Function takes in 1 argument, which is a MessageEvent object. This Object gets converted into a new Uint8Array and decoded with the msgpack library.
It now has a encoded packet, which is an Array with the following structure:
0: The type of the packet.1: The data of the packet.
More information about the packet structure can be found in the protocol documentation.
Now it checks if the packet type is io_init, which is the inital packet that the server send to the client. It includes one information, which is the socketId.
If the packet type is not io_init, it calls the proper event handler with the data of the packet.
var type = parsed[0];
var data = parsed[1];
if (type == "io-init") {
this.socketId = data[0];
} else {
events[type].apply(undefined, data);
}Now after that, it sets the socket.onopen property to a function that gets called when the connection is opened.
When the connection is opened, it calls the callback and sets this.connected to true.
After that, it sets the socket.onclose property to a function that gets called when the connection is closed.
When the connection is closed, it calls the callback with either Disconnected or Invalid Connection as the first argument depending if event.code is 4001.
Now, it sets the socket.onerror property to a function that gets called when an error occurs. This function calls the callback with Socket Error as the first argument.
The send function takes an Array as its first and only argument.
The Array has the following structure:
0: The type of the packet.1: The data of the packet.
First the Array gets extracted by calling it with Array.slice.
var data = Array.prototype.slice.call(arguments, 1);After that, it gets converted into binary data with the msgpack library. The binary data then gets sent to the server.
This function returns if the socket is ready to send data.
socketReady: function() {
return (this.socket && this.connected);
},This function closes the socket.