Client .NET MicroFramework - XSockets/XSockets.NET-4.0 GitHub Wiki

.NET MicroFramework

The .NET MicroFramework has support for .NET MicroFramework 4.2 and 4.3

Client Setup

To get the client just get the latest package from http://nuget.org/packages/xsockets.client

The C# clients ALWAYS talk full-duplex/bi-directional communication, and just like the XSockets server this behavior has nothing to do with what OS or WebServer you are running.

How to establish a connection

Just like in the JavaScript client you can multiplex over several Controller on one connection. To get a connections just create an instance of the XSocketClient.

var conn = new XSocketClient("192.168.0.106", 4502);
conn.OnOpen += (sender, args) =>
        {
            //Connection open
        };
conn.Open();

• The first parameter is the IP of the server
• The second parameter is the port of the server

Do note that the call to Open is asynchron and you will have to wait for the OnOpen event to fire before you communicate over the connection.

How to send messages

Sending data is easy, just use the Publish method and pass in the topic, the object and the name of the controller

conn.Publish("chatmessage","Hello from NetDuino", "Chat");

The code sample above would invoke the method "Message" on the controller "Chat" with the object/data "Hello from NetDuino".

How to receive messages

When ever data is received on the NETMF client the OnMessage event will be invoked with an IMessage as parameter.

The client will receive data if there is a subscription for the specific topic, or if the server is using RPC to target clients based on state.

public static void Main()
{
    var conn = new XSocketClient("192.168.0.106", 4502);
    conn.OnOpen += (sender, args) =>
    {
            //Connection open
    };
    conn.OnMessage += ConnOnMessage;
    conn.Open();
    Thread.Sleep(Timeout.Infinite);
}

private static void ConnOnMessage(object sender, IMessage message)
{            
    //TODO: Add logic to handle the IMessage arrived
}

How to parse the message into a strongly typed object

When ever data is received on the NETMF client the OnMessage event will be invoked with an IMessage as parameter. The property "D" on the message will contain the JSON representation of the data being sent. "C" will contain the controller name and "T" will be the topic... So if we want to have some logic and parse the JSON into something useful you can do like this

private static void ConnOnMessage(object sender, IMessage message)
{            
    switch (message.C)
    {
        case "chat":
            switch (message.T)
            {
                case "chatmessage":
                    //A chatmessage was received form Chat controller, convert JSON into the ChatMessage object
                    var chatmessage = (ChatMessage)conn.Parse(message.D, typeof (ChatMessage));
                    //Do something clever :)
                    Debug.Print(chatmessage.Text);
                    break;
            }
            break;
        default:
            //Unknown controller
            break;
    }
}

How to handle connection lifetime events

The events on connection level provide information about the socket being opened/closed.

OnOpen

conn.OnOpen += (sender, args) =>
{
    //Connection open
};

OnClose

conn.OnClose += (sender, args) =>
{
    //Connection closed
};

How to handle errors

conn.OnError += (sender, args) =>
    {                
        //Error
    };

PUB/SUB

How to subscribe to a topic

Just pass in the topic and the controller to notify the server about the subscription. Do note that the client will receive data even if there is no subscription if the server-side logic uses RPC and he client is matching the requirements to where you send data.

conn.Subscribe("chatmessage","chat");

How to remove a subscription

When you no longer want to subscribe to a topic you just use the unsubscribe method to tell the server to remove the subscription.

conn.Unsubscribe("chatmessage", "chat");

How to publish to server methods from the client

Client

conn.Publish("chatmessage",new ChatModel{Text= "Hello people!","chat");

Server

//using XSockets.Core.XSocket;
//using XSockets.Core.XSocket.Helpers;

//The server will publish the message back to all clients subscribing
public void ChatMessage(ChatModel chatModel)
{
    this.PublishToAll(chatModel, "chatmessage");
}

How to set properties on the server from the client

Since we have state on all controllers in the connection and can take advantage of that we can store information server side and not send trivial things like a user-name each time we want to communicate.

Server

A simple model for a chat

public class ChatModel
{
    public string UserName {get;set;}
    public string Text {get;set;}
}

A controller where we use state to only send in text since the user-name is known.

//using XSockets.Core.XSocket;
//using XSockets.Core.XSocket.Helpers;

public class Chat : XSocketController
{
    public string UserName {get;set;}
    public void ChatMessage(ChatModel message)
    {
        message.UserName = this.UserName;
        this.InvokeToAll(message,"chatmessage");
    }
}

Client

conn.SetProperty("username","David");

Note: If the property on the controller is an Enum use the SetEnum method instead

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