Angular 2 TypeScript using SignalR

问题:

I'm trying to set up an Angular 2 application to use Microsoft's SignalR. I've been following this tutorial, which although it's good I don't like the fact that jQuery and SignalR are loaded into the application via script tags in the index.html file and also the fact that both libraries do not use their respective Type Definitions.

So with that in mind I've been trying to include jQuery and SignalR in my application using node modules and the respective Type Definitions. I've searched the correct type definition files to use through Microsoft's TypeSearch.

I'm only including jQuery in my application because of SignalR's dependency on jQuery.

jQuery

I first started with installing the jQuery module in my application which I've had to add in the Webpack configuration as well. After this was set up I'm being faced with a "conflict" issue because of Protractor. This is described on Aurelia JS Rocks' website. Although it suggests uninstalling the protractor typings I tried our another solution for now described in this answer. I don't know if this is the best solution.

SignalR

With regards to SignalR I'm a bit stuck - so far it seems there's no "official" node module provided for SignalR. I'm not sure whether I should include Microsoft's SignalR Javascript Library by downloading the file and including it in my application.

The issue is that I have installed the Type Definitions for SignalR. But now I'm not sure how to go about actually using SignalR since when I type $ or jQuery I'm not being suggested .connections for example - which makes sense as this is not part of the jQuery library.

I'm sure that I might be misunderstanding something with regards to getting it "set up". What's the best way to go about using SignalR in an Angular2 TypeScript application?

回答1:

Here's a startup code you can use.

C#

//create an interface that contains definition of client side methods
public interface IClient
{
    void messageReceived(string msg);
}

//create your Hub class that contains implementation of client methods
public class ChatHub : Hub<IClient>
{
    public void sendMessage(string msg)
    {
        //log the incoming message here to confirm that its received

        //send back same message with DateTime
        Clients.All.messageReceived("Message received at: " + DateTime.Now.ToString());
    }
}

HTML

Add reference to script files of jQuery and signalR.

<script src="path/to/jquery.min.js"></script>
<script src="path/to/jquery.signalR.min.js"></script>

<!--this is the default path where SignalR generates its JS files so you don't need to change it.-->
<script src="~/signalr/hubs"></script>

JS

You need to install TypeScript definition file for SignalR and jQuery. If you're using TypeScript 2, you don't need to add reference to index.d.ts file while using it. Just install the typings using following commands.

npm install --save @types/jquery
npm install --save @types/signalr

With all the setup done, you can write a simple TypeScript class to handle the logic for sending and receiving messages.

export class MessageService {
    //signalR connection reference
    private connection: SignalR;

    //signalR proxy reference
    private proxy: SignalR.Hub.Proxy;


    constructor() {
        //initialize connection
        this.connection = $.connection;

        //to create proxy give your hub class name as parameter. IMPORTANT: notice that I followed camel casing in giving class name
        this.proxy = $.connection.hub.createHubProxy('chatHub');

        //define a callback method for proxy
        this.proxy.on('messageReceived', (latestMsg) => this.onMessageReceived(latestMsg));

        this.connection.hub.start();
    }

    private onMessageReceived(latestMsg: string) {
        console.log('New message received: ' + latestMsg);
    }

    //method for sending message
    broadcastMessage(msg: string) {
        //invoke method by its name using proxy 
        this.proxy.invoke('sendMessage', msg);
    }
}

I'm using the above code, obviously modified to my needs, and it works fine.

回答2:

you can try

npm install ng2-signalr --save

you can read the setup instructions here,
There is also a link to a working demo.