Push4711

Need a really easy way to push typed events via SignalR? This one might be interesting for you...

Usage / Setup

It's easy to setup and use this library. Let's walk through the process step by step while observing an example.

Sender

Preparation: Install NuGet package Push4711.Sender to your project.

Add SignalR and Push4711 to your IoC container by adding them to the service collection at startup:

using Microsoft.Extensions.DependencyInjection;
using Push4711.Sender;

//...

public void ConfigureServices(IServiceCollection services)
{
    //... - You probably are adding some other stuff here

    services.AddSignalR();
    services.AddPushNotificationService();
}

You are good to go! You can now obtain an IPushNotificationService instance from you IoC container and start sending push notifications - either broadcasting them or sending them to only a specific receiver (specified by the SignalR connection id):

IPushNotificationService pushNotificationService; //Obtain this from the IoC container

pushNotificationService.BroadcastNotification(new YourDataClassOrDomainEvent 
{ 
    SomeRandomProperty = 4711, 
    SomeRandomOtherProperty = "4712"
});

To enable make this work, your transmitted data class -in this case YourDataClassOrDomainEvent- just needs to be serializable. For serialization System.Text.Json is being used; so in most cases it should just work. To continue with our example we can use this code:

using System;

public class YourDataClassOrDomainEvent
{
    public int SomeRandomProperty { get;set; }

    public string SomeRandomOtherProperty { get;set; }
}

Receiver

Preparation: Install NuGet package Push4711.Receiver to your project.

The receiver needs a little bit more configuration effort. To be functional, the receiver needs a configuration object implementing the IPushNotificationReceiverConfiguration interface. You can either implement something yourself (in case you need some kind of dynamic configuration) or just use the included PushNotificationReceiverConfiguration class. You don't even need to instantiate it yourself, as you just can just set the whole thing up by this setup method (which adds everything needed to the IoC container):

using Push4711.Receiver;

//...

public void ConfigureServices(IServiceCollection services)
{
    //... - You probably are adding some other stuff here

    services.Add("https://my-random-hostname:4711/notificationHub/", "MyProject.CommonCode");
}

This example code will expect your server to receive push data from at https://my-random-hostname:4711/notificationHub/ and will search for the type definitions of received events by default in MyProject.CommonCode. Considering the sample sender setup above, your class YourDataClassOrDomainEvent should be within a project named MyProject.CommonCode, whose assembly needs to be accessible by the receiver code. If your notification classes are within an assembly shared by sender and receiver, you should just be fine. You can also bypass this behaviour - see chapter "Advanced" for more information on this topic.

You are now ready to consume the received events! Just get a IPushNotificationHandler instance from the IoC container and call the Subscribe method. Provide the type of the data you're expecting to receive -in our previous example YourDataClassOrDomainEvent- and a callback with it as parameter, which will be executed upon data arrival. That's it.

When subscribing, you will get DataNotificationSubscription object in return as kind of token for your subscription. The subscription can be cancelled by calling the CancelSubscription method of the IPushNotificationHandler instance and passing the obtained DataNotificationSubscription object. As an alternative, you can also cause the subscription to be cancelled by simply disposing your DataNotificationSubscription object.

If you for example want to update a page within a Blazor project with the push notifications, your code could possibly look like this:

@page "/sample"
@using Push4711.Receiver
@inject IPushNotificationHandler NotificationHandler
@implements IDisposable

<h1>SamplePage</h1>

<p>This is a really basic sample page. SomeRandomProperty: @myDataObject.SomeRandomProperty / SomeRandomOtherProperty: @myDataObject.SomeRandomOtherProperty</p>

@code {
    private YourDataClassOrDomainEvent myDataObject;
    private DataNotificationSubscription dataPushUpdateSubscription;

    protected override async Task OnInitializedAsync()
    {
        this.dataPushUpdateSubscription = this.NotificationHandler.Subscribe<YourDataClassOrDomainEvent>(this.HandlePushUpdateData);
    }

    private void HandlePushUpdateData(YourDataClassOrDomainEvent pushDataUpdate)
    {
        this.myDataObject = pushDataUpdate;
        base.StateHasChanged();
    }

    public void Dispose()
    {
        this.dataPushUpdateSubscription?.Dispose();
    }
}

Of course you can also use more "traditional" code to consume your incoming push notification data:

using System;
using Push4711.Receiver;

public class BusinessLogicPushDataConsumer : IDisposable
{
    private readonly DataNotificationSubscription _pushUpdateSubscription;

    public BusinessLogicPushDataConsumer(IPushNotificationHandler notificationHandler)
    {
        this._pushUpdateSubscription = notificationHandler.Subscribe<YourDataClassOrDomainEvent>(this.HandlePushUpdate);
    }

    private void HandlePushUpdate(YourDataClassOrDomainEvent pushUpdateData)
    {
        //TODO: Do something useful with your received data!
    }

    public void Dispose()
    {
        this._pushUpdateSubscription?.Dispose();
    }
}

Advanced usage

Coming soon...

Specifying full type identifier string / Manually creating the push events

Coming soon...

Using topics

Coming soon...

Manually cancelling subscriptions (instead of disposing)

Coming soon...

Technical remarks

Coming soon...

Contribution

Feedback, issues and/or merge requests are always welcome! :)