Adding Context Items for services

I implemented a custom client filter:

	public class AppendIdentifierFilter: IClientFilter
	{
		public async ValueTask<ResponseContext> SendAsync(RequestContext context, Func<RequestContext, ValueTask<ResponseContext>> next)
		{
			context.Items.Add("test", "foo);
			return await next(context);
		}
	}

and tried to access it in my service on the server-side:

public async UnaryResult<Nil> Test()
		{
			Logger.Info($"we have the items {string.Join(", ", Context.Items.Keys)}");
....

But the items dictionary appears to be empty.

To initialize the service I used the following way:

MagicOnionClient.Create<ITestService>(_channel, new IClientFilter[]
				{
					new AppendIdentifierFilter(_identifier), 
				});

From the documentation, I could not figure out what part was still missing.

Thank you for any help

[mayuki]

Sorry. Certainly the example code does not work properly. To add a header to the request, use WithHeaders method.

var client = MagicOnionClient.Create<IMyService>(channel)
    .WithHeaders(new Metadata
    {
        { "x-foo", "Bar" }
    });

await client.MethodBazAsync();

[mayuki]

There are no sharings between RequestContext (Client) and CallContext (Server). For example, you can use CallContext.Items for sharing values between MagicOnionFilters and a service method in the server-side per call.

If you want to pass the key-values with request from client to server, use RequestContext.CallOptions.Headers (Client) and CallContext.RequestHeaders (Server).

// Server: Client filter
public class MyClientFilter : IClientFilter
{
    public async ValueTask<ResponseContext> SendAsync(RequestContext context, Func<RequestContext, ValueTask<ResponseContext>> next)
    {
        context.CallOptions.Headers.Add("x-foo", "Bar");
        return await next(context);
    }
}

// Server: Service filter
public class MyFilterAttribute : MagicOnionFilterAttribute
{
    public override async ValueTask Invoke(ServiceContext context, Func<ServiceContext, ValueTask> next)
    {
        var foo = context.CallContext.RequestHeaders.Get("x-foo");
        await next(context);
    }
}