Receiving multiple SignalRMessageAction parameters on a AspNetCore client

Bubba Jones 211

I have the following server side azure function which I am able to invoke from an ASP.NET client.

    [Function("SendToGroup")]
    [SignalROutput(HubName = "serverless", ConnectionStringSetting = "SignalRConnection")]
    public static async Task<SignalRMessageAction> SendToGroup([SignalRTrigger("serverless", "messages", "SendToGroup", "groupName", "message")] SignalRInvocationContext invocationContext, string groupName, string message)
    {
        return new SignalRMessageAction("joinedGroupMessage")
        {
            GroupName = groupName,
            Arguments = new object[] { $"Joined group {groupName}." }
        };
    }

However I am not able to receive the above returned SignalRMessageAction in my AspNetCore client once the above has been executed. I am currently using the following AspNetCore client side code.

        //  This syntax compiles but is not correct; it does not trigger when the server returns the 
        //  SignalRMessageAction
        _connection.On<string, string>("joinedGroupMessage", (groupName, groupMessage) =>
        {
            chatMessages.Text = groupName;
            chatMessagesX.Text = groupMessage;
        });

I am able to invoke other SignalRMessageAction's from the server on my client as long as they only send back 1 parameter. So my SignalR setup and upstream settings is working. My issue is with the above syntax which I am not doing right apparantly.

JasonPan - MSFT 4,476 Reputation points Microsoft Vendor

2023-04-12T08:50:16.7733333+00:00

Hi @Bubba Jones,

ASP.NET Core SignalR is not compatible with ASP.NET SignalR.

As you mentioned, you use asp.net core create the azure function, right? And you client is based on ASP.NET ? Okey, try to create a ASP.NET Core Client, then test.

Please check the Nuget Packages in this github link, make sure you are using the right SDK inside your client application.

Best Regards

Jason
Bubba Jones 211 Reputation points

2023-04-13T06:47:05.7+00:00

I using an AspNetCore client and have corrected my OP accordingly. I also edited my OP to mention that my client does work when I return only one SignalRMessageAction parameter from the server. Its when I return multiple SignalRMessageAction parameters from the server which my client does not capture.
Bubba Jones 211 Reputation points

2023-04-14T12:15:11.4466667+00:00

@Liangying Wei I am invoking your help on this thread as you have previously been very helpful in pinpointing the AspNetCore client side code I needed to use in my previous threads.

JasonPan - MSFT 4,476 Microsoft Vendor

Hi @Bubba Jones, I am still working on this thread. And I also contact Liangying, I think she will reply you mext monday. Since the environment issue on my side, I am unable to test below code. I think we should use Multiple output bindings to implement this requirement. I am not sure whether it could work. I will test it when I have the environment. Hope it can inspire you.

        [Function("SendToGroup")]
        [SignalROutput(HubName = "Hub")]
        public static async Task<MyOutputType> SendToGroup( string groupName, string message)
        {
            MyOutputType output = new MyOutputType() { };
            output.Name = "Hub";
            List<SignalRMessageAction> Response = new List<SignalRMessageAction>();
            for (int i = 0; i < 10; i++)
            {
                SignalRMessageAction s = new SignalRMessageAction("joinedGroupMessage")
                {
                    GroupName = groupName,
                    Arguments = new object[] { $"Test User - "+i+" Joined group {groupName}." }
                };
                output.Response.Add(s);
            }
            return output;
        }
        public class MyOutputType
        {
            [SignalROutput(HubName = "Hub")]
            public string Name { get; set; }

            public List<SignalRMessageAction> Response { get; set; }
        }

Thanks for your patience.

Best Regards

Jason

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Accepted answer

Liangying Wei 756 Microsoft Employee

Oh I see you are using local emulator. So now your client is "user1" right? So you need to update your client code to use user1, _groupData.UserId = "user1"

UserId is actually inside ConnectionContext so you can also update your AddToGroup code to:

[Function("AddToGroup")]
        [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")]
        //  string userId is NULL here
        public static async Task<SignalRGroupAction> AddToGroup([SignalRTrigger("serverless", "messages", "AddToGroup", "groupName")] SignalRInvocationContext invocationContext, string groupName)
        {
            //  This does not seem to add the user to the group.  Note I do not have any on the client side for this.  Not sure if I need one?
            return new SignalRGroupAction(SignalRGroupActionType.Add)
            {
                GroupName = groupName,
                UserId = invocationContext.UserId
            };
        }

And update your client code to await _connection.InvokeAsync("AddToGroup", _groupData.GroupName)

1 additional answer

Liangying Wei 756 Reputation points Microsoft Employee

2023-04-17T01:54:49.4766667+00:00
Hi @Bubba Jones , if you specify GroupName in your SignalRMessageAction, it means that you are going to send the message to a group, invoking client method joinedGroupMessage with arguments defined in Arguments, there is only 1 object in the Arguments array however your client is expecting 2 parameters, try changing the client code to:

_connection.On<string, string>("joinedGroupMessage", (groupMessage) => { chatMessagesX.Text = groupMessage; });
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Bubba Jones 211 Reputation points

2023-04-17T18:00:52.5666667+00:00

@Liangying Wei

Thank you for your response.

Before I continue, to clarify, I have been trying to implement an ASPNetCore client to invoke the functions found in this server side documentation. Note that in that documenation, HttpTriggers are being used wheras I am using SignalRTrigger's to invoke my server side functions. I am not sure if this is important or not.

Having re looked at my code, I realize I missed a step; I did not add the client to the group. I have now done so. However alhtough the server side functions are being invoked I am still not receiving the SignalRMessageAction despite modifying it as per your suggestion. To avoid going back and forth too much I am now posting the full client and server side code. In it I added comments as to what works and does not work. Full server side code (observe the comments):

// This gets invoked though maybe I should be using an HttpTrigger to invoke this function [Function("AddToGroup")] [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")] public static async Task<SignalRGroupAction> AddToGroup([SignalRTrigger("serverless", "messages", "AddToGroup", "groupName", "message")] SignalRInvocationContext invocationContext, string groupName, string userId) { return new SignalRGroupAction(SignalRGroupActionType.Add) { GroupName = groupName, UserId = "1234" }; } // This gets invoked via my clients InvokeAsync // but the the client does NOT receive the returned SignalRMessageAction: [Function("SendToGroup")] [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")] public static async Task<SignalRMessageAction> SendToGroup([SignalRTrigger("serverless", "messages", "SendToGroup", "groupName", "message")] SignalRInvocationContext invocationContext, string groupName, string message) { // This maye not be received on the client end. return new SignalRMessageAction("joinedGroupMessage") { GroupName = groupName, Arguments = new object[] { $"Sent {message} to group {groupName}." } }; }

Full client side code. Please observe the comments;

namespace MauiSignalRSample; public partial class MainPage : ContentPage { private readonly HubConnection _connection; private string _url = "http://localhost:7071/api"; public class GroupData { public string GroupName { get; set; } public string UserId { get; set; } } static GroupData _groupData = new GroupData(); public MainPage() { InitializeComponent(); _connection = new HubConnectionBuilder().WithUrl(_url).Build(); _groupData.UserId = Guid.NewGuid().ToString(); _groupData.GroupName = "GroupName1"; // This does not trigger _connection.On<string>("joinedGroupMessage", (groupMessage) => { chatMessagesX.Text = groupMessage; }); Task.Run(() => { Dispatcher.Dispatch(async () => await _connection.StartAsync()); }); } private async void AddToGroupClicked(object sender, EventArgs e) { // This invokes the server side function succesfully. Should I be using an HttpClient // and using a PostAsync? await _connection.InvokeAsync("AddToGroup", _groupData.GroupName, _groupData.UserId); } private async void OnSendClicked(object sender, EventArgs e) { // This invokes the server side function succesfully. However when the server returns // the SignalRMessageAction, the "joinedGroupMessage" (see MainPage() above is not triggered await _connection.InvokeAsync("SendToGroup", _groupData.GroupName, "message1"); } }

If you do not see anything amiss I will try modifying my client side code to use an HttpClient.

Liangying Wei 756 Reputation points Microsoft Employee

2023-04-18T03:27:06.33+00:00

Triggers are how you invoke the Azure Function, use SignalRTrigger if you use hubConnection.InvokeAsync to trigger the Azure Function method, and use HttpTrigger if you use HTTPClient to trigger the Azure Function method. Since your client uses _connection.InvokeAsync to invoke the Azure Function method, using SignalRTrigger looks great.

I see your logic that when AddToGroupClicked you invoke AddToGroup method in Azure Function with parameter _groupData.GroupName and_groupData.UserId. Looks like a typo in your Azure Function AddToGroup method that userId is not used. Try updating 1234 to userId to see if it works.

Bubba Jones 211 Reputation points

2023-04-21T06:39:06.11+00:00

@Liangying Wei

Thanks for the response; I was aware of that hardcoded "1234" assignment - I intentionally put it there because for some reason when I invoke that server function with a valid string value for _groupData.UserId it becomes null when it reaches the server. This is another issue I need to resolve and I am not sure why this is happening.

// _groupData.UserId has valid string data here
await _connection.InvokeAsync("AddToGroup", _groupData.GroupName, _groupData.UserId);

However when it reaches the server, the last parameter "userId" is null:

[Function("AddToGroup")] [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")] // string userId is NULL here public static async Task<SignalRGroupAction> AddToGroup([SignalRTrigger("serverless", "messages", "AddToGroup", "groupName", "message")] SignalRInvocationContext invocationContext, string groupName, string userId) { return new SignalRGroupAction(SignalRGroupActionType.Add) { GroupName = groupName, UserId = userId }; }

Liangying Wei 756 Reputation points Microsoft Employee

2023-04-21T09:37:59.6466667+00:00

The parameter name should match.

Change the parameter in SignalRTrigger from message to userId

[Function("AddToGroup")] [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")] // string userId is NULL here public static async Task<SignalRGroupAction> AddToGroup([SignalRTrigger("serverless", "messages", "AddToGroup", "groupName", "userId")] SignalRInvocationContext invocationContext, string groupName, string userId) { return new SignalRGroupAction(SignalRGroupActionType.Add) { GroupName = groupName, UserId = userId }; }

Bubba Jones 211 Reputation points

2023-04-21T13:05:33.79+00:00

@Liangying Wei

Well done that solved that problem. I never payed attention to matching the parameter names with the string names. With that working, I then invoked my SendToGroup function below:

[Function("SendToGroup")] [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")] public static async Task<SignalRMessageAction> SendToGroup([SignalRTrigger("serverless", "messages", "SendToGroup", "groupName", "message")] SignalRInvocationContext invocationContext, string groupName, string message) { // This maye not be received on the client end. return new SignalRMessageAction("joinedGroupMessage") { // If I comment out the GroupName argument below the client WILL receive the SignalRMessageAction result GroupName = groupName, Arguments = new object[] { $"Sent {message} to group {groupName}." } }; }

Although the above was invoked, the "On" event on the client side still did not trigger.

// This does not trigger _connection.On<string>("joinedGroupMessage", (groupMessage) => { chatMessages.Text = groupMessage; });

I tried removing the GroupName argument from the SendToGroup server function (see comment in first block of code) - then it worked. There may is something amiss with the AddToGroup function on the server side (below), in that it does not actually add the user to the group, despite now receiving valid parameters:

public static async Task<SignalRGroupAction> AddToGroup([SignalRTrigger("serverless", "messages", "AddToGroup", "groupName", "userId")] SignalRInvocationContext invocationContext, string groupName, string userId) { // This does not seem to add the user to the group. Note I do not have an On event on the client side for this. Do I need one? return new SignalRGroupAction(SignalRGroupActionType.Add) { GroupName = groupName, UserId = userId }; }

I am wondering if I need an "On" event on the client side to receive this response. I will tinker with that and if there is any improvement I will repost.

Liangying Wei 756 Reputation points Microsoft Employee

2023-04-23T02:08:11.6033333+00:00

userId needs to be added in negotiate so that your client is considered as this user when connecting to Azure SignalR. Under the hood, it is the sub claim in the JWT access token. So it is not assigned on your client-side but on your Function side. For example, set userId as user1 in your negotiate method:

[Function("Negotiate")] public static string Negotiate([HttpTrigger(AuthorizationLevel.Anonymous)] HttpRequestData req, [SignalRConnectionInfoInput(HubName = "serverless", UserId = "user1")] string connectionInfo) { // The serialization of the connection info object is done by the framework. It should be camel case. The SignalR client respects the camel case response only. return connectionInfo; }

You can read the userId from the headers using function's {headers.xxx} syntax. Here shows how to integrate it with function's auth middleware: https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-signalr-service-input?tabs=isolated-process&pivots=programming-language-csharp#authenticated-tokens

Bubba Jones 211 Reputation points

2023-04-24T12:07:41.55+00:00

@Liangying Wei

Thank you for the response. I have modified my Negotiate function as per your specification. The connectionInfo variable contained this:

"url": "http://localhost:8888/client/?hub=serverless", "accessToken": "eyJhbGciOiJIUzI1NiIsImtpZCI6IjIxMzQ3NDAyNTgiLCJ0eXAiOiJKV1QifQ.eyJhc3JzLnMudWlkIjoidXNlcjEiLCJuYmYiOjE2ODIzMzc1MDAsImV4cCI6MTY4MjM0MTEwMCwiaWF0IjoxNjgyMzM3NTAwLCJhdWQiOiJodHRwOi8vbG9jYWxob3N0L2NsaWVudC8_aHViPXNlcnZlcmxlc3MifQ.9WRE9UXbpBBp6u-Tuar2KnURAs9xj335wen4oI3WJz0"

Do I need to capture this on the client side and use it for input on the server to add to the correct group? Unfortunately It is still not clear to me what I need to do (client or server) in order to get my SignalRMessageAction("joinedGroupMessage") to trigger.

Liangying Wei 756 Reputation points Microsoft Employee

2023-04-25T03:10:07.3466667+00:00

The URL should be the AzureSignalR endpoint e.g. "https://xxxx.service.signalr.net" instead of "http://localhost:8888", have you set AzureSignalRConnectionString in your function app?

Basically, the client side works as a normal SignalR client, your current client-side code looks great, the only thing needs to change is to move the UserId to your server side into the negotiate method. The SignalR client, when it connects, it first sends a "/negotiate" HTTP request to your Azure Function, that's why "Negotiate" is an HTTP trigger function. And the negotiate request returns a response containing the Azure SignalR URL and access token needed, when the SignalR client receives the response, it starts the connection with the Azure SignalR service, all these steps are implemented inside the SignalR client library. Here contains details about the workflow https://learn.microsoft.com/en-us/azure/azure-signalr/signalr-concept-internals After the persistent connection is established between your client and Azure SIgnalR service, when client invokes SignalR method, the traffic goes through Azure SignalR to your Azure Function, such traffic uses SignalR protocol and that's why the AddToGroup methods in your Azure Function uses SignalRTrigger.

Bubba Jones 211 Reputation points

2023-04-26T08:39:05.44+00:00

@Liangying Wei

I think there has been a misunderstanding; I have a fully configured and functional locally hosted SignalR application that uses the SignalR emulator. All my server functions are being invoked via the client, including my negotiate function. None of this would be possible if my core setup, including my AzureSignalRConnectionString or SignalR service was not configured correctly. Maybe there is something explicit that requires a real SignalR service (via Azure)? If its not the case I am all good setup wise. As for the issue at hand, I have modified the Negotiate function as per your specifications by adding the UserId = "user1" parameter. As a reminder of where we left off, here is my full code (server and client)

Server side code (includes modified Negotiate function):

public class Functions { [Function("Negotiate")] public static string Negotiate([HttpTrigger(AuthorizationLevel.Anonymous)] HttpRequestData req, [SignalRConnectionInfoInput(HubName = "serverless", UserId = "user1")] string connectionInfo) { return connectionInfo; } // This gets invoked though I don't believe that the SignalRGroupAction(SignalRGroupActionType.Add) below actually adds the user to the group [Function("AddToGroup")] [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")] // string userId is NULL here public static async Task<SignalRGroupAction> AddToGroup([SignalRTrigger("serverless", "messages", "AddToGroup", "groupName", "userId")] SignalRInvocationContext invocationContext, string groupName, string userId) { // This does not seem to add the user to the group. Note I do not have any on the client side for this. Not sure if I need one? return new SignalRGroupAction(SignalRGroupActionType.Add) { GroupName = groupName, UserId = userId }; } [Function("SendToGroup")] [SignalROutput(HubName = "serverless", ConnectionStringSetting = "AzureSignalRConnectionString")] public static async Task<SignalRMessageAction> SendToGroup([SignalRTrigger("serverless", "messages", "SendToGroup", "groupName", "message")] SignalRInvocationContext invocationContext, string groupName, string message) { // The the client does NOT receive this returned SignalRMessageAction (see cient code below): // _connection.On<string>("joinedGroupMessage", (groupMessage) => { chatMessagesX.Text = groupMessage; }); return new SignalRMessageAction("joinedGroupMessage") { // If I comment out the GroupName argument below the client WILL received the SignalRMessageAction result GroupName = groupName, Arguments = new object[] { $"Sent {message} to group {groupName}." } }; } }

Client side code - when I run it I first invoke AddToGroup then SendToGroup (in that specific order):

public partial class MainPage : ContentPage { private readonly HubConnection _connection; private string _url = "http://localhost:7071/api"; public class GroupData { public string GroupName { get; set; } public string UserId { get; set; } } static GroupData _groupData = new GroupData(); public MainPage() { InitializeComponent(); _connection = new HubConnectionBuilder().WithUrl(_url).Build(); _groupData.UserId = Guid.NewGuid().ToString(); _groupData.GroupName = "GroupName1"; // The server SignalRMessageAction("joinedGroupMessage") which is invoked via SendToGroup does not trigger this _connection.On<string>("joinedGroupMessage", (groupMessage) => { chatMessages.Text = groupMessage; }); // This successfully invokes the server side Negotiate function Task.Run(() => { Dispatcher.Dispatch(async () => await _connection.StartAsync()); }); } private async void AddToGroupClicked(object sender, EventArgs e) { // This successfully invokes the server side function succesfully await _connection.InvokeAsync("AddToGroup", _groupData.GroupName, _groupData.UserId); } private async void OnSendClicked(object sender, EventArgs e) { // This invokes the server side function succesfully. However when the server returns // the SignalRMessageAction, the "joinedGroupMessage" (see MainPage() above is not triggered await _connection.InvokeAsync("SendToGroup", _groupData.GroupName, "message1"); } }

Again, I have a fully configured local environment, all the functions in the client above are successfully invoking their server side counterparts. The outstanding issue is that server SendToGroup function fails to trigger the _connection.On "joinGroupMessage" event above. This is likely because something is amiss server side wise.

Bubba Jones 211 Reputation points

2023-04-28T07:07:03.2733333+00:00

@Liangying Wei

With the above post, you have resolved the core issue which was that I was unable to add the user to a group on the server side and send messages to the group that the user belonged to.

Now everything works - there is unfortunately one caveat remaining; The Negotiate function below hardcodes "user1" into the server via the negotiate function and obliges the client to also use "user1" to add the user to the group and receive messages from that group.

[Function("Negotiate")] public static string Negotiate([HttpTrigger(AuthorizationLevel.Anonymous)] HttpRequestData req, [SignalRConnectionInfoInput(HubName = "serverless", UserId = "user1")] string connectionInfo) { return connectionInfo; }

So the question remains, how can I make the value of "UserId" that is passed into the server via the "Negotiate" function below dynamic? I tried this approach according to this article:

[Function("Negotiate")] public static string Negotiate([HttpTrigger(AuthorizationLevel.Anonymous)] HttpRequestData req, [SignalRConnectionInfoInput(HubName = "serverless", UserId = "{headers.x-ms-client-principal-id}")] string connectionInfo) { return connectionInfo; }

And got the following runtime error when the Negotiate function was invoked:

Error while accessing 'x-ms-client-principal-id': property doesn't exist.

Liangying Wei 756 Reputation points Microsoft Employee

2023-04-28T08:13:10.5+00:00

x-ms-client-principal-id is the header if you are using App Service Authentication, here contains steps and explanations: https://learn.microsoft.com/en-us/azure/azure-signalr/signalr-tutorial-authenticate-azure-functions#deploy-to-azure-and-enable-authentication

Bubba Jones 211 Reputation points

2023-04-28T12:32:56.1666667+00:00

@Liangying Wei

Before we continue down this path can you confirm that App Service Authentication that uses the x-ms-client-principal-id parameter is a requirement to being able to pass in dynamic values for userId via the negotiate function?

Bubba Jones 211 Reputation points

2023-05-03T15:29:34.79+00:00

@Liangying Wei

Just pinging you to get an answer on my previous comment. I will in the meanwhile try to set up my azure environment.

Liangying Wei 756 Reputation points Microsoft Employee

2023-05-04T03:10:06.76+00:00

App Service Authentication is not a requirement but a well-supported and recommended way in Azure Function, check here for explanations https://learn.microsoft.com/en-us/azure/app-service/configure-authentication-oauth-tokens

If you want to test dynamically set userId locally, you can pass the userId in your negotiate query string, for example,

In your client, append ?userid=user1 to your _url

In your Negotiate method, read userId from the query using [SignalRConnectionInfoInput(HubName = "Hub", UserId = "{query.userid}")]

Bubba Jones 211 Reputation points

2023-05-08T10:35:53.01+00:00

@Liangying Wei Thank you for your latest post. It solved my final problem with getting the whole client / server setup working. Considering that you resolved the core issue (getting the signalR trigger to be invoked on the client side) with your post on Apr 27, 2023, 5:58 AM, I would like to accept that answer so we can close this thread. For clarity, I have upvoted all your replies that helped me resolve the issues I was facing. It is unfortunate I cannot accept them all.

MuthuKumaranMurugaachari-MSFT 22,236 Reputation points

2023-05-08T15:01:23.83+00:00

Bubba Jones Thanks for the engagement and converted the comment as answer. Liangying Wei appreciate the help!
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Receiving multiple SignalRMessageAction parameters on a AspNetCore client

1 additional answer