The value of the 'Access-Control-Allow-Credentials' header in the response is '' which must be 'true' when the request's credentials mode is 'include'

Question

User665712185 posted

I have a api app in Azure, i want to add real time notofication, in my client im using angularjs and my code looks like this

var connection = null;
    this.initialize = function () {
        connection = $.hubConnection("http://name.azurewebsites.net/signalr/hubs", { useDefaultPath: false });
        this.proxy = connection.createHubProxy('myHub');
        
       connection.start().done(function () {
            console.log("started");
        }).fail(function (result) {
            console.log(result);
        });
    };

And in my server im using owin startup, and i have a it confiqured like this

 app.Map("/signalr", map =>
            {
                map.UseCors(CorsOptions.AllowAll);
                var hubConfiguration = new HubConfiguration {};
                hubConfiguration.EnableJSONP = true;
                map.RunSignalR(hubConfiguration);
                
            });

and i get this error

XMLHttpRequest cannot load http://name.azurewebsites.net/signalr/hubs/negotiate?clientProtocol=1.5&connectionData=%5B%5D&_=1501957673711. The value of the 'Access-Control-Allow-Credentials' header in the response is '' which must be 'true' when the request's credentials mode is 'include'. Origin 'http://localhost:35609' is therefore not allowed access. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute.

Answer 1

User-707554951 posted

Hi Hero1v1,

As far as I know, The Access-Control-Allow-Credentials response header indicates whether or not the response to the request can be exposed to the page. It can be exposed when the true value is returned.

Credentials are cookies, authorization headers or TLS client certificates.

When you include one of Credentials above Access-Control-Allow-Credentials must be set to true:

Related link:

https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS

https://developer.mozilla.org/en-US/docs/Web/API/Request/credentials

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Credentials

Best Regards

Cathy