Customize OpenIddict Client Error Display

Question

How can you customize the error messages provided by the Openiddict client. The errors in the sample app are text only, and break the user experience.

Steps to replicate:

1. Clone the openiddict-samples repository git clone https://github.com/openiddict/openiddict-samples.git
2. Start the Velusia.Client project (I use Visual Studio)
3. Browse to https://localhost:44338/callback/login/local

This displays a text only response:

error:missing_token
error_description:The security token is missing.
error_uri:https://documentation.openiddict.com/errors/ID2000

How do you customize this response to show "proper" MVC view with an error message (similar to https://localhost:44338/error)?

I understand this is the correct response - I just want to customize how it is displayed to the user.

Answer 1

I'm exploring solutions for this issue. I've devised a potential approach involving registering an event handler for the client within the Startup.cs, but I'm not entirely certain if it's the correct method. Any insights or suggestions would be appreciated.

                options.AddEventHandler<ProcessErrorContext>(builder =>
                {
                    builder.UseInlineHandler(context =>
                    {
                        if(context != null)
                        {
                            if(context.Error != null)
                            {
                                throw new Exception(context.Error);
                            }
                        }
   
                        return default;
                    });
                });

Answer 2

The approach I'd recommend is to use ASP.NET Core's native status code pages middleware to render error pages: OpenIddict natively supports it and you can enable it quite easily:

services.AddOpenIddict()
    .AddClient(options =>
    {
        options.UseAspNetCore()
               .EnableStatusCodePagesIntegration();
    });

See https://github.com/openiddict/openiddict-samples/tree/dev/samples/Velusia/Velusia.Client for an example.