Cotacol Web App

An attempt to learn Blazor, by setting up a Cotacol web site

This web site has been published to https://www.cotacol.eu and can be used to register and link your Strava profile against the Cotacol Hunting backend. This web site shares the same backend as the iOS app (and the Android app that is coming)

Troubleshooting & links

Identity login

1. Set up razor server app, with individual identiy

2. Scaffolded two pages, based on this article: https://andrewlock.net/customising-aspnetcore-identity-without-editing-the-pagemodel/

   • Account.Login, which enables the customization of the actual login page dotnet aspnet-codegenerator identity -dc CotacolApp.Data.ApplicationDbContext --files "Account.Login"
   • Account.ExternalLogin, which enables the customization of the actual strava page dotnet aspnet-codegenerator identity -dc CotacolApp.Data.ApplicationDbContext --files "Account.ExternalLogin"

3. Add OAuth nuget package: Microsoft.AspNetCore.Authentication.OAuth

4. Update Startup.cs to include Strava login

   services.AddAuthentication().AddOAuth("Strava",
       oAuthOptions =>
       {
           oAuthOptions.ClientId = "myappid"; 
           oAuthOptions.ClientSecret = "myclientsecret";
           oAuthOptions.Scope.Clear();        
           oAuthOptions.Scope.Add("read");
           oAuthOptions.CallbackPath = "/profile"; 
           oAuthOptions.AuthorizationEndpoint = "https://www.strava.com/oauth/authorize";
           oAuthOptions.TokenEndpoint = "https://www.strava.com/api/v3/oauth/token";
           oAuthOptions.SignInScheme = IdentityConstants.ExternalScheme;
           oAuthOptions.Events = new OAuthEvents()
           {
               OnRemoteFailure = loginFailureHandler =>
               {
                   Console.WriteLine("Remote Error");
                   Console.WriteLine(loginFailureHandler.Failure.Message);
                   return Task.FromResult(0);
               }, 
               OnAccessDenied = handler =>
               {
                   Console.WriteLine(handler.Response.StatusCode);
                   return Task.FromResult(0);
               }
           };
       });

5. Issue when logging on : var info = await _signInManager.GetExternalLoginInfoAsync(); returns null. Similar issue found here : https://stackoverflow.com/questions/40227643/signinmanager-getexternallogininfoasync-always-returns-null-with-open-id-to-a

6. Issue when getting null in GetExternalLoginInfoAsync : https://stackoverflow.com/questions/46158462/instagram-oauth-getexternallogininfoasync-always-returns-null-in-net-core-2-0/55970100

Access to tokens

It is important to get access to the OAuth Tokens, since they have to be passed to the API Backend, where they will be refreshed on a daily basis. The SaveTokens property does not seem to work, initially, so here are some posts/threads:

1. Access tokens in asp.net core: https://blog.maartenballiauw.be/post/2020/01/13/making-api-calls-using-the-access-token-and-refresh-token-from-an-aspnet-core-authentication-handler.html

2. https://docs.microsoft.com/en-us/aspnet/core/security/authentication/social/additional-claims?view=aspnetcore-5.0

InvalidOperationException: No authenticationScheme was specified, and there was no DefaultAuthenticateScheme found. The default schemes can be set using either AddAuthentication(string defaultScheme) or AddAuthentication(Action configureOptions).