Use of a proxy for Blazor web API calls

[MartijnCarolTREFF]

Description

Is this documentation absolute? This example 'll cause CORS problems According to

• https://www.twilio.com/docs/sendgrid/for-developers/sending-email/cors)
• https://stackoverflow.com/questions/74879455/cant-send-email-with-sendgrid-and-blazor-webassembly

I should create an API to be able to use sendgrid to email.

Page URL

https://learn.microsoft.com/en-us/aspnet/core/security/authentication/accconfirm?view=aspnetcore-9.0&tabs=visual-studio

Content source URL

https://github.com/dotnet/AspNetCore.Docs/blob/main/aspnetcore/security/authentication/accconfirm.md

Document ID

98e7aacb-2a01-d581-9b03-bfef2893163e

Article author

@Rick-Anderson

Metadata

• ID: fe1bea60-d173-f6d2-3559-b147699e295a
• Service: aspnet-core
• Sub-service: security

Related Issues

[guardrex]

@Rick-Anderson ... I'll take this one for the Blazor node.

Correct, @MartijnCarolTREFF ... With Blazor WASM, use your own web API or a proxy service that can forward the request. I just hit this a few weeks ago myself because I have a tool that we use to help us create links to API articles that is a Blazor WASM app with a web API call to a MS endpoint. Because the WASM app can't make the call directly, I use a proxy service. I choose to go with CloudFlare's https://corsproxy.io/. You can see my implementation here ...

https://github.com/dotnet/blazor-samples/blob/main/BlazorWebAssemblyXrefGenerator/Pages/Home.razor#L162-L165

Note how my call to $"https://learn.microsoft.com/en-us{result.Url}?view={dotNetVersion}" is encoded and sent as $"https://corsproxy.io/?{urlEncodedRequestUrl}". That's a good example of how to make a request like that. We're using it as a free service at the moment because this is just a test/debug scenario for us. BTW ... that app is cobbled together at the moment to solve some rendering problems that I need to work further on. Don't look too closely at the rest of it! 🙈😆 It's definitely a WIP 🛠 at the moment. It works, but it has a classic RexHack!™ in it 😆. However, that use of the proxy service is a good example there, so you can look into that approach if it will work for you.

If that's not going to work for your scenario, then Yes! ... roll your own backend web API to make the calls that you need to make.

Also note that this isn't really the best article for Blazor WASM with account confirmation and PW recovery. See .........

https://learn.microsoft.com/en-us/aspnet/core/blazor/security/webassembly/standalone-with-identity/account-confirmation-and-password-recovery?view=aspnetcore-9.0

... which is part of that three-article series on Blazor WASM+Identity in that node of security articles. There's another article after that on 2FA/TOTP. The overview of that set describes the WASM+Identity sample app setup and config.

This is such a good point that you're raising that I would like to add a Blazor section on it to the WASM coverage. Leave this issue open. It will close automatically later when the PR that I create merges.