Added IsSupportedAsync method.

samples/KristofferStrube.Blazor.WebAuthentication.WasmExample/Pages/Index.razor

@@ -6,6 +6,12 @@
 
 <h2>Blazor Web Authentication</h2>
 
+@if (!isSupported)
+{
+ <p>This browser feature is not support on your device.</p>
+ return;
+}
+
 <p>Here you can try create a credential from your device's native identification mechanism.</p>
 
 <button class="btn btn-success" @onclick="CreateCredential">Create Credentials</button>

samples/KristofferStrube.Blazor.WebAuthentication.WasmExample/Pages/Index.razor.cs

@@ -8,6 +8,7 @@ namespace KristofferStrube.Blazor.WebAuthentication.WasmExample.Pages;
 
 public partial class Index : ComponentBase
 {
+ private bool isSupported = false;
  private CredentialsContainer container = default!;
  private PublicKeyCredential? credential;
  private PublicKeyCredential? validatedCredential;
@@ -18,6 +19,8 @@ public partial class Index : ComponentBase
 
  protected override async Task OnInitializedAsync()
  {
+ isSupported = await CredentialsService.IsSupportedAsync();
+ if (!isSupported) return;
  container = await CredentialsService.GetCredentialsAsync();
  }
 

src/KristofferStrube.Blazor.CredentialManagement/CredentialsService.cs

@@ -1,4 +1,5 @@
-using Microsoft.JSInterop;
+using KristofferStrube.Blazor.CredentialManagement.Extensions;
+using Microsoft.JSInterop;
 
 namespace KristofferStrube.Blazor.CredentialManagement;
 
@@ -9,6 +10,12 @@ public async Task<CredentialsContainer> GetCredentialsAsync()
  IJSObjectReference jSInstance = await jSRuntime.InvokeAsync<IJSObjectReference>("navigator.credentials.valueOf");
  return new CredentialsContainer(jSRuntime, jSInstance);
  }
+
+ public async Task<bool> IsSupportedAsync()
+ {
+ IJSObjectReference helper = await jSRuntime.GetHelperAsync();
+ return await helper.InvokeAsync<bool>("isSupported");
+ }
 }
 
 

src/KristofferStrube.Blazor.CredentialManagement/wwwroot/KristofferStrube.Blazor.CredentialManagement.js

@@ -1 +1,3 @@
-export function getAttribute(object, attribute) { return object[attribute]; }
+export function getAttribute(object, attribute) { return object[attribute]; }
+
+export function isSupported() { return !(!window.PublicKeyCredential); }