RemoteAttribute?[Answered] RSS

• • Reply
  MichaelDBang

  Member

  13 Points

  64 Posts

  RemoteAttribute?

  Aug 13, 2020 06:55 AM|MichaelDBang|LINK

  Looking to do this:

  https://stackoverflow.com/questions/54186153/remote-validation-in-asp-net-core-razor-pages

  But in Blazor Server-side, and preferably without JQuery.

  Possible?

• • Reply
  Mikesdotnett...

  All-Star

  194882 Points

  28101 Posts

  Moderator

  Re: RemoteAttribute?

  Aug 17, 2020 02:56 PM|Mikesdotnetting|LINK

  The RemoteAttribute depends on jQuery via the unobtrusive ajax library. There is nothing comparable in Blazor. You just need to wire up an event handler to the onchange event of an input that calls a service to perform validation as required. Something like this:

  <input value="@emailAddress" @onchange=@(e => validate(e)) />
  @code {
      string emailAddress { get; set; }
      async Task validate(ChangeEventArgs e)
      {
          if (await client.GetFromJsonAsync<bool>("/api/email/validate?emailAddress=" + e.Value))
          {
              emailAddress = e.Value.ToString();
          }
      }
  }

  The method at api/email/validate will contain the logic that ensures the value is valid, returning a bool either way. 

  ASP.NET Tutorials | Learn Entity Framework Core | Learn Razor Pages | Learn Dapper
• • Reply
  MichaelDBang

  Member

  13 Points

  64 Posts

  Re: RemoteAttribute?

  Aug 17, 2020 03:13 PM|MichaelDBang|LINK

  Thank you for the reply (and the bad news ), @Mikesdotnetting!  Obviously not a cool as adding an attribute and allowing things to "just work" but it will put me in the right direction.  I will probably encapsulate it in a component and use that instead.

• • Reply
  bruce (sqlwo...

  All-Star

  58484 Points

  15806 Posts

  Re: RemoteAttribute?

  Aug 17, 2020 07:49 PM|bruce (sqlwork.com)|LINK

  Blazor uses data attribute validation, so you can create your own custom validators. But currently there is no async validation, so they should not be used for remote validation.

  bruce (sqlwork.com)