Extending razor components - Blazor #1148

4 Answer(s)

• 

  0

  mladen.macanovic created 4 years ago

  This is how Blazor works.

  You cannot inherit razor code part. You can only inherit from the class type. What I mean my that? Well, you must know what razor file represents in Blazor component. Basically, it is a RenderFragment that is rendering (in pseudo code).

  override void Render()
  {
     // render elements
  }
  

  Once compiled it is just a regular Render method. That is why you can't inherit it. You must write the implementation again.

  Regerding you problem with OnInitializedAsync, I think you can do that. Instead of inherting both .razor and .cs, inherit only the class part.

  using Microsoft.AspNetCore.Components;
  using System;
  using System.Threading.Tasks;
  using Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout;
  using Volo.Abp.DependencyInjection;
  
  namespace TVD_Holdings_Ltd.AvalancheOCP.Blazor.Components.ApplicationLayout
  {
      [ExposeServices(typeof(DefaultLayout))]
      [Dependency(ReplaceServices = true)]
      public class DefaultLayoutExtension : DefaultLayout
      {
  
          [Inject] IConfiguration Configuration { get; set; }
          [Inject] IAlertManager _alertManager { get; set; }
          private HubConnection hubConnection;
  
          protected override async Task OnInitializedAsync()
          {
              // Do something
          }
      }
  }
  

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  2
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  0

  Leonardo.Willrich created 4 years ago

  Hi mladen.macanovic,

  Thank you for your answer. I got your point and I am rewriting the razor part as well.

  I've tried your suggestion with MainHeader component, only inheriting the class part, but that doesn't work, see below:

  Code:

  using System;
  using System.Threading.Tasks;
  using Volo.Abp.AspNetCore.Components.Web.LeptonTheme.Components.ApplicationLayout.MainHeader;
  using Volo.Abp.DependencyInjection;
  
  namespace TVD_Holdings_Ltd.AvalancheOCP.Blazor.Components.Layout
  {
      [ExposeServices(typeof(MainHeader))]
      [Dependency(ReplaceServices = true)]
      public class MainHeaderExtension : MainHeader
      {
          protected override async Task OnInitializedAsync()
          {
              Console.WriteLine("MainHeader Init");
          }
      }
  }
  

  Error:

  My only concern overriding the .razor and .razor.cs is updating the framework and getting conflit or missing some changes due to overriden files.

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• 

  0

  mladen.macanovic created 4 years ago

  I tried the same logic in Blazorise code and it working fine. Might be something in ABP that is interfering maybe. I will need to investigate more and get back to you.

  In the meantime just use both .razor and .razor.cs. While not the pretiest, it is a working solution.

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• 

  0

  Leonardo.Willrich created 4 years ago

  Hi mladen,

  Please, don't prioritize that! I have a workaround and I end up adding one more component to the layout anyway to show a modal message. I'll close this thread, I appreciate your help and explanation.

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  1