Extending an ABP controller

[sonicmouse]

I know you can override an ABP controller: https://docs.abp.io/en/abp/latest/Customizing-Application-Modules-Overriding-Services#example-overriding-a-controller

But, how would you add an endpoint to the overridden controller? I have tried adding an endpoint and I can't hit it with Postman and it doesn't show up in swagger. For example:

[Dependency(ReplaceServices = true)]
[ExposeServices(typeof(IdentityUserController))]
public class MyIdentityUserController : IdentityUserController
{
    public MyIdentityUserController(IIdentityUserAppService userAppService) : base(userAppService)
    {
    }

    public override Task<PagedResultDto<IdentityUserDto>> GetListAsync(GetIdentityUsersInput input)
    {
        // this works fine and it gets hit
        return base.GetListAsync(input);
    }

    [HttpGet, Route("mymethod")]
    public Task<string> MyMethod()
    {
        return Task.FromResult("Doesn't work");
    }
}

How can I accomplish this?

[olicooper]

Duplicate: #7698

[sonicmouse]

Duplicate: #7698

That sure isn't a duplicate. The solution provided doesn't solve the issue. The solution provided implements a visual kludge in swagger by using the same Route property as IdentityUserController. It doesn't extend the service controller.

[RemoteService(Name = IdentityRemoteServiceConsts.RemoteServiceName)]
[Area("identity")]
[ControllerName("User")]
[Route("api/identity/users")]
[ExposeServices(typeof(MyIdentityUserController))]
public class MyIdentityUserController : AbpController, IApplicationService, IRemoteService
{
    [HttpGet("my-method")]
    public Task<string> MyMethod()
    {
        return Task.FromResult("Works");
    }
}

How is that extending IdentityUserController in any way? How does that inherit IdentityUserController methods, properties and base logic?

As a matter of fact, i don't see IdentityUserController anywhere in that code.

[olicooper]

Both questions ask about extending an existing abp controller to add a new method. The only difference is that the other question also says they want to override an existing method. I would consider this a duplicate.

The only thing missing from that code to allow you to 'extend' functionality is a constructor with the AppService for you to access the available app service methods. this will appear the same to any user of the system.

public MyIdentityUserController(IIdentityUserAppService userAppService)
{
}

public Task<??> MyAdditionalMethod(SomeInput input)
{
    return userAppService.DoSomething(input);
}

I wouldn't call it 'kludge', it's not like using magic strings, or having 100 parameters for a method. I don't believe it has any effect on performance, nor is it a hack. I also believe it does solve the issue of extending the available API methods. May I ask in what tangible way this approach is not feasible for your needs? I am open to a better solution but I don't believe one exists - though I would be interested if one does 👍 😄 Please also refer to my latest comment on the other issue: #7698 (comment)

[sonicmouse]

What if i wanted to IIdentityUserAppService in conjunction with public virtual Task<IdentityUserDto> FindByEmailAsync(string email) that IdentityUserController implements?

How do I do that?

What I am saying is: you are simply creating a new controller. That's it. Your fix doesn't have anything to with inheritance, which is what we want to accomplish. We want to inherit from IdentityUserController not create a new class and throw it in the same category as IdentityUserController.

It seems ABP breaks a very basic inheritance pattern that OOP gives us. It seems. Which I highly doubt. So there is something we must be missing, which is why I opened an issue.

I don't know how else explain it.

[olicooper]

Yep okay no problem, I will see if it is possible to do it the way you describe when I am next able to. I am curious too. Until then I think we will have to wait for a reply from ABP on the matter. I still think it is a duplicate though 😄

[sonicmouse]

The issue you linked talked about swagger not working -- This isn't a swagger issue since you can't hit the new endpoint via Postman. I could just remove the mention of swagger in the question and the issue is still relevant.

[Ultre00]

The linked issue started as a different issue but in the end turned out to be the exact same problem as you described in this ticket. I started the GitHub issue before I created that stack overflow issue. Your question sums up the exact same problem I am facing as of this moment. Also looking for a clean way to extend an existing controller with one or more functions and still being able to override in the same extended class.

[maliming]

hi @sonicmouse

• Your ABP Framework version.
• Steps needed to reproduce the problem.

[Ultre00]

@maliming it is with version 3.3.2. I created a project to reproduce the issue. Created an empty project with the cli from 3.1.2 (3.3.2 didn't work anymore). Then I manually upgraded to 3.3.2 (also because abp update -v 3.3.2 for some reason isn't working anymore today).

https://github.com/Ultre00/AbpExtendingControllers/blob/11c7cb832cfe80db9a91945786a36de528d51396/src/AbpExtendingControllers.Web/Controllers/MyAccountAcontroller.cs#L22

That is the only class I added. When you call the register from postman the overridden function gets called. The my-function endpoint always returns a 404. Also not visible in swagger

[maliming]

@Ultre00

Have you seen this? #5269 (comment)

[Ultre00]

@maliming yes I have seen it. The overriding part isn't the problem. That does actually work. It is adding a new method that doesn't work

[olicooper]

I have had a look at the source code and I can see that derived controllers are removed when the application starts up, which will likely stop the additional actions in the derived controllers being registered.

abp/framework/src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/Conventions/AbpServiceConvention.cs

Lines 74 to 103 in 739db98

	protected virtual void RemoveDuplicateControllers(ApplicationModel application)
	{
	var derivedControllerModels = new List<ControllerModel>();
	foreach (var controllerModel in application.Controllers)
	{
	if (!controllerModel.ControllerType.IsDefined(typeof(ExposeServicesAttribute), false))
	{
	continue;
	}
	if (Options.IgnoredControllersOnModelExclusion.Contains(controllerModel.ControllerType))
	{
	continue;
	}
	var baseControllerTypes = controllerModel.ControllerType
	.GetBaseClasses(typeof(Controller), includeObject: false)
	.Where(t => !t.IsAbstract)
	.ToArray();
	if (baseControllerTypes.Length > 0)
	{
	derivedControllerModels.Add(controllerModel);
	Logger.LogInformation($"Removing the controller {controllerModel.ControllerType.AssemblyQualifiedName} from the application model since it replaces the controller(s): {baseControllerTypes.Select(c => c.AssemblyQualifiedName).JoinAsString(", ")}");
	}
	}
	application.Controllers.RemoveAll(derivedControllerModels);
	}

The log:

[INF] Removing the controller MyApp.Controllers.MyIdentityUserController, MyApp.HttpApi.Host, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null from the application model since it replaces the controller(s): Volo.Abp.Identity.IdentityUserController, Volo.Abp.Identity.HttpApi, Version=3.3.2.0, Culture=neutral, PublicKeyToken=null

Not sure how this would be fixed though.

[maliming]

See #7766