Extending CommonViewModel to include additional properties

Question

I have a very simple problem: Depending on what environment I deploy Identity Server 3, I want to have the logon page to display a different image. The image source location is defined in the web.config and transformed depending on build configuration.

I'm overriding the partial _login.html to allow the image to be displayed, but I cannot find out how to (easily) pass into the view a variable that defines this configuration variable.

I believe that this is possible by using a CustomViewService shown here : http://identityserver.github.io/Documentation/docs/advanced/customizingViews.html But I would like to know whether there is an easier way of passing a variable into a view without having to create a CustomViewService.

Would it be possible to extend the CommonViewModel and get Identity Server 3 to resolve this at run time ? The ExtendedCommonViewModel would be extremely simple :

public class ExtendedCommonViewModel : CommonViewModel
{
  public string ImageLocation
  {
     get { return ConfigurationManager.AppSettings["ImageLocation"].ToString(); }
  }
}

And then use it in the _login.html view as <img src="{ImageLocation}" />

I realise that this would still need to be parsed into the Replace function in the default view service, and so this is where this idea falls down : https://github.com/IdentityServer/IdentityServer3/blob/master/source/Core/Services/DefaultViewService/DefaultViewService.cs

So to reiterate; Is there an easy way to pass a variable into an overridden partial view in Identity Server 3 without having to create a CustomViewService ?

Edit :

Additional - I can see a hack of a solution by passing the variable in as a Scripts parameter on the DefaultViewServiceOptions but this seems too hacky.

Would is be possible to extend the DefaultViewServiceOptions and add a custom dictionary that can contain custom model parameters that could then be used in the view. This seems like the best solution, but would mean changing the DefaultViewService

score 0 · Answer 1 · answered Aug 08 '16 at 10:51

You're best off creating your own IViewService implementation.

It's possible to inherit the DefaultViewService and only override what you need to change.

In your case, I think you can just create a CustomLoginViewModel inheriting from LoginViewModel with whatever data you need.

public class CustomViewService : DefaultViewService 
{
   ...    
    public override Task<Stream> Login(LoginViewModel model, SignInMessage message)
    {
        var customVm = new CustomViewModel { MyProp = "123" };
        return Render(customVm, LoginView);
    }
}

Extending CommonViewModel to include additional properties

1 Answers1