Strong typed tag helpers

[artiomchi]

The tag helpers are working as expected and the mvc-action currently supports both synchronous and async actions. The issue is that these two types of actions have a different return type (IActionResult vs Task<IActionResult>)

In the tag helper code I've set the type of that attribute as object to allow both types of methods to be accepted, and am type checking when generating the url, but that doesn't seem ideal.

I've added additional "fake" attributes with the same name, which gives me the benefit of showing the other accepted action result types in intellisense, which is my current workaround.

Options that I came up with so far are:

1. Leave it as is. The value type of the attribute is object, but it accepts all actions in a consistent way, and the intellisense provides users with hints on data types
2. Generate separate attributes for synchronous and async actions.
   For example mvc-action and mvc-action-async
3. Only support IActionResult in the tag helpers. For async actions, users will have to invoke .Result

<a mvc-action="MVC.Home.Index().Result">Async Index</a>

I'm interested to know what others thing would work best

[artiomchi]

This would be easily solved if TagHelpers only populated the property of the supported type. As you can see above, the IntelliSense is aware of all three properties, but only the first one is populated. If I remove the Object one, then the second one will receive the values, and will throw an exception for Task<> values.

There's an issue for the aspnet team requesting support for this, so we might leave it as is until they implement it, meaning no changes to our api down the line: aspnet/Razor#237