Strongly-typed T4MVC Action/ActionLink

问题:

I've been using T4MVC (FYI: v2.6.62) for quite some time, and I've been slowly moving over our code to this way of working (less reliance on magic strings).

But I've had to stop because, for some reason, T4MVC is unable to translate objects into urls, and only seems to be able to work on primitive types (int/string/etc).

Here is an example:

Route breakdown:

/MyController/MyAction/{Number}/{SomeText}

Class:

namespace MyNamespace
{
  public class MyClass
  {
    public int Number { get; set; }
    public string SomeText { get; set; }
  }
}

Controller:

public class MyController
{
  public virtual ActionResult MyAction(MyClass myClass)
  {
    return View();
  }
}

View:

<%= Html.Action(
  T4MVC.MyController.Actions.MyAction(
    new MyClass()
    {
      Number = 1,
      SomeText = "ABC"
    }
 ) %>

The end result is this:

/MyController/MyAction?myClass=MyNamespace.MyClass

and not

/MyController/MyAction/1/ABC

Does anyone else have this problem? Are T4MVC urls like this available?

Question also asked at the ASP.NET Forum.

回答1:

Update (10/11/2012): the recently added support for Model Unbinders (see section 3.1 in the doc) should hopefully cover a lot of these cases.

Original answer:

Copying my reply from the forum thread:

Hmmm, I don't think this has come up yet. Maybe in most cases that people have Action methods that take an object, the object's values come from posted form data, rather than being passed on the URL? In such scenario, the question doesn't arise.

I think in theory T4MVC could be changed to support this. It would just need to promote all the object's top level properties as route values rather than try to use the object itself (obviously, the current behavior is bogus, and is a result of just calling ToString() blindly).

Have others run into this and think it's worth addressing?

回答2:

If I've understood the problem correctly then the following syntax should allow you to work around the problem.

<%= Html.ActionLink("test", MVC.MyController.MyAction().AddRouteValues(new MyClass() { Number = 5, SomeText = "Hello" })) %>

I think the answer to make the syntax nicer would be to wrap each non value type parameter in a RouteValueDictionary in each generated action result method

Edit: (Response to comment as not enough chars)

Ah ok I managed to recreate the simple example above using this method to give: /MyController/MyAction/5/Hello as the url. I'm not quite sure how nested complex types would pan out in practice. You could use some recursion to dive down the into the top-level object and reflect over the values to add them but then you open up a new set of issues, such as how to cope with a child property name that is identical to the parent property name. This seems like it could be a complex problem to solve, in a manner that would work for everyone. Perhaps some kind of adapter pattern would be most useful to transform a complex object into route values. In the simplest case this might be to declare an extension method ToRouteDictionary that acts on your complex type and transforms it using your knowledge of how it should work. Just thinking out loud as I'm obviously not aware of your use cases