This is a two part piece on working with Interfaces in MVC via the Html.EditorFor helper.
The first part - “Display” - just covers one of those things I tried on the off chance, and was rather surprised that it worked right out of the box.
In the second part I’ll have a look at the next step of the process - binding these interfaces back to their models.
For reference, I’m working with MVC4, in VS 2012 For Web. I think this will also work in MVC3 at least.
For a slightly messy user interface I’m working on, I wanted to be able to have a Model that holds a list of classes that implement an interface.
There is a possibility that all the classes might not be the same, and I was concerned that I was going to end up with a messy
switch statement in my View that called the right Partial depending on which class I found in the list, and that this switch might need to be maintained on an on-going basis.
On the off chance I tried outputting the list using
EditorFor and an EditorTemplate for each of the types that might occur in the list.
I was expecting either that, most likely,
EditorFor wouldn’t like to be passed a
List<> declared against an interface, or that it might complain that the concrete model type didn’t resolve to a single type in the list.
Instead, just outputting the List using a single
EditorFor turned out to automatically select the right EditorTemplate for each item in the list with no further intervention.
This simple example shows a what happens:
Lets define some simple models:
In the controller we make a simple list of these models:
We need EditorTemplates for the models:
The main View is as minimal as can be:
Finally, when we put all this together we get the following in the browser:
Here I’ve shown that it’s easy to use a combination of EditorFor and Interfaces to vary the output of a list to the page. Nothing earth-shattering in setting it up, but it is one of those things that’s nice to have working right out of the box.
In Part 2 I’ll have a look at the next step of the process - binding these interfaces back to their models.