ASP.NET MVC: What if your model is just a Dictionary?

Question

(I'm new to MVC).

In my application I don't have a model in the sense of a class with properties. Oh no it's much simpler: my users basically fill in a bunch of string values for various keys setup elsewhere in the system (the keys are arbitrary and not known ahead of time, thus no pre-coded class)¹.

My "model" thus is just:

Dictionary<string, string>

Pretty simple.

As I understand it model binding, html helpers, model state, validation summaries all rely on reflection of an arbitrary class' properties. But can they just use the key/values in my dictionary instead?

For example, can I have:

<label for="Name">Name:</label>
<%= Html.TextBox("Name") %>
<%= Html.ValidationMessage("Name", "*") %>

and:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Create(Dictionary<string, string> valuesEntered)
{            
    // ...
}

and have MVC use the "Name" key/value as found in my Dictionary<string, string> "model" to do all its behind-the-scenes magic? (MVC 1.0 preferrably, but please shed some light if this is better addressed in 2.0 as I'd still like to know)?

---

_{1: sounds silly I'm sure. It's for a reporting app, where the "keys" are the report parameter names and the "values" are the values the report will run with.}

Answer 1

The default model binder in MVC 1.0 can bind to a dictionary as long as it uses the magic form field identifiers 'dictionaryName[index].key' and 'dictionaryName[index].value', where dictionaryName is the name of your dictionary parameter, and index is a 0-based sequential number. Typically the 'key' value will be a hidden field, and the 'value' value is your text field. In your example:

<%= Html.Hidden("valuesEntered[0].key", "Name") %>
<%= Html.TextBox("valuesEntered[0].value") %>
<%= Html.ValidationMessage("valuesEntered[0].value", "*") %>

As I understand it, binding to dictionaries is different in MVC 2.