implementing model binder to bind a certain data format - asp.net-mvc

Question

i want to model bind this this data that is sent from the client
tag[15-d] : Little Owl
tag[19-a] : Merlin
name : value
into IEnumrable<AutoCompleteItem>
public class AutoCompleteItem
{
public string Key { get; set; }
public string Value { get; set; }
}
for example
Key = 15-d
Value = Little Owl
i don't know how to implement my own model binder in this scenario , any solution ?

Answer 1

Here is a model binder that I did for you and does what you want. It by no means complete (no validation, no error checking etc), but it can kick start you. One thing I particularly dislike is that the ModelBinder directly accesses the form collection instead of using the ValueProvider of the context, but the latter doesn't let you get all bindable values.
public class AutoCompleteItemModelBinder : IModelBinder
{
// Normally we would use bindingContext.ValueProvider here, but it doesn't let us
// do pattern matching.
public object BindModel (ControllerContext controllerContext, ModelBindingContext bindingContext)
{
string pattern = #"tag\[(?<Key>.*)\]";
if (!String.IsNullOrWhiteSpace (bindingContext.ModelName))
pattern = bindingContext.ModelName + "." + pattern;
IEnumerable<string> matchedInputNames =
controllerContext.HttpContext.Request.Form.AllKeys.Where(inputName => Regex.IsMatch(inputName, pattern, RegexOptions.IgnoreCase));
return matchedInputNames.Select (inputName =>
new AutoCompleteItem {
Value = controllerContext.HttpContext.Request.Form[inputName],
Key = Regex.Match(inputName, pattern).Groups["Key"].Value
}).ToList();
}
}
Here is a sample action that uses it:
[HttpPost]
public void TestModelBinder ([ModelBinder(typeof(AutoCompleteItemModelBinder))]
IList<AutoCompleteItem> items)
{
}
And a sample view. Note the "items." prefix - it's the Model Name (you can drop it depending on how you submit this list of items:
#using (Html.BeginForm ("TestModelBinder", "Home")) {
<input type="text" name="items.tag[15-d]" value="Little Owl" />
<input type="text" name="items.tag[19-a]" value="Merlin" />
<input type="submit" value="Submit" />
}
If you have questions - add a comment and I will expand this answer.

Answer 2

You should just be able to name your fields key[0], value[0] (1,2,3 etc) and it should bind automatically since these are just strings. If you need to customize this for some reason - still name your fields key[0] value[0] (then 1,2,3 etc) and do exactly as specified here:
ASP.NET MVC - Custom model binder able to process arrays