How to select a DynamicField template in Dynamic Data based on runtime data?

Question

I know it is possible to pass a dictionary of compile time parameters to the dynamic filter controls by using the UIHint attribute on the models. Unfortunately this is not enough in our case.

For example, consider this model:

public class Device
{
    public string Unit {get; set;}
    public string Name {get; set;}
}

An 'Unit' is a segregating property in our models. One unit does not interfere with another. At the same time, multiple units coexist in the same server, and are accessed by different clients, with different needs.

Ideally, I wanted to load a different dynamic field when the unit has a certain value.

Consider the case where I have two units:

• unit1: Requires no customization. Loads the [default] dynamic templates from the DynamicData\FieldTemplates folder

• unit2: Clients who are in "unit2" requested a different way to show the device Name for instance, thus we create a custom folder for the unit and change the Text.ascx template there.

The structure would look like this:

Notice that there are now two 'Text' field templates. The idea is to use the one inside the 'unit2' folder whenever the instance I'm manipulating has 'unit2' as it's Unit property value. The controls in the root FieldTemplates folder would now act as a fallback mechanism for when the folders and controls do not exist for a given unit value.

These folders would be created after the project has been deployed and the units created, which shouldn't be a problem at all from what I can see. The only files that would be present in the original project are the "default" templates.

Initially I thought about creating my own FieldTemplateFactory implementation and attaching it to the MetaModel, but it doesn't seem to get access to the actual instance of the object, only it's MetaColumn. After that, I decided to take a look at how the DynamicField and DynamicControl controls were implemented, but couldn't find any extension point that would do what I want.

I've seen people do something similar, but with entire page templates. By using custom routes, one can make that work. In my case though, since we are talking Field Templates, that doesn't apply.

Is there another way I should be approaching this? Can I somehow base the decision of template loading on the value of a property inside the object? Is there some other, perhaps simpler, strategy to show different templates for different units?

Answer 1

you can maybe do this through the route but not the live data as the Field Template is selected before the data is bound.