Modules should convert values on setInput and setOutput

[hinerm]

Modules should probably use the ConvertService when setting their input or output values. Currently they do not, which forces higher up code to decide if conversion should be done or not (e.g. in the WidgetModel).

this would require:

• AbstractModule and perhaps Module itself should be made Contextual, instead of just CommandModule.
• Expose an @Parameter ConvertService to modules
• Update overriding setInput and setOutput to also convert values.

[hinerm]

This is probably the right thing to do, but we should also consider how Module values are being set. For example, in the WidgetModel, as soon as a choice is made the value is attached to the model. This seems like it may be premature if the user is still in the act of choosing an option until they have confirmed a dialog. It seems like the transfer of a value to the Module in this case should happen in the processResults method instead. Other use cases may be similar (and there of course may be reasons for the current behavior I'm not aware of)...

[ctrueden]

There is one reason to associate the selected value with the module instance, even before the dialog is confirmed: callbacks. The input harvesting framework calls each parameter's callback method whenever that parameter value changes. This allows, e.g., width and/or height fields to be automatically altered when an aspectRatio boolean is toggled on. So while I agree that in some cases it might be inefficient to convert a value every time it changes, I think it is by far the most straightforward to implement and understand, and I'd be reluctant to do anything cleverer than that.