This epic posting on MVC helped me better understand the pattern, and all the variants that have flowed outward from the original design. One interesting observation is that the earlier designs used Views primarily as output-only, and Controllers primarily as input-only, and as a consequence the Controller was the one true path for getting data into the Model.
But with browser forms, input and output are tightly intermingled. The View takes care of input and output. Something else has primary responsibility for mediating the data flow to and from the model–and that something has been called a Presenter. This yields the MVP pattern.
The terminology gets confusing quickly, but roughly
XForms Instance == MVP Model
XForms Model == MVP Presenter
XForms User Interface == MVP View
It’s not wrong to associate XForms with MVC–the term has become so blurry that it’s easy to lump variants like MVP into the same bucket. But to the extent that it makes sense to talk about more specific patterns, maybe we should be calling the XForms design pattern MVP instead of MVC. Comments? Criticism? Fire away below. -m
