Last I checked, Borland's widget library (their "Visual Component Library", or VCL) was, like React, View-only. The idea was that the view is the hard part and you, the coder, can choose how to structure the rest of your application yourself.

So sure you can put all data management right inside your Delphi form, and plenty of coders did this. You can do that with React too. But larger applications often chose to go with MVC, where the appropriate fields inside the VCL components were updated triggered by changes in the model.

It's nearly entirely the same model. The view classes (Delphi components, forms, etc) can render (by setting attributes on widgets) and have event handlers (eg onButtonClick) which in turn invoke the Controller, which makes appropriate data changes in the model.

Nothing in Delphi enforces this, but it matches really well. Thne only big thing they missed was something akin to a Virtual DOM and shouldComponentUpdate, making figuring out which fields to update when cumbersome. But there's been plenty older solutions to this problem (such as damage/repair).

It's probably evolved a bit, but when Delphi had big momentum most developers used data-bound components that updated directly from DB view queries and whatnot.

There were complex components that did transformations on the data for reporting or complex grid displays, etc, but generally you didn't see an abstract formal model behind forms/views. If you did model outside the DB, you did it in such a way that the model looked like a database table or query (subclassing abstract DB proxy components the VCL gave you) and used components directly bound to that.

So, I guess in MVC terms, what you had was a form implementing View logic with components directly working from DB or DB-like data, and controller code behind the form doing event-driven manipulation. The controller code could hook data events too, and in that way reacted to "model" changes as well, but the "model" was actually hidden in DB bindings and components. For any model business logic more complex than you could handle this way, middleware was usually pushed.

This may have progressed since the early 2000s when I lost track of Delphi, but the idea of directly-bound display components was typical of the dominant DB-driven 4GLs of the time, including Powerbuilder and VB.