UHF - Unified Hypermedia DSL: Type-Safe Reactive Backend Driven Web Framework

[fmcarvalho]

Description below leverages the terminology intrinsic to the Model-View-Controller (MVC) pattern.

We propose a unified model that shares signals between backend and frontend through a strongly-typed definition of Signal<T>, part of the HtmlFlow API.

A controller that instantiates a Signal may automatically mount a new route that emits a DataStar patch signal whenever the signal updates, e.g., route /controller-events.

That signal instance can be part of the controller’s state and passed to a HtmlFlow view via, for example: someView.render(signal).

We may provide a new type of view that, whenever it receives a signal as its model, automatically subscribes to the corresponding SSE route. For example: data-init="@get('/controller-events')"

Interaction scheme

Controller
   |
   | --- new ---> Signal<T>
   |                |
   |                | --- mounts ---> SSE Route (/controller-events)
   |
   v
Browser --- HTTP GET ---> Controller
                    |
                    v
          View includes data-init="@get('/controller-events')"

Browser --- POST/PUT/... ---> Controller
                    |
                    v
                Updates Signal
                    |
                    v
               Emits SSE event /controller-events --- updates --->  Browser View through Datastar