stube

stube is a personal research project — a Clojure exploration of an idea about web frameworks that has been pulling at me for nearly twenty years: that page boundaries should be invisible, that HTML should be data in the host language, and that one component should be able to call another like a function and read its answer like a return value. The lineage is Seaside and the UCW family; the wire is Datastar; the implementation is a small effect kernel over plain Clojure maps, written hand-in-hand with LLM assistants. The rationale page has the full story.

Components are plain data. The conversation is a value. The server does the rendering; the browser just morphs the patches.

(require '[dev.zeko.stube.core :as s])

(s/defcomponent :demo/counter
  :init   (fn [_] {:n 0})
  :render (fn [self]
            [:div (s/root-attrs self)
             [:button (s/on self :click :as :dec) "−"]
             [:span " " (:n self) " "]
             [:button (s/on self :click :as :inc) "+"]])
  :handle (fn [self {:keys [event]}]
            (case event
              :inc (update self :n inc)
              :dec (update self :n dec))))

(s/mount! "/" :demo/counter)
(s/start! {:port 8080})

Open http://localhost:8080/. That's a counter — one component, no JavaScript, no client/server contract to manage by hand.

The real payoff shows up when one component calls another:

(s/defcomponent :demo/save-or-cancel
  :render (fn [self]
            [:div (s/root-attrs self)
             [:button (s/on self :click :as :save)   "Save"]
             [:button (s/on self :click :as :cancel) "Cancel"]])
  :handle (fn [self {:keys [event]}]
            (case event
              :save   [(s/call :ui/confirm {:question "Save changes?"} :on-confirmed)]
              :cancel [(s/answer :cancelled)]))
  :on-confirmed
  (fn [self yes?]
    [(s/answer (if yes? :saved :cancelled))]))

(s/confirm "Save changes?") is a component. Calling it stacks it on top of the current frame. When the user clicks Yes or No it answers back — and your :on-confirmed resume fires with the value. The component doing the asking never thinks about callbacks, promises, or modal state machines: it just calls a question and reads the answer. That is the Seaside model, rebuilt for 2026.

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Documentation

Tutorial	Build a real app, step by step. Start here.
API reference	Every public function in dev.zeko.stube.core.
Internals	How the kernel, conversation and effects fit together.
Rationale	Why stube exists. Seaside, the uncommon web, and where the model came from.

The design notes that drove the implementation live in docs/v2.md and docs/v2_1.md.

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What stube explores

A handful of long-standing ideas, combined now that the missing pieces finally exist:

• Components are values. A component is a map of pure functions. The kernel is one multimethod and a fold. No class hierarchy, no lifecycle interface, no special object identity.

• Effects are values. Handlers return [self' effects]. Every interaction is inspectable at the REPL with no server running — (s/replay :my/root [{:event :submit}]) walks the same code path the browser does.

• Call and answer. Components call other components like functions and read the answer like return values. Wizards, confirmations, in-place editors, login flows: one primitive. This is the Seaside idea, rebuilt.

• Linear flows. (s/defflow ...) writes what would have been a state machine as straight-line Clojure with (s/await child-embed) for suspend points. The macro compiles down to a regular component using cloroutine.

• Datastar over the wire. SSE patches, morph by id. The only client-side code is the Datastar runtime itself. Two-way bindings through s/bind; events through s/on.

• Persistent history. Every dispatch snapshots the previous conversation onto :conv/history. The conversation-level Back button is one line.

• Small async surface. Scheduled events (s/after), publish/subscribe (s/publish! / s/subscribe), and zero-JS multipart uploads route back into normal component handlers.

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Trying it

stube is on Clojars. Add to deps.edn:

{:deps
 {dev.zeko/stube {:mvn/version "0.0.2"}}}

Then in code:

(require '[dev.zeko.stube.core :as s])

The version will move freely while the API settles; nothing in dev.zeko.stube.core is expected to change shape, but anything outside it is internal.

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Running the bundled examples

This project assumes the development environment provided by flake.nix.

nix develop          # enter dev shell
clojure -M:examples  # open http://localhost:8080/ in your browser
clojure -X:test      # run the test suite

The example browser at / indexes every shipped demo. Individual URLs:

path	what it shows
/guess	defflow — guess‑the‑number as straight‑line code
/multicounter	three embedded counters; one click re‑renders one widget
/todo	edit‑in‑place todo list using call-in-slot
/wizard	multi‑step form with a real Back button
/chat	pub/sub across browser tabs
/calendar	structured event payloads
/file-upload	zero‑JS multipart uploads
/clock	scheduled after events
/seaside-todo	a fuller port of the HPI Introduction to Seaside tutorial

Install the Datastar Inspector browser extension to watch the SSE stream live; on the REPL side, (s/inspect cid) prints the live conversation summary and (s/replay :some/root [{:event :submit}]) walks the same path without a browser.

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Status

This is a personal research project, not a product. The implementation is real and the bundled examples work, but the API will move as the underlying experiment evolves. Anything in dev.zeko.stube.core is treated as the stable surface; anything else is internal.

Bug reports, design discussions and Seaside-veteran war stories are all welcome — the more company on this thread, the better.

License

MIT.