dev.zeko.stube.keyed — dev.zeko/stube 0.2.1

Keyed-children primitive.

A parent can declare an ordered set of child component instances identified by stable user-facing keys instead of fixed slot names. When the set changes, the kernel emits per-child element fragments (:append / :remove / :outer against the container) rather than re-rendering the whole parent.

Surface

• Effect (s/set-keyed-children slot pairs) where pairs is [[stable-key embed-spec] ...] in display order. Triggers the diff fold in reconcile!.
• Render helper (s/keyed-children self slot) returns hiccup for the container <div id=PARENTIID--SLOTNAME> with each child's current HTML inlined in order.

State shape on the parent instance:

:instance/keyed-slots
{:slot/cols {:order    [:c1 :c2]
             :children {:c1 {:iid "ix-000005"
                             :embed {:embed/type :demo/counter
                                     :embed/args {:start 0}}}
                        :c2 {:iid "ix-000006"
                             :embed {…}}}}}

Diff rules

• Key in new but not old → mint, :start, emit :append at the right position (:append/:prepend/:after).
• Key in old but not new → :stop, remove, emit :remove targeting the child iid.
• Same key, different embed args → re-:init the child in place (iid preserved, descendants rebuilt), emit :outer at the child iid.
• Same key, same embed args → no fragment.
• Different order, same key-set → emit one :outer against the whole container (cheaper than a parent re-render; still distinguishable from individual diffs in replay traces).

Before the parent has been rendered the first time, reconcile! performs all the bookkeeping silently and emits no fragments — the parent's normal render-frame will pick up the populated state and emit one container.

child-iid clj

(child-iid self slot key)

Look up the iid of the child mounted under slot/key on self.

container-id clj

(container-id parent-id slot)

DOM id of the keyed-children container element under parent-id/slot.

reconcile! clj

(reconcile! conv parent-id slot pairs run-effects-fn)

Apply the :set-keyed-children effect: update parent-id's :instance/keyed-slots for slot to match pairs, mint/remove/ re-init children, and emit per-change element fragments when the parent is already rendered. Returns [conv' fragments].

render-children-hiccup clj

(render-children-hiccup self slot)

Inline the child instances currently registered for slot on self. Mirrors render/render-slot: looks each child up in render/*conv*, invokes its :render, returns the hiccup so Chassis serialises it in one pass with the parent.