MarkoService

interface MarkoService {
  state: Dict;
  send: (event: Dict) => void;
  context: Dict;
  prop: (key: string) => any;
  scope: Dict;
  refs: Dict;
  computed: (key: string) => any;
  event: Dict;
  getStatus: () => string;
  start: () => void;
  stop: () => void;
  propsChanged: () => void;
}

A running (or, for SSR, never-started) Zag machine service — the object
every machineModule.connect(service, normalizeProps) call consumes.
Structurally identical to the service Zag’s own framework adapters produce,
plus three Marko-lifecycle methods.

Zag protocol members

Member Description
state Current state accessor with matches(...values) / hasTag(tag) helpers.
send(event) Sends an event to the machine. Processed on a microtask; a no-op unless the machine is started.
context Bindable context accessor: get / set / initial / hash by key.
prop(key) Reads a resolved machine prop (user props merged over machine defaults).
scope Zag scope (id, ids, getRootNode) used for DOM queries.
refs Mutable non-reactive refs store: get(key) / set(key, value).
computed(key) Evaluates a machine computed value.
event Current event, with current() / previous() accessors.
getStatus() "Not Started" | "Started" | "Stopped".

Marko lifecycle members

Member Description
start() Client-only. Marks the machine started and runs entry actions/effects. Call from <lifecycle onMount>. Also schedules one recompute so the handler-less SSR attributes are replaced with handler-bearing ones.
stop() Stops the machine, running exit actions and effect cleanups. Call from <lifecycle onDestroy>.
propsChanged() Host notification that reactive props changed (controlled usage): invalidates the props cache, syncs bindable prev trackers, re-runs machine.watch tracks, and notifies the renderer.

Remarks

A MarkoService instance is not serializable and must never cross the
server/client boundary:

  • Server — keep it out of reactive state; build a throwaway via
    ssrService inside the render expression.
  • Client — store the real instance in a <let/svc=null> (the null
    serializes; the instance is created fresh in onMount).

The <service> tag implements this contract for you.

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