scxmljs by tinyactors

Changelog

All notable changes to @tinyactors/scxmljs are listed here. The format follows Keep a Changelog.

Versioning#

The package follows Semantic Versioning, with the usual rule for 0.x: until 1.0, a minor version (0.1 → 0.2) may contain breaking changes, and a patch version (0.1.0 → 0.1.1) contains only fixes and additions. Every breaking change is listed under Changed or Removed with what to do instead.

The public API is everything the entry points export (@tinyactors/scxmljs, /trusted, /view, /explorer), the custom elements' attributes, properties, events, slots and ::part() names, the --scxml-* custom properties, and themes/tinyactors.css. Anything marked @internal, the files under dist/ other than the entry points, class names inside the shadow DOM and the private --x-* properties are not public API and can change in any release.

Unreleased#

Added#

  • <scxml-view>: the event-data attribute gives label clicks event data (a JSON object from event names to data), and scxml-send listeners can set detail.data.
  • <scxml-view>: when a clicked event changes nothing, or raises an error (for example a condition that throws, which counts as false), a send-status bar says so, and the live region announces it. Before, the click looked like it did nothing.
  • <scxml-explorer>: list rows answer "what is this state, what happens in it, how do I get out": entry actions and invokes, transitions as "event → target" with a condition mark, send buttons while the state is active, a "last visited" mark, and a click that opens the row in place. New parts: list-row modifiers active visited open, visited, row-actions, row-exits, row-event (fired), row-detail, open-detail; card and lane-row get visited, edge-label gets fired. New strings: onEntry, eventless, guard, justTaken, lastVisited, openDetail, lastStep.

Changed#

  • <scxml-explorer> is quieter: one header bar (the playback controls moved into it), no status badges or redundant counts, sentence-case labels, hairlines instead of boxes, and colour only for meaning (running colour: active; waiting colour: what the last step did). The System level hides the tree and shows the service inspector.
  • <scxml-explorer> parts: speeds is now a <select> (it was a group of buttons); last-step moved from the playback bar to under the title; send is now the event's name itself (there's no separate Send button); event-data is a <details> disclosure. The playback bar's queue readout is the clock part's tooltip. The English focusSummary no longer lists all descendants and traffic gives a message total.

0.1.0 - 2026-09-28#

The first release.

Added#

  • An SCXML 1.0 interpreter with the ECMAScript data model. All 160 automatic mandatory W3C conformance tests pass in both data models; see docs/conformance.md and docs/deviations.md.
  • Two entry points with the same API: @tinyactors/scxmljs runs chart code in a QuickJS sandbox (WebAssembly), with a per-evaluation timeout (scriptTimeoutMs) and a per-session memory limit (memoryLimitBytes); @tinyactors/scxmljs/trusted runs it in the host's engine.
  • Load-time validation (SCXMLValidationError with every problem) and authoring warnings (model.warnings).
  • Clocks: realClock, VirtualClock for tests, PlaybackClock for pause, step and speed.
  • Custom Event I/O Processors and invokers; SCXML child sessions with a loader for src.
  • Typed session events, settled(), waitFor(), steps() and snapshot().
  • Page integration: connect(), bind() with data-scxml-* attributes, and the opt-in reflect and elementEvents options.
  • <scxml-view> (@tinyactors/scxmljs/view): a whole chart, drawn and running, with no JavaScript of your own.
  • <scxml-explorer> (@tinyactors/scxmljs/explorer): explore running systems level by level, and its view-model.
  • A shared theming contract (--scxml-* tokens, ::part()), a neutral light/dark default theme, and themes/tinyactors.css.
  • Works under a strict Content-Security-Policy (no 'unsafe-inline' styles) and with Trusted Types (sandboxed entry point); see docs/csp.md.
  • <scxml-view> scales a too-wide diagram down on its own, no further than --scxml-min-scale (default 0.65); fit scales all the way. A terminated session keeps its final states marked (reached), and an element with nothing to show yet shows a hint instead of an error (a host may set session later).
  • Tested in CI in Chromium, Firefox and WebKit (functional, screenshots, axe-core with no violations), in Node, Bun and Deno from the packed tarball, and with React 19, Vue 3, Svelte 5 and Angular 22 apps; see docs/bundling.md.