Function openComposition

packages/sdk/src/session.ts:631–669

(
  html: string,
  opts?: OpenCompositionOptions,
)

 */
// fallow-ignore-next-line complexity
export async function openComposition(
  html: string,
  opts?: OpenCompositionOptions,
): Promise<Composition> {
  // Single parse: parseMutable stamps hf-ids + builds the live linkedom DOM;
  // the query API derives element snapshots from it lazily.
  const parsed = parseMutable(html);

  // T3 embedded: replay the stored override-set onto the base in one pass,
  // so the session exposes the user's exact edited state — not the template.
  if (opts?.overrides) applyOverrideSet(parsed, opts.overrides);

  const session = new CompositionImpl(parsed, opts ?? {});

  const isEmbedded = opts?.overrides !== undefined;

  if (!isEmbedded) {
    // history:false opts out of the SDK undo stack ONLY. Persist (auto-save) is
    // independent — gating it on the history flag too would silently drop every
    // disk write for a caller that just wanted to disable undo (data loss).
    if (opts?.history !== false) {
      const history = createHistory(session, {
        coalesceMs: opts?.coalesceMs ?? 300,
        trackedOrigins: opts?.trackedOrigins,
      });
      session.attachHistory(history);
    }

    if (opts?.persist) {
      const pq = createPersistQueue(session, opts.persist, {
        path: opts.persistPath,
        onError: (e) => session._fireError(e),
      });
      session.attachPersistQueue(pq);
    }
  }

  return session;
}