Function parseSubComposition

packages/cli/src/commands/compositions.ts:108–168

(
  html: string,
  fallbackId: string,
  fallbackWidth: number,
  fallbackHeight: number,
)

}

export function parseSubComposition(
  html: string,
  fallbackId: string,
  fallbackWidth: number,
  fallbackHeight: number,
): CompositionInfo {
  const parser = new DOMParser();
  const doc = parser.parseFromString(html, "text/html");
  const template = doc.querySelector("template");
  const searchDocument = template?.content ?? doc;

  // Sub-compositions may use <template> wrappers or direct divs
  const compDiv = searchDocument.querySelector("[data-composition-id]");

  const id = compDiv?.getAttribute("data-composition-id") ?? fallbackId;
  const width = parseInt(compDiv?.getAttribute("data-width") ?? String(fallbackWidth), 10);
  const height = parseInt(compDiv?.getAttribute("data-height") ?? String(fallbackHeight), 10);

  // Count timed elements inside the sub-composition
  const searchRoot = compDiv ?? searchDocument;
  const timedChildren = searchRoot.querySelectorAll("[data-start], .clip, .caption-group");
  let elementCount = timedChildren.length;
  if (elementCount === 0 && compDiv) {
    elementCount = countRenderableDescendants(compDiv);
  }

  // Parse duration from the composition's own data-duration attribute
  let duration = 0;
  const durationAttr = compDiv?.getAttribute("data-duration");
  if (durationAttr && !durationAttr.startsWith("__")) {
    duration = parseFloat(durationAttr) || 0;
  }

  // Also check timed children for max end time
  if (compDiv) {
    const timedEls = compDiv.querySelectorAll("[data-start]");
    timedEls.forEach((el) => {
      elementCount = Math.max(elementCount, timedEls.length);
      const start = parseFloat(el.getAttribute("data-start") ?? "0");
      const endAttr = el.getAttribute("data-end");
      const durAttr = el.getAttribute("data-duration");

      let end: number;
      if (endAttr) {
        end = parseFloat(endAttr);
      } else if (durAttr) {
        end = start + parseFloat(durAttr);
      } else {
        end = start + 5;
      }
      if (end > duration) {
        duration = end;
      }
    });
  }
  if (duration <= 0) {
    duration = estimateDurationFromScripts(searchRoot);
  }