Function parse

src/third_party/html-parser/html-parser.ts:105–234

(data: string, rootElement: Element)

 * @return {Element}      root element
 */
export function parse(data: string, rootElement: Element) {
  const ownerDocument = rootElement.ownerDocument;
  const root = ownerDocument.createElementNS(rootElement.namespaceURI, rootElement.localName);

  let currentParent = root as Node;
  let currentNamespace = root.namespaceURI;
  const stack = [root as Node];
  let lastTextPos = 0;
  let match: RegExpExecArray | null;
  data = '<q>' + data + '</q>';
  const tagsClosed = [] as string[];

  if (currentNamespace !== SVG_NAMESPACE && currentNamespace !== HTML_NAMESPACE) {
    throw new Error('Namespace not supported: ' + currentNamespace);
  }

  while ((match = kMarkupPattern.exec(data))) {
    const commentContents = match[1]; // <!--contents-->
    const beginningSlash = match[2]; // ... </ ...
    const tagName = match[3];
    const matchAttributes = match[4];
    const endSlash = match[5]; // ... /> ...

    if (lastTextPos < match.index) {
      // if has content
      const text = data.slice(lastTextPos, match.index);
      currentParent.appendChild(ownerDocument.createTextNode(decodeEntities(text)));
    }
    lastTextPos = kMarkupPattern.lastIndex;
    if (commentContents !== undefined) {
      // this is a comment
      currentParent.appendChild(ownerDocument.createComment(commentContents));
      continue;
    }

    const normalizedTagName = toUpper(tagName);

    if (normalizedTagName === 'SVG') {
      currentNamespace = beginningSlash ? HTML_NAMESPACE : SVG_NAMESPACE;
    }

    if (!beginningSlash) {
      // not </ tags
      if (!endSlash && kElementsClosedByOpening[currentParent.tagName]) {
        if (kElementsClosedByOpening[currentParent.tagName][normalizedTagName]) {
          stack.pop();
          currentParent = arr_back(stack);
        }
      }

      const childToAppend = ownerDocument.createElementNS(currentNamespace, currentNamespace === HTML_NAMESPACE ? toLower(tagName) : tagName);

      for (let attMatch; (attMatch = kAttributePattern.exec(matchAttributes)); ) {
        const attrName = attMatch[2];
        const attrValue = attMatch[4] || attMatch[5] || attMatch[6];
        childToAppend.setAttribute(attrName, attrValue);
      }