Function domToBlockHeadless

packages/blockly/core/xml.ts:981–1088

* Decode an XML block tag and create a block (and possibly sub blocks) on the * workspace. * * @param xmlBlock XML block element. * @param workspace The workspace. * @param parentConnection The parent connection to connect this block to * after instantiating. * @param connectedToParentNex

(
  xmlBlock: Element,
  workspace: Workspace,
  parentConnection?: Connection,
  connectedToParentNext?: boolean,
)

 * @returns The root block created.
 */
function domToBlockHeadless(
  xmlBlock: Element,
  workspace: Workspace,
  parentConnection?: Connection,
  connectedToParentNext?: boolean,
): Block {
  let block = null;
  const prototypeName = xmlBlock.getAttribute('type');
  if (!prototypeName) {
    throw TypeError('Block type unspecified: ' + xmlBlock.outerHTML);
  }
  const id = xmlBlock.getAttribute('id') ?? undefined;
  block = workspace.newBlock(prototypeName, id);

  // Preprocess childNodes so tags can be processed in a consistent order.
  const xmlChildNameMap = mapSupportedXmlTags(xmlBlock);

  const shouldCallInitSvg = applyMutationTagNodes(
    xmlChildNameMap.mutation,
    block,
  );
  applyCommentTagNodes(xmlChildNameMap.comment, block);
  applyDataTagNodes(xmlChildNameMap.data, block);

  // Connect parent after processing mutation and before setting fields.
  if (parentConnection) {
    if (connectedToParentNext) {
      if (block.previousConnection) {
        parentConnection.connect(block.previousConnection);
      } else {
        throw TypeError('Next block does not have previous statement.');
      }
    } else {
      if (block.outputConnection) {
        parentConnection.connect(block.outputConnection);
      } else if (block.previousConnection) {
        parentConnection.connect(block.previousConnection);
      } else {
        throw TypeError(
          'Child block does not have output or previous statement.',
        );
      }
    }
  }

  applyFieldTagNodes(xmlChildNameMap.field, block);
  applyInputTagNodes(xmlChildNameMap.input, workspace, block, prototypeName);
  applyNextTagNodes(xmlChildNameMap.next, workspace, block);

  if (shouldCallInitSvg) {
    // This shouldn't even be called here
    // (ref: https://github.com/google/blockly/pull/4296#issuecomment-884226021
    // But the XML serializer/deserializer is iceboxed so I'm not going to fix
    // it.
    (block as BlockSvg).initSvg();
  }

  const inline = xmlBlock.getAttribute('inline');