Function appendDomToWorkspace

packages/blockly/core/xml.ts:555–604

(
  xml: Element,
  workspace: WorkspaceSvg,
)

 * @returns An array containing new block IDs.
 */
export function appendDomToWorkspace(
  xml: Element,
  workspace: WorkspaceSvg,
): string[] {
  // First check if we have a WorkspaceSvg, otherwise the blocks have no shape
  // and the position does not matter.
  // Assume it is rendered so we can check.
  if (!(workspace as WorkspaceSvg).getBlocksBoundingBox) {
    return domToWorkspace(xml, workspace);
  }

  const bbox = (workspace as WorkspaceSvg).getBlocksBoundingBox();
  // Load the new blocks into the workspace and get the IDs of the new blocks.
  const newBlockIds = domToWorkspace(xml, workspace);
  if (bbox && bbox.top !== bbox.bottom) {
    // Check if any previous block.
    let offsetY = 0; // Offset to add to y of the new block.
    let offsetX = 0;
    const farY = bbox.bottom; // Bottom position.
    const topX = workspace.RTL ? bbox.right : bbox.left; // X of bounding box.
    // Check position of the new blocks.
    let newLeftX = Infinity; // X of top left corner.
    let newRightX = -Infinity; // X of top right corner.
    let newY = Infinity; // Y of top corner.
    const ySeparation = 10;
    for (let i = 0; i < newBlockIds.length; i++) {
      const blockXY = workspace
        .getBlockById(newBlockIds[i])!
        .getRelativeToSurfaceXY();
      if (blockXY.y < newY) {
        newY = blockXY.y;
      }
      if (blockXY.x < newLeftX) {
        // if we left align also on x
        newLeftX = blockXY.x;
      }
      if (blockXY.x > newRightX) {
        // if we right align also on x
        newRightX = blockXY.x;
      }
    }
    offsetY = farY - newY + ySeparation;
    offsetX = workspace.RTL ? topX - newRightX : topX - newLeftX;
    for (let i = 0; i < newBlockIds.length; i++) {
      const block = workspace.getBlockById(newBlockIds[i]);
      block!.moveBy(offsetX, offsetY, ['create']);
    }
  }
  return newBlockIds;
}

/**
 * Decode an XML block tag and create a block (and possibly sub blocks) on the