@blockly/block-plus-minus/src/serialization_helper.js

A group of blocks that replace the built-in mutator UI with a +/- based UI.

/**
 * @license
 * Copyright 2022 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import * as Blockly from 'blockly/core';

/**
 * Returns the extra state of the given block (either as XML or a JSO, depending
 * on the block's definition).
 * @param {!Blockly.BlockSvg} block The block to get the extra state of.
 * @returns {string} A stringified version of the extra state of the given
 *     block.
 */
export function getExtraBlockState(block) {
  // TODO: This is a dupe of the BlockChange.getExtraBlockState code, do we
  //    want to make that public?
  if (block.saveExtraState) {
    const state = block.saveExtraState();
    return state ? JSON.stringify(state) : '';
  } else if (block.mutationToDom) {
    const state = block.mutationToDom();
    return state ? Blockly.Xml.domToText(state) : '';
  }
  return '';
}