regular-redux-undo/src/module/module.js

the plugin of regular-redux to archieve undo and redo

import { forEachValue, isEmpty, error, typeOf} from '../util';

export default class Module {

  constructor(rawModule, path) {
    this._children = Object.create(null);
    this._rawModule = rawModule;
    this.path = path;
    const state = rawModule.state || {};
    this.state = typeOf(state) === 'function' ? state() : state;
  }

  addChild(key, module) {
    this._children[key] = module
  }

  getChild(key) {
    return this._children[key]
  }

  removeChild(key) {
    delete this._children[key]
  }

  hasChild() {
    return !isEmpty(this._children);
  }

  get reducers() {
    return this._rawModule.reducers || {};
  }

  /**
   * traverse the module including its submodule
   * @param {Function} the callback to do something
   */
  forEachModule(fn) {
    fn(this);
    forEachValue(this._children, (module) => {
      module.forEachModule(fn);
    })
  }

  /**
   * check the module state, to see whether it is an object or not when it has submodule
   * @param {String} moduleName the name of module
   */
  checkState(moduleName = "the options of regular-redux's store") {
    if (process.env.NODE_ENV !== 'production') { 
      error(this.hasChild() && typeOf(this.state) !== 'object', `module[${moduleName}] has submodules but It's state is not an object`)
      forEachValue(this._children, (module, key) => {
        module.checkState(key);
      })
    }
  }

  combineState() {
    forEachValue(this._children, (module, key) => {
      this.state[key] = module.combineState();
    });
    return this.state;
  }

}