svg-layout-designer-react/src/utils/saveload.ts

import { findContainerById, MakeIterator } from './itertools';
import { IEditorState } from '../Interfaces/IEditorState';

/**
 * Revive the Editor state
 * by setting the containers references to their parent
 * @param editorState Editor state
 */
export function Revive(editorState: IEditorState): void {
  const history = editorState.history;

  // restore last step
  editorState.historyCurrentStep = history.length - 1;

  // restore the parents and the selected container
  for (const state of history) {
    if (state.MainContainer === null || state.MainContainer === undefined) {
      continue;
    }

    const it = MakeIterator(state.MainContainer);
    for (const container of it) {
      const parentId = container.properties.parentId;
      if (parentId === null) {
        container.parent = null;
        continue;
      }
      const parent = findContainerById(state.MainContainer, parentId);
      if (parent === undefined) {
        continue;
      }
      container.parent = parent;
    }

    const selected = findContainerById(state.MainContainer, state.SelectedContainerId);
    if (selected === undefined) {
      state.SelectedContainer = null;
      continue;
    }
    state.SelectedContainer = selected;
  }
}

export const getCircularReplacer = (): (key: any, value: object | null) => object | null | undefined => {
  const seen = new WeakSet();
  return (key: any, value: object | null) => {
    if (key === 'parent') {
      return;
    }

    if (key === 'SelectedContainer') {
      return;
    }

    if (typeof value === 'object' && value !== null) {
      if (seen.has(value)) {
        return;
      }
      seen.add(value);
    }
    return value;
  };
};