我如何在 normalizr.js 中表示多对多关系？

Question

我注意到库得到了很大的改进，但是我找不到如何在库中建立多对多关系。

例如，如果我有用户和 restos。我可能有“喜欢”、“访问”、“想去”等不同的多对多关系。我将如何在 normalizr.js 中对其进行规范化？

Answer 1

您应该关注example of this in the normalizr repo。它需要mergeStrategy 和processStrategy 的组合：

import { schema } from '../../src';

const userProcessStrategy = (value, parent, key) => {
  switch (key) {
    case 'author':
      return { ...value, posts: [parent.id] };
    case 'commenter':
      return { ...value, comments: [parent.id] };
    default:
      return { ...value };
  }
};

const userMergeStrategy = (entityA, entityB) => {
  return {
    ...entityA,
    ...entityB,
    posts: [...(entityA.posts || []), ...(entityB.posts || [])],
    comments: [...(entityA.comments || []), ...(entityB.comments || [])]
  };
};

const user = new schema.Entity(
  'users',
  {},
  {
    mergeStrategy: userMergeStrategy,
    processStrategy: userProcessStrategy
  }
);

const comment = new schema.Entity(
  'comments',
  {
    commenter: user
  },
  {
    processStrategy: (value, parent, key) => {
      return { ...value, post: parent.id };
    }
  }
);

const post = new schema.Entity('posts', {
  author: user,
  comments: [comment]
});

export default [post];