如何处理Flux应用程序中的嵌套API响应？

Question

我正在将一个现有的应用程序移植到Flux,我对一个主题感到有些困惑.假设我有几个返回两级或三级嵌套对象的API端点.

例如,GET /articles可以返回架构的JSON响应

articles: article*

article: {
  author: user,
  likers: user*
  primary_collection: collection?
  collections: collection*
}

collection: {
  curator: user
}

如您所见,不同级别的嵌套有各种各样的用户:

• articles[i].author
• articles[i].likers[i]
• articles[i].primaryCollection.curator
• articles[i].collections[i].curator

如果我想在UserStore任何时候获取文章时使用新数据进行更新,我必须编写一个怪异的方法来检查文章API响应中的所有嵌套实体.此外,会有很多重复,因为还有其他API端点具有不同的模式,有时文章嵌入在用户内(例如GET /user/published).

Flux商店是否有更清晰的方法从所有API响应中提取嵌套实体？

Answer 1

Jing Chen(Flux创作者和传播者之一)提出的一种方法是在API响应到达商店之前将其平铺.我写了一个小型库,它就是这样做的:它正常化了

[{
  id: 1,
  title: 'Some Article',
  author: {
    id: 1,
    name: 'Dan'
  }
}, {
  id: 2,
  title: 'Other Article',
  author: {
    id: 1,
    name: 'Dan'
  }
}]

至

{
  result: [1, 2],
  entities: {
    articles: {
      1: {
        id: 1,
        title: 'Some Article',
        author: 1
      },
      2: {
        id: 2,
        title: 'Other Article',
        author: 1
      }
    },
    users: {
      1: {
        id: 1,
        name: 'Dan'
      }
    }
  }
}

(注意没有重复,结构是平的.)

Normalizr让您:

• 将实体嵌套在其他实体,对象和数组中
• 结合实体模式来表达任何类型的API响应
• 自动合并具有相同ID的实体(如果它们不同则带有警告)
• 使用自定义ID属性(例如slug)

要使用它,您需要定义实体和嵌套规则并使用它们来转换JSON:

var normalizr = require('normalizr'),
    normalize = normalizr.normalize,
    Schema = normalizr.Schema,
    arrayOf = normalizr.arrayOf;

// First, define a schema:

var article = new Schema('articles'),
    user = new Schema('users'),
    collection = new Schema('collections');

// Define nesting rules:

article.define({
  author: user,
  collections: arrayOf(collection)
});

collection.define({
  curator: user
});


// Usage:

// Normalize articles
var articlesJSON = getArticleArray(),
    normalized = normalize(articlesJSON, arrayOf(article));

// Normalize users
var usersJSON = getUsersArray(),
    normalized = normalize(usersJSON, arrayOf(user));

// Normalize single article
var articleJSON = getArticle(),
    normalized = normalize(articleJSON, article);

这允许您在将任何XHR响应传递给Flux Dispatcher之前对其进行标准化.商店只需要从相应的字典中更新自己:

// UserStore

UserStore.dispatchToken = AppDispatcher.register(function (payload) {
  var action = payload.action;

  switch (action.type) {
  // you can add any normalized API here since that contains users:
  case ActionTypes.RECEIVE_ARTICLES:
  case ActionTypes.RECEIVE_USERS:

    // Users will always be gathered in action.entities.users
    mergeInto(_users, action.entities.users);
    UserStore.emitChange();
    break;
  }
});


// ArticleStore

AppDispatcher.register(function (payload) {
  var action = payload.action;

  switch (action.type) {
  // you can add any normalized API here since that contains articles:
  case ActionTypes.RECEIVE_ARTICLES:

    // Wait for UserStore to digest users
    AppDispatcher.waitFor([UserStore.dispatchToken]);

    // Articles will always be gathered in action.entities.articles
    mergeInto(_articles, action.entities.articles);
    ArticleStore.emitChange();
    break;
  }
});