使用lodash查找深度嵌套的JSON属性

Question

我有以下结构的JSON API响应

[
  {
    title: "top1",
    sections: [
      {
        section_title: "section1",
        content: [
          {
            content_title: "title1",
            content_id: "id1"
          },
          {
            content_title: "title2",
            content_id: "id2"
          }
        ]
      },
      {
        section_title: "section2",
        content: [
          {
            content_title: "title3",
            content_id: "id3"
          },
          {
            content_title: "title4",
            content_id: "id4"
          }
        ]
      }
    ]
  }, {
    title: "top2",
    sections: [...]
  },
  ...
]

我还有一小部分内容ID arr2 = ['id2','id3'] 。 我需要从API请求中搜索数据，以找到arr2包含的任何content_id。

我有一些工作的lodash代码，但是我的嵌套forEach方法似乎并不是最有效的方法：

_.forEach(response, function(top) {
  _.forEach(top.sections, function(section) {
    _.forEach(section.content, function(content) {
      _.forEach(arr2, function(id) {
        if(id === content.content_id) {
         // Do stuff
        }
      })
    })
  })
})

我如何改善此代码？

Answer 1

经过一番思考，我实际上无法为您提供使用其他lodash函数的更优雅的解决方案。 似乎为每种情况设置拥有的属性都是forEach的。 我唯一可以做的优化就是避免通过简单地使用香草javascript forEach Array函数来使用lodash，并使用find替换最里面的forEach（可能会稍微改善性能）。

response.forEach((topItem) => {
    topItem.sections.forEach((section) => {
        section.content.forEach((content) => {
            if(arr2.find((item) => { return item === content.content_id; })){
                topItem.owned = true; section.owned = true; content.owned = true;
            }
        });
    });
});

我对箭头函数语法也有个人偏好...

Answer 2

您可以创建一个函数，该函数以递归方式遍历已识别的后代属性。

function deepWalk(collection, childKeys, iteratee) {

  // create a partial _.each with an iterator that will
  // recursively traverse properties from the `childKeys` array
  var each = _.partial(_.each, _, function(value, index) {
    // invoke iteratee callback
    iteratee(value, index);
    // only recursively iterate over properties found in childKeys
    _(value).pick(childKeys).each(each);
  });

  // invoke iteration
  each(collection);

}

deepWalk(collection, ['sections', 'content'], function(value) {
  if(_.includes(['id2', 'id3'], value.content_id)) {
    // do whatever you want here..
    console.log(value);
  }
});

 var collection = [ { title: "top1", sections: [ { section_title: "section1", content: [ { content_title: "title1", content_id: "id1" }, { content_title: "title2", content_id: "id2" } ] }, { section_title: "section2", content: [ { content_title: "title3", content_id: "id3" }, { content_title: "title4", content_id: "id4" } ] } ] } ]; function deepWalk(collection, childKeys, iteratee) { // create a partial _.each with an iterator that will // recursively traverse properties from the `childKeys` array var each = _.partial(_.each, _, function(value, index) { // invoke iteratee callback iteratee(value, index); // only recursively iterate over properties found in childKeys _(value).pick(childKeys).each(each); }); // invoke iteration each(collection); } deepWalk(collection, ['sections', 'content'], function(value) { if(_.includes(['id2', 'id3'], value.content_id)) { // do whatever you want here.. console.log(value); } }); 

 .as-console-wrapper { min-height: 100%; top: 0; } 

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