使用lodash根据类型对多个对象进行分组

时间:2019-05-21 12:11:48

标签: javascript arrays typescript lodash

我想将unordered-list-itemordered-list-item分组。

下面是原始结构:

{
  data: {
    areas: [{
      sections: [{
        rjf: [
          {
            type: "unordered-list-item",
            text: "Item 1",
          },
          {
            type: "unordered-list-item",
            text: "Item 2",
          },
          {
            type: "paragraph",
            text: "This is text",
          }]
      }]
    }]
  }
}

现在,我要将所有列表项分组到一个新对象中。

所以预期的结构是:

{
  data: {
    areas: [{
      sections: [{
        rjf: [
          {
            type: "list",
            items: [{
              type: "unordered-list-item",
              text: "Item 1",
            },
            {
              type: "unordered-list-item",
              text: "Item 2",
            }]
          },
          {
            type: "paragraph",
            text: "This is text",
          }]
      }]
    }]
  }
}

所以我想将所有unordered-list-item and ordered-list-item移到items数组,并且像type这样的后续对象paragraph不应受到影响。

我用TypeScript创建了一个解决方案,但是代码太长了:

const areas = data.areas;
      const listItemTypes = ['unordered-list-item', 'ordered-list-item'];
      return areas.map(area => {
        return area.sections.map(section => {
          let lastHeadingIndex = -1;
          return section.rjf.reduce((acc, current, index) => {
            if (!current.type || !listItemTypes.includes(current.type)) {
              lastHeadingIndex = acc.length;
              return [...acc, current];
            }
            let listObject = acc.find((el, i) => i > lastHeadingIndex && i < index && el.type === 'list');
            if (!listObject) {
              listObject = {
                type: 'list',
                items: [current]
              };
              return [...acc, listObject];
            }
            listObject.items = [...listObject.items, current];
            return acc;
          }, []);
        });
      });

如何使用lodash实现相同的功能?

****更新****

我尝试过lodash,但似乎没有用。

var content = {
  data: {
    areas: [{
      sections: [{
        rjf: [{
            type: "unordered-list-item",
            text: "Item 1",
          },
          {
            type: "unordered-list-item",
            text: "Item 2",
          },
          {
            type: "paragraph",
            text: "This is text",
          }
        ]
      }]
    }]
  }
};

var result = content.data.areas.map((area => {
    return area.sections.map(section => {
       section.rfj = _.groupBy(section.rfj, 'type');
    });
}));

document.body.innerHTML = '<pre>' + JSON.stringify(result, null, '  ') + '</pre>';
<script src="https://cdn.jsdelivr.net/lodash/4.17.2/lodash.min.js"></script>

3 个答案:

答案 0 :(得分:0)

1,000.00 USD

如果您需要更具体的结构,则可能需要对结果进行一些微调,但这应该可以完成大部分工作

答案 1 :(得分:0)

您可以将代码简化为以下形式。

  • mapareas上使用嵌套的sections
  • 您正在从两个map中删除阵列。而是返回具有sectionsrjf属性的对象(假设两个结构都是只有一个属性的对象)
  • 遍历rjf时,创建2个数组:itemsothers
  • 根据types数组includes是否是当前对象的type,将每个对象分为这2个数组。
  • 使用一个list对象({ type: "list", items })和others数组中的其余对象创建一个数组

const types = ['unordered-list-item', 'ordered-list-item'],
      input = {data:{areas:[{sections:[{rjf:[{type:"unordered-list-item",text:"Item 1",},{type:"unordered-list-item",text:"Item 2",},{type:"paragraph",text:"This is text",}]}]}]}}

const areas = input.data.areas.map(a => {
  return {
    sections: a.sections.map(s => {
      const items = [], others = [];
      
      s.rjf.forEach(o =>
        types.includes(o.type) ? items.push(o) : others.push(o)
      )

      return { rjf: [{ type: "list", items }, ...others] }
    })
  }
})

console.log({ data: { areas } })
.as-console-wrapper { max-height: 100% !important; top: 0; }

答案 2 :(得分:0)

您可以使用另一种方法,即复制每个对象leven并映射所有数组,并使用分组函数将最后一级分组。

此方法使用amit函数,该函数获取每个级别和起始对象的所有功能。

最后,它将返回具有给定结构和分组项目的新对象。

function copy(source, fn) {
    return Object.assign({}, ...Object
        .entries(source)
        .map(([k, v]) => ({ [k]: fn(v) }))
    );
}

function map(array, fn) {
    return array.map(fn);
}

function group(array) {
    var items;
    return array.reduce((r, o) => {
        if (listItemTypes.includes(o.type)) {
            if (!items) {
                items = [];
                r.push({ type: 'list', items });
            }
            items.push(o);
        } else {
            items = undefined;
            r.push(o);
        }
        return r;
    }, []);
}

function iter([fn, ...fns], object) {
    return fn ? fn(object, iter.bind(null, fns)) : object;
}    

var object = { data: { areas: [{ sections: [{ rjf: [{ type: "unordered-list-item", text: "Item 1" }, { type: "unordered-list-item", text: "Item 2" }, { type: "paragraph", text: "This is text" }] }] }] } },
    listItemTypes = ['unordered-list-item', 'ordered-list-item'],
    result = iter([copy, copy, map, copy, map, copy, group], object);

console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }