拉姆达：折叠一个物体

Question

我正在构建PWA，并与Ramda进行逻辑构建。我正在尝试构建给定Google Places Detail响应返回自定义地址对象的函数。

让我通过向我展示测试来在代码中描述它：

assert({
  given: 'a google places api response from Google Places',
  should: 'extract the address',
  actual: getAddressValues({
    address_components: [
      {
        long_name: '5',
        short_name: '5',
        types: ['floor'],
      },
      {
        long_name: '48',
        short_name: '48',
        types: ['street_number'],
      },
      {
        long_name: 'Pirrama Road',
        short_name: 'Pirrama Rd',
        types: ['route'],
      },
      {
        long_name: 'Pyrmont',
        short_name: 'Pyrmont',
        types: ['locality', 'political'],
      },
      {
        long_name: 'Council of the City of Sydney',
        short_name: 'Sydney',
        types: ['administrative_area_level_2', 'political'],
      },
      {
        long_name: 'New South Wales',
        short_name: 'NSW',
        types: ['administrative_area_level_1', 'political'],
      },
      {
        long_name: 'Australia',
        short_name: 'AU',
        types: ['country', 'political'],
      },
      {
        long_name: '2009',
        short_name: '2009',
        types: ['postal_code'],
      },
    ],
    geometry: {
      location: {
        lat: -33.866651,
        lng: 151.195827,
      },
      viewport: {
        northeast: {
          lat: -33.8653881697085,
          lng: 151.1969739802915,
        },
        southwest: {
          lat: -33.86808613029149,
          lng: 151.1942760197085,
        },
      },
    },
  }),
  expected: {
    latitude: -33.866651,
    longitude: 151.195827,
    city: 'Pyrmont',
    zipCode: '2009',
    streetName: 'Pirrama Road',
    streetNumber: '48',
  },
});

如您所见，我想要的地址对象更加“扁平”（缺少更好的术语）。我正在努力编写此转换函数。我尝试使用Ramda's做到这一点evolve，但这可以保留关键。我将需要使用Evolution来变换对象，然后reduce使用对象来扩展键。

// Pseudo
({ address_components }) => ({ ...address_components })

我成功地evolve使用renameKeys了Ramda附件提取了相关信息，并使用Ramda附件将其重命名了，但是我不知道之后如何使该对象变平。你是怎样做的？还是有一种更简单的方法来实现所需的转换？

编辑：

我找到了实现转换的方法，但是转换很冗长。我觉得有一种更简单的方法来提取地址数据。无论如何，这是我当前的解决方案：

export const getAddressValues = pipe(
  evolve({
    address_components: pipe(
      reduce(
        (acc, val) => ({
          ...acc,
          ...{
            [head(prop('types', val))]: prop('long_name', val),
          },
        }),
        {}
      ),
      pipe(
        pickAll([
          'route',
          'locality',
          'street_number',
          'country',
          'postal_code',
        ]),
        renameKeys({
          route: 'streetName',
          locality: 'city',
          street_number: 'streetNumber',
          postal_code: 'zipCode',
        }),
        map(ifElse(isNil, always(null), identity))
      )
    ),
    geometry: ({ location: { lat, lon } }) => ({
      latitude: lat,
      longitude: lon,
    }),
  }),
  ({ address_components, geometry }) => ({ ...address_components, ...geometry })
);

编辑：基于@codeepic的答案，这是我最终使用的普通JavaScript解决方案（尽管@ user3297291的效果很好，我喜欢它）：

const getLongNameByType = (arr, type) => 
  arr.find(o => o.types.includes(type)).long_name;

const getAddressValues = ({ address_components: comp, geometry: { location: { lat, lng } } }) => ({
  latitude: lat,
  longitude: lng,
  city: getLongNameByType(comp, 'locality'),
  zipCode: getLongNameByType(comp, 'postal_code'),
  streetName: getLongNameByType(comp, 'route'),
  streetNumber: getLongNameByType(comp, 'street_number'),
  country: getLongNameByType(comp, 'country'),
});

Answer 1

也许没有多大改进，但我有一些建议：

• 您可以使用indexBy而不是（有点难以阅读）内联归约函数。
• 通过拆分地址和位置逻辑，并创建一个组合助手来将两者结合起来，可以更轻松地读取发生的情况（使用juxt和mergeAll）
• 您可以使用+applySpec代替pickAllrenameKeys

const { pipe, indexBy, prop, head, compose, path, map, applySpec, juxt, mergeAll } = R;

const reformatAddress = pipe(
  prop("address_components"),
  indexBy(
    compose(head, prop("types"))
  ),
  applySpec({
    streetName: prop("route"),
    city: prop("locality"),
    streetNumber: prop("street_number"),
    zipCode: prop("postal_code"),
  }),
  map(prop("long_name"))
);

const reformatLocation = pipe(
  path(["geometry", "location"]),
  applySpec({
    latitude: prop("lat"),
    longitude: prop("lng")
  })
);

// Could also be: converge(mergeRight, [ f1, f2 ])
const formatInput = pipe(
  juxt([ reformatAddress, reformatLocation]),
  mergeAll
);

console.log(formatInput(getInput()));


function getInput() { return {address_components:[{long_name:"5",short_name:"5",types:["floor"]},{long_name:"48",short_name:"48",types:["street_number"]},{long_name:"Pirrama Road",short_name:"Pirrama Rd",types:["route"]},{long_name:"Pyrmont",short_name:"Pyrmont",types:["locality","political"]},{long_name:"Council of the City of Sydney",short_name:"Sydney",types:["administrative_area_level_2","political"]},{long_name:"New South Wales",short_name:"NSW",types:["administrative_area_level_1","political"]},{long_name:"Australia",short_name:"AU",types:["country","political"]},{long_name:"2009",short_name:"2009",types:["postal_code"]}],geometry:{location:{lat:-33.866651,lng:151.195827},viewport:{northeast:{lat:-33.8653881697085,lng:151.1969739802915},southwest:{lat:-33.86808613029149,lng:151.1942760197085}}}}; }

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