從嵌套串列組合物件

我有一個從 XML 生成的通用 json。

{
  "contextInfoDTOList": [
    {
      "key": "context_info",
      "list": [
        {
          "key": "composition",
          "list": [
            {
              "key": "parts",
              "list": [
                {
                  "key": "part",
                  "list": [
                    {
                      "list": [
                        {
                          "key": "materials",
                          "list": [
                            {
                              "key": "material",
                              "list": [
                                {
                                  "key": "material_value",
                                  "value": "100"
                                },
                                {
                                  "key": "material_name",
                                  "value": "polyester"
                                }
                              ]
                            }
                          ]
                        },
                        {
                          "key": "part_name",
                          "value": "LINING"
                        }
                      ]
                    },
                    {
                      "list": [
                        {
                          "key": "materials",
                          "list": [
                            {
                              "key": "material",
                              "list": [
                                {
                                  "key": "material_value",
                                  "value": "100"
                                },
                                {
                                  "key": "material_name",
                                  "value": "cow leather"
                                }
                              ]
                            }
                          ]
                        },
                        {
                          "key": "part_name",
                          "value": "OUTER SHELL"
                        }
                      ]
                    }
                  ]
                }
              ]
            }
          ]
        },
        {
          "key": "explanation"
        }
      ]
    }
  ]
}

我需要將資訊提取為這樣的：

COMPOSITION

Lining

100 % polyester

Outer Shell

100 % cow leather

我嘗試了一種 forEach 方法，加入了鍵（成分、零件、材料......），但它變得很臟，我無法獲得材料清單。

我正在考慮使用 reduce 來獲取物件，但我不知道如何傳遞物件并通過嵌套串列使用遞回。

想要的物件：

export class ContextInfo {
  composition: Composition;
  explanation: string;
}
export class Composition {
  parts: Part[] = [];
}

export class Part {
  partName: string;
  materials: Material[] = [];
}

export class Material {
  name: string;
  value: number;
}

任何幫助，將不勝感激。提前致謝！

uj5u.com熱心網友回復：

現在是你的責任，處理資料......

let contextInfoDTOList = [{ key: "context_info", list: [{ key: "composition", list: [{ key: "parts", list: [{ key: "part", list: [{ list: [{ key: "materials", list: [{ key: "material", list: [{ key: "material_value", value: "100" }, { key: "material_name", value: "polyester" }] }] }, { key: "part_name", value: "LINING" }] }, { list: [{ key: "materials", list: [{ key: "material", list: [{ key: "material_value", value: "100" }, { key: "material_name", value: "cow leather" }] }] }, { key: "part_name", value: "OUTER SHELL" }] }] }] }] }, { key: "explanation" }] }]
function* getAllKeyValue(list = [], path = []) {
    for (let item of list)
        if ("value" in item)
            yield [item, path]
        else
            yield* getAllKeyValue(item.list, path.concat(item.key))
}
for (let [item, _path] of getAllKeyValue(contextInfoDTOList)) {
    console.log(item);
    // Todo: work with the data
}

uj5u.com熱心網友回復：

這是一種非常丑陋的輸入格式。但是通過不斷過濾和查找節點，我們可以以相當合理的方式構建您的輸出：

const byKey = (target) => ({key}) => key == target

const extract = (res) => res .contextInfoDTOList .filter (byKey ('context_info')) .map (info => ({
  explanation: info .list .find (byKey ('explanation')) .value,
  composition: info .list .find (byKey ('composition')) .list .filter (byKey ('parts')) .map (parts => ({
    parts: parts .list .filter (byKey ('part')) .flatMap (p => p.list .map (q => q.list)) .map (part => ({
      partName: part .find (byKey ('part_name')) .value,
      material: part .find (byKey ('materials')) .list .map (material => ({
        name: material .list .find (byKey ('material_name')) .value,
        value: material .list .find (byKey ('material_value')) .value
      }))
    }))
  }))
}))


const res = {contextInfoDTOList: [{key: "context_info", list: [{key: "composition", list: [{key: "parts", list: [{key: "part", list: [{list: [{key: "materials", list: [{key: "material", list: [{key: "material_value", value: "100"}, {key: "material_name", value: "polyester"}]}]}, {key: "part_name", value: "LINING"}]}, {list: [{key: "materials", list: [{key: "material", list: [{key: "material_value", value: "100"}, {key: "material_name", value: "cow leather"}]}]}, {key: "part_name", value: "OUTER SHELL"}]}]}]}]}, {key: "explanation", value: "foobar"}]}]}

console .log (extract (res))

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

（請注意，我必須向"value"您的"explanation"節點添加一個虛擬節點才能正確提取它。如果我們不這樣做，我們會得到一個undefined解釋。）

我們使用助手byKey只是為了減少函式體中的噪音。

標籤：javascript 打字稿 递归

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