从数据中删除叶节点

Question

我正在做一个圆形包装，图形中的节点太多，所以我试图通过删除叶节点来减少节点的数量。我从 api 获得的数据是一个 json 对象，如下所示：{    Children: [],     Label: "some str",     Value: some int,     Properties:[]}我正在尝试创建一个循环遍历数据的函数，如果对象没有子对象，则将其删除。这是我正在做的function removeLeaves(data){let keys = Object.entries(data);for(let [name,obj] of keys){    if(name == "Children"){        if((<Array<any>>obj).length > 0){            for(let child of (<Array<any>>obj)){                removeLeaves(child);            }        }        else{            data = {}; //delete object        }    }  }}但由于数据不是引用类型，因此不会保存更改。谁能帮我这个？我正在尝试做类似于 c# removeLeaves(ref data) 的事情或者有什么方法可以去除包装方法中的叶子var pack = data => d3.pack()    .size([width, height])    .padding(5)    (d3.hierarchy(data, d => d.Children)     //here some kind of filtering    .sum(d => {                    return d.Value;    })    .sort((a, b) => b.value - a.value));

Answer 1

我会选择一种递归/以编程方式构建所需数据结构的方法，而不是通过删除不需要的属性来改变现有的输入数据......

// {Children: [], Label: "some str", Value: some int, Properties:[] }

const data = {

  Label: "root_with_children",

  Value: 1,

  Properties: ["foo", "bar"],

  Children: [{

    Label: "level_1_without_children",

    Value: 2,

    Properties: ["foo", "bar"],

    Children: []

  }, {

    Label: "level_1_with_children",

    Value: 3,

    Properties: ["foo", "bar"],

    Children: [{

      Label: "level_2_without_children",

      Value: 4,

      Properties: ["foo", "bar"],

      Children: []

    }, {

      Label: "level_2_with_children",

      Value: 5,

      Properties: ["foo", "bar"],

      Children: [{

        Label: "level_3_without_children",

        Value: 6,

        Properties: ["foo", "bar"],

        Children: []

      }]

    }]

  }]

};

function isNonEmtyArray(type) {

  return (Array.isArray(type) && (type.length >= 1));

}

function collectItemsWithChildrenOnly(list, item) {

  const { Children } = item;

  if (isNonEmtyArray(Children)) {

    const copy = Object.assign({}, item, { Children: [] });

    list.push(copy);

    Children.reduce(collectItemsWithChildrenOnly, copy.Children);

  }

  return list;

}

let test;

test = [data].reduce(collectItemsWithChildrenOnly, []);

console.log('1st run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);

console.log('2nd run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);

console.log('3rd run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);

console.log('4th run :: test : ', test);

test = test.reduce(collectItemsWithChildrenOnly, []);

console.log('countercheck :: test : ', test);

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

Answer 2

假设您获得的对象数组的Children属性是对象数组或空 arr 指示它是叶子，您可以使用以下函数的组合删除叶子节点

const removeEmptyChildren = obj => obj.Children.length

?

    {...obj,Children:leafRemover(obj.Children)}

:

    undefined

const leafRemover = arr => arr.filter( e => removeEmptyChildren(e) !== undefined)

console.log(leafRemover(data)) // where data is array of objects from the server