我有一个复杂的json文件,我必须处理javascript使其分层,以便稍后构建树。 json的每个条目都有: Id:唯一的Id, parentId:父节点的id(如果节点是树的根,则为0) Level:树的深度级别

json数据已经“有序”。我的意思是,一个条目在它上面有一个父节点或兄弟节点,在它下面有一个子节点或兄弟节点。

输入:

{
    "People": [
        {
            "id": "12",
            "parentId": "0",
            "text": "Man",
            "level": "1",
            "children": null
        },
        {
            "id": "6",
            "parentId": "12",
            "text": "Boy",
            "level": "2",
            "children": null
        },
                {
            "id": "7",
            "parentId": "12",
            "text": "Other",
            "level": "2",
            "children": null
        },
        {
            "id": "9",
            "parentId": "0",
            "text": "Woman",
            "level": "1",
            "children": null
        },
        {
            "id": "11",
            "parentId": "9",
            "text": "Girl",
            "level": "2",
            "children": null
        }
    ],
    "Animals": [
        {
            "id": "5",
            "parentId": "0",
            "text": "Dog",
            "level": "1",
            "children": null
        },
        {
            "id": "8",
            "parentId": "5",
            "text": "Puppy",
            "level": "2",
            "children": null
        },
        {
            "id": "10",
            "parentId": "13",
            "text": "Cat",
            "level": "1",
            "children": null
        },
        {
            "id": "14",
            "parentId": "13",
            "text": "Kitten",
            "level": "2",
            "children": null
        },
    ]
}

预期产量:

{
    "People": [
        {
            "id": "12",
            "parentId": "0",
            "text": "Man",
            "level": "1",
            "children": [
                {
                    "id": "6",
                    "parentId": "12",
                    "text": "Boy",
                    "level": "2",
                    "children": null
                },
                {
                    "id": "7",
                    "parentId": "12",
                    "text": "Other",
                    "level": "2",
                    "children": null
                }   
            ]
        },
        {
            "id": "9",
            "parentId": "0",
            "text": "Woman",
            "level": "1",
            "children":
            {

                "id": "11",
                "parentId": "9",
                "text": "Girl",
                "level": "2",
                "children": null
            }
        }

    ],    

    "Animals": [
        {
            "id": "5",
            "parentId": "0",
            "text": "Dog",
            "level": "1",
            "children": 
                {
                    "id": "8",
                    "parentId": "5",
                    "text": "Puppy",
                    "level": "2",
                    "children": null
                }
        },
        {
            "id": "10",
            "parentId": "13",
            "text": "Cat",
            "level": "1",
            "children": 
            {
                "id": "14",
                "parentId": "13",
                "text": "Kitten",
                "level": "2",
                "children": null
            }
        }

    ]
}

当前回答

这是上面的一个修改版本,适用于多个根项,我使用guid为我的id和parentid,所以在创建它们的UI中,我硬编码根项为0000000-00000-00000-TREE-ROOT-ITEM

var树= unflatten(记录," tree - root - item ");

function unflatten(records, rootCategoryId, parent, tree){
    if(!_.isArray(tree)){
        tree = [];
        _.each(records, function(rec){
            if(rec.parentId.indexOf(rootCategoryId)>=0){        // change this line to compare a root id
            //if(rec.parentId == 0 || rec.parentId == null){    // example for 0 or null
                var tmp = angular.copy(rec);
                tmp.children = _.filter(records, function(r){
                    return r.parentId == tmp.id;
                });
                tree.push(tmp);
                //console.log(tree);
                _.each(tmp.children, function(child){
                    return unflatten(records, rootCategoryId, child, tree);
                });
            }
        });
    }
    else{
        if(parent){
            parent.children = _.filter(records, function(r){
                return r.parentId == parent.id;
            });
            _.each(parent.children, function(child){
                return unflatten(records, rootCategoryId, child, tree);
            });
        }
    }
    return tree;
}

其他回答

你可以使用这个来自Github或NPM的“treeify”包。

安装:

$ NPM install——save-dev treeify-js

一个更简单的从列表到树的函数

NPM安装列表到树精简版

listToTree(列表)

来源:

function listToTree(data, options) {
    options = options || {};
    var ID_KEY = options.idKey || 'id';
    var PARENT_KEY = options.parentKey || 'parent';
    var CHILDREN_KEY = options.childrenKey || 'children';

    var tree = [],
        childrenOf = {};
    var item, id, parentId;

    for (var i = 0, length = data.length; i < length; i++) {
        item = data[i];
        id = item[ID_KEY];
        parentId = item[PARENT_KEY] || 0;
        // every item may have children
        childrenOf[id] = childrenOf[id] || [];
        // init its children
        item[CHILDREN_KEY] = childrenOf[id];
        if (parentId != 0) {
            // init its parent's children object
            childrenOf[parentId] = childrenOf[parentId] || [];
            // push it into its parent's children object
            childrenOf[parentId].push(item);
        } else {
            tree.push(item);
        }
    };

    return tree;
}

斯菲德尔

这是上面的一个修改版本,适用于多个根项,我使用guid为我的id和parentid,所以在创建它们的UI中,我硬编码根项为0000000-00000-00000-TREE-ROOT-ITEM

var树= unflatten(记录," tree - root - item ");

function unflatten(records, rootCategoryId, parent, tree){
    if(!_.isArray(tree)){
        tree = [];
        _.each(records, function(rec){
            if(rec.parentId.indexOf(rootCategoryId)>=0){        // change this line to compare a root id
            //if(rec.parentId == 0 || rec.parentId == null){    // example for 0 or null
                var tmp = angular.copy(rec);
                tmp.children = _.filter(records, function(r){
                    return r.parentId == tmp.id;
                });
                tree.push(tmp);
                //console.log(tree);
                _.each(tmp.children, function(child){
                    return unflatten(records, rootCategoryId, child, tree);
                });
            }
        });
    }
    else{
        if(parent){
            parent.children = _.filter(records, function(r){
                return r.parentId == parent.id;
            });
            _.each(parent.children, function(child){
                return unflatten(records, rootCategoryId, child, tree);
            });
        }
    }
    return tree;
}

我喜欢@WilliamLeung的纯JavaScript解决方案,但有时你需要在现有数组中进行更改,以保持对对象的引用。

function listToTree(data, options) {
  options = options || {};
  var ID_KEY = options.idKey || 'id';
  var PARENT_KEY = options.parentKey || 'parent';
  var CHILDREN_KEY = options.childrenKey || 'children';

  var item, id, parentId;
  var map = {};
    for(var i = 0; i < data.length; i++ ) { // make cache
    if(data[i][ID_KEY]){
      map[data[i][ID_KEY]] = data[i];
      data[i][CHILDREN_KEY] = [];
    }
  }
  for (var i = 0; i < data.length; i++) {
    if(data[i][PARENT_KEY]) { // is a child
      if(map[data[i][PARENT_KEY]]) // for dirty data
      {
        map[data[i][PARENT_KEY]][CHILDREN_KEY].push(data[i]); // add child to parent
        data.splice( i, 1 ); // remove from root
        i--; // iterator correction
      } else {
        data[i][PARENT_KEY] = 0; // clean dirty data
      }
    }
  };
  return data;
}

Exapmle: https://jsfiddle.net/kqw1qsf0/17/

(奖励1:节点可以排序,也可以不排序)

(bonus2:不需要第三方库,纯js)

(BONUS3:用户“Elias Rabl”说这是最高效的解决方案,见下面他的回答)

下面就是:

const createDataTree = dataset => {
  const hashTable = Object.create(null);
  dataset.forEach(aData => hashTable[aData.ID] = {...aData, childNodes: []});
  const dataTree = [];
  dataset.forEach(aData => {
    if(aData.parentID) hashTable[aData.parentID].childNodes.push(hashTable[aData.ID])
    else dataTree.push(hashTable[aData.ID])
  });
  return dataTree;
};

下面是一个测试,它可能会帮助你理解解决方案是如何工作的:

it('creates a correct shape of dataTree', () => {
  const dataSet = [{
    "ID": 1,
    "Phone": "(403) 125-2552",
    "City": "Coevorden",
    "Name": "Grady"
  }, {
    "ID": 2,
    "parentID": 1,
    "Phone": "(979) 486-1932",
    "City": "Chełm",
    "Name": "Scarlet"
  }];

  const expectedDataTree = [{
    "ID": 1,
    "Phone": "(403) 125-2552",
    "City": "Coevorden",
    "Name": "Grady",
    childNodes: [{
      "ID": 2,
      "parentID": 1,
      "Phone": "(979) 486-1932",
      "City": "Chełm",
      "Name": "Scarlet",
      childNodes : []
    }]
  }];

  expect(createDataTree(dataSet)).toEqual(expectedDataTree);
});