使用递归创建动态嵌套json对象

时间:2016-05-13 03:56:11

标签: javascript angularjs json recursion recursive-datastructures

我有以下JSON。

[{
    "ID": "Root_1",
    "Name": "Root_1",                   
    "ParentID": "",
    "Sequent": 1
},
{
    "ID": "Root_2",
    "Name": "Root_2",                   
    "ParentID": "",
    "Sequent": 2
},              
{
    "ID": "Root_1_Sub_1_Child_1",
    "Name": "Root_1_Sub_1_Child_1",                 
    "ParentID": "Root_1_Sub_1",
    "Sequent": 1
},
{
    "ID": "Root_1_Sub_1_Child_2",
    "Name": "Root_1_Sub_1_Child_2",                 
    "ParentID": "Root_1_Sub_1",
    "Sequent": 2
},
{
    "ID": "Root_1_Sub_1",
    "Name": "Root_1_Sub_1",                 
    "ParentID": "Root_1",
    "Sequent": 1
}]

我想将我的JSON更改为以下内容。

[{
    "ID": "Root_1",
    "Name": "Root_1",
    "ParentID": "",
    "Sequent": 1,
    "Sub": [{
        "ID": "Root_1_Sub_1",
        "Name": "Root_1_Sub_1",
        "ParentID": "Root_1",
        "Sequent": 1,
        "Sub": [{
            "ID": "Root_1_Sub_1_Child_1",
            "Name": "Root_1_Sub_1_Child_1",
            "ParentID": "Root_1_Sub_1",
            "Sequent": 1            
        },
        {
            "ID": "Root_1_Sub_1_Child_2",
            "Name": "Root_1_Sub_1_Child_2",
            "ParentID": "Root_1_Sub_1",
            "Sequent": 2            
        }]
    }]
},
{
    "ID": "Root_2",
    "Name": "Root_2",                   
    "ParentID": "",
    "Sequent": 2
}]

在我尝试下面之后,结果不是我想要的。

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <script src="./bower_components/angular/angular.min.js"></script>       
    <script>
            angular.module('myApp', [])
            .controller('MyCtrl', function($scope, $http) {

                $scope.ProjectCategoryList_FlatStyle = [{
                    "ID": "Root_1",
                    "Name": "Root_1",                   
                    "ParentID": "",
                    "Sequent": 1
                },
                {
                    "ID": "Root_2",
                    "Name": "Root_2",                   
                    "ParentID": "",
                    "Sequent": 2
                },              
                {
                    "ID": "Root_1_Sub_1_Child_1",
                    "Name": "Root_1_Sub_1_Child_1",                 
                    "ParentID": "Root_1_Sub_1",
                    "Sequent": 1
                },
                {
                    "ID": "Root_1_Sub_1_Child_2",
                    "Name": "Root_1_Sub_1_Child_2",                 
                    "ParentID": "Root_1_Sub_1",
                    "Sequent": 2
                },
                {
                    "ID": "Root_1_Sub_1",
                    "Name": "Root_1_Sub_1",                 
                    "ParentID": "Root_1",
                    "Sequent": 1
                }];


                $scope.ProjectCategoryList_TreeStyle = [];
                $scope.ParentArray = [];
                $scope.ConvertFlatToTree = function(Value){ 
                    angular.forEach(Value, function(item){                      

                            // Create row.                                                  
                            var  _Object = new Object();
                            _Object.ID = item.ID;
                            _Object.Name = item.Name;                           
                            _Object.ParentID = item.ParentID;
                            _Object.Sequent = item.Sequent;
                            _Object.Sub = [];

                            // Checking if it is root element.
                            if(item.ParentID){
                                // It is for child node.
                                // Get Parent Element.
                                var ParentElement = $scope.ParentArray.filter(function (x) { return x.ID === item.ParentID; });
                                ParentElement[0].Sub.push(_Object);
                                $scope.ParentArray.push(_Object);                               
                            }else{
                                // It is for parent node.
                                // Get child elements.
                                var ChildElementArray = $scope.ProjectCategoryList_FlatStyle.filter(function (x) { return x.ParentID === item.ID; });
                                if(ChildElementArray.length != 0){                                  
                                    $scope.ParentArray.push(_Object);
                                    $scope.ProjectCategoryList_TreeStyle.push(_Object); 
                                    $scope.ConvertFlatToTree(ChildElementArray);
                                }
                            }
                   })
                   console.log("ProjectCategoryList_TreeStyle = ", JSON.stringify($scope.ProjectCategoryList_TreeStyle));
                }
                $scope.ConvertFlatToTree($scope.ProjectCategoryList_FlatStyle);
            });
    </script>   
</head>
<body ng-app="myApp" ng-controller="MyCtrl">    
</body>
</html>

以下是我的最终结果。

[{
    "ID": "Root_1",
    "Name": "Root_1",
    "ParentID": "",
    "Sequent": 1,
    "Sub": [{
        "ID": "Root_1_Sub_1",
        "Name": "Root_1_Sub_1",
        "ParentID": "Root_1",
        "Sequent": 1,
        "Sub": [{
            "ID": "Root_1_Sub_1_Child_1",
            "Name": "Root_1_Sub_1_Child_1",
            "ParentID": "Root_1_Sub_1",
            "Sequent": 1,
            "Sub": []
        },
        {
            "ID": "Root_1_Sub_1_Child_2",
            "Name": "Root_1_Sub_1_Child_2",
            "ParentID": "Root_1_Sub_1",
            "Sequent": 2,
            "Sub": []
        }]
    },
    {
        "ID": "Root_1_Sub_1",
        "Name": "Root_1_Sub_1",
        "ParentID": "Root_1",
        "Sequent": 1,
        "Sub": []
    }]
}]

Plunker

1 个答案:

答案 0 :(得分:4)

这是您的解决方案。但是,如果您更好地使用ID和parentID命名约定,那可能会好得多。我没有进行大量的递归运行,而是先对输入数据进行排序,然后按顺序完成作业。

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var flat = [{
    "ID": "Root_1",
    "Name": "Root_1",                   
    "ParentID": "",
    "Sequent": 1
},
{
    "ID": "Root_2",
    "Name": "Root_2",                   
    "ParentID": "",
    "Sequent": 2
},              
{
    "ID": "Root_1_Sub_1_Child_1",
    "Name": "Root_1_Sub_1_Child_1",                 
    "ParentID": "Root_1_Sub_1",
    "Sequent": 1
},
{
    "ID": "Root_1_Sub_1_Child_2",
    "Name": "Root_1_Sub_1_Child_2",                 
    "ParentID": "Root_1_Sub_1",
    "Sequent": 2
},
{
    "ID": "Root_1_Sub_1",
    "Name": "Root_1_Sub_1",                 
    "ParentID": "Root_1",
    "Sequent": 1
}];
function nested(f){
  return f.sort((a,b) => a.ID.length < b.ID.length ? 1 : a.ID.length == b.ID.length ? a.ID < b.ID ? -1 : 1 :-1)
          .reduce((p,c,i,a) => {var parent = !!c.ParentID && a.find(e => e.ID === c.ParentID);
                                !!parent ? !!parent.Sub && parent.Sub.push(c) || (parent.Sub=[c]) : p.push(c);
                                return p;},[]);
};
document.write("<pre>" +  JSON.stringify(nested(flat),null,2) + "</pre>");
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根据你的评论,我确定找到一个解决方案来嵌套一个平面阵列,当父母关系以外没有其他信息时。我的意思是数组项属性可以是两种类型。

[{id: AY998, pid: FT497}, {id: SS113, pid: MN857}, {id: MN857, pid: "root"}, {id: FT497...

其中id是元素的id,pid是父ID,有些对象是root,没有其​​他信息,如level等。

因此,我们的想法是在父母的资历上对数组进行排序,这意味着在其子女之后不会列出父母。因此,一旦完成排序,就可以通过反向迭代轻松完成嵌套。

好的,让我们创建一个包含100种这种性质的混乱数组。 (我实际上必须创建这样的代码来生成具有唯一ID和正确父母关系的项目的数据数组。让我们看看代码

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var flat = [
      { id: 'KR807', pid: 'UT731' },
      { id: 'DW402', pid: 'root' },
      { id: 'ID042', pid: 'RR203' },
      { id: 'ZT645', pid: 'CP292' },
      { id: 'LD796', pid: 'WI018' },
      { id: 'KH280', pid: 'JO343' },
      { id: 'EC894', pid: 'DX943' },
      { id: 'CR293', pid: 'VT921' },
      { id: 'XI611', pid: 'RQ903' },
      { id: 'YG388', pid: 'VN945' },
      { id: 'ZL243', pid: 'AA689' },
      { id: 'VK295', pid: 'CM110' },
      { id: 'CD374', pid: 'VK295' },
      { id: 'XO588', pid: 'ZL243' },
      { id: 'OM916', pid: 'WI018' },
      { id: 'JQ797', pid: 'CM110' },
      { id: 'BF782', pid: 'root' },
      { id: 'EK012', pid: 'VK295' },
      { id: 'AD556', pid: 'PK567' },
      { id: 'LA463', pid: 'KJ237' },
      { id: 'EL156', pid: 'MT394' },
      { id: 'VE720', pid: 'YG388' },
      { id: 'MT364', pid: 'CD374' },
      { id: 'JO343', pid: 'RJ027' },
      { id: 'QQ957', pid: 'PY806' },
      { id: 'UT731', pid: 'MT394' },
      { id: 'NA571', pid: 'OM916' },
      { id: 'NK641', pid: 'VT921' },
      { id: 'YX336', pid: 'FN157' },
      { id: 'RO244', pid: 'VT921' },
      { id: 'BJ784', pid: 'NA571' },
      { id: 'RJ027', pid: 'NH992' },
      { id: 'ZZ311', pid: 'EE630' },
      { id: 'CK935', pid: 'DX943' },
      { id: 'GF710', pid: 'PY806' },
      { id: 'WZ371', pid: 'MU258' },
      { id: 'IM089', pid: 'GL915' },
      { id: 'GN046', pid: 'NH992' },
      { id: 'MT394', pid: 'root' },
      { id: 'OC487', pid: 'WI018' },
      { id: 'KQ384', pid: 'AD556' },
      { id: 'VZ391', pid: 'ZS119' },
      { id: 'VT921', pid: 'MT394' },
      { id: 'OP416', pid: 'HT085' },
      { id: 'QU319', pid: 'ID042' },
      { id: 'SG270', pid: 'CP292' },
      { id: 'BG562', pid: 'WJ207' },
      { id: 'DX943', pid: 'NK641' },
      { id: 'II920', pid: 'UT731' },
      { id: 'AX150', pid: 'JO343' },
      { id: 'TO181', pid: 'YG388' },
      { id: 'WI985', pid: 'VK295' },
      { id: 'DU020', pid: 'VK225' },
      { id: 'RQ903', pid: 'EL156' },
      { id: 'EP215', pid: 'PK567' },
      { id: 'CZ627', pid: 'PY783' },
      { id: 'MU258', pid: 'GL915' },
      { id: 'MC556', pid: 'XI611' },
      { id: 'XX495', pid: 'II920' },
      { id: 'KJ237', pid: 'YG388' },
      { id: 'CP292', pid: 'UT731' },
      { id: 'MH665', pid: 'EL156' },
      { id: 'VK225', pid: 'FN157' },
      { id: 'FU290', pid: 'AX150' },
      { id: 'EE630', pid: 'GL915' },
      { id: 'VN945', pid: 'root' },
      { id: 'PK567', pid: 'VT921' },
      { id: 'PY806', pid: 'NH992' },
      { id: 'FN157', pid: 'GL915' },
      { id: 'DB935', pid: 'root' },
      { id: 'WK936', pid: 'ZL243' },
      { id: 'PY783', pid: 'WJ207' },
      { id: 'WJ207', pid: 'RO244' },
      { id: 'UR082', pid: 'VT921' },
      { id: 'AR742', pid: 'CD374' },
      { id: 'LS455', pid: 'IM089' },
      { id: 'GH814', pid: 'EL156' },
      { id: 'DX929', pid: 'II920' },
      { id: 'YR376', pid: 'CD374' },
      { id: 'EJ895', pid: 'XO588' },
      { id: 'ND802', pid: 'FU290' },
      { id: 'ZS119', pid: 'GD350' },
      { id: 'GD350', pid: 'YG388' },
      { id: 'HT085', pid: 'GL915' },
      { id: 'RR203', pid: 'AA689' },
      { id: 'IC103', pid: 'KR807' },
      { id: 'XT553', pid: 'WZ371' },
      { id: 'JZ880', pid: 'EL156' },
      { id: 'AA689', pid: 'EP215' },
      { id: 'TJ550', pid: 'RJ027' },
      { id: 'GL915', pid: 'root' },
      { id: 'BI123', pid: 'GD350' },
      { id: 'LD710', pid: 'JZ880' },
      { id: 'MQ351', pid: 'AD556' },
      { id: 'WI018', pid: 'NH992' },
      { id: 'KC160', pid: 'AD556' },
      { id: 'CM110', pid: 'root' },
      { id: 'OK014', pid: 'GH814' },
      { id: 'FD929', pid: 'VK225' },
      { id: 'NH992', pid: 'PK567' }
];

function construct(ar){
  var lut = {},
   sorted = [];
  function sort(a){
  	var len = a.length,
  	    fix = -1;
  	for (var i = 0; i < len; i++ ){
  	  while (!!~(fix = a.findIndex(e => a[i].pid == e.id)) && fix > i)
            [a[i],a[fix]] = [a[fix],a[i]]; // ES6 swap
  	  lut[a[i].id]=i;
  	}console.log(lut); //check LUT on the console.
  	return a;
  }
  sorted = sort(ar.slice(0)); // don't modify things that don't belong to you :)
  for (var i = sorted.length-1; i >= 0; i--){
  	if (sorted[i].pid != "root") {
  	  !!sorted[lut[sorted[i].pid]].children && sorted[lut[sorted[i].pid]].children.push(sorted.splice(i,1)[0])
  	                                        || (sorted[lut[sorted[i].pid]].children = [sorted.splice(i,1)[0]]);
  	}
  }
  return sorted;
}
document.write("<pre>" + JSON.stringify(construct(flat),null,2) + "</pre>");
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所以它工作得很好而且速度很快。关键是排序算法。如前所述,它根据父母的资历对阵列进行排序,没有孩子可以在它的父母面前出现。这是唯一的条件。但同时它准备了父id的索引的LUT(哈希列表),这样一旦我们开始反向迭代数组(从最后一项到第一项),它就避免了我们对父进行昂贵的搜索。相反,我们会从LUT(查找表)对象中查找它的索引并插入它的子节点(如果有的话)。很快..!

所以这里有repl.it供你玩。