JavaScript:如何过滤深度JSON对象

基本上，执行树的深度优先遍历，在每个节点上调用回调函数。 如果该节点是叶节点，并且其 ID 出现在列表中，则克隆指向该叶的分支，但不要重新克隆已克隆的分支的任何部分。

构建树的部分和过滤副本后，您需要清理原始副本。 出于簿记目的，我在此过程中改变了原始树 - 跟踪哪些分支已经被克隆。

编辑：修改代码以过滤树列表，而不仅仅是单个树

var currentPath = [];
function depthFirstTraversal(o, fn) {
    currentPath.push(o);
    if(o.children) {
        for(var i = 0, len = o.children.length; i < len; i++) {
            depthFirstTraversal(o.children[i], fn);
        }
    }
    fn.call(null, o, currentPath);
    currentPath.pop();
}
function shallowCopy(o) {
    var result = {};
    for(var k in o) {
        if(o.hasOwnProperty(k)) {
            result[k] = o[k];
        }
    }
    return result;
}
function copyNode(node) {
    var n = shallowCopy(node);
    if(n.children) { n.children = []; }
    return n;
}
function filterTree(root, ids) {
    root.copied = copyNode(root); // create a copy of root
    var filteredResult = root.copied;
    depthFirstTraversal(root, function(node, branch) {
        // if this is a leaf node _and_ we are looking for its ID
        if( !node.children && ids.indexOf(node.id) !== -1 ) {
            // use the path that the depthFirstTraversal hands us that
            // leads to this leaf.  copy any part of this branch that
            // hasn't been copied, at minimum that will be this leaf
            for(var i = 0, len = branch.length; i < len; i++) {
                if(branch[i].copied) { continue; } // already copied
                branch[i].copied = copyNode(branch[i]);
                // now attach the copy to the new 'parellel' tree we are building
                branch[i-1].copied.children.push(branch[i].copied);
            }
        }
    });
    depthFirstTraversal(root, function(node, branch) {
        delete node.copied; // cleanup the mutation of the original tree
    });
    return filteredResult;
}
function filterTreeList(list, ids) {
    var filteredList = [];
    for(var i = 0, len = list.length; i < len; i++) {
        filteredList.push( filterTree(list[i], ids) );
    }
    return filteredList;
}
var hierarchy = [ /* your data here */ ];
var ids = [1,3];
var filtered = filterTreeList(hierarchy, ids);

您可以使用deepdash扩展中的filterDeep方法进行lodash：

var obj = [{/* get Vijay Jagdale's source object as example */}];
var idList = [2, 3];
var found = _.filterDeep(
  obj,
  function(value) {
    return _.indexOf(idList, value.id) !== -1;
  },
  { tree: true }
);

filtrate对象将是：

[ { title: 'category 1',
    children:
     [ { title: 'subcategory 11',
         children:
          [ { id: 2, title: 'name 2' },
            { id: 3, title: 'name 3' } ] } ] },
  { title: 'category 2',
    children:
     [ { title: 'subcategory 21',
         children: [ { id: 3, title: 'name cat2sub1id3' } ] } ] } ]

这是您的用例的完整工作测试

虽然这是一个老问题，但我会加上我的 2 美分。该解决方案需要通过循环、子循环等进行简单的迭代，然后比较 ID 并生成生成的对象。我有纯javascript和jQuery解决方案。虽然纯javascript适用于上面的例子，但我推荐jQuery解决方案，因为它更通用，并且对对象进行"深度复制"，以防你有大而复杂的对象，你不会遇到错误。

function jsFilter(idList){
  var rsltHierarchy=[];
  for (var i=0;i<hierarchy.length;i++) {
    var currCatg=hierarchy[i];
    var filtCatg={"title":currCatg.title, "children":[]};
    for (var j=0;j<currCatg.children.length;j++) {
  	var currSub=currCatg.children[j];
  	var filtSub={"title":currSub.title, "children":[]}
  	for(var k=0; k<currSub.children.length;k++){
  		if(idList.indexOf(currSub.children[k].id)!==-1)
  		   filtSub.children.push({"id":currSub.children[k].id, "title":currSub.children[k].title});
  	}
  	if(filtSub.children.length>0)
  		filtCatg.children.push(filtSub);
    }
    if(filtCatg.children.length>0)
  	rsltHierarchy.push(filtCatg);
  }
  return rsltHierarchy;
}
function jqFilter(idList){
  var rsltHierarchy=[];
  $.each(hierarchy, function(index,currCatg){
      var filtCatg=$.extend(true, {}, currCatg);
      filtCatg.children=[];
  	$.each(currCatg.children, function(index,currSub){
        var filtSub=$.extend(true, {}, currSub);
  	  filtSub.children=[];
  	  $.each(currSub.children, function(index,currSubChild){
  		if(idList.indexOf(currSubChild.id)!==-1)
  		  filtSub.children.push($.extend(true, {}, currSubChild));
        });
  	  if(filtSub.children.length>0)
  		filtCatg.children.push(filtSub);
      });
      if(filtCatg.children.length>0)
  	  rsltHierarchy.push(filtCatg);
  });
  return rsltHierarchy;
}
//Now test the functions...
var hierarchy = eval("("+document.getElementById("inp").value+")");
var IDs = eval("("+document.getElementById("txtBoxIds").value+")");
document.getElementById("oupJS").value=JSON.stringify(jsFilter(IDs));
$(function() {
   $("#oupJQ").text(JSON.stringify(jqFilter(IDs)));
});

#inp,#oupJS,#oupJQ {width:400px;height:100px;display:block;clear:all}
#inp{height:200px}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
ID List: <Input id="txtBoxIds" type="text" value="[2, 3]">
<p>Input:
<textarea id="inp">[
  {
    "title": "category 1",
    "children": [
      {"title": "subcategory 11",
        "children": [
          {"id": 1, "title": "name 1"},
          {"id": 2, "title": "name 2"},
          {"id": 3, "title": "name 3"}
        ]
      },
      {"title": "subcategory 12",
        "children": [
          {"id": 1, "title": "name 4"}
        ]
      }
    ]
  },
  {
    "title": "category 2",
    "children": [
      {"title": "subcategory 21",
        "children": [
          {"id": 3, "title": "name cat2sub1id3"},
          {"id": 5, "title": "name cat2sub1id5"}
        ]
      },
      {"title": "subcategory 22",
        "children": [
          {"id": 6, "title": "name cat2sub2id6"},
          {"id": 7, "title": "name cat2sub2id7"}
        ]
      }
    ]
  }
]</textarea>
<p>Pure-Javascript solution results:
<textarea id="oupJS"></textarea>
<p>jQuery solution results:
<textarea id="oupJQ"></textarea>

我不会重新发明轮子。我们现在使用对象扫描进行大部分数据处理，它可以很好地解决您的问题。这是如何

// const objectScan = require('object-scan');
const filter = (input, ids) => {
  objectScan(['**[*]'], {
    filterFn: ({ value, parent, property }) => {
      if (
        ('id' in value && !ids.includes(value.id))
        || ('children' in value && value.children.length === 0)
      ) {
        parent.splice(property, 1);
      }
    }
  })(input);
};
const hierarchy = [ { title: 'category 1', children: [ { title: 'subcategory 1', children: [ { id: 1, title: 'name 1' }, { id: 2, title: 'name 2' }, { id: 3, title: 'name 3' } ] }, { title: 'subcategory 2', children: [ { id: 1, title: 'name 4' } ] } ] }, { title: 'category 2', children: [] } ];
filter(hierarchy, [2, 3]);
console.log(hierarchy);
// => [ { title: 'category 1', children: [ { title: 'subcategory 1', children: [ { id: 2, title: 'name 2' }, { id: 3, title: 'name 3' } ] } ] } ]

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

<script src="https://bundle.run/object-scan@13.8.0"></script>

免责声明：我是对象扫描的作者