将json对象排序到嵌套树中

sort json objects into nested tree

本文关键字：嵌套排序 json 对象更新时间：2023-09-26

我正在从web服务中提取两个相关的对象——文件夹和电子邮件。文件夹有一个ID和一个父文件夹。ID属性，指示文件夹嵌套在哪个父文件夹下。电子邮件有一个CategoryID，指示它是哪个文件夹的子文件夹。

我已经成功地创建了一个将电子邮件嵌套在平面文件夹结构中的功能：

{
"folders": [
    {
        "name": "my emails",
        "type": "folder",
        "additionalParameters": {
            "id": "174661",
            "type": "email",
            "parentID": "0"
        },
        "children": [
            {
                "name": "Test1",
                "type": "item",
                "additionalParameters": {
                    "id": "27502",
                    "subject": "Test"
                }
            },
            {
                "name": "Hello",
                "type": "item",
                "additionalParameters": {
                    "id": "27917",
                    "subject": "Hi!"
                }
            }
        ]
    },
    {
        "name": "Test",
        "type": "folder",
        "additionalParameters": {
            "id": "175620",
            "type": "email",
            "parentID": "174661"
        },
        "children": [
            {
                "name": "Test2",
                "type": "item",
                "additionalParameters": {
                    "id": "27891",
                    "subject": "Test"
                }
            }
        ]
    },
    {
        "name": "SubFolder1",
        "type": "folder",
        "additionalParameters": {
            "id": "175621",
            "type": "email",
            "parentID": "175620"
        },
        "children": [
            {
                "name": "Test2",
                "type": "item",
                "additionalParameters": {
                    "id": "27892",
                    "subject": "Test"
                }
            },
            {
                "name": "Test3",
                "type": "item",
                "additionalParameters": {
                    "id": "27893",
                    "subject": "Test"
                }
            }
        ]
    },
    {
        "name": "SubFolder2",
        "type": "folder",
        "additionalParameters": {
            "id": "175622",
            "type": "email",
            "parentID": "175620"
        },
        "children": [
            {
                "name": "Test4",
                "type": "item",
                "additionalParameters": {
                    "id": "27894",
                    "subject": "Test"
                }
            }
        ]
    }
]
}

现在，我需要使用递归循环遍历所有文件夹，并将它们推入其父文件夹的子文件夹数组中。本质上是将树诉诸于n个级别。我可以忽略任何type=items，因为它们已经被适当地嵌套。只需要对那些类型为文件夹的文件进行排序。

有人实现过JSON递归函数来重建带有嵌套的JSON对象吗？

谢谢你的帮助。

您可以在不递归的情况下完成此操作。我曾经回答过一个类似的问题。我相信你可以使用同样的方法（假设你没有前向参考）：

var idToNodeMap = {}; //Keeps track of nodes using id as key, for fast lookup
var root = null; //Initially set our root to null
//loop over data
for(var i = 0; i < data.folders.length; i++) {
    var folder = data.folders[i];
    //each node will have children, so let's give it a "children" poperty
    folder.children = [];
    //add an entry for this node to the map so that any future children can
    //lookup the parent
    idToNodeMap[folder.additionalParameters.id] = folder;
    //Does this node have a parent?
    if(folder.additionalParamters.parentID === "0") {
        //Doesn't look like it, so this node is the root of the tree
        root = folder;        
    } else {        
        //This node has a parent, so let's look it up using the id
        parentNode = idToNodeMap[folder.additionalParamters.parentID];    
        //Let's add the current node as a child of the parent node.
        parentNode.children.push(folder);        
    }
}

感谢Vivin。通过他的回答，我找到了一个最终奏效的方法的链接。这是最后的代码：

var arr = $this.folderArray;
                        // Define root
                        console.log("arr");
                        console.log(arr);
                        // Define tree
                        var tree = {
                            root: root
                        };
                        console.log('tree');
                        console.log(tree);
                        // Get parent of node (recursive)
                        var getParent = function (rootNode, rootId) {
                            console.log('rootnode');
                            console.log(rootNode);
                            console.log('rootId');
                            console.log(rootId);
                            if (rootNode.additionalParameters.id === rootId)
                                return rootNode;
                            for (var i = 0; i < rootNode.children.length; i++) {
                                var child = rootNode.children[i];
                                if (child.additionalParameters.id === rootId) return child;
                                if(child.children){
                                    if (child.children.length > 0){
                                        var childResult = getParent(child, rootId);
                                        if (childResult != null) return childResult;
                                    }
                                }
                            }
                            return null;
                        };

                        // Traverse data and build the tree
                        var buildTree = function(tree) {
                            for (var i = 0; i < arr.length; i++) {
                                var elem = arr[i];
                                if (elem.additionalParameters.parentID === "0")
                                    continue;
                                //elem["children"] = [];
                                var rootId = elem.additionalParameters.parentID;
                                var parent = getParent(tree.root, rootId);
                                console.log("parent");
                                console.log(parent);
                                parent.children.push(elem);
                                // Debug info
                               // console.log("Elem: " + elem.name + " with parent_id: " + elem.parentAreaRef.id);
                                //console.log("Got parent with name: " + parent._id);
                            }
                        };
                        buildTree(tree);