将 json 对象排序到嵌套树中

Question

我正在从 Web 服务中提取两个相关对象 - 文件夹和电子邮件。文件夹具有 ID 和 parentfolder.ID 属性，该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，它指示它是哪个文件夹的子文件夹。

我已经成功创建了一个函数来将电子邮件嵌套在一个平面文件夹结构中：

{
"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来遍历所有文件夹并将它们推送到其父级的 children 数组中。本质上将树诉诸 n 层。我可以忽略任何 type=items，因为它们已经正确嵌套。只需对类型为文件夹的进行排序即可。

有没有人实现了一个 JSON 递归函数来重建一个带有嵌套的 JSON 对象？

感谢您的帮助。

Answer 1

您可以在没有递归的情况下做到这一点。我在某个时候回复了similar question。我相信您可以使用相同的方法（假设您没有前向引用）：

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);        
    }
}

Answer 2

感谢维文。通过他的回答，我找到了一个最终有效的方法的链接。这是最终代码：

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);