从物化路径构建 JSON 树

Question

我打算在 MongoDB 中使用物化路径来表示一棵树，并且需要将物化路径转换回 JSON 树。

例如。 // 实体化路径

var input = [
    {"id": "0", "path": "javascript" },
    {"id": "1", "path": "javascript/database" },
    {"id": "2", "path": "javascript/database/tree" },
    {"id": "3", "path": "javascript/mvc" },
    {"id": "4", "path": "javascript/mvc/knockout.js"},
    {"id": "5", "path": "javascript/mvc/backbone.js"},
    {"id": "6", "path": "c++" },
    {"id": "7", "path": "c++/c0xx"},
    {"id": "8", "path": "c++/c0xx/lambda expressions"},
    {"id": "9", "path": "c++/c0xx/vc10" }
];

结果是：

[
    {
        "id": "0",
        "name": "javascript",
        "children": [
            {
                "id": "1",
                "name": "database",
                "children": [
                    {
                        "id": "2",
                        "name": "tree",
                        "children": []
                    }
                ]
            },
            {
                "id": "3",
                "name": "mvc",
                "children": [
                    {
                        "id": "4",
                        "name": "knockout.js",
                        "children": []
                    },
                    {
                        "id": "5",
                        "name": "backbone.js",
                        "children": []
                    }
                ]
            }
        ]
    },
    {
        "id": "6",
        "name": "c++",
        "children": [
            {
                "id": "7",
                "name": "c0xx",
                "children": [
                    {
                        "id": "8",
                        "name": "lambda expressions",
                        "children": []
                    },
                    {
                        "id": "9",
                        "name": "vc10",
                        "children": []
                    }
                ]
            }
        ]
    }
]

我发现Convert delimited string into hierarchical JSON with JQuery 工作正常。

我还发现了Build tree from materialized path，它是用 Ruby 编写并使用递归的。我很感兴趣和好奇地看到它在 Javascript 中实现，并想知道是否有任何人会流利地使用 Ruby 和 Javascript 来重写它。我确实尝试了一个 Ruby 到 JS 的转换器，但结果令人费解。

谢谢， 内维尔

Answer 1

var Comment = new Schema({
    date      : {
        type        : Date,
        default     : Date.now
    },
    event: ObjectId,
    body      : String,
    pathComment  : String,
    user: Array
})
Comment.virtual('level').get(function() {
    return this.pathComment.split(',').length;
});

Comment.find({event: event.id}).sort({pathComment:1}).exec(function(err, comment){

            var collectComment = function(comment){
                return  {
                    body: comment.body,
                    event: comment.event,
                    pathComment: comment.pathComment,
                    id: comment._id,
                    level: comment.level,
                    user: comment.user[0],
                    date: comment.date,
                    comments: []
                };

            }
            var tplComment = [];

            var createChildComment = function(comment, currentNode, level){

                if(level==1){
                    comment.push(collectComment(currentNode));
                }else{
                    createChildComment(comment[comment.length-1]['comments'], currentNode,level-1);
                }
                return;

            }

            for(var k in comment){
               createChildComment(tplComment, comment[k],comment[k].level);
            }
});