Schema 中的递归元素:Mongoose 建模

Recursive elements in Schema : Mongoose modelling

知道如何在 Mongoose Schema 中为树文档建模吗?

var TreeSchema = new Schema({
    "Non-leafNode": {
        "children": [
            {
                "type": "NodeElement"
            }
        ]
    },
    "NodeElement": {
        // one of them is required. not both.
        "elem": {
            "type": "LeafNode"
        },
        "elem2": {
            "type": "Non-leafNode"
        }
    },
    "LeafNode": {}
});

如何模拟这个?整个树是一个文档(理想情况下)。

来自https://groups.google.com/forum/#!topic/mongoose-orm/0yUVXNyprx8

By design, it might work. There's no tests for this. I have Schema#add in there for this purpose, to produce recursive references:

var Tasks = new Schema();
Tasks.add({
   title     : String
 , subtasks  : [Tasks]
});

所以需要一步步构造递归