node.js - 实例方法中的 Mongoose 种群

Question

我有一个引用其他文档的模型。我希望该模型中有一种方法可以处理引用模型中使用的数据。

'use strict';

var mongoose = require('mongoose')
  , Schema = mongoose.Schema
    , deepPopulate = require('mongoose-deep-populate');

var MainSchema = new Schema({
  childs: [{type:Schema.ObjectId, ref: 'Child'}], //because many-to-one
  startDate: {type: Date, default: Date.now},
  endDate: {type: Date},
});


MainSchema.methods = {

  retrieveChilds: function(callback) {

    // deepPopulation of childs not possible??

    callback(result);
  },
};

MainSchema.plugin(deepPopulate);

module.exports = mongoose.model('Main', MainSchema);

如上面的代码示例所示，retrieveChilds 函数应在当前 Schema 上执行 deepPopulate 函数。这是可能的还是应该发生在模型之外？ (有时会导致重复代码)

Answer 1

Mongoose instance methods , this 是调用该方法的文档实例，因此您可以执行以下操作:

MainSchema.methods = {
  retrieveChilds: function(callback) {
    this.deepPopulate('childs.subject.data', callback);
  },
};

然后调用它:

main.retrieveChilds(function(err, _main) {
    // _main is the same doc instance as main and is populated.
});