How to convert multiple Mongoose documents? - node.js

Question

Each of my schemas have a method, called toItem() which converts the doc to a more verbose / human-readable form. How can I create a toItems() method to do the same thing for an array of documents?
My example schema:
var mongoose = require('mongoose');
var membershipSchema = new mongoose.Schema({
m : { type: mongoose.Schema.ObjectId, ref: 'member' },
b : { type: Date, required: true },
e : { type: Date },
a : { type: Boolean, required: true }
});
var accountSchema = new mongoose.Schema({
n : { type: String, trim: true },
m : [ membershipSchema ]
});
accountSchema.methods.toItem = function (callback) {
var item = {
id : this._id.toString(),
name : this.n,
members : []
};
(this.m || []).forEach(function(obj){
item.members.push({
id : obj.m.toString(),
dateBegin : obj.b,
dateEnd : obj.e,
isAdmin : obj.a
});
});
return callback(null, item);
};
var accountModel = mongoose.model('account', accountSchema);
module.exports = accountModel;
I've tried using statics, methods, and third-party libraries, but nothing clean works. I would like to keep this as simple / clean as possible and have the toItems() function contained within my model file.
Thank you, in advance.

Answer 1

Your toItem() method is specific to the schema / model. Your toItems() method sounds more like a utility method which can / will be used by all of your models. If so, I would move create the toItems() method inside a utility file. You would simply pass in the array of documents and the utility method would call the individual toItem() method on each document.
For example:
var async = require('async');
var toItems = function (models, callback) {
models = models || [];
if (models.length < 1) { return callback(); }
var count = -1,
items = [],
errors = [];
async.forEach(models, function (model, next) {
count++;
model.toItem(function (err, item) {
if (err) {
errors.push(new Error('Error on item #' + count + ': ' + err.message));
}
else {
items.push(item);
}
next();
});
}, function (err) {
if (err) {
return callback(err);
}
if (errors.length > 0) {
return callback(errors[0]);
}
return callback(null, items);
});
};
module.exports.toItems = toItems;