Mongoose.js add-on that adds virtual (temporary) async fileds API
npm install mongoose-fillpopulate)
javascript
// import of 'mongoose-fill' patches mongoose and returns mongoose object, so you can do:
var mongoose = require('mongoose-fill')
...
// note you should set virtual properties options
// on you schema to get it mongoose-fill work
var myParentSchema = new Schema({
....
}, {
toObject: {
virtuals: true
},
toJSON: {
virtuals: true
}
}
myParentSchema.fill('children', function(callback){
this.db.model('Child')
.find({parent: this.id})
.select('name age')
.order('-age')
.exec(callback)
})
...
Parent.findById(1).fill('children').exec().then(function(parent){
//parent.children <- will be array of children with fields name and age ordered by age
})
`
filling property using single query for multiple objects
`javascript
myParentSchema.fill('childrenCount').value(function(callback){
// this is current (found) instance
this.db.model('Child')
.count({parent: this.id})
.exec(callback)
// multi is used for queries with multiple fields
}).multi(function(docs, ids, callback){
// query childrenCount for all found parents with single db query
this.db.model('Child')
.aggregate([{
$group: {
_id: '$parent',
childrenCount: {$sum: 1}
}},
{$match: {'_id': {$in: ids}}}
], callback)
})
...
// you can place property name that should be filled in select option
Parent.find({}).select('name childrenCount').exec().then(function(parents){
//parent.childrenCount <- will contain count of children
})
`
using fill options with default values
`javascript
myParentSchema.fill('children', function(select, order, callback){
this.db.model('Child')
.find({parent: this.id})
.select(select)
.order(order)
.exec(callback)
}).options('', '-age')
...
// fill children with only name age properties ordered by age
Parent.findById(1).fill('children', 'name age', 'age').exec().then(function(parent){
//parent.children <- will be array of children with fields name and age ordered by age
})
`
Also check the code of test for more use cases
how does it work
- adds fill method to mongoose schema object
- adds fill and filled prototype methods to mongoose model
- patches mongoose query exec method extending query api with fill method
- implemented using mongoose virtual setters/getters (actual value is stored in __propName` property)