mongoose-fill-promises

mongoose-fill-promises is mongoose.js add-on that adds simple api for virtual async fields.

why?

This just gives you a simple and easy to use API for:

- implementing db joins without keeping refs to related objects (with refs you can use populate)
- joining mongoose object with any kind of data (with any async service - other db or web service)

version support - breaking changes

Version 2.0.0 of this library is written as an ESM, and works with mongoose 7.0.0 and above, and requires node 20.0.0 or above.

For compatibility with mongoose < 7 and node < 20 use version 1.x.

This is a fork of mongoose-fill which has been archived. Mongoose 7 dropped support for the callback api on queries so this version was modified to use promises.

api use cases - learn by example

basic use case fills single filed

``javascript
// import of 'mongoose-fill-promises' patches mongoose and returns mongoose object, so you can do:
var mongoose = require('mongoose-fill-promises')
...
// note you should set virtual properties options
// on you schema to get it mongoose-fill-promises 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)

$3

npm install mongoose-fill-promises

$3

npm test