mongoose-plugin-deep-populate

DeepPopulate plugin helps you do some auto population without thinking about depth, inspired from mongoose-autopopulate.

Installation

Just run

npm install mongoose-plugin-deep-populate

or

yarn add mongoose-plugin-deep-populate

And just call it from a model created JavaScript file

const mongoose = require('mongoose');
 
const schema = new mongoose.Schema({
  ...
});
 
schema.plugin(require('./mongoose-plugin-deep-populate'));

Or install it for all schemas

const mongoose = require('mongoose');
 
mongoose.plugin(require('./mongoose-plugin-deep-populate'));

Usage

Let's create a School model

const SchoolSchema = new mongoose.Schema(
  {
    name: {
      type: String
    },
  },
);
 
const School = mongoose.model('school', SchoolSchema);

And Student model

const StudentSchema = new mongoose.Schema(
  {
    firstName: { type: String },
    lastName: { type: String },
    school: {
      type: Mongoose.SchemaTypes.ObjectId,
      ref: 'school',
    },
  },
);
 
const Student = mongoose.model('student', StudentSchema);

And ExamMark model

const ExamMarkSchema = new mongoose.Schema(
  {
    student: {
      type: Mongoose.SchemaTypes.ObjectId,
      ref: 'student',
    },
    mark: {
      type: Number,
    }
  },
);
 
const ExamMark = mongoose.model('exammark', ExamMarkSchema);

And the only think we have to do to use the deep population plugin is add the deepPopulate option field

const ExamMarkSchema = new mongoose.Schema(
  {
    ...
  },
  {
    deepPopulate: {
      student: {
        school: true,
      },
    },
  },
);

Or you want to populate only one deep level, you can also do

const ExamMarkSchema = new mongoose.Schema(
  {
    ...
  },
  {
    deepPopulate: ['student'],
  },
);

And just call

const examMark = await ExamMark.findOne({ _id: '...' });

And with doing that every time a query runs on ExamMark model, student and school of student fields automatically populated as nested. Now, deepPopulation only works on the queries on ExamMark model, since we add options to the only ExamMark model. Any query runs on Student model does not populate school field since we have not add the deepPopulation field to the student model.

---

To skip the deep population step, just use skipPopulation function

const examMark = await ExamMark.findOne({ _id: '...' }).skipPopulation(true);

Default value of the skipPopulation function parameters is true, so you can also do

const examMark = await ExamMark.findOne({ _id: '...' }).skipPopulation();