Mongoose Subpopulate
Mongoose-subpopulate was created for my needs on SpanDeX.io. It's monkey-patch of the populate Mongoose library for using MongoDB in Node.js apps. Subpopulate allows you to nest populate calls.
It allows you to do this:
m.User.find({}).populate('best_friend').populate('best_friend.best_friend').exec(function (err, result) {
console.log("My BFF's BFF: ", result.best_friend.best_friend.username);
});
Mongoose-subpopulate also allows you to ignore "err" in your callbacks:
m.User.find({}).populate('best_friend').populate('best_friend.best_friend').exec(function (result) {
console.log("My BFF's BFF: ", result.best_friend.best_friend.username);
});
... and if you don't handle the errors, Mongoose-subpopulate will. Use a global exception handler like webkit-devtools-agent if you plan to do this.
Mongoose-subpopulate also handles ObjectIDs better than vanilla mongoose, and allows you to save a sub-object to another object without fear of it being cast to an ObjectId, as with vanilla Mongoose.
Mongoose-subpopulate supports Mongoose 3.x and Mongoose 2.7.
Installation
You know the drill:
npm install mongoose-subpopulate
Look at example.js to see how I use mongoose-subpopulate.