Mongo JavaScript Object Modeler

MongoJSOM is a lightweight MongoDB object modeling library for node.js. It uses mongojs as backend API, and expands from there by providing classes for Models and Schemas.

For basic usage, refer to the mongojs API documentation. In addition to the MongoDB API calls, MongoJSOM provides object modeling capabilities.

Usage

// Require libraries and initiate database connection
var db = require('mongojsom')(connectionString);

// Define your schema
var schema = new db.Schema({
  firstName: String,
  lastName: String
});

// Instantiate your Model class for the 'users' collection
var User = new db.Model('users', schema);

Now that your Model class is instantiated, you can use model prototype methods:

var user = new User({firstName: 'John', lastName: 'Doe'});
user.save(function(err, savedUser) { ... });
user.remove(function(err, wasRemoved) { ... });

You also have access to static collection methods:

User.findOne({firstName: 'John'}, function(err, user) {
  // `user` is an instance of `User`
  user.remove(...);
});

Hooks

You can add hooks to a Model class to run functions on any given document prior to it being saved. This allows you to modify documents before sending them to MongoDB. To add pre-save hooks:

User.pre('save', function(next) {
  this.password = _hashPasswd(this.password);
  next();
});

The document to be saved is bound directly to this. Pre-save methods have a single argument next, which is a callback, to allow for asynchronous operations.

Pre-save hooks are run in the order they were registered, and the changes to a document are cumulative.

Augments

You can augment a model with methods and properties from a different object. Think of augments as mixins with extend capabilities. The way this works is different for each attribute type:

Arrays get unioned:

Foo._arr = ['foo', 'bar'];
Bar._arr = ['bar', 'baz'];
db.Model.augment(Foo, Bar);
Foo._arr == ['foo', 'bar', 'baz'];

Objects get extended:

Foo._obj = {foo: 1, bar: 2};
Bar._obj = {bar: 3, baz: 4};
db.Model.augment(Foo, Bar);
Foo._obj == {foo: 1, bar: 3, baz: 4};

Functions get wrapped:

Foo._fn = function() { this._count++; return 'foo'; };
Bar._fn = function() { this._count++; return 'bar'; };
db.Model.augment(Foo, Bar);
Foo._fn() == 'bar'; // this._count == 2;

Everything else is just replaced. If the property doesn't exist in the original object, it is added. This applies for both static and prototype properties.

Events

The Model class itself is evented. This means that you can listen to events on the static class, rather than on instances. This allows for more complex modeling behavior. Following the example above:

User.on('save', function(user) {
  // This is fired whenever a `user.save()` is called. The `user` argument is
  // the same model instance on which `.save()` was called.
});

Events emitted by default are save and remove, but you can also emit any custom event by doing:

User.emit('myCustomEvent', dataToSend);

See the API documentation for a list of all static collection methods.

seelio/mongojsom

Mongo JavaScript Object Modeler

Usage

Hooks

Augments

Events