modella

Highly extendable bloat-free models.

Installation

With node.js:

npm install modella

In the browser (using component):

component install modella/modella

Philosophy

modella is a bare bones model. It exposes a few APIs on which plugins can be built to enhance functionality. Usage of these plugins enables high-powered but bloat free models.

Check out the list of available plugins

Defining Models

All modella definition methods are chainable.

modella( name )

Creates a new model with the name name.

var modella = require('modella');
var User = modella('User');

Model.use ( [env], fn )

As mentioned in the philosophy, modella's goal is to make it easy to extend models with plugins. This lets you create models that do exactly what you need, and nothing more. You can use env to target the client and the server separately.

var modella = require('modella');
var validators = require('modella-validators');
var User = modella('User');
 
User.use(validators);

Browser plugin:

User.use('client', plugin);
// or
User.use('browser', plugin);

Server plugin:

User.use('server', plugin);
// or
User.use('node', plugin);

Model.attr( name, [options] )

Adds attribute attrName to a model. Additional options can be passed in as an object. Modella itself accepts the option defaultValue to specify the default value for the attribute. Plugins may extend the available options.

var modella = require('modella'),
var validators = require('modella-validators'),
var User = modella('User');
 
User.use(validators);
 
User
  .attr('_id')
  .attr('username', { required: true })
  .attr('email', { required: true, format: 'email' })
  .attr('admin', { defaultValue: false };
 
var user = new User({
    username: 'bob',
    email: '[e-mail]'
});
// user.admin() === false
var adminUser = new User({
    username: 'bobs_boss',
    email: '[e-mail]',
    admin: true
})
// adminUser.admin() === true

Model.validate( fn )

Adds a validator to the model. A validator should add error messages for attributes that fail validation. Note that plugins such as modella/validators make extensive use of this.

var User = modella('User');
 
User.validate(function(user) {
  if(!user.username()) {
    user.error('username', "is required");
  }
});

Working with Instances

new Model( [attrs] )

You can create instances of models with the new operator. You can also specify initial values by passing in an object for attrs.

var user = new User();
 
var bob = new User({username: 'Bob' });

Model#attribute(value)

Sets the given attribute to a value. Passing undefined will unset the attribute.

var user = new User();
 
user.username("Bob");

Model#attribute()

Returns the value of the attribute

var user = new User({username: 'Bob'});
 
user.username() // => 'Bob'

Model#get( attr )

Returns the value of the attribute

var user = new User({username: 'Bob'});
 
user.get('username') // => 'Bob'

Model#unset( attr )

Unset the attribute

var user = new User({username: 'Bob', age: 27});
 
user.unset('username');
 
// user.username() === undefined

Model#has( attr )

Returns whether an instance has an attribute set.

var user = new User({username: 'Bob'});
 
user.has('email') // => false

Model#set( attrs )

Quickly sets multiple attributes. Using undefined for a value will unset the attribute.

var user = new User();
 
user.set({username: 'Bob', email: '[e-mail]'});

Model#primary( [key] )

Gets or sets the value of the primary key attribute. By default, this auto-maps to an attribute with the name of _id or id if it is specified.

Getting the primary key:

var User = modella('User').attr('_id');
var user = new User({_id: 123 });
 
user.primary(); // => 123

Setting the primary key:

var User = modella('User').attr('_id');
var user = new User({_id: 123 });
user.primary(456);
 
user.primary(); // => 456

Model#isNew()

Returns a boolean based on if the value of Model#primary() is set or not.

var user = new User();
user.isNew() // => true
 
var oldUser = new User({_id: 555});
oldUser.isNew() // => false

Model.isValid()

Runs all validators on the model and returns whether any validations failed.

var User = modella('User')
var validators = require('modella-validators');
 
User
  .attr('username', { required: true })
  .use(validators);
 
var user = new User();
 
user.isValid() // => false

Model#save( [fn(err)] )

Saves the model using the syncLayer. Will not attempt to save if model#isValid() returns false.

Calls fn(err) after save.

var User = modella('User')
  .attr('_id')
  .attr('name');
 
var user = new User({ name: 'Charley' });
 
user.save(function(err) {
  // ...
});

Using events:

user.on('save', function() {
  // all good!
});
 
user.on('error', function(err) {
  // oh no!
});
 
user.save();

Model#remove( [fn(err)] )

Deletes the model using the sync layer and marks it as removed.

Calls fn(err) after remove.

Model#removed

Marked as true if the model has been deleted.

user.remove(function(err) {
  // ...
});
 
user.removed // => true

Model#model

Points to the base model from which the instance was created.

var user = new User();
 
user.model === User // => true

Model#json()

Model#toJSON()

Gets the JSON representation of the model

Writing Plugins

Modella is made to be extended! Use events to hook into modella and manipulate the data as necessary. See below for the list of events.

For types of plugins, and more comprehensive documentation, see the plugin writing guide.

Here's some existing plugins to help you get started: list of available plugins.

Events

All modella models have built in emitters on both instances and the model itself.

You can listen for an event on either the instance of a model or the Model itself. Here's how to listen on the instance:

var user = new User()
 
user.on('save', function() {
  user.remove();
});

Listening on the Model is useful for performing aggregate operations on all instances. Here's how to listen on the Model:

User.on('save', function(user) {
  // user is the instance that performed save
});

List of All Events

Save Events

• save triggers after a successful save.
• create triggers after a record is saved for the first time.
• saving triggers before saving has occurred. saving requires asynchronous callbacks so that validation can occur.

Asynchronous callback:

user.on('saving', function(done) {
  // ...
  done();
});
 
User.on('saving', function(user, done) {
  // ...
  done();
});

Remove Events

• remove: triggers after a successful removal.
• removing: triggers before a remove has occurred. removing must call an asynchronous callback so that execution can continue

Asynchronous callback:

user.on('removing', function(done) {
  // ...
  done();
});
 
User.on('removing', function(user, done) {
  // ...
  done();
});

Validation Events

• invalid triggers when isValid() or validate() fails.
• valid triggers when isValid() or validate() passes.

Manipulation Events

• change <attr> triggers when attr changes (via set or model.attr(val).

user.on('change name', function(val, prev) {
  // ...
})
 
user.name('charley');

• initializing triggers when a new instance is created. Passes attrs which can be modified by the listener.

User.on('initializing', function(instance, attrs) {
  attrs.name = attrs.name.toUpperCase();
});
 
var bob = new User({name: 'Bob'});
bob.name() // => BOB

• setting triggers when instance.set is called. Passes attrs which can be modified in the listener.

User.on('setting', function(instance, attrs) {
  attrs.name = attrs.name.toUpperCase();
});
var bob = new User();
bob.set({name: 'Bob'});
bob.name() // => BOB

Miscellaneous Events

• attr triggers when a new attribute is added/changed (Model.attr(name, options))
• initialize triggers when a model has been completely initialized.
• error triggers whenever there's an error syncing the model.

License

(The MIT License)

Copyright (c) 2013 Ryan Schmukler [e-mail]

Copyright (c) 2013 Matthew Mueller [e-mail]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.