Model Presenter

A lightweight model wrapper to prepare your data for the view layer.

Example

var Presenter = require('model-presenter');

var PersonPresenter = Presenter.extend({

  customAttributes: {
    fullName: function() {
      return this.attributes.firstName + ' ' + this.attributes.lastName;
    },
    fullNameAllCaps: function() {
      return this.customAttribute('fullName').toUpperCase();
    }
  },

  strategies: {
    avatar: {
      whitelist: ['image', 'username'],
      customAttributes: ['fullNameAllCaps']
    },
    profile: {
      blacklist: ['ssn'],
      customAttributes: ['fullName']
    },
    chat: {
      whitelist: ['image', 'username', 'memberSince']
    }
  }

})

var person = {
    image: 'image.jpeg',
    username: 'createbang',
    firstName: 'Michael',
    lastName: 'Phillips',
    ssn: '111-11-1111',
    memberSince: '2013-01-01'
};

PersonPresenter.present( person ) // returns full representation of object including custom attributes
PersonPresenter.present( person, 'avatar' ) // returns {image: 'image.jpeg', username: 'createbang', fullNameAllCaps: 'MICHAEL PHILLIPS'}
PersonPresenter.present( person, 'profile' ) // returns all model data except ssn and adds fullName custom attribute
PersonPresenter.present( person, 'chat' ) // returns just the whitelisted keys

Adapters

Presenters can be used out of the box, or you can use any of the adapters listed below for the framework you use:

• backbone-presenter for Backbone.js

Installation

via npm

$ npm install model-presenter

Presenter Properties

Presenters constructors are defined as extensions of the base Presenter object, defining custom attributes or display strategies.

Presenters have two primary properties:

customAttributes

The customAttributes property allows you to specify presentation-only model values.

Each attribute is defined as a function. The returned value will be used as the value of that attribute. The scope for each function contains two properties:

attributes

surfaces all properties of the native model (delegates to the serializer method, if defined, to generate values).

customAttribute

A function that allows access to other custom attributes. Takes the name of the custom attribute as the argument.

strategies

The strategies object allows you to define specific representation strategies for the presenter. This lets the developer define a presentation for the model once and easily use it elsewhere in the application.

Each strategy accepts three properties:

whitelist

An array of keys to pick from the original model data.

blacklist

An array of keys to omit from the original model data.

customAttributes

An array of custom attribute keys to add to the resulting object

present

The Presenter class exposes a method present that accepts two arguments

• model a single model object. This can also be an array of objects, or a collection
• strategy (optional) the presenter strategy to use

The present method returns a raw JavaScript object (or array of objects) that have been converted through the presenter.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Running tests

$ npm install
$ npm test