Model Presenter

!https://travis-ci.org/crushlovely/model-presenter.png

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

Example

``js
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

`bash
$ 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:

$3

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.

$3

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

`bash
$ npm install
$ npm test
``