Model validation

item.coffee

# My model
class exports.Item extends Backbone.Model
  validation:
    item:
      required: true
    quantity:
      required: true
      pattern: 'number'
    price:
      required: true
      pattern: 'number'

itemView.coffee

#Part of the view
class exports.ItemView extends Backbone.View
  tagName: 'tr'

  events:
...

  initialize: ->
    @model.bind('change' , @render, @)
    @model.bind('destroy', @remove, @)
    Backbone.Validation.bind @,
      valid: (view,attr) ->
        view.$('#' + attr).removeClass('error')
      invalid: (view,attr,error) ->
        view.$('#' + attr).addClass('error')