Esboço de filtros para collections em js

filters.js.coffee

define 'algumacoisa/filters', (), [] ->
	class SomeFilteredCollectionCoordinator
		initialize: ->
			@filterGroups = [
		  		new Filters.Group('has_rsvped', [
		  			new Filters.Choice(when: false, selected: true),
		  			new Filters.Choice(when: true)
		  		]),
		  		new Filters.Group('arrived_at', [
		  			new Filters.Choice(with: _.isNull, when: false ),
		  			new Filters.Choice(with: _.isNull, when: true, selected: true)
		  		]),
		  		new Filters.Group('invitee_gender', [
		  			new Filters.Choice(when: 'male' ),
		  			new Filters.Choice(when: 'female'),
		  			new Filters.Choice(when: 'transgender')
		  		])
			]

			new InvitationsCollection(filterGroups: @filterGroups)


define "helpers/filter", [], ->
	class FilterGroup
		matches : (model) ->
			_.some @choices, (choice) -> # group filters with an "or" clause
				!choice.selected? ||
				choice.matches( model.get(@attributeName) )

	class EqualityFilter
		initialize: ({@when, @with, @selected}) ->

		matches: (attributeValue) ->
			@with(attributeValue) == @when

	{
		Group: FilterGroup,
		Equality: EqualityFilter
	}