Filter facets

lib/hal_api/controller/filtering.rb

@@ -53,6 +53,24 @@ def filters
     @filters ||= parse_filters_param
   end
 
+  def filter_facets
+  end
+
+  def index_collection
+    collection = defined?(super) ? super : HalApi::PagedCollection.new([])
+
+    # add facets if defined, removing filters/facets with counts of 0
+    non_zero_facets = (filter_facets || {}).with_indifferent_access.tap do |hash|
+      hash.each do |filter_key, facets|
+        hash[filter_key] = facets.try(:select) { |f| f.try(:[], :count) > 0 }
+        hash.delete(filter_key) if hash[filter_key].blank?
+      end
+    end
+    collection.facets = non_zero_facets unless non_zero_facets.blank?
+
+    collection
+  end
+
   private
 
   def parse_filters_param

lib/hal_api/controller/resources.rb

@@ -75,6 +75,10 @@ def resources_base
     self.class.resource_class.where(nil)
   end
 
+  def resources_query
+    filtered(scoped(resources_base))
+  end
+
   def find_base
     filtered(scoped(included(resources_base)))
   end

lib/hal_api/paged_collection.rb

@@ -6,7 +6,7 @@ class HalApi::PagedCollection
   extend ActiveModel::Naming
   extend Forwardable
 
-  attr_accessor :items, :request, :options
+  attr_accessor :items, :request, :options, :facets
 
   def_delegators :items, :total_count, :prev_page, :next_page, :total_pages, :first_page?, :last_page?
   alias_method :total, :total_count

lib/hal_api/rails/version.rb

@@ -1,5 +1,5 @@
 module HalApi
   module Rails
-    VERSION = "0.6.0"
+    VERSION = "0.7.0"
   end
 end

lib/hal_api/representer.rb

@@ -21,5 +21,6 @@ class HalApi::Representer < Roar::Decorator
   include HalApi::Representer::Caches
   include HalApi::Representer::LinkSerialize
   self_link
+  vary_link
   profile_link
 end

lib/hal_api/representer/collection_paging.rb

@@ -7,6 +7,7 @@ module HalApi::Representer::CollectionPaging
     class_eval do
       property :count
       property :total
+      property :facets
 
       embeds :items, decorator: lambda{|*| item_decorator }, class: lambda{|*| item_class }, zoom: :always
 
@@ -36,6 +37,14 @@ def self_url(represented)
     href_url_helper(represented.params)
   end
 
+  def vary_url(represented)
+    href_url_helper(represented.params.except(*vary_params))
+  end
+
+  def vary_params
+    %w(page per zoom filters sorts)
+  end
+
   def profile_url(represented)
     model_uri(:collection, represented.item_class)
   end
@@ -46,6 +55,7 @@ def profile_url(represented)
   # if it is a lambda, execute in the context against the represented.parent (if there is one) or represented
   def href_url_helper(options={})
     if represented_url.nil?
+      options = options.except(:format)
       result = url_for(options.merge(only_path: true)) rescue nil
       if represented.parent
         result ||= polymorphic_path([:api, represented.parent, represented.item_class], options) rescue nil

lib/hal_api/representer/uri_methods.rb

@@ -21,6 +21,15 @@ def self_link
       end
     end
 
+    def vary_link
+      link(:vary) do
+        {
+          href: vary_url(represented) + vary_query_params,
+          templated: true,
+        } if vary_url(represented).present? && vary_params.present?
+      end
+    end
+
     def profile_link
       link(:profile) { profile_url(represented) }
     end
@@ -46,6 +55,18 @@ def self_url(represented)
     polymorphic_path([:api, rep])
   end
 
+  def vary_url(represented)
+    self_url(represented)
+  end
+
+  def vary_params
+    []
+  end
+
+  def vary_query_params
+    "{?#{vary_params.join(',')}}"
+  end
+
   def becomes_represented_class(rep)
     return rep unless rep.respond_to?(:becomes)
     klass = rep.try(:item_class) || rep.class.try(:base_class)

test/hal_api/controller/filtering_test.rb

@@ -8,10 +8,25 @@ class FilteringTestController < ActionController::Base
     filter_params :one, :two, :three, :four, :five, six: :date, seven: :time
 
     attr_accessor :filter_string
+    attr_accessor :no_facets
 
     def params
       { filters: filter_string }
     end
+
+    def filter_facets
+      {
+        one: [{count: 2}],
+        two: [],
+        three: [
+          {id: 'a', count: 4},
+          {id: 'b', count: 5},
+          {id: 'c', count: 0}
+        ],
+        four: [{count: 0}],
+        five: [{id: 'a', count: 0}]
+      } unless no_facets
+    end
   end
 
   let(:controller) { FilteringTestController.new }
@@ -84,4 +99,24 @@ def params
     err.must_be_instance_of(HalApi::Errors::BadFilterValueError)
   end
 
+  it 'sets facets on the collection' do
+    controller.index_collection.facets[:one].must_equal [{'count' => 2}]
+    controller.index_collection.facets[:three].count.must_equal 2
+    controller.index_collection.facets[:three][0].must_equal({'id' => 'a', 'count' => 4})
+    controller.index_collection.facets[:three][1].must_equal({'id' => 'b', 'count' => 5})
+  end
+
+  it 'removes empty facets' do
+    controller.index_collection.facets.keys.must_include 'one'
+    controller.index_collection.facets.keys.must_include 'three'
+    controller.index_collection.facets[:three].map { |f| f['id'] }.wont_include 'c'
+    controller.index_collection.facets.keys.wont_include 'four'
+    controller.index_collection.facets.keys.wont_include 'five'
+    controller.index_collection.facets.keys.wont_include 'six'
+  end
+
+  it 'does not set facets if there are none' do
+    controller.no_facets = true
+    controller.index_collection.facets.must_be_nil
+  end
 end

test/hal_api/paged_collection_representer_test.rb

@@ -30,6 +30,13 @@
     representer.represented_url.must_equal "api_stories_path"
   end
 
+  it 'has a vary link' do
+    representer.represented.options[:url] = "api_stories_path"
+    json['_links']['vary'].wont_be_nil
+    json['_links']['vary']['href'].must_equal 'api_stories_path{?page,per,zoom,filters,sorts}'
+    json['_links']['vary']['templated'].must_equal true
+  end
+
   it 'uses a lambda for a url method' do
     representer.represented.options[:url] = ->(options){ options.keys.sort.join('/') }
     representer.href_url_helper({foo: 1, bar: 2, camp: 3}).must_equal "bar/camp/foo"