Add sort_by and direction option for HasMany field (thoughtbot#810)

* Add `sort_by` and `direction` options to HasMany field
* Add spec for `sort_by` and `direction` in HasMany field
* [Docs] Add instructions for HasMany sort_by and direction options

docs/customizing_dashboards.md

@@ -74,6 +74,10 @@ which are specified through the `.with_options` class method:
 `:limit` - Set the number of resources to display in the show view. Default is
 `5`.
 
+`:sort_by` - What to sort the association by in the show view.
+
+`:direction` - What direction the sort should be in, `:asc` (default) or `:desc`.
+
 **Field::Number**
 
 `:decimals` - Set the number of decimals to display. Defaults to `0`.

lib/administrate/field/has_many.rb

@@ -1,5 +1,6 @@
 require_relative "associative"
 require "administrate/page/collection"
+require "administrate/order"
 
 module Administrate
   module Field
@@ -37,7 +38,7 @@ def permitted_attribute
       end
 
       def resources(page = 1)
-        data.page(page).per(limit)
+        order.apply(data).page(page).per(limit)
       end
 
       def more_than_limit?
@@ -58,6 +59,18 @@ def candidate_resources
       def display_candidate_resource(resource)
         associated_dashboard.display_resource(resource)
       end
+
+      def order
+        @_order ||= Administrate::Order.new(sort_by, direction)
+      end
+
+      def sort_by
+        options[:sort_by]
+      end
+
+      def direction
+        options[:direction]
+      end
     end
   end
 end

spec/factories.rb

@@ -2,6 +2,16 @@
   factory :customer do
     sequence(:name) { |n| "Customer #{n}" }
     email { name.downcase.gsub(" ", "_") + "@example.com" }
+
+    transient do
+      order_count 3
+    end
+
+    trait :with_orders do
+      after(:create) do |customer, evaluator|
+        create_list(:order, evaluator.order_count, customer: customer)
+      end
+    end
   end
 
   factory :line_item do
@@ -14,7 +24,7 @@
   factory :order do
     customer
     address_line_one "85 2nd St"
-    address_line_two "#700"
+    sequence(:address_line_two) { |n| "#700 (#{n})" }
     address_city "San Francisco"
     address_state "CA"
     address_zip "94110"

spec/lib/fields/has_many_spec.rb

@@ -106,22 +106,58 @@
   describe "#resources" do
     it "limits the number of records shown" do
       limit = Administrate::Field::HasMany::DEFAULT_LIMIT
-      resources = MockRelation.new([:a] * (limit + 1))
+      customer = FactoryGirl.create(:customer, :with_orders, order_count: 10)
+      resources = customer.orders
 
       association = Administrate::Field::HasMany
-      field = association.new(:customers, resources, :show)
+      field = association.new(:orders, resources, :show)
 
-      expect(field.resources).to eq([:a] * limit)
+      expect(field.resources.size).to eq(limit)
     end
 
     context "with `limit` option" do
       it "limits the number of items returned" do
-        resources = MockRelation.new([:a, :b, :c])
+        customer = FactoryGirl.create(:customer, :with_orders)
+        resources = customer.orders
 
         association = Administrate::Field::HasMany.with_options(limit: 1)
-        field = association.new(:customers, resources, :show)
+        field = association.new(:orders, resources, :show)
+
+        expect(field.resources).to be_one
+      end
+    end
+
+    context "with `sort_by` option" do
+      it "returns the resources in correct order" do
+        customer = FactoryGirl.create(:customer, :with_orders)
+        options = { sort_by: :address_line_two }
+        association = Administrate::Field::HasMany.with_options(options)
+        field = association.new(:orders, customer.orders, :show)
+
+        correct_order = customer.orders.sort_by(&:address_line_two).map(&:id)
+        reversed_order = customer.orders.sort do |a, b|
+          b.address_line_two <=> a.address_line_two
+        end
+
+        expect(field.resources.map(&:id)).to eq correct_order
+        expect(field.resources.map(&:id)).to_not eq reversed_order.map(&:id)
+      end
+    end
+
+    context "with `direction` option" do
+      it "returns the resources in correct order" do
+        customer = FactoryGirl.create(:customer, :with_orders)
+        options = { sort_by: :address_line_two, direction: :desc }
+        association = Administrate::Field::HasMany.with_options(options)
+        field = association.new(:orders, customer.orders, :show)
+
+        reversed_order = customer.orders.sort_by(&:address_line_two).map(&:id)
+        correct_order = customer.orders.sort do |a, b|
+          b.address_line_two <=> a.address_line_two
+        end
 
-        expect(field.resources).to eq([:a])
+        expect(field.resources.map(&:id)).to eq correct_order.map(&:id)
+        expect(field.resources.map(&:id)).to_not eq reversed_order
       end
     end
   end