Merge branch 'patch-1' of https://github.com/timgremore/kaminari into timgremore-patch-1

lib/kaminari/helpers/action_view_extension.rb

@@ -19,6 +19,31 @@ module Kaminari
       paginator.to_s
     end
 
+    # A simple "Twitter like" pagination link that creates a link to the previous page.
+    #
+    # ==== Examples
+    # Basic usage:
+    #
+    #   <%= link_to_previous_page @items, 'Previous Page' %>
+    #
+    # Ajax:
+    #
+    #   <%= link_to_previous_page @items, 'Previous Page', :remote => true %>
+    #
+    # By default, it renders nothing if there are no more results on the previous page.
+    # You can customize this output by passing a block.
+    #
+    #   <%= link_to_previous_page @users, 'Previous Page' do %>
+    #     <span>At the Beginning</span>
+    #   <% end %>
+    def link_to_previous_page(scope, name, options = {}, &block)
+      params = options.delete(:params) || {}
+      param_name = options.delete(:param_name) || Kaminari.config.param_name
+      link_to_unless scope.first_page?, name, params.merge(param_name => (scope.current_page - 1)), options.reverse_merge(:rel => 'previous') do
+        block.call if block
+      end
+    end
+
     # A simple "Twitter like" pagination link that creates a link to the next page.
     #
     # ==== Examples

spec/helpers/action_view_extension_spec.rb

@@ -16,6 +16,33 @@ describe 'Kaminari::ActionViewExtension' do
     end
   end
 
+  describe '#link_to_previous_page' do
+    before do
+      50.times {|i| User.create! :name => "user#{i}"}
+    end
+    context 'having previous pages' do
+      before do
+        @users = User.page(50)
+      end
+      context 'the default behaviour' do
+        subject { helper.link_to_previous_page @users, 'Previous', :params => {:controller => 'users', :action => 'index'} }
+        it { should be_a String }
+        it { should match /rel="previous"/ }
+      end
+      context 'overriding rel=' do
+        subject { helper.link_to_previous_page @users, 'Previous', :rel => 'external', :params => {:controller => 'users', :action => 'index'} }
+        it { should match /rel="external"/ }
+      end
+    end
+    context 'the first page' do
+      before do
+        @users = User.page(1)
+      end
+      subject { helper.link_to_previous_page @users, 'Previous', :params => {:controller => 'users', :action => 'index'} }
+      it { should_not be }
+    end
+  end
+
   describe '#link_to_next_page' do
     before do
       50.times {|i| User.create! :name => "user#{i}"}