Simple XML Pagination

lib/will_paginate/view_helpers.rb

@@ -30,9 +30,10 @@ module ViewHelpers
       :separator      => ' ', # single space is friendly to spiders and non-graphic browsers
       :param_name     => :page,
       :params         => nil,
-      :renderer       => 'WillPaginate::LinkRenderer',
+      :renderer       => nil,
       :page_links     => true,
-      :container      => true
+      :container      => true,
+      :xml            => false
     }
     mattr_reader :pagination_options
 
@@ -104,14 +105,17 @@ def will_paginate(collection = nil, options = {})
       end
 
       # get the renderer instance
+      options[:renderer] ||= options[:xml] ? 'WillPaginate::XmlLinkRenderer' : 'WillPaginate::LinkRenderer'
       renderer = case options[:renderer]
       when String
         options[:renderer].to_s.constantize.new
       when Class
         options[:renderer].new
       else
         options[:renderer]
-      end
+      end                      
+
+
       # render HTML for pagination
       renderer.prepare collection, options, self
       renderer.to_html
@@ -251,7 +255,11 @@ def html_attributes
     end
 
   protected
-
+
+    def options
+      @options
+    end
+
     # Collects link items for visible page numbers.
     def windowed_links
       prev = nil
@@ -387,4 +395,14 @@ def stringified_merge(target, other)
       end
     end
   end
+
+  class XmlLinkRenderer < LinkRenderer
+    def to_html
+      buffer = options[:buffer] || ""
+      xml = options[:builder] || Builder::XmlMarkup.new(:target => buffer, :indent => 2, :margin => 1)
+      xml.link :rel => 'next', :href => url_for(@collection.next_page) unless @collection.next_page.nil?
+      xml.link :rel => 'prev', :href => url_for(@collection.previous_page) unless @collection.previous_page.nil?
+      xml.target!
+    end  
+  end
 end

test/view_test.rb

@@ -165,6 +165,64 @@ def test_container_id
     end
   end
 
+  ## XML rendering ##
+
+  def test_xml_pagination_output_with_prev_and_next
+    paginate({:page => 2, :per_page => 5, :total_entries => 22}, :xml => true)
+    expected = <<-XML
+  <link rel="next" href="/foo/bar?page=3" />
+  <link rel="prev" href="/foo/bar?page=1" />
+    XML
+    assert_dom_equal expected, @html_result
+  end
+
+  def test_xml_pagination_output_with_prev_only
+    paginate({:page => 2, :per_page => 5, :total_entries => 10}, :xml => true)
+    expected = <<-XML
+  <link rel="prev" href="/foo/bar?page=1" />
+    XML
+    assert_dom_equal expected, @html_result
+  end
+
+  def test_xml_pagination_output_with_next_only
+    paginate({:page => 1, :per_page => 5, :total_entries => 10}, :xml => true)
+    expected = <<-XML
+  <link rel="next" href="/foo/bar?page=2" />
+    XML
+    assert_dom_equal expected, @html_result
+  end
+
+  def test_xml_pagination_output_with_single_page
+    paginate({:page => 1, :per_page => 5, :total_entries => 5}, :xml => true)
+    expected = ""
+    assert_dom_equal expected, @html_result
+  end
+
+  def test_xml_pagination_output_with_builder                        
+    expected = <<-XML   
+    <navigation>
+        <link rel="next" href="/foo/bar?page=3" />
+        <link rel="prev" href="/foo/bar?page=1" />
+    </navigation>
+    XML
+    xml = Builder::XmlMarkup.new(:indent => 4, :margin => 1)
+    xml.navigation do
+      paginate({:page => 2, :per_page => 5, :total_entries => 22}, {:xml => true, :builder => xml})
+    end
+    assert_dom_equal expected, xml.target!
+  end
+
+  def test_xml_pagination_output_with_buffer                        
+    buffer ="    Result: \n"
+    paginate({:page => 2, :per_page => 5, :total_entries => 22}, {:xml => true, :buffer => buffer})
+    expected = <<-XML
+    Result: 
+  <link rel="next" href="/foo/bar?page=3" />
+  <link rel="prev" href="/foo/bar?page=1" />
+    XML
+    assert_dom_equal expected, buffer
+  end
+
   ## other helpers ##
 
   def test_paginated_section