[Finishes sunspot#42] Adds :offset option to paginate method

sunspot/History.txt

@@ -10,6 +10,7 @@
 * Packaged Solr correctly uses the `pid_dir` configuration option from `sunspot.yml` (Russen Guggemos)
 * Specs run correctly in 1.9.2 (Larry Sprock)
 * Documentation improvements (Thibaut Barrère, gjb83, Breno Santos Salgado)
+* Adds :offset option to paginate method (Benjamin Fleischer)
 
 == 1.2.1 2010-12-28
 * Decreased default reindexing batch size from 500 to 50

sunspot/lib/sunspot/dsl/paginatable.rb

@@ -17,11 +17,15 @@ module Paginatable
       #   How many results to return per page. The default is the value in
       #   +Sunspot.config.pagination.default_per_page+
       #
+      # :offset<Integer,String>::
+      #   Applies a shift to paginated records. The default is 0.
+      #
       def paginate(options = {})
         page = options.delete(:page)
         per_page = options.delete(:per_page)
+        offset = options.delete(:offset)
         raise ArgumentError, "unknown argument #{options.keys.first.inspect} passed to paginate" unless options.empty?
-        @query.paginate(page, per_page)
+        @query.paginate(page, per_page, offset)
       end
     end
   end

sunspot/lib/sunspot/query/common_query.rb

@@ -35,12 +35,13 @@ def add_function(function)
         function
       end
 
-      def paginate(page, per_page)
+      def paginate(page, per_page, offset = nil)
         if @pagination
+          @pagination.offset = offset
           @pagination.page = page
           @pagination.per_page = per_page
         else
-          @components << @pagination = Pagination.new(page, per_page)
+          @components << @pagination = Pagination.new(page, per_page, offset)
         end
       end
 

sunspot/lib/sunspot/query/pagination.rb

@@ -6,10 +6,10 @@ module Query
     # reference to it and updates it if pagination is changed.
     #
     class Pagination #:nodoc:
-      attr_reader :page, :per_page
+      attr_reader :page, :per_page, :offset
 
-      def initialize(page = nil, per_page = nil)
-        self.page, self.per_page = page, per_page
+      def initialize(page = nil, per_page = nil, offset = nil)
+        self.offset, self.page, self.per_page = offset, page, per_page
       end
 
       def to_params
@@ -24,10 +24,14 @@ def per_page=(per_page)
         @per_page = per_page.to_i if per_page
       end
 
+      def offset=(offset)
+        @offset = offset.to_i
+      end
+
       private
 
       def start
-        (@page - 1) * @per_page
+        (@page - 1) * @per_page + @offset
       end
 
       def rows

sunspot/spec/api/query/ordering_pagination_examples.rb

@@ -25,6 +25,20 @@
     connection.should have_last_search_with(:rows => 15, :start => 0)
   end
 
+  it 'paginates with an offset' do
+    search do
+      paginate :per_page => 15, :offset => 3
+    end
+    connection.should have_last_search_with(:rows => 15, :start => 3)
+  end
+
+  it 'paginates with an offset as a string' do
+    search do
+      paginate :per_page => 15, :offset => '3'
+    end
+    connection.should have_last_search_with(:rows => 15, :start => 3)
+  end
+
   it 'paginates from string argument' do
     search do
       paginate :page => '3', :per_page => '15'

sunspot/spec/integration/test_pagination.rb

@@ -29,4 +29,15 @@
     end.results
     results.should == @posts[10,10]
   end
+
+  it 'should return pages with offsets' do
+    results = Sunspot.search(Post) do
+      order_by :blog_id
+      paginate :page => 2, :per_page => 5, :offset => 3
+    end.results
+
+    # page 1 is 3, 4, 5, 6, 7
+    # page 2 is 8, 9, 10, 11, 12
+    results.should == @posts[8,5]
+  end
 end