Proxy class for Array which adds pagination methods

sunspot/lib/sunspot/collection.rb

@@ -0,0 +1,52 @@
+module Sunspot
+  class Collection
+    instance_methods.each { |m| undef_method m unless m =~ /^__|instance_eval|object_id/ }
+
+    attr_reader :total_count, :current_page, :per_page
+    alias :total_entries :total_count
+    alias :limit_value :per_page
+
+    def initialize collection, page, total, per_page
+      @collection   = collection
+      @current_page = page
+      @per_page     = per_page
+      @total_count  = total
+    end
+
+    def total_pages
+      (total_count.to_f / per_page).ceil
+    end
+    alias :num_pages :total_pages
+
+    def first_page?
+      current_page == 1
+    end
+
+    def last_page?
+      current_page >= total_pages
+    end
+
+    def previous_page
+      current_page > 1 ? (current_page - 1) : nil
+    end
+
+    def next_page
+      current_page < total_pages ? (current_page + 1) : nil
+    end  
+
+    def out_of_bounds?
+      current_page > total_pages
+    end
+
+    def offset
+      (current_page - 1) * per_page
+    end
+
+    private
+
+    def method_missing(method, *args, &block)
+      @collection.send(method, *args, &block)
+    end
+
+  end
+end

sunspot/spec/api/collection_spec.rb

@@ -0,0 +1,27 @@
+require File.expand_path('spec_helper', File.dirname(__FILE__))
+require 'sunspot/collection'
+
+describe "Collection" do
+  subject { Sunspot::Collection.new [], 1, 20, 10 }
+
+  it { subject.should be_an(Array) }
+
+  context "behaves like a WillPaginate::Collection" do
+    it { subject.total_entries.should eql(20) }
+    it { subject.total_pages.should eql(2) }
+    it { subject.current_page.should eql(1) }
+    it { subject.per_page.should eql(10) }
+    it { subject.previous_page.should be_nil }
+    it { subject.next_page.should eql(2) }
+    it { subject.out_of_bounds?.should_not be_true }
+    it { subject.offset.should eql(0) }
+  end
+
+  context "behaves like Kaminari" do
+    it { subject.total_count.should eql(20) }
+    it { subject.num_pages.should eql(2) }
+    it { subject.limit_value.should eql(10) }
+    it { subject.first_page?.should be_true }
+    it { subject.last_page?.should_not be_true }
+  end
+end