Eliminate all duplicate occurrences of the RDoc version that Hanna us…

…es, which

will make it very easy to change this version in the future.  Now, Hanna's RDoc
version can be changed simply by altering RDOC_VERSION in
lib/hanna/rdoc_version.rb.

bin/hanna

@@ -25,18 +25,14 @@ HELP
 end
 
 require 'rubygems'
-begin
-  gem 'rdoc', '~> 2.1.0'
-rescue Gem::LoadError
-  $stderr.puts "Hanna requires the RDoc 2.1 gem."
-  exit 1
-else
-  require 'rdoc/rdoc'
-end
 
 hanna_dir = File.expand_path(File.join(File.dirname(__FILE__), '..', 'lib'))
 $:.unshift(hanna_dir) unless $:.include?(hanna_dir)
 
+require 'hanna/rdoc_version'
+Hanna::require_rdoc
+require 'rdoc/rdoc'
+
 require 'hanna/rdoc_patch'
 
 options = []

hanna.gemspec

@@ -1,3 +1,8 @@
+#
+# This can be made cleaner by using the relative gem.
+#
+require File.join(File.dirname(__FILE__), "lib/hanna/rdoc_version")
+
 Gem::Specification.new do |s|
   s.name    = 'hanna'
   s.version = '0.1.3'
@@ -12,8 +17,8 @@ Gem::Specification.new do |s|
 
   s.executables = ['hanna']
   s.has_rdoc = false
-  s.add_dependency 'rdoc', ['~> 2.1.0']
+  s.add_dependency 'rdoc', [Hanna::RDOC_VERSION_REQUIREMENT]
   s.add_dependency 'haml', ['~> 2.0']
 
-  s.files = %w(README.markdown Rakefile bin bin/hanna lib lib/hanna lib/hanna.rb lib/hanna/hanna.rb lib/hanna/rdoc_patch.rb lib/hanna/rdoctask.rb lib/hanna/template_files lib/hanna/template_files/class_index.haml lib/hanna/template_files/file_index.haml lib/hanna/template_files/index.haml lib/hanna/template_files/layout.haml lib/hanna/template_files/method_list.haml lib/hanna/template_files/page.haml lib/hanna/template_files/sections.haml lib/hanna/template_files/styles.sass lib/hanna/template_helpers.rb lib/hanna/template_page_patch.rb)
+  s.files = %w(README.markdown Rakefile bin bin/hanna lib lib/hanna lib/hanna.rb lib/hanna/hanna.rb lib/hanna/rdoc_patch.rb lib/hanna/rdoc_version.rb lib/hanna/rdoctask.rb lib/hanna/template_files lib/hanna/template_files/class_index.haml lib/hanna/template_files/file_index.haml lib/hanna/template_files/index.haml lib/hanna/template_files/layout.haml lib/hanna/template_files/method_list.haml lib/hanna/template_files/page.haml lib/hanna/template_files/sections.haml lib/hanna/template_files/styles.sass lib/hanna/template_helpers.rb lib/hanna/template_page_patch.rb)
 end

lib/hanna/rdoc_version.rb

@@ -0,0 +1,21 @@
+module Hanna
+  #
+  # The version of RDoc that Hanna should use.
+  #
+  RDOC_VERSION = '2.1.0'
+  RDOC_VERSION_REQUIREMENT = "~> #{RDOC_VERSION}"
+
+  #
+  # This method loads the correct version of RDoc.  If the correct
+  # version of RDoc is not present, this method will terminate the
+  # program with a helpful error message.
+  #
+  def self.require_rdoc
+    begin
+      gem 'rdoc', RDOC_VERSION_REQUIREMENT
+    rescue Gem::LoadError
+      $stderr.puts "Error: hanna requires the RDoc #{RDOC_VERSION} gem!"
+      exit 1
+    end 
+  end
+end

lib/hanna/rdoctask.rb

@@ -1,3 +1,5 @@
+require 'hanna/rdoc_version'
+
 require 'rake'
 require 'rake/rdoctask'
 
@@ -31,12 +33,7 @@ def define
     task name => [rdoc_target]
     file rdoc_target => @rdoc_files + [$rakefile] do
       rm_r @rdoc_dir rescue nil
-
-      begin
-        gem 'rdoc', '~> 2.1.0'
-      rescue Gem::LoadError
-        $stderr.puts "Couldn't load RDoc 2.1 gem"
-      end
+      Hanna::require_rdoc
       require 'rdoc/rdoc'
       require 'hanna/rdoc_patch'