Gracefully require

lib/jekyll.rb

@@ -18,75 +18,56 @@ require 'rubygems'
 # stdlib
 require 'fileutils'
 require 'time'
-require 'safe_yaml/load'
 require 'English'
 require 'pathname'
 require 'logger'
 
 # 3rd party
+require 'safe_yaml/load'
 require 'liquid'
 require 'kramdown'
 require 'colorator'
 
-# internal requires
-require 'jekyll/version'
-require 'jekyll/utils'
-require 'jekyll/log_adapter'
-require 'jekyll/stevenson'
-require 'jekyll/deprecator'
-require 'jekyll/configuration'
-require 'jekyll/document'
-require 'jekyll/collection'
-require 'jekyll/plugin_manager'
-require 'jekyll/frontmatter_defaults'
-require 'jekyll/site'
-require 'jekyll/convertible'
-require 'jekyll/url'
-require 'jekyll/layout'
-require 'jekyll/page'
-require 'jekyll/post'
-require 'jekyll/excerpt'
-require 'jekyll/draft'
-require 'jekyll/filters'
-require 'jekyll/static_file'
-require 'jekyll/errors'
-require 'jekyll/related_posts'
-require 'jekyll/cleaner'
-require 'jekyll/entry_filter'
-require 'jekyll/layout_reader'
-require 'jekyll/publisher'
-require 'jekyll/renderer'
-
-# extensions
-require 'jekyll/plugin'
-require 'jekyll/converter'
-require 'jekyll/generator'
-require 'jekyll/command'
-require 'jekyll/liquid_extensions'
-
-require_all 'jekyll/commands'
-require_all 'jekyll/converters'
-require_all 'jekyll/converters/markdown'
-require_all 'jekyll/generators'
-require_all 'jekyll/tags'
-
-# plugins
-require 'jekyll-coffeescript'
-require 'jekyll-sass-converter'
-
-# Eventually remove these for 3.0 as non-core
-require "classifier"
-require "pygments.rb"
-require "toml"
-require "jekyll-paginate"
-require "jekyll-gist"
-require "jekyll-coffeescript"
-require "jekyll-sass-converter"
-
 SafeYAML::OPTIONS[:suppress_warnings] = true
 
 module Jekyll
 
+  # internal requires
+  autoload :Cleaner,             'jekyll/cleaner'
+  autoload :Collection,          'jekyll/collection'
+  autoload :Configuration,       'jekyll/configuration'
+  autoload :Convertible,         'jekyll/convertible'
+  autoload :Deprecator,          'jekyll/deprecator'
+  autoload :Document,            'jekyll/document'
+  autoload :Draft,               'jekyll/draft'
+  autoload :EntryFilter,         'jekyll/entry_filter'
+  autoload :Errors,              'jekyll/errors'
+  autoload :Excerpt,             'jekyll/excerpt'
+  autoload :Filters,             'jekyll/filters'
+  autoload :FrontmatterDefaults, 'jekyll/frontmatter_defaults'
+  autoload :Layout,              'jekyll/layout'
+  autoload :LayoutReader,        'jekyll/layout_reader'
+  autoload :LogAdapter,          'jekyll/log_adapter'
+  autoload :Page,                'jekyll/page'
+  autoload :PluginManager,       'jekyll/plugin_manager'
+  autoload :Post,                'jekyll/post'
+  autoload :Publisher,           'jekyll/publisher'
+  autoload :RelatedPosts,        'jekyll/related_posts'
+  autoload :Renderer,            'jekyll/renderer'
+  autoload :Site,                'jekyll/site'
+  autoload :StaticFile,          'jekyll/static_file'
+  autoload :Stevenson,           'jekyll/stevenson'
+  autoload :URL,                 'jekyll/url'
+  autoload :Utils,               'jekyll/utils'
+  autoload :VERSION,             'jekyll/version'
+
+  # extensions
+  require 'jekyll/plugin'
+  require 'jekyll/converter'
+  require 'jekyll/generator'
+  require 'jekyll/command'
+  require 'jekyll/liquid_extensions'
+
   # Public: Tells you which Jekyll environment you are building in so you can skip tasks
   # if you need to.  This is useful when doing expensive compression tasks on css and
   # images and allows you to skip that when working in development.
@@ -149,3 +130,19 @@ module Jekyll
     end
   end
 end
+
+require_all 'jekyll/commands'
+require_all 'jekyll/converters'
+require_all 'jekyll/converters/markdown'
+require_all 'jekyll/generators'
+require_all 'jekyll/tags'
+
+# Eventually remove these for 3.0 as non-core
+Jekyll::Deprecator.gracefully_require(%w[
+  classifier
+  toml
+  jekyll-paginate
+  jekyll-gist
+  jekyll-coffeescript
+  jekyll-sass-converter
+])

lib/jekyll/commands/build.rb

@@ -58,7 +58,7 @@ module Jekyll
         #
         # Returns nothing.
         def watch(site, options)
-          require 'jekyll-watch'
+          Deprecator.gracefully_require 'jekyll-watch'
           Jekyll::Commands::Watch.watch(site, options)
         end
 

lib/jekyll/converters/markdown/rdiscount_parser.rb

@@ -3,13 +3,9 @@ module Jekyll
     class Markdown
       class RDiscountParser
         def initialize(config)
-          require 'rdiscount'
+          Jekyll::Deprecator.gracefully_require "rdiscount"
           @config = config
           @rdiscount_extensions = @config['rdiscount']['extensions'].map { |e| e.to_sym }
-        rescue LoadError
-          STDERR.puts 'You are missing a library required for Markdown. Please run:'
-          STDERR.puts '  $ [sudo] gem install rdiscount'
-          raise FatalException.new("Missing dependency: rdiscount")
         end
 
         def convert(content)

lib/jekyll/converters/markdown/redcarpet_parser.rb

@@ -14,7 +14,7 @@ module Jekyll
         module WithPygments
           include CommonMethods
           def block_code(code, lang)
-            require 'pygments'
+            Jekyll::Deprecator.gracefully_require("pygments")
             lang = lang && lang.split.first || "text"
             add_code_tags(
               Pygments.highlight(code, :lexer => lang, :options => { :encoding => 'utf-8' }),
@@ -55,45 +55,40 @@ module Jekyll
 
 
         def initialize(config)
-          require 'redcarpet'
+          Deprecator.gracefully_require("redcarpet")
           @config = config
           @redcarpet_extensions = {}
           @config['redcarpet']['extensions'].each { |e| @redcarpet_extensions[e.to_sym] = true }
 
-          @renderer ||= case @config['highlighter']
-                        when 'pygments'
-                          Class.new(Redcarpet::Render::HTML) do
-                            include WithPygments
-                          end
-                        when 'rouge'
-                          Class.new(Redcarpet::Render::HTML) do
-                            begin
-                              require 'rouge'
-                              require 'rouge/plugins/redcarpet'
-                            rescue LoadError => e
-                              Jekyll.logger.error "You are missing the 'rouge' gem. Please run:"
-                              Jekyll.logger.error " $ [sudo] gem install rouge"
-                              Jekyll.logger.error "Or add 'rouge' to your Gemfile."
-                              raise FatalException.new("Missing dependency: rouge")
-                            end
+          @renderer ||= class_with_proper_highlighter(@config['highlighter'])
+        end
 
-                            if Rouge.version < '1.3.0'
-                              abort "Please install Rouge 1.3.0 or greater and try running Jekyll again."
-                            end
+        def class_with_proper_highlighter(highlighter)
+          case highlighter
+          when "pygments"
+            Class.new(Redcarpet::Render::HTML) do
+              include WithPygments
+            end
+          when "rouge"
+            Class.new(Redcarpet::Render::HTML) do
+              Jekyll::Deprecator.gracefully_require(%w[
+                rouge
+                rouge/plugins/redcarpet
+              ])
 
-                            include Rouge::Plugins::Redcarpet
-                            include CommonMethods
-                            include WithRouge
-                          end
-                        else
-                          Class.new(Redcarpet::Render::HTML) do
-                            include WithoutHighlighting
-                          end
-                        end
-        rescue LoadError
-          STDERR.puts 'You are missing a library required for Markdown. Please run:'
-          STDERR.puts '  $ [sudo] gem install redcarpet'
-          raise FatalException.new("Missing dependency: redcarpet")
+              if Rouge.version < '1.3.0'
+                abort "Please install Rouge 1.3.0 or greater and try running Jekyll again."
+              end
+
+              include Rouge::Plugins::Redcarpet
+              include CommonMethods
+              include WithRouge
+            end
+          else
+            Class.new(Redcarpet::Render::HTML) do
+              include WithoutHighlighting
+            end
+          end
         end
 
         def convert(content)

lib/jekyll/deprecator.rb

@@ -1,5 +1,5 @@
 module Jekyll
-  class Deprecator
+  module Deprecator
     def self.process(args)
       no_subcommand(args)
       arg_is_present? args, "--server", "The --server command has been replaced by the \
@@ -32,5 +32,23 @@ module Jekyll
     def self.deprecation_message(message)
       Jekyll.logger.error "Deprecation:", message
     end
+
+    def self.gracefully_require(gem_name)
+      Array(gem_name).each do |name|
+        begin
+          require name
+        rescue LoadError => e
+          Jekyll.logger.error "Dependency Error:", <<-MSG
+  Yikes! It looks like you don't have #{name} or one of its dependencies installed.
+  In order to use Jekyll as currently contfigured, you'll need to install this gem.
+
+  The full error message from Ruby is: '#{e.message}'
+
+  If you run into trouble, you can find helpful resources at http://jekyllrb.com/help/!
+  MSG
+          raise Errors::MissingDependencyException.new(name)
+        end
+      end
+    end
   end
 end

lib/jekyll/errors.rb

@@ -1,4 +1,6 @@
 module Jekyll
   class FatalException < StandardError
+    class MissingDependencyException < FatalException
+    end
   end
 end