Add bidirectional front matter <-> header AsciiDoc mapping

This allows Awstruct to consume AsciiDoc's Headers as
Page variables and AsciiDoc to use Awestuct's Page variables
as Header values.

Gemfile

@@ -12,7 +12,7 @@ group :test do
   gem 'rack-test'
   gem 'tilt', '~> 1.3.4'
   gem 'coffee-script', '~> 2.2.0'
-  gem 'asciidoctor', '>= 0.1.0'
+  gem 'asciidoctor', '>= 0.1.1' # need 0.1.1 for Header support
   gem 'haml', '~> 4.0.0'
   gem 'slim', '~> 1.3.6'
   gem 'kramdown', '~> 0.14.2'

lib/awestruct/config/default-site.yml

@@ -7,5 +7,7 @@ content_syntax:
   ad: asciidoc
 
 asciidoctor:
-  attributes:
-    backend: html5
+  :backend: html5
+  :attributes:
+    imagesdir: '/images'
+    stylesdir: '/stylesheets'

lib/awestruct/handler_chains.rb

@@ -3,6 +3,7 @@
 require 'awestruct/handlers/css_tilt_handler'
 require 'awestruct/handlers/restructuredtext_handler'
 require 'awestruct/handlers/javascript_handler'
+require 'awestruct/handlers/asciidoctor_handler'
 require 'awestruct/handlers/redirect_handler'
 require 'awestruct/handlers/tilt_handler'
 
@@ -15,6 +16,7 @@ class HandlerChains
       Awestruct::Handlers::RedirectHandler::CHAIN,
       Awestruct::Handlers::RestructuredtextHandler::CHAIN,
       Awestruct::Handlers::JavascriptHandler::CHAIN,
+      Awestruct::Handlers::AsciidoctorHandler::CHAIN,
       Awestruct::Handlers::TiltHandler::NON_INTERPOLATION_CHAIN,
       Awestruct::Handlers::TiltHandler::INTERPOLATION_CHAIN,
       HandlerChain.new( /.*/, Awestruct::Handlers::FileHandler )

lib/awestruct/handlers/asciidoctor_handler.rb

@@ -0,0 +1,154 @@
+
+require 'awestruct/handler_chain'
+require 'awestruct/handlers/base_tilt_handler'
+require 'awestruct/handlers/file_handler'
+require 'awestruct/handlers/layout_handler'
+require 'awestruct/handlers/template/asciidoc'
+require 'yaml'
+
+require 'tilt'
+
+module Awestruct
+  module Handlers
+
+    class AsciidoctorMatcher
+      def match(path)
+        engine = Tilt[path]
+        engine == Tilt::AsciidoctorTemplate
+      end
+    end
+
+    class AsciidoctorHandler < BaseTiltHandler
+
+      CHAIN = Awestruct::HandlerChain.new( Awestruct::Handlers::AsciidoctorMatcher.new(),
+        Awestruct::Handlers::FileHandler,
+        Awestruct::Handlers::AsciidoctorHandler,
+        Awestruct::Handlers::LayoutHandler
+      )
+
+      def initialize(site, delegate)
+        super( site, delegate )
+
+        @front_matter = {}
+      end
+
+
+      def front_matter
+        parse_header()
+        @front_matter
+      end
+
+      def raw_content
+        parse_header()
+        super
+      end
+
+      def rendered_content(context, with_layouts)
+        parse_header()
+        types = [String, Numeric, TrueClass, FalseClass, Array]
+        @front_matter.merge!(context.page.inject({}) do |hash, (k,v)|
+          hash[k.to_s] = v if not k.to_s.start_with?("__") and types.detect { |t| v.kind_of? t}
+          hash
+        end)
+        super
+      end
+
+      def options
+        opts = super
+        if opts[:attributes].nil?
+          opts[:attributes] = @front_matter 
+        else
+          opts[:attributes] = opts[:attributes].merge @front_matter
+        end
+        opts[:attributes]["awestruct"] = true
+        opts[:attributes]["awestruct-version"] = Awestruct::VERSION
+        opts
+      end
+
+      def content_line_offset
+        parse_header()
+        @content_line_offset
+      end
+
+      def inherit_front_matter(page)
+        parse_header()
+        page.inherit_front_matter_from(@front_matter)
+      end
+
+      def parse_header
+        return if @parsed_parts
+
+        parse_front_matter
+        if content_line_offset == 0
+          content = delegate.raw_content
+          unless content.nil?
+            @front_matter = parse_document_attributes(content)
+            @parsed_parts = true
+          end
+        end
+      end
+
+      def parse_document_attributes(content)
+        template = Tilt::new(delegate.path.to_s, delegate.content_line_offset + 1, options)
+        template.parse_headers(content, /^awestruct\-/).inject({}) do |hash, (k,v)|
+          unless v.nil?
+            hash[k] = v.empty? ? v : YAML.load(v)
+          end
+          hash
+        end
+      end
+
+      def parse_front_matter
+        return if ( @parsed_parts && ! delegate.stale? )
+
+        full_content = delegate.raw_content
+        full_content.force_encoding(site.encoding) if site.encoding
+        yaml_content = ''
+
+        dash_lines = 0
+        mode = :yaml
+
+        @raw_content = ''
+        @content_line_offset = 0
+
+        full_content.each_line do |line|
+          if ( line.strip == '---' )
+            dash_lines = dash_lines +1
+          end
+          if ( mode == :yaml )
+            @content_line_offset += 1
+            yaml_content << line
+          else
+            @raw_content << line
+          end
+          if ( dash_lines == 2 )
+            mode = :page
+          end
+        end
+
+        if ( dash_lines == 0 )
+          @raw_content = yaml_content
+          yaml_content = ''
+          @content_line_offset = 0
+        elsif ( mode == :yaml )
+          @raw_content = nil
+          @content_line_offset = -1
+        end
+
+        begin
+          @front_matter = YAML.load( yaml_content ) || {}
+        rescue => e
+          puts "could not parse #{relative_source_path}"
+          raise e
+        end
+
+        @parsed_parts = true
+
+      end
+    end
+
+  end
+end
+
+require 'awestruct/handlers/template/asciidoc'
+Tilt::register Tilt::AsciidoctorTemplate, '.ad', '.adoc', '.asciidoc'

lib/awestruct/handlers/template/asciidoc.rb

@@ -23,5 +23,19 @@ def evaluate(scope, locals, &block)
     def allows_script?
       false
     end
+
+    def parse_headers(content, filter = /.*/)
+      doc = Asciidoctor.load(content, {:parse_header_only => true})
+      filtered = doc.attributes.select{|k,v| k =~ filter}.inject({}) do |hash, (k,v)|
+        hash[k.gsub(filter, '')] = v
+        hash
+      end
+
+      filtered["doctitle"] = doc.doctitle
+      filtered["date"] ||= doc.attributes["revdate"] unless doc.attributes["revdate"].nil?
+      filtered["author"] = doc.attributes["author"] unless doc.attributes["author"].nil?
+
+      filtered
+    end
   end
 end

lib/awestruct/handlers/tilt_handler.rb

@@ -61,9 +61,6 @@ def initialize(site, delegate)
 require 'awestruct/handlers/template/mustache'
 Tilt::register Tilt::MustacheTemplate, '.mustache'
 
-require 'awestruct/handlers/template/asciidoc'
-Tilt::register Tilt::AsciidoctorTemplate, '.ad', '.adoc', '.asciidoc'
-
 # As of Haml 4.0.0, Textile is no longer registered by default
 # Monkeypatch the Tilt templates to force Textile to be registered
 class Tilt::HamlTemplate
@@ -73,4 +70,4 @@ def initialize_engine
       Haml::Filters.register_tilt_filter 'Textile'
     end
   end
-end
+end

spec/asciidoc_handler_spec.rb

@@ -1,4 +1,5 @@
 require 'spec_helper'
+require 'rspec/matchers.rb'
 
 verify = lambda { |output|
   output.gsub(/(^\s*\n|^\s*)/, '').should =~ %r(<div id="preamble">
@@ -10,6 +11,21 @@
 </div>)
 }
 
+verify_front_matter = lambda { |output, page|
+  page.title.should == 'AwestructAsciiDoc'
+}
+
+verify_headers = lambda { |output, page|
+  extend RSpec::Matchers
+
+  page.name.should == 'Awestruct'
+  page.tags.should be_a_kind_of(Array)
+  page.tags.should == %w(a b c)
+  page.date.should be_a_kind_of(Date)
+  output.should =~ %r(This is <strong>AsciiDoc</strong> in Awestruct.)
+  output.should =~ %r(#{Awestruct::VERSION})
+}
+
 theories =
   [
     {
@@ -32,11 +48,25 @@
       :syntax => :asciidoc,
       :extension => '.html',
       :matcher => verify
+    },
+    {
+      :page => "asciidoctor_with_front_matter.ad",
+      :simple_name => "asciidoctor_with_front_matter",
+      :syntax => :asciidoc,
+      :extension => '.html' ,
+      :matcher => verify_front_matter
+    },
+    {
+      :page => "asciidoctor_with_headers.ad",
+      :simple_name => "asciidoctor_with_headers",
+      :syntax => :asciidoc,
+      :extension => '.html',
+      :matcher => verify_headers
     }
   ]
 
-describe Awestruct::Handlers::TiltHandler.to_s + "-AsciiDoc" do
-
+describe Awestruct::Handlers::AsciidoctorHandler do
+  let(:additional_config_page) { {:name => 'Awestruct', :test => 10} }
   it_should_behave_like "a handler", theories
 
 end

spec/engine_spec.rb

@@ -11,7 +11,7 @@
     engine = Awestruct::Engine.new(config)
     engine.load_default_site_yaml
 
-    engine.site.asciidoctor.attributes.backend.should == 'html5'
+    engine.site.asciidoctor.backend.should == 'html5'
   end
 
   it "should be able to override default with site" do

spec/support/shared_handler_example.rb

@@ -67,10 +67,13 @@ def create_handler(page)
         it "should render page '#{theory[:page]}'" do
           if theory[:unless].nil? or !theory[:unless][:exp].call()
             handler = create_handler theory[:page]
-            output = handler.rendered_content( create_context )
+            handler.merge! additional_config_page if respond_to?("additional_config_page")
+
+            output = handler.rendered_content( handler.create_context )
             output.should_not be_nil
 
-            theory[:matcher].call(output)
+            theory[:matcher].call(output, handler) if theory[:matcher].arity == 2
+            theory[:matcher].call(output) if theory[:matcher].arity == 1
           else
             pending theory[:unless][:message]
           end

spec/test-data/handlers/asciidoctor_with_front_matter.ad

@@ -0,0 +1,6 @@
+---
+title: AwestructAsciiDoc
+---
+= AsciiDoc
+
+This is *AsciiDoc* in Awestruct.

spec/test-data/handlers/asciidoctor_with_headers.ad

@@ -0,0 +1,8 @@
+= AsciiDoc
+Stuart Rackham
+2013-02-06
+:awestruct-tags: [a, b, c]
+:name: NOT_HANDLED
+
+This is *AsciiDoc* in {name}.
+{awestruct-version}