Adding new extension hooks

There are three new extension hooks in place now:

* before_extensions
+
All extensions added via this method, following the same extension rules, will be
run before any other extensions loaded with `extension`.
* after_extensions
+
All extensions added via this method, following the same extension rules, will be
run after any other extensions loaded with `extension`.
* after_generation
+
All extensions added via this method, following the same extension rules, will be
run after the page generation is completed. This will only run on the
first generation, not on reloads.

Extensions will now be notified if they are being reloaded. To be
notified of this an extension must have an `on_reload(site)` method,
which will be called if there is a change. An extension is then free to
re-run an initialization logic, clean-up the site variable, or create
new state needed for a re-run of the `execute(site)` method.

lib/awestruct/engine.rb

@@ -69,7 +69,7 @@ def run(profile, base_url, default_base_url, force=false, generate=true)
       load_pages
       $LOG.debug 'execute_pipeline' if $LOG.debug?
       $LOG.info 'Excecuting pipeline...' if $LOG.info?
-      execute_pipeline
+      execute_pipeline(false)
       $LOG.debug 'configure_compass' if $LOG.debug?
       configure_compass
       $LOG.debug 'set_urls' if $LOG.debug?
@@ -246,22 +246,31 @@ def load_pipeline
       pipeline_file = File.join( ext_dir, 'pipeline.rb' )
       if ( File.exists?( pipeline_file ) )
         p = eval(File.read( pipeline_file ), nil, pipeline_file, 1)
+        p.before_pipeline_extensions.each do |e|
+          pipeline.before_pipeline_extension( e )
+        end
         p.extensions.each do |e|
           pipeline.extension( e )
         end
+        p.after_pipeline_extensions.each do |e|
+          pipeline.after_pipeline_extension( e )
+        end
         p.helpers.each do |h|
           pipeline.helper( h )
         end
         p.transformers.each do |t|
           pipeline.transformer( t )
         end
+        p.after_generation_extensions.each do |e|
+          pipeline.after_generation_extension( e )
+        end
       end
     end
 
-    def execute_pipeline
+    def execute_pipeline(on_reload = false)
       FileUtils.mkdir_p( site.config.output_dir )
       FileUtils.mkdir_p( site.config.tmp_dir )
-      pipeline.execute( site )
+      pipeline.execute( site, on_reload )
     end
 
     def configure_compass 
@@ -356,6 +365,7 @@ def generate_output
           generate_page( page, generated_path, false )
         end
       end
+      site.engine.pipeline.execute_after_generation(site)
     end
 
     def generate_page(page, generated_path, produce_output=true)
@@ -438,7 +448,7 @@ def run_auto_for_non_page(file, generate = true)
       @pipeline = Pipeline.new
       load_yamls
       load_pipeline
-      execute_pipeline
+      execute_pipeline(true)
 
       if ( generate )
         site.pages.each do |p|

lib/awestruct/extensions/pipeline.rb

@@ -11,31 +11,45 @@
 
 module Awestruct
   module Extensions
+    # Public. Extension declaration class, initialized by the end user to
+    # declare their extensions, helpers, transformers, etc.
     class Pipeline
 
-      attr_reader :before_extensions
+      attr_reader :before_pipeline_extensions
       attr_reader :extensions
-      attr_reader :after_extensions
+      attr_reader :after_pipeline_extensions
       attr_reader :helpers
       attr_reader :transformers
+      attr_reader :after_generation_extensions
 
       def initialize(&block)
-        @extensions   = []
-        @helpers      = []
-        @transformers = []
+        @before_pipeline_extensions  = []
+        @extensions                  = []
+        @helpers                     = []
+        @transformers                = []
+        @after_pipeline_extensions   = []
+        @after_generation_extensions = []
         begin
-          instance_eval &block if block
+          instance_eval(&block) if block
         rescue Exception => e
           abort("Failed to initialize pipeline: #{e}")
         end
       end
 
+      def before_extensions(ext)
+        @before_pipeline_extensions << ext
+      end
+
       def extension(ext)
         @extensions << ext
         # TC: why? transformer and extension?
         ext.transform(@transformers) if ext.respond_to?('transform')
       end
 
+      def after_extensions(ext)
+        @after_pipeline_extensions << ext
+      end
+
       def helper(helper)
         @helpers << helper
       end
@@ -44,6 +58,10 @@ def transformer(transformer)
         @transformers << transformer
       end
 
+      def after_generation(ext)
+        @after_generation_extensions << ext
+      end
+
       def execute(site)
         extensions.each do |ext|
           ext.execute( site )

lib/awestruct/pipeline.rb

@@ -6,12 +6,25 @@ module Awestruct
   class Pipeline
 
     attr_reader :handler_chains
+    attr_reader :before_pipeline_extensions
+    attr_reader :extensions
+    attr_reader :after_pipeline_extensions
+    attr_reader :helpers
+    attr_reader :transformers
+    attr_reader :after_generation_extensions
 
     def initialize()
       @handler_chains = HandlerChains.new
-      @extensions     = []
-      @helpers        = []
-      @transformers   = []
+      @before_pipeline_extensions  = []
+      @extensions                  = []
+      @helpers                     = []
+      @transformers                = []
+      @after_pipeline_extensions   = []
+      @after_generation_extensions = []
+    end
+
+    def before_pipeline_extension(e)
+      @before_pipeline_extensions << e
     end
 
     def extension(e)
@@ -20,6 +33,10 @@ def extension(e)
       e.transform(@transformers) if e.respond_to?('transform')
     end
 
+    def after_pipeline_extension(e)
+      @after_pipeline_extensions << e
+    end
+
     def helper(h)
       @helpers << h
     end
@@ -28,12 +45,27 @@ def transformer(t)
       @transformers << t
     end
 
-    def execute(site)
-      execute_extensions(site)
+    def after_generation_extension(e)
+      @after_generation_extensions << e
     end
 
-    def execute_extensions(site)
+    def execute(site, on_reload = false)
+      execute_extensions(site, on_reload)
+    end
+
+    def execute_extensions(site, on_reload)
+      @before_pipeline_extensions.each do |e|
+        e.on_reload(site) if (on_reload && e.respond_to?(:on_reload))
+        e.execute(site)
+      end
+
       @extensions.each do |e|
+        e.on_reload(site) if (on_reload && e.respond_to?(:on_reload))
+        e.execute(site)
+      end
+
+      @after_pipeline_extensions.each do |e|
+        e.on_reload(site) if (on_reload && e.respond_to?(:on_reload))
         e.execute(site)
       end
     end
@@ -45,6 +77,12 @@ def apply_transformers(site, page, rendered)
       rendered
     end
 
+    def execute_after_generation(site)
+      @after_generation_extensions.each do |e|
+        e.execute(site)
+      end
+    end
+
     def mixin_helpers(context)
       context.extend( Awestruct::ContextHelper )
       @helpers.each do |h|

spec/awestruct/pipeline_spec.rb

@@ -1,15 +1,32 @@
-
-require 'awestruct/pipeline'
-
+require 'awestruct/engine'
+require 'awestruct/pipeline' 
 
 describe Awestruct::Pipeline do
-  before do
-    dir = Pathname.new( test_data_dir 'engine' )
+  before do 
+    dir = Pathname.new( test_data_dir 'pipeline' )
     opts = Awestruct::CLI::Options.new
     opts.source_dir = dir
 
-    @site = Hashery::OpenCascade[ { :encoding=>false, :dir=>dir, :config=>Awestruct::Config.new( opts ) } ]
-    Awestruct::Engine.new(@site.config)
+    @site = Hashery::OpenCascade[ { :encoding=>false, :dir=>dir, :config=>Awestruct::Config.new( opts ), :pages => [] } ]
+    @engine = Awestruct::Engine.new(@site.config)
+
+    log = StringIO.new
+    $LOG = Logger.new(log)
+    $LOG.level = Logger::DEBUG 
+
+    @engine.load_pipeline
+    @pipeline = @engine.pipeline
+  end
+
+  context "after pipeline is loaded" do 
+    specify "should have all specified extension points" do
+      expect(@pipeline.before_pipeline_extensions.size).to eql 1
+      expect(@pipeline.extensions.size).to eql 1
+      expect(@pipeline.after_pipeline_extensions.size).to eql 1
+      expect(@pipeline.helpers.size).to eql 1
+      expect(@pipeline.transformers.size).to eql 1
+      expect(@pipeline.after_generation_extensions.size).to eql 1
+    end
   end
 
   it "should provide a way to find a matching handler chain for a given path" do

spec/support/test-data/pipeline/_ext/extensions.rb

@@ -0,0 +1,26 @@
+module Awestruct
+  module Test
+    module Extensions
+      class TestBeforeExtension
+        def execute site
+        end
+      end
+
+      class TestAfterExtension
+        def execute site
+        end
+      end
+
+      class TestAfterGenerationExtension
+        def execute site
+        end
+      end
+
+      class LinkTransformer
+        def transform site, page, content
+        end
+      end
+    end
+  end
+end
+

spec/support/test-data/pipeline/_ext/pipeline.rb

@@ -0,0 +1,11 @@
+require 'support/test-data/pipeline/_ext/extensions'
+
+Awestruct::Extensions::Pipeline.new do
+  before_extensions Awestruct::Test::Extensions::TestBeforeExtension.new
+  extension Awestruct::Extensions::Indexifier.new
+  after_extensions Awestruct::Test::Extensions::TestAfterExtension.new
+  helper Awestruct::Extensions::Relative
+  transformer Awestruct::Test::Extensions::LinkTransformer.new
+  after_generation Awestruct::Test::Extensions::TestAfterGenerationExtension.new
+end
+