From fed95f9c5e70d4b7df04008d9f394436f8b26d1f Mon Sep 17 00:00:00 2001
From: Ben Hollis <ben@benhollis.net>
Date: Sun, 25 May 2014 18:43:49 -0700
Subject: [PATCH] Convert external data to a real extension

---
 .../lib/middleman-core/application.rb         |  4 +-
 .../lib/middleman-core/core_extensions.rb     |  5 +-
 .../middleman-core/core_extensions/data.rb    | 74 ++++++++-----------
 3 files changed, 36 insertions(+), 47 deletions(-)

diff --git a/middleman-core/lib/middleman-core/application.rb b/middleman-core/lib/middleman-core/application.rb
index c3ea9b89..94e8c23f 100644
--- a/middleman-core/lib/middleman-core/application.rb
+++ b/middleman-core/lib/middleman-core/application.rb
@@ -142,9 +142,6 @@ module Middleman
     # Handle exceptions
     include Middleman::CoreExtensions::ShowExceptions
 
-    # Activate Data package
-    include Middleman::CoreExtensions::Data
-
     # Setup custom rendering
     include Middleman::CoreExtensions::Rendering
 
@@ -188,6 +185,7 @@ module Middleman
       # Parse YAML from templates. Must be before sitemap so sitemap
       # extensions see updated frontmatter!
       activate :front_matter
+      activate :data
       activate :file_watcher
 
       # Initialize the Sitemap
diff --git a/middleman-core/lib/middleman-core/core_extensions.rb b/middleman-core/lib/middleman-core/core_extensions.rb
index 237893eb..64be17ef 100644
--- a/middleman-core/lib/middleman-core/core_extensions.rb
+++ b/middleman-core/lib/middleman-core/core_extensions.rb
@@ -6,7 +6,10 @@ end
 
 # Data looks at the data/ folder for YAML files and makes them available
 # to dynamic requests.
-require 'middleman-core/core_extensions/data'
+Middleman::Extensions.register :data do
+  require 'middleman-core/core_extensions/data'
+  Middleman::CoreExtensions::Data
+end
 
 # Parse YAML from templates
 Middleman::Extensions.register :front_matter do
diff --git a/middleman-core/lib/middleman-core/core_extensions/data.rb b/middleman-core/lib/middleman-core/core_extensions/data.rb
index df332f42..8fac7911 100644
--- a/middleman-core/lib/middleman-core/core_extensions/data.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/data.rb
@@ -1,37 +1,35 @@
+require 'yaml'
+require 'active_support/json'
+
 module Middleman
   module CoreExtensions
-    # The data extension parses YAML and JSON files in the data/ directory
-    # and makes them available to config.rb, templates and extensions
-    module Data
-      # Extension registered
-      class << self
-        # @private
-        def included(app)
-          # Data formats
-          require 'yaml'
-          require 'active_support/json'
+    # The data extension parses YAML and JSON files in the `data/` directory
+    # and makes them available to `config.rb`, templates and extensions
+    class Data < Extension
+      # The regex which tells Middleman which files are for data
+      MATCHER = /[\w-]+\.(yml|yaml|json)$/
 
-          app.config.define_setting :data_dir, 'data', 'The directory data files are stored in'
-          app.send :include, InstanceMethods
+      def initialize(app, options_hash={}, &block)
+        super
+        app.config.define_setting :data_dir, 'data', 'The directory data files are stored in'
+
+        # Directly include the #data method instead of using helpers so that this is available immediately
+        app.send :include, InstanceMethods
+      end
+
+      def before_configuration
+        # Setup data files before anything else so they are available when
+        # parsing config.rb
+        app.files.changed MATCHER do |file|
+          data.touch_file(file) if file.start_with?("#{config[:data_dir]}/")
+        end
+
+        app.files.deleted MATCHER do |file|
+          data.remove_file(file) if file.start_with?("#{config[:data_dir]}/")
         end
       end
 
-      # Instance methods
       module InstanceMethods
-        # Setup data files before anything else so they are available when
-        # parsing config.rb
-        def initialize
-          files.changed DataStore.matcher do |file|
-            data.touch_file(file) if file.start_with?("#{config[:data_dir]}/")
-          end
-
-          files.deleted DataStore.matcher do |file|
-            data.remove_file(file) if file.start_with?("#{config[:data_dir]}/")
-          end
-
-          super
-        end
-
         # The data object
         #
         # @return [DataStore]
@@ -42,25 +40,14 @@ module Middleman
 
       # The core logic behind the data extension.
       class DataStore
-        # Static methods
-        class << self
-          # The regex which tells Middleman which files are for data
-          #
-          # @return [Regexp]
-          def matcher
-            %r{[\w-]+\.(yml|yaml|json)$}
-          end
-        end
-
         # Store static data hash
         #
         # @param [Symbol] name Name of the data, used for namespacing
         # @param [Hash] content The content for this data
         # @return [Hash]
         def store(name=nil, content=nil)
-          @_local_sources ||= {}
-          @_local_sources[name.to_s] = content unless name.nil? || content.nil?
-          @_local_sources
+          @local_sources[name.to_s] = content unless name.nil? || content.nil?
+          @local_sources
         end
 
         # Store callback-based data
@@ -69,9 +56,8 @@ module Middleman
         # @param [Proc] proc The callback which will return data
         # @return [Hash]
         def callbacks(name=nil, proc=nil)
-          @_callback_sources ||= {}
-          @_callback_sources[name.to_s] = proc unless name.nil? || proc.nil?
-          @_callback_sources
+          @callback_sources[name.to_s] = proc unless name.nil? || proc.nil?
+          @callback_sources
         end
 
         # Setup data store
@@ -80,6 +66,8 @@ module Middleman
         def initialize(app)
           @app = app
           @local_data = {}
+          @local_sources = {}
+          @callback_sources = {}
         end
 
         # Update the internal cache for a given file path