Extract dependency tracking from Digestor

2 files changed, 73 insertions, 44 deletions

diff --git a/actionpack/lib/action_view/dependency_tracker.rb b/actionpack/lib/action_view/dependency_tracker.rb
new file mode 100644
index 0000000000..1e31185c26
--- /dev/null
+++ b/actionpack/lib/action_view/dependency_tracker.rb
@@ -0,0 +1,66 @@
+module ActionView
+  class DependencyTracker
+    def self.find_dependencies(name, template)
+      ErbTracker.call(name, template)
+    end
+
+    class ErbTracker
+      EXPLICIT_DEPENDENCY = /# Template Dependency: (\S+)/
+
+      # Matches:
+      #   render partial: "comments/comment", collection: commentable.comments
+      #   render "comments/comments"
+      #   render 'comments/comments'
+      #   render('comments/comments')
+      #
+      #   render(@topic)         => render("topics/topic")
+      #   render(topics)         => render("topics/topic")
+      #   render(message.topics) => render("topics/topic")
+      RENDER_DEPENDENCY = /
+        render\s*                     # render, followed by optional whitespace
+        \(?                           # start an optional parenthesis for the render call
+        (partial:|:partial\s+=>)?\s*  # naming the partial, used with collection -- 1st capture
+        ([@a-z"'][@a-z_\/\."']+)      # the template name itself -- 2nd capture
+      /x
+
+      def self.call(name, template)
+        new(name, template).call
+      end
+
+      def initialize(name, template)
+        @name, @template = name, template
+      end
+
+      def call
+        render_dependencies + explicit_dependencies
+      end
+
+      private
+        attr_reader :name, :template
+
+        def directory
+          name.split("/")[0..-2].join("/")
+        end
+
+        def render_dependencies
+          template.source.scan(RENDER_DEPENDENCY).
+            collect(&:second).uniq.
+
+            # render(@topic)         => render("topics/topic")
+            # render(topics)         => render("topics/topic")
+            # render(message.topics) => render("topics/topic")
+            collect { |name| name.sub(/\A@?([a-z]+\.)*([a-z_]+)\z/) { "#{$2.pluralize}/#{$2.singularize}" } }.
+
+            # render("headline") => render("message/headline")
+            collect { |name| name.include?("/") ? name : "#{directory}/#{name}" }.
+
+            # replace quotes from string renders
+            collect { |name| name.gsub(/["']/, "") }
+        end
+
+        def explicit_dependencies
+          template.source.scan(EXPLICIT_DEPENDENCY).flatten.uniq
+        end
+    end
+  end
+end
diff --git a/actionpack/lib/action_view/digestor.rb b/actionpack/lib/action_view/digestor.rb
index 4507861dcc..9324a1ac50 100644
--- a/actionpack/lib/action_view/digestor.rb
+++ b/actionpack/lib/action_view/digestor.rb
@@ -1,25 +1,8 @@
 require 'thread_safe'
+require 'action_view/dependency_tracker'
 
 module ActionView
   class Digestor
-    EXPLICIT_DEPENDENCY = /# Template Dependency: (\S+)/
-
-    # Matches:
-    #   render partial: "comments/comment", collection: commentable.comments
-    #   render "comments/comments"
-    #   render 'comments/comments'
-    #   render('comments/comments')
-    #
-    #   render(@topic)         => render("topics/topic")
-    #   render(topics)         => render("topics/topic")
-    #   render(message.topics) => render("topics/topic")
-    RENDER_DEPENDENCY = /
-      render\s*                     # render, followed by optional whitespace
-      \(?                           # start an optional parenthesis for the render call
-      (partial:|:partial\s+=>)?\s*  # naming the partial, used with collection -- 1st capture
-      ([@a-z"'][@a-z_\/\."']+)      # the template name itself -- 2nd capture
-    /x
-
     cattr_reader(:cache)
     @@cache = ThreadSafe::Cache.new
 
@@ -47,7 +30,7 @@ module ActionView
     end
 
     def dependencies
-      render_dependencies + explicit_dependencies
+      DependencyTracker.find_dependencies(name, template)
     rescue ActionView::MissingTemplate
       [] # File doesn't exist, so no dependencies
     end
@@ -69,16 +52,16 @@ module ActionView
         name.gsub(%r|/_|, "/")
       end
 
-      def directory
-        name.split("/")[0..-2].join("/")
-      end
-
       def partial?
         false
       end
 
+      def template
+        @template ||= finder.find(logical_name, [], partial?, formats: [ format ])
+      end
+
       def source
-        @source ||= finder.find(logical_name, [], partial?, formats: [ format ]).source
+        template.source
       end
 
       def dependency_digest
@@ -89,26 +72,6 @@ module ActionView
         (template_digests + injected_dependencies).join("-")
       end
 
-      def render_dependencies
-        source.scan(RENDER_DEPENDENCY).
-          collect(&:second).uniq.
-
-          # render(@topic)         => render("topics/topic")
-          # render(topics)         => render("topics/topic")
-          # render(message.topics) => render("topics/topic")
-          collect { |name| name.sub(/\A@?([a-z]+\.)*([a-z_]+)\z/) { "#{$2.pluralize}/#{$2.singularize}" } }.
-
-          # render("headline") => render("message/headline")
-          collect { |name| name.include?("/") ? name : "#{directory}/#{name}" }.
-
-          # replace quotes from string renders
-          collect { |name| name.gsub(/["']/, "") }
-      end
-
-      def explicit_dependencies
-        source.scan(EXPLICIT_DEPENDENCY).flatten.uniq
-      end
-
       def injected_dependencies
         Array.wrap(options[:dependencies])
       end