[Extensions] Manifests don't have to be hard. Allow discovery of basic assets and follow conventions for templates.

doc-src/content/tutorials/extensions.markdown

@@ -165,14 +165,26 @@ You may also see some real manifest files here:
 
 ### Manifest Declarations
 
-There are six kinds of manifest declarations:
+**Easy Mode:** If you just have some basic files and nothing fancy going on, simply place this line in your manifest:
+
+    discover :all
+
+This will cause compass to find all the files in your template and use the files' extension to determine where they should go. Alternatively, you can request that compass only discover files of a certain type. For example, the following will only discover javascript and image assets, you could then declare other file types on your own.
+
+    discover :javascripts
+    discover :images
+
+The following types may be discovered: `:stylesheets`, `:images`, `:javascripts`, `:fonts`, `:html`, `:files`, and `:directories`
+
+**Normal Mode:** There are seven kinds of manifest declarations:
 
 1. `stylesheet` - Declares a sass file.
 2. `image` - Declares an image.
 3. `javascript` - Declares a javascript file.
-4. `html` - Declares an html file.
-5. `file` - Declares a random file.
-6. `directory` - Declares a directory should be created.
+4. `font` - Declares a font file.
+5. `html` - Declares an html file.
+6. `file` - Declares a random file.
+7. `directory` - Declares a directory should be created.
 
 All declarations take the path to the file as their first argument. Note that the
 normal slash `/` can and should be used in a manifest. Compass will take care of

lib/compass/installers/manifest.rb

@@ -20,7 +20,19 @@ module Compass
         parse(manifest_file) if manifest_file
       end
 
-      def self.type(t)
+      def self.known_extensions
+        @known_extensions ||= {}
+      end
+
+      def self.plural_types
+        @plural_types ||= {}
+      end
+
+      def self.type(t, options = {})
+        Array(options[:extensions]).each do |ext|
+          self.known_extensions[ext] = t
+        end
+        self.plural_types[options[:plural]] = t if options[:plural]
         eval <<-END
           def #{t}(from, options = {})
              @entries << Entry.new(:#{t}, from, options)
@@ -34,13 +46,35 @@ module Compass
         END
       end
 
-      type :stylesheet
-      type :image
-      type :javascript
-      type :font
-      type :file
-      type :html
-      type :directory
+      type :stylesheet, :plural => :stylesheets, :extensions => %w(scss sass)
+      type :image,      :plural => :images,      :extensions => %w(png gif jpg jpeg tiff gif)
+      type :javascript, :plural => :javascripts, :extensions => %w(js)
+      type :font,       :plural => :fonts,       :extensions => %w(otf woff ttf)
+      type :html,       :plural => :html,        :extensions => %w(html haml)
+      type :file        :plural => :files
+      type :directory,  :plural => :directories
+
+      def discover(type)
+        type = self.class.plural_types[type] || type
+        dir = File.dirname(@manifest_file)
+        Dir.glob("#{dir}/**/*").each do |file|
+          next if /manifest\.rb/ =~ file
+          short_name = file[(dir.length+1)..-1]
+          options = {}
+          ext = if File.extname(short_name) == ".erb"
+            options[:erb] = true
+            File.extname(short_name[0..-5])
+          else
+            File.extname(short_name)
+          end[1..-1]
+          file_type = self.class.known_extensions[ext]
+          file_type = :file if file_type.nil?
+          file_type = :directory if File.directory?(file)
+          if type == :all || type == file_type
+            send(file_type, short_name, options)
+          end
+        end
+      end
 
       def help(value = nil)
         if value
@@ -96,13 +130,23 @@ module Compass
         @compile_after_generation = false
       end
 
+      def with_manifest(manifest_file)
+        @manifest_file = manifest_file
+        yield
+      ensure
+        @manifest_file = nil
+      end
+
       # parses a manifest file which is a ruby script
       # evaluated in a Manifest instance context
       def parse(manifest_file)
+        with_manifest(manifest_file) do
           open(manifest_file) do |f|
             eval(f.read, instance_binding, manifest_file)
           end
         end
+      end
+
       def instance_binding
         binding
       end