Adds support for S3 scheme-less URL generation

lib/paperclip/storage/s3.rb

@@ -39,8 +39,9 @@ module Storage
     #     :s3_permissions => :private
     #
     # * +s3_protocol+: The protocol for the URLs generated to your S3 assets. Can be either
-    #   'http' or 'https'. Defaults to 'http' when your :s3_permissions are :public_read (the
-    #   default), and 'https' when your :s3_permissions are anything else.
+    #   'http', 'https', or an empty string to generate scheme-less URLs. Defaults to 'http'
+    #   when your :s3_permissions are :public_read (the default), and 'https' when your
+    #   :s3_permissions are anything else.
     # * +s3_headers+: A hash of headers or a Proc. You may specify a hash such as
     #   {'Expires' => 1.year.from_now.httpdate}. If you use a Proc, headers are determined at
     #   runtime. Paperclip will call that Proc with attachment as the only argument.
@@ -125,14 +126,18 @@ def self.extended base
 
           @http_proxy = @options[:http_proxy] || nil
         end
+
         Paperclip.interpolates(:s3_alias_url) do |attachment, style|
-          "#{attachment.s3_protocol(style)}://#{attachment.s3_host_alias}/#{attachment.path(style).gsub(%r{^/}, "")}"
+          url_prefix = (s3_protocol = attachment.s3_protocol(style)).present? ? "#{s3_protocol}:" : ""
+          "#{url_prefix}//#{attachment.s3_host_alias}/#{attachment.path(style).gsub(%r{^/}, "")}"
         end unless Paperclip::Interpolations.respond_to? :s3_alias_url
         Paperclip.interpolates(:s3_path_url) do |attachment, style|
-          "#{attachment.s3_protocol(style)}://#{attachment.s3_host_name}/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
+          url_prefix = (s3_protocol = attachment.s3_protocol(style)).present? ? "#{s3_protocol}:" : ""
+          "#{url_prefix}//#{attachment.s3_host_name}/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
         end unless Paperclip::Interpolations.respond_to? :s3_path_url
         Paperclip.interpolates(:s3_domain_url) do |attachment, style|
-          "#{attachment.s3_protocol(style)}://#{attachment.bucket_name}.#{attachment.s3_host_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
+          url_prefix = (s3_protocol = attachment.s3_protocol(style)).present? ? "#{s3_protocol}:" : ""
+          "#{url_prefix}//#{attachment.bucket_name}.#{attachment.s3_host_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
         end unless Paperclip::Interpolations.respond_to? :s3_domain_url
         Paperclip.interpolates(:asset_host) do |attachment, style|
           "#{attachment.path(style).gsub(%r{^/}, "")}"

test/storage/s3_test.rb

@@ -129,6 +129,38 @@ def teardown
 
   end
 
+  context ":s3_protocol => 'https'" do
+    setup do
+      rebuild_model :storage => :s3,
+                    :s3_credentials => {},
+                    :s3_protocol => 'https',
+                    :bucket => "bucket",
+                    :path => ":attachment/:basename.:extension"
+      @dummy = Dummy.new
+      @dummy.avatar = StringIO.new(".")
+    end
+
+    should "return a url based on an S3 path" do
+      assert_match %r{^https://s3.amazonaws.com/bucket/avatars/stringio.txt}, @dummy.avatar.url
+    end
+  end
+
+  context ":s3_protocol => ''" do
+    setup do
+      rebuild_model :storage => :s3,
+                    :s3_credentials => {},
+                    :s3_protocol => '',
+                    :bucket => "bucket",
+                    :path => ":attachment/:basename.:extension"
+      @dummy = Dummy.new
+      @dummy.avatar = StringIO.new(".")
+    end
+
+    should "return a url based on an S3 path" do
+      assert_match %r{^//s3.amazonaws.com/bucket/avatars/stringio.txt}, @dummy.avatar.url
+    end
+  end
+
   context "An attachment that uses S3 for storage and has the style in the path" do
     setup do
       rebuild_model :storage => :s3,