Adds a FilenameCleaner class

You can either specifiy :restricted_characters or you can define your
own :filename_cleaner object. This object needs to respond to #call and
takes the filename that will be cleaned. It should return the cleaned
filenme.

lib/paperclip.rb

@@ -52,6 +52,7 @@ require 'paperclip/logger'
 require 'paperclip/helpers'
 require 'paperclip/has_attached_file'
 require 'paperclip/tasks/attachments'
+require 'paperclip/filename_cleaner'
 require 'mime/types'
 require 'logger'
 require 'cocaine'

lib/paperclip/attachment.rb

@@ -14,7 +14,7 @@ module Paperclip
         :default_url           => "/:attachment/:style/missing.png",
         :escape_url            => true,
         :restricted_characters => /[&$+,\/:;=?@<>\[\]\{\}\|\\\^~%# ]/,
-        :filename_sanitizer    => nil,
+        :filename_cleaner      => nil,
         :hash_data             => ":class/:attachment/:id/:style/:updated_at",
         :hash_digest           => "SHA1",
         :interpolator          => Paperclip::Interpolations,
@@ -99,12 +99,7 @@ module Paperclip
       return nil if file.nil?
 
       @queued_for_write[:original]   = file
-      cleaned_filename = if @options[:filename_sanitizer]
-        @options[:filename_sanitizer].call(file.original_filename, self)
-      else
-        cleanup_filename(file.original_filename)
-      end
-      instance_write(:file_name,       cleaned_filename)
+      instance_write(:file_name,       cleanup_filename(file.original_filename))
       instance_write(:content_type,    file.content_type.to_s.strip)
       instance_write(:file_size,       file.size)
       instance_write(:fingerprint,     file.fingerprint) if instance_respond_to?(:fingerprint)
@@ -366,14 +361,6 @@ module Paperclip
       end
     end
 
-    def cleanup_filename(filename)
-      if @options[:restricted_characters]
-        filename.gsub(@options[:restricted_characters], '_')
-      else
-        filename
-      end
-    end
-
     private
 
     def path_option
@@ -494,6 +481,14 @@ module Paperclip
        end
     end
 
+    def filename_cleaner
+      @options[:filename_cleaner] || FilenameCleaner.new(@options[:restricted_characters])
+    end
+
+    def cleanup_filename(filename)
+      filename_cleaner.call(filename)
+    end
+
     # Check if attachment database table has a created_at field
     def able_to_store_created_at?
       @instance.respond_to?("#{name}_created_at".to_sym)

lib/paperclip/filename_cleaner.rb

+# encoding: utf-8
+module Paperclip
+  class FilenameCleaner
+    def initialize(invalid_character_regex)
+      @invalid_character_regex = invalid_character_regex
+    end
+
+    def call(filename)
+      if @invalid_character_regex
+        filename.gsub(@invalid_character_regex, "_")
+      else
+        filename
+      end
+    end
+  end
+end

test/attachment_test.rb

@@ -917,7 +917,7 @@ class AttachmentTest < Test::Unit::TestCase
       end
     end
 
-    context 'with specified sanitizer proc' do
+    context 'with specified cleaner' do
       setup do
         @old_defaults = Paperclip::Attachment.default_options.dup
       end
@@ -926,11 +926,10 @@ class AttachmentTest < Test::Unit::TestCase
         Paperclip::Attachment.default_options.merge! @old_defaults
       end
 
-      should 'call proc and take it result as cleaned filename' do
-        proc = Proc.new do |str, attachment|
+      should 'call the given proc and take the result as cleaned filename' do
+        Paperclip::Attachment.default_options[:filename_cleaner] = lambda do |str|
           "from_proc_#{str}"
         end
-        Paperclip::Attachment.default_options[:filename_sanitizer] = proc
 
         @file.stubs(:original_filename).returns("goood.png")
         @dummy = Dummy.new
@@ -938,16 +937,18 @@ class AttachmentTest < Test::Unit::TestCase
         assert_equal "from_proc_goood.png", @dummy.avatar.original_filename
       end
 
-      should 'be able to call cleanup_filename from proc' do
-        proc = Proc.new do |str, attachment|
-          attachment.cleanup_filename "from_proc_#{str}"
+      should 'call the given object and take the result as the cleaned filename' do
+        class MyCleaner
+          def call(filename)
+            "foo"
+          end
         end
-        Paperclip::Attachment.default_options[:filename_sanitizer] = proc
+        Paperclip::Attachment.default_options[:filename_cleaner] = MyCleaner.new
 
-        @file.stubs(:original_filename).returns("go/ood.png")
+        @file.stubs(:original_filename).returns("goood.png")
         @dummy = Dummy.new
         @dummy.avatar = @file
-        assert_equal "from_proc_go_ood.png", @dummy.avatar.original_filename
+        assert_equal "foo", @dummy.avatar.original_filename
       end
     end
   end

test/filename_cleaner_test.rb

+# encoding: utf-8
+require './test/helper'
+
+class FilenameCleanerTest < Test::Unit::TestCase
+  should 'convert invalid characters to underscores' do
+    cleaner = Paperclip::FilenameCleaner.new(/[aeiou]/)
+    assert_equal "b_s_b_ll", cleaner.call("baseball")
+  end
+
+  should 'not convert anything if the character regex is nil' do
+    cleaner = Paperclip::FilenameCleaner.new(nil)
+    assert_equal "baseball", cleaner.call("baseball")
+  end
+end