url data can be reinitialized

README.rdoc

@@ -46,7 +46,10 @@ In order to use the generated url attribute, you will probably want to override
 
 Routing called via named routes like <tt>foo_path(@foo)</tt> will automatically use the url. In your controllers you will need to call <tt>Foo.find_by_url(params[:id])</tt> instead of the regular find. Don't look for <tt>params[:url]</tt> unless you set it explicitly in the routing, <tt>to_param</tt> will generate <tt>params[:id]</tt>.
 
-Note that if you add <tt>acts_as_url</tt> to an existing model, the <tt>url</tt> database column will initially be blank. To set this column for your existing instances, you can use the <tt>initialize_urls</tt> method. So if your class is <tt>Post</tt>, just say <tt>Post.initialize_urls</tt>.
+Note that if you add <tt>acts_as_url</tt> to an existing model, the <tt>url</tt> database column will initially be blank. 
+To set this column for your existing instances, you can use the <tt>initialize_urls</tt> method. So if your class is <tt>Post</tt>, just say <tt>Post.initialize_urls</tt>.
+
+To update the existing <tt>url</tt> database column with data, you can use <tt>reinitialize_urls</tt> method. So if your class is <tt>Post</tt>, just say <tt>Post.reinitialize_urls</tt>.
 
 Unlike other permalink solutions, ActsAsUrl doesn't rely on Iconv (which is inconsistent across platforms and doesn't provide great transliteration as is) but instead uses a transliteration scheme (see the code for Unidecoder) which produces much better results for Unicode characters. It also mixes in some custom helpers to translate common characters into a more URI-friendly format rather than just dump them completely. Examples:
 

lib/stringex/acts_as_url.rb

@@ -96,6 +96,13 @@ def included(base = nil, &block)
       def initialize_urls
         acts_as_url_configuration.adapter.initialize_urls! self
       end
+
+      # Initialize the url fields for the records that need it. Designed for people who want to update
+      # <tt>acts_as_url</tt> support once there's already development/production data they'd
+      # like to keep around.
+      def reinitialize_urls
+        acts_as_url_configuration.adapter.reinitialize_urls! self
+      end
     end
 
     module ActsAsUrlInstanceMethods

lib/stringex/acts_as_url/adapter/base.rb

@@ -33,6 +33,12 @@ def initialize_urls!(klass)
           end
         end
 
+        def reinitialize_urls!(klass)
+          self.klass = klass
+          klass.update_all(settings.url_attribute => nil)
+          initialize_urls!(klass)
+        end
+
         def url_attribute(instance)
           # Retrieve from database record if there are errors on attribute_to_urlify
           if !is_new?(instance) && is_present?(instance.errors[settings.attribute_to_urlify])

test/unit/acts_as_url_integration_test.rb

@@ -224,6 +224,21 @@ def test_should_mass_initialize_urls
     assert_equal "subsequent", @other_doc.url
   end
 
+  def test_should_mass_reinitialize_urls
+    @doc = Document.create(title: "Initial")
+    @other_doc = Document.create(title: "Subsequent")
+    # Just making sure this got set before the reinitialize urls test
+    assert_equal "initial", @doc.url
+    assert_equal "subsequent", @other_doc.url
+
+    Document.reinitialize_urls
+
+    @doc.reload
+    @other_doc.reload
+    assert_equal "initial", @doc.url
+    assert_equal "subsequent", @other_doc.url
+  end
+
   def test_should_mass_initialize_urls_with_custom_url_attribute
     Document.class_eval do
       # Manually undefining the url method on Document which, in a real class not reused for tests,