def register_transformer(from, to, proc)
      self.config = hash_reassoc(config, :registered_transformers) do |transformers|
        transformers << Transformer.new(from, to, proc)
      end
      compute_transformers!(self.config[:registered_transformers])
    end
def register_transformer(from, to, proc)
      self.config = hash_reassoc(config, :registered_transformers) do |transformers|
        transformers << Transformer.new(from, to, proc)
      end
      compute_transformers!(self.config[:registered_transformers])
    end
Public: Register a transformer from and to a mime type.

 from - String mime type
 to   - String mime type
 proc - Callable block that accepts an input Hash.

 Examples

   register_transformer 'text/coffeescript', 'application/javascript',
     ConvertCoffeeScriptToJavaScript

   register_transformer 'image/svg+xml', 'image/png', ConvertSvgToPng

 Returns nothing.