module ActionController::ParameterEncoding::ClassMethods

def binary_params_for?(action) # :nodoc:

:nodoc: 
def binary_params_for?(action) # :nodoc:
  @_parameter_encodings[action.to_s]
end

def inherited(klass) # :nodoc:

:nodoc: 
def inherited(klass) # :nodoc:
  super
  klass.setup_param_encode
end

def setup_param_encode # :nodoc:

:nodoc: 
def setup_param_encode # :nodoc:
  @_parameter_encodings = {}
end

def skip_parameter_encoding(action)

must handle data but encoding of the data is unknown, like file system data.
encoded as ASCII-8BIT. This is useful in the case where an application
The show action in the above controller would have all parameter values

end
end
@repositories = Repository.all
def index

end
@repo_name = params[:repo_name].force_encoding 'UTF-8'
# tag it as such
# `repo_name` is guaranteed to be UTF-8, but was ASCII-8BIT, so

@repo = Repository.find_by_filesystem_path params[:file_path]
def show

skip_parameter_encoding :show
class RepositoryController < ActionController::Base

For example, a controller would use it like this:

ASCII-8BIT (it "skips" the encoding default of UTF-8).
Specify that a given action's parameters should all be encoded as 
def skip_parameter_encoding(action)
  @_parameter_encodings[action.to_s] = true
end