module ActionController::ParamsWrapper

def process_action(*args)

by the metal call stack.
Performs parameters wrapping upon the request. Called automatically
def process_action(*args)
  if _wrapper_enabled?
    wrapped_hash = _wrap_parameters request.request_parameters
    wrapped_keys = request.request_parameters.keys
    wrapped_filtered_hash = _wrap_parameters request.filtered_parameters.slice(*wrapped_keys)
    # This will make the wrapped hash accessible from controller and view.
    request.parameters.merge! wrapped_hash
    request.request_parameters.merge! wrapped_hash
    # This will display the wrapped hash in the log file.
    request.filtered_parameters.merge! wrapped_filtered_hash
  end
  super
end