module ActionController::ParameterEncoding::ClassMethods

but encoding of the data is unknown, like file system data.
This is useful in the case where an application must handle data
but all other arguments will remain UTF-8 encoded.
The file_path parameter on the show action would be encoded as ASCII-8BIT,

end
end
@repositories = Repository.all
def index

end
@repo_name = params[:repo_name]
# params[:repo_name] remains UTF-8 encoded

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

param_encoding :show, :file_path, Encoding::ASCII_8BIT
# This specifies that file_path is not UTF-8 and is instead ASCII_8BIT
class RepositoryController < ActionController::Base

You can specify a binary (ASCII_8BIT) parameter with:

If not specified the default is UTF-8.
Specify the encoding for a parameter on an action.

def param_encoding(action, param, encoding)
  @_parameter_encodings[action.to_s][param.to_s] = encoding
end