"""Message

A very general (dumb) message class.

"""

from MiscUtils import NoDefault

class Message(object):

"""A very general message class.

Message is the abstract parent class for both Request and Response,

and implements the behavior that is generic to both.

Messages have:

* A set of arguments.

* A protocol.

* A content type and length.

FUTURE

* Support for different types of encodings

"""

## Init ##

def __init__(self):

self._args = {}

## Content ##

@staticmethod

def contentLength():

"""Return the length of the message body or -1 if not known."""

return -1

@staticmethod

def contentType():

"""Return the MIME type of the message body or None if not known."""

return None

## Protocol ##

@staticmethod

def protocol():

"""Return the protocol.

Returns the name and version of the protocol the message uses

in the form protocol/majorVersion.minorVersion, for example, HTTP/1.1.

"""

return None

## Arguments ##

# @@ 2000-05-10 ce: Are arguments really used for anything?

def arg(self, name, default=NoDefault):

if default is NoDefault:

return self._args[name]

else:

return self._args.get(name, default)

def setArg(self, name, value):

self._args[name] = value

def hasArg(self, name):

return name in self._args

def deleteArg(self, name):

del self._args[name]

def clearArgs(self):

self._args.clear()

def argNames(self):

"""Return a list of argument names."""

return self._args.keys()

## Exception reports ##

_exceptionReportAttrNames = ['args']

def writeExceptionReport(self, handler):

handler.writeTitle(self.__class__.__name__)

handler.writeAttrs(self, self._exceptionReportAttrNames)