"""
WSGI HTTP utility code
"""
# for utility functions
import cgi
# for header handling
import wsgiref.headers
# for path handling
import os.path
class Request (object) :
"""
HTTP Request with associated metadata
"""
def __init__ (self, env) :
"""
Parse env data
"""
# store env
self.env = env
# get the querystring
self.arg_str = env.get('QUERY_STRING', '')
# parse query args
self.arg_dict = cgi.parse_qs(self.arg_str, True)
def get_script_dir (self) :
"""
Returns the URL path to the requested script's directory with no trailing slash, i.e.
/ ->
/foo.cgi ->
/foo/bar.cgi -> /foo
"""
return os.path.dirname(self.env['SCRIPT_NAME'])
def get_page_name (self) :
"""
Returns the requested page path with no leading slash, i.e.
/foo.cgi ->
/foo.cgi/ ->
/foo.cgi/bar -> bar
/foo.cgi/quux/ -> quux/
"""
return os.path.normpath(self.env['PATH_INFO']).lstrip('/')
class Response (object) :
"""
HTTP Response with headers and data
"""
def __init__ (self, data, content_type='text/html', status='200 OK', charset='utf8') :
"""
Create the response. The Content-type header is built from the given values. The given \a data must be
either a str (which is sent plain), an unicode object (which is encoded with the relevant charset), or
None, whereupon an empty response body is sent. The content_type argument can also be forced to None to
not send a Content-type header (e.g. for redirects)
"""
# store info
self.status = status
self.data = data
self.charset = charset
# headers
self.headers = wsgiref.headers.Headers([])
# add Content-type header?
if content_type :
self.add_header('Content-type', content_type, charset=charset)
def add_header (self, name, value, **params) :
"""
Add response header with the given name/value, plus option params
XXX: uses the wsgiref.headers code, not sure how that behaves re multiple headers with the same name, etc
"""
self.headers.add_header(name, value, **params)
def get_status (self) :
"""
Returns response status string (XXX Foo)
"""
return self.status
def get_headers (self) :
"""
Returns the list of header (name, value) pairs
"""
return self.headers.items()
def get_data (self) :
"""
Returns the response data - as an encoded string
"""
if self.data :
return self.data.encode(self.charset)
else :
return ''
class ErrorResponse (Response) :
"""
A response with an error code / message
"""
def __init__ (self, status, message, details=None) :
"""
Build a plain error message response with the given status/message
@param status HTTP status code
@param message short message to describe errors
@param details optional details, plaintext
"""
data = """\
<html><head><title>%(title)s</title></head><body>
<h1>%(title)s</h1>
<p>%(message)s</p>
%(details)s
</body></html>
""" % dict(
title = status,
message = message,
details = '<pre>%s</pre>' % details if details else ''
)
super(ErrorResponse, self).__init__(data, status=status)
class ResponseError (Exception) :
"""
An exception that results in a specfic 4xx ErrorResponse message to the client
"""
def __init__ (self, message, status='400 Bad Request', details=None) :
self.status = status
self.message = message
self.details = details
super(ResponseError, self).__init__(message)
def get_response (self) :
return ErrorResponse(self.status, self.message, self.details)
class Redirect (Response) :
"""
Redirect response
"""
def __init__ (self, url) :
"""
Redirect to given *absolute* URL
"""
# no content-type or data
super(Redirect, self).__init__(None, content_type=None, status='302 Found')
# add Location: header
self.add_header("Location", url)