#############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
'''CGI Response Output formatter
$Id: HTTPResponse.py,v 1.69.4.1 2002/09/25 16:06:25 jeremy Exp $'''
__version__ = '$Revision: 1.69.4.1 $'[11:-2]
import types, os, sys, re
import zlib, struct
from string import translate,maketrans
from types import StringType,InstanceType,LongType,UnicodeType
from BaseResponse import BaseResponse
from zExceptions import Unauthorized
from zExceptions.ExceptionFormatter import format_exception
nl2sp = maketrans('\n',' ')
# Enable APPEND_TRACEBACKS to make Zope append tracebacks like it used to,
# but a better solution is to make standard_error_message display error_tb.
APPEND_TRACEBACKS = 0
status_reasons = {
100: 'Continue',
101: 'Switching Protocols',
102: 'Processing',
200: 'OK',
201: 'Created',
202: 'Accepted',
203: 'Non-Authoritative Information',
204: 'No Content',
205: 'Reset Content',
206: 'Partial Content',
207: 'Multi-Status',
300: 'Multiple Choices',
301: 'Moved Permanently',
302: 'Moved Temporarily',
303: 'See Other',
304: 'Not Modified',
305: 'Use Proxy',
307: 'Temporary Redirect',
400: 'Bad Request',
401: 'Unauthorized',
402: 'Payment Required',
403: 'Forbidden',
404: 'Not Found',
405: 'Method Not Allowed',
406: 'Not Acceptable',
407: 'Proxy Authentication Required',
408: 'Request Time-out',
409: 'Conflict',
410: 'Gone',
411: 'Length Required',
412: 'Precondition Failed',
413: 'Request Entity Too Large',
414: 'Request-URI Too Large',
415: 'Unsupported Media Type',
416: 'Requested range not satisfiable',
417: 'Expectation Failed',
422: 'Unprocessable Entity',
423: 'Locked',
424: 'Failed Dependency',
500: 'Internal Server Error',
501: 'Not Implemented',
502: 'Bad Gateway',
503: 'Service Unavailable',
504: 'Gateway Time-out',
505: 'HTTP Version not supported',
507: 'Insufficient Storage',
}
status_codes = {}
# Add mappings for builtin exceptions and
# provide text -> error code lookups.
for key, val in status_reasons.items():
status_codes[''.join(val.split(' ')).lower()] = key
status_codes[val.lower()] = key
status_codes[key] = key
status_codes[str(key)] = key
en = filter(lambda n: n[-5:] == 'Error', dir(__builtins__))
for name in en:
status_codes[name.lower()] = 500
status_codes['nameerror'] = 503
status_codes['keyerror'] = 503
status_codes['redirect'] = 300
start_of_header_search = re.compile('(<head[^>]*>)', re.IGNORECASE).search
accumulate_header = {'set-cookie': 1}.has_key
_gzip_header = ("\037\213" # magic
"\010" # compression method
"\000" # flags
"\000\000\000\000" # time
"\002"
"\377")
uncompressableMimeMajorTypes = ('image',) # these mime major types should
# not be gzip content encoded
# The environment variable DONT_GZIP_MAJOR_MIME_TYPES can be set to a list
# of comma seperated mime major types which should also not be compressed
otherTypes = os.environ.get('DONT_GZIP_MAJOR_MIME_TYPES','').lower()
if otherTypes:
uncompressableMimeMajorTypes += tuple(otherTypes.split(','))
class HTTPResponse(BaseResponse):
"""\
An object representation of an HTTP response.
The Response type encapsulates all possible responses to HTTP
requests. Responses are normally created by the object publisher.
A published object may recieve the response abject as an argument
named 'RESPONSE'. A published object may also create it's own
response object. Normally, published objects use response objects
to:
- Provide specific control over output headers,
- Set cookies, or
- Provide stream-oriented output.
If stream oriented output is used, then the response object
passed into the object must be used.
""" #'
accumulated_headers = ''
body = ''
realm = 'Zope'
_error_format = 'text/html'
_locked_status = 0
# Indicate if setBody should content-compress output.
# 0 - no compression
# 1 - compress if accept-encoding ok
# 2 - ignore accept-encoding (i.e. force)
use_HTTP_content_compression = 0
def __init__(self,body='',status=200,headers=None,
stdout=sys.stdout, stderr=sys.stderr,):
'''\
Creates a new response. In effect, the constructor calls
"self.setBody(body); self.setStatus(status); for name in
headers.keys(): self.setHeader(name, headers[name])"
'''
if headers is None:
headers = {}
self.headers = headers
if status == 200:
self.status = 200
self.errmsg = 'OK'
headers['status'] = "200 OK"
else:
self.setStatus(status)
self.base = ''
if body:
self.setBody(body)
self.cookies = {}
self.stdout = stdout
self.stderr = stderr
def retry(self):
"""Return a response object to be used in a retry attempt
"""
# This implementation is a bit lame, because it assumes that
# only stdout stderr were passed to the constructor. OTOH, I
# think that that's all that is ever passed.
return self.__class__(stdout=self.stdout, stderr=self.stderr)
_shutdown_flag = None
def _requestShutdown(self, exitCode=0):
"""Request that the server shut down with exitCode after fulfilling
the current request."""
sys.ZServerExitCode = exitCode
self._shutdown_flag = 1
def _shutdownRequested(self):
"""Returns true if this request requested a server shutdown."""
return self._shutdown_flag is not None
def setStatus(self, status, reason=None):
'''\
Sets the HTTP status code of the response; the argument may
either be an integer or a string from OKCreatedAccepted import
NoContent, MovedPermanently, MovedTemporarily,
NotModified, BadRequest, Unauthorized, Forbidden,
NotFound, InternalError, NotImplemented, BadGateway,
ServiceUnavailable } that will be converted to the correct
integer value. '''
if self._locked_status:
# Don't change the response status.
# It has already been determined.
return
if type(status) is types.StringType:
status = status.lower()
if status_codes.has_key(status):
status = status_codes[status]
else:
status = 500
self.status = status
if reason is None:
if status_reasons.has_key(status):
reason = status_reasons[status]
else:
reason = 'Unknown'
self.setHeader('Status', "%d %s" % (status,str(reason)))
self.errmsg = reason
def setHeader(self, name, value, literal=0):
'''\
Sets an HTTP return header "name" with value "value", clearing
the previous value set for the header, if one exists. If the
literal flag is true, the case of the header name is preserved,
otherwise word-capitalization will be performed on the header
name on output.'''
key = name.lower()
if accumulate_header(key):
self.accumulated_headers = (
"%s%s: %s\n" % (self.accumulated_headers, name, value))
return
name = literal and name or key
self.headers[name] = value
def addHeader(self, name, value):
'''\
Set a new HTTP return header with the given value, while retaining
any previously set headers with the same name.'''
self.accumulated_headers = (
"%s%s: %s\n" % (self.accumulated_headers, name, value))
__setitem__ = setHeader
def setBody(self, body, title='', is_error=0,
bogus_str_search=re.compile(" [a-fA-F0-9]+>$").search,
latin1_alias_match=re.compile(
r'text/html(\s*;\s*charset=((latin)|(latin[-_]?1)|'
r'(cp1252)|(cp819)|(csISOLatin1)|(IBM819)|(iso-ir-100)|'
r'(iso[-_]8859[-_]1(:1987)?)))?$',re.I).match
):
'''\
Set the body of the response
Sets the return body equal to the (string) argument "body". Also
updates the "content-length" return header.
You can also specify a title, in which case the title and body
will be wrapped up in html, head, title, and body tags.
If the body is a 2-element tuple, then it will be treated
as (title,body)
If is_error is true then the HTML will be formatted as a Zope error
message instead of a generic HTML page.
'''
if not body:
return self
if type(body) is types.TupleType and len(body) == 2:
title,body = body
if type(body) is not types.StringType:
if hasattr(body,'asHTML'):
body = body.asHTML()
if type(body) is UnicodeType:
body = self._encode_unicode(body)
elif type(body) is StringType:
pass
else:
try:
body = str(body)
except UnicodeError:
body = self._encode_unicode(unicode(body))
l = len(body)
if ((l < 200) and body[:1] == '<' and body.find('>') == l-1 and
bogus_str_search(body) is not None):
self.notFoundError(body[1:-1])
else:
if(title):
title = str(title)
if not is_error:
self.body = self._html(title, body)
else:
self.body = self._error_html(title, body)
else:
self.body = body
if not self.headers.has_key('content-type'):
isHTML = self.isHTML(self.body)
if isHTML:
c = 'text/html'
else:
c = 'text/plain'
self.setHeader('content-type', c)
# Some browsers interpret certain characters in Latin 1 as html
# special characters. These cannot be removed by html_quote,
# because this is not the case for all encodings.
content_type = self.headers['content-type']
if content_type == 'text/html' or latin1_alias_match(
content_type) is not None:
body = '<'.join(body.split('\213'))
body = '>'.join(body.split('\233'))
self.setHeader('content-length', len(self.body))
self.insertBase()
if self.use_HTTP_content_compression and \
not self.headers.get('content-encoding',None):
# use HTTP content encoding to compress body contents unless
# this response already has another type of content encoding
if content_type.split('/')[0] not in uncompressableMimeMajorTypes:
# only compress if not listed as uncompressable
body = self.body
startlen = len(body)
co = zlib.compressobj(6,zlib.DEFLATED,-zlib.MAX_WBITS,
zlib.DEF_MEM_LEVEL,0)
chunks = [_gzip_header, co.compress(body),
co.flush(),
struct.pack("<ll",zlib.crc32(body),startlen)]
z = "".join(chunks)
newlen = len(z)
if newlen < startlen:
self.body = z
self.setHeader('content-length', newlen)
self.setHeader('content-encoding','gzip')
if self.use_HTTP_content_compression == 1:
# use_HTTP_content_compression == 1 if force was
# NOT used in enableHTTPCompression().
# If we forced it, then Accept-Encoding
# was ignored anyway, so cache should not
# vary on it. Otherwise if not forced, cache should
# respect Accept-Encoding client header
self.appendHeader('Vary','Accept-Encoding')
return self
def enableHTTPCompression(self,REQUEST={},force=0,disable=0,query=0):
"""Enable HTTP Content Encoding with gzip compression if possible
REQUEST -- used to check if client can accept compression
force -- set true to ignore REQUEST headers
disable -- set true to disable compression
query -- just return if compression has been previously requested
returns -- 1 if compression will be attempted, 2 if compression
is forced, 0 if no compression
The HTTP specification allows for transfer encoding and content
encoding. Unfortunately many web browsers still do not support
transfer encoding, but they all seem to support content encoding.
This function is designed to be called on each request to specify
on a request-by-request basis that the response content should
be compressed. This is quite useful for xml-rpc transactions, where
compression rates of 90% or more can be achieved for text data.
The REQUEST headers are used to determine if the client accepts
gzip content encoding. The force parameter can force the use
of gzip encoding regardless of REQUEST, and the disable parameter
can be used to "turn off" previously enabled encoding (but note
that any existing content-encoding header will not be changed).
The query parameter can be used to determine the if compression
has been previously requested.
In setBody, the major mime type is used to determine if content
encoding should actually be performed.
By default, image types are not compressed.
Additional major mime types can be specified by setting the
environment variable DONT_GZIP_MAJOR_MIME_TYPES to a comma-seperated
list of major mime types that should also not be gzip compressed.
"""
if query:
return self.use_HTTP_content_compression
elif disable:
# in the future, a gzip cache manager will need to ensure that
# compression is off
self.use_HTTP_content_compression = 0
elif (force or
(REQUEST.get('HTTP_ACCEPT_ENCODING','').find('gzip') != -1)):
if force:
self.use_HTTP_content_compression = 2
else:
self.use_HTTP_content_compression = 1
return self.use_HTTP_content_compression
def _encode_unicode(self,body,
charset_re=re.compile(r'text/[0-9a-z]+\s*;\s*' +
r'charset=([-_0-9a-z]+' +
r')(?:(?:\s*;)|\Z)',
re.IGNORECASE)):
# Encode the Unicode data as requested
if self.headers.has_key('content-type'):
match = charset_re.match(self.headers['content-type'])
if match:
encoding = match.group(1)
return body.encode(encoding)
# Use the default character encoding
return body.encode('latin1','replace')
def setBase(self,base):
'Set the base URL for the returned document.'
if not base.endswith('/'):
base = base+'/'
self.base = base
def insertBase(self,
base_re_search=re.compile('(<base.*?>)',re.I).search
):
# Only insert a base tag if content appears to be html.
content_type = self.headers.get('content-type', '').split(';')[0]
if content_type and (content_type != 'text/html'):
return
if self.base:
body = self.body
if body:
match = start_of_header_search(body)
if match is not None:
index = match.start(0) + len(match.group(0))
ibase = base_re_search(body)
if ibase is None:
self.body = ('%s\n<base href="%s" />\n%s' %
(body[:index], self.base, body[index:]))
self.setHeader('content-length', len(self.body))
def appendCookie(self, name, value):
'''\
Returns an HTTP header that sets a cookie on cookie-enabled
browsers with a key "name" and value "value". If a value for the
cookie has previously been set in the response object, the new
value is appended to the old one separated by a colon. '''
cookies = self.cookies
if cookies.has_key(name):
cookie = cookies[name]
else:
cookie = cookies[name] = {}
if cookie.has_key('value'):
cookie['value'] = '%s:%s' % (cookie['value'], value)
else:
cookie['value'] = value
def expireCookie(self, name, **kw):
'''\
Cause an HTTP cookie to be removed from thebrowser import
The response will include an HTTP header that will remove the cookie
corresponding to "name" on the client, if one exists. This is
accomplished by sending a new cookie with an expiration date
that has already passed. Note that some clients require a path
to be specified - this path must exactly match the path given
when creating the cookie. The path can be specified as a keyword
argument.
'''
dict = {'max_age':0, 'expires':'Wed, 31-Dec-97 23:59:59 GMT'}
for k, v in kw.items():
dict[k] = v
apply(HTTPResponse.setCookie, (self, name, 'deleted'), dict)
def setCookie(self,name,value,**kw):
'''\
Set an HTTP cookie on the browser
The response will include an HTTP header that sets a cookie on
cookie-enabled browsers with a key "name" and value
"value". This overwrites any previously set value for the
cookie in the Response object.
'''
cookies = self.cookies
if cookies.has_key(name):
cookie = cookies[name]
else:
cookie = cookies[name] = {}
for k, v in kw.items():
cookie[k] = v
cookie['value'] = value
def appendHeader(self, name, value, delimiter=","):
'''\
Append a value to a header.
Sets an HTTP return header "name" with value "value",
appending it following a comma if there was a previous value
set for the header. '''
headers = self.headers
if headers.has_key(name):
h = headers[name]
h = "%s%s\n\t%s" % (h,delimiter,value)
else:
h = value
self.setHeader(name,h)
def isHTML(self, s):
s = s.lstrip()
# Note that the string can be big, so s.lower().startswith() is more
# expensive than s[:n].lower().
if (s[:6].lower() == '<html>' or s[:14].lower() == '<!doctype html'):
return 1
if s.find('</') > 0:
return 1
return 0
def quoteHTML(self,text,
subs={'&':'&', "<":'<', ">":'>', '\"':'"'}
):
for ent in '&<>\"':
if text.find( ent) >= 0:
text = subs[ent].join(text.split(ent))
return text
def _traceback(self, t, v, tb, as_html=1):
tb = format_exception(t, v, tb, as_html=as_html)
return '\n'.join(tb)
def redirect(self, location, status=302, lock=0):
"""Cause a redirection without raising an error"""
self.setStatus(status)
self.setHeader('Location', location)
if lock:
# Don't let anything change the status code.
# The "lock" argument needs to be set when redirecting
# from a standard_error_message page.
self._locked_status = 1
return location
def _html(self,title,body):
return ("<html>\n"
"<head>\n<title>%s</title>\n</head>\n"
"<body>\n%s\n</body>\n"
"</html>\n" % (title,body))
def _error_html(self,title,body):
# XXX could this try to use standard_error_message somehow?
return ("""\
<TABLE BORDER="0" WIDTH="100%">
<TR VALIGN="TOP">
<TD WIDTH="10%" ALIGN="CENTER">
</TD>
<TD WIDTH="90%">
<H2>Site Error</H2>
<P>An error was encountered while publishing this resource.
</P>""" + \
"""
<P><STRONG>%s</STRONG></P>
%s""" %(title,body) + \
"""
<HR NOSHADE>
<P>Troubleshooting Suggestions</P>
<UL>
<LI>The URL may be incorrect.</LI>
<LI>The parameters passed to this resource may be incorrect.</LI>
<LI>A resource that this resource relies on may be
encountering an error.</LI>
</UL>
<P>For more detailed information about the error, please
refer to the HTML source for this page.
</P>
<P>If the error persists please contact the site maintainer.
Thank you for your patience.
</P>
</TD></TR>
</TABLE>""")
def notFoundError(self,entry='Unknown'):
self.setStatus(404)
raise 'NotFound',self._error_html(
"Resource not found",
"Sorry, the requested resource does not exist." +
"<p>Check the URL and try again.</p>" +
"<p><b>Resource:</b> %s</p>" % self.quoteHTML(entry))
forbiddenError = notFoundError # If a resource is forbidden,
# why reveal that it exists?
def debugError(self,entry):
raise 'NotFound',self._error_html(
"Debugging Notice",
"Zope has encountered a problem publishing your object.<p>"
"\n%s" % entry)
def badRequestError(self,name):
self.setStatus(400)
if re.match('^[A-Z_0-9]+$',name):
raise 'InternalError', self._error_html(
"Internal Error",
"Sorry, an internal error occurred in this resource.")
raise 'BadRequest',self._error_html(
"Invalid request",
"The parameter, <em>%s</em>, " % name +
"was omitted from the request.<p>" +
"Make sure to specify all required parameters, " +
"and try the request again."
)
def _unauthorized(self):
realm = self.realm
if realm:
self.setHeader('WWW-Authenticate', 'basic realm="%s"' % realm, 1)
def unauthorized(self):
self._unauthorized()
m = "<strong>You are not authorized to access this resource.</strong>"
if self.debug_mode:
if self._auth:
m = m + '<p>\nUsername and password are not correct.'
else:
m = m + '<p>\nNo Authorization header found.'
raise Unauthorized, m
def exception(self, fatal=0, info=None,
absuri_match=re.compile(r'\w+://[\w\.]+').match,
tag_search=re.compile('[a-zA-Z]>').search,
abort=1
):
if type(info) is type(()) and len(info) == 3:
t, v, tb = info
else:
t, v, tb = sys.exc_info()
if t == 'Unauthorized' or t == Unauthorized or (
isinstance(t, types.ClassType) and issubclass(t, Unauthorized)):
t = 'Unauthorized'
self._unauthorized()
stb = tb # note alias between tb and stb
try:
# Try to capture exception info for bci calls
et = translate(str(t), nl2sp)
self.setHeader('bobo-exception-type', et)
ev = translate(str(v), nl2sp)
if ev.find( '<html>') >= 0:
ev = 'bobo exception'
self.setHeader('bobo-exception-value', ev[:255])
# Get the tb tail, which is the interesting part:
while tb.tb_next is not None:
tb = tb.tb_next
el = str(tb.tb_lineno)
ef = str(tb.tb_frame.f_code.co_filename)
self.setHeader('bobo-exception-file', ef)
self.setHeader('bobo-exception-line', el)
except:
# Dont try so hard that we cause other problems ;)
pass
tb = stb # original traceback
del stb
self.setStatus(t)
if self.status >= 300 and self.status < 400:
if type(v) == types.StringType and absuri_match(v) is not None:
if self.status == 300:
self.setStatus(302)
self.setHeader('location', v)
tb = None # just one path covered
return self
else:
try:
l, b = v
if (type(l) == types.StringType
and absuri_match(l) is not None):
if self.status == 300:
self.setStatus(302)
self.setHeader('location', l)
self.setBody(b)
tb = None # one more patch covered
return self
except:
pass # tb is not cleared in this case
b = v
if isinstance(b, Exception):
try:
b = str(b)
except:
b = '<unprintable %s object>' % type(b).__name__
if fatal and t is SystemExit and v.code == 0:
body = self.setBody(
(str(t),
'Zope has exited normally.<p>' + self._traceback(t, v, tb)),
is_error=1)
else:
try:
match = tag_search(b)
except TypeError:
match = None
if match is None:
body = self.setBody(
(str(t),
'Sorry, a site error occurred.<p>'
+ self._traceback(t, v, tb)),
is_error=1)
elif self.isHTML(b):
# error is an HTML document, not just a snippet of html
if APPEND_TRACEBACKS:
body = self.setBody(b + self._traceback(
t, '(see above)', tb), is_error=1)
else:
body = self.setBody(b, is_error=1)
else:
body = self.setBody(
(str(t), b + self._traceback(t,'(see above)', tb, 0)),
is_error=1)
del tb
return body
_wrote = None
def _cookie_list(self):
cookie_list = []
for name, attrs in self.cookies.items():
# Note that as of May 98, IE4 ignores cookies with
# quoted cookie attr values, so only the value part
# of name=value pairs may be quoted.
cookie = 'Set-Cookie: %s="%s"' % (name, attrs['value'])
for name, v in attrs.items():
name = name.lower()
if name == 'expires':
cookie = '%s; Expires=%s' % (cookie,v)
elif name == 'domain':
cookie = '%s; Domain=%s' % (cookie,v)
elif name == 'path':
cookie = '%s; Path=%s' % (cookie,v)
elif name == 'max_age':
cookie = '%s; Max-Age=%s' % (cookie,v)
elif name == 'comment':
cookie = '%s; Comment=%s' % (cookie,v)
elif name == 'secure' and v:
cookie = '%s; Secure' % cookie
cookie_list.append(cookie)
# Should really check size of cookies here!
return cookie_list
def __str__(self,
html_search=re.compile('<html>',re.I).search,
):
if self._wrote:
return '' # Streaming output was used.
headers = self.headers
body = self.body
if not headers.has_key('content-length') and \
not headers.has_key('transfer-encoding'):
self.setHeader('content-length',len(body))
headersl = []
append = headersl.append
# status header must come first.
append("Status: %s" % headers.get('status', '200 OK'))
append("X-Powered-By: Zope (www.zope.org), Python (www.python.org)")
if headers.has_key('status'):
del headers['status']
for key, val in headers.items():
if key.lower() == key:
# only change non-literal header names
key = "%s%s" % (key[:1].upper(), key[1:])
start = 0
l = key.find('-',start)
while l >= start:
key = "%s-%s%s" % (key[:l],key[l+1:l+2].upper(),key[l+2:])
start = l + 1
l = key.find('-', start)
append("%s: %s" % (key, val))
if self.cookies:
headersl = headersl+self._cookie_list()
headersl[len(headersl):] = [self.accumulated_headers, body]
return '\n'.join(headersl)
def write(self,data):
"""\
Return data as a stream
HTML data may be returned using a stream-oriented interface.
This allows the browser to display partial results while
computation of a response to proceed.
The published object should first set any output headers or
cookies on the response object.
Note that published objects must not generate any errors
after beginning stream-oriented output.
"""
if not self._wrote:
self.outputBody()
self._wrote = 1
self.stdout.flush()
self.stdout.write(data)
|