"""HTTP responses"""
from datetime import datetime, timedelta
from time import time, gmtime, strftime, struct_time
from MiscUtils import NoDefault
from MiscUtils.DateInterval import timeDecode
from MiscUtils.Funcs import localTimeDelta
from Response import Response
from Cookie import Cookie
from HTTPExceptions import HTTPException, HTTPServerError
debug = False
class HTTPResponse(Response):
def __init__(self, transaction, strmOut, headers=None):
"""Initialize the request."""
Response.__init__(self, transaction, strmOut)
self._committed = False
if headers is None:
self._headers = {}
self.setHeader('Content-Type', 'text/html')
else:
self._headers = headers
self._cookies = {}
def protocol(self):
"""Return the name and version of the protocol."""
return self._transaction.request().protocol()
def header(self, name, default=NoDefault):
"""Return the value of the specified header."""
if default is NoDefault:
return self._headers[name.capitalize()]
else:
return self._headers.get(name.capitalize(), default)
def hasHeader(self, name):
return name.capitalize() in self._headers
def setHeader(self, name, value):
"""Set a specific header by name.
Parameters:
name: the header name
value: the header value
"""
assert not self._committed, "Headers have already been sent."
self._headers[name.capitalize()] = value
def headers(self, name=None):
"""Return all the headers.
Returns a dictionary-style object of all header objects contained by
this request.
"""
return self._headers
def clearHeaders(self):
"""Clear all the headers.
You might consider a setHeader('Content-Type', 'text/html')
or something similar after this.
"""
assert not self._committed, "Headers have already been sent."
self._headers = {}
def cookie(self, name):
"""Return the value of the specified cookie."""
return self._cookies[name]
def hasCookie(self, name):
"""Return True if the specified cookie is present."""
return name in self._cookies
def setCookie(self, name, value, path='/', expires='ONCLOSE',
secure=False):
"""Set a cookie.
You can also set the path (which defaults to /).
You can also set when it expires. It can expire:
'NOW': this is the same as trying to delete it, but it
doesn't really seem to work in IE
'ONCLOSE': the default behavior for cookies (expires when
the browser closes)
'NEVER': some time in the far, far future.
integer: a timestamp value
tuple or struct_time: a tuple, as created by the time module
datetime: a datetime.datetime object for the time (if without
time zone, assumed to be *local*, not GMT time)
timedelta: a duration counted from the present, e.g.,
datetime.timedelta(days=14) (2 weeks in the future)
'+...': a time in the future, '...' should be something like
1w (1 week), 3h46m (3:45), etc. You can use y (year),
b (month), w (week), d (day), h (hour), m (minute),
s (second). This is done by the MiscUtils.DateInterval.
"""
cookie = Cookie(name, value)
t = expires
if isinstance(t, basestring):
if t == 'ONCLOSE':
t = None
elif t == 'NOW':
cookie.delete()
return
elif t == 'NEVER':
t = gmtime()
t = (t[0] + 10,) + t[1:]
elif t.startswith('+'):
t = time() + timeDecode(t[1:])
if t:
if isinstance(t, (int, long, float)):
t = gmtime(t)
if isinstance(t, (tuple, struct_time)):
t = strftime("%a, %d-%b-%Y %H:%M:%S GMT", t)
if isinstance(t, timedelta):
t = datetime.now() + t
if isinstance(t, datetime):
d = t.utcoffset()
if d is None:
d = localTimeDelta()
t -= d
t = t.strftime("%a, %d-%b-%Y %H:%M:%S GMT")
cookie.setExpires(t)
if path:
cookie.setPath(path)
if secure:
cookie.setSecure(secure)
self.addCookie(cookie)
def addCookie(self, cookie):
"""Add a cookie that will be sent with this response.
cookie is a Cookie object instance. See WebKit.Cookie.
"""
assert not self._committed, "Headers have already been sent."
assert isinstance(cookie, Cookie)
self._cookies[cookie.name()] = cookie
def delCookie(self, name, path='/', secure=False):
"""Delete a cookie at the browser.
To do so, one has to create and send to the browser a cookie with
parameters that will cause the browser to delete it.
"""
if name in self._cookies:
self._cookies[name].delete()
else:
cookie = Cookie(name, None)
if path:
cookie.setPath(path)
if secure:
cookie.setSecure(secure)
cookie.delete()
self.addCookie(cookie)
def cookies(self):
"""Get all the cookies.
Returns a dictionary-style object of all Cookie objects that will
be sent with this response.
"""
return self._cookies
def clearCookies(self):
"""Clear all the cookies."""
assert not self._committed, "Headers have already been sent."
self._cookies = {}
def setStatus(self, code, msg=''):
"""Set the status code of the response, such as 200, 'OK'."""
assert not self._committed, "Headers have already been sent."
self.setHeader('Status', str(code) + ' ' + msg)
def sendError(self, code, msg=''):
"""Set the status code to the specified code and message."""
assert not self._committed, "Response already partially sent."
self.setStatus(code, msg)
def sendRedirect(self, url, status=None):
"""Redirect to another url.
This method sets the headers and content for the redirect, but does
NOT change the cookies. Use clearCookies() as appropriate.
See http://www.ietf.org/rfc/rfc2616 (section 10.3.3),
http://www.ietf.org/rfc/rfc3875 (section 6.2.3) and
http://support.microsoft.com/kb/176113
(removing cookies by IIS is considered a bug).
"""
assert not self._committed, "Headers have already been sent."
self.setHeader('Status', status or '302 Found')
self.setHeader('Location', url)
self.setHeader('Content-Type', 'text/html')
self.write('<html><body>This page has been redirected'
' to <a href="%s">%s</a>.</body></html>' % (url, url))
def sendRedirectPermanent(self, url):
"""Redirect permanently to another URL."""
self.sendRedirect(url, status='301 Moved Permanently')
def sendRedirectSeeOther(self, url):
"""Redirect to a URL that shall be retrieved with GET.
This method exists primarily to allow for the PRG pattern.
See http://en.wikipedia.org/wiki/Post/Redirect/Get
"""
self.sendRedirect(url, status='303 See Other')
def sendRedirectTemporary(self, url):
"""Redirect temporarily to another URL."""
self.sendRedirect(url, status='307 Temporary Redirect')
def write(self, charstr=None):
"""Write charstr to the response stream.
charstr must be convertible into an ordinary string.
Unicode strings with special characters must therefore
be encoded before they can be written.
"""
if charstr:
self._strmOut.write(str(charstr))
if not self._committed and self._strmOut._needCommit:
self.commit()
def flush(self, autoFlush=True):
"""Send all accumulated response data now.
Commits the response headers and tells the underlying stream to flush.
if autoFlush is true, the responseStream will flush itself automatically
from now on.
Caveat: Some webservers, especially on Win, will still buffer the output
from your servlet until it terminates before transmitting the results
to the browser. Also, server modules for Apache like mod_deflate or
mod_gzip may do buffering of their own that will cause flush() to not
result in data being sent immediately to the client. You can prevent
this by setting a no-gzip note in the Apache configuration, e.g.
SetEnvIf Request_URI ^/wk/MyServlet no-gzip=1
Even the browser may buffer its input before displaying it. For example,
Netscape buffered text until it received an end-of-line or the beginning
of a tag, and it didn't render tables until the end tag of the outermost
table was seen. Some Firefox add-ons also buffer response data before it
gets rendered. Some versions of MSIE will only start to display the page
after they have received 256 bytes of output, so you may need to send
extra whitespace before flushing to get MSIE to display the page.
"""
if not self._committed:
self.commit()
self._strmOut.flush()
self._strmOut.setAutoCommit(autoFlush)
def isCommitted(self):
"""Check whether response is already commited.
Checks whether the reponse has already been partially or completely sent.
If this returns true, no new headers/cookies can be added
to the response.
"""
return self._committed
def deliver(self):
"""Deliver response.
The final step in the processing cycle.
Not used for much with responseStreams added.
"""
if debug:
print "HTTPResponse deliver called"
self.recordEndTime()
if not self._committed:
self.commit()
def commit(self):
"""Commit response.
Write out all headers to the reponse stream, and tell the underlying
response stream it can start sending data.
"""
if debug:
print "HTTPResponse commit"
self.recordSession()
if self._transaction.errorOccurred():
err = self._transaction.error()
if not isinstance(err, HTTPException):
err = HTTPServerError()
self._transaction.setError(err)
self.setErrorHeaders(err)
self.writeHeaders()
self._committed = True
self._strmOut.commit()
def writeHeaders(self):
"""Write headers to the response stream. Used internally."""
if self._committed:
print "response.writeHeaders called when already committed"
return
if 'Status' in self._headers:
status = self._headers['Status']
del self._headers['Status']
else:
status = 'Location' in self._headers and '302 Found' or '200 OK'
head = ['Status: %s' % status]
head.extend(map(lambda h: '%s: %s' % h, self._headers.items()))
self._headers['Status'] = status
head.extend(map(lambda c: 'Set-Cookie: %s' % c.headerValue(),
self._cookies.values()))
head.extend(['']*2)
head = '\r\n'.join(head)
self._strmOut.prepend(head)
def recordSession(self):
"""Record session ID.
Invoked by commit() to record the session ID in the response
(if a session exists). This implementation sets a cookie for
that purpose. For people who don't like sweets, a future version
could check a setting and instead of using cookies, could parse
the HTML and update all the relevant URLs to include the session ID
(which implies a big performance hit). Or we could require site
developers to always pass their URLs through a function which adds
the session ID (which implies pain). Personally, I'd rather just
use cookies. You can experiment with different techniques by
subclassing Session and overriding this method. Just make sure
Application knows which "session" class to use.
It should be also considered to automatically add the server port
to the cookie name in order to distinguish application instances
running on different ports on the same server, or to use the port
cookie-attribute introduced with RFC 2965 for that purpose.
"""
trans = self._transaction
app = trans.application()
if not app.setting('UseCookieSessions'):
return
session = trans._session
if not session:
if debug:
print '>> recordSession: Did not set SID.'
return
request = trans.request()
sessionName = app.sessionName(trans)
identifier = session.identifier()
if session.isExpired() or session.timeout() == 0:
self.delCookie(sessionName, app.sessionCookiePath(trans),
request.isSecure() and app.setting('SecureSessionCookie'))
if debug:
print '>> recordSession: Removing SID', identifier
return
if request.hasCookie(sessionName):
if request.cookie(sessionName) == identifier:
if debug:
print '>> recordSession: Using SID', identifier
return
cookie = Cookie(app.sessionName(trans), identifier)
cookie.setPath(app.sessionCookiePath(trans))
if trans.request().isSecure():
cookie.setSecure(app.setting('SecureSessionCookie'))
self.addCookie(cookie)
if debug:
print '>> recordSession: Setting SID', identifier
def reset(self):
"""Reset the response (such as headers, cookies and contents)."""
assert not self._committed, \
"Cannot reset the response; it has already been sent."
self._headers = {}
self.setHeader('Content-Type', 'text/html')
self._cookies = {}
self._strmOut.clear()
def rawResponse(self):
"""Return the final contents of the response.
Don't invoke this method until after deliver().
Returns a dictionary representing the response containing only
strings, numbers, lists, tuples, etc. with no backreferences.
That means you don't need any special imports to examine the contents
and you can marshal it. Currently there are two keys. 'headers' is
list of tuples each of which contains two strings: the header and
it's value. 'contents' is a string (that may be binary, for example,
if an image were being returned).
"""
headers = []
for key, value in self._headers.items():
headers.append((key, value))
for cookie in self._cookies.values():
headers.append(('Set-Cookie', cookie.headerValue()))
return dict(headers=headers, contents=self._strmOut.buffer())
def size(self):
"""Return the size of the final contents of the response.
Don't invoke this method until after deliver().
"""
return self._strmOut.size()
def mergeTextHeaders(self, headerstr):
"""Merge text into our headers.
Given a string of headers (separated by newlines),
merge them into our headers.
"""
lines = headerstr.splitlines()
for line in lines:
header = line.split(':', 1)
if len(header) > 1:
self.setHeader(header[0], header[1].rstrip())
_exceptionReportAttrNames = Response._exceptionReportAttrNames + [
'committed', 'headers', 'cookies']
def setErrorHeaders(self, err):
"""Set error headers for an HTTPException."""
for header, value in err.headers().items():
self.setHeader(header, value)
self.setStatus(err.code(), err.codeMessage())
self.setHeader('Content-Type', 'text/html')
def displayError(self, err):
"""Display HTTPException errors, with status codes."""
assert not self._committed, "Already committed"
self._strmOut.clear()
self._strmOut.write(err.html())
uri = self._transaction.request().uri()
print 'HTTPResponse: %s: %s' % (uri, err.codeMessage())
self.commit()