##############################################################################
#
# Copyright (c) 2001, 2002 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (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.
#
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"""HTTP-related publisher interfaces.
"""
__docformat__ = "reStructuredText"
from zope.interface import Interface
from zope.interface import Attribute
from zope.interface import implements
from zope.interface.common.interfaces import IException
from zope.publisher.interfaces import IApplicationRequest
from zope.publisher.interfaces import IPublishTraverse
from zope.publisher.interfaces import IRequest
from zope.publisher.interfaces import IResponse
from zope.publisher.interfaces import IView
class IVirtualHostRequest(Interface):
"""The support for virtual hosts in Zope is very important.
In order to make virtual hosts working, we need to support several
methods in our Request object. This interface defines the required
methods.
"""
def setVirtualHostRoot(names):
"""Marks the currently traversed object as the root of a virtual host.
Any path elements traversed up to that
Set the names which compose the application path.
These are the path elements that appear in the beginning of
the generated URLs.
Should be called during traversal.
"""
def getVirtualHostRoot():
"""Returns the object which is the virtual host root for this request
Return None if setVirtualHostRoot hasn't been called.
"""
def setApplicationServer(host, proto='http', port=None):
"""Override the host, protocol and port parts of generated URLs.
This affects automatically inserted tags and URL getters
in the request, but not things like @@absolute_url views.
"""
def shiftNameToApplication():
"""Add the name being traversed to the application name
This is only allowed in the case where the name is the first name.
A Value error is raised if the shift can't be performed.
"""
class IHTTPApplicationRequest(IApplicationRequest, IVirtualHostRequest):
"""HTTP request data.
This object provides access to request data. This includes, the
input headers, server data, and cookies.
Request objects are created by the object publisher and will be
passed to published objects through the argument name, REQUEST.
The request object is a mapping object that represents a
collection of variable to value mappings. In addition, variables
are divided into four categories:
- Environment variables
These variables include input headers, server data, and other
request-related data. The variable names are as specified
in the CGI
specification
- Cookies
These are the cookie data, if present.
- Other
Data that may be set by an application object.
The request object may be used as a mapping object, in which case
values will be looked up in the order: environment variables,
other variables, cookies, and special.
"""
def __getitem__(key):
"""Return HTTP request data
Request data sre retrieved from one of:
- Environment variables
These variables include input headers, server data, and other
request-related data. The variable names are as specified
in the CGI
specification
- Cookies
These are the cookie data, if present.
Cookies are searched before environmental data.
"""
def getCookies():
"""Return the cookie data
Data are returned as a mapping object, mapping cookie name to value.
"""
return IMapping(str, str)
cookies = Attribute(
"""Request cookie data
This is a read-only mapping from variable name to value.
""")
def getHeader(name, default=None, literal=False):
"""Get a header value
Return the named HTTP header, or an optional default
argument or None if the header is not found. Note that
both original and CGI-ified header names are recognized,
e.g. 'Content-Type', 'CONTENT_TYPE' and 'HTTP_CONTENT_TYPE'
should all return the Content-Type header, if available.
If the literal argument is passed, the header is searched
'as is', eg: only if the case matches.
"""
headers = Attribute(
"""Request header data
This is a read-only mapping from variable name to value.
It does *not* support iteration.
""")
URL = Attribute(
"""Request URL data
When converted to a string, this gives the effective published URL.
This object can also be used as a mapping object. The key must
be an integer or a string that can be converted to an
integer. A non-negative integer returns a URL n steps from the
URL of the top-level application objects. A negative integer
gives a URL that is -n steps back from the effective URL.
For example, 'request.URL[-2]' is equivalent to the Zope 2
'request["URL2"]'. The notion is that this would be used in
path expressions, like 'request/URL/-2'.
""")
def getURL(level=0, path_only=False):
"""Return the published URL with level names removed from the end.
If path_only is true, then only a path will be returned.
"""
def getApplicationURL(depth=0, path_only=False):
"""Return the application URL plus depth steps
If path_only is true, then only a path will be returned.
"""
class IHTTPPublisher(IPublishTraverse):
"""HTTP Publisher"""
class IHTTPRequest(IRequest):
method = Attribute("Request method, normalized to upper case")
def setPathSuffix(steps):
"""Add additional traversal steps to be taken after all other traversal
This is used to handle HTTP request methods (except for GET
and POST in the case of browser requests) and XML-RPC methods.
"""
locale = Attribute(
"Return the locale object associated with this request.")
def setupLocale():
"""Setup the locale object based on languages returned by
IUserPreferredLanguages adapter.
"""
class IHTTPView(IView):
"HTTP View"
class IHTTPCredentials(Interface):
# TODO: Eventially this will be a different method
def _authUserPW():
"""Return (login, password) if there are basic credentials;
return None if there aren't."""
def unauthorized(challenge):
"""Issue a 401 Unauthorized error (asking for login/password).
The challenge is the value of the WWW-Authenticate header."""
class IHTTPApplicationResponse(Interface):
"""HTTP Response"""
def redirect(location, status=302, trusted=False):
"""Causes a redirection without raising an error.
By default redirects are untrusted which restricts target URLs to the
same host that the request was sent to.
If the `trusted` flag is set, redirects are allowed for any target
URL.
"""
class IHeaderOutput(Interface):
"""Interface for setting HTTP response headers.
This allows the HTTP server and the application to both set response
headers.
zope.publisher.http.HTTPResponse is optionally passed an
object which implements this interface in order to intermingle
its headers with the HTTP server's response headers,
and for the purpose of better logging.
"""
def setResponseStatus(status, reason):
"""Sets the status code and the accompanying message.
"""
def setResponseHeaders(mapping):
"""Sets headers. The headers must be Correctly-Cased.
"""
def appendResponseHeaders(lst):
"""Sets headers that can potentially repeat.
Takes a list of strings.
"""
def wroteResponseHeader():
"""Returns a flag indicating whether the response
header has already been sent.
"""
def setAuthUserName(name):
"""Sets the name of the authenticated user so the name can be logged.
"""
class IResult(Interface):
"""An iterable that provides the body data of the response.
For simplicity, an adapter to this interface may in fact return any
iterable, without needing to strictly have the iterable provide
IResult.
IMPORTANT: The result object may be held indefinitely by a server
and may be accessed by arbitrary threads. For that reason the result
should not hold on to any application resources (i.e., should not
have a connection to the database) and should be prepared to be
invoked from any thread.
This iterable should generally be appropriate for WSGI iteration.
Each element of the iteration should generally be much larger than a
character or line; concrete advice on chunk size is hard to come by,
but a single chunk of even 100 or 200 K is probably fine.
If the IResult is a string, then, the default iteration of
per-character is wildly too small. Because this is such a common
case, if a string is used as an IResult then this is special-cased
to simply convert to a tuple of one value, the string.
Adaptation to this interface provides the opportunity for efficient file
delivery, pipelining hooks, and more.
"""
def __iter__():
"""iterate over the values that should be returned as the result.
See IHTTPResponse.setResult.
"""
class IHTTPResponse(IResponse):
"""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 object as an argument
named 'RESPONSE'. A published object may also create its 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.
"""
authUser = Attribute('The authenticated user message.')
def getStatus():
"""Returns the current HTTP status code as an integer.
"""
def setStatus(status, reason=None):
"""Sets the HTTP status code of the response
The status parameter must be either an integer (preferred), a value
that can be converted to an integer using the int() function,
or one of the standard status messages listed in the status_codes
dict of the zope.publisher.http module (including "OK", "NotFound",
and so on). If the parameter is some other value, the status will
be set to 500.
The reason parameter is a short message to be sent with the status
code to the client. If reason is not provided, a standard
reason will be supplied, falling back to "Unknown" for unregistered
status codes.
"""
def getStatusString():
"""Return the status followed by the reason."""
def setHeader(name, value, literal=False):
"""Sets an HTTP return header "name" with value "value"
The previous value is cleared. 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.
"""
def addHeader(name, value):
"""Add an HTTP Header
Sets a new HTTP return header with the given value, while retaining
any previously set headers with the same name.
"""
def getHeader(name, default=None):
"""Gets a header value
Returns the value associated with a HTTP return header, or
'default' if no such header has been set in the response
yet.
"""
def getHeaders():
"""Returns a list of header name, value tuples.
"""
def appendToCookie(name, value):
"""Append text to a cookie value
If a value for the cookie has previously been set, the new
value is appended to the old one separated by a colon.
"""
def expireCookie(name, **kw):
"""Causes an HTTP cookie to be removed from the browser
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.
If the value of a keyword argument is None, it will be ignored.
"""
def setCookie(name, value, **kw):
"""Sets 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.
If the value of a keyword argument is None, it will be ignored.
"""
def getCookie(name, default=None):
"""Gets HTTP cookie data as a dict
Returns the dict of values associated with an HTTP cookie set in the
response, or 'default' if no such cookie has been set in the response
yet.
"""
def setResult(result):
"""Sets response result value based on input.
Input is usually a unicode string, a string, None, or an object
that can be adapted to IResult with the request. The end result
is an iterable such as WSGI prefers, determined by following the
process described below.
Try to adapt the given input, with the request, to IResult
(found above in this file). If this fails, and the original
value was a string, use the string as the result; or if was
None, use an empty string as the result; and if it was anything
else, raise a TypeError.
If the result of the above (the adaptation or the default
handling of string and None) is unicode, encode it (to the
preferred encoding found by adapting the request to
zope.i18n.interfaces.IUserPreferredCharsets, usually implemented
by looking at the HTTP Accept-Charset header in the request, and
defaulting to utf-8) and set the proper encoding information on
the Content-Type header, if present. Otherwise (the end result
was not unicode) application is responsible for setting
Content-Type header encoding value as necessary.
If the result of the above is a string, set the Content-Length
header, and make the string be the single member of an iterable
such as a tuple (to send large chunks over the wire; see
discussion in the IResult interface). Otherwise (the end result
was not a string) application is responsible for setting
Content-Length header as necessary.
Set the result of all of the above as the response's result. If
the status has not been set, set it to 200 (OK). """
def consumeBody():
"""Returns the response body as a string.
Note that this function can be only requested once, since it is
constructed from the result.
"""
def consumeBodyIter():
"""Returns the response body as an iterable.
Note that this function can be only requested once, since it is
constructed from the result.
"""
class IHTTPVirtualHostChangedEvent(Interface):
"""The host, port and/or the application path have changed.
The request referred to in this event implements at least the
IHTTPAppliationRequest interface.
"""
request = Attribute(u'The application request whose virtual host info has '
u'been altered')
class IHTTPException(Interface):
"""Marker interface for http exceptions views
"""
pass
class IMethodNotAllowed(IException):
"""An exception that signals the 405 Method Not Allowed HTTP error"""
object = Attribute("""The object on which the error occurred""")
request = Attribute("""The request in which the error occurred""")
class MethodNotAllowed(Exception):
"""An exception that signals the 405 Method Not Allowed HTTP error"""
implements(IMethodNotAllowed)
def __init__(self, object, request):
self.object = object
self.request = request
def __str__(self):
return "%r, %r" % (self.object, self.request)