def __init__(self, response=None, status=None, headers=None,
mimetype=None, content_type=None, direct_passthrough=False):
if isinstance(headers, Headers):
self.headers = headers
elif not headers:
self.headers = Headers()
else:
self.headers = Headers(headers)
if content_type is None:
if mimetype is None and 'content-type' not in self.headers:
mimetype = self.default_mimetype
if mimetype is not None:
mimetype = get_content_type(mimetype, self.charset)
content_type = mimetype
if content_type is not None:
self.headers['Content-Type'] = content_type
if status is None:
status = self.default_status
if isinstance(status, int):
self.status_code = status
else:
self.status = status
self.direct_passthrough = direct_passthrough
self._on_close = []
# we set the response after the headers so that if a class changes
# the charset attribute, the data is set in the correct charset.
if response is None:
self.response = []
elif isinstance(response, (str, bytes, bytearray)):
self.set_data(response)
else:
self.response = response
def __init__(self, path='/', base_url=None, query_string=None,
method='GET', input_stream=None, content_type=None,
content_length=None, errors_stream=None, multithread=False,
multiprocess=False, run_once=False, headers=None, data=None,
environ_base=None, environ_overrides=None, charset='utf-8'):
path_s = make_literal_wrapper(path)
if query_string is None and path_s('?') in path:
path, query_string = path.split(path_s('?'), 1)
self.charset = charset
self.path = iri_to_uri(path)
if base_url is not None:
base_url = url_fix(iri_to_uri(base_url, charset), charset)
self.base_url = base_url
if isinstance(query_string, (bytes, str)):
self.query_string = query_string
else:
if query_string is None:
query_string = MultiDict()
elif not isinstance(query_string, MultiDict):
query_string = MultiDict(query_string)
self.args = query_string
self.method = method
if headers is None:
headers = Headers()
elif not isinstance(headers, Headers):
headers = Headers(headers)
self.headers = headers
if content_type is not None:
self.content_type = content_type
if errors_stream is None:
errors_stream = sys.stderr
self.errors_stream = errors_stream
self.multithread = multithread
self.multiprocess = multiprocess
self.run_once = run_once
self.environ_base = environ_base
self.environ_overrides = environ_overrides
self.input_stream = input_stream
self.content_length = content_length
self.closed = False
if data:
if input_stream is not None:
raise TypeError('can\'t provide input stream and data')
if isinstance(data, str):
data = data.encode(self.charset)
if isinstance(data, bytes):
self.input_stream = BytesIO(data)
if self.content_length is None:
self.content_length = len(data)
else:
for key, value in _iter_data(data):
if (
isinstance(value, (tuple, dict)) or
hasattr(value, 'read')
):
self._add_file_from_data(key, value)
else:
self.form.setlistdefault(key).append(value)
def run_wsgi_app(app, environ, buffered=False):
"""Return a tuple in the form (app_iter, status, headers) of the
application output. This works best if you pass it an application that
returns an iterator all the time.
Sometimes applications may use the `write()` callable returned
by the `start_response` function. This tries to resolve such edge
cases automatically. But if you don't get the expected output you
should set `buffered` to `True` which enforces buffering.
If passed an invalid WSGI application the behavior of this function is
undefined. Never pass non-conforming WSGI applications to this function.
:param app:
The application to execute.
:param environ:
The wsgi environment in which to execute the application.
:param buffered:
Set to `True` to enforce buffering.
:return:
Tuple on the form ``(app_iter, status, headers)``
"""
response = []
buffer = []
def start_response(status, headers, exc_info=None):
if exc_info is not None:
exc_type, exc_value, exc_traceback = exc_info
if exc_value.__traceback__ is not exc_traceback:
raise exc_value.with_traceback()
raise exc_value
response[:] = [status, headers]
return buffer.append
app_rv = app(environ, start_response)
close_func = getattr(app_rv, 'close', None)
app_iter = iter(app_rv)
# when buffering we emit the close call early and convert the
# application iterator into a regular list
if buffered:
try:
app_iter = list(app_iter)
finally:
if close_func is not None:
close_func()
# otherwise we iterate the application iter until we have a response, chain
# the already received data with the already collected data and wrap it in
# a new `ClosingIterator` if we need to restore a `close` callable from the
# original return value.
else:
while not response:
buffer.append(next(app_iter))
if buffer:
app_iter = chain(buffer, app_iter)
if close_func is not None and app_iter is not app_rv:
app_iter = ClosingIterator(app_iter, close_func)
return app_iter, response[0], Headers(response[1])
def __init__(
self, response=None, status=None, headers=None,
mimetype=None, content_type=None, direct_passthrough=False,
):
if isinstance(headers, Headers):
self.headers = headers
elif not headers:
self.headers = Headers()
else:
self.headers = Headers(headers)
if content_type is None:
if mimetype is None and 'content-type' not in self.headers:
mimetype = self.default_mimetype
if mimetype is not None:
mimetype = get_content_type(mimetype, self.charset)
content_type = mimetype
if content_type is not None:
self.headers['Content-Type'] = content_type
if status is None:
status = self.default_status
if isinstance(status, int):
self.status_code = status
else:
self.status = status
self.direct_passthrough = direct_passthrough
self._on_close = []
# we set the response after the headers so that if a class changes
# the charset attribute, the data is set in the correct charset.
if response is None:
self.response = []
elif isinstance(response, (str, bytes, bytearray)):
self.set_data(response)
else:
self.response = response
class BaseResponse(object):
"""Base response class. The most important fact about a response object
is that it's a regular WSGI application. It's initialized with a couple
of response parameters (headers, body, status code etc.) and will start a
valid WSGI response when called with the environ and start response
callable.
Because it's a WSGI application itself processing usually ends before the
actual response is sent to the server. This helps debugging systems
because they can catch all the exceptions before responses are started.
Here a small example WSGI application that takes advantage of the
response objects::
from verktyg.wrappers import BaseResponse as Response
def index():
return Response('Index page')
def application(environ, start_response):
path = environ.get('PATH_INFO') or '/'
if path == '/':
response = index()
else:
response = Response('Not Found', status=404)
return response(environ, start_response)
Like :class:`BaseRequest` which object is lacking a lot of functionality
implemented in mixins. This gives you a better control about the actual
API of your response objects, so you can create subclasses and add custom
functionality. A full featured response object is available as
:class:`Response` which implements a couple of useful mixins.
To enforce a new type of already existing responses you can use the
:meth:`force_type` method. This is useful if you're working with different
subclasses of response objects and you want to post process them with a
known interface.
Per default the request object will assume all the text data is `utf-8`
encoded. Please refer to `the unicode chapter <unicode.txt>`_ for more
details about customizing the behavior.
Response can be any kind of iterable or string. If it's a string it's
considered being an iterable with one item which is the string passed.
Headers can be a list of tuples or a :class:`~verktyg.http.Headers` object.
Special note for `mimetype` and `content_type`: For most mime types
`mimetype` and `content_type` work the same, the difference affects
only 'text' mimetypes. If the mimetype passed with `mimetype` is a
mimetype starting with `text/`, the charset parameter of the response
object is appended to it. In contrast the `content_type` parameter is
always added as header unmodified.
:param response: a string or response iterable.
:param status: a string with a status or an integer with the status code.
:param headers: a list of headers or a
:class:`~verktyg.http.Headers` object.
:param mimetype: the mimetype for the request. See notice above.
:param content_type: the content type for the request. See notice above.
:param direct_passthrough: if set to `True` :meth:`iter_encoded` is not
called before iteration which makes it
possible to pass special iterators through
unchanged (see :func:`wrap_file` for more
details.)
"""
#: the charset of the response.
charset = 'utf-8'
#: the default status if none is provided.
default_status = 200
#: the default mimetype if none is provided.
default_mimetype = 'text/plain'
#: if set to `False` accessing properties on the response object will
#: not try to consume the response iterator and convert it into a list.
implicit_sequence_conversion = True
#: Should this response object correct the location header to be RFC
#: conformant? This is true by default.
autocorrect_location_header = True
#: Should this response object automatically set the content-length
#: header if possible? This is true by default.
automatically_set_content_length = True
def __init__(self, response=None, status=None, headers=None,
mimetype=None, content_type=None, direct_passthrough=False):
if isinstance(headers, Headers):
self.headers = headers
elif not headers:
self.headers = Headers()
else:
self.headers = Headers(headers)
if content_type is None:
if mimetype is None and 'content-type' not in self.headers:
mimetype = self.default_mimetype
if mimetype is not None:
mimetype = get_content_type(mimetype, self.charset)
content_type = mimetype
if content_type is not None:
self.headers['Content-Type'] = content_type
if status is None:
status = self.default_status
if isinstance(status, int):
self.status_code = status
else:
self.status = status
self.direct_passthrough = direct_passthrough
self._on_close = []
# we set the response after the headers so that if a class changes
# the charset attribute, the data is set in the correct charset.
if response is None:
self.response = []
elif isinstance(response, (str, bytes, bytearray)):
self.set_data(response)
else:
self.response = response
def call_on_close(self, func):
"""Adds a function to the internal list of functions that should
be called as part of closing down the response. Since 0.7 this
function also returns the function that was passed so that this
can be used as a decorator.
"""
self._on_close.append(func)
return func
def __repr__(self):
if self.is_sequence:
body_info = '%d bytes' % sum(map(len, self.iter_encoded()))
else:
body_info = 'streamed' if self.is_streamed else 'likely-streamed'
return '<%s %s [%s]>' % (
self.__class__.__name__,
body_info,
self.status
)
@classmethod
def force_type(cls, response, environ=None):
"""Enforce that the WSGI response is a response object of the current
type. Werkzeug will use the :class:`BaseResponse` internally in many
situations like the exceptions. If you call :meth:`get_response` on an
exception you will get back a regular :class:`BaseResponse` object,
even if you are using a custom subclass.
This method can enforce a given response type, and it will also
convert arbitrary WSGI callables into response objects if an environ
is provided::
# convert a Werkzeug response object into an instance of the
# MyResponseClass subclass.
response = MyResponseClass.force_type(response)
# convert any WSGI application into a response object
response = MyResponseClass.force_type(response, environ)
This is especially useful if you want to post-process responses in
the main dispatcher and use functionality provided by your subclass.
Keep in mind that this will modify response objects in place if
possible!
:param response: a response object or wsgi application.
:param environ: a WSGI environment object.
:return: a response object.
"""
if not isinstance(response, BaseResponse):
if environ is None:
raise TypeError('cannot convert WSGI application into '
'response objects without an environ')
response = BaseResponse(*_run_wsgi_app(response, environ))
response.__class__ = cls
return response
@classmethod
def from_app(cls, app, environ, buffered=False):
"""Create a new response object from an application output. This
works best if you pass it an application that returns a generator all
the time. Sometimes applications may use the `write()` callable
returned by the `start_response` function. This tries to resolve such
edge cases automatically. But if you don't get the expected output
you should set `buffered` to `True` which enforces buffering.
:param app: the WSGI application to execute.
:param environ: the WSGI environment to execute against.
:param buffered: set to `True` to enforce buffering.
:return: a response object.
"""
return cls(*_run_wsgi_app(app, environ, buffered))
def _get_status_code(self):
return self._status_code
def _set_status_code(self, code):
self._status_code = code
try:
self._status = '%d %s' % (code, HTTP_STATUS_CODES[code].upper())
except KeyError:
self._status = '%d UNKNOWN' % code
status_code = property(_get_status_code, _set_status_code,
doc='The HTTP Status code as number')
del _get_status_code, _set_status_code
def _get_status(self):
return self._status
def _set_status(self, value):
self._status = value
try:
self._status_code = int(self._status.split(None, 1)[0])
except ValueError:
self._status_code = 0
self._status = '0 %s' % self._status
status = property(_get_status, _set_status, doc='The HTTP Status code')
del _get_status, _set_status
def get_data(self, as_text=False):
"""The string representation of the request body. Whenever you call
this property the request iterable is encoded and flattened. This
can lead to unwanted behavior if you stream big data.
This behavior can be disabled by setting
:attr:`implicit_sequence_conversion` to `False`.
If `as_text` is set to `True` the return value will be a decoded
unicode string.
"""
self._ensure_sequence()
rv = b''.join(self.iter_encoded())
if as_text:
rv = rv.decode(self.charset)
return rv
def set_data(self, value):
"""Sets a new string as response. The value set must either by a
unicode or bytestring. If a unicode string is set it's encoded
automatically to the charset of the response (utf-8 by default).
"""
# if an unicode string is set, it's encoded directly so that we
# can set the content length
if isinstance(value, str):
value = value.encode(self.charset)
else:
value = bytes(value)
self.response = [value]
if self.automatically_set_content_length:
self.headers['Content-Length'] = str(len(value))
def calculate_content_length(self):
"""Returns the content length if available or `None` otherwise."""
try:
self._ensure_sequence()
except RuntimeError:
return None
return sum(len(x) for x in self.response)
def _ensure_sequence(self, mutable=False):
"""This method can be called by methods that need a sequence. If
`mutable` is true, it will also ensure that the response sequence
is a standard Python list.
"""
if self.is_sequence:
# if we need a mutable object, we ensure it's a list.
if mutable and not isinstance(self.response, list):
self.response = list(self.response)
return
if self.direct_passthrough:
raise RuntimeError('Attempted implicit sequence conversion '
'but the response object is in direct '
'passthrough mode.')
if not self.implicit_sequence_conversion:
raise RuntimeError('The response object required the iterable '
'to be a sequence, but the implicit '
'conversion was disabled. Call '
'make_sequence() yourself.')
self.make_sequence()
def make_sequence(self):
"""Converts the response iterator in a list. By default this happens
automatically if required. If `implicit_sequence_conversion` is
disabled, this method is not automatically called and some properties
might raise exceptions. This also encodes all the items.
"""
if not self.is_sequence:
# if we consume an iterable we have to ensure that the close
# method of the iterable is called if available when we tear
# down the response
close = getattr(self.response, 'close', None)
self.response = list(self.iter_encoded())
if close is not None:
self.call_on_close(close)
def iter_encoded(self):
"""Iter the response encoded with the encoding of the response.
If the response object is invoked as WSGI application the return
value of this method is used as application iterator unless
:attr:`direct_passthrough` was activated.
"""
if __debug__:
_warn_if_string(self.response)
# Encode in a separate function so that self.response is fetched
# early. This allows us to wrap the response with the return
# value from get_app_iter or iter_encoded.
return _iter_encoded(self.response, self.charset)
def set_cookie(self, key, value='', max_age=None, expires=None,
path='/', domain=None, secure=None, httponly=False):
"""Sets a cookie. The parameters are the same as in the cookie `Morsel`
object in the Python standard library but it accepts unicode data, too.
:param key: the key (name) of the cookie to be set.
:param value: the value of the cookie.
:param max_age: should be a number of seconds, or `None` (default) if
the cookie should last only as long as the client's
browser session.
:param expires: should be a `datetime` object or UNIX timestamp.
:param domain: if you want to set a cross-domain cookie. For example,
``domain=".example.com"`` will set a cookie that is
readable by the domain ``www.example.com``,
``foo.example.com`` etc. Otherwise, a cookie will only
be readable by the domain that set it.
:param path: limits the cookie to a given path, per default it will
span the whole domain.
"""
self.headers.add(
'Set-Cookie', dump_cookie(
key, value, max_age, expires,
path, domain, secure, httponly,
self.charset
)
)
def delete_cookie(self, key, path='/', domain=None):
"""Delete a cookie. Fails silently if key doesn't exist.
:param key: the key (name) of the cookie to be deleted.
:param path: if the cookie that should be deleted was limited to a
path, the path has to be defined here.
:param domain: if the cookie that should be deleted was limited to a
domain, that domain has to be defined here.
"""
self.set_cookie(key, expires=0, max_age=0, path=path, domain=domain)
@property
def is_streamed(self):
"""If the response is streamed (the response is not an iterable with
a length information) this property is `True`. In this case streamed
means that there is no information about the number of iterations.
This is usually `True` if a generator is passed to the response object.
This is useful for checking before applying some sort of post
filtering that should not take place for streamed responses.
"""
try:
len(self.response)
except (TypeError, AttributeError):
return True
return False
@property
def is_sequence(self):
"""If the iterator is buffered, this property will be `True`. A
response object will consider an iterator to be buffered if the
response attribute is a list or tuple.
"""
return isinstance(self.response, (tuple, list))
def close(self):
"""Close the wrapped response if possible. You can also use the object
in a with statement which will automatically close it.
"""
if hasattr(self.response, 'close'):
self.response.close()
for func in self._on_close:
func()
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, tb):
self.close()
def freeze(self):
"""Call this method if you want to make your response object ready for
being pickled. This buffers the generator if there is one. It will
also set the `Content-Length` header to the length of the body.
"""
# we explicitly set the length to a list of the *encoded* response
# iterator. Even if the implicit sequence conversion is disabled.
self.response = list(self.iter_encoded())
self.headers['Content-Length'] = str(sum(map(len, self.response)))
def get_wsgi_headers(self, environ):
"""This is automatically called right before the response is started
and returns headers modified for the given environment. It returns a
copy of the headers from the response with some modifications applied
if necessary.
For example the location header (if present) is joined with the root
URL of the environment. Also the content length is automatically set
to zero here for certain status codes.
:param environ: the WSGI environment of the request.
:return: returns a new :class:`~verktyg.http.Headers`
object.
"""
headers = Headers(self.headers)
location = None
content_location = None
content_length = None
status = self.status_code
# iterate over the headers to find all values in one go. Because
# get_wsgi_headers is used each response that gives us a tiny
# speedup.
for key, value in headers:
ikey = key.lower()
if ikey == u'location':
location = value
elif ikey == u'content-location':
content_location = value
elif ikey == u'content-length':
content_length = value
# make sure the location header is an absolute URL
if location is not None:
old_location = location
if isinstance(location, str):
# Safe conversion is necessary here as we might redirect
# to a broken URI scheme (for instance itms-services).
location = iri_to_uri(location, safe_conversion=True)
if self.autocorrect_location_header:
current_url = get_current_url(environ, root_only=True)
if isinstance(current_url, str):
current_url = iri_to_uri(current_url)
location = urljoin(current_url, location)
if location != old_location:
headers['Location'] = location
# make sure the content location is a URL
if (
content_location is not None and
isinstance(content_location, str)
):
headers['Content-Location'] = iri_to_uri(content_location)
# remove entity headers and set content length to zero if needed.
# Also update content_length accordingly so that the automatic
# content length detection does not trigger in the following
# code.
if 100 <= status < 200 or status == 204:
headers['Content-Length'] = content_length = u'0'
elif status == 304:
remove_entity_headers(headers)
# if we can determine the content length automatically, we
# should try to do that. But only if this does not involve
# flattening the iterator or encoding of unicode strings in
# the response. We however should not do that if we have a 304
# response.
if (
self.automatically_set_content_length and
self.is_sequence and content_length is None and status != 304
):
try:
content_length = sum(len(to_bytes(x, 'ascii'))
for x in self.response)
except UnicodeError:
# aha, something non-bytestringy in there, too bad, we
# can't safely figure out the length of the response.
pass
else:
headers['Content-Length'] = str(content_length)
return headers
def get_app_iter(self, environ):
"""Returns the application iterator for the given environ. Depending
on the request method and the current status code the return value
might be an empty response rather than the one from the response.
If the request method is `HEAD` or the status code is in a range
where the HTTP specification requires an empty response, an empty
iterable is returned.
:param environ: the WSGI environment of the request.
:return: a response iterable.
"""
status = self.status_code
if (
environ['REQUEST_METHOD'] == 'HEAD' or
100 <= status < 200 or status in (204, 304)
):
iterable = ()
elif self.direct_passthrough:
if __debug__:
_warn_if_string(self.response)
return self.response
else:
iterable = self.iter_encoded()
return ClosingIterator(iterable, self.close)
def get_wsgi_response(self, environ):
"""Returns the final WSGI response as tuple. The first item in
the tuple is the application iterator, the second the status and
the third the list of headers. The response returned is created
specially for the given environment. For example if the request
method in the WSGI environment is ``'HEAD'`` the response will
be empty and only the headers and status code will be present.
:param environ: the WSGI environment of the request.
:return: an ``(app_iter, status, headers)`` tuple.
"""
headers = self.get_wsgi_headers(environ)
app_iter = self.get_app_iter(environ)
return app_iter, self.status, headers.to_wsgi_list()
def __call__(self, environ, start_response):
"""Process this response as WSGI application.
:param environ: the WSGI environment.
:param start_response: the response callable provided by the WSGI
server.
:return: an application iterator
"""
app_iter, status, headers = self.get_wsgi_response(environ)
start_response(status, headers)
return app_iter
def get_wsgi_headers(self, environ):
"""This is automatically called right before the response is started
and returns headers modified for the given environment. It returns a
copy of the headers from the response with some modifications applied
if necessary.
For example the location header (if present) is joined with the root
URL of the environment. Also the content length is automatically set
to zero here for certain status codes.
:param environ: the WSGI environment of the request.
:return: returns a new :class:`~verktyg.http.Headers`
object.
"""
headers = Headers(self.headers)
location = None
content_location = None
content_length = None
status = self.status_code
# iterate over the headers to find all values in one go. Because
# get_wsgi_headers is used each response that gives us a tiny
# speedup.
for key, value in headers:
ikey = key.lower()
if ikey == u'location':
location = value
elif ikey == u'content-location':
content_location = value
elif ikey == u'content-length':
content_length = value
# make sure the location header is an absolute URL
if location is not None:
old_location = location
if isinstance(location, str):
# Safe conversion is necessary here as we might redirect
# to a broken URI scheme (for instance itms-services).
location = iri_to_uri(location, safe_conversion=True)
if self.autocorrect_location_header:
current_url = get_current_url(environ, root_only=True)
if isinstance(current_url, str):
current_url = iri_to_uri(current_url)
location = urljoin(current_url, location)
if location != old_location:
headers['Location'] = location
# make sure the content location is a URL
if (
content_location is not None and
isinstance(content_location, str)
):
headers['Content-Location'] = iri_to_uri(content_location)
# remove entity headers and set content length to zero if needed.
# Also update content_length accordingly so that the automatic
# content length detection does not trigger in the following
# code.
if 100 <= status < 200 or status == 204:
headers['Content-Length'] = content_length = u'0'
elif status == 304:
remove_entity_headers(headers)
# if we can determine the content length automatically, we
# should try to do that. But only if this does not involve
# flattening the iterator or encoding of unicode strings in
# the response. We however should not do that if we have a 304
# response.
if (
self.automatically_set_content_length and
self.is_sequence and content_length is None and status != 304
):
try:
content_length = sum(len(to_bytes(x, 'ascii'))
for x in self.response)
except UnicodeError:
# aha, something non-bytestringy in there, too bad, we
# can't safely figure out the length of the response.
pass
else:
headers['Content-Length'] = str(content_length)
return headers
class BaseResponse(object):
"""Base response class. The most important fact about a response object
is that it's a regular WSGI application. It's initialized with a couple
of response parameters (headers, body, status code etc.) and will start a
valid WSGI response when called with the environ and start response
callable.
Because it's a WSGI application itself processing usually ends before the
actual response is sent to the server. This helps debugging systems
because they can catch all the exceptions before responses are started.
Here a small example WSGI application that takes advantage of the
response objects::
from verktyg.wrappers import BaseResponse as Response
def index():
return Response('Index page')
def application(environ, start_response):
path = environ.get('PATH_INFO') or '/'
if path == '/':
response = index()
else:
response = Response('Not Found', status=404)
return response(environ, start_response)
Like :class:`BaseRequest` which object is lacking a lot of functionality
implemented in mixins. This gives you a better control about the actual
API of your response objects, so you can create subclasses and add custom
functionality. A full featured response object is available as
:class:`Response` which implements a couple of useful mixins.
To enforce a new type of already existing responses you can use the
:meth:`force_type` method. This is useful if you're working with different
subclasses of response objects and you want to post process them with a
known interface.
Per default the request object will assume all the text data is `utf-8`
encoded. Please refer to `the unicode chapter <unicode.txt>`_ for more
details about customizing the behavior.
Response can be any kind of iterable or string. If it's a string it's
considered being an iterable with one item which is the string passed.
Headers can be a list of tuples or a :class:`~verktyg.http.Headers` object.
Special note for `mimetype` and `content_type`: For most mime types
`mimetype` and `content_type` work the same, the difference affects
only 'text' mimetypes. If the mimetype passed with `mimetype` is a
mimetype starting with `text/`, the charset parameter of the response
object is appended to it. In contrast the `content_type` parameter is
always added as header unmodified.
:param response:
A string or response iterable.
:param status:
A string with a status or an integer with the status code.
:param headers:
A list of headers or a :class:`~verktyg.http.Headers` object.
:param mimetype:
The mimetype for the request. See notice above.
:param content_type:
The content type for the request. See notice above.
:param direct_passthrough:
If set to `True` :meth:`iter_encoded` is not called before iteration
which makes it possible to pass special iterators through unchanged
(see :func:`wrap_file` for more details.)
"""
#: the charset of the response.
charset = 'utf-8'
#: the default status if none is provided.
default_status = 200
#: the default mimetype if none is provided.
default_mimetype = 'text/plain'
#: if set to `False` accessing properties on the response object will
#: not try to consume the response iterator and convert it into a list.
implicit_sequence_conversion = True
#: Should this response object correct the location header to be RFC
#: conformant? This is true by default.
autocorrect_location_header = True
#: Should this response object automatically set the content-length
#: header if possible? This is true by default.
automatically_set_content_length = True
def __init__(
self, response=None, status=None, headers=None,
mimetype=None, content_type=None, direct_passthrough=False,
):
if isinstance(headers, Headers):
self.headers = headers
elif not headers:
self.headers = Headers()
else:
self.headers = Headers(headers)
if content_type is None:
if mimetype is None and 'content-type' not in self.headers:
mimetype = self.default_mimetype
if mimetype is not None:
mimetype = get_content_type(mimetype, self.charset)
content_type = mimetype
if content_type is not None:
self.headers['Content-Type'] = content_type
if status is None:
status = self.default_status
if isinstance(status, int):
self.status_code = status
else:
self.status = status
self.direct_passthrough = direct_passthrough
self._on_close = []
# we set the response after the headers so that if a class changes
# the charset attribute, the data is set in the correct charset.
if response is None:
self.response = []
elif isinstance(response, (str, bytes, bytearray)):
self.set_data(response)
else:
self.response = response
def call_on_close(self, func):
"""Adds a function to the internal list of functions that should
be called as part of closing down the response. Since 0.7 this
function also returns the function that was passed so that this
can be used as a decorator.
"""
self._on_close.append(func)
return func
def __repr__(self):
if self.is_sequence:
body_info = '%d bytes' % sum(map(len, self.iter_encoded()))
else:
body_info = 'streamed' if self.is_streamed else 'likely-streamed'
return '<%s %s [%s]>' % (
self.__class__.__name__,
body_info,
self.status
)
@classmethod
def force_type(cls, response, environ=None):
"""Enforce that the WSGI response is a response object of the current
type. Werkzeug will use the :class:`BaseResponse` internally in many
situations like the exceptions. If you call :meth:`get_response` on an
exception you will get back a regular :class:`BaseResponse` object,
even if you are using a custom subclass.
This method can enforce a given response type, and it will also
convert arbitrary WSGI callables into response objects if an environ
is provided::
# convert a Werkzeug response object into an instance of the
# MyResponseClass subclass.
response = MyResponseClass.force_type(response)
# convert any WSGI application into a response object
response = MyResponseClass.force_type(response, environ)
This is especially useful if you want to post-process responses in
the main dispatcher and use functionality provided by your subclass.
Keep in mind that this will modify response objects in place if
possible!
:param response:
A response object or wsgi application.
:param environ:
A WSGI environment object.
:return:
A response object.
"""
if not isinstance(response, BaseResponse):
if environ is None:
raise TypeError(
'cannot convert WSGI application into '
'response objects without an environ'
)
response = BaseResponse(*_run_wsgi_app(response, environ))
response.__class__ = cls
return response
@classmethod
def from_app(cls, app, environ, buffered=False):
"""Create a new response object from an application output. This
works best if you pass it an application that returns a generator all
the time. Sometimes applications may use the `write()` callable
returned by the `start_response` function. This tries to resolve such
edge cases automatically. But if you don't get the expected output
you should set `buffered` to `True` which enforces buffering.
:param app:
The WSGI application to execute.
:param environ:
The WSGI environment to execute against.
:param buffered:
Set to `True` to enforce buffering.
:return:
A response object.
"""
return cls(*_run_wsgi_app(app, environ, buffered))
def _get_status_code(self):
return self._status_code
def _set_status_code(self, code):
self._status_code = code
try:
self._status = '%d %s' % (code, HTTP_STATUS_CODES[code].upper())
except KeyError:
self._status = '%d UNKNOWN' % code
status_code = property(
_get_status_code, _set_status_code,
doc='The HTTP Status code as number',
)
del _get_status_code, _set_status_code
def _get_status(self):
return self._status
def _set_status(self, value):
self._status = value
try:
self._status_code = int(self._status.split(None, 1)[0])
except ValueError:
self._status_code = 0
self._status = '0 %s' % self._status
status = property(_get_status, _set_status, doc='The HTTP Status code')
del _get_status, _set_status
def get_data(self, as_text=False):
"""The string representation of the request body. Whenever you call
this property the request iterable is encoded and flattened. This
can lead to unwanted behavior if you stream big data.
This behavior can be disabled by setting
:attr:`implicit_sequence_conversion` to `False`.
If `as_text` is set to `True` the return value will be a decoded
unicode string.
"""
self._ensure_sequence()
rv = b''.join(self.iter_encoded())
if as_text:
rv = rv.decode(self.charset)
return rv
def set_data(self, value):
"""Sets a new string as response. The value set must either by a
unicode or bytestring. If a unicode string is set it's encoded
automatically to the charset of the response (utf-8 by default).
"""
# if an unicode string is set, it's encoded directly so that we
# can set the content length
if isinstance(value, str):
value = value.encode(self.charset)
else:
value = bytes(value)
self.response = [value]
if self.automatically_set_content_length:
self.headers['Content-Length'] = str(len(value))
def calculate_content_length(self):
"""Returns the content length if available or `None` otherwise."""
try:
self._ensure_sequence()
except RuntimeError:
return None
return sum(len(x) for x in self.response)
def _ensure_sequence(self, mutable=False):
"""This method can be called by methods that need a sequence. If
`mutable` is true, it will also ensure that the response sequence
is a standard Python list.
"""
if self.is_sequence:
# if we need a mutable object, we ensure it's a list.
if mutable and not isinstance(self.response, list):
self.response = list(self.response)
return
if self.direct_passthrough:
raise RuntimeError(
'Attempted implicit sequence conversion but the response '
'object is in direct passthrough mode.'
)
if not self.implicit_sequence_conversion:
raise RuntimeError(
'The response object required the iterable to be a sequence, '
'but the implicit conversion was disabled. Call '
'make_sequence() yourself.'
)
self.make_sequence()
def make_sequence(self):
"""Converts the response iterator in a list. By default this happens
automatically if required. If `implicit_sequence_conversion` is
disabled, this method is not automatically called and some properties
might raise exceptions. This also encodes all the items.
"""
if not self.is_sequence:
# if we consume an iterable we have to ensure that the close
# method of the iterable is called if available when we tear
# down the response
close = getattr(self.response, 'close', None)
self.response = list(self.iter_encoded())
if close is not None:
self.call_on_close(close)
def iter_encoded(self):
"""Iter the response encoded with the encoding of the response.
If the response object is invoked as WSGI application the return
value of this method is used as application iterator unless
:attr:`direct_passthrough` was activated.
"""
if __debug__:
_warn_if_string(self.response)
# Encode in a separate function so that self.response is fetched
# early. This allows us to wrap the response with the return
# value from get_app_iter or iter_encoded.
return _iter_encoded(self.response, self.charset)
def set_cookie(
self, key, value='', max_age=None, expires=None,
path='/', domain=None, secure=None, httponly=False,
):
"""Sets a cookie. The parameters are the same as in the cookie `Morsel`
object in the Python standard library but it accepts unicode data, too.
:param key:
The key (name) of the cookie to be set.
:param value:
The value of the cookie.
:param max_age:
Should be a number of seconds, or `None` (default) if the cookie
should last only as long as the client's browser session.
:param expires:
Should be a `datetime` object or UNIX timestamp.
:param domain:
If you want to set a cross-domain cookie. For example,
``domain=".example.com"`` will set a cookie that is readable by the
domain ``www.example.com``, ``foo.example.com`` etc. Otherwise, a
cookie will only be readable by the domain that set it.
:param path:
Limits the cookie to a given path, per default it will span the
whole domain.
"""
self.headers.add(
'Set-Cookie', dump_cookie(
key, value, max_age, expires,
path, domain, secure, httponly,
self.charset
)
)
def delete_cookie(self, key, path='/', domain=None):
"""Delete a cookie. Fails silently if key doesn't exist.
:param key:
The key (name) of the cookie to be deleted.
:param path:
If the cookie that should be deleted was limited to a path, the
path has to be defined here.
:param domain:
If the cookie that should be deleted was limited to a domain, that
domain has to be defined here.
"""
self.set_cookie(key, expires=0, max_age=0, path=path, domain=domain)
@property
def is_streamed(self):
"""If the response is streamed (the response is not an iterable with
a length information) this property is `True`. In this case streamed
means that there is no information about the number of iterations.
This is usually `True` if a generator is passed to the response object.
This is useful for checking before applying some sort of post
filtering that should not take place for streamed responses.
"""
try:
len(self.response)
except (TypeError, AttributeError):
return True
return False
@property
def is_sequence(self):
"""If the iterator is buffered, this property will be `True`. A
response object will consider an iterator to be buffered if the
response attribute is a list or tuple.
"""
return isinstance(self.response, (tuple, list))
def close(self):
"""Close the wrapped response if possible. You can also use the object
in a with statement which will automatically close it.
"""
if hasattr(self.response, 'close'):
self.response.close()
for func in self._on_close:
func()
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, tb):
self.close()
def freeze(self):
"""Call this method if you want to make your response object ready for
being pickled. This buffers the generator if there is one. It will
also set the `Content-Length` header to the length of the body.
"""
# we explicitly set the length to a list of the *encoded* response
# iterator. Even if the implicit sequence conversion is disabled.
self.response = list(self.iter_encoded())
self.headers['Content-Length'] = str(sum(map(len, self.response)))
def get_wsgi_headers(self, environ):
"""This is automatically called right before the response is started
and returns headers modified for the given environment. It returns a
copy of the headers from the response with some modifications applied
if necessary.
For example the location header (if present) is joined with the root
URL of the environment. Also the content length is automatically set
to zero here for certain status codes.
:param environ:
The WSGI environment of the request.
:return:
Returns a new :class:`~verktyg.http.Headers` object.
"""
headers = Headers(self.headers)
location = None
content_location = None
content_length = None
status = self.status_code
# iterate over the headers to find all values in one go. Because
# get_wsgi_headers is used each response that gives us a tiny
# speedup.
for key, value in headers:
ikey = key.lower()
if ikey == u'location':
location = value
elif ikey == u'content-location':
content_location = value
elif ikey == u'content-length':
content_length = value
# make sure the location header is an absolute URL
if location is not None:
old_location = location
if isinstance(location, str):
# Safe conversion is necessary here as we might redirect
# to a broken URI scheme (for instance itms-services).
location = iri_to_uri(location)
if self.autocorrect_location_header:
current_url = get_current_url(environ, root_only=True)
if isinstance(current_url, str):
current_url = iri_to_uri(current_url)
location = urljoin(current_url, location)
if location != old_location:
headers['Location'] = location
# make sure the content location is a URL
if (
content_location is not None and
isinstance(content_location, str)
):
headers['Content-Location'] = iri_to_uri(content_location)
# remove entity headers and set content length to zero if needed.
# Also update content_length accordingly so that the automatic
# content length detection does not trigger in the following
# code.
if 100 <= status < 200 or status == 204:
headers['Content-Length'] = content_length = u'0'
elif status == 304:
remove_entity_headers(headers)
# if we can determine the content length automatically, we
# should try to do that. But only if this does not involve
# flattening the iterator or encoding of unicode strings in
# the response. We however should not do that if we have a 304
# response.
if (
self.automatically_set_content_length and
self.is_sequence and content_length is None and status != 304
):
content_length = sum(len(x) for x in self.response)
headers['Content-Length'] = str(content_length)
return headers
def get_app_iter(self, environ):
"""Returns the application iterator for the given environ. Depending
on the request method and the current status code the return value
might be an empty response rather than the one from the response.
If the request method is `HEAD` or the status code is in a range
where the HTTP specification requires an empty response, an empty
iterable is returned.
:param environ:
The WSGI environment of the request.
:return:
A response iterable.
"""
status = self.status_code
if (
environ['REQUEST_METHOD'] == 'HEAD' or
100 <= status < 200 or status in (204, 304)
):
iterable = ()
elif self.direct_passthrough:
if __debug__:
_warn_if_string(self.response)
return self.response
else:
iterable = self.iter_encoded()
return ClosingIterator(iterable, self.close)
def get_wsgi_response(self, environ):
"""Returns the final WSGI response as tuple. The first item in
the tuple is the application iterator, the second the status and
the third the list of headers. The response returned is created
specially for the given environment. For example if the request
method in the WSGI environment is ``'HEAD'`` the response will
be empty and only the headers and status code will be present.
:param environ:
The WSGI environment of the request.
:return:
An ``(app_iter, status, headers)`` tuple.
"""
headers = self.get_wsgi_headers(environ)
app_iter = self.get_app_iter(environ)
return app_iter, self.status, headers.to_wsgi_list()
def __call__(self, environ, start_response):
"""Process this response as WSGI application.
:param environ:
The WSGI environment.
:param start_response:
The response callable provided by the WSGI server.
:return:
An application iterator
"""
app_iter, status, headers = self.get_wsgi_response(environ)
start_response(status, headers)
return app_iter
def test_response_headers_passthrough(self):
headers = Headers()
resp = Response(headers=headers)
self.assertIs(resp.headers, headers)