########################################################################
# File name: service.py
# This file is part of: aioxmpp
#
# LICENSE
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program. If not, see
# <http://www.gnu.org/licenses/>.
#
########################################################################
import asyncio
import contextlib
import weakref
import aioxmpp
import aioxmpp.service as service
import aioxmpp.callbacks as callbacks
class PEPClient(service.Service):
"""
:class:`PEPClient` simplifies working with PEP services.
Compared to :class:`~aioxmpp.PubSubClient` it supports automatic
checking for server support, a stream-lined API. It is intended to
make PEP things easy. If you need more fine-grained control or do
things which are not usually handled by the defaults when using PEP, use
:class:`~aioxmpp.PubSubClient` directly.
See :class:`register_pep_node` for the high-level interface for
claiming a PEP node and receiving event notifications.
There also is a low-level interface for claiming nodes:
.. automethod:: is_claimed
.. automethod:: claim_pep_node
Further we have a convenience method for publishing items in the client's
PEP service:
.. automethod:: publish
Use the :class:`aioxmpp.PubSubClient` For explicit subscription
and unsubscription .
"""
ORDER_AFTER = [
aioxmpp.DiscoClient,
aioxmpp.DiscoServer,
aioxmpp.PubSubClient,
]
def __init__(self, client, **kwargs):
super().__init__(client, **kwargs)
self._pubsub = self.dependencies[aioxmpp.PubSubClient]
self._disco_client = self.dependencies[aioxmpp.DiscoClient]
self._disco_server = self.dependencies[aioxmpp.DiscoServer]
self._pep_node_claims = weakref.WeakValueDictionary()
def is_claimed(self, node):
"""
Return whether `node` is claimed.
"""
return node in self._pep_node_claims
def claim_pep_node(self, node_namespace, *,
register_feature=True, notify=False):
"""
Claim node `node_namespace`.
:param node_namespace: the pubsub node whose events shall be
handled.
:param register_feature: Whether to publish the `node_namespace`
as feature.
:param notify: Whether to register the ``+notify`` feature to
receive notification without explicit subscription.
:raises RuntimeError: if a handler for `node_namespace` is already
set.
:returns: a :class:`~aioxmpp.pep.service.RegisteredPEPNode` instance
representing the claim.
.. seealso::
:class:`aioxmpp.pep.register_pep_node`
a descriptor which can be used with
:class:`~aioxmpp.service.Service` subclasses to claim a PEP node
automatically.
This registers `node_namespace` as feature for service discovery
unless ``register_feature=False`` is passed.
.. note::
For `notify` to work, it is required that
:class:`aioxmpp.EntityCapsService` is loaded and that presence is
re-sent soon after
:meth:`~aioxmpp.EntityCapsService.on_ver_changed` fires. See the
documentation of the class and the signal for details.
"""
if node_namespace in self._pep_node_claims:
raise RuntimeError(
"claiming already claimed node"
)
registered_node = RegisteredPEPNode(
self,
node_namespace,
register_feature=register_feature,
notify=notify,
)
finalizer = weakref.finalize(
registered_node,
weakref.WeakMethod(registered_node._unregister)
)
# we cannot guarantee that disco is not cleared up already,
# so we do not unclaim the feature on exit
finalizer.atexit = False
self._pep_node_claims[node_namespace] = registered_node
return registered_node
def _unclaim(self, node_namespace):
self._pep_node_claims.pop(node_namespace)
@asyncio.coroutine
def _check_for_pep(self):
# XXX: should this be done when the stream connects
# and we use the cached result later on (i.e. disable
# the PEP service if the server does not support PEP)
disco_info = yield from self._disco_client.query_info(
self.client.local_jid.bare()
)
for item in disco_info.identities.filter(attrs={"category": "pubsub"}):
if item.type_ == "pep":
break
else:
raise RuntimeError("server does not support PEP")
@service.depsignal(aioxmpp.PubSubClient, "on_item_published")
def _handle_pubsub_publish(self, jid, node, item, *, message=None):
try:
registered_node = self._pep_node_claims[node]
except KeyError:
return
# PEP requires, that notifies contain the data and that
# the namespace of the payload corresponds to the node,
# by enforcing this here we protect the consumers of
# the signal.
if (item.registered_payload is None or
item.registered_payload.TAG[0] != node):
self.logger.debug(
"ignoring notify from misconfigured PEP node %s at %s",
node, jid)
return
registered_node.on_item_publish(jid, node, item, message=message)
def publish(self, node, data, *, id_=None):
"""
Publish an item `data` in the PubSub node `node` on the
PEP service associated with the user's JID.
:param node: The PubSub node to publish to.
:param data: The item to publish.
:type data: An XSO representing the paylaod.
:param id_: The id the published item shall have.
:returns: The PubSub id of the published item or
:data:`None` if it is unknown.
:raises RuntimeError: if PEP is not supported.
If no `id_` is given it is generated by the server (and may be
returned).
"""
yield from self._check_for_pep()
return (yield from self._pubsub.publish(None, node, data, id_=id_))
[docs]class RegisteredPEPNode:
"""
Handle for registered PEP nodes.
*Never* instanciate this class yourself. Use
:class:`~aioxmpp.pep.register_pep_node` or
:attr:`~aioxmpp.pep.PEPClient.claim_pep_node` to obtain instances.
You have to keep a reference to the instance to
uphold the claim, when a instance is garbage
collected it is closed automatically. It is not enough to have a
callback registered! It is strongly recommended to explicitly
close the registered node if it is no longer needed or to use the
:class:`~aioxmpp.pep.register_pep_node` descriptor for automatic
life-cycle handling.
.. signal:: on_item_publish(jid, node, item, message=None)
Fires when an event is received for this PEP node. The arguments
are as for :attr:`aioxmpp.PubSubClient.on_item_publish`.
.. warning:: Empty notifications and notifications whose
payload namespace does not match the node
namespace are filtered and will not cause
this signal to fire (since they do not match the
PEP specification).
.. autoattribute:: notify
.. autoattribute:: feature_registered
.. automethod:: close
"""
def __init__(self, pep_service, node, register_feature, notify):
self._pep_service = pep_service
self._node = node
self._feature_registered = register_feature
self._notify = notify
self._closed = False
if self._feature_registered:
self._register_feature()
if self._notify:
self._register_notify()
on_item_publish = callbacks.Signal()
def _register_feature(self):
self._pep_service._disco_server.register_feature(self._node)
self._feature_registered = True
def _unregister_feature(self):
self._pep_service._disco_server.unregister_feature(self._node)
self._feature_registered = False
def _register_notify(self):
self._pep_service._disco_server.register_feature(self._notify_feature)
self._notify = True
def _unregister_notify(self):
self._pep_service._disco_server.unregister_feature(
self._notify_feature)
self._notify = False
def _unregister(self):
if self._notify:
self._unregister_notify()
if self._feature_registered:
self._unregister_feature()
[docs] def close(self):
"""
Unclaim the PEP node and unregister the registered features.
It is not necessary to call close if this claim is managed by
:class:`~aioxmpp.pep.register_pep_node`.
"""
if self._closed:
return
self._closed = True
self._pep_service._unclaim(self.node_namespace)
self._unregister()
@property
def node_namespace(self):
"""The claimed node namespace"""
return self._node
@property
def _notify_feature(self):
return self._node + "+notify"
@property
def notify(self):
"""
Whether we have enabled the ``+notify`` feature to automatically
receive notifications.
When setting this property the feature is registered and
unregistered appropriately.
.. note::
For `notify` to work, it is required that
:class:`aioxmpp.EntityCapsService` is loaded and that presence is
re-sent soon after
:meth:`~aioxmpp.EntityCapsService.on_ver_changed` fires. See the
documentation of the class and the signal for details.
"""
return self._notify
@notify.setter
[docs] def notify(self, value):
if self._closed:
raise RuntimeError(
"modifying a closed RegisteredPEPNode is forbidden"
)
# XXX: do we want to do strict type checking here?
if bool(value) == bool(self._notify):
return
if self._notify:
self._unregister_notify()
else:
self._register_notify()
@property
def feature_registered(self):
"""
Whether we have registered the node namespace as feature.
When setting this property the feature is registered and
unregistered appropriately.
"""
return self._feature_registered
@feature_registered.setter
[docs] def feature_registered(self, value):
if self._closed:
raise RuntimeError(
"modifying a closed RegisteredPEPNode is forbidden"
)
# XXX: do we want to do strict type checking here?
if bool(value) == bool(self._feature_registered):
return
if self._feature_registered:
self._unregister_feature()
else:
self._register_feature()
class register_pep_node(service.Descriptor):
"""
Service descriptor claiming a PEP node.
:param node_namespace: The PubSub payload namespace to handle.
:param register_feature: Whether to register the node namespace as feature.
:param notify: Whether to register for notifications.
If `notify` is :data:`True` it registers a ``+notify`` feature,
for automatic pubsub subscription.
The value of the descriptor on an instance is the
:class:`~aioxmpp.pep.service.RegisteredPEPNode` object representing the
claim.
"""
def __init__(self, node_namespace, *, register_feature=True,
notify=False):
super().__init__()
self._node_namespace = node_namespace
self._notify = notify
self._register_feature = register_feature
@property
def node_namespace(self):
"""
The node namespace to request notifications for.
"""
return self._node_namespace
@property
def register_feature(self):
"""
Whether we register the node namespace as feature.
"""
return self._register_feature
@property
def notify(self):
"""
Wether we register the ``+nofity`` feature.
"""
return self._notify
@property
def required_dependencies(self):
return [PEPClient]
@contextlib.contextmanager
def init_cm(self, instance):
pep_client = instance.dependencies[PEPClient]
claim = pep_client.claim_pep_node(
self._node_namespace,
register_feature=self._register_feature,
notify=self._notify,
)
yield claim
claim.close()
@property
def value_type(self):
return RegisteredPEPNode