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Diffstat (limited to 'slixmpp/plugins/xep_0050/adhoc.py')
| -rw-r--r-- | slixmpp/plugins/xep_0050/adhoc.py | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/slixmpp/plugins/xep_0050/adhoc.py b/slixmpp/plugins/xep_0050/adhoc.py new file mode 100644 index 00000000..fa6017d5 --- /dev/null +++ b/slixmpp/plugins/xep_0050/adhoc.py @@ -0,0 +1,665 @@ +""" + Slixmpp: The Slick XMPP Library + Copyright (C) 2011 Nathanael C. Fritz, Lance J.T. Stout + This file is part of Slixmpp. + + See the file LICENSE for copying permission. +""" + +import logging +import time + +from slixmpp import Iq +from slixmpp.exceptions import XMPPError +from slixmpp.xmlstream.handler import Callback +from slixmpp.xmlstream.matcher import StanzaPath +from slixmpp.xmlstream import register_stanza_plugin, JID +from slixmpp.plugins import BasePlugin +from slixmpp.plugins.xep_0050 import stanza +from slixmpp.plugins.xep_0050 import Command +from slixmpp.plugins.xep_0004 import Form + + +log = logging.getLogger(__name__) + + +class XEP_0050(BasePlugin): + + """ + XEP-0050: Ad-Hoc Commands + + XMPP's Adhoc Commands provides a generic workflow mechanism for + interacting with applications. The result is similar to menu selections + and multi-step dialogs in normal desktop applications. Clients do not + need to know in advance what commands are provided by any particular + application or agent. While adhoc commands provide similar functionality + to Jabber-RPC, adhoc commands are used primarily for human interaction. + + Also see <http://xmpp.org/extensions/xep-0050.html> + + Events: + command_execute -- Received a command with action="execute" + command_next -- Received a command with action="next" + command_complete -- Received a command with action="complete" + command_cancel -- Received a command with action="cancel" + + Attributes: + commands -- A dictionary mapping JID/node pairs to command + names and handlers. + sessions -- A dictionary or equivalent backend mapping + session IDs to dictionaries containing data + relevant to a command's session. + + Methods: + plugin_init -- Overrides BasePlugin.plugin_init + post_init -- Overrides BasePlugin.post_init + new_session -- Return a new session ID. + prep_handlers -- Placeholder. May call with a list of handlers + to prepare them for use with the session storage + backend, if needed. + set_backend -- Replace the default session storage with some + external storage mechanism, such as a database. + The provided backend wrapper must be able to + act using the same syntax as a dictionary. + add_command -- Add a command for use by external entitites. + get_commands -- Retrieve a list of commands provided by a + remote agent. + send_command -- Send a command request to a remote agent. + start_command -- Command user API: initiate a command session + continue_command -- Command user API: proceed to the next step + cancel_command -- Command user API: cancel a command + complete_command -- Command user API: finish a command + terminate_command -- Command user API: delete a command's session + """ + + name = 'xep_0050' + description = 'XEP-0050: Ad-Hoc Commands' + dependencies = set(['xep_0030', 'xep_0004']) + stanza = stanza + default_config = { + 'session_db': None + } + + def plugin_init(self): + """Start the XEP-0050 plugin.""" + self.sessions = self.session_db + if self.sessions is None: + self.sessions = {} + + self.commands = {} + + self.xmpp.register_handler( + Callback("Ad-Hoc Execute", + StanzaPath('iq@type=set/command'), + self._handle_command)) + + register_stanza_plugin(Iq, Command) + register_stanza_plugin(Command, Form, iterable=True) + + self.xmpp.add_event_handler('command_execute', + self._handle_command_start) + self.xmpp.add_event_handler('command_next', + self._handle_command_next) + self.xmpp.add_event_handler('command_cancel', + self._handle_command_cancel) + self.xmpp.add_event_handler('command_complete', + self._handle_command_complete) + + def plugin_end(self): + self.xmpp.del_event_handler('command_execute', + self._handle_command_start) + self.xmpp.del_event_handler('command_next', + self._handle_command_next) + self.xmpp.del_event_handler('command_cancel', + self._handle_command_cancel) + self.xmpp.del_event_handler('command_complete', + self._handle_command_complete) + self.xmpp.remove_handler('Ad-Hoc Execute') + self.xmpp['xep_0030'].del_feature(feature=Command.namespace) + self.xmpp['xep_0030'].set_items(node=Command.namespace, items=tuple()) + + def session_bind(self, jid): + self.xmpp['xep_0030'].add_feature(Command.namespace) + self.xmpp['xep_0030'].set_items(node=Command.namespace, items=tuple()) + + def set_backend(self, db): + """ + Replace the default session storage dictionary with + a generic, external data storage mechanism. + + The replacement backend must be able to interact through + the same syntax and interfaces as a normal dictionary. + + Arguments: + db -- The new session storage mechanism. + """ + self.sessions = db + + def prep_handlers(self, handlers, **kwargs): + """ + Prepare a list of functions for use by the backend service. + + Intended to be replaced by the backend service as needed. + + Arguments: + handlers -- A list of function pointers + **kwargs -- Any additional parameters required by the backend. + """ + pass + + # ================================================================= + # Server side (command provider) API + + def add_command(self, jid=None, node=None, name='', handler=None): + """ + Make a new command available to external entities. + + Access control may be implemented in the provided handler. + + Command workflow is done across a sequence of command handlers. The + first handler is given the initial Iq stanza of the request in order + to support access control. Subsequent handlers are given only the + payload items of the command. All handlers will receive the command's + session data. + + Arguments: + jid -- The JID that will expose the command. + node -- The node associated with the command. + name -- A human readable name for the command. + handler -- A function that will generate the response to the + initial command request, as well as enforcing any + access control policies. + """ + if jid is None: + jid = self.xmpp.boundjid + elif not isinstance(jid, JID): + jid = JID(jid) + item_jid = jid.full + + self.xmpp['xep_0030'].add_identity(category='automation', + itype='command-list', + name='Ad-Hoc commands', + node=Command.namespace, + jid=jid) + self.xmpp['xep_0030'].add_item(jid=item_jid, + name=name, + node=Command.namespace, + subnode=node, + ijid=jid) + self.xmpp['xep_0030'].add_identity(category='automation', + itype='command-node', + name=name, + node=node, + jid=jid) + self.xmpp['xep_0030'].add_feature(Command.namespace, None, jid) + + self.commands[(item_jid, node)] = (name, handler) + + def new_session(self): + """Return a new session ID.""" + return str(time.time()) + '-' + self.xmpp.new_id() + + def _handle_command(self, iq): + """Raise command events based on the command action.""" + self.xmpp.event('command_%s' % iq['command']['action'], iq) + + def _handle_command_start(self, iq): + """ + Process an initial request to execute a command. + + Arguments: + iq -- The command execution request. + """ + sessionid = self.new_session() + node = iq['command']['node'] + key = (iq['to'].full, node) + name, handler = self.commands.get(key, ('Not found', None)) + if not handler: + log.debug('Command not found: %s, %s', key, self.commands) + raise XMPPError('item-not-found') + + payload = [] + for stanza in iq['command']['substanzas']: + payload.append(stanza) + + if len(payload) == 1: + payload = payload[0] + + interfaces = set([item.plugin_attrib for item in payload]) + payload_classes = set([item.__class__ for item in payload]) + + initial_session = {'id': sessionid, + 'from': iq['from'], + 'to': iq['to'], + 'node': node, + 'payload': payload, + 'interfaces': interfaces, + 'payload_classes': payload_classes, + 'notes': None, + 'has_next': False, + 'allow_complete': False, + 'allow_prev': False, + 'past': [], + 'next': None, + 'prev': None, + 'cancel': None} + + session = handler(iq, initial_session) + + self._process_command_response(iq, session) + + def _handle_command_next(self, iq): + """ + Process a request for the next step in the workflow + for a command with multiple steps. + + Arguments: + iq -- The command continuation request. + """ + sessionid = iq['command']['sessionid'] + session = self.sessions.get(sessionid) + + if session: + handler = session['next'] + interfaces = session['interfaces'] + results = [] + for stanza in iq['command']['substanzas']: + if stanza.plugin_attrib in interfaces: + results.append(stanza) + if len(results) == 1: + results = results[0] + + session = handler(results, session) + + self._process_command_response(iq, session) + else: + raise XMPPError('item-not-found') + + def _handle_command_prev(self, iq): + """ + Process a request for the prev step in the workflow + for a command with multiple steps. + + Arguments: + iq -- The command continuation request. + """ + sessionid = iq['command']['sessionid'] + session = self.sessions.get(sessionid) + + if session: + handler = session['prev'] + interfaces = session['interfaces'] + results = [] + for stanza in iq['command']['substanzas']: + if stanza.plugin_attrib in interfaces: + results.append(stanza) + if len(results) == 1: + results = results[0] + + session = handler(results, session) + + self._process_command_response(iq, session) + else: + raise XMPPError('item-not-found') + + def _process_command_response(self, iq, session): + """ + Generate a command reply stanza based on the + provided session data. + + Arguments: + iq -- The command request stanza. + session -- A dictionary of relevant session data. + """ + sessionid = session['id'] + + payload = session['payload'] + if payload is None: + payload = [] + if not isinstance(payload, list): + payload = [payload] + + interfaces = session.get('interfaces', set()) + payload_classes = session.get('payload_classes', set()) + + interfaces.update(set([item.plugin_attrib for item in payload])) + payload_classes.update(set([item.__class__ for item in payload])) + + session['interfaces'] = interfaces + session['payload_classes'] = payload_classes + + self.sessions[sessionid] = session + + for item in payload: + register_stanza_plugin(Command, item.__class__, iterable=True) + + iq = iq.reply() + iq['command']['node'] = session['node'] + iq['command']['sessionid'] = session['id'] + + if session['next'] is None: + iq['command']['actions'] = [] + iq['command']['status'] = 'completed' + elif session['has_next']: + actions = ['next'] + if session['allow_complete']: + actions.append('complete') + if session['allow_prev']: + actions.append('prev') + iq['command']['actions'] = actions + iq['command']['status'] = 'executing' + else: + iq['command']['actions'] = ['complete'] + iq['command']['status'] = 'executing' + + iq['command']['notes'] = session['notes'] + + for item in payload: + iq['command'].append(item) + + iq.send() + + def _handle_command_cancel(self, iq): + """ + Process a request to cancel a command's execution. + + Arguments: + iq -- The command cancellation request. + """ + node = iq['command']['node'] + sessionid = iq['command']['sessionid'] + + session = self.sessions.get(sessionid) + + if session: + handler = session['cancel'] + if handler: + handler(iq, session) + del self.sessions[sessionid] + iq = iq.reply() + iq['command']['node'] = node + iq['command']['sessionid'] = sessionid + iq['command']['status'] = 'canceled' + iq['command']['notes'] = session['notes'] + iq.send() + else: + raise XMPPError('item-not-found') + + + def _handle_command_complete(self, iq): + """ + Process a request to finish the execution of command + and terminate the workflow. + + All data related to the command session will be removed. + + Arguments: + iq -- The command completion request. + """ + node = iq['command']['node'] + sessionid = iq['command']['sessionid'] + session = self.sessions.get(sessionid) + + if session: + handler = session['next'] + interfaces = session['interfaces'] + results = [] + for stanza in iq['command']['substanzas']: + if stanza.plugin_attrib in interfaces: + results.append(stanza) + if len(results) == 1: + results = results[0] + + if handler: + handler(results, session) + + del self.sessions[sessionid] + + payload = session['payload'] + if payload is None: + payload = [] + if not isinstance(payload, list): + payload = [payload] + + for item in payload: + register_stanza_plugin(Command, item.__class__, iterable=True) + + iq = iq.reply() + + iq['command']['node'] = node + iq['command']['sessionid'] = sessionid + iq['command']['actions'] = [] + iq['command']['status'] = 'completed' + iq['command']['notes'] = session['notes'] + + for item in payload: + iq['command'].append(item) + + iq.send() + else: + raise XMPPError('item-not-found') + + # ================================================================= + # Client side (command user) API + + def get_commands(self, jid, **kwargs): + """ + Return a list of commands provided by a given JID. + + Arguments: + jid -- The JID to query for commands. + local -- If true, then the query is for a JID/node + combination handled by this Slixmpp instance and + no stanzas need to be sent. + Otherwise, a disco stanza must be sent to the + remove JID to retrieve the items. + ifrom -- Specifiy the sender's JID. + timeout -- The time in seconds to block while waiting for + a reply. If None, then wait indefinitely. + callback -- Optional callback to execute when a reply is + received instead of blocking and waiting for + the reply. + iterator -- If True, return a result set iterator using + the XEP-0059 plugin, if the plugin is loaded. + Otherwise the parameter is ignored. + """ + return self.xmpp['xep_0030'].get_items(jid=jid, + node=Command.namespace, + **kwargs) + + def send_command(self, jid, node, ifrom=None, action='execute', + payload=None, sessionid=None, flow=False, **kwargs): + """ + Create and send a command stanza, without using the provided + workflow management APIs. + + Arguments: + jid -- The JID to send the command request or result. + node -- The node for the command. + ifrom -- Specify the sender's JID. + action -- May be one of: execute, cancel, complete, + or cancel. + payload -- Either a list of payload items, or a single + payload item such as a data form. + sessionid -- The current session's ID value. + flow -- If True, process the Iq result using the + command workflow methods contained in the + session instead of returning the response + stanza itself. Defaults to False. + timeout -- The length of time (in seconds) to wait for a + response before exiting the send call + if blocking is used. Defaults to + slixmpp.xmlstream.RESPONSE_TIMEOUT + callback -- Optional reference to a stream handler + function. Will be executed when a reply + stanza is received if flow=False. + """ + iq = self.xmpp.Iq() + iq['type'] = 'set' + iq['to'] = jid + iq['from'] = ifrom + iq['command']['node'] = node + iq['command']['action'] = action + if sessionid is not None: + iq['command']['sessionid'] = sessionid + if payload is not None: + if not isinstance(payload, list): + payload = [payload] + for item in payload: + iq['command'].append(item) + if not flow: + return iq.send(**kwargs) + else: + iq.send(callback=self._handle_command_result) + + def start_command(self, jid, node, session, ifrom=None): + """ + Initiate executing a command provided by a remote agent. + + The provided session dictionary should contain: + next -- A handler for processing the command result. + error -- A handler for processing any error stanzas + generated by the request. + + Arguments: + jid -- The JID to send the command request. + node -- The node for the desired command. + session -- A dictionary of relevant session data. + ifrom -- Optionally specify the sender's JID. + """ + session['jid'] = jid + session['node'] = node + session['timestamp'] = time.time() + if 'payload' not in session: + session['payload'] = None + + iq = self.xmpp.Iq() + iq['type'] = 'set' + iq['to'] = jid + iq['from'] = ifrom + session['from'] = ifrom + iq['command']['node'] = node + iq['command']['action'] = 'execute' + if session['payload'] is not None: + payload = session['payload'] + if not isinstance(payload, list): + payload = list(payload) + for stanza in payload: + iq['command'].append(stanza) + sessionid = 'client:pending_' + iq['id'] + session['id'] = sessionid + self.sessions[sessionid] = session + iq.send(callback=self._handle_command_result) + + def continue_command(self, session, direction='next'): + """ + Execute the next action of the command. + + Arguments: + session -- All stored data relevant to the current + command session. + """ + sessionid = 'client:' + session['id'] + self.sessions[sessionid] = session + + self.send_command(session['jid'], + session['node'], + ifrom=session.get('from', None), + action=direction, + payload=session.get('payload', None), + sessionid=session['id'], + flow=True) + + def cancel_command(self, session): + """ + Cancel the execution of a command. + + Arguments: + session -- All stored data relevant to the current + command session. + """ + sessionid = 'client:' + session['id'] + self.sessions[sessionid] = session + + self.send_command(session['jid'], + session['node'], + ifrom=session.get('from', None), + action='cancel', + payload=session.get('payload', None), + sessionid=session['id'], + flow=True) + + def complete_command(self, session): + """ + Finish the execution of a command workflow. + + Arguments: + session -- All stored data relevant to the current + command session. + """ + sessionid = 'client:' + session['id'] + self.sessions[sessionid] = session + + self.send_command(session['jid'], + session['node'], + ifrom=session.get('from', None), + action='complete', + payload=session.get('payload', None), + sessionid=session['id'], + flow=True) + + def terminate_command(self, session): + """ + Delete a command's session after a command has completed + or an error has occured. + + Arguments: + session -- All stored data relevant to the current + command session. + """ + sessionid = 'client:' + session['id'] + try: + del self.sessions[sessionid] + except Exception as e: + log.error("Error deleting adhoc command session: %s" % e.message) + + def _handle_command_result(self, iq): + """ + Process the results of a command request. + + Will execute the 'next' handler stored in the session + data, or the 'error' handler depending on the Iq's type. + + Arguments: + iq -- The command response. + """ + sessionid = 'client:' + iq['command']['sessionid'] + pending = False + + if sessionid not in self.sessions: + pending = True + pendingid = 'client:pending_' + iq['id'] + if pendingid not in self.sessions: + return + sessionid = pendingid + + session = self.sessions[sessionid] + sessionid = 'client:' + iq['command']['sessionid'] + session['id'] = iq['command']['sessionid'] + + self.sessions[sessionid] = session + + if pending: + del self.sessions[pendingid] + + handler_type = 'next' + if iq['type'] == 'error': + handler_type = 'error' + handler = session.get(handler_type, None) + if handler: + handler(iq, session) + elif iq['type'] == 'error': + self.terminate_command(session) + + if iq['command']['status'] == 'completed': + self.terminate_command(session) |