""" Slixmpp: The Slick XMPP Library Copyright (C) 2010 Nathanael C. Fritz, Lance J.T. Stout This file is part of Slixmpp. See the file LICENSE for copying permission. """ from slixmpp.xmlstream import ElementBase, ET class DiscoInfo(ElementBase): """ XMPP allows for users and agents to find the identities and features supported by other entities in the XMPP network through service discovery, or "disco". In particular, the "disco#info" query type for stanzas is used to request the list of identities and features offered by a JID. An identity is a combination of a category and type, such as the 'client' category with a type of 'pc' to indicate the agent is a human operated client with a GUI, or a category of 'gateway' with a type of 'aim' to identify the agent as a gateway for the legacy AIM protocol. See for a full list of accepted category and type combinations. Features are simply a set of the namespaces that identify the supported features. For example, a client that supports service discovery will include the feature 'http://jabber.org/protocol/disco#info'. Since clients and components may operate in several roles at once, identity and feature information may be grouped into "nodes". If one were to write all of the identities and features used by a client, then node names would be like section headings. Example disco#info stanzas: Stanza Interface: node -- The name of the node to either query or return info from. identities -- A set of 4-tuples, where each tuple contains the category, type, xml:lang, and name of an identity. features -- A set of namespaces for features. Methods: add_identity -- Add a new, single identity. del_identity -- Remove a single identity. get_identities -- Return all identities in tuple form. set_identities -- Use multiple identities, each given in tuple form. del_identities -- Remove all identities. add_feature -- Add a single feature. del_feature -- Remove a single feature. get_features -- Return a list of all features. set_features -- Use a given list of features. del_features -- Remove all features. """ name = 'query' namespace = 'http://jabber.org/protocol/disco#info' plugin_attrib = 'disco_info' interfaces = set(('node', 'features', 'identities')) lang_interfaces = set(('identities',)) # Cache identities and features _identities = set() _features = set() def setup(self, xml=None): """ Populate the stanza object using an optional XML object. Overrides ElementBase.setup Caches identity and feature information. Arguments: xml -- Use an existing XML object for the stanza's values. """ ElementBase.setup(self, xml) self._identities = set([id[0:3] for id in self['identities']]) self._features = self['features'] def add_identity(self, category, itype, name=None, lang=None): """ Add a new identity element. Each identity must be unique in terms of all four identity components. Multiple, identical category/type pairs are allowed only if the xml:lang values are different. Likewise, multiple category/type/xml:lang pairs are allowed so long as the names are different. In any case, a category and type are required. Arguments: category -- The general category to which the agent belongs. itype -- A more specific designation with the category. name -- Optional human readable name for this identity. lang -- Optional standard xml:lang value. """ identity = (category, itype, lang) if identity not in self._identities: self._identities.add(identity) id_xml = ET.Element('{%s}identity' % self.namespace) id_xml.attrib['category'] = category id_xml.attrib['type'] = itype if lang: id_xml.attrib['{%s}lang' % self.xml_ns] = lang if name: id_xml.attrib['name'] = name self.xml.insert(0, id_xml) return True return False def del_identity(self, category, itype, name=None, lang=None): """ Remove a given identity. Arguments: category -- The general category to which the agent belonged. itype -- A more specific designation with the category. name -- Optional human readable name for this identity. lang -- Optional, standard xml:lang value. """ identity = (category, itype, lang) if identity in self._identities: self._identities.remove(identity) for id_xml in self.xml.findall('{%s}identity' % self.namespace): id = (id_xml.attrib['category'], id_xml.attrib['type'], id_xml.attrib.get('{%s}lang' % self.xml_ns, None)) if id == identity: self.xml.remove(id_xml) return True return False def get_identities(self, lang=None, dedupe=True): """ Return a set of all identities in tuple form as so: (category, type, lang, name) If a language was specified, only return identities using that language. Arguments: lang -- Optional, standard xml:lang value. dedupe -- If True, de-duplicate identities, otherwise return a list of all identities. """ if dedupe: identities = set() else: identities = [] for id_xml in self.xml.findall('{%s}identity' % self.namespace): xml_lang = id_xml.attrib.get('{%s}lang' % self.xml_ns, None) if lang is None or xml_lang == lang: id = (id_xml.attrib['category'], id_xml.attrib['type'], id_xml.attrib.get('{%s}lang' % self.xml_ns, None), id_xml.attrib.get('name', None)) if dedupe: identities.add(id) else: identities.append(id) return identities def set_identities(self, identities, lang=None): """ Add or replace all identities. The identities must be a in set where each identity is a tuple of the form: (category, type, lang, name) If a language is specifified, any identities using that language will be removed to be replaced with the given identities. NOTE: An identity's language will not be changed regardless of the value of lang. Arguments: identities -- A set of identities in tuple form. lang -- Optional, standard xml:lang value. """ self.del_identities(lang) for identity in identities: category, itype, lang, name = identity self.add_identity(category, itype, name, lang) def del_identities(self, lang=None): """ Remove all identities. If a language was specified, only remove identities using that language. Arguments: lang -- Optional, standard xml:lang value. """ for id_xml in self.xml.findall('{%s}identity' % self.namespace): if lang is None: self.xml.remove(id_xml) elif id_xml.attrib.get('{%s}lang' % self.xml_ns, None) == lang: self._identities.remove(( id_xml.attrib['category'], id_xml.attrib['type'], id_xml.attrib.get('{%s}lang' % self.xml_ns, None))) self.xml.remove(id_xml) def add_feature(self, feature): """ Add a single, new feature. Arguments: feature -- The namespace of the supported feature. """ if feature not in self._features: self._features.add(feature) feature_xml = ET.Element('{%s}feature' % self.namespace) feature_xml.attrib['var'] = feature self.xml.append(feature_xml) return True return False def del_feature(self, feature): """ Remove a single feature. Arguments: feature -- The namespace of the removed feature. """ if feature in self._features: self._features.remove(feature) for feature_xml in self.xml.findall('{%s}feature' % self.namespace): if feature_xml.attrib['var'] == feature: self.xml.remove(feature_xml) return True return False def get_features(self, dedupe=True): """Return the set of all supported features.""" if dedupe: features = set() else: features = [] for feature_xml in self.xml.findall('{%s}feature' % self.namespace): if dedupe: features.add(feature_xml.attrib['var']) else: features.append(feature_xml.attrib['var']) return features def set_features(self, features): """ Add or replace the set of supported features. Arguments: features -- The new set of supported features. """ self.del_features() for feature in features: self.add_feature(feature) def del_features(self): """Remove all features.""" self._features = set() for feature_xml in self.xml.findall('{%s}feature' % self.namespace): self.xml.remove(feature_xml)