--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plugins/plugin_xep_0020.py	Thu Sep 29 12:05:25 2011 +0200
@@ -0,0 +1,115 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+"""
+SAT plugin for managing xep-0020
+Copyright (C) 2009, 2010, 2011  Jérôme Poisson (goffi@goffi.org)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+"""
+
+from logging import debug, info, warning, error
+from twisted.words.protocols.jabber import client, jid
+from twisted.words.xish import domish
+
+from zope.interface import implements
+
+try:
+    from twisted.words.protocols.xmlstream import XMPPHandler
+except ImportError:
+    from wokkel.subprotocols import XMPPHandler
+
+from wokkel import disco, iwokkel, data_form
+
+NS_FEATURE_NEG = 'http://jabber.org/protocol/feature-neg'
+
+PLUGIN_INFO = {
+"name": "XEP 0020 Plugin",
+"import_name": "XEP-0020",
+"type": "XEP",
+"protocols": ["XEP-0020"],
+"main": "XEP_0020",
+"handler": "yes",
+"description": _("""Implementation of Feature Negotiation""")
+}
+
+class XEP_0020():
+
+    def __init__(self, host):
+        info(_("Plugin XEP_0020 initialization"))
+    
+    def getHandler(self, profile):
+        return XEP_0020_handler()
+
+    def getFeatureElt(self, elt):
+        """Check element's children to find feature elements
+        @param elt: domish.Element
+        @return: feature elements"""
+        return filter(lambda elt: elt.name == 'feature', elt.elements())
+
+    def getChoosedOptions(self, elt):
+        """Return choosed feature for feature element
+        @param elt: feature domish element
+        @return: dict with feature name as key, and choosed option as value"""
+        form = data_form.Form.fromElement(elt.firstChildElement())
+        result = {}
+        for field in form.fields:
+            values = form.fields[field].values
+            result[field] = values[0] if values else None
+            if len(values)>1:
+                warning(_("More than one value choosed for %s, keeping the first one") % field)
+        return result
+
+    def negociate(self, feature_elt, form_type, negociable_values):
+        """Negociate the feature options
+        @param feature_elt: feature domish element
+        @param form_type: the option to negociate
+        @param negociable_values: acceptable values for this negociation"""
+        form = data_form.Form.fromElement(feature_elt.firstChildElement())
+        options = [option.value for option in form.fields[form_type].options]
+        for value in negociable_values:
+            if value in options:
+                return value
+        return None
+
+    def chooseOption(self, options_dict):
+        """Build a feature element with choosed options
+        @param options_dict: dict with feature as key and choosed option as value"""
+        feature_elt = domish.Element((NS_FEATURE_NEG, 'feature'))
+        x_form = data_form.Form('submit')
+        x_form.makeFields(options_dict)
+        feature_elt.addChild(x_form.toElement())
+        return feature_elt
+
+    def proposeFeatures(self, options_dict, namespace = None):
+        """Build a feature element with options to propose
+        @param options_dict: dict with feature as key and list of acceptable options as value
+        @param namespace: feature namespace"""
+        feature_elt = domish.Element((NS_FEATURE_NEG, 'feature'))
+        x_form = data_form.Form('form', formNamespace=namespace)
+        for field in options_dict:
+            x_form.addField(data_form.Field('list-single', field,
+                            options=[data_form.Option(_option) for _option in options_dict[field]]))
+        feature_elt.addChild(x_form.toElement())
+        return feature_elt
+
+class XEP_0020_handler(XMPPHandler):
+    implements(iwokkel.IDisco)
+    
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
+        return [disco.DiscoFeature(NS_FEATURE_NEG)]
+
+    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
+        return []
+