First pass at re-worked stream features.

Stream features now use stanza objects!

Features are given a ranking that expresses the dependency
relationships (since only one feature is negotiated at a time, the
dependency graph can be replaced by a line).

>>> xmpp.register_feature('my_feature', _my_handler,
>>>                       restart=True,   # Requires stream restart
>>>                       order=600)      # Ranking (out of ~ 10,000,
>>>                                       # lower #'s executed first)

SASL mechanisms may now be added or disabled as needed. Each mechanism
is given a priority value indicating the order in which the client
wishes for mechanisms to be tried. Higher priority numbers are executed
first.

>>> xmpp.register_sasl_mechanism('SASL-MECH', _mech_handler,
>>>                              priority=0)

Disabling a SASL mechanism:

>>> xmpp.remove_sasl_mechanism('ANONYMOUS')

1 files changed, 104 insertions, 0 deletions

diff --git a/sleekxmpp/stanza/sasl.py b/sleekxmpp/stanza/sasl.py
new file mode 100644
index 00000000..e55a72ad
--- /dev/null
+++ b/sleekxmpp/stanza/sasl.py
@@ -0,0 +1,104 @@
+"""
+    SleekXMPP: The Sleek XMPP Library
+    Copyright (C) 2010  Nathanael C. Fritz
+    This file is part of SleekXMPP.
+
+    See the file LICENSE for copying permission.
+"""
+
+from sleekxmpp.stanza import StreamFeatures
+from sleekxmpp.xmlstream import ElementBase, StanzaBase, ET
+from sleekxmpp.xmlstream import register_stanza_plugin
+
+
+class Mechanisms(ElementBase):
+
+    """
+    """
+
+    name = 'mechanisms'
+    namespace = 'urn:ietf:params:xml:ns:xmpp-sasl'
+    interfaces = set(('mechanisms', 'required'))
+    plugin_attrib = name
+    is_extension = True
+
+    def get_required(self):
+        """
+        """
+        return True
+
+    def get_mechanisms(self):
+        """
+        """
+        results = []
+        mechs = self.findall('{%s}mechanism' % self.namespace)
+        if mechs:
+            for mech in mechs:
+                results.append(mech.text)
+        return results
+
+    def set_mechanisms(self, values):
+        """
+        """
+        self.del_mechanisms()
+        for val in values:
+           mech = ET.Element('{%s}mechanism' % self.namespace)
+           mech.text = val
+           self.append(mech)
+
+    def del_mechanisms(self):
+        """
+        """
+        mechs = self.findall('{%s}mechanism' % self.namespace)
+        if mechs:
+            for mech in mechs:
+                self.xml.remove(mech)
+
+
+class Success(StanzaBase):
+
+    """
+    """
+
+    name = 'success'
+    namespace = 'urn:ietf:params:xml:ns:xmpp-sasl'
+    interfaces = set()
+    plugin_attrib = name
+
+
+class Failure(StanzaBase):
+
+    """
+    """
+
+    name = 'failure'
+    namespace = 'urn:ietf:params:xml:ns:xmpp-sasl'
+    interfaces = set()
+    plugin_attrib = name
+
+
+class Auth(StanzaBase):
+
+    """
+    """
+
+    name = 'auth'
+    namespace = 'urn:ietf:params:xml:ns:xmpp-sasl'
+    interfaces = set(('mechanism', 'value'))
+    plugin_attrib = name
+
+    def setup(self, xml):
+        StanzaBase.setup(self, xml)
+        self.xml.tag = self.tag_name()
+
+    def set_value(self, value):
+        self.xml.text = value
+
+    def get_value(self):
+        return self.xml.text
+
+    def del_value(self):
+        self.xml.text = ''
+
+
+register_stanza_plugin(StreamFeatures, Mechanisms)