1 files changed, 84 insertions, 0 deletions
diff --git a/sleekxmpp/xmlstream/handler/callback.py b/sleekxmpp/xmlstream/handler/callback.py
new file mode 100644
index 0000000..f0a7285
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+++ b/sleekxmpp/xmlstream/handler/callback.py
@@ -0,0 +1,84 @@
+"""
+    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.xmlstream.handler.base import BaseHandler
+
+
+class Callback(BaseHandler):
+
+    """
+    The Callback handler will execute a callback function with
+    matched stanzas.
+
+    The handler may execute the callback either during stream
+    processing or during the main event loop.
+
+    Callback functions are all executed in the same thread, so be
+    aware if you are executing functions that will block for extended
+    periods of time. Typically, you should signal your own events using the
+    SleekXMPP object's event() method to pass the stanza off to a threaded
+    event handler for further processing.
+
+    Methods:
+        prerun -- Overrides BaseHandler.prerun
+        run    -- Overrides BaseHandler.run
+    """
+
+    def __init__(self, name, matcher, pointer, thread=False,
+                 once=False, instream=False, stream=None):
+        """
+        Create a new callback handler.
+
+        Arguments:
+            name     -- The name of the handler.
+            matcher  -- A matcher object for matching stanza objects.
+            pointer  -- The function to execute during callback.
+            thread   -- DEPRECATED. Remains only for backwards compatibility.
+            once     -- Indicates if the handler should be used only
+                        once. Defaults to False.
+            instream -- Indicates if the callback should be executed
+                        during stream processing instead of in the
+                        main event loop.
+            stream   -- The XMLStream instance this handler should monitor.
+        """
+        BaseHandler.__init__(self, name, matcher, stream)
+        self._pointer = pointer
+        self._once = once
+        self._instream = instream
+
+    def prerun(self, payload):
+        """
+        Execute the callback during stream processing, if
+        the callback was created with instream=True.
+
+        Overrides BaseHandler.prerun
+
+        Arguments:
+            payload -- The matched stanza object.
+        """
+        BaseHandler.prerun(self, payload)
+        if self._instream:
+            self.run(payload, True)
+
+    def run(self, payload, instream=False):
+        """
+        Execute the callback function with the matched stanza payload.
+
+        Overrides BaseHandler.run
+
+        Arguments:
+            payload  -- The matched stanza object.
+            instream -- Force the handler to execute during
+                        stream processing. Used only by prerun.
+                        Defaults to False.
+        """
+        if not self._instream or instream:
+            BaseHandler.run(self, payload)
+            self._pointer(payload)
+            if self._once:
+                self._destroy = True