From d674ae2e050b4a08da4158a1a512fe0abd305a78 2014-08-04 21:22:16
From: Jonathan Frederic <jon.freder@gmail.com>
Date: 2014-08-04 21:22:16
Subject: [PATCH] Added on_events convinience method

---

diff --git a/IPython/utils/eventful.py b/IPython/utils/eventful.py
index 332915a..a986560 100644
--- a/IPython/utils/eventful.py
+++ b/IPython/utils/eventful.py
@@ -15,8 +15,8 @@ class EventfulDict(dict):
     set `EventfulDict`s that wrap those `dict`s.  Then you can wire the events
     to the same handlers if necessary.
 
-    See the on_add, on_set, and on_del methods for registering an event
-    handler."""
+    See the on_events, on_add, on_set, and on_del methods for registering 
+    event handlers."""
 
     def __init__(self, *args, **kwargs):
         """Public constructor"""
@@ -25,6 +25,20 @@ class EventfulDict(dict):
         self._set_callback = _void
         dict.__init__(self, *args, **kwargs)
 
+    def on_events(self, *callbacks):
+        """Register callbacks for add, set, and del actions.
+
+        See the doctstrings for on_(add/set/del) for details about each 
+        callback.
+
+        add_callback: callback or None
+        set_callback: callback or None
+        del_callback: callback or None"""
+        registers = ['on_add', 'on_set', 'on_del']
+        if len(callbacks) < len(registers):
+            raise ValueError('on_events takes {} callbacks'.format(len(registers)))
+        [getattr(self, n)(callbacks[i]) for i, n in enumerate(registers)]
+
     def on_add(self, callback):
         """Register a callback for when an item is added to the dict.
 
@@ -141,6 +155,22 @@ class EventfulList(list):
         self._reverse_callback = _void
         list.__init__(self, *pargs, **kwargs)
 
+    def on_events(self, *callbacks):
+        """Register callbacks for add, set, and del actions.
+
+        See the doctstrings for on_(insert/set/del/reverse/sort) for details 
+        about each callback.
+
+        insert_callback: callback or None
+        set_callback: callback or None
+        del_callback: callback or None
+        reverse_callback: callback or None
+        sort_callback: callback or None"""
+        registers = ['on_insert', 'on_set', 'on_del', 'on_reverse', 'on_sort']
+        if len(callbacks) < len(registers):
+            raise ValueError('on_events takes {} callbacks'.format(len(registers)))
+        [getattr(self, n)(callbacks[i]) for i, n in enumerate(registers)]
+
     def on_insert(self, callback):
         """Register a callback for when an item is inserted into the list.
 
diff --git a/IPython/utils/tests/test_traitlets.py b/IPython/utils/tests/test_traitlets.py
index 760e22e..4acd3ec 100644
--- a/IPython/utils/tests/test_traitlets.py
+++ b/IPython/utils/tests/test_traitlets.py
@@ -1181,22 +1181,11 @@ class TestEventful(TestCase):
         class A(HasTraits):
             x = EventfulList([c for c in 'abc'])
         a = A()
-
-        def handle_insert(index, value):
-            event_cache.append('insert')
-        def handle_del(index):
-            event_cache.append('del')
-        def handle_set(index, value):
-            event_cache.append('set')
-        def handle_reverse():
-            event_cache.append('reverse')
-        def handle_sort(*pargs, **kwargs):
-            event_cache.append('sort')
-        a.x.on_insert(handle_insert)
-        a.x.on_del(handle_del)
-        a.x.on_set(handle_set)
-        a.x.on_reverse(handle_reverse)
-        a.x.on_sort(handle_sort)
+        a.x.on_events(lambda i, x: event_cache.append('insert'), \
+            lambda i, x: event_cache.append('set'), \
+            lambda i: event_cache.append('del'), \
+            lambda: event_cache.append('reverse'), \
+            lambda *p, **k: event_cache.append('sort'))
 
         a.x.remove('c')
         # ab
@@ -1226,16 +1215,9 @@ class TestEventful(TestCase):
         class A(HasTraits):
             x = EventfulDict({c: c for c in 'abc'})
         a = A()
-
-        def handle_add(key, value):
-            event_cache.append('add')
-        def handle_del(key):
-            event_cache.append('del')
-        def handle_set(key, value):
-            event_cache.append('set')
-        a.x.on_add(handle_add)
-        a.x.on_del(handle_del)
-        a.x.on_set(handle_set)
+        a.x.on_events(lambda k, v: event_cache.append('add'), \
+            lambda k, v: event_cache.append('set'), \
+            lambda k: event_cache.append('del'))
 
         del a.x['c']
         # ab