Merge pull request #7554 from jdfreder/interact-fix

Use Output widget with Interact

IPython/html/widgets/interaction.py

@@ -14,7 +14,7 @@ from inspect import getcallargs
 from IPython.core.getipython import get_ipython
 from IPython.html.widgets import (Widget, Text,
     FloatSlider, IntSlider, Checkbox, Dropdown,
-    Box, Button, DOMWidget)
+    Box, Button, DOMWidget, Output)
 from IPython.display import display, clear_output
 from IPython.utils.py3compat import string_types, unicode_type
 from IPython.utils.traitlets import HasTraits, Any, Unicode
@@ -204,10 +204,15 @@ def interactive(__interact_f, **kwargs):
     if manual:
         manual_button = Button(description="Run %s" % f.__name__)
         c.append(manual_button)
+
+    # Use an output widget to capture the output of interact.
+    output = Output()
+    c.append(output)
     container.children = c
 
     # Build the callback
     def call_f(name=None, old=None, new=None):
+        with output:
             container.kwargs = {}
             for widget in kwargs_widgets:
                 value = widget.value

IPython/html/widgets/tests/test_interaction.py

@@ -80,6 +80,7 @@ def check_widgets(container, **to_check):
     # build a widget dictionary, so it matches
     widgets = {}
     for w in container.children:
+        if hasattr(w, 'description'):
             widgets[w.description] = w
     
     for key, d in to_check.items():
@@ -138,7 +139,7 @@ def test_single_value_float():
 def test_single_value_int():
     for a in (1, 5, -3):
         c = interactive(f, a=a)
-        nt.assert_equal(len(c.children), 1)
+        nt.assert_equal(len(c.children), 2)
         w = c.children[0]
         check_widget(w,
             cls=widgets.IntSlider,
@@ -157,7 +158,7 @@ def test_list_tuple_2_int():
         c = interactive(f, tup=(1,-1))
     for min, max in [ (0,1), (1,10), (1,2), (-5,5), (-20,-19) ]:
         c = interactive(f, tup=(min, max), lis=[min, max])
-        nt.assert_equal(len(c.children), 2)
+        nt.assert_equal(len(c.children), 3)
         d = dict(
             cls=widgets.IntSlider,
             min=min,
@@ -174,7 +175,7 @@ def test_list_tuple_3_int():
         c = interactive(f, tup=(1,2,-1))
     for min, max, step in [ (0,2,1), (1,10,2), (1,100,2), (-5,5,4), (-100,-20,4) ]:
         c = interactive(f, tup=(min, max, step), lis=[min, max, step])
-        nt.assert_equal(len(c.children), 2)
+        nt.assert_equal(len(c.children), 3)
         d = dict(
             cls=widgets.IntSlider,
             min=min,
@@ -191,7 +192,7 @@ def test_list_tuple_2_float():
         c = interactive(f, tup=(0.5,-0.5))
     for min, max in [ (0.5, 1.5), (1.1,10.2), (1,2.2), (-5.,5), (-20,-19.) ]:
         c = interactive(f, tup=(min, max), lis=[min, max])
-        nt.assert_equal(len(c.children), 2)
+        nt.assert_equal(len(c.children), 3)
         d = dict(
             cls=widgets.FloatSlider,
             min=min,
@@ -210,7 +211,7 @@ def test_list_tuple_3_float():
         c = interactive(f, tup=(1,2.,-1.))
     for min, max, step in [ (0.,2,1), (1,10.,2), (1,100,2.), (-5.,5.,4), (-100,-20.,4.) ]:
         c = interactive(f, tup=(min, max, step), lis=[min, max, step])
-        nt.assert_equal(len(c.children), 2)
+        nt.assert_equal(len(c.children), 3)
         d = dict(
             cls=widgets.FloatSlider,
             min=min,
@@ -224,7 +225,7 @@ def test_list_tuple_str():
     values = ['hello', 'there', 'guy']
     first = values[0]
     c = interactive(f, tup=tuple(values), lis=list(values))
-    nt.assert_equal(len(c.children), 2)
+    nt.assert_equal(len(c.children), 3)
     d = dict(
         cls=widgets.Dropdown,
         value=first,
@@ -471,7 +472,7 @@ def test_call_decorated_kwargs_on_trait_change():
 
 def test_fixed():
     c = interactive(f, a=widgets.fixed(5), b='text')
-    nt.assert_equal(len(c.children), 1)
+    nt.assert_equal(len(c.children), 2)
     w = c.children[0]
     check_widget(w,
         cls=widgets.Text,

IPython/html/widgets/widget_output.py

@@ -34,15 +34,24 @@ class Output(DOMWidget):
             print('prints to output widget')"""
     _view_name = Unicode('OutputView', sync=True)
 
+    def __init__(self, *args, **kwargs):
+        super(Output, self).__init__(*args, **kwargs)
+        from IPython import get_ipython
+        ip = get_ipython()
+        if ip is not None and hasattr(ip, 'kernel'):
+            self._kernel = ip.kernel
+        else:
+            self._kernel = None
+
     def clear_output(self, *pargs, **kwargs):
         with self:
             clear_output(*pargs, **kwargs)
 
     def __enter__(self):
         """Called upon entering output widget context manager."""
+        if self._kernel is not None:
             self._flush()
-        kernel = get_ipython().kernel
-        session = kernel.session
+            session = self._kernel.session
             send = session.send
             self._original_send = send
             self._session = session
@@ -60,7 +69,7 @@ class Output(DOMWidget):
                         header=header, metadata=metadata)
 
                 # If this is a message type that we want to forward, forward it.
-            if stream is kernel.iopub_socket and msg_type in ['clear_output', 'stream', 'display_data']:
+                if stream is self._kernel.iopub_socket and msg_type in ['clear_output', 'stream', 'display_data']:
                     self.send(msg)
                 else: 
                     send(stream, msg, ident=ident, buffers=buffers, track=track)
@@ -69,6 +78,7 @@ class Output(DOMWidget):
 
     def __exit__(self, exception_type, exception_value, traceback):
         """Called upon exiting output widget context manager."""
+        if self._kernel is not None:
             self._flush()
             self._session.send = self._original_send