From 748dcd733eb3080a5736ca65cfc1c1e195ff45c6 2014-08-11 18:36:59
From: Jason Grout <jgrout6@bloomberg.net>
Date: 2014-08-11 18:36:59
Subject: [PATCH] Make the widget comm attribute more straigtforward
Instead of automagically instantiating a comm when it is accessed, require a call to open(). This makes the comm attribute much less magical, and hopefully more understandable.
---
diff --git a/IPython/html/widgets/widget.py b/IPython/html/widgets/widget.py
index 2107f21..f9ee5fc 100644
--- a/IPython/html/widgets/widget.py
+++ b/IPython/html/widgets/widget.py
@@ -100,7 +100,7 @@ class Widget(LoggingConfigurable):
registered in the front-end to create and sync this widget with.""")
_view_name = Unicode(help="""Default view registered in the front-end
to use to represent the widget.""", sync=True)
- _comm = Instance('IPython.kernel.comm.Comm')
+ comm = Instance('IPython.kernel.comm.Comm')
msg_throttle = Int(3, sync=True, help="""Maximum number of msgs the
front-end can send before receiving an idle msg from the back-end.""")
@@ -133,20 +133,12 @@ class Widget(LoggingConfigurable):
# Properties
#-------------------------------------------------------------------------
- @property
- def comm(self):
- """Gets the Comm associated with this widget.
-
- If a Comm doesn't exist yet, a Comm will be created automagically."""
- self.open()
- return self._comm
-
def open(self):
"""Open a comm to the frontend if one isn't already open."""
- if self._comm is None:
+ if self.comm is None:
# Create a comm.
- self._comm = Comm(target_name=self._model_name)
- self._comm.on_msg(self._handle_msg)
+ self.comm = Comm(target_name=self._model_name)
+ self.comm.on_msg(self._handle_msg)
Widget.widgets[self.model_id] = self
# first update
@@ -169,10 +161,10 @@ class Widget(LoggingConfigurable):
Closes the underlying comm.
When the comm is closed, all of the widget views are automatically
removed from the front-end."""
- if self._comm is not None:
+ if self.comm is not None:
Widget.widgets.pop(self.model_id, None)
- self._comm.close()
- self._comm = None
+ self.comm.close()
+ self.comm = None
def send_state(self, key=None):
"""Sends the widget state, or a piece of it, to the front-end.
@@ -393,7 +385,10 @@ class DOMWidget(Widget):
selector: unicode (optional, kwarg only)
JQuery selector to use to apply the CSS key/value. If no selector
is provided, an empty selector is used. An empty selector makes the
- front-end try to apply the css to the top-level element.
+ front-end try to apply the css to a default element. The default
+ element is an attribute unique to each view, which is a DOM element
+ of the view that should be styled with common CSS (see
+ `$el_to_style` in the Javascript code).
"""
if value is None:
css_dict = dict_or_key