Re: [matplotlib-devel] IPython Comm backend

[Jason G. <jas...@cr...>]

On 10/16/13 3:46 PM, Jason Grout wrote:
> On 10/16/13 1:58 PM, Michael Droettboom wrote:
>> Sorry to take so long to get to this. This is a nice piece of work.
>>
>> The most obvious thing is that this is a copy-and-paste of the existing
>> WebAgg backend -- and maintaining the two is going to be much harder
>> than building both out of the same pieces.  As of 6389d14f, the WebAgg
>> backend was refactored so that the transport that it uses to communicate
>> to the browser is no longer hard coded.  This was done in large part to
>> support working with IPyhton in this way.  (That is, it used to only
>> communicate with the browser through Tornado, but now it can be anything
>> that can send bits back and forth).  There's an example of this in
>> `examples/user_interfaces/embedding_webagg.py` that shows how to do this
>> (using Tornado, but again, it doesn't have to be). There's no guarantees
>> that this interface is sufficient, so it may require some back and forth
>> on this to make it all work.
>>
>> I think the first thing I would do would be to refactor this to use
>> that.  It's a little hard to tell what you've changed from the original
>> WebAgg backend to get it to support IPython.  If it were built on top
>> of, rather than in addition to, WebAgg, that would be more obvious.
>
> Thanks for the feedback.  I was thinking that a refactor to pull out the
> communication layer would be really nice.
>
> I didn't change the WebAgg backend because I figured you wanted it
> around still.  I figured a plain old diff with the file would reveal
> changes.
>
> Anyways, thanks for the pointer to the refactor commit.  I hope to look
> at this again sometime soon.
>

Following a very helpful conversation with Michael this morning in the 
dev hangout, I got this working with the current master (of matplotlib 
and ipython).  The refactoring made the code much better; thanks!

I updated the pull request at 
https://github.com/matplotlib/matplotlib/pull/2524

To test this, run IPython (master branch, to get the comm commits), and 
put this in a cell: 
https://github.com/matplotlib/matplotlib/pull/2524#issuecomment-28539813

Then you can execute something like:

from matplotlib.figure import Figure
import numpy as np
fig = Figure()
a = fig.add_subplot(111)
t = np.arange(0.0, 3.0, 0.01)
s = np.sin(2 * np.pi * t)
a.plot(t, s)
CommFigure(fig)

and get a live figure in the IPython notebook that uses the comm 
messaging infrastructure.

Michael---do you have time to take it from here?

Thanks,

Jason