console does not display text/plain alternative for display_data?

[jankatins]

The R kernel sends plots via display_data messages and includes a text/plain representation in the message bundle. Unfortunately, it seems that the console does not display the text/plain message:

[ipython-notebook] λ jupyter console --kernel=ir32
Jupyter Console 4.0.3

[ZMQTerminalIPythonApp] Loading IPython extension: storemagic

In [1]: plot(1:10)

In [2]:

The message bundle looks like this:

List of 3
 $ text/plain   : chr "plot without title"
 $ image/png    : raw [1:12628] 89 50 4e 47 ...
 $ image/svg+xml: chr "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlin"| __truncated__

This is IRkernel/IRkernel#262

[jankatins]

This also looks wrong:

[ZMQTerminalIPythonApp] Loading IPython extension: storemagic

[takluyver]

It looks like it works with the execute_result message (that generates an Out prompt), but not with display_data:

In [1]: class A():
      :     def _repr_png_(self):
      :         return b'oijoij'
      :     

In [2]: a= A()

In [3]: a
Out[3]: <__main__.A at 0x7f052871f1d0>

In [4]: from IPython.display import display

In [5]: display(a)

[flying-sheep]

well I was against changing it 😉

[flying-sheep]

well, the cause is easy to identify:

1. handle_rich_data is called, which in turn calls handle_image and then returns True. when returning True, text/plain isn’t used.
2. handle_image_PIL checks if the mimetype is PNG or SVG and returns if not, without doing anything.

we should make handle_image return True/False depending on if its delegated function can handle it the format.

AGAIN a bug exposed by having SVG! this is so useful!

[takluyver]

Thanks, well worked out. I've just opened #77 for it, and then noticed that you've done a fix as well. You've opened a PR against your own fork of the repo, though ;-)

[flying-sheep]

whoops

[jankatins]

AGAIN a bug exposed by having SVG! this is so useful!

More "(ab)using users as guinea pigs"... :-)