Using ipyleaflet on Google Colab

[giswqs]

Exciting news! Goolge Colab now supports custom widgets like ipyleaflet (googlecolab/colabtools#498 (comment))

One caveat is that we have to add the following code block when displaying a map. I am trying to embed this code block into the Map class so that users don't have to add this long string of code manually.

from IPython.display import Javascript
display(Javascript('''
  google.colab.widgets.installCustomManager('https://ssl.gstatic.com/colaboratory-static/widgets/colab-cdn-widget-manager/6a14374f468a145a/manager.min.js');
'''))

Based on the ipython repr_mimebundle() function, I tried to add some code to this function, but it has no effect. Any advice? @martinRenou @davidbrochart @SylvainCorlay @jasongrout @maartenbreddels @blois

Relevant issues:

• Use _repr_mimebundle_ and require IPython 6.1 or later. ipywidgets#2021
• output widget append_display_data does not display widgets ipywidgets#1811

A Colab example: https://colab.research.google.com/drive/1DIjJP4HrbsmGsDluKYKSQceFWnhj2wPz

import ipyleaflet

class Map(ipyleaflet.Map):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

    def _repr_mimebundle_(self, **kwargs):

        # the code below has no effect.
        layer_control = ipyleaflet.LayersControl(position="topright")
        self.add_control(layer_control)

        # display(Javascript('''
        # google.colab.widgets.installCustomManager('https://ssl.gstatic.com/colaboratory-static/widgets/colab-cdn-widget-manager/6a14374f468a145a/manager.min.js');
        # '''))

m = Map()
m

[martinRenou]

I guess you could add this code snippet in Leaflet's __init__.py instead of under the _repr_mimebundle_?

Something like:

from IPython.display import Javascript

if colab:
    display(Javascript('''
      google.colab.widgets.installCustomManager('https://ssl.gstatic.com/colaboratory- 
   static/widgets/colab-cdn-widget-manager/6a14374f468a145a/manager.min.js');
    '''))

Overwriting the _repr_mimebundle_ function might break the widget's display logic.

[blois]

Colab will be iterating on the snippet required and will make it a bit easier to use (including making it one-time opt-in for the notebook).

This was published in googlecolab/colabtools#498 (comment) to allow collecting feedback on how well the API worked for various widget packages before we attempt to call it stable.