local anywidget failure when plotting polygons but works fine in binder

[emileten]

I am trying to use lonboard.SolidPolygonLayer to plot polygons from a list of GeoJSONs that I load using geopandas. The rendering fails with what seems to be an anywidget error (see screen below, plus console screen).

Crucially, the exact same task runs fine if I run it in the binder environment provided in this repository, so it has something to do with my set up. I tried to replicate the binder environment by pip-freezing it and wrapping it all up in a conda environment with the same python version as in binder, but the error remains.

Any thoughts ? Any help is welcome, thanks for reading this (And for the nice package 😄)

Here is the information necessary to reproduce the error.

• notebook to run.

• the json file with an example of the items of which I am trying to plot the boundaries (this json file is read in the notebook)

• To mimic my environment, run the notebook in a conda environment using this configuration file. This configuration is meant to mimic the binder environment provided in this repository : all packages, including jupyter related ones, are the same version.

[kylebarron]

SyntaxError: invalid regular expression flag usually means that the JS part of lonboard wasn't included in the install.

How did you install it?

run the notebook in a conda environment using this configuration file.

Ah looks like lonboard is incorrectly packaged for conda, cc @giswqs in #223

[emileten]

Another approach resulted in the same error

git clone git@github.com:developmentseed/lonboard.git
cd lonboard
python -m venv .venv
source .venv/bin/activate
pip install -e .
pip install ipykernel jupyter jupyterlab
python -m ipykernel install --user --name=lonboard-venv
jupyter lab

Then running the above notebook (also tried reloading the browser page)

[kylebarron]

you can't install from git without manually building the js parts, see DEVELOP.md. Otherwise you need to pip install from PyPI, which will download a pre-built JS bundle as part of the python package

[vincentsarago]

@kylebarron do you think we could update the develop.md to make it a bit more clear what are the steps for local install? 🙏

[vincentsarago]

Oo @emileten started a PR do add some info 🙌

[emileten]

you can't install from git without manually building the js parts, see DEVELOP.md

Yes thanks 👍.

update the develop.md to make it a bit more clear what are the steps for local install?

that would be great ! I started a PR, but maybe pointing to develop.md in the main docs and make the JS build dependency more explicit in develop.md would be useful!

[emileten]

The only time I've seen that error is where the JS part wasn't included.

Alright so, that's the answer to this problem, the JS code was not built (i.e I was missing the lonboard/static folder). I ran npm run build and my problem is fixed. The reason I didn't have the JS files in the first place is that I installed from source (pip install from cloned repository). I opened a PR to add in the docs an installation-from-source instruction #226.