To develop a new widget, add a py module to ipywe/ and a js module to js/src/, and add a line to js/src/loadwidgets.js.
Run
$ python setup.py build
to check for errors (especially in js code).
For a development installation (requires npm),
$ git clone https://github.com/scikit-beam/ipywe.git
$ cd ipywe
$ pip install -e .
$ jupyter nbextension install --py --symlink --sys-prefix ipywe
$ jupyter nbextension enable --py --sys-prefix ipywe
After making a change to a widget's Javascript code (must be in the ipywe directory),
$ chmod -x dev_js_update.sh
$ ./dev_js_update.sh
Note that the Jupyter server must be restarted after running these commands.