Example, in response to this StackOverflow question, of using a Bootstrap modal popup to update multiple records selected in a Flask-Admin batch action.
git clone https://github.com/pjcunningham/flask-admin-modal.git
cd flask-admin-modal
# (optional, create a virtual environment)
virtualenv venv && source venv/bin/activate
# fetch dependencies; add '--user' if not using a virtualenv
pip install -r requirements.txt
# Set Flask environment variable e.g. Windows CMD
set FLASK_APP=run.py
# Create/Populate data
flask create-database
# launch app
flask run