GeoAlchemy backend

If you want to store spatial information in a GIS database, Flask-Admin has you covered. The GeoAlchemy backend extends the SQLAlchemy backend (just as GeoAlchemy extends SQLAlchemy) to give you a pretty and functional map-based editor for your admin pages.

Notable features:

• Uses the amazing Leaflet Javascript library for displaying maps, with map data from Mapbox
• Uses Leaflet.Draw for editing geographic information interactively, including points, lines, and polygons
• Graceful fallback to editing GeoJSON data in a <textarea>, if the user has turned off Javascript
• Works with a Geometry SQL field that is integrated with Shapely objects

Getting Started

GeoAlchemy is based on SQLAlchemy, so you’ll need to complete the “getting started” directions for SQLAlchemy backend first. For GeoAlchemy, you’ll also need a map ID from Mapbox, a map tile provider. (Don’t worry, their basic plan is free, and works quite well.) Then, just include the map ID in your application settings:

app = Flask(__name__)
app.config['MAPBOX_MAP_ID'] = "example.abc123"

Note

Leaflet supports loading map tiles from any arbitrary map tile provider, but at the moment, Flask-Admin only supports Mapbox. If you want to use other providers, make a pull request!

Creating simple model

GeoAlchemy comes with a Geometry field that is carefully divorced from the Shapely library. Flask-Admin will use this field so that there are no changes necessary to other code. ModelView should be imported from geoa rather than the one imported from sqla:

from geoalchemy2 import Geometry
from flask.ext.admin.contrib.geoa import ModelView

# .. flask initialization
db = SQLAlchemy(app)

class Location(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True)
    point = db.Column(Geometry("POINT"))

if __name__ == '__main__':
    admin = Admin(app)
    admin.add_view(ModelView(User, db.session))

    db.create_all()
    app.run('0.0.0.0', 8000)

Limitations

There’s currently no way to sort, filter, or search on geometric fields in the admin. It’s not clear that there’s a good way to do so. If you have any ideas or suggestions, make a pull request!