GeoDjango provides some specialized form fields and widgets in order to visually display and edit geolocalized data on a map. By default, they use OpenLayers-powered maps, with a base WMS layer provided by Metacarta.
In addition to the regular form field arguments, GeoDjango form fields take the following optional arguments.
GeoDjango form widgets allow you to display and edit geographic data on a
visual map.
Note that none of the currently available widgets supports 3D geometries, hence
geometry fields will fallback using a simple Textarea
widget for such data.
GeoDjango widgets are template-based, so their attributes are mostly different from other Django widget attributes.
BaseGeometryWidget.
geom_type
¶The OpenGIS geometry type, generally set by the form field.
BaseGeometryWidget.
map_height
¶BaseGeometryWidget.
map_width
¶Height and width of the widget map (default is 400x600).
BaseGeometryWidget.
map_srid
¶SRID code used by the map (default is 4326).
BaseGeometryWidget.
display_raw
¶Boolean value specifying if a textarea input showing the serialized
representation of the current geometry is visible, mainly for debugging
purposes (default is False
).
BaseGeometryWidget.
supports_3d
¶Indicates if the widget supports edition of 3D data (default is False
).
BaseGeometryWidget.
template_name
¶The template used to render the map widget.
You can pass widget attributes in the same manner that for any other Django widget. For example:
from django.contrib.gis import forms
class MyGeoForm(forms.Form):
point = forms.PointField(widget=
forms.OSMWidget(attrs={'map_width': 800, 'map_height': 500}))
BaseGeometryWidget
BaseGeometryWidget
¶This is an abstract base widget containing the logic needed by subclasses.
You cannot directly use this widget for a geometry field.
Note that the rendering of GeoDjango widgets is based on a template,
identified by the template_name
class attribute.
OpenLayersWidget
OpenLayersWidget
¶This is the default widget used by all GeoDjango form fields.
template_name
is gis/openlayers.html
.
OpenLayersWidget
and OSMWidget
use the openlayers.js
file
hosted on the openlayers.org
website. This works for basic usage
during development, but isn’t appropriate for a production deployment as
openlayers.org/api/
has no guaranteed uptime and runs on a slow server.
You are therefore advised to subclass these widgets in order to specify
your own version of the openlayers.js
file in the js
property of
the inner Media
class (see Assets as a static definition). You
can host a copy of openlayers.js
tailored to your needs on your own server or refer to a copy from a
content-delivery network like https://cdnjs.com/. This will also allow
you to serve the JavaScript file(s) using the https
protocol if needed.
OSMWidget
OSMWidget
¶This widget uses an OpenStreetMap base layer (Mapnik) to display geographic
objects on.
template_name
is gis/openlayers-osm.html
.
The OpenLayersWidget
note about JavaScript file hosting above also
applies here. See also this FAQ answer about https
access to map
tiles.
May 02, 2016