GeoDjango Forms API
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 NASA.
Field arguments
In addition to the regular form field arguments, GeoDjango form fields take the following optional arguments.
srid
Field.srid
This is the SRID code that the field value should be transformed to. For example, if the map widget SRID is different from the SRID more generally used by your application or database, the field will automatically convert input values into that SRID.
geom_type
Field.geom_type
You generally shouldn’t have to set or change that attribute which should be set up depending on the field class. It matches the OpenGIS standard geometry name.
Form field classes
GeometryField
class GeometryField
PointField
class PointField
LineStringField
class LineStringField
PolygonField
class PolygonField
MultiPointField
class MultiPointField
MultiLineStringField
class MultiLineStringField
MultiPolygonField
class MultiPolygonField
GeometryCollectionField
class GeometryCollectionField
Form widgets
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 Textarea
widget for such data.
Widget attributes
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).
Deprecated since version 4.2: map_height
and map_width
attributes are deprecated, use CSS to size map widgets instead.
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={"display_raw": True}))
Widget classes
BaseGeometryWidget
class 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
class OpenLayersWidget
This is the default widget used by all GeoDjango form fields. template_name
is gis/openlayers.html
.
OpenLayersWidget
and OSMWidget use the ol.js
file hosted on the cdn.jsdelivr.net
content-delivery network. You can subclass these widgets in order to specify your own version of the ol.js
file in the js
property of the inner Media
class (see Assets as a static definition).
OSMWidget
class OSMWidget
This widget uses an OpenStreetMap base layer to display geographic objects on. Attributes are:
template_name
gis/openlayers-osm.html
default_lat
default_lon
The default center latitude and longitude are
47
and5
, respectively, which is a location in eastern France.default_zoom
The default map zoom is
12
.
The OpenLayersWidget note about JavaScript file hosting above also applies here. See also this FAQ answer about https
access to map tiles.