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.
In addition to the regular form field arguments, GeoDjango form fields take the following optional arguments.
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
¶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.
GeometryField
¶PointField
¶LineStringField
¶PolygonField
¶MultiPointField
¶MultiLineStringField
¶MultiPolygonField
¶GeometryCollectionField
¶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.
GeoDjango widgets are template-based, so their attributes are mostly different from other Django widget attributes.
The OpenGIS geometry type, generally set by the form field.
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.
SRID code used by the map (default is 4326).
Boolean value specifying if a textarea input showing the serialized
representation of the current geometry is visible, mainly for debugging
purposes (default is False
).
Indicates if the widget supports edition of 3D data (default is False
).
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}))
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
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
This widget uses an OpenStreetMap base layer to display geographic objects on. Attributes are:
gis/openlayers-osm.html
The default center latitude and longitude are 47
and 5
,
respectively, which is a location in eastern France.
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.
Dec 25, 2023