Django documentation

  • 1.7
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  • Documentation version: 1.6

GeoDjango Forms API

New in Django 1.6.

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.

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 setup 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 simple 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).

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}))

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 openlayers.js file hosted on the openlayers.org Web site. This works for basic usage during development, but isn’t appropropriate 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 http://cdnjs.com/. This will also allow you to serve the JavaScript file(s) using the https protocol if needed.

OSMWidget

class 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.

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