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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 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.

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

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 cdnjs.cloudflare.com content-delivery network. You can subclass these widgets in order to specify your own version of the OpenLayers.js file tailored to your needs in the js property of the inner Media class (see Assets as a static definition).

Changed in Django 1.11:

Older versions use OpenLayers.js from openlayers.org which isn’t suitable for production use since it offers no guaranteed uptime and runs on a slow server.

Also, the widget nows uses OpenLayers 3 instead of OpenLayers 2.

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 and 5, respectively, which is a location in eastern France.

The OpenLayersWidget note about JavaScript file hosting above also applies here. See also this FAQ answer about https access to map tiles.