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[source]

PointField

class PointField[source]

LineStringField

class LineStringField[source]

PolygonField

class PolygonField[source]

MultiPointField

class MultiPointField[source]

MultiLineStringField

class MultiLineStringField[source]

MultiPolygonField

class MultiPolygonField[source]

GeometryCollectionField

class GeometryCollectionField[source]

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.base_layer

A string that specifies the identifier for the default base map layer to be used by the corresponding JavaScript map widget. It is passed as part of the widget options when rendering, allowing the MapWidget to determine which map tile provider or base layer to initialize (default is None).

BaseGeometryWidget.geom_type

The OpenGIS geometry type, generally set by the form field.

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[source]

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 base layer name, identified by the base_layer class attribute.

OpenLayersWidget

class OpenLayersWidget[source]

This is the default widget used by all GeoDjango form fields. Attributes are:

base_layer

nasaWorldview

template_name

gis/openlayers.html.

map_srid

3857

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[source]

This widget specialized OpenLayersWidget and uses an OpenStreetMap base layer to display geographic objects on. Attributes are:

base_layer

osm

default_lat
default_lon

The default center latitude and longitude are 47 and 5, 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.

The OSMWidget no longer uses a custom template. Consequently, the gis/openlayers-osm.html template was removed.

Customizing the base layer used in OpenLayers-based widgets

To customize the base layer displayed in OpenLayers-based geometry widgets, define a new layer builder in a custom JavaScript file. For example:

path-to-file.js
 MapWidget.layerBuilder.custom_layer_name = function () {
     // Return an OpenLayers layer instance.
     return new ol.layer.Tile({source: new ol.source.<ChosenSource>()});
 };

Then, subclass a standard geometry widget and set the base_layer:

from django.contrib.gis.forms.widgets import OpenLayersWidget


class YourCustomWidget(OpenLayersWidget):
    base_layer = "custom_layer_name"

    class Media:
        js = ["path-to-file.js"]
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