GeoDjango Forms APILink to this heading
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 argumentsLink to this heading
In addition to the regular form field arguments, GeoDjango form fields take the following optional arguments.
sridLink to this heading
- Field.sridLink to this definition
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_typeLink to this heading
- Field.geom_typeLink to this definition
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.
max_geom_collectionsLink to this heading
- Field.max_geom_collectionsLink to this definition
-
The maximum number of geometry collections the field accepts before refusing to parse the input and raising a
ValidationError. This guards against crashes in the underlying GEOS library when parsing deeply nestedGEOMETRYCOLLECTIONinput. It defaults to198.The limit is applied differently depending on the input format: for well-known text (WKT) it bounds the nesting depth, while for well-known binary (WKB and hex-encoded WKB) it bounds the total number of geometry collections (both breadth and depth). As a result, the same value may accept a wide, shallow collection as WKT but reject it as WKB. For GeoJSON, the limit is not applied at all, since GDAL parses that input type instead.
Increase this value (or set to
None) only if you must accept legitimately deep geometries, since doing so reduces protection against fatal errors.
Form field classesLink to this heading
GeometryFieldLink to this heading
- class GeometryFieldLink to this definition
PointFieldLink to this heading
- class PointFieldLink to this definition
LineStringFieldLink to this heading
- class LineStringFieldLink to this definition
PolygonFieldLink to this heading
- class PolygonFieldLink to this definition
MultiPointFieldLink to this heading
- class MultiPointFieldLink to this definition
MultiLineStringFieldLink to this heading
- class MultiLineStringFieldLink to this definition
MultiPolygonFieldLink to this heading
- class MultiPolygonFieldLink to this definition
GeometryCollectionFieldLink to this heading
- class GeometryCollectionFieldLink to this definition
Form widgetsLink to this heading
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 attributesLink to this heading
GeoDjango widgets are template-based, so their attributes are mostly different from other Django widget attributes.
- BaseGeometryWidget.base_layerLink to this definition
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
MapWidgetto determine which map tile provider or base layer to initialize (default isNone).
- BaseGeometryWidget.geom_typeLink to this definition
The OpenGIS geometry type, generally set by the form field.
- BaseGeometryWidget.map_sridLink to this definition
SRID code used by the map (default is 4326).
- BaseGeometryWidget.display_rawLink to this definition
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_3dLink to this definition
Indicates if the widget supports edition of 3D data (default is
False).
- BaseGeometryWidget.template_nameLink to this definition
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 classesLink to this heading
BaseGeometryWidget
- class BaseGeometryWidgetLink to this definition
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_layerclass attribute.
OpenLayersWidget
- class OpenLayersWidgetLink to this definition
This is the default widget used by all GeoDjango form fields. Attributes are:
- base_layerLink to this definition
nasaWorldview
- template_nameLink to this definition
gis/openlayers.html.
- map_sridLink to this definition
3857
OpenLayersWidgetandOSMWidgetinclude theol.jsandol.cssfiles hosted on thecdn.jsdelivr.netcontent-delivery network. These files can be overridden by subclassing the widget and setting thejsandcssproperties of the innerMediaclass (see Assets as a static definition).
OSMWidget
- class OSMWidgetLink to this definition
This widget specialized
OpenLayersWidgetand uses an OpenStreetMap base layer to display geographic objects on. Attributes are:- base_layerLink to this definition
osm
- default_latLink to this definition
- default_lonLink to this definition
The default center latitude and longitude are
47and5, respectively, which is a location in eastern France.
- default_zoomLink to this definition
The default map zoom is
12.
The
OpenLayersWidgetnote about using external assets also applies here. See also this FAQ answer abouthttpsaccess to map tiles.
Customizing the base layer used in OpenLayers-based widgetsLink to this heading
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"]