django1/docs/ref/contrib/gis/forms-api.txt

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===================
GeoDjango Forms API
===================
.. module:: django.contrib.gis.forms
:synopsis: 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 `Metacarta`_.
.. _OpenLayers: http://openlayers.org/
.. _Metacarta: http://www.metacarta.com/
Field arguments
===============
In addition to the regular :ref:`form field arguments <core-field-arguments>`,
GeoDjango form fields take the following optional arguments.
``srid``
~~~~~~~~
.. attribute:: 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``
~~~~~~~~~~~~~
.. attribute:: 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
============
.. module:: django.contrib.gis.widgets
:synopsis: GeoDjango widgets API.
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.
.. attribute:: BaseGeometryWidget.geom_type
The OpenGIS geometry type, generally set by the form field.
.. attribute:: BaseGeometryWidget.map_height
.. attribute:: BaseGeometryWidget.map_width
Height and width of the widget map (default is 400x600).
.. attribute:: BaseGeometryWidget.map_srid
SRID code used by the map (default is 4326).
.. attribute:: 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``).
.. attribute:: BaseGeometryWidget.supports_3d
Indicates if the widget supports edition of 3D data (default is ``False``).
.. attribute:: 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 :attr:`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 :class:`OSMWidget` use the ``openlayers.js`` file
hosted on the ``openlayers.org`` Web site. This works for basic usage
2014-02-23 01:30:28 +08:00
during development, but isn't appropriate 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 :ref:`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 https://cdnjs.com/. This will also allow
you to serve the JavaScript file(s) using the ``https`` protocol if needed.
.. _tailored to your needs: http://docs.openlayers.org/library/deploying.html
``OSMWidget``
.. class:: OSMWidget
This widget uses an OpenStreetMap base layer (Mapnik) to display geographic
objects on.
``template_name`` is ``gis/openlayers-osm.html``.
The :class:`OpenLayersWidget` note about JavaScript file hosting above also
applies here. See also this `FAQ answer`_ about ``https`` access to map
tiles.
.. _FAQ answer: https://help.openstreetmap.org/questions/10920/how-to-embed-a-map-in-my-https-site