Fixed #5472 --Added OpenLayers-based widgets in contrib.gis

Largely inspired from django-floppyforms. Designed to not depend
on OpenLayers at code level.

django/contrib/gis/db/models/fields.py

@@ -44,6 +44,7 @@ class GeometryField(Field):
 
     # The OpenGIS Geometry name.
     geom_type = 'GEOMETRY'
+    form_class = forms.GeometryField
 
     # Geodetic units.
     geodetic_units = ('Decimal Degree', 'degree')
@@ -201,11 +202,14 @@ def db_type(self, connection):
         return connection.ops.geo_db_type(self)
 
     def formfield(self, **kwargs):
-        defaults = {'form_class' : forms.GeometryField,
+        defaults = {'form_class' : self.form_class,
                     'geom_type' : self.geom_type,
                     'srid' : self.srid,
                     }
         defaults.update(kwargs)
+        if (self.dim > 2 and not 'widget' in kwargs and
+                not getattr(defaults['form_class'].widget, 'supports_3d', False)):
+            defaults['widget'] = forms.Textarea
         return super(GeometryField, self).formfield(**defaults)
 
     def get_db_prep_lookup(self, lookup_type, value, connection, prepared=False):
@@ -267,28 +271,35 @@ def get_placeholder(self, value, connection):
 # The OpenGIS Geometry Type Fields
 class PointField(GeometryField):
     geom_type = 'POINT'
+    form_class = forms.PointField
     description = _("Point")
 
 class LineStringField(GeometryField):
     geom_type = 'LINESTRING'
+    form_class = forms.LineStringField
     description = _("Line string")
 
 class PolygonField(GeometryField):
     geom_type = 'POLYGON'
+    form_class = forms.PolygonField
     description = _("Polygon")
 
 class MultiPointField(GeometryField):
     geom_type = 'MULTIPOINT'
+    form_class = forms.MultiPointField
     description = _("Multi-point")
 
 class MultiLineStringField(GeometryField):
     geom_type = 'MULTILINESTRING'
+    form_class = forms.MultiLineStringField
     description = _("Multi-line string")
 
 class MultiPolygonField(GeometryField):
     geom_type = 'MULTIPOLYGON'
+    form_class = forms.MultiPolygonField
     description = _("Multi polygon")
 
 class GeometryCollectionField(GeometryField):
     geom_type = 'GEOMETRYCOLLECTION'
+    form_class = forms.GeometryCollectionField
     description = _("Geometry collection")

django/contrib/gis/forms/__init__.py

@@ -1,2 +1,5 @@
 from django.forms import *
-from django.contrib.gis.forms.fields import GeometryField
+from .fields import (GeometryField, GeometryCollectionField, PointField,
+    MultiPointField, LineStringField, MultiLineStringField, PolygonField,
+    MultiPolygonField)
+from .widgets import BaseGeometryWidget, OpenLayersWidget, OSMWidget

django/contrib/gis/forms/fields.py

@@ -9,6 +9,7 @@
 # While this couples the geographic forms to the GEOS library,
 # it decouples from database (by not importing SpatialBackend).
 from django.contrib.gis.geos import GEOSException, GEOSGeometry, fromstr
+from .widgets import OpenLayersWidget
 
 
 class GeometryField(forms.Field):
@@ -17,7 +18,8 @@ class GeometryField(forms.Field):
     accepted by GEOSGeometry is accepted by this form.  By default,
     this includes WKT, HEXEWKB, WKB (in a buffer), and GeoJSON.
     """
-    widget = forms.Textarea
+    widget = OpenLayersWidget
+    geom_type = 'GEOMETRY'
 
     default_error_messages = {
         'required' : _('No geometry value provided.'),
@@ -31,12 +33,13 @@ def __init__(self, **kwargs):
         # Pop out attributes from the database field, or use sensible
         # defaults (e.g., allow None).
         self.srid = kwargs.pop('srid', None)
-        self.geom_type = kwargs.pop('geom_type', 'GEOMETRY')
+        self.geom_type = kwargs.pop('geom_type', self.geom_type)
         if 'null' in kwargs:
             kwargs.pop('null', True)
             warnings.warn("Passing 'null' keyword argument to GeometryField is deprecated.",
                 DeprecationWarning, stacklevel=2)
         super(GeometryField, self).__init__(**kwargs)
+        self.widget.attrs['geom_type'] = self.geom_type
 
     def to_python(self, value):
         """
@@ -98,3 +101,31 @@ def _has_changed(self, initial, data):
         else:
             # Check for change of state of existence
             return bool(initial) != bool(data)
+
+
+class GeometryCollectionField(GeometryField):
+    geom_type = 'GEOMETRYCOLLECTION'
+
+
+class PointField(GeometryField):
+    geom_type = 'POINT'
+
+
+class MultiPointField(GeometryField):
+    geom_type = 'MULTIPOINT'
+
+
+class LineStringField(GeometryField):
+    geom_type = 'LINESTRING'
+
+
+class MultiLineStringField(GeometryField):
+    geom_type = 'MULTILINESTRING'
+
+
+class PolygonField(GeometryField):
+    geom_type = 'POLYGON'
+
+
+class MultiPolygonField(GeometryField):
+    geom_type = 'MULTIPOLYGON'

django/contrib/gis/forms/widgets.py

@@ -0,0 +1,112 @@
+from __future__ import unicode_literals
+
+import logging
+
+from django.conf import settings
+from django.contrib.gis import gdal
+from django.contrib.gis.geos import GEOSGeometry, GEOSException
+from django.forms.widgets import Widget
+from django.template import loader
+from django.utils import six
+from django.utils import translation
+
+logger = logging.getLogger('django.contrib.gis')
+
+
+class BaseGeometryWidget(Widget):
+    """
+    The base class for rich geometry widgets.
+    Renders a map using the WKT of the geometry.
+    """
+    geom_type = 'GEOMETRY'
+    map_srid = 4326
+    map_width = 600
+    map_height = 400
+    display_wkt = False
+
+    supports_3d = False
+    template_name = ''  # set on subclasses
+
+    def __init__(self, attrs=None):
+        self.attrs = {}
+        for key in ('geom_type', 'map_srid', 'map_width', 'map_height', 'display_wkt'):
+            self.attrs[key] = getattr(self, key)
+        if attrs:
+            self.attrs.update(attrs)
+
+    def render(self, name, value, attrs=None):
+        # If a string reaches here (via a validation error on another
+        # field) then just reconstruct the Geometry.
+        if isinstance(value, six.string_types):
+            try:
+                value = GEOSGeometry(value)
+            except (GEOSException, ValueError) as err:
+                logger.error(
+                    "Error creating geometry from value '%s' (%s)" % (
+                    value, err)
+                )
+                value = None
+
+        wkt = ''
+        if value:
+            # Check that srid of value and map match
+            if value.srid != self.map_srid:
+                try:
+                    ogr = value.ogr
+                    ogr.transform(self.map_srid)
+                    wkt = ogr.wkt
+                except gdal.OGRException as err:
+                    logger.error(
+                        "Error transforming geometry from srid '%s' to srid '%s' (%s)" % (
+                        value.srid, self.map_srid, err)
+                    )
+            else:
+                wkt = value.wkt
+
+        context = self.build_attrs(attrs,
+            name=name,
+            module='geodjango_%s' % name.replace('-','_'),  # JS-safe
+            wkt=wkt,
+            geom_type=gdal.OGRGeomType(self.attrs['geom_type']),
+            STATIC_URL=settings.STATIC_URL,
+            LANGUAGE_BIDI=translation.get_language_bidi(),
+        )
+        return loader.render_to_string(self.template_name, context)
+
+
+class OpenLayersWidget(BaseGeometryWidget):
+    template_name = 'gis/openlayers.html'
+    class Media:
+        js = (
+            'http://openlayers.org/api/2.11/OpenLayers.js',
+            'gis/js/OLMapWidget.js',
+        )
+
+
+class OSMWidget(BaseGeometryWidget):
+    """
+    An OpenLayers/OpenStreetMap-based widget.
+    """
+    template_name = 'gis/openlayers-osm.html'
+    default_lon = 5
+    default_lat = 47
+
+    class Media:
+        js = (
+            'http://openlayers.org/api/2.11/OpenLayers.js',
+            'http://www.openstreetmap.org/openlayers/OpenStreetMap.js',
+            'gis/js/OLMapWidget.js',
+        )
+
+    @property
+    def map_srid(self):
+        # Use the official spherical mercator projection SRID on versions
+        # of GDAL that support it; otherwise, fallback to 900913.
+        if gdal.HAS_GDAL and gdal.GDAL_VERSION >= (1, 7):
+            return 3857
+        else:
+            return 900913
+
+    def render(self, name, value, attrs=None):
+        return super(self, OSMWidget).render(name, value,
+            {'default_lon': self.default_lon, 'default_lat': self.default_lat})