+
−from django.conf import settings
+
−from django.contrib.admin import ModelAdmin
+
−from django.contrib.gis.admin.widgets import OpenLayersWidget
+
−from django.contrib.gis.gdal import OGRGeomType
+
−from django.contrib.gis.db import models
+
−
+
−class GeoModelAdmin(ModelAdmin):
+
−    """
+
−    The administration options class for Geographic models. Map settings
+
−    may be overloaded from their defaults to create custom maps.
+
−    """
+
−    # The default map settings that may be overloaded -- still subject
+
−    # to API changes.
+
−    default_lon = 0
+
−    default_lat = 0
+
−    default_zoom = 4
+
−    display_wkt = False
+
−    display_srid = False
+
−    extra_js = []
+
−    num_zoom = 18
+
−    max_zoom = False
+
−    min_zoom = False
+
−    units = False
+
−    max_resolution = False
+
−    max_extent = False
+
−    modifiable = True
+
−    mouse_position = True
+
−    scale_text = True
+
−    layerswitcher = True
+
−    scrollable = True
+
−    admin_media_prefix = settings.ADMIN_MEDIA_PREFIX
+
−    map_width = 600
+
−    map_height = 400
+
−    map_srid = 4326
+
−    map_template = 'gis/admin/openlayers.html'
+
−    openlayers_url = 'http://openlayers.org/api/2.6/OpenLayers.js'
+
−    wms_url = 'http://labs.metacarta.com/wms/vmap0'
+
−    wms_layer = 'basic'
+
−    wms_name = 'OpenLayers WMS'
+
−    debug = False
+
−    widget = OpenLayersWidget
+
−
+
−    def _media(self):
+
−        "Injects OpenLayers JavaScript into the admin."
+
−        media = super(GeoModelAdmin, self)._media()
+
−        media.add_js([self.openlayers_url])
+
−        media.add_js(self.extra_js)
+
−        return media
+
−    media = property(_media)
+
−
+
−    def formfield_for_dbfield(self, db_field, **kwargs):
+
−        """
+
−        Overloaded from ModelAdmin so that an OpenLayersWidget is used
+
−        for viewing/editing GeometryFields.
+
−        """
+
−        if isinstance(db_field, models.GeometryField):
+
−            # Setting the widget with the newly defined widget.
+
−            kwargs['widget'] = self.get_map_widget(db_field)
+
−            return db_field.formfield(**kwargs)
+
−        else:
+
−            return super(GeoModelAdmin, self).formfield_for_dbfield(db_field, **kwargs)
+
−
+
−    def get_map_widget(self, db_field):
+
−        """
+
−        Returns a subclass of the OpenLayersWidget (or whatever was specified
+
−        in the `widget` attribute) using the settings from the attributes set 
+
−        in this class.
+
−        """
+
−        is_collection = db_field._geom in ('MULTIPOINT', 'MULTILINESTRING', 'MULTIPOLYGON', 'GEOMETRYCOLLECTION')
+
−        if is_collection:
+
−            if db_field._geom == 'GEOMETRYCOLLECTION': collection_type = 'Any'
+
−            else: collection_type = OGRGeomType(db_field._geom.replace('MULTI', ''))
+
−        else:
+
−            collection_type = 'None'
+
−
+
−        class OLMap(self.widget):
+
−            template = self.map_template
+
−            geom_type = db_field._geom
+
−            params = {'admin_media_prefix' : self.admin_media_prefix,
+
−                      'default_lon' : self.default_lon,
+
−                      'default_lat' : self.default_lat,
+
−                      'default_zoom' : self.default_zoom,
+
−                      'display_wkt' : self.debug or self.display_wkt,
+
−                      'geom_type' : OGRGeomType(db_field._geom),
+
−                      'field_name' : db_field.name,
+
−                      'is_collection' : is_collection,
+
−                      'scrollable' : self.scrollable,
+
−                      'layerswitcher' : self.layerswitcher,
+
−                      'collection_type' : collection_type,
+
−                      'is_linestring' : db_field._geom in ('LINESTRING', 'MULTILINESTRING'),
+
−                      'is_polygon' : db_field._geom in ('POLYGON', 'MULTIPOLYGON'),
+
−                      'is_point' : db_field._geom in ('POINT', 'MULTIPOINT'),
+
−                      'num_zoom' : self.num_zoom,
+
−                      'max_zoom' : self.max_zoom,
+
−                      'min_zoom' : self.min_zoom,
+
−                      'units' : self.units, #likely shoud get from object
+
−                      'max_resolution' : self.max_resolution,
+
−                      'max_extent' : self.max_extent,
+
−                      'modifiable' : self.modifiable,
+
−                      'mouse_position' : self.mouse_position,
+
−                      'scale_text' : self.scale_text,
+
−                      'map_width' : self.map_width,
+
−                      'map_height' : self.map_height,
+
−                      'srid' : self.map_srid,
+
−                      'display_srid' : self.display_srid,
+
−                      'wms_url' : self.wms_url,
+
−                      'wms_layer' : self.wms_layer,
+
−                      'wms_name' : self.wms_name,
+
−                      'debug' : self.debug,
+
−                      }
+
−        return OLMap
+
−
+
−# Using the Beta OSM in the admin requires the following:
+
−#  (1) The Google Maps Mercator projection needs to be added
+
−#      to your `spatial_ref_sys` table.  You'll need at least GDAL 1.5:
+
−#      >>> from django.contrib.gis.gdal import SpatialReference
+
−#      >>> from django.contrib.gis.utils import add_postgis_srs
+
−#      >>> add_postgis_srs(SpatialReference(900913)) # Adding the Google Projection 
+
−from django.contrib.gis import gdal
+
−if gdal.HAS_GDAL:
+
−    class OSMGeoAdmin(GeoModelAdmin):
+
−        map_template = 'gis/admin/osm.html'
+
−        extra_js = ['http://openstreetmap.org/openlayers/OpenStreetMap.js']
+
−        num_zoom = 20
+
−        map_srid = 900913
+
−        max_extent = '-20037508,-20037508,20037508,20037508'
+
−        max_resolution = 156543.0339
+
−        units = 'm'