1 from django.conf import settings

     2 from django.contrib.admin import ModelAdmin

     3 from django.contrib.gis.admin.widgets import OpenLayersWidget

     4 from django.contrib.gis.gdal import OGRGeomType

     5 from django.contrib.gis.db import models

     6 

     7 class GeoModelAdmin(ModelAdmin):

     8     """

     9     The administration options class for Geographic models. Map settings

    10     may be overloaded from their defaults to create custom maps.

    11     """

    12     # The default map settings that may be overloaded -- still subject

    13     # to API changes.

    14     default_lon = 0

    15     default_lat = 0

    16     default_zoom = 4

    17     display_wkt = False

    18     display_srid = False

    19     extra_js = []

    20     num_zoom = 18

    21     max_zoom = False

    22     min_zoom = False

    23     units = False

    24     max_resolution = False

    25     max_extent = False

    26     modifiable = True

    27     mouse_position = True

    28     scale_text = True

    29     layerswitcher = True

    30     scrollable = True

    31     admin_media_prefix = settings.ADMIN_MEDIA_PREFIX

    32     map_width = 600

    33     map_height = 400

    34     map_srid = 4326

    35     map_template = 'gis/admin/openlayers.html'

    36     openlayers_url = 'http://openlayers.org/api/2.6/OpenLayers.js'

    37     wms_url = 'http://labs.metacarta.com/wms/vmap0'

    38     wms_layer = 'basic'

    39     wms_name = 'OpenLayers WMS'

    40     debug = False

    41     widget = OpenLayersWidget

    42 

    43     def _media(self):

    44         "Injects OpenLayers JavaScript into the admin."

    45         media = super(GeoModelAdmin, self)._media()

    46         media.add_js([self.openlayers_url])

    47         media.add_js(self.extra_js)

    48         return media

    49     media = property(_media)

    50 

    51     def formfield_for_dbfield(self, db_field, **kwargs):

    52         """

    53         Overloaded from ModelAdmin so that an OpenLayersWidget is used

    54         for viewing/editing GeometryFields.

    55         """

    56         if isinstance(db_field, models.GeometryField):

    57             # Setting the widget with the newly defined widget.

    58             kwargs['widget'] = self.get_map_widget(db_field)

    59             return db_field.formfield(**kwargs)

    60         else:

    61             return super(GeoModelAdmin, self).formfield_for_dbfield(db_field, **kwargs)

    62 

    63     def get_map_widget(self, db_field):

    64         """

    65         Returns a subclass of the OpenLayersWidget (or whatever was specified

    66         in the `widget` attribute) using the settings from the attributes set 

    67         in this class.

    68         """

    69         is_collection = db_field._geom in ('MULTIPOINT', 'MULTILINESTRING', 'MULTIPOLYGON', 'GEOMETRYCOLLECTION')

    70         if is_collection:

    71             if db_field._geom == 'GEOMETRYCOLLECTION': collection_type = 'Any'

    72             else: collection_type = OGRGeomType(db_field._geom.replace('MULTI', ''))

    73         else:

    74             collection_type = 'None'

    75 

    76         class OLMap(self.widget):

    77             template = self.map_template

    78             geom_type = db_field._geom

    79             params = {'admin_media_prefix' : self.admin_media_prefix,

    80                       'default_lon' : self.default_lon,

    81                       'default_lat' : self.default_lat,

    82                       'default_zoom' : self.default_zoom,

    83                       'display_wkt' : self.debug or self.display_wkt,

    84                       'geom_type' : OGRGeomType(db_field._geom),

    85                       'field_name' : db_field.name,

    86                       'is_collection' : is_collection,

    87                       'scrollable' : self.scrollable,

    88                       'layerswitcher' : self.layerswitcher,

    89                       'collection_type' : collection_type,

    90                       'is_linestring' : db_field._geom in ('LINESTRING', 'MULTILINESTRING'),

    91                       'is_polygon' : db_field._geom in ('POLYGON', 'MULTIPOLYGON'),

    92                       'is_point' : db_field._geom in ('POINT', 'MULTIPOINT'),

    93                       'num_zoom' : self.num_zoom,

    94                       'max_zoom' : self.max_zoom,

    95                       'min_zoom' : self.min_zoom,

    96                       'units' : self.units, #likely shoud get from object

    97                       'max_resolution' : self.max_resolution,

    98                       'max_extent' : self.max_extent,

    99                       'modifiable' : self.modifiable,

   100                       'mouse_position' : self.mouse_position,

   101                       'scale_text' : self.scale_text,

   102                       'map_width' : self.map_width,

   103                       'map_height' : self.map_height,

   104                       'srid' : self.map_srid,

   105                       'display_srid' : self.display_srid,

   106                       'wms_url' : self.wms_url,

   107                       'wms_layer' : self.wms_layer,

   108                       'wms_name' : self.wms_name,

   109                       'debug' : self.debug,

   110                       }

   111         return OLMap

   112 

   113 # Using the Beta OSM in the admin requires the following:

   114 #  (1) The Google Maps Mercator projection needs to be added

   115 #      to your `spatial_ref_sys` table.  You'll need at least GDAL 1.5:

   116 #      >>> from django.contrib.gis.gdal import SpatialReference

   117 #      >>> from django.contrib.gis.utils import add_postgis_srs

   118 #      >>> add_postgis_srs(SpatialReference(900913)) # Adding the Google Projection 

   119 from django.contrib.gis import gdal

   120 if gdal.HAS_GDAL:

   121     class OSMGeoAdmin(GeoModelAdmin):

   122         map_template = 'gis/admin/osm.html'

   123         extra_js = ['http://openstreetmap.org/openlayers/OpenStreetMap.js']

   124         num_zoom = 20

   125         map_srid = 900913

   126         max_extent = '-20037508,-20037508,20037508,20037508'

   127         max_resolution = 156543.0339

   128         units = 'm'