dynamic-views.py

from django.conf import settings
from django.http import HttpResponse
from geonode.layers.views import _resolve_layer, _PERMISSION_MSG_VIEW

import TileStache
import json

def get_config(layer):
    if 'datastore' not in settings.DATABASES:
        raise Exception()

    config_dict = {
     "layers":{
      layer.name:{
        "provider": {
            "class": "TileStache.Goodies.VecTiles:Provider",
            "kwargs":{
                "clip": False,
                "dbinfo": {
                    "user": settings.DATABASES['datastore']['USER'],
                    "password": settings.DATABASES['datastore']['PASSWORD'],
                    "database": settings.DATABASES['datastore']['NAME']
                },
                "queries": [
                    "SELECT *, id as __id__, ST_SetSRID(geom, 900913) as __geometry__ FROM %s" % layer.name
                ]
            }
          }
        }
      },
     "cache":{
          "name": "Disk",
          "path": "file://%s/tiles/" % settings.MEDIA_ROOT
      }
    }

    config = TileStache.Config.buildConfiguration(config_dict)

    return config.layers[layer.name]


def tiles(request, layer_name, z, x, y, extension):
    """
    Proxy to tilestache
    {X} - coordinate column.
    {Y} - coordinate row.
    {B} - bounding box.
    {Z} - zoom level.
    {S} - host.
    """
    layer = _resolve_layer(request, layer_name, 'layers.view_layer', _PERMISSION_MSG_VIEW)

    path_info = "%s/%s/%s/%s.%s" % (layer_name, z, x, y, extension)
    coord, extension = TileStache.splitPathInfo(path_info)[1:]
    mimetype, content = TileStache.getTile(get_config(layer), coord, extension)
    return HttpResponse(content, mimetype=mimetype)