spatial.py

# encoding: utf-8

from ckan.common import config
import json
import urllib2

log = __import__('logging').getLogger(__name__)


class Spatial(object):
    def __init__(self, uri, text):
        self.uri = uri
        self.text = text


class SpatialRegister(object):
    def __init__(self):
        spatial_url = config.get('ckanext.odsh.spatial.mapping', None)
        if spatial_url:
            self.load_spatial(spatial_url)
        else:
            default_spatial_dict = dict()
            self._create_spatial_list(default_spatial_dict)

    def load_spatial(self, spatial_url):
        try:
            response = urllib2.urlopen(spatial_url)
            response_body = response.read()
        except Exception as inst:
            msg = "Couldn't connect to spatial service %r: %s" % (spatial_url, inst)
            raise Exception(msg)
        try:
            spatial_data = json.loads(response_body)
        except Exception as inst:
            msg = "Couldn't read response from spatial service %r: %s" % (response_body, inst)
            raise Exception(msg)
        self._create_spatial_list(spatial_data, spatial_url)

    def _create_spatial_list(self, spatial_data, spatial_url=''):
        if isinstance(spatial_data, dict):
            self.spatials = list()
            for entity in spatial_data:
                self.spatials.append(Spatial(entity, spatial_data[entity]['spatial_text']))
        else:
            msg = "Spatials at %s must be dictionary(json)" % spatial_url
            raise ValueError(msg)

    def __getitem__(self, key, default=Exception):
        for spatial in self.spatials:
            if key == spatial.uri:
                return spatial
            if default != Exception:
                return default
            else:
                raise KeyError("Spatial not found: %s" % key)

    def values(self):
        return self.spatials