# =================================================================
#
# Authors: Tom Kralidis <tomkralidis@gmail.com>
#
# Copyright (c) 2018 Tom Kralidis
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
# =================================================================
from collections import OrderedDict
import csv
import itertools
import logging
import os
from pygeoapi.provider.base import (BaseProvider, ProviderQueryError,
ProviderItemNotFoundError)
from pygeoapi.plugin import load_plugin
from pygeoapi.cql_exception import CQLException
LOGGER = logging.getLogger(__name__)
[docs]class CSVProvider(BaseProvider):
"""CSV provider"""
def __init__(self, provider_def):
"""
Initialize object
:param provider_def: provider definition
:returns: pygeoapi.providers.csv_.CSVProvider
"""
BaseProvider.__init__(self, provider_def)
self.geometry_x = provider_def['geometry']['x_field']
self.geometry_y = provider_def['geometry']['y_field']
self.fields = self.get_fields()
[docs] def get_fields(self):
"""
Get provider field information (names, types)
:returns: dict of fields
"""
LOGGER.debug('Treating all columns as string types')
with open(self.data) as ff:
LOGGER.debug('Serializing DictReader')
data_ = csv.DictReader(ff)
fields = {}
for f in data_.fieldnames:
fields[f] = 'string'
return fields
[docs] def _load(self, identifier=None):
"""
Load CSV data
:param identifier: feature id
"""
if os.path.exists(self.data):
with open(self.data) as ff:
LOGGER.debug('Serializing DictReader')
data_ = csv.DictReader(ff)
dataset = list(data_)
else:
dataset = None
return dataset
[docs] def query(self, startindex=0, limit=10, resulttype='results',
bbox=[], datetime=None, properties=[], sortby=[],
cql_expression=None, identifier=None):
"""
CSV query
:param startindex: starting record to return (default 0)
:param limit: number of records to return (default 10)
:param resulttype: return results or hit limit (default results)
:param bbox: bounding box [minx,miny,maxx,maxy]
:param datetime: temporal (datestamp or extent)
:param properties: list of tuples (name, value)
:param sortby: list of dicts (property, order)
:param cql_expression: string of cql filter expression
:param identifier: feature id
:returns: dict of GeoJSON FeatureCollection
"""
dataset = self._load(identifier=identifier)
found = False
result = None
feature_collection = {
'type': 'FeatureCollection',
'features': []
}
count = len(dataset)
if resulttype == 'hits' and not cql_expression:
LOGGER.debug('Returning hits only')
feature_collection['numberMatched'] = count
return feature_collection
LOGGER.debug('Slicing CSV rows')
for row in itertools.islice(dataset, 0, count):
feature = {'type': 'Feature'}
feature['id'] = row.pop(self.id_field)
feature['geometry'] = {
'type': 'Point',
'coordinates': [
float(row.pop(self.geometry_x)),
float(row.pop(self.geometry_y))
]
}
if self.properties:
feature['properties'] = OrderedDict()
for p in self.properties:
try:
feature['properties'][p] = row[p]
except KeyError as err:
LOGGER.error(err)
raise ProviderQueryError()
else:
feature['properties'] = row
if identifier is not None and feature['id'] == identifier:
found = True
result = feature
feature_collection['features'].append(feature)
feature_collection['numberMatched'] = \
len(feature_collection['features'])
if cql_expression:
try:
feature_list = feature_collection['features']
cql_handler = load_plugin('extensions',
{'name': 'CQL',
'cql_expression': cql_expression,
'feature_list': feature_list})
feature_list = cql_handler.cql_filter()
except Exception as err:
raise CQLException(err)
feature_collection['features'] = feature_list
feature_collection['numberMatched'] = len(feature_collection
['features'])
if resulttype == 'hits':
feature_collection['features'] = []
return feature_collection
feature_collection['features'] = \
feature_collection['features'][startindex:startindex + limit]
if identifier is not None and not found:
return None
elif identifier is not None and found:
return result
feature_collection['numberReturned'] = len(
feature_collection['features'])
return feature_collection
[docs] def get(self, identifier):
"""
query CSV id
:param identifier: feature id
:returns: dict of single GeoJSON feature
"""
item = self.query(identifier=identifier)
if item:
return item
else:
err = 'item {} not found'.format(identifier)
LOGGER.error(err)
raise ProviderItemNotFoundError(err)
def __repr__(self):
return '<CSVProvider> {}'.format(self.data)