def __init__(self, api_key, entity, timestamp, payload):
'''
Constructor
@param api_key: FIWARe API Key
@param entity: Entity name
@param timestamp: timestamp of data creation
@param payload: UltraLight payload to be transmitted to FIWARE IoT agent
'''
# Create service group the first time an object is created
if Efiware.CREATE_SERVICE_GROUP:
Efiware.CREATE_SERVICE_GROUP = False
try:
self.create_service_group(EfConfig.FIWARE_APIKEY,
EfConfig.FIWARE_ENTITY,
EfConfig.FIWARE_DATAMODEL)
except EfException as ex:
ex.show()
# Send UL packet
try:
url = EfConfig.FIWARE_UL_URL
params = {
"k": api_key,
"i": entity,
"t": timestamp.strftime("%Y-%m-%dT%H:%M:%SZ"),
"getCmd": 1
}
headers = {"Content-Type": "text/plain"}
client = EfHttpClient(headers, url, params, payload)
print(client)
client.post()
except:
raise EfException("Unable to post UL packet to FIWARE IoT agent")
def create_service_group(self, api_key, entity_type, data_model):
"""
Create service group on FIWARE CB
@param api_key: FIWARE API Key
@param entity_type: Entity type (FIWARE_ENTITY_OBSERVATION or FIWARE_ENTITY_POLLUTION)
@param data_model: List of correspondances between UL and NGSI nomenclatures
"""
## Post request
try:
url = EfConfig.FIWARE_SERVGROUP_URL
params = {}
headers = {
"Content-Type": "application/json",
"fiware-service": EfConfig.FIWARE_SERVICE,
"fiware-servicepath": "/" + entity_type
}
# Declare datamodels
attributes = []
for key, value in data_model.items():
if key in EfConfig.FIWARE_DATAMODEL_STRINGS:
attr = {"object_id": key, "name": value, "type": "String"}
else:
attr = {"object_id": key, "name": value, "type": "Number"}
attributes.append(attr)
# Add location geo:point attribute
location = {
"expression": "${@longitude}, ${@latitude}",
"name": "location",
"type": "geo:point"
}
attributes.append(location)
payload = {
"services": [{
"apikey": api_key,
"protocol": ["IoTA-UL"],
"cbroker": "http://orion:1026",
"entity_type": entity_type,
"resource": "/iot/d",
"attributes": attributes
}]
}
client = EfHttpClient(headers, url, params, json.dumps(payload))
client.post()
except:
raise EfException(
"Unable to create service group. Probably because it already exists"
)
def get(self):
"""
Run HTTP get request
"""
try:
result = requests.get(self.url,
headers=self.header,
params=self.parameters,
data=self.payload)
if result.status_code == 200:
reader = csv.DictReader(io.StringIO(result.text),
delimiter=',')
return reader
else:
raise EfException("Unable to reach server via HTTP. Status: " +
result.status_code + " . Reason: " +
result.reason)
except Exception as ex:
raise EfException(str(ex))
def post(self):
"""
Run HTTP post request
"""
try:
result = requests.post(self.url,
headers=self.header,
params=self.parameters,
data=self.payload)
if result.status_code in [200, 201]:
try:
return result.json()
except:
return result.text
else:
raise EfException("Unable to reach server via HTTP. Status: " +
result.status_code + " . Reason: " +
result.reason)
except Exception as ex:
raise EfException(str(ex))
def query(self, country, polluant):
'''
Query observation data
@param country: country code
@param polluant: polluant to be queried
@return ordered dictionary contained the requested information
'''
url = ""
try:
url = EfConfig.EEA_URL + "/" + country + "_" + polluant + ".csv"
headers = {"Content-type": "text/csv"}
client = EfHttpClient(headers, url)
print("Downloading from " + url + "...")
res = client.get()
stations = {}
for row in res:
station_code = row["station_code"]
ref_time = row["value_datetime_end"]
timestamp = datetime.strptime(ref_time, "%Y-%m-%d %H:%M:%S%z")
conc = row["value_numeric"]
# Retain only the latest reading from each station
update = True
if conc != '':
if station_code in stations:
ts = stations[station_code]["timestamp"]
if ts > timestamp:
update = False
if update:
lat = row["samplingpoint_y"]
lon = row["samplingpoint_x"]
measurement = {
"timestamp": timestamp,
"lat": lat,
"lon": lon,
EfConfig.POLLUTION_PARAMETERS[polluant]: conc
}
stations[station_code] = measurement
return stations
except:
raise EfException("Unable to get data URL from " + url)