from django.shortcuts import render
from datetime import datetime
from currencies.models import (ExchangeRate,
ExchangeRate_date,
ExchangeRate_name)
from currencies import exchange_rates
from django.http import JsonResponse
def currencies(request):
"""this function fetches the data from swiss national bank
evaluates if the values are already stored and
prepares a view all dynamicaly.
It can grow in terms of more Currencies over time automaticaly."""
message_offline = ''
# Namespaces
ns = {'rdf': 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
'none': 'http://purl.org/rss/1.0/',
'dc': 'http://purl.org/dc/elements/1.1/',
'dcterms': 'http://purl.org/dc/terms/',
'cb': 'http://www.cbwiki.net/wiki/index.php/Specification_1.2/'
}
SNB_URL = 'https://www.snb.ch/selector/de/mmr/exfeed/rss'
try:
urlsocket = exchange_rates.get_rss(SNB_URL)
except Exception as e:
print('currencies/views.currencies() get_rss() error:', e)
try:
rss_tree = exchange_rates.parse_rss(urlsocket)
except Exception as e:
print('currencies/views.currencies() parse_rss() error:', e)
try:
raw_data = exchange_rates.get_exchange_rate(rss_tree, ns)
except Exception as e:
print('currencies/views.currencies() get_exchange_rate() error:', e)
# because url seams to be not avalable we fetch a local file in root
# didgeridoo/rss to get some older currencies.
rss_tree = exchange_rates.pass_local_file()
message_offline = """
Are you offline? - useing stored currencies.
This does not efect you, but your purchase prices will be
recalculated as soon as you submit your Order.
"""
try:
raw_data = exchange_rates.get_exchange_rate(rss_tree, ns)
except Exception as e:
print("""currencies/views.currencies()
get_exchange_rate.pass_local_file() error:""", e)
today = datetime.now().strftime("%Y-%m-%d")
message_no = "Already querried: "
length_of_message_no = len(message_no)
message_yes = " Updated successfully: "
length_of_message_yes = len(message_yes)
# raw_data can be empty. In this case skip:
if raw_data:
for one_obj_of_list in raw_data:
for exchange_rate_of_one_day in one_obj_of_list:
date = exchange_rate_of_one_day['date']
currency = exchange_rate_of_one_day['currency']
exchangerate = exchange_rate_of_one_day['exchangerate']
# check for already existing exrates per day and add
# to message that its already been saved.
if ExchangeRate.objects.filter(
date__date=date,
name__name=currency):
message_no += currency + ' on ' + date + ", "
else:
if ExchangeRate_date.objects.filter(date=date)[:1]:
# if data and currency is not yet present, save it.
try:
# A: https://stackoverflow.com/a/27802801/4061870
# lustigerweise gibt .values() den value und die id
# zurück. Ohne .values() gibts nur den "value"
date_dict = ExchangeRate_date.objects.filter(
date=date).values()
except Exception as e:
print('currencies/views/exdate_exists \
%s (%s) on %s'
% (e, type(e), today))
else:
try:
exdate = ExchangeRate_date.objects.create(
date=date)
exdate.save()
except Exception as e:
print('currencies/views/exdate_not_exists \
%s (%s) for %s'
% (e, type(e), date))
if ExchangeRate_name.objects.filter(
name=currency)[:1]:
# if data and currency is not yet present, save it.
try:
name_dict = ExchangeRate_name.objects.filter(
name=currency).values()
except Exception as e:
print('currencies/views/exname_exists \
%s (%s) on %s'
% (e, type(e), currency))
else:
try:
exname = ExchangeRate_name.objects.create(
name=currency)
exname.save()
except Exception as e:
print('currencies/views/exname_not_exists \
%s (%s) on %s'
% (e, type(e), currency))
try:
# save item to where id's match.
exrate = ExchangeRate.objects.create(
# name_id=name_id,
name_id=ExchangeRate_name.objects.get(
name=currency).id,
# date_id=date_id,
date_id=ExchangeRate_date.objects.get(
date=date).id,
exchange_rate_to_chf=exchangerate,
)
exrate.save()
message_yes += currency + ' on ' + date + ", "
except Exception as e:
print('currencies/views/exrate_create \
%s (%s) on %s for %s'
% (e, type(e), currency, date))
# prepare messages:
# python can not swap a char insinde a sting so i have
# to invert and swap and then invert back:
message_no = message_no[::-1] # invert the string
message_no = message_no.replace(",", "!", 1) # replace first , with !
message_no = message_no[::-1] # invert the string back
message_yes = message_yes[::-1] # invert the string
message_yes = message_yes.replace(",", "!", 1) # replace f. , with !
message_yes = message_yes[::-1] # invert the string back
# here we evaluate what kind of message is valid:
if len(message_no) > length_of_message_no\
and len(message_yes) > length_of_message_yes:
message = message_offline + message_no + message_yes
elif len(message_no) > 24:
message = message_offline + message_no
elif len(message_yes) > 18:
message = message_offline + message_yes
elif datetime.datetime.today().isoweekday() == 6:
message = """Die Abfrage wurde ohne ergebniss beendet.
Es ist Samstag, die SNB publiziert nur an Arbeitstagen
neue Kurse...
"""
elif datetime.datetime.today().isoweekday() == 7:
message = """Die Abfrage wurde ohne ergebniss beendet.
Es ist Sonntag, die SNB publiziert nur an Arbeitstagen
neue Kurse...
"""
else:
message = """Die Abfrage wurde ohne ergebniss beendet.
"""
# know we can query our data for presentaton:
ordered_currency_list = ExchangeRate.objects.order_by('name', 'date')
# and publish it on template:
return render(request,
'currencies/index.html',
{'ordered_currency_list': ordered_currency_list,
'message': message})