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tryton/currency.py
T
2018-12-29 14:20:29 +01:00

247 lines
8.4 KiB
Python

# This file is part of Tryton. The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
import datetime
from decimal import Decimal, ROUND_HALF_EVEN
from sql import Window
from sql.functions import NthValue
from trytond.i18n import gettext
from trytond.model import (
ModelView, ModelSQL, DeactivableMixin, fields, Unique, Check)
from trytond.transaction import Transaction
from trytond.pool import Pool
from trytond.rpc import RPC
from trytond.pyson import Eval
from .exceptions import RateError
__all__ = ['Currency', 'Rate']
class Currency(DeactivableMixin, ModelSQL, ModelView):
'Currency'
__name__ = 'currency.currency'
name = fields.Char('Name', required=True, translate=True,
help="The main identifier of the currency.")
symbol = fields.Char('Symbol', size=10, required=True,
help="The symbol used for currency formating.")
code = fields.Char('Code', size=3, required=True,
help="The 3 chars ISO currency code.")
numeric_code = fields.Char('Numeric Code', size=3,
help="The 3 digits ISO currency code.")
rate = fields.Function(fields.Numeric('Current rate', digits=(12, 6)),
'get_rate')
rates = fields.One2Many('currency.currency.rate', 'currency', 'Rates',
help="Add floating exchange rates for the currency.")
rounding = fields.Numeric('Rounding factor', required=True,
digits=(12, Eval('digits', 6)), depends=['digits'],
help="The minimum amount which can be represented in this currency.")
digits = fields.Integer("Digits", required=True,
help="The number of digits to display after the decimal separator.")
@classmethod
def __setup__(cls):
super(Currency, cls).__setup__()
cls._order.insert(0, ('code', 'ASC'))
cls.__rpc__.update({
'compute': RPC(instantiate=slice(0, 3, 2)),
})
@classmethod
def __register__(cls, module_name):
super(Currency, cls).__register__(module_name)
table_h = cls.__table_handler__(module_name)
# Migration from 4.6: removal of monetary
for col in [
'mon_grouping', 'mon_decimal_point',
'p_sign_posn', 'n_sign_posn']:
table_h.not_null_action(col, 'remove')
@staticmethod
def default_rounding():
return Decimal('0.01')
@staticmethod
def default_digits():
return 2
@classmethod
def check_xml_record(cls, records, values):
return True
@classmethod
def search_global(cls, text):
for record, rec_name, icon in super(Currency, cls).search_global(text):
icon = icon or 'tryton-currency'
yield record, rec_name, icon
@classmethod
def search_rec_name(cls, name, clause):
currencies = None
field = None
for field in ('code', 'numeric_code'):
currencies = cls.search([(field,) + tuple(clause[1:])], limit=1)
if currencies:
break
if currencies:
return [(field,) + tuple(clause[1:])]
return [(cls._rec_name,) + tuple(clause[1:])]
@fields.depends('rates')
def on_change_with_rate(self):
now = datetime.date.today()
closer = datetime.date.min
res = Decimal('0.0')
for rate in self.rates or []:
date = getattr(rate, 'date', None) or now
if date <= now and date > closer:
res = rate.rate
closer = date
return res
@staticmethod
def get_rate(currencies, name):
'''
Return the rate at the date from the context or the current date
'''
Rate = Pool().get('currency.currency.rate')
Date = Pool().get('ir.date')
res = {}
date = Transaction().context.get('date', Date.today())
for currency in currencies:
rates = Rate.search([
('currency', '=', currency.id),
('date', '<=', date),
], limit=1, order=[('date', 'DESC')])
if rates:
res[currency.id] = rates[0].id
else:
res[currency.id] = 0
rate_ids = [x for x in res.values() if x]
rates = Rate.browse(rate_ids)
id2rate = {}
for rate in rates:
id2rate[rate.id] = rate
for currency_id in res.keys():
if res[currency_id]:
res[currency_id] = id2rate[res[currency_id]].rate
return res
def round(self, amount, rounding=ROUND_HALF_EVEN):
'Round the amount depending of the currency'
return (amount / self.rounding).quantize(Decimal('1.'),
rounding=rounding) * self.rounding
def is_zero(self, amount):
'Return True if the amount can be considered as zero for the currency'
return abs(self.round(amount)) < self.rounding
@classmethod
def compute(cls, from_currency, amount, to_currency, round=True):
'''
Take a currency and an amount
Return the amount to the new currency
Use the rate of the date of the context or the current date
'''
Date = Pool().get('ir.date')
Lang = Pool().get('ir.lang')
from_currency = cls(int(from_currency))
to_currency = cls(int(to_currency))
if to_currency == from_currency:
if round:
return to_currency.round(amount)
else:
return amount
if (not from_currency.rate) or (not to_currency.rate):
date = Transaction().context.get('date', Date.today())
if not from_currency.rate:
name = from_currency.name
else:
name = to_currency.name
lang = Lang.get()
raise RateError(gettext('currency.msg_no_rate',
currency=name,
date=lang.strftime(date)))
if round:
return to_currency.round(
amount * to_currency.rate / from_currency.rate)
else:
return amount * to_currency.rate / from_currency.rate
@classmethod
def currency_rate_sql(cls):
"Return a SQL query with currency, rate, start_date and end_date"
pool = Pool()
Rate = pool.get('currency.currency.rate')
transaction = Transaction()
database = transaction.database
rate = Rate.__table__()
if database.has_window_functions():
window = Window(
[rate.currency],
order_by=[rate.date.asc],
frame='ROWS', start=0, end=1)
# Use NthValue instead of LastValue to get NULL for the last row
end_date = NthValue(rate.date, 2, window=window)
else:
next_rate = Rate.__table__()
end_date = next_rate.select(
next_rate.date,
where=(next_rate.currency == rate.currency)
& (next_rate.date > rate.date),
order_by=[next_rate.date.asc],
limit=1)
query = (rate
.select(
rate.currency.as_('currency'),
rate.rate.as_('rate'),
rate.date.as_('start_date'),
end_date.as_('end_date'),
))
return query
class Rate(ModelSQL, ModelView):
'Rate'
__name__ = 'currency.currency.rate'
date = fields.Date('Date', required=True, select=True,
help="From when the rate applies.")
rate = fields.Numeric('Rate', digits=(12, 6), required=1,
help="The floating exchange rate used to convert the currency.")
currency = fields.Many2One('currency.currency', 'Currency',
ondelete='CASCADE',
help="The currency on which the rate applies.")
@classmethod
def __setup__(cls):
super(Rate, cls).__setup__()
t = cls.__table__()
cls._sql_constraints = [
('date_currency_uniq', Unique(t, t.date, t.currency),
'currency.msg_currency_unique_rate_date'),
('check_currency_rate', Check(t, t.rate >= 0),
'currency.msg_currency_rate_positive'),
]
cls._order.insert(0, ('date', 'DESC'))
@staticmethod
def default_date():
Date = Pool().get('ir.date')
return Date.today()
@classmethod
def check_xml_record(cls, records, values):
return True
def get_rec_name(self, name):
return str(self.date)