flectra/addons/barcodes/models/barcodes.py

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import logging
import re
2018-01-16 11:34:37 +01:00
from flectra import tools, models, fields, api, _
from flectra.exceptions import ValidationError
_logger = logging.getLogger(__name__)
UPC_EAN_CONVERSIONS = [
('none','Never'),
('ean2upc','EAN-13 to UPC-A'),
('upc2ean','UPC-A to EAN-13'),
('always','Always'),
]
class BarcodeNomenclature(models.Model):
_name = 'barcode.nomenclature'
name = fields.Char(string='Nomenclature Name', size=32, required=True, help='An internal identification of the barcode nomenclature')
rule_ids = fields.One2many('barcode.rule', 'barcode_nomenclature_id', string='Rules', help='The list of barcode rules')
upc_ean_conv = fields.Selection(UPC_EAN_CONVERSIONS, string='UPC/EAN Conversion', required=True, default='always',
help="UPC Codes can be converted to EAN by prefixing them with a zero. This setting determines if a UPC/EAN barcode should be automatically converted in one way or another when trying to match a rule with the other encoding.")
# returns the checksum of the ean13, or -1 if the ean has not the correct length, ean must be a string
def ean_checksum(self, ean):
code = list(ean)
if len(code) != 13:
return -1
oddsum = evensum = total = 0
code = code[:-1] # Remove checksum
for i in range(len(code)):
if i % 2 == 0:
evensum += int(code[i])
else:
oddsum += int(code[i])
total = oddsum * 3 + evensum
return int((10 - total % 10) % 10)
# returns the checksum of the ean8, or -1 if the ean has not the correct length, ean must be a string
def ean8_checksum(self,ean):
code = list(ean)
if len(code) != 8:
return -1
sum1 = int(ean[1]) + int(ean[3]) + int(ean[5])
sum2 = int(ean[0]) + int(ean[2]) + int(ean[4]) + int(ean[6])
total = sum1 + 3 * sum2
return int((10 - total % 10) % 10)
# returns true if the barcode is a valid EAN barcode
def check_ean(self, ean):
return re.match("^\d+$", ean) and self.ean_checksum(ean) == int(ean[-1])
# returns true if the barcode string is encoded with the provided encoding.
def check_encoding(self, barcode, encoding):
if encoding == 'ean13':
return len(barcode) == 13 and re.match("^\d+$", barcode) and self.ean_checksum(barcode) == int(barcode[-1])
elif encoding == 'ean8':
return len(barcode) == 8 and re.match("^\d+$", barcode) and self.ean8_checksum(barcode) == int(barcode[-1])
elif encoding == 'upca':
return len(barcode) == 12 and re.match("^\d+$", barcode) and self.ean_checksum("0"+barcode) == int(barcode[-1])
elif encoding == 'any':
return True
else:
return False
# Returns a valid zero padded ean13 from an ean prefix. the ean prefix must be a string.
def sanitize_ean(self, ean):
ean = ean[0:13]
ean = ean + (13-len(ean))*'0'
return ean[0:12] + str(self.ean_checksum(ean))
# Returns a valid zero padded UPC-A from a UPC-A prefix. the UPC-A prefix must be a string.
def sanitize_upc(self, upc):
return self.sanitize_ean('0'+upc)[1:]
# Checks if barcode matches the pattern
# Additionaly retrieves the optional numerical content in barcode
# Returns an object containing:
# - value: the numerical value encoded in the barcode (0 if no value encoded)
# - base_code: the barcode in which numerical content is replaced by 0's
# - match: boolean
def match_pattern(self, barcode, pattern):
match = {
"value": 0,
"base_code": barcode,
"match": False,
}
barcode = barcode.replace("\\", "\\\\").replace("{", '\{').replace("}", "\}").replace(".", "\.")
numerical_content = re.search("[{][N]*[D]*[}]", pattern) # look for numerical content in pattern
if numerical_content: # the pattern encodes a numerical content
num_start = numerical_content.start() # start index of numerical content
num_end = numerical_content.end() # end index of numerical content
value_string = barcode[num_start:num_end-2] # numerical content in barcode
whole_part_match = re.search("[{][N]*[D}]", numerical_content.group()) # looks for whole part of numerical content
decimal_part_match = re.search("[{N][D]*[}]", numerical_content.group()) # looks for decimal part
whole_part = value_string[:whole_part_match.end()-2] # retrieve whole part of numerical content in barcode
decimal_part = "0." + value_string[decimal_part_match.start():decimal_part_match.end()-1] # retrieve decimal part
if whole_part == '':
whole_part = '0'
match['value'] = int(whole_part) + float(decimal_part)
match['base_code'] = barcode[:num_start] + (num_end-num_start-2)*"0" + barcode[num_end-2:] # replace numerical content by 0's in barcode
match['base_code'] = match['base_code'].replace("\\\\", "\\").replace("\{", "{").replace("\}","}").replace("\.",".")
pattern = pattern[:num_start] + (num_end-num_start-2)*"0" + pattern[num_end:] # replace numerical content by 0's in pattern to match
match['match'] = re.match(pattern, match['base_code'][:len(pattern)])
return match
# Attempts to interpret an barcode (string encoding a barcode)
# It will return an object containing various information about the barcode.
# most importantly :
# - code : the barcode
# - type : the type of the barcode:
# - value : if the id encodes a numerical value, it will be put there
# - base_code : the barcode code with all the encoding parts set to zero; the one put on
# the product in the backend
def parse_barcode(self, barcode):
parsed_result = {
'encoding': '',
'type': 'error',
'code': barcode,
'base_code': barcode,
'value': 0,
}
rules = []
for rule in self.rule_ids:
rules.append({'type': rule.type, 'encoding': rule.encoding, 'sequence': rule.sequence, 'pattern': rule.pattern, 'alias': rule.alias})
for rule in rules:
cur_barcode = barcode
if rule['encoding'] == 'ean13' and self.check_encoding(barcode,'upca') and self.upc_ean_conv in ['upc2ean','always']:
cur_barcode = '0'+cur_barcode
elif rule['encoding'] == 'upca' and self.check_encoding(barcode,'ean13') and barcode[0] == '0' and self.upc_ean_conv in ['ean2upc','always']:
cur_barcode = cur_barcode[1:]
if not self.check_encoding(barcode,rule['encoding']):
continue
match = self.match_pattern(cur_barcode, rule['pattern'])
if match['match']:
if rule['type'] == 'alias':
barcode = rule['alias']
parsed_result['code'] = barcode
else:
parsed_result['encoding'] = rule['encoding']
parsed_result['type'] = rule['type']
parsed_result['value'] = match['value']
parsed_result['code'] = cur_barcode
if rule['encoding'] == "ean13":
parsed_result['base_code'] = self.sanitize_ean(match['base_code'])
elif rule['encoding'] == "upca":
parsed_result['base_code'] = self.sanitize_upc(match['base_code'])
else:
parsed_result['base_code'] = match['base_code']
return parsed_result
return parsed_result
class BarcodeRule(models.Model):
_name = 'barcode.rule'
_order = 'sequence asc'
name = fields.Char(string='Rule Name', size=32, required=True, help='An internal identification for this barcode nomenclature rule')
barcode_nomenclature_id = fields.Many2one('barcode.nomenclature', string='Barcode Nomenclature')
sequence = fields.Integer(string='Sequence', help='Used to order rules such that rules with a smaller sequence match first')
encoding = fields.Selection([
('any', _('Any')),
('ean13', 'EAN-13'),
('ean8', 'EAN-8'),
('upca', 'UPC-A'),
], string='Encoding', required=True, default='any', help='This rule will apply only if the barcode is encoded with the specified encoding')
type = fields.Selection([
('alias', _('Alias')),
('product', _('Unit Product'))
], string='Type', required=True, default='product')
pattern = fields.Char(string='Barcode Pattern', size=32, help="The barcode matching pattern", required=True, default='.*')
alias = fields.Char(string='Alias', size=32, default='0', help='The matched pattern will alias to this barcode', required=True)
@api.one
@api.constrains('pattern')
def _check_pattern(self):
p = self.pattern.replace("\\\\", "X").replace("\{", "X").replace("\}", "X")
findall = re.findall("[{]|[}]", p) # p does not contain escaped { or }
if len(findall) == 2:
if not re.search("[{][N]*[D]*[}]", p):
raise ValidationError(_("There is a syntax error in the barcode pattern ") + self.pattern + _(": braces can only contain N's followed by D's."))
elif re.search("[{][}]", p):
raise ValidationError(_("There is a syntax error in the barcode pattern ") + self.pattern + _(": empty braces."))
elif len(findall) != 0:
raise ValidationError(_("There is a syntax error in the barcode pattern ") + self.pattern + _(": a rule can only contain one pair of braces."))
elif p == '*':
raise ValidationError(_(" '*' is not a valid Regex Barcode Pattern. Did you mean '.*' ?"))