Initial commit: Core packages

odoo-bringout-oca-ocb-base/odoo/tools/barcode.py

@@ -0,0 +1,54 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+import re
+
+
+def get_barcode_check_digit(numeric_barcode):
+    """ Computes and returns the barcode check digit. The used algorithm
+    follows the GTIN specifications and can be used by all compatible
+    barcode nomenclature, like as EAN-8, EAN-12 (UPC-A) or EAN-13.
+    https://www.gs1.org/sites/default/files/docs/barcodes/GS1_General_Specifications.pdf
+    https://www.gs1.org/services/how-calculate-check-digit-manually
+    :param numeric_barcode: the barcode to verify/recompute the check digit
+    :type numeric_barcode: str
+    :return: the number corresponding to the right check digit
+    :rtype: int
+    """
+    # Multiply value of each position by
+    # N1  N2  N3  N4  N5  N6  N7  N8  N9  N10 N11 N12 N13 N14 N15 N16 N17 N18
+    # x3  X1  x3  x1  x3  x1  x3  x1  x3  x1  x3  x1  x3  x1  x3  x1  x3  CHECKSUM
+    oddsum = evensum = 0
+    code = numeric_barcode[-2::-1]  # Remove the check digit and reverse the barcode.
+    # The CHECKSUM digit is removed because it will be recomputed and it must not interfer with
+    # the computation. Also, the barcode is inverted, so the barcode length doesn't matter.
+    # Otherwise, the digits' group (even or odd) could be different according to the barcode length.
+    for i, digit in enumerate(code):
+        if i % 2 == 0:
+            evensum += int(digit)
+        else:
+            oddsum += int(digit)
+    total = evensum * 3 + oddsum
+    return (10 - total % 10) % 10
+
+
+def check_barcode_encoding(barcode, encoding):
+    """ Checks if the given barcode is correctly encoded.
+    :return: True if the barcode string is encoded with the provided encoding.
+    :rtype: bool
+    """
+    encoding = encoding.lower()
+    if encoding == "any":
+        return True
+    barcode_sizes = {
+        'ean8': 8,
+        'ean13': 13,
+        'gtin14': 14,
+        'upca': 12,
+        'sscc': 18,
+    }
+    barcode_size = barcode_sizes[encoding]
+    return (encoding != 'ean13' or barcode[0] != '0') \
+           and len(barcode) == barcode_size \
+           and re.match(r"^\d+$", barcode) \
+           and get_barcode_check_digit(barcode) == int(barcode[-1])