1valtype::gs1::ean13(n) Validation types valtype::gs1::ean13(n)
2______________________________________________________________________________
6
8 valtype::gs1::ean13 - Validation for EAN13
9
11 package require Tcl 8.5
12 package require snit 2
14 package require valtype::common
16 package require valtype::gs1::ean13 ?1?
18 valtype::gs1::ean13 validate value
20 valtype::gs1::ean13 checkdigit value
22______________________________________________________________________________
24
26 This package implements a snit validation type for an EAN13.
27 A validation type is an object that can be used to validate Tcl values
29 of a particular kind. For example, snit::integer, a validation type
30 defined by the snit package is used to validate that a Tcl value is an
31 integer.
32 Every validation type has a validate method which is used to do the
34 validation. This method must take a single argument, the value to be
35 validated; further, it must do nothing if the value is valid, but throw
36 an error if the value is invalid:
37 valtype::gs1::ean13 validate .... ;# Does nothing
40 valtype::gs1::ean13 validate .... ;# Throws an error (bad EAN13).
41 The validate method will always return the validated value on success,
44 and throw the -errorcode INVALID on error, possibly with additional el‐
45 ements which provide more details about the problem.
46
48 The API provided by this package satisfies the specification of snit
49 validation types found in the documentation of Snit's Not Incr Tcl.
50 valtype::gs1::ean13 validate value
52 This method validates the value and returns it, possibly in a
53 canonical form, if it passes. If the value does not pass the
54 validation an error is thrown.
55 valtype::gs1::ean13 checkdigit value
57 This method computes a check digit for the value. Before doing
58 so it is validated, except for a checkdigit. If the value does
59 not pass the validation no check digit is calculated and an er‐
60 ror is thrown instead.
61
63 As said in the package description, the errors thrown by the commands
64 of this package in response to input validation failures use the -er‐
65 rorcode INVALID to distinguish themselves from package internal errors.
66 To provide more detailed information about why the validation failed
68 the -errorCode goes actually beyond that. First, it will contain a
69 code detailing the type itself. Here this is EAN13. This is then fol‐
70 lowed by values detailing the reason for the failure. The full set of
71 -errorCodes which can be thrown by this package are:
72 INVALID EAN13 CHARACTER
74 The input value contained one or more bad characters, i.e. char‐
75 acters which must not occur in the input for it to be an EAN13.
76 INVALID EAN13 CHECK-DIGIT
78 The check digit of the input value is wrong. This usually sig‐
79 nals a data-entry error, with digits transposed, forgotten, etc.
80 Of course, th input may be an outright fake too.
81 INVALID EAN13 LENGTH
83 The input value is of the wrong length to be an EAN13.
84
86 This document, and the package it describes, will undoubtedly contain
87 bugs and other problems. Please report such in the category valtype of
88 the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
89 also report any ideas for enhancements you may have for either package
90 and/or documentation.
91 When proposing code changes, please provide unified diffs, i.e the out‐
93 put of diff -u.
94 Note further that attachments are strongly preferred over inlined
96 patches. Attachments can be made by going to the Edit form of the
97 ticket immediately after its creation, and then using the left-most
98 button in the secondary navigation bar.
99
101 Checking, EAN, EAN13, European Article Number, International Article
102 Number, Testing, Type checking, Validation, Value checking, isA
103
105 Validation, Type checking
106
108 Copyright (c) 2011 Andreas Kupries <andreas_kupries@users.sourceforge.net>
109tcllib 1 valtype::gs1::ean13(n)