1valtype::isbn(n) Validation types valtype::isbn(n)
2______________________________________________________________________________
6
8 valtype::isbn - Validation for ISBN
9
11 package require Tcl 8.5
12 package require snit 2
14 package require valtype::common
16 package require valtype::isbn ?1?
18 valtype::isbn validate value
20 valtype::isbn checkdigit value
22 valtype::isbn 13of value
24______________________________________________________________________________
26
28 This package implements a snit validation type for an ISBN.
29 A validation type is an object that can be used to validate Tcl values
31 of a particular kind. For example, snit::integer, a validation type
32 defined by the snit package is used to validate that a Tcl value is an
33 integer.
34 Every validation type has a validate method which is used to do the
36 validation. This method must take a single argument, the value to be
37 validated; further, it must do nothing if the value is valid, but throw
38 an error if the value is invalid:
39 valtype::isbn validate .... ;# Does nothing
42 valtype::isbn validate .... ;# Throws an error (bad ISBN).
43 The validate method will always return the validated value on success,
46 and throw the -errorcode INVALID on error, possibly with additional
47 elements which provide more details about the problem.
48
50 The API provided by this package satisfies the specification of snit
51 validation types found in the documentation of Snit's Not Incr Tcl.
52 valtype::isbn validate value
54 This method validates the value and returns it, possibly in a
55 canonical form, if it passes. If the value does not pass the
56 validation an error is thrown.
57 valtype::isbn checkdigit value
59 This method computes a check digit for the value. Before doing
60 so it is validated, except for a checkdigit. If the value does
61 not pass the validation no check digit is calculated and an
62 error is thrown instead.
63 valtype::isbn 13of value
65 This method expects an old-style 10-digit ISBN and returns the
66 canonical modern 13-digit ISBN. This is used by validate to
67 canonicalize the input, so that all parts of the system after
68 the validation can expect to work with modern 13-digit ISBNs.
69
71 As said in the package description, the errors thrown by the commands
72 of this package in response to input validation failures use the
73 -errorcode INVALID to distinguish themselves from package internal
74 errors.
75 To provide more detailed information about why the validation failed
77 the -errorCode goes actually beyond that. First, it will contain a
78 code detailing the type itself. Here this is ISBN. This is then fol‐
79 lowed by values detailing the reason for the failure. The full set of
80 -errorCodes which can be thrown by this package are:
81 INVALID ISBN CHARACTER
83 The input value contained one or more bad characters, i.e. char‐
84 acters which must not occur in the input for it to be an ISBN.
85 INVALID ISBN CHECK-DIGIT
87 The check digit of the input value is wrong. This usually sig‐
88 nals a data-entry error, with digits transposed, forgotten, etc.
89 Of course, th input may be an outright fake too.
90 INVALID ISBN LENGTH
92 The input value is of the wrong length to be an ISBN.
93
95 This document, and the package it describes, will undoubtedly contain
96 bugs and other problems. Please report such in the category valtype of
97 the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
98 also report any ideas for enhancements you may have for either package
99 and/or documentation.
100 When proposing code changes, please provide unified diffs, i.e the out‐
102 put of diff -u.
103 Note further that attachments are strongly preferred over inlined
105 patches. Attachments can be made by going to the Edit form of the
106 ticket immediately after its creation, and then using the left-most
107 button in the secondary navigation bar.
108
110 Book Number, Checking, EAN, EAN13, European Article Number, ISBN,
111 International Article Number, International Standard Book Number, Test‐
112 ing, Type checking, Validation, Value checking, isA
113
115 Validation, Type checking
116
118 Copyright (c) 2011 Andreas Kupries <andreas_kupries@users.sourceforge.net>
119tcllib 1 valtype::isbn(n)