1Workflow::Validator(3)User Contributed Perl DocumentationWorkflow::Validator(3)
2
3
4

NAME

6       Workflow::Validator - Ensure data are valid
7

VERSION

9       This documentation describes version 1.05 of this package
10

SYNOPSIS

12        # First declare the validator...
13        <validator name="DateValidator"
14                   class="MyApp::Validator::Date">
15          <param name="date_format" value="%Y-%m-%d %h:%m"/>
16        </validator>
17
18        # Then associate the validator with runtime data from the context...
19        <action name="MyAction">
20           <validator name="DateValidator">
21              <arg>$due_date</arg>
22           </validator>
23        </action>
24
25        # TODO: You can also inintialize and instantiate in one step if you
26        # don't need to centralize or reuse (does this work?)
27
28        <action name="MyAction">
29           <validator class="MyApp::Validator::Date">
30              <param name="date_format" value="%Y-%m-%d %h:%m"/>
31              <arg>$due_date</arg>
32           </validator>
33        </action>
34
35        # Then implement the logic
36
37        package MyApp::Validator::Date;
38
39        use strict;
40        use base qw( Workflow::Validator );
41        use DateTime::Format::Strptime;
42        use Workflow::Exception qw( configuration_error );
43
44        __PACKAGE__->mk_accessors( 'formatter' );
45
46        sub _init {
47            my ( $self, $params ) = @_;
48            unless ( $params->{date_format} ) {
49                configuration_error
50                    "You must define a value for 'date_format' in ",
51                    "declaration of validator ", $self->name;
52            }
53            if ( ref $params->{date_format} ) {
54                configuration_error
55                    "The value for 'date_format' must be a simple scalar in ",
56                    "declaration of validator ", $self->name;
57            }
58            my $formatter = DateTime::Format::Strptime->new(
59                                     pattern => $params->{date_format},
60                                     on_error => 'undef' );
61            $self->formatter( $formatter );
62        }
63
64        sub validate {
65            my ( $self, $wf, $date_string ) = @_;
66            my $fmt = $self->formatter;
67            my $date_object = $fmt->parse_datetime( $date_string );
68            unless ( $date_object ) {
69                validation_error
70                    "Date '$date_string' does not match pattern '", $fmt->pattern, "' ",
71                    "due to error '", $fmt->errstr, "'";
72            }
73        }
74

DESCRIPTION

76       Validators specified by 'validator_name' are looked up in the
77       Workflow::Factory which reads a separate configuration and generates
78       validators. (Generally all validators should be declared, but it is not
79       required.)
80
81       Validators are objects with a single public method, 'validate()' that
82       take as arguments a workflow object and a list of parameters. The
83       parameters are filled in by the workflow engine according to the
84       instantiation declaration in the Action.
85
86       The idea behind a validator is that it validates data but does not care
87       where it comes from.
88

SUBCLASSING

90   Strategy
91   Methods
92       init( \%params )
93
94       Called when the validator is first initialized. If you do not have
95       sufficient information in "\%params" you should throw an exception.
96
97       _init
98
99       This is a dummy method, please see "init".
100
101       validate( $workflow, $data )
102
103       Determine whether your $data is true or false. If necessary you can get
104       the application context information from the $workflow object.
105

107       Copyright (c) 2003-2004 Chris Winters. All rights reserved.
108
109       This library is free software; you can redistribute it and/or modify it
110       under the same terms as Perl itself.
111

AUTHORS

113       Chris Winters <chris@cwinters.com>
114
115
116
117perl v5.12.0                      2010-05-07            Workflow::Validator(3)
Impressum