1Class::DBI::FromCGI(3)User Contributed Perl DocumentationClass::DBI::FromCGI(3)
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NAME

6       Class::DBI::FromCGI - Update Class::DBI data using CGI::Untaint
7

SYNOPSIS

9         package Film;
10         use Class::DBI::FromCGI;
11         use base 'Class::DBI';
12         # set up as any other Class::DBI class.
13
14         __PACKAGE__->untaint_columns(
15           printable => [qw/Title Director/],
16           integer   => [qw/DomesticGross NumExplodingSheep/],
17           date      => [qw/OpeningDate/],
18         );
19
20         # Later on, over in another package ...
21
22         my $h = CGI::Untaint->new( ... );
23         my $film = Film->retrieve('Godfather II');
24            $film->update_from_cgi($h);
25
26         my $new_film = Film->create_from_cgi($h);
27
28         if (my %errors = $film->cgi_update_errors) {
29           while (my ($field, $problem) = each %errors) {
30             warn "Problem with $field: $problem\n";
31           }
32         }
33
34         # or
35         $film->update_from_cgi($h => @columns_to_update);
36
37         # or
38         $film->update_from_cgi($h => { ignore => \@cols_to_ignore,
39                                        required => \@cols_needed,
40                                        all => \@columns_which_may_be_empty });
41
42
43         my $how = $film->untaint_type('Title'); # printable
44

DESCRIPTION

46       Lots of times, Class::DBI is used in web-based applications. (In fact,
47       coupled with a templating system that allows you to pass objects, such
48       as Template::Toolkit, Class::DBI is very much your friend for these.)
49
50       And, as we all know, one of the most irritating things about writing
51       web-based applications is the monotony of writing much of the same
52       stuff over and over again. And, where there's monotony there's a
53       tendency to skip over stuff that we all know is really important, but
54       is a pain to write - like Taint Checking and sensible input validation.
55       (Especially as we can still show a 'working' application without it!).
56       So, we now have CGI::Untaint to take care of a lot of that for us.
57
58       It so happens that CGI::Untaint also plays well with Class::DBI.
59       Class::DBI::FromCGI is a little wrapper that ties these two together.
60

METHODS

62   untaint_columns
63       All you need to do is to 'use Class::DBI::FromCGI' in your class (or in
64       your local Class::DBI subclass that all your other classes inherit
65       from. You do do that, don't you?).
66
67       Then, in each class in which you want to use this, you declare how you
68       want to untaint each column:
69
70         __PACKAGE__->untaint_columns(
71           printable => [qw/Title Director/],
72           integer   => [qw/DomesticGross NumExplodingSheep/],
73           date      => [qw/OpeningDate/],
74         );
75
76       (where the keys are the CGI::Untaint package to be used, and the values
77       a listref of the relevant columns).
78
79   update_from_cgi
80       When you want to update based on the values coming in from a web-based
81       form, you just call:
82
83         $obj->update_from_cgi($h => @columns_to_update);
84
85       If every value passed in gets through the CGI::Untaint process, the
86       object will be updated (but not committed, in case you want to do
87       anything else with it). Otherwise the update will fail (there are no
88       partial updates), and $obj->cgi_update_errors will tell you what went
89       wrong (as a hash of problem field => error from CGI::Untaint).
90
91   create_from_cgi
92       Similarly, if you wish to create a new object, then you can call:
93
94         my $obj = Class->create_from_cgi($h => @columns_to_update);
95
96       If this fails, $obj will be a defined object, containing the errors, as
97       with an update, but will not contain the values submitted, nor have
98       been written to the database.
99
100   untaint_type
101         my $how = $film->untaint_type('Title'); # printable
102
103       This tells you how we're going to untaint a given column.
104
105   cgi_update_errors
106         if (my %errors = $film->cgi_update_errors) {
107           while (my ($field, $problem) = each %errors) {
108             warn "Problem with $field: $problem\n";
109           }
110         }
111
112       This returns a hash of any errors when updating. Despite its name it
113       also applies when inserting.
114

Column Auto-Detection

116       As Class::DBI knows all its columns, you don't even have to say what
117       columns you're interested in, unless it's a subset, as we can auto-fill
118       these:
119
120         $obj->update_from_cgi($h);
121
122       You can also specify columns which must be present, or columns to be
123       ignored even if they are present:
124
125         $film->update_from_cgi($h => {
126           all      => \@all_columns, # auto-filled if left blank
127           ignore   => \@cols_to_ignore,
128           required => \@cols_needed,
129         });
130
131       Doesn't this all make your life so much easier?
132

NOTE

134       Don't try to update the value of your primary key. Class::DBI doesn't
135       like that. If you try to do this it will be silently skipped.
136

ANOTHER NOTE

138       If you haven't set up any 'untaint_column' information for a column
139       which you later attempt to untaint, then we try to call
140       $self->column_type to ascertain the default handler to use. Currently
141       this will only use if you're using Class::DBI::mysql, and only for
142       certain column types.
143

SEE ALSO

145       Class::DBI. CGI::Untaint. Template.
146

AUTHOR

148       Tony Bowden
149

BUGS and QUERIES

151       Please direct all correspondence regarding this module to:
152         bug-Class-DBI-FromCGI@rt.cpan.org
153
155       Copyright (C) 2001-2005 Kasei. All rights reserved.
156
157       This module is free software; you can redistribute it and/or modify it
158       under the same terms as Perl itself.
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162perl v5.34.0                      2021-07-22            Class::DBI::FromCGI(3)
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