Class::DBI::FromCGI(3)User Contributed Perl DocumentatioClass::DBI::FromCGI(3)NAMEClass::DBI::FromCGI - Update Class::DBI data using CGI::Untaint
SYNOPSIS
package Film;
use Class::DBI::FromCGI;
use base 'Class::DBI';
# set up as any other Class::DBI class.
__PACKAGE__->untaint_columns(
printable => [qw/Title Director/],
integer => [qw/DomesticGross NumExplodingSheep/],
date => [qw/OpeningDate/],
);
# Later on, over in another package ...
my $h = CGI::Untaint->new( ... );
my $film = Film->retrieve('Godfather II');
$film->update_from_cgi($h);
my $new_film = Film->create_from_cgi($h);
if (my %errors = $film->cgi_update_errors) {
while (my ($field, $problem) = each %errors) {
warn "Problem with $field: $problem\n";
}
}
# or
$film->update_from_cgi($h => @columns_to_update);
# or
$film->update_from_cgi($h => { ignore => \@cols_to_ignore,
required => \@cols_needed,
all => \@columns_which_may_be_empty });
my $how = $film->untaint_type('Title'); # printable
DESCRIPTION
Lots of times, Class::DBI is used in web-based applications. (In fact,
coupled with a templating system that allows you to pass objects, such
as Template::Toolkit, Class::DBI is very much your friend for these.)
And, as we all know, one of the most irritating things about writing
web-based applications is the monotony of writing much of the same
stuff over and over again. And, where there's monotony there's a
tendency to skip over stuff that we all know is really important, but
is a pain to write - like Taint Checking and sensible input validation.
(Especially as we can still show a 'working' application without it!).
So, we now have CGI::Untaint to take care of a lot of that for us.
It so happens that CGI::Untaint also plays well with Class::DBI.
Class::DBI::FromCGI is a little wrapper that ties these two together.
METHODS
untaint_columns
All you need to do is to 'use Class::DBI::FromCGI' in your class (or in
your local Class::DBI subclass that all your other classes inherit
from. You do do that, don't you?).
Then, in each class in which you want to use this, you declare how you
want to untaint each column:
__PACKAGE__->untaint_columns(
printable => [qw/Title Director/],
integer => [qw/DomesticGross NumExplodingSheep/],
date => [qw/OpeningDate/],
);
(where the keys are the CGI::Untaint package to be used, and the values
a listref of the relevant columns).
update_from_cgi
When you want to update based on the values coming in from a web-based
form, you just call:
$obj->update_from_cgi($h => @columns_to_update);
If every value passed in gets through the CGI::Untaint process, the
object will be updated (but not committed, in case you want to do
anything else with it). Otherwise the update will fail (there are no
partial updates), and $obj->cgi_update_errors will tell you what went
wrong (as a hash of problem field => error from CGI::Untaint).
create_from_cgi
Similarly, if you wish to create a new object, then you can call:
my $obj = Class->create_from_cgi($h => @columns_to_update);
If this fails, $obj will be a defined object, containing the errors, as
with an update, but will not contain the values submitted, nor have
been written to the database.
untaint_type
my $how = $film->untaint_type('Title'); # printable
This tells you how we're going to untaint a given column.
cgi_update_errors
if (my %errors = $film->cgi_update_errors) {
while (my ($field, $problem) = each %errors) {
warn "Problem with $field: $problem\n";
}
}
This returns a hash of any errors when updating. Despite its name it
also applies when inserting.
Column Auto-Detection
As Class::DBI knows all its columns, you don't even have to say what
columns you're interested in, unless it's a subset, as we can auto-fill
these:
$obj->update_from_cgi($h);
You can also specify columns which must be present, or columns to be
ignored even if they are present:
$film->update_from_cgi($h => {
all => \@all_columns, # auto-filled if left blank
ignore => \@cols_to_ignore,
required => \@cols_needed,
});
Doesn't this all make your life so much easier?
NOTE
Don't try to update the value of your primary key. Class::DBI doesn't
like that. If you try to do this it will be silently skipped.
ANOTHER NOTE
If you haven't set up any 'untaint_column' information for a column
which you later attempt to untaint, then we try to call
$self->column_type to ascertain the default handler to use. Currently
this will only use if you're using Class::DBI::mysql, and only for
certain column types.
SEE ALSO
Class::DBI. CGI::Untaint. Template.
AUTHOR
Tony Bowden
BUGS and QUERIES
Please direct all correspondence regarding this module to:
bug-Class-DBI-FromCGI@rt.cpan.org
COPYRIGHT
Copyright (C) 2001-2005 Kasei. All rights reserved.
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.1 2005-10-04 Class::DBI::FromCGI(3)
