NAME
CGI::Application::Plugin::ValidateQuery - lightweight query validation for CGI::Application
VERSION
Version 1.0.3
SYNOPSIS
use CGI::Application::ValidateQuery qw(validate_query
validate_query_config
:types);
sub setup {
my $self = shift;
$self->validate_query_config(
# define a page to show for invalid queries, or default to
# serving a plain, internal page
error_mode => 'my_invalid_query_run_mode',
log_level => 'notice',
extra_fields_optional => 0,
);
}
sub my_run_mode {
my $self = shift;
# validate the query and return a standard error page on failure.
$self->validate_query(
pet_id => SCALAR,
direction => { type => SCALAR, default => 'up' },
);
# go on with life...
}DESCRIPTION
This plugin is for small query validation tasks. For example, perhaps you link to a page where a "pet_id" is required, and you need to reality check that this exists or return essentially a generic error message to the user.
Even if your application generates the link, it may become altered through tampering, malware, or other unanticipated events.
This plugin uses Params::Validate to validate the query string. You can define your own error page to return on failure, or import a plain default one that we supply.
You may also define a log_level, if you do, we will also log each validation failure at the chosen level like this:
$self->log->$loglevel("Query validation failed: $@");CGI::Application::Plugin::LogDispatch is one plugin which implements this logging API.
validate_query
my %validated = $self->validate_query(
pet_id => SCALAR,
type => { type => SCALAR, default => 'food' },
log_level => 'critical', # optional
extra_fields_optional => 1 # optional, default is 0
);Validates $self->query using Params::Validate. If any required query param is missing or invalid, the run mode defined with validate_query_config will be used. If you don't want to supply one, you can import a plain error run mode--validate_query_error_mode that we provide. It will be returned by default. validate_query_config is usually called in setup(), or a in a project super-class.
If log_level is defined, it will override the the log level provided in validate_query_config and log a validation failure at that log level.
If extra_fields_optional is defined and true, any parameter found in $self->query not listed in the call to validate_query will be ignored by the check (in other words, it will be included in the profile passed to Params::Validate but marked only as optional). If this is all the validation you're performing, don't use this; this option is here for cases where, for example, a bunch of POST values are already being checked by something heavier like Data::FormValidator and you just want to check one or two GET values.
If you set a default for any parameter, the query will be modified with the new value.
The function, like Params::Validate::validate, returns the validated data.
IMPLENTATION NOTES
We re-export the constants provided in Params::Validate. They can be loaded using either the :all tag or by including the :types tag along with the validate_query methods. Using :all will import everything from both this module and from Params::Validate.
We set "local $Params::Validate::NO_VALIDATION = 0;" to be sure that Params::Validate works for us, even if is globally disabled.
To alter the application flow when validation fails, we set 'error_mode()' at the last minute, and then die, so the error mode is triggered. Other uses of error_mode() should continue to work as normal.
This module is intended to be use for simple query validation tasks, such as a link with query string with a small number of arguments. For larger validation tasks, especially for processing for submissions using Data::FormValidator is recommended, along with CGI::Application::Plugin::ValidateRMif you using CGI::Application.
FUTURE
This concept could be extended to all check values set through $self->param(), or through $ENV{PATH_INFO}.
This plugin does not handle file upload validations, and won't in the future.
Providing untainting is not a goal of this module, but if it's easy and if someone else provides a patch, perhaps support will be added. Params::Validate provides untainting functionality and may be useful.
AUTHOR
Nate Smith nate@summersault.com, Mark Stosberg mark@summersault.com
BUGS & ISSUES
Please report any bugs or feature requests to bug-cgi-application-plugin-validatequery at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=CGI-Application-Plugin-ValidateQuery. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
COPYRIGHT & LICENSE
Copyright 2009 Summersault, LLC., all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.