Data::FormValidator::Constraints::Upload - Validate File Uploads

    # Be sure to use a CGI.pm or CGI::Simple object as the form
    # input when using this constraint
    my $q = new CGI;

        use Data::FormValidator::Constraints::Upload qw(
                        file_format
                        file_max_bytes
                    image_max_dimensions
                    image_min_dimensions
        );
    my $dfv = Data::FormValidator->check($q,$my_profile);

        # In a Data::FormValidator Profile:
        constraint_methods => {
                image_name => [
                        file_format(),
                        file_max_bytes(1),
                    image_max_dimensions(200,200),      
                    image_min_dimensions(100,100),
                 ],
        }

Note: This is a new module is a new addition to Data::FormValidator and is should be considered Beta.

These module is meant to be used in conjunction with the Data::FormValidator module to automate the task of validating uploaded files. The following validation routines are supplied.

To use any of them, the input data passed to Data::FormValidator must be a CGI.pm object.

file_format

This function checks the format of the file, based on the MIME type if it's available, and a case-insensitive version of the file extension otherwise. By default, it tries to validate JPEG, GIF and PNG images. The params are:

 optional hash reference of parameters. A key named I<mime_types> points to
 array refererences of valid values.

   file_format( mime_types => [qw!image/jpeg image/gif image/png!] );

Calling this function sets some meta data which can be retrieved through the CWmeta() method of the Data::FormValidator::Results object. The meta data added is CWextension and CWmime_type. The MIME type of the file will first be tried to figured out by using the <File::MMagic> module to examine the file. If that doesn't turn up a result, we'll use a MIME type from the browser if one has been provided. Otherwise, we give up. The extension we return is based on the MIME type we found, rather than trusting the one that was uploaded.

file_max_bytes

This function checks the maximum size of an uploaded file. By default, it checks to make sure files are smaller than 1 Meg. The params are:

 reference to max file size in bytes

        file_max_bytes(1), # 1 k

Calling this function sets some meta data which can be retrieved through the CWmeta() method of the Data::FormValidator::Results object. The meta data added is CWbytes.

image_max_dimensions

This function checks to make sure an uploaded image is no longer than some maximum dimensions. The params are:

 reference to max pixel width
 reference to max pixel height

    image_max_dimensions(200,200),

Calling this function sets some meta data which can be retrieved through the CWmeta() method of the Data::FormValidator::Results object. The meta data added is CWwidth and CWheight.

image_min_dimensions

This function checks to make sure an uploaded image is longer than some minimum dimensions. The params are:

 reference to min pixel width
 reference to min pixel height

    image_min_dimensions(100,100),

Calling this function sets some meta data which can be retrieved through the CWmeta() method of the Data::FormValidator::Results object. The meta data added is CWwidth and CWheight.

An older more awkward interface to the constraints in this module is still supported. To use it, you have to load the package with 'validator_packages', and call each constraint in a hashref style, passing the the parameters by reference. It looks like this:

        validator_packages => [qw(Data::FormValidator::Constraints::Upload)],
        constraints => {
                image_name => [
                        {
                        constraint_method => 'image_max_dimensions', 
                                params => [\200,\200],
                        }
                 ],
        }

I told you it was more awkward. That was before I grokked the magic of closures, which is what drives the current interface.

FileMetadata, Data::FormValidator, CGI, perl

Mark Stosberg, <mark@summersault.com>

Copyright 2003-2005 by Mark Stosberg

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.