# perldoc > Data::FormValidator::Constraints::Upload ## NAME [Data::FormValidator::Constraints::Upload](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator%3A%3AConstraints%3A%3AUpload/markdown) - Validate File Uploads ## SYNOPSIS # Be sure to use a CGI.pm or [CGI::Simple](https://www.chedong.com/phpMan.php/perldoc/CGI%3A%3ASimple/markdown) object as the form # input when using this constraint my $q = CGI->new; use [Data::FormValidator::Constraints::Upload](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator%3A%3AConstraints%3A%3AUpload/markdown) qw( file_format file_max_bytes image_max_dimensions image_min_dimensions ); my $dfv = [Data::FormValidator](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator/markdown)->check($q,$my_profile); # In a [Data::FormValidator](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator/markdown) Profile: constraint_methods => { image_name => [ file_format(), [file_max_bytes(10)](https://www.chedong.com/phpMan.php/man/filemaxbytes/10/markdown), image_max_dimensions(200,200), image_min_dimensions(100,100), ], } ## DESCRIPTION Note: This is a new module is a new addition to [Data::FormValidator](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator/markdown) and is should be considered "Beta". These module is meant to be used in conjunction with the [Data::FormValidator](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator/markdown) 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 points to array references 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 meta() method of the [Data::FormValidator::Results](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator%3A%3AResults/markdown) object. The meta data added is "extension" and "mime_type". The MIME type of the file will first be tried to figured out by using the <[File::MMagic](https://www.chedong.com/phpMan.php/perldoc/File%3A%3AMMagic/markdown)> 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. NOTE: if we have to fall back to using the MIME type provided by the browser, we access it from the original *input* data and not the *filtered* data. This should only cause issue when you have used a filter to alter the type of file that was uploaded (e.g. image conversion). 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(1024)](https://www.chedong.com/phpMan.php/man/filemaxbytes/1024/markdown), # 1 k Calling this function sets some meta data which can be retrieved through the meta() method of the [Data::FormValidator::Results](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator%3A%3AResults/markdown) object. The meta data added is "bytes". 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 meta() method of the [Data::FormValidator::Results](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator%3A%3AResults/markdown) object. The meta data added is "width" and "height". 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 meta() method of the [Data::FormValidator::Results](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator%3A%3AResults/markdown) object. The meta data added is "width" and "height". BACKWARDS COMPATIBILITY 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 parameters by reference. It looks like this: validator_packages => [qw([Data::FormValidator::Constraints::Upload](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator%3A%3AConstraints%3A%3AUpload/markdown))], 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. ## SEE ALSO FileMetadata, [Data::FormValidator](https://www.chedong.com/phpMan.php/perldoc/Data%3A%3AFormValidator/markdown), CGI, perl ## AUTHOR Mark Stosberg, <> ## COPYRIGHT AND LICENSE 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.