NAME

Test::CGI::Multipart - Test posting of multi-part form data

VERSION

This document describes Test::CGI::Multipart version 0.0.1

SYNOPSIS

  use Test::CGI::Multipart;

  my $tcm = Test::CGI::Multipart;

  # specify the form parameters
  $tcm->set_param(name='email',value=>'jim@hacker.com');
  $tcm->set_param(name=>'pets',value=> ['Rex', 'Oscar', 'Bidgie', 'Fish']);
  $tcm->set_param(name=>'first_name',value=>'Jim');
  $tcm->set_param(name=>'last_name',value=>'Hacker');
  $tcm->upload_file(
      name=>'file1',
      file=>'made_up_filename.txt',
      value=>$content
  );
  $tcm->upload_file(
      name=>'file1',
      file=>'made_up_filename.blah',
      value=>$content_blah,
      type=>'application/blah'
  );

  # Behind the scenes this will fake the browser and web server behaviour
  # with regard to environment variables, MIME format and standard input.
  my $cgi = $tcm->create_cgi;

  # Okay now we have a CGI object which we can pass into the code 
  # that needs testing and run the form handling various tests.

DESCRIPTION

It is quite difficult to write test code to capture the behaviour 
of CGI or similar objects handling forms that include a file upload.
Such code needs to harvest the parameters, build file content in MIME
format, set the environment variables accordingly and pump it into the 
the standard input of the required CGI object. This module provides
simple methods so that having prepared suitable content, the test script
can simulate the submission of webforms including file uploads.

However we also recognize that a test script is not always the best place
to prepare content. Rather a test script would rather specify requirements
for a file a upload: type, size, mismatches between the file name and its
contents and so on. This module cannot hope to provide such open ended
functionality but it can provide extension mechanisms.

This module works with L<CGI> (the default), L<CGI::Minimal> and 
L<CGI::Simple>. In principle it ought to work with all equivalent modules
however each module has a slightly different interface when it comes
to file uploads and so requires slightly different test code.

INTERFACE

Several of the methods below take named parameters. For convenience we define those parameters here:

cgi

This option defines the CGI module. It should be a scalar consisting only of alphanumeric characters and ::. It defaults to 'CGI'.

name

This is the name of form parameter. It must be a scalar.

value

This is the value of the form parameter. It should either be a scalar or an array reference of scalars.

file

Where a form parameter represents a file, this is the name of that file.

type

The MIME type of the content. This defaults to 'text/plain'.

ua

The HTTP_USER_AGENT environment variable. This defaults to 'Test::CGI::Multipart'.

new

An instance of this class might best be thought of as a "CGI object factory". The constructor takes no parameters.

create_cgi

This returns a CGI object created according to the specification encapsulated in the object. The exact mechanics are as follows:

The parameters are packaged up in MIME format.
The environment variables are set.
A pipe is created. The far end of the pipe is attached to our standard input and the MIME content is pushed through the pipe.
The appropriate CGI class is required.
Uploads are enabled if the CGI class is CGI::Simple.
The CGI object is created and returned.

As far as I can see this simulates what happens when a CGI script processes a multi-part POST form. One can specify a different CGI class using the cgi named parameter. One can set the HTTP_USER_AGENT environment variable with the ua parameter.

set_param

This can be used to set a single form parameter. It takes two named arguments name and value. Note that this method overrides any previous settings including file uploads.

get_param

This retrieves a single form parameter. It takes a single named parameter: name. The data returned will be a list either of scalar values or (in the case of a file upload) of HASHREFs. The HASHREFs would have the following fields: file, value and type representing the parameter name, the file name, the content and the MIME type respectively.

get_names

This returns a list of stashed parameter names.

upload_file

In the absence of any defined callbacks, this method takes three mandatory named parameters: name, file and value and one optional parameter type. If there are any callbacks then the parameters are passed through each of the callbacks and must meet the standard parameter requirements by the time all the callbacks have been called.

Unlike the set_param method this will not override previous settings for this parameter but will add. However setting a normal parameter and then an upload on the same name will throw an error.

register_callback

Callbacks are used by the upload_file method, to allow a file to be specified by properties rather than strict content. This method takes a single named parameter called callback, which adds that callback to an internal array of callbacks. The idea being that the upload_file method can take any arguments you like so long as after all the callbacks have been applied, the parameters consist of name, file, value and possibly type. A callback should take and return a single hash reference.

DIAGNOSTICS

unexpected data structure

During the construction of the MIME data, the internal data structure turned out to have unexpected features. Since we control that data structure that should not happen.

mismatch: is %s a file upload or not

The parameter was being used for both for file upload and normal parameters.

CONFIGURATION AND ENVIRONMENT

Test::CGI::Multipart requires no configuration files or environment variables.

However it should be noted that the module will overwrite the following environment variables:

REQUEST_METHOD
CONTENT_LENGTH
CONTENT_TYPE
HTTP_USER_AGENT

INCOMPATIBILITIES

I would like to get this working with CGI::Lite::Request and Apache::Request if that makes sense. So far I have not managed that.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests to bug-test-cgi-multipart@rt.cpan.org, or through the web interface at http://rt.cpan.org.

This module depends upon MIME::Tools. Unfortunately that module does not handle newlines quite correctly. That seems to work fine for email but does not work with CGI. I have looked at MIME::Fast and MIME::Lite but MIME::Tools combined with a hack seems the best that can be done at the moment. Sooner or later someone is going to hit the limitations of that hack.

AUTHOR

Nicholas Bamber <nicholas@periapt.co.uk>

LICENCE AND COPYRIGHT

Copyright (c) 2010, Nicholas Bamber <nicholas@periapt.co.uk>. All rights reserved.

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

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