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

VERSION
    This document describes Test::CGI::Multipart version 0.0.2

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 web forms including file uploads.

    However we also recognise 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 CGI (the default), CGI::Minimal and 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.
    Global variables are reset for CGI and CGI::Minimal.
    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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