NAME
   HTTP::Request::Form - Construct HTTP::Request objects for form
   processing

SYNOPSIS
   use the following as a tool to query Altavista for "perl" from
   the commandline:

     use URI::URL;
     use LWP::UserAgent;
     use HTTP::Request;
     use HTTP::Request::Common;
     use HTTP::Request::Form;
     use HTML::TreeBuilder 3.0;

     my $ua = LWP::UserAgent->new;
     my $url = url 'http://www.altavista.digital.com/';
     my $res = $ua->request(GET $url);
     my $tree = HTML::TreeBuilder->new;
     $tree->parse($res->content);
     $tree->eof();

     my @forms = $tree->find_by_tag_name('FORM');
     die "What, no forms in $url?" unless @forms;
     my $f = HTTP::Request::Form->new($forms[0], $url);
     $f->field("q", "perl");
     my $response = $ua->request($f->press("search"));
     print $response->content if $response->is_success;

DESCRIPTION
   This is an extension of the HTTP::Request suite. It allows easy
   processing of forms in a user agent by filling out fields,
   querying fields, selections and buttons and pressing buttons. It
   uses HTML::TreeBuilder generated parse trees of documents
   (especially the forms parts extracted with extract_links) and
   generates it's own internal representation of forms from which
   it then generates the request objects to process the form
   application.

CLASS METHODS
   new($form [, $base [, $debug]])
       The `new-method' constructs a new form processor. It get's
       an HTML::Element object that contains a FORM element or
       ISINDEX element as the single parameter. If an base-url is
       given as an additional parameter, this is used to make the
       form-url absolute in regard to the given URL.

       If debugging is true, the following functions will be a bit
       "talky" on stdio.

   new_many($tree_part [, $base [, $debug]])
       The `new_many' method returns a list of newly constructed
       form processors. It's just like the `new' method except that
       it can apply to any part of an HTML::Element tree, including
       the root; it constructs a new form processor for each FORM
       element at or under `$tree_part'.

       Note that the return list might have zero, one or many new
       objects in it, depending on how many FORM (or ISINDEX)
       elements were found.

       Form elements (like INPUT, etc.) found outside of FORM
       elements are counted as being part of the preceding FORM
       element. (And if there is no preceding FORM element, they
       are ignored.) This feature is useful with the odd parse
       trees that can result from basd HTML in or around FORM
       elements. If you need to override that feature, then instead
       call:

         map HTTP::Request::Form->new($_), $tree->find_by_tag_name('FORM');

INSTANCE METHODS
   base()
       This returns the parameter $base to the "new" constructor.

   link()
       This returns the action attribute of the original form
       structure. This value is cached within the form processor,
       so you can safely delete the form structure after you
       created the form processor.

   method()
       This returns the method attribute of the original form
       structure. This value is cached within the form processor,
       so you can safely delete the form structure as soon as you
       created the form processor.

   isindex()
       This returns true if this came from an original form
       structure that was actually an ISINDEX element. In that
       case, the form will hagve only one field, an input/text
       field named "keywords".

   name()
       This returns the name attribute of the original form
       structure. This value is cached within the form processor,
       so you can safely delete the form structure after you
       created the form processor.

   fields()
       This method delivers a list of fieldnames that are of "open"
       type. This excludes the "hidden" and "submit" elements,
       because they are already filled with a value (and as such
       declared as "closed") or as in the case of "submit" are
       buttons, of which only one must be used.

   allfields()
       This delivers a list of all fieldnames in the order as they
       occured in the form-source excluding the submit fields.

   field($name [, $value])
       This method retrieves or sets a field-value. The field is
       identified by its name. You have to be sure that you only
       put a allowed value into the field.

   field_type($name)
       This method gives you the type of the named field, so that
       you can distinguish on this type. (this is the only way to
       distinguish selections and radio buttons).

   is_selection($name)
       This tests if a field is a selection or an input. Radio-
       Buttons are used in the same way as standard selection
       fields, so is_selection returns a true value for radio
       buttons, too! (Of course, only one value is submitted for a
       radio button)

   field_selection($name)
       This delivers the array of the options of a selection. The
       element that is marked with selected in the source is given
       as the default value. This works in the same way for radio
       buttons, as they are just handled as a special case of
       selections!

   is_checkbox($name)
       This tells you if a field is a checkbox. If it is, there are
       several support methods to make use of the special features
       of checkboxes, for example the fact that it is only sent if
       it is checked.

   checkboxes()
       This method delivers a list of all checkbox fields much in
       the same way as the buttons method.

   checkbox_check($name)
   checkbox_uncheck($name)
   checkbox_toggle($name)
       These methods set, unset or toggle the checkbox checked
       state. Checkbox values are only added to the result if they
       are checked.

   checkbox_ischecked($name)
       This methods tells you wether a checkbox is checked or not.
       This is important if you want to analyze the state of fields
       directly after the parse.

   buttons()
       This delivers a list of all defined and named buttons of a
       form.

   button($button [, $value])
       This gets or sets the value of a button. Normally only
       getting a button value is needed. The value of a button is a
       reference to an array of values (because a button can exist
       multiple times).

   button_type($button)
       This gives you the type of a button (submit/reset/image).
       The result is an array of type names, as a button with one
       name can exist multiple times.

   button_exists($button)
       This gives true if the named button exists, false (undef)
       otherwise.

   referer([$value])
       This returns or sets the referer header for an request. This
       is useful if a CGI needs a set referer for authentication.

   press([$name [, $coord ] [, $number]])
       This method creates a HTTP::Request object (via
       HTTP::Request::Common) that sends the formdata to the server
       with the requested method. If you give a button-name, that
       button is used. If you give no button name, it assumes a
       button without a name and just leaves out this last
       parameter. If the number of the button is given, that button
       value is delivered. If the number is not given, 0 (the first
       button of this name) is assumed.

       The "coord" parameter comes in handy if you have an image
       button. If this is the case, the button press will simulate
       a press at coordinates [2,2] unless you provide an anonymous
       array with different coordinates.

   dump()
       This method dumps the form-data on stdio for debugging
       purpose.

SEE ALSO
   the HTTP::Request manpage, the HTTP::Request::Common manpage,
   the LWP::UserAgent manpage, the HTML::Element manpage, the
   URI::URL manpage

INSTALLATION
     perl Makefile.PL
     make install

   or see the perlmodinstall manpage

REQUIRES
     Perl version 5.004 or later

     HTTP::Request::Common
     HTML::TreeBuilder
     LWP::UserAgent

VERSION
   HTTP::Request::Form version 0.9, February 8th, 2001

RESTRICTIONS
   Only a subset of all possible form elements are currently
   supported. The list of supported tags as of this version
   includes:

     INPUT/CHECKBOX
     INPUT/HIDDEN
     INPUT/IMAGE
     INPUT/RADIO
     INPUT/RESET
     INPUT/SUBMIT
     INPUT/FILE
     INPUT/* (are all handled as simple text entry)
     OPTION
     SELECT
     TEXTAREA
     ISINDEX

BUGS
   There is currently no support for multiple selections (you can
   do them yourself by setting a selection to a comma-delimited
   list of values).

   Multiple fields are not properly handled, only the last value is
   available. Exception are buttons, they are handled in the right
   way.

   If there are several fields with the same name, you can only set
   the value of the first of this fields (this is especially
   problematic with checkboxes). This does work with buttons that
   have the same name, though (you can press each instance
   identified by number).

   Error-Checking is currently very limited (not to say
   nonexistant).

   Support for HTML 4.0 optgroup tags is missing (as is with
   allmost all current browsers, so that is not a great loss).

   The button tag (HTML 4.0) is just handled as an alias for the
   input tag - this is of course incorrect, but sufficient for
   support of the usual button types.

COPYRIGHT
   Copyright 1998, 1999, 2000 Georg Bauer
   <[email protected]>

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

MAJOR CONTRIBUTORS
   Sean M. Burke (ISINDEX, new_many)