HTML::Form(3) User Contributed Perl Documentation HTML::Form(3)

NAME
       HTML::Form - Class that represents an HTML form element

SYNOPSIS
        use HTML::Form;
        $form = HTML::Form->parse($html, $baseuri);
        $form->value(query => "Perl");

        use LWP::UserAgent;
        $ua = LWP::UserAgent->new;
        $response = $ua->request($form->click);

DESCRIPTION
       Objects of the "HTML::Form" class represents a single HTML "
 ...
       " instance.  A form consists of a sequence of inputs that
       usually have names, and which can take on various values.  The state of
       a form can be tweaked and it can then be asked to provide
       "HTTP::Request" objects that can be passed to the request() method of
       "LWP::UserAgent".

       The following methods are available:

       @forms = HTML::Form->parse( $response )
       @forms = HTML::Form->parse( $htmldocument, $base )
       @forms = HTML::Form->parse( $htmldocument, %opt )
           The parse() class method will parse an HTML document and build up
           "HTML::Form" objects for each 
 element found.  If called in
           scalar context only returns the first .  Returns an empty
           list if there are no forms to be found.

           The $base is the URI used to retrieve the $htmldocument.  It is
           needed to resolve relative action URIs.  If the document was
           retrieved with LWP then this this parameter is obtained from the
           $response->base() method, as shown by the following example:

               my $ua = LWP::UserAgent->new;
               my $response = $ua->get("http://www.example.com/form.html");
               my @forms = HTML::Form->parse($response->decodedcontent,
                                             $response->base);

           The parse() method can parse from an "HTTP::Response" object
           directly, so the example above can be more conveniently written as:

               my $ua = LWP::UserAgent->new;
               my $response = $ua->get("http://www.example.com/form.html");
               my @forms = HTML::Form->parse($response);

           Note that any object that implements a decodedcontent() and base()
           method with similar behaviour as "HTTP::Response" will do.

           Finally options might be passed in to control how the parse method
           behaves.  The following options are currently recognized:

           "base"
               Another way to provide the base URI.

           "verbose"
               Print messages to STDERR about any bad HTML form constructs
               found.

       $method = $form->method
       $form->method( $newmethod )
           This method is gets/sets the method name used for the
           "HTTP::Request" generated.  It is a string like "GET" or "POST".

       $action = $form->action
       $form->action( $newaction )
           This method gets/sets the URI which we want to apply the request
           method to.

       $enctype = $form->enctype
       $form->enctype( $newenctype )
           This method gets/sets the encoding type for the form data.  It is a
           string like "application/x-www-form-urlencoded" or
           "multipart/form-data".

       $value = $form->attr( $name )
       $form->attr( $name, $newvalue )
           This method give access to the original HTML attributes of the
            tag.  The $name should always be passed in lower case.

           Example:

              @f = HTML::Form->parse( $html, $foo );
              @f = grep $->attr("id") eq "foo", @f;
              die "No form named 'foo' found" unless @f;
              $foo = shift @f;

       @inputs = $form->inputs
           This method returns the list of inputs in the form.  If called in
           scalar context it returns the number of inputs contained in the
           form.  See "INPUTS" for what methods are available for the input
           objects returned.

       $input = $form->findinput( $name )
       $input = $form->findinput( $name, $type )
       $input = $form->findinput( $name, $type, $index )
           This method is used to locate specific inputs within the form.  All
           inputs that match the arguments given are returned.  In scalar
           context only the first is returned, or "undef" if none match.

           If $name is specified, then the input must have the indicated name.

           If $type is specified, then the input must have the specified type.
           The following type names are used: "text", "password", "hidden",
           "textarea", "file", "image", "submit", "radio", "checkbox" and
           "option".

           The $index is the sequence number of the input matched where 1 is
           the first.  If combined with $name and/or $type then it select the
           nth input with the given name and/or type.

       $value = $form->value( $name )
       $form->value( $name, $newvalue )
           The value() method can be used to get/set the value of some input.
           If no input has the indicated name, then this method will croak.

           If multiple inputs have the same name, only the first one will be
           affected.

           The call:

               $form->value('foo')

           is a short-hand for:

               $form->findinput('foo')->value;

       @names = $form->param
       @values = $form->param( $name )
       $form->param( $name, $value, ... )
       $form->param( $name, \@values )
           Alternative interface to examining and setting the values of the
           form.

           If called without arguments then it returns the names of all the
           inputs in the form.  The names will not repeat even if multiple
           inputs have the same name.  In scalar context the number of
           different names is returned.

           If called with a single argument then it returns the value or
           values of inputs with the given name.  If called in scalar context
           only the first value is returned.  If no input exists with the
           given name, then "undef" is returned.

           If called with 2 or more arguments then it will set values of the
           named inputs.  This form will croak if no inputs have the given
           name or if any of the values provided does not fit.  Values can
           also be provided as a reference to an array.  This form will allow
           unsetting all values with the given name as well.

           This interface resembles that of the param() function of the CGI
           module.

       $form->tryothers( \&callback )
           This method will iterate over all permutations of unvisited
           enumerated values (, , ) and invoke the
           callback for each.  The callback is passed the $form as argument.
           The return value from the callback is ignored and the tryothers()
           method itself does not return anything.

       $request = $form->makerequest
           Will return an "HTTP::Request" object that reflects the current
           setting of the form.  You might want to use the click() method
           instead.

       $request = $form->click
       $request = $form->click( $name )
       $request = $form->click( $x, $y )
       $request = $form->click( $name, $x, $y )
           Will "click" on the first clickable input (which will be of type
           "submit" or "image").  The result of clicking is an "HTTP::Request"
           object that can then be passed to "LWP::UserAgent" if you want to
           obtain the server response.

           If a $name is specified, we will click on the first clickable input
           with the given name, and the method will croak if no clickable
           input with the given name is found.  If $name is not specified,
           then it is ok if the form contains no clickable inputs.  In this
           case the click() method returns the same request as the
           makerequest() method would do.

           If there are multiple clickable inputs with the same name, then
           there is no way to get the click() method of the "HTML::Form" to
           click on any but the first.  If you need this you would have to
           locate the input with findinput() and invoke the click() method on
           the given input yourself.

           A click coordinate pair can also be provided, but this only makes a
           difference if you clicked on an image.  The default coordinate is
           (1,1).  The upper-left corner of the image is (0,0), but some badly
           coded CGI scripts are known to not recognize this.  Therefore (1,1)
           was selected as a safer default.

       @kw = $form->form
           Returns the current setting as a sequence of key/value pairs.  Note
           that keys might be repeated, which means that some values might be
           lost if the return values are assigned to a hash.

           In scalar context this method returns the number of key/value pairs
           generated.

       $form->dump
           Returns a textual representation of current state of the form.
           Mainly useful for debugging.  If called in void context, then the
           dump is printed on STDERR.

IINNPPUUTTSS
       An "HTML::Form" objects contains a sequence of inputs.  References to
       the inputs can be obtained with the $form->inputs or $form->findinput
       methods.

       Note that there is not a one-to-one correspondence between input
       objects and  elements in the HTML document.  An input object
       basically represents a name/value pair, so when multiple HTML elements
       contribute to the same name/value pair in the submitted form they are
       combined.

       The input elements that are mapped one-to-one are "text", "textarea",
       "password", "hidden", "file", "image", "submit" and "checkbox".  For
       the "radio" and "option" inputs the story is not as simple: All  elements with the same name will contribute to the same
       input radio object.  The number of radio input objects will be the same
       as the number of distinct names used for the 
       elements.  For a  element without the "multiple" attribute
       there will be one input object of type of "option".  For a  element there will be one input object for each contained
        element.  Each one of these option objects will have the same
       name.

       The following methods are available for the input objects:

       $input->type
           Returns the type of this input.  The type is one of the following
           strings: "text", "password", "hidden", "textarea", "file", "image",
           "submit", "radio", "checkbox" or "option".

       $name = $input->name
       $input->name( $newname )
           This method can be used to get/set the current name of the input.

       $value = $input->value
       $input->value( $newvalue )
           This method can be used to get/set the current value of an input.

           If the input only can take an enumerated list of values, then it is
           an error to try to set it to something else and the method will
           croak if you try.

           You will also be able to set the value of read-only inputs, but a
           warning will be generated if running under "perl -w".

       $input->possiblevalues
           Returns a list of all values that an input can take.  For inputs
           that do not have discrete values, this returns an empty list.

       $input->otherpossiblevalues
           Returns a list of all values not tried yet.

       $input->valuenames
           For some inputs the values can have names that are different from
           the values themselves.  The number of names returned by this method
           will match the number of values reported by
           $input->possiblevalues.

           When setting values using the value() method it is also possible to
           use the value names in place of the value itself.

       $bool = $input->readonly
       $input->readonly( $bool )
           This method is used to get/set the value of the readonly attribute.
           You are allowed to modify the value of readonly inputs, but setting
           the value will generate some noise when warnings are enabled.
           Hidden fields always start out readonly.

       $bool = $input->disabled
       $input->disabled( $bool )
           This method is used to get/set the value of the disabled attribute.
           Disabled inputs do not contribute any key/value pairs for the form
           value.

       $input->formnamevalue
           Returns a (possible empty) list of key/value pairs that should be
           incorporated in the form value from this input.

       $input->check
           Some input types represent toggles that can be turned on/off.  This
           includes "checkbox" and "option" inputs.  Calling this method turns
           this input on without having to know the value name.  If the input
           is already on, then nothing happens.

           This has the same effect as:

               $input->value($input->possiblevalues[1]);

           The input can be turned off with:

               $input->value(undef);

       $input->click($form, $x, $y)
           Some input types (currently "submit" buttons and "images") can be
           clicked to submit the form.  The click() method returns the
           corresponding "HTTP::Request" object.

       If the input is of type "file", then it has these additional methods:

       $input->file
           This is just an alias for the value() method.  It sets the filename
           to read data from.

       $filename = $input->filename
       $input->filename( $newfilename )
           This get/sets the filename reported to the server during file
           upload.  This attribute defaults to the value reported by the
           file() method.

       $content = $input->content
       $input->content( $newcontent )
           This get/sets the file content provided to the server during file
           upload.  This method can be used if you do not want the content to
           be read from an actual file.

       @headers = $input->headers
       input->headers($key => $value, .... )
           This get/set additional header fields describing the file uploaded.
           This can for instance be used to set the "Content-Type" reported
           for the file.

SEE ALSO
       LWP, LWP::UserAgent, HTML::Parser

COPYRIGHT
       Copyright 1998-2005 Gisle Aas.

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



perl v5.8.8                       2005-12-07                     HTML::Form(3)