HTML::FillInForm - Populates HTML Forms with data.

  $output = HTML::FillInForm->fill( \$html,   $q );
  $output = HTML::FillInForm->fill( \@html,   [$q1,$q2] );
  $output = HTML::FillInForm->fill( \*HTML,   \%data );
  $output = HTML::FillInForm->fill( 't.html', [\%data1,%data2] );

  $output = HTML::FillInForm->fill(\$html, $q, target => 'form1');

  <FORM name="form1"> ... </FORM>

  fill_password => 0

    ignore_fields => ['prev','next']

    disable_fields => [ 'uid', 'gid' ]

  # this will leave the form element foo untouched
  HTML::FillInForm->fill(\$html, { foo => undef });

  # this will set clear the form element foo
  HTML::FillInForm->fill(\$html, { foo => "" });

  $fif = HTML::FillInForm->new;
  $fif->fill(...);

    arrayref  => @html
    scalarref => $html
    file      => \*HTML 
    file      => 't.html'

    fobject   => $data_obj  # with param() method
    fdat      => \%data

    fill_file(\*HTML,...);
    fill_file('t.html',...);
    fill_arrayref(\@html,...);
    fill_scalarref(\$html,...);

  PerlSetVar FormFill 1
  $Response->{FormFill} = 1

  Tatsuhiko Miyagawa            Joseph Yanni
  Boris Zentner                 Philip Mak
  Dave Rolsky                   Jost Krieger
  Patrick Michael Kane          Gabriel Burka
  Ade Olonoh                    Bill Moseley
  Tom Lancaster                 James Tolley
  Martin H Sluka                Dan Kubb
  Mark Stosberg                 Alexander Hartmaier
  Jonathan Swartz               Paul Miller
  Trevor Schellhorn             Anthony Ettinger
  Jim Miner                     Simon P. Ditner
  Paul Lindner                  Michael Peters
  Maurice Aubrey                Trevor Schellhorn
  Andrew Creer                

package HTML::FillInForm;

use integer; # no floating point math so far!
use strict; # and no funny business, either.

use Carp; # generate better errors with more context

# required for attr_encoded
use HTML::Parser 3.26;

# required for UNIVERSAL->can
require 5.005;

use vars qw($VERSION @ISA);
$VERSION = '2.00';

@ISA = qw(HTML::Parser);

sub new {
  my ($class) = @_;
  my $self = bless {}, $class;
  $self->init;
  # tell HTML::Parser not to decode attributes
  $self->attr_encoded(1);
  return $self;
}

# a few shortcuts to fill()
sub fill_file      { my $self = shift; return $self->fill('file'     ,@_); }
sub fill_arrayref  { my $self = shift; return $self->fill('arrayref' ,@_); }
sub fill_scalarref { my $self = shift; return $self->fill('scalarref',@_); }

# track the keys we support. Useful for file-name detection.
sub _known_keys {
    return {
        scalarref      =>  1,
        arrayref       =>  1,
        fdat           =>  1,
        fobject        =>  1,
        file           =>  1,
        target         =>  1,
        fill_password  =>  1,
        ignore_fields  =>  1,
        disable_fields =>  1,
    }
}

sub fill {
   my $self = shift;

  # If we are called as a class method, go ahead and call new().
  $self = $self->new if (not ref $self);

  my %option;

  # If the first arg is a scalarref, translate that to scalarref => $first_arg
  if (ref $_[0] eq 'SCALAR') {
      $option{scalarref} = shift;
  }
  elsif (ref $_[0] eq 'ARRAY') {
      $option{arrayref} = shift;
  }
  elsif (ref $_[0] eq 'GLOB') {
      $option{file} = shift;
  }
  elsif (ref $_[0]) {
    croak "data source is not a reference type we understand";
  }
  # Last chance, if the first arg isn't one of the known keys, we 
  # assume it is a file name.
  elsif (not _known_keys()->{$_[0]} )  {
    $option{file} =  shift;
  }
  else {
      # Should be a known key. Nothing to do.
  }


  # Now, check to see if the next arg is also a reference. 
  my $data;
  if (ref $_[0]) {
      $data = shift;
      $data = [$data] unless ref $data eq 'ARRAY';

      for my $source (@$data) {
          if (ref $source eq 'HASH') {
              push @{ $option{fdat} }, $source;
          }
          elsif (ref $source) {
              if ($source->can('param')) {
                  push @{ $option{fobject} }, $source;
              }
              else {
                  croak "data source $source does not supply a param method";
              }
          }
          elsif (defined $source) {
              croak "data source $source is not a hash or object reference";
          }
      }

  }

 
  # load in the rest of the options
  %option = (%option, @_);


  # As suggested in the docs, merge multiple fdats into one. 
  if (ref $option{fdat} eq 'ARRAY') {
      my %merged;
      for my $hash (@{ $option{fdat} }) {
          for my $key (keys %$hash) {
              $merged{$key} = $hash->{$key};
          }
      }
      $option{'fdat'} = \%merged;
  }


  my %ignore_fields;
  %ignore_fields = map { $_ => 1 } ( ref $option{'ignore_fields'} eq 'ARRAY' )
    ? @{ $option{ignore_fields} } : $option{ignore_fields} if exists( $option{ignore_fields} );
  $self->{ignore_fields} = \%ignore_fields;

  my %disable_fields;
  %disable_fields = map { $_ => 1 } ( ref $option{'disable_fields'} eq 'ARRAY' )
    ? @{ $option{disable_fields} } : $option{disable_fields} if exists( $option{disable_fields} );
  $self->{disable_fields} = \%disable_fields;

  if (my $fdat = $option{fdat}){
    # Copy the structure to prevent side-effects.
    my %copy;
    keys %$fdat; # reset fdat if each or Dumper was called on fdat
    while(my($key, $val) = each %$fdat) {
      next if exists $ignore_fields{$key};
      $copy{ $key } = ref $val eq 'ARRAY' ? [ @$val ] : $val;
    }
    $self->{fdat} = \%copy;
  }

  # We want the reference to these objects to go out of scope at the
  # end of the method.
  local $self->{objects} = [];
  if(my $objects = $option{fobject}){
    unless(ref($objects) eq 'ARRAY'){
      $objects = [ $objects ];
    }
    for my $object (@$objects){
      # make sure objects in 'param_object' parameter support param()
      defined($object->can('param')) or
	croak("HTML::FillInForm->fill called with fobject option, containing object of type " . ref($object) . " which lacks a param() method!");
    }

    $self->{objects} = $objects;
  }
  if (my $target = $option{target}){
    $self->{'target'} = $target;
  }

  if (defined($option{fill_password})){
    $self->{fill_password} = $option{fill_password};
  } else {
    $self->{fill_password} = 1;
  }

  # make sure method has data to fill in HTML form with!
  unless(exists $self->{fdat} || $self->{objects}){
    croak("HTML::FillInForm->fillInForm() called without 'fobject' or 'fdat' parameter set");
  }

  local $self->{object_param_cache};

  if(my $file = $option{file}){
    $self->parse_file($file);
  } elsif (my $scalarref = $option{scalarref}){
    $self->parse($$scalarref);
  } elsif (my $arrayref = $option{arrayref}){
    for (@$arrayref){
      $self->parse($_);
    }
  }

  $self->eof;
  return delete $self->{output};
}

# handles opening HTML tags such as <input ...>
sub start {
  my ($self, $tagname, $attr, $attrseq, $origtext) = @_;

  # set the current form
  if ($tagname eq 'form') {
    $self->{object_param_cache} = {};
    if (exists $attr->{'name'} || exists $attr->{'id'}) {
      $self->{'current_form'} = $attr->{'name'} || $attr->{'id'};
    } else {
      # in case of previous one without </FORM>
      delete $self->{'current_form'};
    }
  }

  # This form is not my target.
  if (exists $self->{'target'} &&
      (! exists $self->{'current_form'} ||
       $self->{'current_form'} ne $self->{'target'})) {
    $self->{'output'} .= $origtext;
    return;
  }
  
  # HTML::Parser converts tagname to lowercase, so we don't need /i
  if ($self->{option_no_value}) {
    $self->{output} .= '>';
    delete $self->{option_no_value};
  }

  # Check if we need to disable  this field
  $attr->{disable} = 1
    if exists $attr->{'name'} and
    exists $self->{disable_fields}{ $attr->{'name'} } and
    $self->{disable_fields}{ $attr->{'name'} } and
    not ( exists $attr->{disable} and $attr->{disable} );
  if ($tagname eq 'input'){
    my $value = exists $attr->{'name'} ? $self->_get_param($attr->{'name'}) : undef;
    # force hidden fields to have a value
    $value = '' if exists($attr->{'type'}) && $attr->{'type'} eq 'hidden' && ! exists $attr->{'value'} && ! defined $value;
    if (defined($value)){
      $value = $self->escapeHTMLStringOrList($value);
      # check for input type, noting that default type is text
      if (!exists $attr->{'type'} ||
	  $attr->{'type'} =~ /^(text|textfield|hidden|)$/i){
	if ( ref($value) eq 'ARRAY' ) {
	  $value = shift @$value;
	  $value = '' unless defined $value;
        }
	$attr->{'value'} = $value;
      } elsif (lc $attr->{'type'} eq 'password' && $self->{fill_password}) {
	if ( ref($value) eq 'ARRAY' ) {
	  $value = shift @$value;
	  $value = '' unless defined $value;
        }
	$attr->{'value'} = $value;
      } elsif (lc $attr->{'type'} eq 'radio'){
	if ( ref($value) eq 'ARRAY' ) {
	  $value = $value->[0];
	  $value = '' unless defined $value;
        }
	# value for radio boxes default to 'on', works with netscape
	$attr->{'value'} = 'on' unless exists $attr->{'value'};
	if ($attr->{'value'} eq $value){
	  $attr->{'checked'} = 'checked';
	} else {
	  delete $attr->{'checked'};
	}
      } elsif (lc $attr->{'type'} eq 'checkbox'){
	# value for checkboxes default to 'on', works with netscape
	$attr->{'value'} = 'on' unless exists $attr->{'value'};

	delete $attr->{'checked'}; # Everything is unchecked to start
        $value = [ $value ] unless ref($value) eq 'ARRAY';
	foreach my $v ( @$value ) {
	  if ( $attr->{'value'} eq $v ) {
	    $attr->{'checked'} = 'checked';
	  }
	}
#      } else {
#	warn(qq(Input field of unknown type "$attr->{type}": $origtext));
      }
    }
    $self->{output} .= "<$tagname";
    while (my ($key, $value) = each %$attr) {
      next if $key eq '/';
      $self->{output} .= sprintf qq( %s="%s"), $key, $value;
    }
    # extra space put here to work around Opera 6.01/6.02 bug
    $self->{output} .= ' /' if $attr->{'/'};
    $self->{output} .= ">";
  } elsif ($tagname eq 'option'){
    my $value = $self->_get_param($self->{selectName});
    $value = [ $value ] unless ( ref($value) eq 'ARRAY' );

    if ( defined $value->[0] ){
      $value = $self->escapeHTMLStringOrList($value);
      delete $attr->{selected} if exists $attr->{selected};
      
      if(defined($attr->{'value'})){
        # option tag has value attr - <OPTION VALUE="foo">bar</OPTION>
        
        if ($self->{selectMultiple}){
          # check if the option tag belongs to a multiple option select
	  foreach my $v ( grep { defined } @$value ) {
	    if ( $attr->{'value'} eq $v ){
	      $attr->{selected} = 'selected';
	    }
          }
        } else {
          # if not every value of a fdat ARRAY belongs to a different select tag
          if (not $self->{selectSelected}){
	    if ( $attr->{'value'} eq $value->[0]){
	      shift @$value if ref($value) eq 'ARRAY';
	      $attr->{selected} = 'selected';
              $self->{selectSelected} = 1; # remeber that an option tag is selected for this select tag
	    }
          }
        }
      } else {
        # option tag has no value attr - <OPTION>bar</OPTION>
	# save for processing under text handler
	$self->{option_no_value} = $value;
      }
    }
    $self->{output} .= "<$tagname";
    while (my ($key, $value) = each %$attr) {
      $self->{output} .= sprintf qq( %s="%s"), $key, $value;
    }
    unless ($self->{option_no_value}){
      # we can close option tag here
      $self->{output} .= ">";
    }
  } elsif ($tagname eq 'textarea'){
    if ($attr->{'name'} and defined (my $value = $self->_get_param($attr->{'name'}))){
      $value = $self->escapeHTMLStringOrList($value);
      $value = (shift @$value || '') if ref($value) eq 'ARRAY';
      # <textarea> foobar </textarea> -> <textarea> $value </textarea>
      # we need to set outputText to 'no' so that 'foobar' won't be printed
      $self->{outputText} = 'no';
      $self->{output} .= $origtext . $value;
    } else {
      $self->{output} .= $origtext;
    }
  } elsif ($tagname eq 'select'){
    $self->{selectName} = $attr->{'name'};
    if (defined $attr->{'multiple'}){
      $self->{selectMultiple} = 1; # helper var to remember if the select tag has the multiple attr set or not
    } else {
      $self->{selectMultiple} = 0;
      $self->{selectSelected} = 0; # helper var to remember if an option was already selected in the current select tag
    }
    $self->{output} .= $origtext;
  } else {
    $self->{output} .= $origtext;
  }
}

sub _get_param {
  my ($self, $param) = @_;

  return undef if $self->{ignore_fields}{$param};

  return $self->{fdat}{$param} if exists $self->{fdat}{$param};

  return $self->{object_param_cache}{$param} if exists $self->{object_param_cache}{$param};

  # traverse the list in reverse order for backwards compatibility
  # with the previous implementation.
  for my $o (reverse @{$self->{objects}}) {
    my @v = $o->param($param);

    next unless @v;

    return $self->{object_param_cache}{$param} = @v > 1 ? \@v : $v[0];
  }

  return undef;
}

# handles non-html text
sub text {
  my ($self, $origtext) = @_;
  # just output text, unless replaced value of <textarea> tag
  unless(exists $self->{outputText} && $self->{outputText} eq 'no'){
    if(exists $self->{option_no_value}){
      # dealing with option tag with no value - <OPTION>bar</OPTION>
      my $values = $self->{option_no_value};
      my $value = $origtext;
      $value =~ s/^\s+//;
      $value =~ s/\s+$//;
      foreach my $v ( @$values ) {
	if ( $value eq $v ) {
	  $self->{output} .= ' selected="selected"';
        }
      }
      # close <OPTION> tag
      $self->{output} .= ">$origtext";
      delete $self->{option_no_value};
    } else {
      $self->{output} .= $origtext;
    }
  }
}

# handles closing HTML tags such as </textarea>
sub end {
  my ($self, $tagname, $origtext) = @_;
  if ($self->{option_no_value}) {
    $self->{output} .= '>';
    delete $self->{option_no_value};
  }
  if($tagname eq 'select'){
    delete $self->{selectName};
  } elsif ($tagname eq 'textarea'){
    delete $self->{outputText};
  } elsif ($tagname eq 'form') {
    delete $self->{'current_form'};
  }
  $self->{output} .= $origtext;
}

sub escapeHTMLStringOrList {
  my ($self, $toencode) = @_;

  if (ref($toencode) eq 'ARRAY') {
    foreach my $elem (@$toencode) {
      $elem = $self->escapeHTML($elem);
    }
    return $toencode;
  } else {
    return $self->escapeHTML($toencode);
  }
}

sub escapeHTML {
  my ($self, $toencode) = @_;

  return undef unless defined($toencode);
  $toencode =~ s/&/&amp;/g;
  $toencode =~ s/\"/&quot;/g;
  $toencode =~ s/>/&gt;/g;
  $toencode =~ s/</&lt;/g;
  return $toencode;
}

sub comment {
    my ( $self, $text ) = @_;
    # if it begins with '[if ' and doesn't end with '<![endif]'
    # it's a "downlevel-revealed" conditional comment (stupid IE)
    # or
    # if it ends with '[endif]' then it's the end of a
    # "downlevel-revealed" conditional comment
    if(
        (
            ( index($text, '[if ') == 0 )
            &&
            ( $text !~ /<!\[endif\]$/ )
        )
        ||
        ( $text eq '[endif]' )
    ) {
        $self->{output} .= '<!' . $text . '>';
    } else {
        $self->{output} .= '<!--' . $text . '-->';
    }
}

sub process {
  my ( $self, $token0, $text ) = @_;
  $self->{output} .= $text;
}

sub declaration {
  my ( $self, $text ) = @_;
  $self->{output} .= '<!' . $text . '>';
}

1;

__END__