package HTML::AsSubs;

=head1 NAME

HTML::AsSubs - functions that construct a HTML syntax tree

=head1 SYNOPSIS

 use HTML::AsSubs;
 $h = body(
	   h1("This is the heading"),
	   p("This is the first paragraph which contains a ",
	     a({href=>'link.html'}, "link"),
	     " and an ",
	     img({src=>'img.gif', alt=>'image'}),
	     "."
	    ),
	  );
 print $h->as_HTML;

=head1 DESCRIPTION

This module exports functions that can be used to construct various
HTML elements. The functions are named after the tags of the
correponding HTML element and are all written in lower case. If the
first argument is a I<hash> then it will be used to initialize the
attributes of this element. The remaining arguments are regarded as
content.

=head1 ACKNOWLEDGEMENT

This module was inspired by the following message:

 Date: Tue, 4 Oct 1994 16:11:30 +0100
 Subject: Wow! I have a large lightbulb above my head!

 Take a moment to consider these lines:

 %OVERLOAD=( '""' => sub { join("", @{$_[0]}) } );

 sub html { my($type)=shift; bless ["<$type>", @_, "</$type>"]; }

 :-)  I *love* Perl 5!  Thankyou Larry and Ilya.

 Regards,
 Tim Bunce.

 p.s. If you didn't get it, think about recursive data types: html(html())
 p.p.s. I'll turn this into a much more practical example in a day or two.
 p.p.p.s. It's a pity that overloads are not inherited. Is this a bug?

=head1 BUGS

The exported link() function overrides the builtin link() function.
The exported tr() function must be called using &tr(...) syntax
because it clashes with the builtin tr/../../ operator.


=head1 SEE ALSO

L<HTML::Element>

=cut

require HTML::Element;
require Exporter;
@ISA = qw(Exporter);

@TAGS = qw(html
	   head title base link meta isindex nextid
	   body h1 h2 h3 h4 h5 h6 p pre address blockquote
	   a img br hr
	   ol ul dir menu li
	   dl dt dd
	   cite code em kbd samp strong var
	   b i u tt
	   table tr td th caption
	   form input select option textarea
	  );

for (@TAGS) {
    push(@code, "sub $_ { _elem('$_', \@_); }\n");
    push(@EXPORT, $_);
}
eval join('', @code);
if ($@) {
    die $@;
}

sub _elem
{
    my $tag = shift;
    my $attributes;
    if (@_ and defined $_[0] and ref($_[0]) eq "HASH") {
	$attributes = shift;
    }
    my $elem = new HTML::Element $tag, %$attributes;
    $elem->push_content(@_);
    $elem;
}

1;