<!--
=head1 NAME

wwwtable_tag.wmk - easier HTML table generation using "freetable"

=head1 LOADING

  < use plugin="wwwtable_tag" />

=head1 HTML TAGS

  < wwwtable [...table options...] [freetableargs="string"] >
  ...randomly-addressed table...
  < /wwwtable>

=head1 DESCRIPTION

This WebMake Perl library provides the C<wwwtable> tag.  This is a useful way
to lay out HTML tables, using an more intuitive addressing system: instead of
listing all table entries, one by one, left to right and top to bottom, it
allows you to randomly, and flexibly, pick cells and define what goes into
them.

It's currently implemented using Tomasz Wegrzanowski's B<freetable> package.
This package must be installed for this tag to be used; it can be downloaded
from

	http://sourceforge.net/projects/freetable/

The remainder of this documentation is quoted (more or less verbatim)
from Tomasz' package.

Note that command-line options to B<freetable> can be provided using the
attribute C<freetableargs>.

=head1 FREETABLE DESCRIPTION

This is free replacement of B<wwwtable>.

HTML is great language, but have one horrible flaw :
tables. I spent many hours looking at HTML source I just written
and trying to guess which cell in source is which in browser.

If this also describes you, then read this manpage and your
pain will stop.

Program read HTML source from either I<stdin> or file (WebMake note: the HTML
source is read from between the I<E<lt>wwwtableE<gt>> tags in the WebMake
content). Then it searches for line starting table:

    <wwwtable [options]>

Then it analyzes table, put correct HTML table in this place and
continue searching for the next table.

=head1 TABLE SYNTAX

It is very easy:

    wwwtable :
    <wwwtable [wwwtable_options]>
    [preamble]
    [cell]
    [cell]
    ...
    </wwwtable>

wwwtable_options will be passed to I<E<lt>tableE<gt>> tags. There is
no magic inside preamble. It can be any HTML text. It will be simply
put in front of table.

cell is either normal_cell (I<E<lt>tdE<gt>> tag) or
header_cell (I<E<lt>thE<gt>> tag).
At least it was this way in freetable 1.x.
See the next section for alternative cell address syntax.

    normal_cell :
    (row,col) cell_options
    cell_content

    header_cell :
    ((row,col)) cell_options  
    cell_content

cell_options will be passed to cell tag. There is magic inside
I<colspan> and I<rowspan> keys are parsed to make correct table.

cell_content can be anything. It may contain text, tags, and
even nested wwwtables.

row and col are either numbers locating cells, expressions relative to previous
cell or regular expresions to match few of them. Unlike B<wwwtable>,
B<freetable> can use regular expresions for header cells. Also I<*> can be
used, and it mean I<.*> really.

Relative expressions are :

I<=> or empty means : the same as previous

I<+> or I<+X> means : one and X more than previous

I<-> or I<-X> means : one and X less than previous

If many definisions adress the same cell all options and contents are
concatenated in order of apperance.

If you want to use only regular expresions you must tell
program about the last cell :

    <wwwtable>
    (*,1)
    these are colums 1
    (1,*)
    these are rows 1
    (4,4)
    </wwwtable>

=head1 ALTERNATIVE CELL ADDRESS SYNTAX

It is inconvenient to specify cell address as regular expression.
So in B<freetable> 2.0 two new methods were introduced.
Both can be used to either normal or header cells.

Full bakward compatibility is preserved.
To preserve it, new syntax had to be introduced.
Unfortunatelly, you can't specify row
address using one method, and column address using another.
To come around this, both new methods are very liberal
and allow you to use I<=>, I<+>, I<->, I<+X> I<-X> and null
string with the same meaning as they have in old addressing
method.

Unlike regular expression method,
new methods will find out the last cell automatically.

=head2 EXPLICIT RANGES

    (rowrange;colrange) cell_options
    cell_content

Syntax for both rowrange and colrange is like: 1-2,4-7,9,12.
Duplicates will be eliminated. For purpose of relative addresses
last given number is used. So if you write

    (1-100,32;1)
    foo
    (+,)
    bar

Cell (33,1) will contain `foobar' and all others only `foo'.

=head2 ARBITRARY PERL CODE

    ({code for rows},{code for tables}) cell_options
    cell_content

You can use arbitrary Perl one-liner as long as it matches our
not very intelligent regular expressions and evaluates to list.
Unfortunatelly there isn't any regular expression for Perl code,
but as long as it doesn't contain I<},{> and I<})> it should work.
Example:

    <wwwtable>
    ({grep {$_%3 == 1} 1..100},{1..2,4})
    foo
    </wwwtable>

Will evaluate to 100 rows x 4 columns table with `foo' in
every 1st, 2nd and 4th column of every row with number equal 1 modulo 3.

If you want to use "arbitrary code" in one part of address and
explicit range in the other, change I<-> into I<..> in defenition of
range, and put in between I<{> and I<}>.

If you want to use "arbitrary code" in one part of address and
regular expression in the other, you have to write
I<{grep {/expression/} from..to}>.
Unfortunatelly, in this case you have to specify size of the table explicitely.

=head1 INCOMPATIBILITIES WITH WWWTABLE

If you was formerly user of B<wwwtable> and want to change your tool, you
should read this. Most of this is about regexps handling.
Notice also that B<wwwtable> couldnt do location tags substitution nor macroprocesing.

Option I<-w> has completely oposite meaning. We dont print warnings by default,
and I<-w> or I<--warning> is used to force warnings.

Table header fields can be specified by regexps ex :

    ((1,*))

It was impossible in B<wwwtable>.

Axis counters are 100% orthogonal. This mean that code :

    (*,1) width=30
    (*,2) width=35
    (*,3) width=40
    (=,=)
    Foo

Foo will appear in 3rd column. If you wanted it to be in 1st
you should write :

    (*,1) width=30
    (*,2) width=35
    (*,3) width=40
    (=,1)
    Foo

or

    (*,) width=30
    (*,+) width=35
    (*,+) width=40
    (=,1)
    Foo

In B<freetable> 2.0 two new methods o specifying cell address
were introduced. They are completely incompatible with B<wwwtable>.

=head1 BUGS

"Arbitrary Perl Code" cell address will fail on very complex Perl code.

=head1 SEE ALSO

B<freetable(1)>

=head1 AUTHOR

Tomasz Wegrzanowski <taw@users.sourceforge.net>

WebMake plugin interface by Justin Mason

=cut

-->

<{perl

  define_preformat_tag ("wwwtable", \&handle_wwwtable_tag, qw());

  sub handle_wwwtable_tag {
    my ($tagname, $attrs, $text, $self) = @_;

    my $tmpf = $self->get_tmp_filename ("wwwtable", "html");
    open (OUT, ">$tmpf") or
		 warn "wwwtable: cannot write to $tmpf\n";

    my $ftargs = '';
    my $attrstr = '';
    foreach my $key (keys %{$attrs}) {
      if ($key eq 'freetableargs') {
	$ftargs = $attrs->{$key}; next;
      }
      $attrstr .= "$key=\"".$attrs->{$key}."\" ";
    }

    print OUT "<wwwtable $attrstr>\n", $text, "\n</wwwtable>\n";
    close OUT or warn "wwwtable: cannot close $tmpf\n";

    if (open (IN, "freetable $ftargs $tmpf |")) {
      $text = join ('', <IN>);
      close IN or warn "wwwtable: 'freetable' command failed\n";
    } else {
      warn "wwwtable: cannot run 'freetable'\n";
      $text = '<!-- freetable tool not found -->';
    }

    return $text;
  }

}>

