--- trunk2/lib/WebPAC/Tree.pm	2004/09/14 20:57:58	443
+++ trunk2/lib/WebPAC/Tree.pm	2004/09/15 22:36:23	454
@@ -5,7 +5,6 @@
 
 use Carp;
 use Log::Log4perl qw(get_logger :levels);
-use locale;
 
 =head1 NAME
 
@@ -23,7 +22,7 @@
 
  my @tree = ({
  	# level 0
-	code_arr	=> sub { @{$l->{$_[0]}} },
+	code_arr	=> sub { @{$_[0]} },
 	filter_code	=> sub { shift },
 	lookup_v900	=> sub {
 				my ($c,$p) = @_;
@@ -32,11 +31,10 @@
 			},
 	lookup_term	=> sub { shift @{$l->{"d:".$_[0]}} },
 	lookup_mfn	=> sub { shift @{$l->{"900_mfn:".$_[0]}} },
-	have_children	=> sub { defined($l->{$_[1]}) },
-	child_code	=> sub { return $_[1] },
+	have_children	=> sub { return $l->{$_[1]} },
 	},{
 	# level 1
-	code_arr	=> sub { @{$l->{$_[0]}} },
+	code_arr	=> sub { @{$_[0]} },
 	filter_code	=> sub { shift },
 	lookup_v900	=> sub {
 				my ($c,$p) = @_;
@@ -46,9 +44,12 @@
 	lookup_term	=> sub { shift @{$l->{"d:".$_[0]}} },
 	lookup_mfn	=> sub { shift @{$l->{"900_mfn:".$_[0]}} },
 	have_children	=> sub { 0 },
-	child_code	=> sub { 0 },
  )};
 
+You can, however, create recursion with C<have_children_at_level> discussed
+below, but you loose ability to limit tree depth or to specify different
+style for each level.
+
 Documentation for each element of tree is little sparse, but here it is:
 
 =over 5
@@ -90,15 +91,18 @@
 
 =item have_children
 
-Returns C<true> or C<false> depending if current node have children.
+Returns children for next iteration of tree generation or undef.
+
+ my $next_lvl = $t->{'have_children'}->($code,$v900,$start_code);
 
- if ($t->{'have_children'}->($code,$v900,$start_code)) { ... }
+=item have_children_at_level
 
-=item child_code
+Returns children for next iteration and next level.
 
-Returns child code for next iteration of tree generation.
+ my ($level,$next_lvl) = $t->{'have_children_at_level'}->($code,$v900,$start_code);
 
- my $child_code = $t->{'child_code'}->($code,$v900,$start_code);
+It's safe to return undef just for next level data (C<$next_lvl> in example
+above) to stop recursion.
 
 =back
 
@@ -190,6 +194,8 @@
 
 	my ($level,$start_code) = @_;
 
+	my $next_level = $level + 1;
+
 	my $log = $self->_get_logger();
 
 	$log->logconfess("need level") unless (defined($level));
@@ -226,12 +232,16 @@
 			my ($link_start,$link_end) = ('','');
 	
 			my $have_children = $tree->[$level]->{'have_children'}->($code,$v900,$start_code);
-			if ($have_children) {
-				($link_start,$link_end) = (qq{<a href="#mfn$mfn" onClick="return toggle_display('id$mfn');">},qq{</a>});
-			} else {
+
+			if (! $have_children) {
 				$log->debug("# $level doesn't have_children($code,$v900,$start_code)");
+				($next_level,$have_children) = $tree->[$level]->{'have_children_at_level'}->($code,$v900,$start_code) if ($tree->[$level]->{'have_children_at_level'});
+				$log->debug("# $level have_children($code,$v900,$start_code) on level $next_level") if ($have_children);
+
 			}
 
+			($link_start,$link_end) = (qq{<a href="#mfn$mfn" onClick="return toggle_display('id$mfn');">},qq{</a>}) if ($have_children);
+
 			my $mfn_link = "thes/$mfn.html";
 			if (-e "out/$mfn_link") {
 				$html .= " " x $level .
@@ -262,7 +272,7 @@
 				push @{$self->{'show_ids'}}, "id$mfn";
 			}
 
-			$html .= $self->unroll($level+1, $tree->[$level]->{'child_code'}->($code,$v900,$start_code));
+			$html .= $self->unroll($next_level, $have_children);
 			
 			$html .= " " x $level . qq{</ul>\n};