Having done this sort of tree before, I know it is tougher to code than it first sounds. The following code prints out appoximately what you asked for in the command line, and should be fairly easily be tweaked to your needs. The hash is just there to emulate the database I don't have.

The main thing that is done is that all the replies at any given level are queried before getting their children. This allows us to check whether to make the pipes downward, or just leave whitespace. HTH Dave 
#!perl 
use strict;


my @RootArticles = ("ArtA", "ArtB", "ArtC");
my %Children = (
        "ArtA" => "ArtD|ArtE|ArtF",
        "ArtE" => "ArtG|ArtH",
        "ArtC" => "ArtI|ArtJ",
        "ArtI" => "ArtK",
        "ArtK" => "ArtL",
           );
foreach (@RootArticles) {
    &Printout ("", $_);
    &getarticles("", $_);
}

sub getarticles {
    my $IndentString = shift;
        my $article = shift;
    my @Replies = ();
        foreach (split(/\|/, $Children{$article})) {
        push (@Replies, $_);
        }
    while (my $reply = pop(@Replies)) {
        &Printout($IndentString . '`---', $reply);
        my $NewIndent = (@Replies)?"|   ":"    ";
        &getarticles( $NewIndent . $IndentString, $reply);
    }
        return 1;
}

sub Printout {
    my ($IndentString, $String) = @_;
    print "$IndentString$String\n";
}

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In reply to Re: Graphical Hierarchical Tree by dfog
in thread Graphical Hierarchical Tree by yojimbo

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