%# BEGIN BPS TAGGED BLOCK {{{
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%# LICENSE:
%#
%# This work is made available to you under the terms of Version 2 of
%# the GNU General Public License. A copy of that license should have
%# been provided with this software, but in any event can be snarfed
%# from www.gnu.org.
%#
%# This work is distributed in the hope that it will be useful, but
%# WITHOUT ANY WARRANTY; without even the implied warranty of
%# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
%# General Public License for more details.
%#
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%# along with this program; if not, write to the Free Software
%# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
%# 02110-1301 or visit their web page on the internet at
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<& /Elements/Header, Title => loc('Browse by topic') &>
<& /Elements/Tabs &>

<& /Elements/ListActions, actions => \@Actions &>
<a href="Topics.html"><&|/l&>All topics</&></a>
% if (defined $class) {
&gt; <a href="Topics.html?class=<%$currclass_id%>"><% $currclass_name %></a>
% }

% if ($id != 0) {
&gt; <& /Articles/Elements/ShowTopic, topic => $currtopic &>
% }
<br />
<h1><&|/l&>Browse by topic</&></h1>
<%perl>
if (defined $class) {
   $m->print('<h2>'.'<a href="'.
   RT->Config->Get('WebPath')."/Articles/Topics.html?class=" . $currclass_id
   .'">'.$currclass_name."</a></h2>\n");
   ProduceTree(\@Actions, $currclass, $currclass_id, $currclass_name, 0, $id);
} else {
    $m->print("<ul>\n");
    while (my $c = $Classes->Next) {
        $m->print('<li><h2>'.'<a href="'.
        RT->Config->Get('WebPath')."/Articles/Topics.html?class=" . $c->Id
        .'">'.$c->Name."</a></h2>\n");
        $m->print("\n</li>\n");
    }
    $m->print(qq|<li><h2><a href="|.RT->Config->Get('WebPath').qq|/Articles/Topics.html?class=0">|.loc('Global Topics').qq|</a></h2></li>\n|);
    $m->print("</ul>\n");
}
</%perl>

<br />
<%perl>
my @articles;
if ($id or $showall) {
    my $Articles = RT::ObjectTopics->new($session{'CurrentUser'});
    $Articles->Limit(FIELD => 'ObjectType', VALUE => 'RT::Article');
    if ($id) {
        $Articles->Limit(FIELD => 'Topic', VALUE => $id, ENTRYAGGREGATOR => 'OR');
        if ($showall) {
            my $kids = $currtopic->Children;
            while (my $k = $kids->Next) {
                $Articles->Limit(FIELD => 'Topic', VALUE => $k->Id,
                                 ENTRYAGGREGATOR => 'OR');
            }
        }
    }
    @articles = map {$a = RT::Article->new($session{'CurrentUser'}); $a->Load($_->ObjectId); $a} @{$Articles->ItemsArrayRef}
} elsif ($class) {
    my $Articles = RT::Articles->new($session{'CurrentUser'});
    my $TopicsAlias = $Articles->Join(
        TYPE   => 'left',
        ALIAS1 => 'main',
        FIELD1 => 'id',
        TABLE2 => 'ObjectTopics',
        FIELD2 => 'ObjectId',
    );
    $Articles->Limit(
        LEFTJOIN => $TopicsAlias,
        FIELD    => 'ObjectType',
        VALUE    => 'RT::Article',
    );
    $Articles->Limit(
        ALIAS      => $TopicsAlias,
        FIELD      => 'Topic',
        OPERATOR   => 'IS',
        VALUE      => 'NULL',
        QUOTEVALUE => 0,
    );
    $Articles->Limit(
        FIELD      => 'Class',
        OPERATOR   => '=',
        VALUE      => $class,
    );
    @articles = @{$Articles->ItemsArrayRef};
}
</%perl>

% if (@articles) {
%   if ($id) {
<h2><&|/l, $currtopic->Name&>Articles in [_1]</&></h2>
%   } elsif ($class) {
<h2><&|/l&>Articles with no topics</&></h2>
%   }
<ul>
%   for my $a (@articles) {
<li><a href="Article/Display.html?id=<% $a->Id %>"><% $a->Name || loc("(no name)") %></a></li>
%   }
</ul>
% }

<%init>
my @Actions;
my $Classes;
my $currclass;
my $currclass_id;
my $currclass_name;
my $currtopic;

if ( defined $class ) {
    if ($class) {
        $currclass = RT::Class->new( $session{'CurrentUser'} );
        $currclass->Load($class);
        $currclass_id   = $currclass->Id;
        $currclass_name = $currclass->Name;
    } else {
        $currclass      = $RT::System;
        $currclass_id   = 0;
        $currclass_name = 'Global Topics';
    }
} else {
    $Classes = RT::Classes->new( $session{'CurrentUser'} );
    $Classes->LimitToEnabled();
}

if ($id) {
    $currtopic = RT::Topic->new( $session{'CurrentUser'} );
    $currtopic->Load($id);
}

# A subroutine that iterates through topics and their children, producing
# the necessary ul, li, and href links for the table of contents.  Thank
# heaven for query caching.  The $restrict variable is used to display only
# the branch of the hierarchy which contains that topic ID.

sub ProduceTree {
    my ( $Actions, $currclass, $currclass_id, $currclass_name, $parentid, $restrictid ) = @_;
    $parentid = 0 unless $parentid;

    # Deal with tree restriction, if any.
    if ($restrictid) {
        my $rtopic = RT::Topic->new( $session{'CurrentUser'} );
        $rtopic->Load($restrictid);
        unless ( $rtopic->Id()
            && $rtopic->ObjectId() == $currclass_id )
        {
            push( @{$Actions},"Could not restrict view to topic $restrictid");

            # Start over, without the restriction.
            &ProduceTree( $Actions, $currclass, $currclass_id, $currclass_name, $parentid, undef );
        } else {
            my @showtopics;
            push( @showtopics, $rtopic );
            my $parent = $rtopic->ParentObj;
            while ( $parent->Id ) {
                push( @showtopics, $parent );
                my $newparent = $parent->ParentObj;
                $parent = $newparent;
            }

            # List the topics.
            my $indents = @showtopics;
            while ( my $t = pop @showtopics ) {
                print "<ul>";
                print &MakeLinks( $t, $currclass, $currclass_id, $currclass_name, $t->Children->Count );
                if ( $t->Id == $restrictid ) {
                    &ProduceTree( $Actions, $currclass, $currclass_id, $currclass_name, $restrictid, undef );
                }
            }
            print "</ul>" x $indents;
        }
    } else {

        # No restriction in place.  Build the entire tree.
        my $topics = RT::Topics->new( $session{'CurrentUser'} );
        $topics->LimitToObject($currclass);
        $topics->LimitToKids($parentid);
        $topics->OrderBy( FIELD => 'Name' );
        print "<ul>" if $topics->Count;
        while ( my $t = $topics->Next ) {
            if ( $t->Children->Count ) {
                print &MakeLinks( $t, $currclass, $currclass_id, $currclass_name, 1 );
                &ProduceTree( $Actions, $currclass, $currclass_id, $currclass_name, $t->Id );
            } else {
                print &MakeLinks( $t, $currclass, $currclass_id, $currclass_name, 0 );
            }
        }
        print "</ul>\n" if $topics->Count;
    }
}

sub MakeLinks {
    my ( $topic, $currclass, $currclass_id, $currclass_name, $haschild ) = @_;
    my $query;
    my $output;

    if ( ref($topic) eq 'RT::Topic' ) {

        my $topic_info = $topic->Name() || loc("(no name)");
        $topic_info .= ": " . $topic->Description() if $topic->Description;

        if ($haschild) { # has topics below it
            $query  = "Topics.html?id=" . $topic->Id . "&class=" . $currclass_id;
            $output = qq(<li><a href="$query">$topic_info</a>);
        } else {
            $output = qq(<li>$topic_info);
        }

        my $Articles = RT::ObjectTopics->new( $session{'CurrentUser'} );
        $Articles->Limit( FIELD => 'ObjectType', VALUE => 'RT::Article' );
        $Articles->Limit( FIELD => 'Topic',      VALUE => $topic->Id );
        if ( $Articles->Count ) {
            my $article_text = " (" . loc( "[quant,_1,article]", $Articles->Count ) . ")";
            my $query  = "Topics.html?id=" . $topic->Id . "&class=$currclass_id&showall=1";
            $output .= qq(<a href="$query">$article_text</a>);
        }

        $output .= "</li>\n";

    } else {

        # This builds a link for the class specified, with no particular topic.
        $query  = "Topics.html?class=" . $currclass_id;
        $output = "<li><a href=\"$query\">" . $currclass_name . "</a>";
        $output .= ": " . $currclass->Description if $currclass->Description;
    }

    return $output;
}

</%init>

<%args>
$id => 0
$class => undef
$showall => undef
</%args>