<& /elements/select-tiered.html, tiers => [ { field => 'classnum', table => 'hardware_class', hashref => ($classnum ? { classnum => $classnum } : {}), name_col => 'classname', empty_label => '(all)', }, { field => 'model', table => 'hardware_type', select => 'classnum, model', name_col => 'model', value_col => 'model', link_col => 'classnum', hashref => $hashref, extra_sql => 'GROUP BY classnum, model', empty_label => '(all)', }, { table => 'hardware_type', name_col => 'revision', value_col => 'typenum', link_col => 'model', empty_label => $opt{'empty_label'}, }, ], field => 'typenum', %opt, &> <%init> my %opt = @_; my $hashref = $opt{'hashref'} || {}; my $classnum = $hashref->{classnum};