Limited submissions graphs visibility to teachers

views/previoussubmissionslist.php

@@ -58,11 +58,13 @@ if ($detailed) {
 $vpl->print_header( get_string( 'previoussubmissionslist', VPL ) );
 $vpl->print_view_tabs( basename( __FILE__ ) );
 
-$grapher = new vpl_grapher($vpl, $userid);
-$grapher->draw_files_evolution_graph();
-$grapher->draw_working_periods_graph();
-$grapher->draw_files_evolution_graph(true);
-$grapher->draw_daily_activity_graph();
+if ($vpl->has_capability(VPL_GRADE_CAPABILITY)) {
+    $grapher = new vpl_grapher($vpl, $userid);
+    $grapher->draw_files_evolution_graph();
+    $grapher->draw_working_periods_graph();
+    $grapher->draw_files_evolution_graph(true);
+    $grapher->draw_daily_activity_graph();
+}
 
 $table = new html_table();
 $table->head = array (