filter out students without submitted solutions, re #42

controllers/solutions.php

@@ -418,9 +418,6 @@ class SolutionsController extends StudipController
             $widget->addLink(_vips('Punktetabelle exportieren'),
                 $this->url_for('solutions/assignment_solutions', ['assignment_id' => $assignment_id, 'format' => 'csv']),
                 Icon::create('download'));
-            $widget->addLink(_vips('Lösungen der Teilnehmer exportieren'),
-                $this->url_for('solutions/download_responses', ['assignment_id' => $assignment_id]),
-                Icon::create('download'));
 
             if ($assignment->type === 'exam') {
                 $widget->addLink(_vips('Abgabeprotokolle exportieren'),
@@ -428,6 +425,9 @@ class SolutionsController extends StudipController
                     Icon::create('download'));
             }
 
+            $widget->addLink(_vips('Lösungen der Teilnehmer exportieren'),
+                $this->url_for('solutions/download_responses', ['assignment_id' => $assignment_id]),
+                Icon::create('download'));
             $widget->addLink(_vips('Abgegebene Dateien herunterladen'),
                 $this->url_for('solutions/download_all_uploads', ['assignment_id' => $assignment_id]),
                 Icon::create('download'));
@@ -510,12 +510,14 @@ class SolutionsController extends StudipController
 
         foreach ($arrays['solvers'] as $solver) {
             $row = [$solver['name']];
+            $has_solution = false;
 
             foreach ($arrays['exercises'] as $exercise) {
                 $solution = $arrays['solutions'][$solver['id']][$exercise['id']];  // may be null
                 $export = [];
 
                 if ($solution) {
+                    $has_solution = true;
                     $response = VipsSolution::find($solution['id'])->response;
                     $export = $exercises[$exercise['id']]->exportResponse($response);
                 }
@@ -525,8 +527,10 @@ class SolutionsController extends StudipController
                 }
             }
 
+            if ($has_solution) {
                 $data[] = $row;
             }
+        }
 
         $this->render_csv($data, $assignment->test->title . '.csv');
     }