Added route, which let's you download all data as csv.

app/Http/Controllers/ResultController.php

@@ -6,6 +6,8 @@ use App\Experiment;
 use App\Result;
 use App\Logic\IPAnonymizer;
 
+use League\Csv\Writer;
+
 use Illuminate\Http\Request;
 use Str;
 use Log;
@@ -84,6 +86,58 @@ class ResultController extends Controller
         ]);
     }
 
+    // Returns object obj with obj->header: array with header info
+    //                         obj->rows: arrays with data.
+    //
+    // @param $results Collection of Result
+    private function getResults($results) {
+        $header = collect($results->first()->data ?? [])
+            ->map(function($entry) {
+                return array_keys($entry);
+            })
+            ->flatten()
+            ->unique();
+
+        $all_rows = collect();
+
+        foreach ($results as $result) {
+            $rows = collect($result->data ?? [])
+                ->map(function($row) use ($header) {
+                    foreach ($header as $key) {
+                        // Fill empty columns with N/A
+                        $row[$key] = $row[$key] ?? config('experiment.n-a-text');
+
+                        // Replace arrays with json
+                        if (is_array($row[$key]))
+                            $row[$key] = json_encode($row[$key]);
+                    }
+
+                    return $row;
+                });
+
+            $all_rows = $all_rows->concat($rows);
+        }
+
+        return (object) [
+            'header' => $header->toArray(),
+            'rows' => $all_rows->toArray(),
+        ];
+    }
+
+    public function showAllCSV() {
+        header('Content-Type: text/csv; charset=utf-8');
+        header('Content-Type: application/force-download');
+        header('Content-Disposition: attachment; filename=results.csv');
+
+        $data = $this->getResults(Result::all());
+
+        $csv = Writer::createFromString('');
+        $csv->insertOne($data->header);
+        $csv->insertAll($data->rows);
+
+        return $csv->getContent();
+    }
+
     /**
      * Display the result as json.
      */

resources/views/results/index.blade.php

@@ -56,4 +56,6 @@
     </tbody>
 </table>
 
+<a href="{{ route('results.show-all-csv') }}">Download all results as CSV</a>
+
 @endsection

routes/web.php

@@ -22,6 +22,9 @@ Route::middleware(['web', 'auth'])->group(function() {
 
     Route::get('/admin/results/show-json/{result}', 'ResultController@showJson')
         ->name('results.show-json');
+    Route::get('/admin/results/show-all-csv', 'ResultController@showAllCSV')
+        ->name('results.show-all-csv');
+
     Route::get('/admin/results/partial', 'ResultController@indexPartial')
         ->name('results.index.partial');
     Route::resource('/admin/results', 'ResultController');