MDL-19054 quiz/report/statistics: Add chart statistics to multiple ch…

…oice questions

mod/quiz/report/statistics/report.php

@@ -28,6 +28,8 @@
 use core_question\statistics\responses\analyser;
 use mod_quiz\local\reports\report_base;
 use core_question\statistics\questions\all_calculated_for_qubaid_condition;
+use core\chart_pie;
+use core\chart_series;
 
 require_once($CFG->dirroot . '/mod/quiz/report/reportlib.php');
 require_once($CFG->dirroot . '/mod/quiz/report/statistics/statistics_form.php');
@@ -432,7 +434,7 @@ protected function output_individual_question_response_analysis($question, $vari
         if ($this->table->is_downloading()) {
             $exportclass->output_headers($qtable->headers);
         }
-
+        $chartdata = [];
         // Where no variant no is specified the variant no is actually one.
         if ($variantno === null) {
             $variantno = 1;
@@ -442,13 +444,29 @@ protected function output_individual_question_response_analysis($question, $vari
             foreach ($subpart->get_response_class_ids() as $responseclassid) {
                 $responseclass = $subpart->get_response_class($responseclassid);
                 $tabledata = $responseclass->data_for_question_response_table($subpart->has_multiple_response_classes(), $partid);
+                $chartdata[] = ['label'=> $tabledata[0]->response, 'value' => $tabledata[0]->totalcount ];
                 foreach ($tabledata as $row) {
                     $qtable->add_data_keyed($qtable->format_row($row));
                 }
             }
         }
 
         $qtable->finish_output(!$this->table->is_downloading());
+
+        // Extract labels and counts
+        $labels = array_column($chartdata, 'label');
+        $counts = array_column($chartdata, 'value');
+
+        // Create the chart
+        $chart = new chart_pie();
+        $series = new chart_series('Quiz Results', $counts);
+
+        // Add series and labels
+        $chart->add_series($series);
+        $chart->set_labels($labels);
+
+        // Render the chart in the report page
+        echo $OUTPUT->render($chart);
     }
 
     /**