MDL-79056 gradereport_user: Make column heading IDs unique

Associate column headings of user report tables to the user ID that the
report is being generated for. This will prevent duplicate IDs for the
report columns when multiple user report tables are displayed on the
User report page.

grade/report/user/classes/report/user.php

@@ -445,7 +445,7 @@ private function fill_table_recursive(array &$element) {
         $depth = $element['depth'];
         $gradeobject = $element['object'];
         $eid = $gradeobject->id;
-        $element['userid'] = $this->user->id;
+        $element['userid'] = $userid = $this->user->id;
         $fullname = $this->gtree->get_element_header($element, true, false, true, false, true);
         $data = [];
         $gradeitemdata = [];
@@ -587,7 +587,7 @@ private function fill_table_recursive(array &$element) {
                 if ($this->showweight) {
                     $data['weight']['class'] = $class;
                     $data['weight']['content'] = '-';
-                    $data['weight']['headers'] = "$headercat $headerrow weight";
+                    $data['weight']['headers'] = "$headercat $headerrow weight$userid";
                     // Has a weight assigned, might be extra credit.
 
                     // This obliterates the weight because it provides a more informative description.
@@ -690,7 +690,7 @@ private function fill_table_recursive(array &$element) {
                                 $gradegrade->grade_item, true) . $gradestatus;
                         $gradeitemdata['graderaw'] = $gradeval;
                     }
-                    $data['grade']['headers'] = "$headercat $headerrow grade";
+                    $data['grade']['headers'] = "$headercat $headerrow grade$userid";
                     $gradeitemdata['gradeformatted'] = $data['grade']['content'];
                 }
 
@@ -701,7 +701,7 @@ private function fill_table_recursive(array &$element) {
                         GRADE_DISPLAY_TYPE_REAL,
                         $this->rangedecimals
                     );
-                    $data['range']['headers'] = "$headercat $headerrow range";
+                    $data['range']['headers'] = "$headercat $headerrow range$userid";
 
                     $gradeitemdata['rangeformatted'] = $data['range']['content'];
                     $gradeitemdata['grademin'] = $gradegrade->grade_item->grademin;
@@ -733,7 +733,7 @@ private function fill_table_recursive(array &$element) {
                             GRADE_DISPLAY_TYPE_PERCENTAGE
                         );
                     }
-                    $data['percentage']['headers'] = "$headercat $headerrow percentage";
+                    $data['percentage']['headers'] = "$headercat $headerrow percentage$userid";
                     $gradeitemdata['percentageformatted'] = $data['percentage']['content'];
                 }
 
@@ -763,7 +763,7 @@ private function fill_table_recursive(array &$element) {
                             GRADE_DISPLAY_TYPE_LETTER
                         );
                     }
-                    $data['lettergrade']['headers'] = "$headercat $headerrow lettergrade";
+                    $data['lettergrade']['headers'] = "$headercat $headerrow lettergrade$userid";
                     $gradeitemdata['lettergradeformatted'] = $data['lettergrade']['content'];
                 }
 
@@ -797,7 +797,7 @@ private function fill_table_recursive(array &$element) {
                         $gradeitemdata['rank'] = $rank;
                         $gradeitemdata['numusers'] = $numusers;
                     }
-                    $data['rank']['headers'] = "$headercat $headerrow rank";
+                    $data['rank']['headers'] = "$headercat $headerrow rank$userid";
                 }
 
                 // Average.
@@ -811,7 +811,7 @@ private function fill_table_recursive(array &$element) {
                     } else {
                         $data['average']['content'] = '-';
                     }
-                    $data['average']['headers'] = "$headercat $headerrow average";
+                    $data['average']['headers'] = "$headercat $headerrow average$userid";
                 }
 
                 // Feedback.
@@ -838,13 +838,13 @@ private function fill_table_recursive(array &$element) {
                             ['context' => $gradegrade->get_context()]);
                         $gradeitemdata['feedback'] = $gradegrade->feedback;
                     }
-                    $data['feedback']['headers'] = "$headercat $headerrow feedback";
+                    $data['feedback']['headers'] = "$headercat $headerrow feedback$userid";
                 }
                 // Contribution to the course total column.
                 if ($this->showcontributiontocoursetotal) {
                     $data['contributiontocoursetotal']['class'] = $class;
                     $data['contributiontocoursetotal']['content'] = '-';
-                    $data['contributiontocoursetotal']['headers'] = "$headercat $headerrow contributiontocoursetotal";
+                    $data['contributiontocoursetotal']['headers'] = "$headercat $headerrow contributiontocoursetotal$userid";
 
                 }
                 $this->gradeitemsdata[] = $gradeitemdata;
@@ -1026,9 +1026,10 @@ public function print_table(bool $return = false) {
         ];
 
         // Set the table headings.
+        $userid = $this->user->id;
         foreach ($this->tableheaders as $index => $heading) {
             $headingcell = new \html_table_cell($heading);
-            $headingcell->attributes['id'] = $this->tablecolumns[$index];
+            $headingcell->attributes['id'] = $this->tablecolumns[$index] . $userid;
             $headingcell->attributes['class'] = "header column-{$this->tablecolumns[$index]}";
             if ($index == 0) {
                 $headingcell->colspan = $this->maxdepth;