Exchange $_REQUEST for a Moodle native function dealing with the supe…

…r globals

export.php

@@ -53,13 +53,13 @@
 
 $questionlist = [];
 
-// There is not request class to actually get the posted params. The checked checboxed
-// have a name like q<ID> where <ID> is the question id.
-if (is_array($_REQUEST)) {
-    foreach (array_keys($_REQUEST) as $key) {
+// The checked checkboxes have a name like q<ID> where <ID> is the question id.
+$request = data_submitted();
+if ($request) {
+    foreach (array_keys(get_object_vars($request)) as $key) {
         if (strpos($key, 'q') === 0) {
-            $questionid = substr($key, 1);
-            if (is_number($questionid)) {
+            $questionid = (int)substr($key, 1);
+            if ($questionid > 0) {
                 $question = question_bank::load_question_data($questionid);
                 $questiondata = question_bank::load_question_data($questionid);
                 question_require_capability_on($questiondata, 'view');