MDL-66136 assign: Verify presence of resources in online text submission

Author: Mihail Geshoski

mod/assign/submission/onlinetext/locallib.php

@@ -599,12 +599,17 @@ public function delete_instance() {
     public function is_empty(stdClass $submission) {
         $onlinetextsubmission = $this->get_onlinetext_submission($submission->id);
         $wordcount = 0;
+        $hasinsertedresources = false;
 
         if (isset($onlinetextsubmission->onlinetext)) {
             $wordcount = count_words(trim($onlinetextsubmission->onlinetext));
+            // Check if the online text submission contains video, audio or image elements
+            // that can be ignored and stripped by count_words().
+            $hasinsertedresources = preg_match('/<\s*((video|audio)[^>]*>(.*?)<\s*\/\s*(video|audio)>)|(img[^>]*>(.*?))/',
+                    trim($onlinetextsubmission->onlinetext));
         }
 
-        return $wordcount == 0;
+        return $wordcount == 0 && !$hasinsertedresources;
     }
 
     /**
@@ -621,12 +626,17 @@ public function submission_is_empty(stdClass $data) {
             return true;
         }
         $wordcount = 0;
+        $hasinsertedresources = false;
 
         if (isset($data->onlinetext_editor['text'])) {
             $wordcount = count_words(trim((string)$data->onlinetext_editor['text']));
+            // Check if the online text submission contains video, audio or image elements
+            // that can be ignored and stripped by count_words().
+            $hasinsertedresources = preg_match('/<\s*((video|audio)[^>]*>(.*?)<\s*\/\s*(video|audio)>)|(img[^>]*>(.*?))/',
+                    trim((string)$data->onlinetext_editor['text']));
         }
 
-        return $wordcount == 0;
+        return $wordcount == 0 && !$hasinsertedresources;
     }
 
     /**