bugfix: when a new answer is saved set fraction to 'null',

fraction cannot be negative (minimum is 0)

Author: KBorm

README.md

@@ -7,7 +7,10 @@ following features:
 - store extra grading information (feedback from grader)
 - avoid regrading when finishing an attempt
 - special handling for internal grading errors
+- whenever a new response is saved (without grading) fraction is set to 'null'
 - optional adaptivenopenalty behaviour
+- adaptivenopenalty behaviour: fraction cannot be negative (minimum is 0)
+
 
 Copyright notice: The coderunner behaviour 
 (https://moodle.org/plugins/qbehaviour_adaptive_adapted_for_coderunner) was used a starting point.   

behaviour.php

@@ -102,6 +102,19 @@ private function get_result_from_grader($response, question_attempt_pending_step
         return $gradedata;
     }
 
+    // we set fraction to null:
+    // scenario to handle:
+    // - right answer with fraction 1
+    // - new answer => unknown result
+    public function process_save(question_attempt_pending_step $pendingstep) {
+        $status = parent::process_save($pendingstep);
+        // + set fraction to null because we need new grading
+        // + in case of a new response
+        $pendingstep->set_fraction(null);
+        return $status;
+    }
+
+
     public function process_submit(question_attempt_pending_step $pendingstep, $compile = false) {
         $status = $this->process_save($pendingstep);
 
@@ -263,7 +276,8 @@ protected function adjusted_fraction($fraction, $prevtries) {
             return $fraction;
         } else {
             if (!is_null($fraction)) {
-                return parent::adjusted_fraction($fraction, $prevtries);
+                // + if adjusted fraction is negative than it is set to 0
+                return max(0, parent::adjusted_fraction($fraction, $prevtries));
             } else {
                 // ???
                 return $fraction;
@@ -285,5 +299,4 @@ public function get_state_string($showcorrectness) {
 
         return parent::get_state_string($showcorrectness);
     }
-
 }

version.php

@@ -23,12 +23,12 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version = 2019091700;
+$plugin->version = 2019101700;
 $plugin->requires = 2016120503;
 $plugin->cron = 0;
 $plugin->component = 'qbehaviour_adaptiveexternalgrading';
 $plugin->maturity = MATURITY_STABLE;
-$plugin->release = '0.9.5';
+$plugin->release = '0.9.6';
 
 $plugin->dependencies = array();