diff --git a/db/install.xml b/db/install.xml
index 817bccc13..f50087fd2 100644
--- a/db/install.xml
+++ b/db/install.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<XMLDB PATH="question/type/coderunner/db" VERSION="20201207" COMMENT="XMLDB file for Moodle question/type/coderunner"
+<XMLDB PATH="question/type/coderunner/db" VERSION="20201215" COMMENT="XMLDB file for Moodle question/type/coderunner"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="../../../../lib/xmldb/xmldb.xsd"
 >
@@ -31,6 +31,8 @@
         <FIELD NAME="pertesttemplate" TYPE="text" NOTNULL="false" SEQUENCE="false" COMMENT="DEFUNCT: A template to build a test run for each test case. Required."/>
         <FIELD NAME="templateparams" TYPE="text" NOTNULL="false" SEQUENCE="false" COMMENT="A json-encoded record of extra parameters to pass to the template engine when building the source code to be executed."/>
         <FIELD NAME="templateparamslang" TYPE="char" LENGTH="50" NOTNULL="false" DEFAULT="twig" SEQUENCE="false" COMMENT="The language in which the template parameters are defined."/>
+        <FIELD NAME="templateparamsevalpertry" TYPE="int" LENGTH="1" NOTNULL="false" DEFAULT="0" SEQUENCE="false" COMMENT="Set true to re-evaluate the template parameters every time on every new question attempt. Essential for randomisation or if the Student variable is used. Not relevant if templateparamslang is None (no evaluation) or Twig (runs on Moodle and re-evaluates)"/>
+        <FIELD NAME="templateparamsevald" TYPE="text" NOTNULL="false" SEQUENCE="false" COMMENT="The evaluated template parameters (JSON) if templateparamslang is neither None nor Twig and templateparamsevaleverytry is false."/>
         <FIELD NAME="hoisttemplateparams" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="True to hoist templateparams into Twig global namespace."/>
         <FIELD NAME="twigall" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="True to apply Twig macro expansion to question text and testcases."/>
         <FIELD NAME="language" TYPE="char" LENGTH="255" NOTNULL="false" SEQUENCE="false" COMMENT="The programming language, to be passed to the sandbox"/>
diff --git a/db/upgrade.php b/db/upgrade.php
index 0464f3a41..2f7b9c47d 100644
--- a/db/upgrade.php
+++ b/db/upgrade.php
@@ -342,7 +342,7 @@ function xmldb_qtype_coderunner_upgrade($oldversion) {
 
         // Define field templateparamslang to be added to question_coderunner_options.
         $table = new xmldb_table('question_coderunner_options');
-        $field = new xmldb_field('templateparamslang', XMLDB_TYPE_CHAR, '50', null, null, null, 'twig', 'templateparams');
+        $field = new xmldb_field('templateparamslang', XMLDB_TYPE_CHAR, '50', null, null, null, 'None', 'templateparams');
 
         // Conditionally launch add field templateparamslang.
         if (!$dbman->field_exists($table, $field)) {
@@ -353,6 +353,26 @@ function xmldb_qtype_coderunner_upgrade($oldversion) {
         upgrade_plugin_savepoint(true, 2020120701, 'qtype', 'coderunner');
     }
 
+    if ($oldversion < 2020121501) {
+        $table = new xmldb_table('question_coderunner_options');
+        $field = new xmldb_field('templateparamsevalpertry', XMLDB_TYPE_INTEGER, '1', null, null, null, '0', 'templateparamslang');
+
+        // Conditionally launch add field templateparamsevalpertry.
+        if (!$dbman->field_exists($table, $field)) {
+            $dbman->add_field($table, $field);
+        }
+        
+        $field = new xmldb_field('templateparamsevald', XMLDB_TYPE_TEXT, null, null, null, null, null, 'templateparamsevalpertry');
+
+        // Conditionally launch add field templateparamsevald.
+        if (!$dbman->field_exists($table, $field)) {
+            $dbman->add_field($table, $field);
+        }
+
+
+        // Coderunner savepoint reached.
+        upgrade_plugin_savepoint(true, 2020121501, 'qtype', 'coderunner');        
+    }
     require_once(__DIR__ . '/upgradelib.php');
     update_question_types();
 
diff --git a/edit_coderunner_form.php b/edit_coderunner_form.php
index 9acc36011..c26501085 100644
--- a/edit_coderunner_form.php
+++ b/edit_coderunner_form.php
@@ -61,18 +61,7 @@ protected function definition() {
         global $PAGE;
 
         $mform = $this->_form;
-        $this->mergedtemplateparams = '';
-        $this->twiggedparams = '';
-        if (!empty($this->question->options->mergedtemplateparams)) {
-            $this->mergedtemplateparams = $this->question->options->mergedtemplateparams;
-            try {
-                $this->twiggedparams = $this->twig_render($this->mergedtemplateparams);
-            } catch (Exception $ex) {
-                // If the params are broken, don't use them.
-                // Code checker won't accept an empty catch.
-                $this->twiggedparams = '';
-            }
-        }
+        
         if (!empty($this->question->options->language)) {
             $this->lang = $this->acelang = $this->question->options->language;
         } else {
@@ -186,6 +175,15 @@ public function definition_inner($mform) {
                 $mform->setDefault('maxfilesize', '10240');
         $mform->disabledIf('maxfilesize', 'attachments', 'eq', 0);
     }
+    
+    
+    function get_data() {
+        $fields = parent::get_data();
+        if ($fields) {
+            $fields->templateparamsevald = $this->formquestion->templateparamsevald;
+        }
+        return $fields;
+    }
 
     /**
      * Add a field for a sample answer to this problem (optional)
@@ -196,10 +194,14 @@ protected function add_sample_answer_field($mform) {
         $mform->addElement('header', 'answerhdr',
                     get_string('answer', 'qtype_coderunner'), '');
         $mform->setExpanded('answerhdr', 1);
+        
+        // Cut out the next line and the use of jsonparams in data-params
+        // once UI plugin parameters have been refactored properly.
+        $jsonparams = $this->get_merged_params();
         $attributes = array(
             'rows' => 9,
             'class' => 'answer edit_code',
-            'data-params' => $this->twiggedparams,
+            'data-params' => $jsonparams,
             'data-lang' => $this->acelang);
         $mform->addElement('textarea', 'answer',
                 get_string('answer', 'qtype_coderunner'),
@@ -231,12 +233,12 @@ protected function add_sample_answer_field($mform) {
     protected function add_preload_answer_field($mform) {
         $mform->addElement('header', 'answerpreloadhdr',
                     get_string('answerpreload', 'qtype_coderunner'), '');
-        $expanded = !empty($this->question->options->answerpreload);
+        $expanded = !empty($this->formquestion->options->answerpreload);
         $mform->setExpanded('answerpreloadhdr', $expanded);
         $attributes = array(
             'rows' => 5,
             'class' => 'preloadanswer edit_code',
-            'data-params' => $this->twiggedparams,
+            //'data-params' => $this->twiggedparams,
             'data-lang' => $this->acelang);
         $mform->addElement('textarea', 'answerpreload',
                 get_string('answerpreload', 'qtype_coderunner'),
@@ -473,123 +475,7 @@ private function newline_hack($s) {
     }
 
 
-    public function validation($data, $files) {
-        $errors = parent::validation($data, $files);
-        $this->question = $this->make_question_from_form_data($data);
-        if ($data['coderunnertype'] == 'Undefined') {
-            $errors['coderunner_type_group'] = get_string('questiontype_required', 'qtype_coderunner');
-        }
-        if ($data['cputimelimitsecs'] != '' &&
-             (!ctype_digit($data['cputimelimitsecs']) || intval($data['cputimelimitsecs']) <= 0)) {
-            $errors['sandboxcontrols'] = get_string('badcputime', 'qtype_coderunner');
-        }
-        if ($data['memlimitmb'] != '' &&
-             (!ctype_digit($data['memlimitmb']) || intval($data['memlimitmb']) < 0)) {
-            $errors['sandboxcontrols'] = get_string('badmemlimit', 'qtype_coderunner');
-        }
-
-        if ($data['precheck'] == constants::PRECHECK_EXAMPLES && $this->num_examples($data) === 0) {
-            $errors['coderunner_precheck_group'] = get_string('precheckingemptyset', 'qtype_coderunner');
-        }
-
-        if ($data['sandboxparams'] != '' &&
-                json_decode($data['sandboxparams']) === null) {
-            $errors['sandboxcontrols'] = get_string('badsandboxparams', 'qtype_coderunner');
-        }
-
-        $templateerrors = $this->validate_template_params($data);
-        if ($templateerrors) {
-            $errors['templateparams'] = $templateerrors;
-        }
-
-        if ($data['prototypetype'] == 0 && ($data['grader'] !== 'TemplateGrader'
-                || $data['iscombinatortemplate'] === false)) {
-            // Unless it's a prototype or uses a combinator-template grader,
-            // it needs at least one testcase.
-            $testcaseerrors = $this->validate_test_cases($data);
-            $errors = array_merge($errors, $testcaseerrors);
-        }
-
-        if ($data['iscombinatortemplate'] && empty($data['testsplitterre'])) {
-            $errors['templatecontrols'] = get_string('bad_empty_splitter', 'qtype_coderunner');
-        }
-
-        if ($data['prototypetype'] == 2 && ($data['saved_prototype_type'] != 2 ||
-                   $data['typename'] != $data['coderunnertype'])) {
-            // User-defined prototype, either newly created or undergoing a name change.
-            $typename = trim($data['typename']);
-            if ($typename === '') {
-                $errors['prototypecontrols'] = get_string('empty_new_prototype_name', 'qtype_coderunner');
-            } else if (!$this->is_valid_new_type($typename)) {
-                $errors['prototypecontrols'] = get_string('bad_new_prototype_name', 'qtype_coderunner');
-            }
-        }
-
-        $penaltyregimeerror = $this->validate_penalty_regime($data);
-        if ($penaltyregimeerror) {
-             $errors['markinggroup'] = $penaltyregimeerror;
-        }
-
-        $resultcolumnsjson = trim($data['resultcolumns']);
-        if ($resultcolumnsjson !== '') {
-            $resultcolumns = json_decode($resultcolumnsjson);
-            if ($resultcolumns === null) {
-                $errors['resultcolumns'] = get_string('resultcolumnsnotjson', 'qtype_coderunner');
-            } else if (!is_array($resultcolumns)) {
-                $errors['resultcolumns'] = get_string('resultcolumnsnotlist', 'qtype_coderunner');
-            } else {
-                foreach ($resultcolumns as $col) {
-                    if (!is_array($col) || count($col) < 2) {
-                        $errors['resultcolumns'] = get_string('resultcolumnspecbad', 'qtype_coderunner');
-                        break;
-                    }
-                    foreach ($col as $el) {
-                        if (!is_string($el)) {
-                            $errors['resultcolumns'] = get_string('resultcolumnspecbad', 'qtype_coderunner');
-                            break;
-                        }
-                    }
-                }
-            }
-        }
-
-        if ($data['attachments']) {
-            // Check a valid regular expression was given.
-            // Use '=' as the PCRE delimiter.
-            if (@preg_match('=^' . $data['filenamesregex'] . '$=', null) === false) {
-                $errors['filenamesgroup'] = get_string('badfilenamesregex', 'qtype_coderunner');
-            }
-        }
-
-        if (count($errors) == 0) {
-            $errors = $this->validate_twigables();
-        }
-
-        if (count($errors) == 0 && !empty($data['validateonsave'])) {
-            $testresult = $this->validate_sample_answer($data);
-            if ($testresult) {
-                $errors['answer'] = $testresult;
-            }
-        }
-
-        $acelangs = trim($data['acelang']);
-        if ($acelangs !== '' && strpos($acelangs, ',') !== false) {
-            $parsedlangs = qtype_coderunner_util::extract_languages($acelangs);
-            if ($parsedlangs === false) {
-                $errors['languages'] = get_string('multipledefaults', 'qtype_coderunner');
-            } else if (count($parsedlangs[0]) === 0) {
-                $errors['languages'] = get_string('badacelangstring', 'qtype_coderunner');
-            }
-        }
-
-        // Don't allow the teacher to require more attachments than they allow; as this would
-        // create a condition that it's impossible for the student to meet.
-        if ($data['attachments'] != -1 && $data['attachments'] < $data['attachmentsrequired'] ) {
-            $errors['attachmentsrequired']  = get_string('mustrequirefewer', 'qtype_coderunner');
-        }
-
-        return $errors;
-    }
+    
 
     // FUNCTIONS TO BUILD PARTS OF THE MAIN FORM
     // =========================================.
@@ -603,6 +489,7 @@ private function make_error_div($mform) {
     // Add to the supplied $mform the panel "Coderunner question type".
     private function make_questiontype_panel($mform) {
         list($languages, $types) = $this->get_languages_and_types();
+        $hidemethod = method_exists($mform, 'hideIf') ? 'hideIf' : 'disabledIf';
 
         $mform->addElement('header', 'questiontypeheader', get_string('type_header', 'qtype_coderunner'));
         // Insert the (possible) missing prototype message as a hidden field. JavaScript
@@ -610,7 +497,7 @@ private function make_questiontype_panel($mform) {
         $mform->addElement('hidden', 'missingprototypemessage', '',
                 array('id' => 'id_missing_prototype', 'class' => 'missingprototypeerror'));
         $mform->setType('missingprototypemessage', PARAM_RAW);
-
+        
         // The Question Type controls (a group with just a single member).
         $typeselectorelements = array();
         $expandedtypes = array_merge(array('Undefined' => 'Undefined'), $types);
@@ -701,11 +588,26 @@ private function make_questiontype_panel($mform) {
                 get_string('hoisttemplateparams', 'qtype_coderunner'));
         $twigelements[] = $mform->createElement('advcheckbox', 'twigall', null,
                 get_string('twigall', 'qtype_coderunner'));
-        $templateparamlangs = array('twig'=>'Twig', 'python'=>'Python (EXPERIMENTAL)');
+        $templateparamlangs = array('None'=>'None',
+            'twig'=>'Twig',
+            'python3'=>'Python3',
+            'c' => 'C',
+            'cpp' => 'C++',
+            'java' => 'Java',
+            'php' => 'php',
+            'pascal' => 'Pascal'
+            );
         $twigelements[] = $mform->createElement('select', 'templateparamslang', get_string('templateparamslang', 'qtype_coderunner'), $templateparamlangs);
+        $twigelements[] = $mform->createElement('advcheckbox', 'templateparamsevalpertry', null,
+                get_string('templateparamsevalpertry', 'qtype_coderunner'));
         $mform->addElement('group', 'twigcontrols', get_string('twigcontrols', 'qtype_coderunner'),
                 $twigelements, null, false);
+        $mform->setDefault('templateparamslang', 'None');
+        $mform->setDefault('templateparamsevalpertry', false);
         $mform->setDefault('twigall', false);
+        $mform->$hidemethod('templateparamsevalpertry', 'templateparamslang', 'eq', 'None');
+        $mform->$hidemethod('templateparamsevalpertry', 'templateparamslang', 'eq', 'twig');
+        
         // Although hoisttemplateparams defaults to true in the database,
         // it defaults to true in this form. This ensures that legacy questions are
         // not affected, while new questions default to true.
@@ -881,115 +783,156 @@ private function make_advanced_customisation_panel($mform) {
         $mform->disabledIf('testsplitterre', 'iscombinatortemplate', 'eq', 0);
         $mform->disabledIf('allowmultiplestdins', 'iscombinatortemplate', 'eq', 0);
     }
+    
+    
+  
+    // **********************************************************
+    //
+    // VALIDATION
+    //
+    // **********************************************************
+    
 
-    // UTILITY FUNCTIONS.
-    // =================.
+    // Validate the given data and possible files.
+    public function validation($data, $files) {
+        $errors = parent::validation($data, $files);
+        $this->formquestion = $this->make_question_from_form_data($data);
+        if ($data['coderunnertype'] == 'Undefined') {
+            $errors['coderunner_type_group'] = get_string('questiontype_required', 'qtype_coderunner');
+        }
+        if ($data['cputimelimitsecs'] != '' &&
+             (!ctype_digit($data['cputimelimitsecs']) || intval($data['cputimelimitsecs']) <= 0)) {
+            $errors['sandboxcontrols'] = get_string('badcputime', 'qtype_coderunner');
+        }
+        if ($data['memlimitmb'] != '' &&
+             (!ctype_digit($data['memlimitmb']) || intval($data['memlimitmb']) < 0)) {
+            $errors['sandboxcontrols'] = get_string('badmemlimit', 'qtype_coderunner');
+        }
 
-    // True iff the given name is valid for a new type, i.e., it's not in use
-    // in the current context (Currently only a single global context is
-    // implemented).
-    private function is_valid_new_type($typename) {
-        list($langs, $types) = $this->get_languages_and_types();
-        return !array_key_exists($typename, $types);
-    }
+        if ($data['precheck'] == constants::PRECHECK_EXAMPLES && $this->num_examples($data) === 0) {
+            $errors['coderunner_precheck_group'] = get_string('precheckingemptyset', 'qtype_coderunner');
+        }
 
+        if ($data['sandboxparams'] != '' &&
+                json_decode($data['sandboxparams']) === null) {
+            $errors['sandboxcontrols'] = get_string('badsandboxparams', 'qtype_coderunner');
+        }
 
-    /**
-     * Return a count of the number of test cases set as examples.
-     * @param array $data data from the form
-     */
-    private function num_examples($data) {
-        return isset($data['useasexample']) ? count($data['useasexample']) : 0;
-    }
+        list($templateerrors, $json) = $this->validate_template_params();
+        if (!$templateerrors) {
+            $this->formquestion->templateparamsevald = $json;
+        } else {
+            $errors['templateparams'] = $templateerrors;
+            $this->formquestion->templateparamsevald = '{}';
+        }
 
-    private function get_languages_and_types() {
-        // Return two arrays (language => language_upper_case) and (type => subtype) of
-        // all the coderunner question types available in the current course
-        // context.
-        // The subtype is the suffix of the type in the database,
-        // e.g. for java_method it is 'method'. The language is the bit before
-        // the underscore, and language_upper_case is a capitalised version,
-        // e.g. Java for java. For question types without a
-        // subtype the word 'Default' is used.
+        if ($data['prototypetype'] == 0 && ($data['grader'] !== 'TemplateGrader'
+                || $data['iscombinatortemplate'] === false)) {
+            // Unless it's a prototype or uses a combinator-template grader,
+            // it needs at least one testcase.
+            $testcaseerrors = $this->validate_test_cases($data);
+            $errors = array_merge($errors, $testcaseerrors);
+        }
 
-        $records = qtype_coderunner::get_all_prototypes();
-        $types = array();
-        foreach ($records as $row) {
-            if (($pos = strpos($row->coderunnertype, '_')) !== false) {
-                $subtype = substr($row->coderunnertype, $pos + 1);
-                $language = substr($row->coderunnertype, 0, $pos);
-            } else {
-                $subtype = 'Default';
-                $language = $row->coderunnertype;
-            }
-            $types[$row->coderunnertype] = $row->coderunnertype;
-            $languages[$language] = ucwords($language);
+        if ($data['iscombinatortemplate'] && empty($data['testsplitterre'])) {
+            $errors['templatecontrols'] = get_string('bad_empty_splitter', 'qtype_coderunner');
         }
-        asort($types);
-        asort($languages);
-        return array($languages, $types);
-    }
 
-    // Validate the test cases.
-    private function validate_test_cases($data) {
-        $errors = array(); // Return value.
-        $testcodes = $data['testcode'];
-        $stdins = $data['stdin'];
-        $expecteds = $data['expected'];
-        $marks = $data['mark'];
-        $count = 0;
-        $numnonemptytests = 0;
-        $num = max(count($testcodes), count($stdins), count($expecteds));
-        for ($i = 0; $i < $num; $i++) {
-            $testcode = trim($testcodes[$i]);
-            if ($testcode != '') {
-                $numnonemptytests++;
+        if ($data['prototypetype'] == 2 && ($data['saved_prototype_type'] != 2 ||
+                   $data['typename'] != $data['coderunnertype'])) {
+            // User-defined prototype, either newly created or undergoing a name change.
+            $typename = trim($data['typename']);
+            if ($typename === '') {
+                $errors['prototypecontrols'] = get_string('empty_new_prototype_name', 'qtype_coderunner');
+            } else if (!$this->is_valid_new_type($typename)) {
+                $errors['prototypecontrols'] = get_string('bad_new_prototype_name', 'qtype_coderunner');
             }
-            $stdin = trim($stdins[$i]);
-            $expected = trim($expecteds[$i]);
-            if ($testcode !== '' || $stdin != '' || $expected !== '') {
-                $count++;
-                $mark = trim($marks[$i]);
-                if ($mark != '') {
-                    if (!is_numeric($mark)) {
-                        $errors["testcode[$i]"] = get_string('nonnumericmark', 'qtype_coderunner');
-                    } else if (floatval($mark) <= 0) {
-                        $errors["testcode[$i]"] = get_string('negativeorzeromark', 'qtype_coderunner');
+        }
+
+        $penaltyregimeerror = $this->validate_penalty_regime($data);
+        if ($penaltyregimeerror) {
+             $errors['markinggroup'] = $penaltyregimeerror;
+        }
+
+        $resultcolumnsjson = trim($data['resultcolumns']);
+        if ($resultcolumnsjson !== '') {
+            $resultcolumns = json_decode($resultcolumnsjson);
+            if ($resultcolumns === null) {
+                $errors['resultcolumns'] = get_string('resultcolumnsnotjson', 'qtype_coderunner');
+            } else if (!is_array($resultcolumns)) {
+                $errors['resultcolumns'] = get_string('resultcolumnsnotlist', 'qtype_coderunner');
+            } else {
+                foreach ($resultcolumns as $col) {
+                    if (!is_array($col) || count($col) < 2) {
+                        $errors['resultcolumns'] = get_string('resultcolumnspecbad', 'qtype_coderunner');
+                        break;
+                    }
+                    foreach ($col as $el) {
+                        if (!is_string($el)) {
+                            $errors['resultcolumns'] = get_string('resultcolumnspecbad', 'qtype_coderunner');
+                            break;
+                        }
                     }
                 }
             }
         }
 
-        if ($count == 0) {
-            $errors["testcode[0]"] = get_string('atleastonetest', 'qtype_coderunner');
-        } else if ($numnonemptytests != 0 && $numnonemptytests != $count) {
-            $errors["testcode[0]"] = get_string('allornone', 'qtype_coderunner');
+        if ($data['attachments']) {
+            // Check a valid regular expression was given.
+            // Use '=' as the PCRE delimiter.
+            if (@preg_match('=^' . $data['filenamesregex'] . '$=', null) === false) {
+                $errors['filenamesgroup'] = get_string('badfilenamesregex', 'qtype_coderunner');
+            }
         }
+
+        if (count($errors) == 0) {
+            $errors = $this->validate_twigables();
+        }
+
+        if (count($errors) == 0 && !empty($data['validateonsave'])) {
+            $testresult = $this->validate_sample_answer($data);
+            if ($testresult) {
+                $errors['answer'] = $testresult;
+            }
+        }
+
+        $acelangs = trim($data['acelang']);
+        if ($acelangs !== '' && strpos($acelangs, ',') !== false) {
+            $parsedlangs = qtype_coderunner_util::extract_languages($acelangs);
+            if ($parsedlangs === false) {
+                $errors['languages'] = get_string('multipledefaults', 'qtype_coderunner');
+            } else if (count($parsedlangs[0]) === 0) {
+                $errors['languages'] = get_string('badacelangstring', 'qtype_coderunner');
+            }
+        }
+
+        // Don't allow the teacher to require more attachments than they allow; as this would
+        // create a condition that it's impossible for the student to meet.
+        if ($data['attachments'] != -1 && $data['attachments'] < $data['attachmentsrequired'] ) {
+            $errors['attachmentsrequired']  = get_string('mustrequirefewer', 'qtype_coderunner');
+        }
+
         return $errors;
     }
+    
 
-
-    // Check the templateparameters value, if given. Return an error message
-    // string, which will be empty if there are no errors.
+    // Check the templateparameters value, if given. Return an array containing
+    // the error message string, which will be empty if there are no errors, 
+    // and the JSON evaluated template parameters. 
     private function validate_template_params() {
         global $USER;
-        $templateparams = $this->question->templateparams;
+        $templateparams = $this->formquestion->templateparams;
         $errormessage = '';
-        $this->question->decodedparams = array();
-        if (!empty($templateparams)) {
-            $lang = $this->question->templateparamslang;
-            $seed = 0;
-            $json = $this->question->evaluate_template_params($templateparams, $lang, $seed);
-            $decoded = json_decode($json, true);
-            if ($decoded === null) {
-                 $errormessage = get_string('badtemplateparams', 'qtype_coderunner', $json);
-            }
+        $seed = mt_rand();
+        $json = $this->formquestion->evaluate_merged_parameters($seed); 
+        $decoded = json_decode($json, true);
+        if ($decoded === null) {
+             $errormessage = get_string('badtemplateparams', 'qtype_coderunner', $json);
         }
-        return $errormessage;
+        return array($errormessage, $json);
     }
     
     
- 
     private function validate_penalty_regime($data) {
         // Check the penalty regime and return an error string or an empty string if OK.
         $errorstring = '';
@@ -1031,9 +974,10 @@ private function validate_penalty_regime($data) {
     // form fields to error messages.
     private function validate_twigables() {
         $errors = array();
-        $question = $this->question;
-        $question->evaluate_merged_parameters(0);
-        $parameters = $question->parameters;
+        $question = $this->formquestion;
+        $jsonparams = $question->templateparamsevald;
+        $parameters = json_decode($jsonparams, true);
+        $parameters['QUESTION'] = $question;
 
         // Try twig expanding everything (see question::twig_all), with strict_variables true.
         foreach (['questiontext', 'answer', 'answerpreload', 'globalextra'] as $field) {
@@ -1042,7 +986,7 @@ private function validate_twigables() {
                 $text = $text['text'];
             }
             try {
-                $this->twig_render($text, $question->parameters, true);
+                $this->twig_render($text, $parameters, true);
             } catch (Twig_Error $ex) {
                 $errors[$field] = get_string('twigerror', 'qtype_coderunner',
                         $ex->getMessage());
@@ -1070,55 +1014,54 @@ private function validate_twigables() {
     }
 
 
-    // Render the given Twig text with the given params, using the global
-    // $USER variable (the question author) as a dummy student.
-    // @return Rendered text.
-    private function twig_render($text, $params=array(), $isstrict=false) {
-        global $USER;
-        $student = new qtype_coderunner_student($USER);
-        return qtype_coderunner_twig::render($text, $student, (array) $params, $isstrict);
-    }
-    
-
-    private function make_question_from_form_data($data) {
-        // Construct a question object containing all the fields from $data.
-        // Used in data pre-processing and when validating a question.
-        global $DB, $USER;
-        $question = new qtype_coderunner_question();
-        foreach ($data as $key => $value) {
-            if ($key === 'questiontext' || $key === 'generalfeedback') {
-                // Question text and general feedback are associative arrays.
-                $question->$key = $value['text'];
-            } else {
-                $question->$key = $value;
+    // Validate the test cases.
+    private function validate_test_cases($data) {
+        $errors = array(); // Return value.
+        $testcodes = $data['testcode'];
+        $stdins = $data['stdin'];
+        $expecteds = $data['expected'];
+        $marks = $data['mark'];
+        $count = 0;
+        $numnonemptytests = 0;
+        $num = max(count($testcodes), count($stdins), count($expecteds));
+        for ($i = 0; $i < $num; $i++) {
+            $testcode = trim($testcodes[$i]);
+            if ($testcode != '') {
+                $numnonemptytests++;
+            }
+            $stdin = trim($stdins[$i]);
+            $expected = trim($expecteds[$i]);
+            if ($testcode !== '' || $stdin != '' || $expected !== '') {
+                $count++;
+                $mark = trim($marks[$i]);
+                if ($mark != '') {
+                    if (!is_numeric($mark)) {
+                        $errors["testcode[$i]"] = get_string('nonnumericmark', 'qtype_coderunner');
+                    } else if (floatval($mark) <= 0) {
+                        $errors["testcode[$i]"] = get_string('negativeorzeromark', 'qtype_coderunner');
+                    }
+                }
             }
         }
-        $question->isnew = true;
-        $question->supportfilemanagerdraftid = $this->get_file_manager('datafiles');
-        $question->student =  new qtype_coderunner_student($USER);
 
-        // Clean the question object, get inherited fields and run the sample answer.
-        $qtype = new qtype_coderunner();
-        $qtype->clean_question_form($question, true);
-        $questiontype = $question->coderunnertype;
-        list($category) = explode(',', $question->category);
-        $contextid = $DB->get_field('question_categories', 'contextid', array('id' => $category));
-        $question->contextid = $contextid;
-        $context = context::instance_by_id($contextid, IGNORE_MISSING);
-        $question->prototype = $qtype->get_prototype($questiontype, $context);
-        $qtype->set_inherited_fields($question, $question->prototype);
-        return $question;
+        if ($count == 0) {
+            $errors["testcode[0]"] = get_string('atleastonetest', 'qtype_coderunner');
+        } else if ($numnonemptytests != 0 && $numnonemptytests != $count) {
+            $errors["testcode[0]"] = get_string('allornone', 'qtype_coderunner');
+        }
+        return $errors;
     }
 
+
     // Check the sample answer (if there is one)
     // Return an empty string if there is no sample answer and no attachments,
     // or if the sample answer passes all the tests.
     // Otherwise return a suitable error message for display in the form.
     private function validate_sample_answer() {
-        assert(!empty($this->question->parameters));
+        assert(!empty($this->formquestion->parameters));
         $attachmentssaver = $this->get_sample_answer_file_saver();
         $files = $attachmentssaver ? $attachmentssaver->get_files() : array();
-        $answer = $this->question->answer;
+        $answer = $this->formquestion->answer;
         if (trim($answer) === '' && count($files) == 0) {
             return ''; // Empty answer and no attachments.
         }
@@ -1126,32 +1069,35 @@ private function validate_sample_answer() {
         // what language to use. If there is a specific answer_language template
         // parameter, that is used. Otherwise the default language (if specified)
         // or the first in the list is used.
-        $acelang = trim($this->question->acelang);
+        $acelang = trim($this->formquestion->acelang);
         if ($acelang !== '' && strpos($acelang, ',') !== false) {
-            if (empty($this->question->parameters['answer_language'])) {
+            if (empty($this->formquestion->parameters['answer_language'])) {
                 list($languages, $answerlang) = qtype_coderunner_util::extract_languages($acelang);
                 if ($answerlang === '') {
                     $answerlang = $languages[0];
                 }
             } else {
-                $answerlang = $this->question->parameters['answer_language'];
+                $answerlang = $this->formquestion->parameters['answer_language'];
             }
         }
 
         try {
-            $this->question->start_attempt();
-            $response = array('answer' => $this->question->answer);
+            $savedevalpertry = $this->formquestion->templateparamsevalpertry;
+            $this->formquestion->templateparamsevalpertry = 0; // Save an extra evaluation
+            $this->formquestion->start_attempt();
+            $this->formquestion->templateparamsevalpertry = $savedevalpertry;
+            $response = array('answer' => $this->formquestion->answer);
             if (!empty($answerlang)) {
                 $response['language'] = $answerlang;
             }
             if ($attachmentssaver) {
                 $response['attachments'] = $attachmentssaver;
             }
-            $error = $this->question->validate_response($response);
+            $error = $this->formquestion->validate_response($response);
             if ($error) {
                 return $error;
             }
-            list($mark, $state, $cachedata) = $this->question->grade_response($response);
+            list($mark, $state, $cachedata) = $this->formquestion->grade_response($response);
         } catch (Exception $e) {
             return $e->getMessage();
         }
@@ -1166,6 +1112,107 @@ private function validate_sample_answer() {
         }
     }
 
+    // UTILITY FUNCTIONS.
+    // =================.
+
+    // True iff the given name is valid for a new type, i.e., it's not in use
+    // in the current context (Currently only a single global context is
+    // implemented).
+    private function is_valid_new_type($typename) {
+        list($langs, $types) = $this->get_languages_and_types();
+        return !array_key_exists($typename, $types);
+    }
+
+
+    /**
+     * Return a count of the number of test cases set as examples.
+     * @param array $data data from the form
+     */
+    private function num_examples($data) {
+        return isset($data['useasexample']) ? count($data['useasexample']) : 0;
+    }
+
+    private function get_languages_and_types() {
+        // Return two arrays (language => language_upper_case) and (type => subtype) of
+        // all the coderunner question types available in the current course
+        // context.
+        // The subtype is the suffix of the type in the database,
+        // e.g. for java_method it is 'method'. The language is the bit before
+        // the underscore, and language_upper_case is a capitalised version,
+        // e.g. Java for java. For question types without a
+        // subtype the word 'Default' is used.
+
+        $records = qtype_coderunner::get_all_prototypes();
+        $types = array();
+        foreach ($records as $row) {
+            if (($pos = strpos($row->coderunnertype, '_')) !== false) {
+                $subtype = substr($row->coderunnertype, $pos + 1);
+                $language = substr($row->coderunnertype, 0, $pos);
+            } else {
+                $subtype = 'Default';
+                $language = $row->coderunnertype;
+            }
+            $types[$row->coderunnertype] = $row->coderunnertype;
+            $languages[$language] = ucwords($language);
+        }
+        asort($types);
+        asort($languages);
+        return array($languages, $types);
+    }
+    
+    // Render the given Twig text with the given params, using the global
+    // $USER variable (the question author) as a dummy student.
+    // @return Rendered text.
+    private function twig_render($text, $params=array(), $isstrict=false) {
+        global $USER;
+        $student = new qtype_coderunner_student($USER);
+        return qtype_coderunner_twig::render($text, $student, (array) $params, $isstrict);
+    }
+    
+
+    private function make_question_from_form_data($data) {
+        // Construct a question object containing all the fields from $data.
+        // Used in data pre-processing and when validating a question.
+        global $DB, $USER;
+        $question = new qtype_coderunner_question();
+        foreach ($data as $key => $value) {
+            if ($key === 'questiontext' || $key === 'generalfeedback') {
+                // Question text and general feedback are associative arrays.
+                $question->$key = $value['text'];
+            } else {
+                $question->$key = $value;
+            }
+        }
+        $question->isnew = true;
+        $question->supportfilemanagerdraftid = $this->get_file_manager('datafiles');
+        $question->student =  new qtype_coderunner_student($USER);
+
+        // Clean the question object, get inherited fields and run the sample answer.
+        $qtype = new qtype_coderunner();
+        $qtype->clean_question_form($question, true);
+        $questiontype = $question->coderunnertype;
+        list($category) = explode(',', $question->category);
+        $contextid = $DB->get_field('question_categories', 'contextid', array('id' => $category));
+        $question->contextid = $contextid;
+        $context = context::instance_by_id($contextid, IGNORE_MISSING);
+        $question->prototype = $qtype->get_prototype($questiontype, $context);
+        $qtype->set_inherited_fields($question, $question->prototype);
+        return $question;
+    }
+
+    
+   
+    // Stop gap function until UI parameters properly refactored.
+    // Returns the Json for the merged template parameters. Only works
+    // once the question has been saved. 
+    private function get_merged_params() {
+        if (isset($this->question->options->templateparamsevald)) {
+            return $this->question->options->templateparamsevald;
+        } else {
+            return '{}';
+        }
+    }
+
 
     // Return a file saver for the sample answer filemanager, if present.
     private function get_sample_answer_file_saver() {
diff --git a/lang/en/qtype_coderunner.php b/lang/en/qtype_coderunner.php
index e96b2e6f2..d3798be04 100644
--- a/lang/en/qtype_coderunner.php
+++ b/lang/en/qtype_coderunner.php
@@ -1059,18 +1059,27 @@ function should be applied, e.g. <code>{{STUDENT_ANSWER | e(\'py\')}}</code> is
 If the template-debugging checkbox is clicked, the program generated
 for each testcase will be displayed in the output.';
 $string['templateparams'] = 'Template params';
+$string['templateparamsevalpertry'] = 'Evaluate on each attempt';
 $string['templateparamslang'] = 'Preprocessor';
-$string['templateparams_help'] = 'The template parameters field lets you pass string parameters to a question\'s
-template(s). If non-blank, this must evaluate to a JSON-format record. It can
-be a pure JSON string, or JSON with embedded Twig code or a Python
-program that outputs JSON when run. The latter mode is highly experimental
-and may have significant performance implications because the template
-parameter code must
-be sent to the Jobe sandbox to be executed even before the question can be
-displayed. To enable the Python mode, set the preprocessor to <em>Python</em>.
+$string['templateparams_help'] = 'If non-blank, the template parameters field must
+evaluate to a JSON-format record. In its simplest form the field is just a JSON
+record defining a set of variables that are added to the environment for the Twig
+template engine when it expands the template. If a preprocessor is specified,
+the template parameters are first processed by the specified language
+to yield a JSON record. See the documentation for details.
+
+<b>Warning:<b> use of a preprocessor other than Twig can have drastic performance
+implications if the Evaluate-on-each-attempt checkbox is
+checked, which it has to be if used for randomisation or for per-student question
+customisation. Preprocessing must be done before a question
+can be displayed to a student and, except for Twig, takes place on the Jobe sandbox
+server. Every attempt on every question of this sort by every student will result in a job
+being sent to that server. This can result in thousands of jobs hitting the
+Jobe server at once at the start of a large test or exam, which will almost
+certainly overload it. Caveat Emptor!
 
 It <em>Hoist template parameters</em> is unchecked the fields of
-the JSON record can then be used within the template in the form
+the JSON record can be used within the template in the form
 QUESTION.parameters.&lt;&lt;param&gt;&gt; For example, if template params is
 
         {"age": 23}
@@ -1079,30 +1088,7 @@ function should be applied, e.g. <code>{{STUDENT_ANSWER | e(\'py\')}}</code> is
 template variable <code>{{ QUESTION.parameters.age }}</code>.
 
 If <em>Hoist template parameters</em> is checked the json field names can be
-used without the prefix, e.g. as <code>{{ age }}</code> directly.
-
-The set of template parameters passed to the template consists of any template
-parameters defined in the prototype with the question template parameters
-merged in. Question parameters can thus override prototype parameters, but not
-delete them.
-
-Template parameters can also be used to provide randomisation within a question.
-When the question is first instantiated the template parameters are passed
-either through the Twig template engine if the Preprocessor is <em>Twig</em>
-or the Python interpreter otherwise to yield the final JSON version.
-Twig\'s "random" function can
-be used to assign random values to template parameters. If the "Twig All" checkbox
-is checked, all other fields of the question (question text, answer, test cases
-etc) are the also processed by Twig, with the template parameters as an
-environment. This can result in different
-students seeing different random variants of the question. See the documentation
-for details.
-
-If Python is the preprocessor the template parameters must be a Python
-program that can accept through sys.argv up to two arguments of the form
-<em>--seed=1234</em> and <em>--student=\<json-encode-student-record\></em> where
-<em>seed</em> is the random number seed and <em>student</em> is the current
-student.';
+used without the prefix, e.g. as <code>{{ age }}</code> directly.';
 $string['testalltitle'] = 'Test all questions in this context';
 $string['testallincategory'] = 'Test all questions in this category';
 $string['testcase'] = 'Test case {$a}';
diff --git a/question.php b/question.php
index 7b449d05f..549727a56 100644
--- a/question.php
+++ b/question.php
@@ -64,7 +64,7 @@ public function start_attempt(question_attempt_step $step=null, $variant=null) {
             $this->student = $DB->get_record('user', array('id' => $userid));
             $step->set_qt_var('_STUDENT', serialize($this->student));
         } else {  // Validation, so just use the global $USER as student.
-            $this->student = $USER;
+            $this->student = new qtype_coderunner_student($USER);
         }
 
         $seed = mt_rand();
@@ -103,7 +103,8 @@ public function apply_attempt_state(question_attempt_step $step) {
     //
     public function evaluate_question_for_display($seed, $step) {
         $this->get_prototype();
-        $this->evaluate_merged_parameters($seed, $step);
+        $paramsjson = $this->evaluate_merged_parameters($seed, $step);
+        $this->parameters = json_decode($paramsjson);
         if ($this->twigall) {
             $this->twig_all();
         }        
@@ -116,28 +117,41 @@ public function evaluate_question_for_display($seed, $step) {
      * or the student. 
      * The parameters are defined by running the template parameters field
      * through the appropriate language processor as specified by the
-     * templateparamslang field (default: Twig) and then json-decoding
-     * the result to a PHP associative array. That array needs to be merged with
+     * templateparamslang field (default: Twig). The result needs to be merged with
      * the prototype's parameters, which are subject to the same process.
-     * After running this function, the $this->parameters is the array of
-     * parameters.
+     * After running this function, the $this->parameters is a stdClass object
+     * with all the parameters as attributes.
+     * If the prototype is missing, process just the template parameters from
+     * this question; an error message will be given later.
      * @param int $seed The random number seed to set for Twig randomisation
      * @param question_attempt_step $step The current question attempt step
+     * @return string the json string of the merged template parameters.
      */
   
      function evaluate_merged_parameters($seed, $step=null) {
-        assert(isset($this->templateparams));
-        $paramsjson = $this->template_params_json($this->templateparams, 
-                    $this->templateparamslang, $seed, $step, '_template_params');
-        $prototype = $this->prototype;
-        $prototypeparamsjson = $this->template_params_json($prototype->templateparams,
-                $prototype->templateparamslang, $seed, $step, '_prototype__template_params');
-   
-        $mergedjson = qtype_coderunner_util::merge_json($prototypeparamsjson, $paramsjson);
-        if (empty($mergedjson)) {
-            $mergedjson = '{}';
-        }
-        $this->parameters = json_decode($mergedjson);
+        // If we have a value for templateparamsevald and we're asked to use it, do so.
+        if (!$this->templateparamsevalpertry && !empty($this->templateparamsevald)) {
+            $paramsjson = $this->templateparamsevald;
+        } else {
+         
+            // Otherwise we have to evaluate this and our prototypes template
+            // parameters and merge them.
+            assert(isset($this->templateparams));
+            $paramsjson = $this->template_params_json($this->templateparams, 
+                        $this->templateparamslang, $seed, $step, '_template_params');
+            $prototype = $this->prototype;
+            if ($prototype !== null) {
+                // Merge with prototype parameters (unless prototype is missing).
+                $prototypeparamsjson = $this->template_params_json($prototype->templateparams,
+                    $prototype->templateparamslang, $seed, $step, '_prototype__template_params');
+                $paramsjson = qtype_coderunner_util::merge_json($prototypeparamsjson, $paramsjson);
+            }
+       
+            if (empty($paramsjson)) {
+                $paramsjson = '{}';
+            }
+        }
+        return $paramsjson;
 
         // TODO - how to report an error on the json_decode??
     }
@@ -154,7 +168,7 @@ function evaluate_merged_parameters($seed, $step=null) {
      * json (with suffix '_json').
      * @return string THe Json template parameters.
      */
-    private function template_params_json($params, $lang, $seed, $step, $qtvar) {
+    function template_params_json($params, $lang, $seed=0, $step=null, $qtvar='') {
         if ($step === null) {
             $jsontemplateparams = $this->evaluate_template_params($params,
                     $lang, $seed, $this->student);
@@ -186,25 +200,28 @@ private function template_params_json($params, $lang, $seed, $step, $qtvar) {
      * valid json).
      */
     function evaluate_template_params($templateparams, $lang, $seed) {
-        if ($lang == 'twig') {
+        if ($lang == 'None') {
+            $jsontemplateparams = $templateparams;
+        } else if ($lang == 'twig') {
             $jsontemplateparams = $this->twig_render_with_seed($templateparams, $seed);
+        } else if (!$this->templateparamsevalpertry && !empty($this->templateparamsevald)) {
+            $jsontemplateparams = $this->templateparamsevald;
         } else {
-            assert($lang == 'python');
-            $jsontemplateparams = $this->evaluate_template_params_python($templateparams, $seed);
+            $jsontemplateparams = $this->evaluate_template_params_on_jobe($templateparams, $lang, $seed);
         }
         return $jsontemplateparams;
     }
     
     
     /**
-     * Evaluate a template parameter string using Python in the Jobe
-     * engine. Return value should be the JSON template parameter string.
+     * Evaluate a template parameter string using a given language on the Jobe
+     * server. Return value should be the JSON template parameter string.
      *
      * @param string $templateparams The template parameters to evaluate.
      * @param int $seed The random number seed to use when evaluating.
      * @return string The output from the run.
      */
-    private function evaluate_template_params_python($templateparams, $seed) {
+    private function evaluate_template_params_on_jobe($templateparams, $lang, $seed) {
         $files = array();
         $input = '';
         $runargs = array("seed=$seed");
@@ -213,7 +230,7 @@ private function evaluate_template_params_python($templateparams, $seed) {
         }
         $sandboxparams = array("runargs" => $runargs);
         $sandbox = $this->get_sandbox();
-        $run = $sandbox->execute($templateparams, "python3", $input, $files, $sandboxparams);
+        $run = $sandbox->execute($templateparams, $lang, $input, $files, $sandboxparams);
         if ($run->error !== qtype_coderunner_sandbox::OK) {
             return qtype_coderunner_sandbox::error_string($run);
         } else if ($run->result != qtype_coderunner_sandbox::RESULT_SUCCESS) {
@@ -226,7 +243,7 @@ private function evaluate_template_params_python($templateparams, $seed) {
     
     // Render the given twig text using the given random number seed and
     // student variable. This version should be called only during question
-    // initialisation when randomisation is being done.
+    // initialisation when evaluating the template parameters.
     private function twig_render_with_seed($text, $seed) {
         mt_srand($seed);
         return qtype_coderunner_twig::render($text, $this->student);
diff --git a/questiontype.php b/questiontype.php
index 597195822..78b98b41f 100644
--- a/questiontype.php
+++ b/questiontype.php
@@ -110,6 +110,8 @@ public function extra_question_fields() {
             'templateparams',
             'hoisttemplateparams',
             'templateparamslang',
+            'templateparamsevalpertry',
+            'templateparamsevald',
             'twigall',
             'uiplugin',
             'attachments',
@@ -143,6 +145,8 @@ public static function noninherited_fields() {
             'templateparams',
             'hoisttemplateparams',
             'templateparamslang',
+            'templateparamsevalpertry',
+            'templateparamsevald',
             'twigall',
             'attachments',
             'attachmentsrequired',
@@ -383,11 +387,6 @@ public function move_files($questionid, $oldcontextid, $newcontextid) {
     // The various fields are initialised from the prototype, then overridden
     // by any non-null values in the specific question.
     //
-    // As a special case, required by edit_coderunner_form, an option
-    // 'mergedtemplateparams' is set by merging the prototype question's
-    // template parameters with the given question's template parameters,
-    // with the caveat that template parameters with embedded twig code that
-    // aren't valid JSON are ignored.
     public function get_question_options($question) {
         global $CFG, $DB, $OUTPUT;
         parent::get_question_options($question);
@@ -395,18 +394,11 @@ public function get_question_options($question) {
         if ($options->prototypetype != 0) { // Question prototype?
             // Yes. It's 100% customised with nothing to inherit.
             $options->customise = true;
-            $options->mergedtemplateparams = $options->templateparams;
         } else {
             $qtype = $options->coderunnertype;
             $context = $this->question_context($question);
             $prototype = $this->get_prototype($qtype, $context);
             $this->set_inherited_fields($options, $prototype);
-            if ($prototype !== null && trim($prototype->templateparams) !== '') {
-                $options->mergedtemplateparams = qtype_coderunner_util::merge_json(
-                    $prototype->templateparams, $options->templateparams);
-            } else { // Missing prototype!
-                $options->mergedtemplateparams = $options->templateparams;
-            }
         }
 
         // Add in any testcases.
@@ -453,10 +445,6 @@ public function set_inherited_fields($target, $prototype) {
             }
         }
 
-        // Save prototype template params in the target, to be merged with
-        // the question template params if the target is actually run.
-        $target->prototypetemplateparams = $prototype->templateparams;
-
         if (!isset($target->sandbox)) {
             $target->sandbox = null;
         }
@@ -744,6 +732,8 @@ public function
             'iscombinatortemplate' => null,  // Probably unnecessary?
             'template' => null,  // Probably unnecessary?
             'templateparamslang' => 'twig',
+            'templateparamsevalpertry' => 0,
+            'templateparamsevald' => null,
             'attachments' => 0
         );
 
diff --git a/tests/behat/check_python_template_params.feature b/tests/behat/check_python_template_params.feature
index 48815cbf7..7e38507f8 100644
--- a/tests/behat/check_python_template_params.feature
+++ b/tests/behat/check_python_template_params.feature
@@ -1,7 +1,7 @@
 
 @qtype @qtype_coderunner @javascript @pythonpreprocessortest
-Feature: Check that Python can be used instead of Twig as a template params preprocessor and that it processes the STUDENT variable correctly.
-  To check that the STUDENT template parameter variables work when python is the preprocessor
+Feature: Check that Python and other languages can be used instead of Twig as a template params preprocessor and that they processes the STUDENT variable correctly.
+  To check that the STUDENT template parameter variables work when a language other than python is the preprocessor
   As a teacher
   I should be able to write a function that prints the seed and my username it should be marked right
 
@@ -29,14 +29,15 @@ Background:
     And I disable UI plugins
     And I add a "CodeRunner" question filling the form with:
       | id_coderunnertype       | python3                                    |
-      | id_customise            | 1                                         |
+      | id_customise            | 1                                          |
       | id_name                 | STUDENT variable                           |
       | id_questiontext         | Write a program that prints True if seed parameter provided, then {{ username }}  |
       | id_answerboxlines       | 5                                          |
       | id_validateonsave       | 0                                          |
       | id_templateparams       | import sys, json; keyvalues = {param.split('=')[0]: param.split('=')[1] for param in sys.argv[1:]}; print(json.dumps(keyvalues)) |
-      | id_templateparamslang   | python                                     |
-      | id_template             | print(int("{{seed}}") > 0, "{{username}}")    |
+      | id_templateparamslang   | python3                                    |
+      | id_templateparamsevalpertry | 1                                      |
+      | id_template             | print(int("{{seed}}") > 0, end=' ');  {{STUDENT_ANSWER}} |
       | id_answer               | # Unused                                   |
       | id_iscombinatortemplate | 0                                          |
       | id_testcode_0           | # Unused                                   |
@@ -75,3 +76,33 @@ Background:
     Then I should see "Write a program that prints True if seed parameter provided, then student1"
     And I should see "Passed all tests"
 
+  Scenario: Turn off per-try evaluation. Question should fail when attempted by student. 
+
+    When I choose "Edit question" action for "STUDENT variable" in the question bank
+    And I set the following fields to these values:
+      | id_templateparamsevalpertry | 0 |
+      | id_questiontext             | Variant without per-try evaluation  |
+    And I press "id_submitbutton"
+    Then I should see "Created by"
+    And I should see "Last modified by"
+
+    When I am on "Course 1" course homepage
+    And I follow "Test quiz"
+    And I press "Preview quiz now"
+    Then I should see "Variant without per-try evaluation"
+
+    When I set the field with xpath "//textarea[contains(@name, 'answer')]" to "print('teacher1')"
+    And I press "Check"
+    Then I should see "Passed all tests"
+
+    When I log out
+    And I log in as "student1"
+    And I am on "Course 1" course homepage
+    And I follow "Test quiz"
+    And I press "Attempt quiz"
+    Then I should see "Variant without per-try evaluation"
+    And I set the field with xpath "//textarea[contains(@name, 'answer')]" to "print('student1')"
+    And I press "Check"
+    Then I should see "True student1"
+    And I should see "True teacher1"
+    And I should not see "Passed all tests"
diff --git a/tests/helper.php b/tests/helper.php
index 76d4b9b8a..592ba0feb 100644
--- a/tests/helper.php
+++ b/tests/helper.php
@@ -142,6 +142,8 @@ public function get_coderunner_question_form_data_sqr() {
         $form->templateparams = "";
         $form->hoisttemplateparams = 1;
         $form->templateparamslang = 'twig';
+        $form->templateparamsevalpertry = 0;
+        $form->templateparamsevald = null;
         $form->twigall = 0;
         $form->prototypetype = 0;
         $form->sandbox = 'DEFAULT';
@@ -198,6 +200,8 @@ public function get_coderunner_question_form_data_printans() {
         $form->templateparams = "";
         $form->hoisttemplateparams = 1;
         $form->templateparamslang = 'twig';
+        $form->templateparamsevalpertry = 0;
+        $form->templateparamsevald = null;
         $form->twigall = 0;
         $form->prototypetype = 0;
         $form->sandbox = 'DEFAULT';
@@ -1176,6 +1180,8 @@ private function make_coderunner_question($type, $name = '', $questiontext = '',
         $coderunner->coderunnertype = $type;
         $coderunner->templateparams = '';
         $coderunner->templateparamslang = 'twig';
+        $coderunner->templateparamsevalpertry = 0;
+        $coderunner->templateparamsevald = null;
         $coderunner->hoisttemplateparams = 0;
         $coderunner->twigall = 0;
         $coderunner->prototypetype = 0;
diff --git a/tests/prototype_test.php b/tests/prototype_test.php
index b4a6ac6f5..9f8d7758a 100644
--- a/tests/prototype_test.php
+++ b/tests/prototype_test.php
@@ -138,6 +138,8 @@ public function test_export() {
     <sandboxparams></sandboxparams>
     <templateparams><![CDATA[{"xxx":1, "zzz":2}]]></templateparams>
     <templateparamslang>twig</templateparamslang>
+    <templateparamsevalpertry>0</templateparamsevalpertry>
+    <templateparamsevald>twig</templateparamsevald>
     <hoisttemplateparams>0</hoisttemplateparams>
     <twigall>0</twigall>
     <uiplugin></uiplugin>
diff --git a/tests/walkthrough_randomised_questions.php b/tests/walkthrough_randomised_questions.php
index 08ee7389f..607aedea0 100644
--- a/tests/walkthrough_randomised_questions.php
+++ b/tests/walkthrough_randomised_questions.php
@@ -129,6 +129,8 @@ private function add_fields($q, $seed=false) {
 
         $q->templateparams = $seeding . $templateparams;
         $q->templateparamslang = 'twig';
+        $q->templateparamsevalpertry = 0;
+        $q->templateparamsevald = null;
         $q->hoisttemplateparams = 1;
         $q->twigall = 1;
         $q->questiontext = 'Write a function {{ func }}';
diff --git a/version.php b/version.php
index ff19b4a2e..16c80f9e2 100644
--- a/version.php
+++ b/version.php
@@ -22,7 +22,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version  = 2020120702;
+$plugin->version  = 2020121501;
 $plugin->requires = 2015051200;
 $plugin->cron = 0;
 $plugin->component = 'qtype_coderunner';