qtype_stack now depends on and uses qbehaviour_dfexplicitvaildate.

doc/en/Installation/index.md

@@ -15,7 +15,14 @@ Maxima can be [downloaded](http://maxima.sourceforge.net/download.html) as a sel
 installer program for Windows, RPMs for Linux or as source for all platforms.  Maxima and
 GNUPlot will install themselves in suitable directories.
 
-## 3. Add the STACK question type
+## 3. Add the Deferred feedback with explicit validation question behaviour question behaviour
+
+STACK uses this question behaviour.
+
+1. Obtain the code. Either [download the zip file](https://github.com/timhunt/moodle-qbehaviour_dfexplicitvaildate/zipball/master), unzip it, and place it in the directory `moodle\question\behaviour\dfexplicitvaildate`. (You will need to rename the directory `moodle-qbehaviour_dfexplicitvaildate -> dfexplicitvaildate`.) Alternatively, get the code using git by running the following command in the top level folder of your Moodle install: `git clone git://github.com/timhunt/moodle-qbehaviour_dfexplicitvaildate.git question/behaviour/dfexplicitvaildate`.
+2. Login to Moodle as the admin user and click on Notifications in the Site Administration panel.
+
+## 4. Add the STACK question type
 
 STACK is a question type for the moodle quiz.
 
@@ -28,7 +35,7 @@ You must be able to connect to the CAS, and for the CAS to successfully create p
 
 You should now have a question type available to the moodle quiz.
 
-## 4. Add the STACK question format
+## 5. Add the STACK question format
 
 If you wish to import STACK 2 questions into STACK 3 you will need to install the STACK question format separately.  This is distributed as `qformat_stack`.  It provides a different _question format_ for the Moodle quiz importer.
 

question.php

@@ -161,6 +161,27 @@ class qtype_stack_question extends question_graded_automatically {
         $this->prtresults = array();
     }
 
+    /**
+     * @return bool do any of the inputs in this question require the student
+     *      validat the input.
+     */
+    protected function any_inputs_require_validation() {
+        foreach ($this->inputs as $name => $input) {
+            if ($input->requires_validation()) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public function make_behaviour(question_attempt $qa, $preferredbehaviour) {
+        if ($preferredbehaviour == 'deferredfeedback' && $this->any_inputs_require_validation()) {
+            return question_engine::make_behaviour('dfexplicitvaildate', $qa, $preferredbehaviour);
+        }
+
+        return parent::make_behaviour($qa, $preferredbehaviour);
+    }
+
     public function start_attempt(question_attempt_step $step, $variant) {
 
         // Work out the right seed to use.

version.php

@@ -24,9 +24,12 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version  = 2012043001;
+$plugin->version   = 2012051600;
 $plugin->requires  = 2012020200;
 $plugin->cron      = 0;
-
 $plugin->component = 'qtype_stack';
 $plugin->maturity  = MATURITY_ALPHA;
+
+$plugin->dependencies = array(
+    'qbehaviour_dfexplicitvaildate' => 2012051600
+);