New feature enabling some specific outcome variables to remain

preserved at outcome processing time.

composer.json

@@ -2,7 +2,7 @@
 	"name": "qtism/qtism",
 	"description": "OAT QTI Software Module Library",
 	"type": "library",
-	"version": "0.9.8",
+	"version": "0.9.9",
 	"authors": [
 		{
 			"name": "Open Assessment Technologies S.A.",

qtism/runtime/common/State.php

@@ -158,16 +158,17 @@ public function offsetGet($offset) {
 	 * Reset all test-level outcome variables to their defaults.
 	 * 
 	 * @param boolean $preserveBuiltIn Whether the built-in outcome variable 'completionStatus'.
+	 * @param array $preserve An array of identifiers reflecting variables that must not be reset but preserved.
 	 */
-	public function resetOutcomeVariables($preserveBuiltIn = true) {
+	public function resetOutcomeVariables($preserveBuiltIn = true, array $preserve = array()) {
 	    $data = &$this->getDataPlaceHolder();
 
 	    foreach (array_keys($data) as $k) {
 	        if ($data[$k] instanceof OutcomeVariable) {
 	        	if ($preserveBuiltIn === true && $k === 'completionStatus') {
 	        		continue;
 	        	}
-	        	else {
+	        	else if (in_array($k, $preserve) === false) {
 	        		$data[$k]->applyDefaultValue();	
 	        	}
 	        }

qtism/runtime/tests/AssessmentTestSession.php

@@ -149,6 +149,13 @@ class AssessmentTestSession extends State {
 	 */
 	private $sessionManager;
 
+	/**
+	 * An array of identifiers representing outcome variable that must not be applied their default value at outcome processing time.
+	 * 
+	 * @var array
+	 */
+	private $preservedOutcomeVariables;
+
 	/**
 	 * Create a new AssessmentTestSession object.
 	 *
@@ -167,6 +174,7 @@ public function __construct(AssessmentTest $assessmentTest, AbstractSessionManag
 		$this->setPendingResponseStore(new PendingResponseStore());
 		$durationStore = new DurationStore();
 		$this->setDurationStore($durationStore);
+		$this->setPreservedOutcomeVariables(array());
 
 		// Take the outcomeDeclaration objects of the global scope.
 		// Instantiate them with their defaults.
@@ -414,6 +422,24 @@ public function setSessionManager(AbstractSessionManager $sessionManager) {
 	public function getSessionManager() {
 	    return $this->sessionManager;
 	}
+
+	/**
+	 * Set the identifiers of the outcome variables that must not be applied their default value at outcome processing time.
+	 * 
+	 * @param array $identifiers
+	 */
+	public function setPreservedOutcomeVariables(array $identifiers) {
+	    $this->preservedOutcomeVariables = $identifiers;
+	}
+
+	/**
+	 * Get the identifiers of the outcome variables that must not be applied their default value at outcome processing time.
+	 * 
+	 * @return array
+	 */
+	public function getPreservedOutcomeVariables() {
+	    return $this->preservedOutcomeVariables;
+	}
 
 	/**
 	 * Get a weight by using a prefixed identifier e.g. 'Q01.weight1'
@@ -1718,7 +1744,7 @@ protected function outcomeProcessing() {
 	        // As per QTI Spec:
 	        // The values of the test's outcome variables are always reset to their defaults prior
 	        // to carrying out the instructions described by the outcomeRules.
-	        $this->resetOutcomeVariables();
+	        $this->resetOutcomeVariables(true, $this->getPreservedOutcomeVariables());
 
 	        $outcomeProcessing = $this->getAssessmentTest()->getOutcomeProcessing();
 

test/qtism/runtime/tests/AssessmentTestSessionTest.php

@@ -1409,4 +1409,37 @@ public function testEmptySection() {
 	    // and the session is then closed.
 	    $this->assertEquals(AssessmentTestSessionState::CLOSED, $session->getState());
 	}
+
+	public function testPreserveOutcomes() {
+	    // Aims at testing that even a section of the test is empty,
+	    // it is simply ignored at runtime.
+	    $doc = new XmlCompactDocument();
+	    $doc->load(self::samplesDir() . 'custom/runtime/preserve_test_outcomes.xml');
+	    $manager = new SessionManager();
+
+	    $session = $manager->createAssessmentTestSession($doc->getDocumentComponent());
+	    $session->setPreservedOutcomeVariables(array('PRESERVED'));
+	    $session->beginTestSession();
+
+	    $this->assertEquals('I will be preserved!', $session['PRESERVED']->getValue());
+	    $session['PRESERVED'] = new String('I am still preserved!');
+
+	    $this->assertEquals(0, $session['NOTPRESERVED']->getValue());
+
+	    $this->assertEquals('Q01', $session->getCurrentAssessmentItemRef()->getIdentifier());
+	    $session->beginAttempt();
+	    $session->endAttempt(new State(array(new ResponseVariable('RESPONSE', BaseType::IDENTIFIER, Cardinality::SINGLE, new Identifier('ChoiceA')))));
+	    $session->moveNext();
+
+	    $this->assertEquals('I am still preserved!', $session['PRESERVED']->getValue());
+	    $this->assertEquals(1, $session['NOTPRESERVED']->getValue());
+
+	    $this->assertEquals('Q02', $session->getCurrentAssessmentItemRef()->getIdentifier());
+	    $session->beginAttempt();
+	    $session->endAttempt(new State(array(new ResponseVariable('RESPONSE', BaseType::IDENTIFIER, Cardinality::SINGLE, new Identifier('ChoiceB')))));
+	    $session->moveNext();
+
+	    $this->assertEquals('I am still preserved!', $session['PRESERVED']->getValue());
+	    $this->assertEquals(1, $session['NOTPRESERVED']->getValue());
+	}
 }