Added AbstractStorage::exists() and AbstractStorage::delete().

README.md

@@ -11,7 +11,7 @@
 An IMS QTI (Question & Test Interoperability) Software Development Kit for PHP 5.3 and higher supporting a wide 
 range of features described by the [IMS QTI specification family](http://www.imsglobal.org/question).
 
-__This implementation of QTI is under constant enhancement. The API of the master branch might change at any time. See release 2.0.0 for the last stable version.__
+__This implementation of QTI is under constant enhancement. The API of the master branch might change at any time. See release 3.x.x. for the last stable version.__
 
 ## Features
 
@@ -26,7 +26,7 @@ __This implementation of QTI is under constant enhancement. The API of the maste
 * Nice and Clean API for QTI Document manipulation/traversal
 * PreConditions and Branching
 * Response/Outcome Processing
-* Unit Testing Driven from PHP 5.3 to 5.6
+* Unit Testing Driven from PHP 5.3 to 7.0
 
 ## Installation (developers)
 

src/qtism/runtime/storage/binary/TemporaryQtiBinaryStorage.php

@@ -77,7 +77,7 @@ protected function getRetrievalStream($sessionId)
         $read = @file_get_contents($path);
 
         if ($read === false || strlen($read) === 0) {
-            $msg = "An error occured while retrieving the binary stream at '${path}'.";
+            $msg = "An error occured while retrieving the binary stream at '${path}'. Nothing could be read. The file is empty or missing.";
             throw new RuntimeException($msg);
         }
 
@@ -91,4 +91,21 @@ protected function createBinaryStreamAccess(IStream $stream)
     {
         return new QtiBinaryStreamAccess($stream, new FileSystemFileManager());
     }
+
+    /**
+     * @see \qtism\runtime\storage\binary\AbstractStorage::exists()
+     */
+    public function exists($sessionId)
+    {
+        $path = sys_get_temp_dir() . DIRECTORY_SEPARATOR . md5($sessionId) . '.bin';
+        return @is_readable($path);
+    }
+
+    /**
+     * @see \qtism\runtime\storage\binary\AbstractStorage::delete()
+     */
+    public function delete($sessionId)
+    {
+        return @unlink(sys_get_temp_dir() . DIRECTORY_SEPARATOR . md5($sessionId) . '.bin');
+    }
 }

src/qtism/runtime/storage/common/AbstractStorage.php

@@ -89,6 +89,9 @@ protected function getManager()
      * If $sessionId is not provided, the AssessmentTestSession Storage Service implementation
      * must generate its own session ID. The ID generation algorithm is free, depending
      * on implementation needs.
+     * 
+     * Instantiating the AssessmentTestSession does not mean it is persisted. If you want
+     * to persist its state, call the persist() method.
      *
      * @param \qtism\data\AssessmentTest $test The test definition to be instantiated.
      * @param string $sessionId (optional) A $sessionId to be used to identify the instantiated AssessmentTest. If not given, an ID will be generated by the storage implementation.
@@ -112,4 +115,37 @@ abstract public function persist(AssessmentTestSession $assessmentTestSession);
      * @throws \qtism\runtime\storage\common\StorageException If an error occurs while retrieving the AssessmentTestSession object.
      */
     abstract public function retrieve(AssessmentTest $assessmentTest, $sessionId);
+
+    /**
+     * Whether or not an AssessmentTestSession object exits in persistence.
+     * 
+     * This method allows you to know whether or not an AssessmentTestSession object
+     * with a given $sessionId exists in the current storage.
+     * 
+     * @param string $sessionId
+     * @return boolean
+     * @throws \qtism\runtime\storage\common\StorageException If an error occurs while determining whether the AssessmentTestSession object exists in the storage.
+     */
+    abstract public function exists($sessionId);
+
+    /**
+     * Delete an AssessmentTestSession object from persistence.
+     * 
+     * This method enables you to delete an AssessmentTestSession object bound to
+     * a given $sessionId from the storage.
+     * 
+     * If an AssessmentTestSession object is effectively bound to $sessionId in the
+     * persistent storage, and is deleted successfully, this method returns true. 
+     * 
+     * However, if no AssessmentTestSession object could be found for $sessionId while deleting under
+     * normal circumstances, the method returns false.
+     * 
+     * Finally, if an unexpected error occurs while deleting the AssessmentTestSession object, a StorageException
+     * is thrown.
+     * 
+     * @param string $sessionId
+     * @return boolean
+     * @throws \qtism\runtime\storage\common\StorageException If an error occurs while deleting the AssessmentTestSession object.
+     */
+    abstract public function delete($sessionId);
 }

test/qtismtest/runtime/storage/binary/TemporaryQtiBinaryStorageTest.php

@@ -23,6 +23,7 @@
 use qtism\runtime\tests\AssessmentTestSessionState;
 use qtism\data\storage\xml\XmlCompactDocument;
 use qtism\runtime\storage\binary\TemporaryQtiBinaryStorage;
+use qtism\runtime\storage\common\StorageException;
 use \DateTime;
 use \DateTimeZone;
 
@@ -38,6 +39,10 @@ public function testTemporaryQtiBinaryStorage() {
         $storage = new TemporaryQtiBinaryStorage($sessionManager, new BinaryAssessmentTestSeeker($doc->getDocumentComponent()));
         $session = $storage->instantiate($test);
         $sessionId = $session->getSessionId();
+
+        // Instantiating the test session does not mean it is persisted. At the moment,
+        // it is not persistent yet.
+        $this->assertFalse($storage->exists($sessionId));
 
         $this->assertInstanceOf('qtism\\runtime\\tests\\AssessmentTestSession', $session);
         $this->assertEquals(AssessmentTestSessionState::INITIAL, $session->getState());
@@ -48,6 +53,11 @@ public function testTemporaryQtiBinaryStorage() {
 
         // A little bit of noisy persistence...
         $storage->persist($session);
+
+        // Now the test is persisted, we can try to know whether it exists in storage.
+        $this->assertTrue($storage->exists($sessionId));
+
+        // Let's retrive the session from storage.
         $session = $storage->retrieve($test, $sessionId);
 
         $this->assertEquals(AssessmentTestSessionState::INTERACTING, $session->getState());
@@ -557,8 +567,22 @@ public function testNonLinear() {
         $session->beginTestSession();
         $sessionId = $session->getSessionId();
 
+        // It's instantiated, but not persisted.
+
+        // Fun test #1, delete the non-persisted test session.
+        $this->assertFalse($storage->delete($sessionId));
+
         $storage->persist($session);
-        $session = $storage->retrieve($test, $sessionId);
+
+        // Fun test#2, delete the persisted test session.
+        $this->assertTrue($storage->delete($sessionId));
+
+        // Fun test#3, retrieve an unexisting test session.
+        try {
+            $session = $storage->retrieve($test, $sessionId);
+        } catch (StorageException $e) {
+            $this->assertTrue(true, "An Exception should be thrown because the test session does not exist anymore.");
+        }
     }
 
     public function testFiles() {