Session: Implement ArrayAccess

[lhc/web/wiklou.git] / includes / session / Session.php

diff --git a/includes/session/Session.php b/includes/session/Session.php
index 4ad69ae..d654ff1 100644 (file)
--- a/includes/session/Session.php
+++ b/includes/session/Session.php
@@ -23,6 +23,7 @@
 
 namespace MediaWiki\Session;
 
+use Psr\Log\LoggerInterface;
 use User;
 use WebRequest;
 
@@ -41,24 +42,28 @@ use WebRequest;
  * The Session object also serves as a replacement for PHP's $_SESSION,
  * managing access to per-session data.
  *
- * @todo Once we drop support for PHP 5.3.3, implementing ArrayAccess would be nice.
  * @ingroup Session
  * @since 1.27
  */
-final class Session implements \Countable, \Iterator {
+final class Session implements \Countable, \Iterator, \ArrayAccess {
        /** @var SessionBackend Session backend */
        private $backend;
 
        /** @var int Session index */
        private $index;
 
+       /** @var LoggerInterface */
+       private $logger;
+
        /**
         * @param SessionBackend $backend
         * @param int $index
+        * @param LoggerInterface $logger
         */
-       public function __construct( SessionBackend $backend, $index ) {
+       public function __construct( SessionBackend $backend, $index, LoggerInterface $logger ) {
                $this->backend = $backend;
                $this->index = $index;
+               $this->logger = $logger;
        }
 
        public function __destruct() {
@@ -271,7 +276,7 @@ final class Session implements \Countable, \Iterator {
        /**
         * Fetch a value from the session
         * @param string|int $key
-        * @param mixed $default
+        * @param mixed $default Returned if $this->exists( $key ) would be false
         * @return mixed
         */
        public function get( $key, $default = null ) {
@@ -281,6 +286,7 @@ final class Session implements \Countable, \Iterator {
 
        /**
         * Test if a value exists in the session
+        * @note Unlike isset(), null values are considered to exist.
         * @param string|int $key
         * @return bool
         */
@@ -419,6 +425,39 @@ final class Session implements \Countable, \Iterator {
                return key( $data ) !== null;
        }
 
+       /**
+        * @note Despite the name, this seems to be intended to implement isset()
+        *  rather than array_key_exists(). So do that.
+        */
+       public function offsetExists( $offset ) {
+               $data = &$this->backend->getData();
+               return isset( $data[$offset] );
+       }
+
+       /**
+        * @note This supports indirect modifications but can't mark the session
+        *  dirty when those happen. SessionBackend::save() checks the hash of the
+        *  data to detect such changes.
+        * @note Accessing a nonexistent key via this mechanism causes that key to
+        *  be created with a null value, and does not raise a PHP warning.
+        */
+       public function &offsetGet( $offset ) {
+               $data = &$this->backend->getData();
+               if ( !array_key_exists( $offset, $data ) ) {
+                       $ex = new \Exception( "Undefined index (auto-adds to session with a null value): $offset" );
+                       $this->logger->debug( $ex->getMessage(), array( 'exception' => $ex ) );
+               }
+               return $data[$offset];
+       }
+
+       public function offsetSet( $offset, $value ) {
+               $this->set( $offset, $value );
+       }
+
+       public function offsetUnset( $offset ) {
+               $this->remove( $offset );
+       }
+
        /**@}*/
 
 }