[Security] added SecurityContextInterface::getUser()

This changes helps the common use case of fetching the current user and better complies with the Law of Demeter (http://en.wikipedia.org/wiki/Law_of_Demeter).

Before (still works):

    $token = $context->getToken();
    $user = $token ? $token->getUser() : null;

After:

    $user = $context->getUser();

2 files changed, 23 insertions, 0 deletions

diff --git a/Core/SecurityContext.php b/Core/SecurityContext.php
index 6d11850..fc39407 100644
--- a/Core/SecurityContext.php
+++ b/Core/SecurityContext.php
@@ -89,4 +89,18 @@ class SecurityContext implements SecurityContextInterface
     {
         $this->token = $token;
     }
+
+    /**
+     * Returns the current user, if one exists.
+     *
+     * @return mixed Returns either an object which implements __toString(),
+     *               or a primitive string if there is a token, otherwise
+     *               returns null.
+     */
+    public function getUser()
+    {
+        if ($this->token) {
+            return $this->token->getUser();
+        }
+    }
 }
diff --git a/Core/SecurityContextInterface.php b/Core/SecurityContextInterface.php
index d0c7214..600f7b4 100644
--- a/Core/SecurityContextInterface.php
+++ b/Core/SecurityContextInterface.php
@@ -39,6 +39,15 @@ interface SecurityContextInterface
     function setToken(TokenInterface $token = null);
 
     /**
+     * Returns the current user, if one exists.
+     *
+     * @return mixed Returns either an object which implements __toString(),
+     *               or a primitive string if there is a token, otherwise
+     *               returns null.
+     */
+    function getUser();
+
+    /**
      * Checks if the attributes are granted against the current authentication token and optionally supplied object.
      *
      * @param array $attributes