--- /dev/null
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Config\Resource;
+
+/**
+ * ResourceInterface is the interface that must be implemented by all Resource classes.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+interface ResourceInterface
+{
+ /**
+ * Returns a string representation of the Resource.
+ *
+ * This method is necessary to allow for resource de-duplication, for example by means
+ * of array_unique(). The string returned need not have a particular meaning, but has
+ * to be identical for different ResourceInterface instances referring to the same
+ * resource; and it should be unlikely to collide with that of other, unrelated
+ * resource instances.
+ *
+ * @return string A string representation unique to the underlying Resource
+ */
+ public function __toString();
+
+ /**
+ * Returns true if the resource has not been updated since the given timestamp.
+ *
+ * @param int $timestamp The last time the resource was loaded
+ *
+ * @return bool True if the resource has not been updated, false otherwise
+ *
+ * @deprecated since 2.8, to be removed in 3.0. If your resource can check itself for
+ * freshness implement the SelfCheckingResourceInterface instead.
+ */
+ public function isFresh($timestamp);
+
+ /**
+ * Returns the tied resource.
+ *
+ * @return mixed The resource
+ *
+ * @deprecated since 2.8, to be removed in 3.0. As there are many different kinds of resource,
+ * a single getResource() method does not make sense at the interface level. You
+ * can still call getResource() on implementing classes, probably after performing
+ * a type check. If you know the concrete type of Resource at hand, the return value
+ * of this method may make sense to you.
+ */
+ public function getResource();
+}