Merge pull request #123 from phpcr/relative-path

Relativize path

Author: lsmith77

src/PHPCR/Util/PathHelper.php

@@ -196,6 +196,28 @@ public static function absolutizePath($path, $context, $destination = false, $th
         return self::normalizePath($path, $destination, $throw);
     }
 
+    /**
+     * Make an absolute path relative to $context.
+     *
+     * ie. $context . '/' . PathHelper::relativePath($path, $context) === $path
+     *
+     * Input paths are assumed to be normalized.
+     *
+     * @param string $path    The absolute path to a node
+     * @param string $context The absolute path to an ancestor of $path
+     * @param bool $throw     Whether to throw exceptions on invalid data.
+     *
+     * @return string The relative path from $context to $path
+     */
+    public static function relativizePath($path, $context, $throw = true)
+    {
+        if ($context !== substr($path, 0, strlen($context))) {
+            return self::error("$path is not within $context", $throw);
+        }
+
+        return ltrim(substr($path, strlen($context)), '/');
+    }
+
     /**
      * Get the parent path of a valid absolute path.
      *

tests/PHPCR/Tests/Util/PathHelperTest.php

@@ -186,6 +186,49 @@ public static function dataproviderAbsolutizePathInvalid()
         );
     }
 
+    // relativizePath tests
+
+    /**
+     * @dataProvider dataproviderRelativizePath
+     */
+    public function testRelativizePath($inputPath, $context, $outputPath)
+    {
+        $this->assertSame($outputPath, PathHelper::relativizePath($inputPath, $context));
+    }
+
+    public static function dataproviderRelativizePath()
+    {
+        return array(
+            array('/parent/path/child', '/parent', 'path/child'),
+            array('/child', '/', 'child'),
+        );
+    }
+
+    /**
+     * @expectedException \PHPCR\RepositoryException
+     * @dataProvider dataproviderRelativizePathInvalid
+     */
+    public function testRelativizePathInvalidThrow($inputPath, $context)
+    {
+        PathHelper::relativizePath($inputPath, $context);
+    }
+
+    /**
+     * @dataProvider dataproviderRelativizePathInvalid
+     */
+    public function testRelativizePathInvalidNoThrow($inputPath, $context)
+    {
+        $this->assertFalse(PathHelper::relativizePath($inputPath, $context, false));
+    }
+
+    public static function dataproviderRelativizePathInvalid()
+    {
+        return array(
+            array('/path', '/context'),
+            array('/parent', '/parent/child'),
+        );
+    }
+
     // getParentPath tests
 
     /**