Added basePath support in Router for pathFor()

Slim/Router.php

@@ -37,6 +37,13 @@ class Router extends RouteCollector implements RouterInterface
      */
     private $routeParser;
 
+    /**
+     * Base path used in pathFor()
+     *
+     * @var string
+     */
+    protected $basePath = '';
+
     /**
      * Routes
      *
@@ -74,6 +81,24 @@ public function __construct(RouteParser $parser = null, DataGenerator $generator
         $this->routeParser = $parser;
     }
 
+    /**
+     * Set the base path used in pathFor()
+     *
+     * @param string $basePath
+     *
+     * @return self
+     */
+    public function setBasePath($basePath)
+    {
+        if (!is_string($basePath)) {
+            throw new InvalidArgumentException('Router basePath must be a string');
+        }
+
+        $this->basePath = $basePath;
+
+        return $this;
+    }
+
     /**
      * Add route
      *
@@ -264,6 +289,10 @@ public function pathFor($name, array $data = [], array $queryParams = [])
         }
         $url = implode('', $segments);
 
+        if ($this->basePath) {
+            $url = $this->basePath . $url;
+        }
+
         if ($queryParams) {
             $url .= '?' . http_build_query($queryParams);
         }