Add support to prefix url on MenuItem

src/MenuItem.php

@@ -59,6 +59,13 @@ class MenuItem implements ArrayableContract
      */
     protected $hideWhen;
 
+    /**
+     * Prefix URL.
+     *
+     * @var string|null
+     */
+    protected $prefixUrl;
+
     /**
      * Constructor.
      *
@@ -91,6 +98,20 @@ protected static function setIconAttribute(array $properties)
         return $properties;
     }
 
+     /**
+     * Set Prefix URL.
+     *
+     * @param string $prefixUrl
+     *
+     * @return $this
+     */
+    public function setPrefixUrl($prefixUrl)
+    {
+        $this->prefixUrl = $prefixUrl;
+
+        return $this;
+    }
+
     /**
      * Get random name.
      *
@@ -202,6 +223,20 @@ public function route($route, $title, $parameters = array(), $order = 0, $attrib
         return $this->add(compact('route', 'title', 'order', 'attributes'));
     }
 
+    /**
+     * Format URL.
+     *
+     * @param string $url
+     *
+     * @return string
+     */
+    protected function formatUrl($url)
+    {
+        $uri = !is_null($this->prefixUrl) ? $this->prefixUrl . $url : $url;
+
+        return $uri == '/' ? '/' : ltrim(rtrim($uri, '/'), '/');
+    }
+
     /**
      * Create new menu item  and set the action to url.
      *
@@ -217,12 +252,14 @@ public function url($url, $title, $order = 0, $attributes = array())
             $arguments = func_get_args();
 
             return $this->add([
-                'url' => array_get($arguments, 0),
+                'url' => $this->formatUrl(array_get($arguments, 0)),
                 'title' => array_get($arguments, 1),
                 'attributes' => array_get($arguments, 2),
             ]);
         }
 
+        $url = $this->formatUrl($url);
+
         return $this->add(compact('url', 'title', 'order', 'attributes'));
     }