[api] Attach extra objects to thisArg in http

lib/director/http/index.js

@@ -59,6 +59,15 @@ Router.prototype.on = function (method, path) {
   director.Router.prototype.on.call(this, method, path, route);
 };
 
+//
+// ### function attach (func)
+// ### @func {function} Function to execute on `this` before applying to router function
+// Ask the router to attach objects or manipulate `this` object on which the
+// function passed to the http router will get applied
+Router.prototype.attach = function (func) {
+  this._attach = func;
+};
+
 //
 // ### function dispatch (method, path)
 // #### @req {http.ServerRequest} Incoming request to dispatch.
@@ -81,6 +90,10 @@ Router.prototype.dispatch = function (req, res, callback) {
       stream,
       error;
 
+  if (this._attach) {
+    this._attach.call(thisArg);
+  }
+
   if (!fns || fns.length === 0) {
     error = new exports.NotFound('Could not find path: ' + req.url)
     if (callback) {