Access web services from AS in a Sinatra-like way

Nancy.as

package com.thefifthcircuit.nancy {
    import flash.net.URLLoader;
    import flash.net.URLRequest;
    import flash.net.URLVariables;
    import flash.net.URLRequestMethod;
    import flash.events.Event;
    import flash.events.IOErrorEvent;

    public class Nancy {
        private var host: String;

        public function Nancy(host: String) {
            this.host = host;
        }
        public function get(path: String, vars: Object, onComplete: Function = null, onError: Function = null) : void {
            req(URLRequestMethod.GET, path, vars, onComplete, onError);
        }
        public function post(path: String, vars: Object, onComplete: Function = null, onError: Function = null) : void {
            req(URLRequestMethod.POST, path, vars, onComplete, onError);
        }
        public function req(method: *, path: String, vars: Object = null, onComplete: Function = null, onError: Function = null) : void {
            var loader: URLLoader = new URLLoader();
            var request: URLRequest = new URLRequest(host + path);
            var variables: URLVariables = new URLVariables();

            vars = (vars != null) ? vars: {};

            if (vars != {}) {
                for (var key: *invars) variables[key] = vars[key];
                request.data = variables;
            }
            request.method = method;

            if (onComplete != null) loader.addEventListener(Event.COMPLETE, onComplete);
            if (onError != null) loader.addEventListener(IOErrorEvent.IO_ERROR, onError);

            loader.load(request);
        }
    }
}