vue-resource的请求报错

引入的js：


代码：

var vm = new Vue({

        el: "#app",
        ready: function(){
             this.$http.get('data/list.txt', function(data) {
                 console.log(data);
            }).error(function(data, status, request) {
                console.log('fail' + status + "," + request);
            })
        },
        data:{}
    });

报错：index.html:24 Uncaught TypeError: Cannot read property 'get' of undefined