从React中的状态而不是对象获取属性时出错

Question

尝试调用存储在反应状态的对象属性时出错。如果我将确切的roperty添加到一个状态它工作fint。但是，如果我将对象存储在我的状态并尝试调用该属性，我会收到错误消息：

Cannot read property '_embedded' of undefined

这是我的代码

var axios = require('axios');

    var App = React.createClass({
      getInitialState: function() {
        return {
          warningName: '',
          warningBase: {}
        },     
      }
    },

    componentDidMount: function() {
        var _this = this;
        var help = this.state.dietNames;
        
        axios     
            .get("http://api.baggid.com/users/61113f093cc04421aa3900d53e929d6a/profiles/2850/warninggroups/")
    .then(function(result) {
      _this.setState({
        warningName: result.data._embedded["bgd:warninggroup"][0]._embedded["bgd:warning"],
        warningBase: result.data._embedded["bgd:warninggroup"]
            });
        })

render(){
  console.log(this.state.warningName); //works
  console.log(this.state.warningBase[0]._embedded["bgd:warning"]); //doesn't work
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>