如何传递来自快递服务器的数据以响应视图? [英] How can I pass data from express server to react views?

问题描述

我有一个简单的快递服务器，它与orientdb数据库建立了连接. 我需要传递来自Express的信息以回应观点. 例如，在快递中，我有:

I have a simple express server with a connection to a orientdb database. I need to pass information from express to react views. For example, in express I have:

router.get('/', function(req, res, next) {
  Vertex.getFromClass('Post').then(
    function (posts) {
      res.render('index', { title: 'express' });
    }
  );
});

因此，在此示例中，我需要在我的反应索引组件中包含posts变量以设置组件的状态. (我仅在前端使用反应，而不是服务器端)

So, in this example, I need to have in my react index component, the posts variable to set the state of the componenent. (I'm using react only in the frontend, not server-side)

class IndexPage extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      posts: []
    };
  }

  render() {
    return (
      <div>
        <Posts posts={posts} />
      </div>
    );
  }
}

我该如何从Express中获得回复?

How can I get the posts in react from express?

我发现也许我可以通过react发出ajax请求，但是我认为那不是最好的方法.

I found that maybe I can do an ajax request from react, but I think that that isn't the best way.

如果我需要实时获取帖子，例如使用socket.io，有什么区别?

If I need to get that posts in a real time way, using socket.io for example, what are the differences?

PD:在快速表达中，我可以使用一些模板引擎，例如把手或霍根(hogan).此模板引擎可以帮助您解决此主题吗?

PD: In express I have the possibility to use some template engine like handlebars or hogan. Can this template engines help in this topic?

谢谢！

推荐答案

我认为您最好的选择是确实从客户端发出某种网络请求.如果您希望保持应用程序的简单性，并且不想使用状态管理库(例如Redux)，则可以执行以下操作

I think your best option is to indeed make some kind of network request from the client. If you aim to keep the app simple and do not want a State Management library (e.g. Redux), you could do something like

class IndexPage extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      posts: []
    };
  }

  componentDidMount() {
    fetch('/') // or whatever URL you want
      .then((response) => response.json())
      .then((posts) => this.setState({
        posts: posts,
      });
  }

  render() {
    return (
      <div>
        <Posts posts={this.state.posts} />
      </div>
    );
  }
}

在您的response中，应该有一个posts集合的JSON表示形式.

In your response there should be a JSON representation of the posts collection.

还要注意render方法并访问posts.

有关Fetch API的更多信息，请参见 MDN (另请注意，您将需要为旧版浏览器使用一个polyfill.

For more on Fetch API see MDN (please also note that you will need a polyfill for older browsers for it).

对于socket.io，我将其实例存储在某个地方，并将其作为道具传递给组件.然后您可以做类似的事情

For socket.io I'd store the instance of it somewhere and pass it as a prop to the component. Then you can do something like

class IndexPage extends React.Component {
  ...
  componentDidMount() {
    this.props.socket.on('postReceived', this.handleNewPost);
  }
  handleNewPost = (post) => {
    this.setState({
      posts: [
        ...this.state.posts,
        post,
      ],
    });
  }
  ...
}

服务器端部分与此类似，例如参见 Socket.io聊天示例.

The server-side part is similar, see for example Socket.io Chat example.

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