npm请求包的拦截器

Question

I am working on an Express JS web application. I have 3 layers in my application. External API server, Express and Angular as front end. So each AJAX requests from front end should pass through express in order to reach the API server and the same way, response too. Authentication is managed by API server. When I send request to login from Angular, it will reach Express first, then Express will sent a request to API server, API server will send the Authentication token to Express and Express will pass it to the front end. So all the request from Angular will send the Authentication token as header to Express, express will send the corresponding request with the access token. This how my application works. I know little complicated. Now I am retrieving the access token from front end request and pass it to the API server in all the Controllers. What I want to do is, I have to write an interceptor which will globally retrieve the access token from the front end request and will pass to the API server.

Answer 1

You can add an application middleware in your main file ie (app.js/server.js) above your routes.

function interceptor(req, res, next) {
  let headers = req.headers;
  headers.someHeader = 'xyz'; // add your headers like this 
  request('your server url here', {
    method: req.method,
    headers: headers,
  }, (err, response, body) => {
    if (err) {
      next(err);
    }
    else {
      console.log(response.request.headers);
      res.send('OK');
    }
  });
}
app.use(interceptor);