Serving multiple content types

问题

I'm creating a website and API with Express, I want to serve multiple content types (JSON, XML, HTML) on the same paths. In Express is there a better way to write the following:

// Serve JSON requests
app.get('/items/', function(req, res, next){
    if(!req.accepts('application/json')){
        return next();
    }

    res.end([1,2,3,4,5]);
});

// Serve XML requests
app.get('/items/', function(req, res, next){
    if(!req.accepts('application/xml')){
        return next();
    }

    res.end('<items><item>1</item><item>2</item><item>3</item><item>4</item><item>5</item></items>');
});

// Serve HTML requests
app.get('/items/', function(req, res, next){
    if(!req.accepts('text/html')){
        return next();
    }

    res.end('<ul><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li></ul>');
});

In particular, the above code seems rather repetitive, there's probably a more standard way to write this.

回答1:

There is response.format method which uses selects certain render method based on the "Accept" header. http://expressjs.com/4x/api.html#res.format

The response could look like this:

res.format({
  text: function(){
    res.send('hey');
  },

  html: function(){
    res.send('hey');
  },

  json: function(){
    res.send({ message: 'hey' });
  }
});

来源：https://stackoverflow.com/questions/23244174/serving-multiple-content-types