使用res.render时，如何让Express自动设置Content-Type？

Question

On Node.js, while using Jade as the template renderer, the only possible output of the res.render call is HTML.

But it does not include the corresponding Content-Type: text/html header automatically.

Is this by design? And if so, is there an easy way of implementing this without adding this header to all routes?

Answer 1

That depends on how you use jade. jade only does the rendering for you, it does not know the appropriate header for the rendered content.

res.setHeader('Content-Type', 'text/html'); //or text/plain
res.render('yourtemplate');

You should choose whatever header is most suitable for you.

Answer 2

I wrote a demo app to force Content-Type: text/html for all get requests. Then I tried disabling the function that sets that header, and that header still appears in my responses - so it does indeed seem to be set by default for me.

Are you sure that Content-Type is not set? What version of express and how are you viewing the headers? I'm on Express 3.4.1 and Chromium

// app.js
var express = require('express');
var app = express();

function setHTML(req, res, next){
  res.header('Content-Type', 'text/html');
  next();
};

app.set('views', __dirname);
app.set('view engine', 'jade');
app.use(app.router);

//app.get('*', setHTML);
app.get('/', function(req, res){
  res.render('template');
});

require('http')
.createServer(app)
.listen(3000, function(){
  console.log('Listening on 3000');  
})

// template.jade
!!!
html
  body
    h1 hello thar

//response headers
HTTP/1.1 200 OK
X-Powered-By: Express
Content-Type: text/html; charset=utf-8
Content-Length: 60
Date: Thu, 17 Oct 2013 03:50:46 GMT
Connection: keep-alive

Answer 3

you can override res.render method

app.use(function(req, res, next){

    var oldRender = res.render;
    res.render = function(){
        res.header('Content-Type', 'text/html');
        oldRender.apply(this, arguments);
    };

    next();
});

Do this just after creating your app.