Nodejs Express framework caching

Question

I am using Nodejs and Express Js. Also I add NowJS to the Express Js to do some real-time stuffs.

In the configuration file I have

app.configure(\'pr         


        

Answer 1

The following code does the trick :

var cacheTime = 86400000*7;     // 7 days

app.use(express.static(__dirname + '/public',{ maxAge: cacheTime }));

However my public directory contains CSS as well as html files.

Is there a way i can cache css files only and not html.

I tried the setting "no-cache" in meta tag for html file but it didn't work.

Answer 2

EDIT: I was wrong, see eug's comment below

Connect includes caching middleware: http://senchalabs.github.com/connect/middleware-staticCache.html

so it should be as easy as

app.use(express.cache(...));
app.use(express.static(...));

Answer 3

Express is built on Connect, and Connect provides the "static" middleware. Here's the code under the hood for the caching:

if (!res.getHeader('Cache-Control')) res.setHeader('Cache-Control', 'public, max-age=' + (maxAge / 1000));

You can find that code here:

https://github.com/senchalabs/connect/blob/master/lib/middleware/static.js#L147

So as you can see Express is sending a "Cache-Control" header to the browser, telling him to cache that file for a period. So this isn't a "load a file once and then always serve it to all clients", but more of a "tell each client to cache the file the first time he downloads it" (which means all the clients will have to download that file once before it's cached for them).

Answer 4

The following code does the job:

app.use(function (req, res, next) {
    if (req.url.match(/^\/(css|js|img|font)\/.+/)) {
        res.setHeader('Cache-Control', 'public, max-age=3600'); // cache header
    }
    next();
});