CODEWITHSUNDEEP
node.jsexpress
Tan Nguyen
Tan Nguyen

Reputation: 3354

Nodejs Express framework caching

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('production', function() {
var oneYear = 31557600000;
app.use(express.static(__dirname + '/public', { maxAge: oneYear }));
app.use(express.errorHandler());});

And I run the application using this command:

$ NODE_ENV=production node app.js

However, the files(images, css, js) seem not to be cached, they are always served as new file.

P/s: I have just tested it with localhost, the cache seems to work on localhost, however, when uploading to the server, the cache is not working anymore.

Upvotes: 25

Views: 46755

Answers (4)

Felix
Felix

Reputation: 341

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();
});

Upvotes: 14

vashishatashu
vashishatashu

Reputation: 8172

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.

Upvotes: 10

Bulat
Bulat

Reputation: 2466

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(...));

Upvotes: 2

alessioalex
alessioalex

Reputation: 63683

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).

Upvotes: 26

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