What is nocache?
The nocache package is a middleware for Node.js applications that sets headers to disable client-side caching. This is particularly useful for ensuring that sensitive or frequently updated content is not stored in the user's cache, thereby enforcing content freshness and enhancing security.
What are nocache's main functionalities?
Disabling Caching
This code demonstrates how to use the nocache middleware in an Express application to disable client-side caching for all routes. By calling `app.use(nocache());`, all responses from the server will include headers that instruct the browser not to cache the content.
const express = require('express');
const nocache = require('nocache');
const app = express();
app.use(nocache());
app.get('/', (req, res) => {
res.send('Hello, World!');
});
app.listen(3000, () => {
console.log('Server is running on port 3000');
});
Other packages similar to nocache
helmet
Helmet is a collection of 14 smaller middleware functions that set HTTP response headers. One of its components, `helmet.noCache()`, offers similar functionality to nocache by setting headers to disable client-side caching. Helmet provides a broader range of security features beyond just disabling caching, making it a more comprehensive security solution.
cache-control
The cache-control package allows for fine-tuned control over the cache behavior of Node.js applications by setting the `Cache-Control` HTTP header. While nocache focuses on disabling caching altogether, cache-control offers more granular control, enabling developers to specify exactly how and when their content can be cached.
Middleware to turn off caching
It's possible that you've got bugs in an old HTML or JavaScript file, and with a cache, some users will be stuck with those old versions. This will (try to) abolish all client-side caching.
var nocache = require('nocache')
app.use(nocache())
This sets four headers, disabling a lot of browser caching:
Cache-Control: no-store, no-cache, must-revalidate, proxy-revalidate
Pragma: no-cache
Expires: 0
Surrogate-Control: no-store
If you want to crush the ETag
header as well, you can:
app.use(nocache({ noEtag: true }))
Caching has some real benefits, and you lose many of them here. Browsers won't cache resources with this enabled, although some performance is retained if you keep ETag support. It's also possible that you'll introduce new bugs and you'll wish people had old resources cached, but that's less likely.