express-cache-controller

Middleware for meddling with Cache-Control headers

Usage no npm install needed!

<script type="module">
  import expressCacheController from 'https://cdn.skypack.dev/express-cache-controller';
</script>

README

express-cache-controller

A simple and lightweight module for managing cache control headers from within your application. It also tries to provide a simple set of rules for common use cases such as setting 'max-age=0' when 'no-cache' is present by default.

Example

Configuring noCache easily:

app.use(cacheControl({
  noCache: true
}));

Creates a cache-control header of no-cache, max-age=0

Usage

To start using cacheControl, just use the middleware in your application:

app.use(cacheControl());

Default Cache Headers

When initialising the middleware you can set default options when you use it in your application:

app.use(cacheControl({
    maxAge: 5
}));

Overriding Defaults

Just set the cacheControl property of the response object after the cacheControl() middleware is loaded:

app.use(cacheControl({ maxAge: 60 }));
app.get('/', function (req, res, next){
  res.cacheControl = {
      maxAge: 30
  };

  res.send('hai');
});

This is useful in error conditions where you can setup cache headers before and after a request is processed:

app.use(cacheControl({ maxAge: 60} ));
app.get('/', function (req, res, next) {
  next(Error('BOOM!'));
});
app.use(function (err, req, res, next) {
  res.cacheControl = {
      maxAge: 5
  };

  res.status(500).send('oh no!');
});

Options

Name Value Description
private Boolean Adds 'private' flag, overrides 'public' option
public Boolean Adds 'public' flag
noStore Boolean Adds 'no-store' flag and includes noCache
noCache Boolean Adds 'no-cache' flag, sets maxAge to 0 and removes sMaxAge, staleIfError and staleWhileRevalidate
noTransform Boolean Adds 'no-transform' flag
mustRevalidate Boolean Adds 'must-revalidate' flag and removes staleIfError and staleWhileRevalidate
staleIfError Number Adds 'stale-if-error=%d' flag
staleWhileRevalidate Number Adds 'stale-while-revalidate=%d' flag
maxAge Number Adds 'max-age=%d' flag
sMaxAge Number Adds 's-maxage=%d' flag