No cache in Node.js server

Question

I have read that to avoid caching in Node.js, it is necessary to use:

res.header('Cache-Control', 'no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0'); 

But I don't know how to use it because I get errors when I put that line in my code.

My function (where I think I have to program the Cache-Control header) is:

function getFile(localPath, mimeType, res) {   fs.readFile(localPath, function(err, contents) {     if (!err) {       res.writeHead(200, {         "Content-Type": mimeType,         "Content-Length": contents.length,         "Accept-Ranges": "bytes",       });       // res.header('Cache-Control', 'no-cache');       res.end(contents);     } else {       res.writeHead(500);       res.end();     }   }); } 

Does anyone know how to put no cache in my code?

Answer 1

Make use of a middleware to add no-cache headers. Use this middleware where-ever you intend to turn caching off.

function nocache(req, res, next) {   res.header('Cache-Control', 'private, no-cache, no-store, must-revalidate');   res.header('Expires', '-1');   res.header('Pragma', 'no-cache');   next(); } 

Use the middleware in your routes definition:

app.get('/getfile', nocache, sendContent);  function sendContent(req, res) {   var localPath = 'some-file';   var mimeType = '';   fs.readFile(localPath, 'utf8', function (err, contents) {     if (!err && contents) {       res.header('Content-Type', mimeType);       res.header('Content-Length', contents.length);       res.end(contents);     } else {       res.writeHead(500);       res.end();     }   }); } 

Let me know if this works for you.