Node.js and Express session handling - Back button problem

问题

I have a restricted area '/dashboard' in my Express application. I use a very small function to limit the access:

app.get('/dashboard', loadUser, function(req, res){
  res.render('dashboard', {
    username: req.session.username
  });
});

function loadUser(req, res, next){
  if (req.session.auth) {
    next();
  } else {
    res.redirect('/login');
  }
};

The problem is that when I logout a user by calling...

app.get('/logout', function(req, res){
  if (req.session) {
    req.session.auth = null;
    res.clearCookie('auth');
    req.session.destroy(function() {});
  }
  res.redirect('/login');
});

... the session is killed but when I hit Back Button in my browser I got the restricted page from browser's cache. This means no GET on '/dashboard' and no user login validation.

I tried using no-cache in meta (Jade Template) but it still doesn't work.

meta(http-equiv='Cache-Control', content='no-store, no-cache, must-revalidate')
meta(http-equiv='Pragma', content='no-cache')
meta(http-equiv='Expires', content='-1')

Anyone?

回答1:

Josh's answer sadly didn't work for me. But after some searching I found this question: What's the best way to deal with cache and the browser back button?

and adopted the answer there to this node.js/express problem. You just have to change the following line

res.header('Cache-Control', 'no-cache');

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

Now, everytime I use the browser back button, the page is reloaded and not cached.

* update for express v4.x *

// caching disabled for every route
server.use(function(req, res, next) {
  res.set('Cache-Control', 'no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0');
  next();
});

// otherwise put the res.set() call into the route-handler you want

回答2:

app.get('/dashboard', loadUser, function(req, res){
  res.header('Cache-Control', 'no-cache');
  res.header('Expires', 'Fri, 31 Dec 1998 12:00:00 GMT');

  res.render('dashboard', {
    username: req.session.username
  });
});

回答3:

Am using using Express ^4.16.3 and this worked for me as stated by @pkyeck.

I added it to my routes like this and it worked fine:

routes
.use(function(req, res, next) {
res.set('Cache-Control', 'no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0');
        next();
          })
          .get('/login', function(req, res, next){
              .....
})

回答4:

Simple solution is after clearing the session .. again redirect to the same route.. for example: route /sessionedpage has session variables .. after clicking logout button clear session variables by req.session.destroy(function() {}); after that you are tring to redirect home page ... INSTEAD of redirecting to home page.. redirect /sessionedpage (same route) ... Write if condition for /sessionedpage if(!res.sessions) then res.redirect('/home')

来源：https://stackoverflow.com/questions/6096492/node-js-and-express-session-handling-back-button-problem

标签

session

node.js

express