nodejs perform common action for all request

Question

I am using node js with express. Now i need to perform an common action for all requests ex. cookie checking

app.get('/',function(req, res){
   //cookie checking
   //other functionality for this request 
}); 

app.get('/show',function(req, res){
   //cookie checking
   //other functionality for this request 
}); 

Here cookie checking is an common action for all request. So how can i perform this with out repeating the cookie checking code in all app.get.

Suggestions for fixing this? Thanks in advance

Answer 1

Check out the loadUser example from the express docs on Route Middleware. The pattern is:

function cookieChecking(req, res, next) {
    //cookie checking
    next();
}


app.get('/*', cookieChecking);

app.get('/',function(req, res){
    //other functionality for this request 
}); 

app.get('/show',function(req, res){
   //other functionality for this request 
}); 

Answer 2

app.all or use a middleware.

Answer 3

Using middleware is high reccomended, high performable and very cheap. If the common action to be performed is a tiny feature I suggest to add this very simple middleware in your app.js file:

...
app.use(function(req,res,next){
    //common action
    next();
});...

If you use router : write the code before the app.use(app.router); instruction.