phani phani - 5 months ago 41
Node.js Question

before and after hooks for a request in express (to be executed before any req and after any res)

ExpressJS middleware

req
,
res
,
next
have hooks like
.on
and
.pipe
.

But I'm looking for hooks for the
app.get
and
app.post
methods.

Answer

app.use() and middleware can be used for "before" and a combination of the 'close' and 'finish' events can be used for "after."

app.use(function (req, res, next) {
    function afterResponse() {
        res.removeListener('finish', afterResponse);
        res.removeListener('close', afterResponse);

        // action after response
    }

    res.on('finish', afterResponse);
    res.on('close', afterResponse);

    // action before request
    // eventually calling `next()`
});

app.use(app.router);

An example of this is the logger middleware, which will append to the log after the response by default.

Just make sure this "middleware" is used before app.router as order does matter.