CODEWITHSUNDEEP
node.jsexpress
gelv
gelv

Reputation: 73

expressjs, difference on middleware callback use

A simple Express app:

var express = require('express');
var app = express();
var router = express.Router();

function test (req, res, next) {

}

I'm trying to figure out the difference on these two implementations:

router.use('/myRoute', test)

router.post('/myRoute', function (req, res) {

});

And: 

router.post('/myRoute', test, function (req, res) {
});

What I understand from the documentation (https://expressjs.com/en/4x/api.html#middleware-callback-function-examples) and (https://expressjs.com/en/4x/api.html#router.use) there is none. But that can't be the case?

Upvotes: 2

Views: 1694

Answers (1)

yBrodsky
yBrodsky

Reputation: 5041

In the code you put as an example there's a difference:

router.use('/myRoute', test)

This will apply the "test" function to whatever request comes to /myRoute (POST, PUT, GET, etc).

While this: 

router.post('/myRoute', test, function (req, res) {
});

Will only be applied to the POST request to /myRoute.

As for your question, the difference is that you either apply it globally, for example or you apply it only to a specific function. Depends the case you will use one or the other.

Upvotes: 3

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