Nodejs Express router middleware for all methods except get - node.js

Is there a way to exclude a specific method (say GET) when creating a middleware for route methods that share part of the path?
For example, I have a lot of routes of the form /api/item/*. I want to have something like this to check for bad data
router.all('/api/item/*', (req, res, next) => {
const { itemId } = req.body;
if (!itemId) return res.sendStatus(404);
/* rest of logic here */
next()
});
But obviously I don't want GET to also go through this logic as it will have no req.body.
Any thoughts?

As posted in comments above one solution is if (req.method === 'GET') return next();
Another I thought of shortly after (though, not as elegant) is to order my route declarations as such:
router.get(...);
router.all(...);
Thus only applying the data-checking logic to non-GET requests.

Related

Express 4: router syntax

I am using Express 4 with the new router. At least one thing continues to confuse me, and it is a syntax problem - I am wondering if there is a regex that can do what I want. I have a standard REST api, but I want to add batch updates, so that I can send all the info to update some users models with one request, instead of one PUT request per user, for example. Anyway, I currently route all requests to the users resources, like so:
app.use('/users, userRoutes);
in userRoutes.js:
router.get('/', function (req, res, next) {
//gets all users
});
router.put('/:user_id', function (req, res, next) {
//updates a single user
});
but now I want a route that captures a batch request, something like this:
router.put('/Batch', function (req, res, next) {
//this picks up an array of users from the JSON in req.body and updates all
});
in other words, I want something which translates to:
app.use('/usersBatch, function(req,res,next){
}
...but with the new router. I can't get the syntax right.
I tried this:
app.use('/users*, userRoutes);
but that doesn't work. Does anyone know how to design this?
I'm guessing that the call to [PUT] /users/Batch is being picked up by the [PUT] /users/:user_id route. The string /:user_id is used as a regular expression causing it to also collect /Batch.
You can either move /Batch before /:user_id in the route order, refine the regex of /:user_id to not catch /Batch or change /Batch to something that won't get picked up too early.
(plus all the stuff Michael said)
REST doesn't include a POST as a list syntax. That's because each URL in REST point to an individual resource.
As an internet engineer I haven't seen any bulk PUTs or POSTs, but that said, it's your app, so you can make whatever API you like. There are definitely use cases for it.
You'll still need to describe it to Express. I would do it like this:
var express = require('express');
var router = express.Router();
router.get('/', function (req, res) {}); // gets all users
router.post('/:user_id', function (req, res) {}); // one user
router.put('/:user_id', function (req, res) {}); // one user
router.patch('/:user_id', function (req, res) {}); // one user
router.delete('/:user_id', function (req, res) {}); // one user
app.use('/user', router); // Notice the /user/:user_id is *singular*
var pluralRouter = express.Router();
pluralRouter.post('/', function (req, res) {
// req.body is an array. Process this array with a foreach
// using more or less the same code you used in router.post()
});
pluralRouter.put('/', function (req, res) {
// req.body is another array. Have items in the array include
// their unique ID's. Process this array with a foreach
// using +/- the same code in router.put()
});
app.use('/users', pluralRouter); // Notice the PUT /users/ is *plural*
There are other ways to do this. Including putting comma-delimited parameters in the URL. E.g.
GET /user/1,2,3,4
But this isn't that awesome to use, and vague in a PUT or POST. Parallel arrays are evil.
All in all, it's a niche use case, so do what works best. Remember, the server is built to serve the client. Figure out what the client needs and serve.

using middlewares for specific namespaces in restify

I would like to use a middleware for checking users credentials only for some routes (those that start with /user/), but to my surprise server.use does not take a route as first argument and with restify-namespace server.use effect is still global.
Is there other way better than passing my auth middleware to all routes alongside the controller?
I think I'm going to just use server.use and inside the middleware make the following route check:
if (req.url.indexOf('/user/') !== 0) {
return next();
}
Unfortunately restify doesn't seem to be like express, which support the * operator. Hence, What I would suggest is grouping the routes that you desire together and apply a .use before them.
That is:
server.get('/test', function(req, res, next) {
// no magic here. server.use hasn't been called yet.
});
server.use(function(req, res, next) {
// do your magic here
if(some condition) {
// magic worked!
next(); // call to move on to the next middleware.
} else {
// crap magic failed return error perhaps?
next(new Error('some error')); // to let the error handler handle it.
}
});
server.get('/admin/', function(req, res, next) {
// magic has to be performed prior to getting here!
});
server.get('/admin/users', function(req, res, next) {
// magic has to be performed prior to getting here!
});
However, I would personally advocate the use of express, but choose whatever fits your need.

add middleware to all routes but a few

how can I add middleware to all possible routes except for these that match a given expression?
I know how to add a middleware to ones that match an expression:
app.all('/test/*', requireLogin);
but I want to require login in all routes except for a few that have a specific prefix in their paths.
If you are using express 3.x series you are out of luck here. You need to hack the middle ware to to check the the path.
app.use(function(err, req, res, next){
if(canRouteSkipLogin(req.path)
next();
else{
//Do the auth logic
}
});
canRouteSkipLogin = function(path){
//logic to find the path which can skip login
}
While in express 4.0 you can do it much easier way.
var authRoutes = express.Router();
var nonAuthRoutes = express.Router();
authRoutes.use(function(req, res, next) {
//Do Auth Logic here
});
Hope this explains.
The only way I've been able to do this is to just explicitly code for it with a guard clause in the middleware itself. So the middleware always gets called, it checks req.path against the bypass regex, and if so, just calls next() immediately and returns. This is the pattern used by things like the expressjs body-parser (via the type-is module) to no-op themselves based on checking that a given request doesn't require them to do anything.

Using Express 4 how to redirect to my own route without losing req and response data?

I have my application structured with 3 Routes (api, admin, default). Each lives in there own file and has it's own middleware and exports a Route. The problem I am facing is when I want to forward to another route that lives on a different router. Essentially I want to call the same function so that I am not serving up the same view from multiple locations.
I don't want to user res.redirect('/someplace') because I want to be able to pass the req and res objects on to the method.
|-app.js
|-routes
|---admin.js
|---api.js
|---default.js
The routes are required and used in app.js as follows
app.use('/api', require('./routes/api')(passport);
app.use('/admin', require('./routes/admin')(passport);
app.use('/', require('./routes/default')(passport);
Inside of admin if have a situation where I need redirect to login and pass some data
// authenticates all routes for the admin router
router.use(function(req, res, next){
if(req.isAuthenticated()){
return next();
}
res.flashMessage.push('Session expired'); //is lost after redirect
res.redirect('/login');
//do I need to restructure my whole app so that I don't
//have to call res.redirect('login')
});
Any ideas on how to structure this? Do I need to export every method and keep all of my routes in one router file? That doesn't very clean, but if the functions are somewhere else it may be too messy.
You can forward it by calling the next callback ,but only if you do not use any paths.
app.use(function(req, res, next) {
// ... api
next();
});
app.use(function(req, res, next) {
// ... admin
next();
});
Another option is use * that will match all paths:
app.use("*", function(req, res, next) {
var path = req.path; // just example how it can be done
if (path === "/api") {
// ...
path = "/admin";
}
if (path === "/admin") {
// ...
}
});
Edit:
I don't think that express has something like next('/login'); ,so basically function that can forward a request to another path and I don't think that is right to have something like this. If a client ask for /admin you should send this particular page and not the page that is under /login. If you want to send back to a client the login page than just redirect it as you did it in your question. I understand that you want to keep the req, res ,but then is the problem in the proposal/structure of your webapp.

Express, multiple routes to same function

I am mimicking another api. I would also like to provide a different (better IMHO) api as well.
// this is url I need to support
api.post('/books/updateBook', function(req, res) {
...
});
// Would also like to support
api.put('/books/:bookId', function(req, res) {
...
});
I could easily do:
var updateBook = function(req, res) {
...
}
// this is url I need to support
api.post('/books/updateBook', updateBook);
// Would also like to support
api.put('/books/:bookId', updateBook);
Perfectly acceptable right? Being new to express I am wondering if there is a more 'express' way to handle this. I know you can use regex, but I am not sure you can map regex across different HTTP verbs (POST vs PUT).
Thoughts?
api.all('/books/:bookId', function (req, res, next) {
if (req.method === 'PUT' || req.method === 'POST) {
//get your groove on
} else {
next();
}
});
You can combine verbs in express, you just use all and examine the method, if it matches, handle the request other wise pass it down the handler chain (with next();).
That being said I think you're doing it right, there's no reason route handlers need to be lamdas.

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