So I have defined an express endpoint like:
router.get('/hello', function(req, res) {
res.send('hello');
});
Later on in the code, I have something like:
router.get('/gosilent', function(req, res) {
// When this is called, it removes /hello endpoint
// such that any subsequent calls to /hello will return standard 404.
});
How do I make it work? I know how to bind endpoints but how do I unbind then?
I'm using Express 4.0.
Thanks!
Related
I am trying to get the url parameter of an url request from the front in my nodejs backend.
fetch(`http://localhost:9000/sent/5768797675645657`)
Here is my app.js file :
app.use('/sent/:id', require('./routes/sent'));
And my /routes/sent.js file :
router.get('/', function(req, res) {
console.log(req.params)
})
How can I get the console.log(req.params) to work?
So, app.use accepts two parameters: the portion of the URL, and a callback function.
In order to your app works, you've to change the /routes/sent.js and make it exports the function, so it can be used when you're requiring it.
Just change it to
module.exports = function (req, res) {
console.log(req.params)
}
and you're ready to go!
I have a MEAN stack application and using Node.js and Express.js as back-end API.
Assuming I have a 'comments' route as follow
/* GET /comments listing. */
router.get("/", function(req, res, next) {
Comment.find(function(err, comments) {
if (err) return next(err);
res.json(comments);
});
});
And use it in my server like this:
var commentsRouter = require('./routes/comments');
...
app.use('/comments', commentsRouter);
My question is: Is there a way to prevent users to access http://mrUrl/comments in browser and deny the request with probably 403 Forbidden message but at the same time JavaScript file tries to access the same URL will receive a content message (in the example should be res.json(comments);)
Also, would it be possible to enable such a restriction for all routes once, not for each.
Yes, you can use a middleware.
A middleware is a function you can pass before or after the main function you are executing (in this case, GET comments)
the order of the function location matters, what comes first - executes first, and you implement it like so:
app.use(myBrowsingRestrictionMiddlewareFunction) // Runs
app.use('/comments', commentsRouter);
app.use('/account', accountRouter);
You can also use within a route handler:
app.post('/comments', myMakeSureDataIsAlrightFunction, myMainCreateCommentFunction, myAfterStatusWasSentToClientAndIWishToMakeAnotherInternalActionMiddleware);
The properties req, res, next are passed into the function automatically.
which means, myBrowsingRestrictionMiddlewareFunction receives them and you can use them like so:
export function myBrowsingRestrictionMiddlewareFunction(req, res, next) {
if (req.headers['my-special-header']) {
// custom header exists, then call next() to pass to the next function
next();
} else {
res.sendStatus(403);
}
}
EDIT
Expanding regards to where to place the middleware in the FS structure (personal suggestion):
What I like to do is to separate the router from app.js like so:
app.js
app.use('/', mainRouter);
router.js
const router = express.Router();
router.use(middlewareForAllRoutes);
router.use('/comments', commentsRouter);
router.use(middlewareForOnlyAnyRouteBelow);
router.use('/account', accountRouter);
router.use(middlewareThatWillBeFiredLast); // To activate this, remember to call next(); on the last function handler in your route.
commentsRouter.js
const router = express.Router();
router.use(middlewareForAllRoutesONLYFORWithinAccountRoute);
route.get('/', middlewareOnlyForGETAccountRoute, getAccountFunction);
router.post('/', createAccount);
So in express, we can have a chain of middleware, copies an example:
middleware = function(req, res){
res.send('GET request to homepage');
});
app.get('/', middleware, function (req, res) {
res.send('GET request to homepage');
});
What's the equivalent way to write this in koa2 please ?
I'm thinking of using it for the route, for each route i want to have a middleware to check if user is already logged in.
Thanks !
If you're simply interested in making sure a middlware runs for every route, all you have to do is register the middleware before you register your routing middelware.
app.use(middleware);
As long as you call this before you 'use' your router, it will be called for every request. Just make sure you call the next function. This is how your middleware might look like:
function middleware(ctx, next) {
// Authenticate user
// Eventually call this
return next();
}
What is the differences betwenn the 3 functions use/get/post with express?
In which case is better to use express.use instead of express.get/post?
app.use is used to load the middleware functions.
app.use example:
var myUseFunction = function (req, res, next) {
console.log('Hello World!');
next();
}
app.use(myUseFunction);
It does not have limitations for any restful api http verbs like POST, GET, PUT, PATCH, and DELETE.
app.get is route method is derived from one of the HTTP methods, and is attached to an instance of the express class.It serves the pupose of get request of apis.
GET method route
app.get('/', function (req, res) {
res.send('GET request to the page');
});
app.post is route method is derived from of the HTTP methods, and is attached to an instance of the express class. It serves the pupose of post request of apis.
POST method route
app.post('/', function (req, res) {
res.send('POST request to the page');
});
use is for middleware, e.g., all requests. It says it right in the docs:
Mounts the specified middleware function or functions at the specified path.
get is... for GET requests. post is for POST requests.
I am trying to fetch web pages using express static and below is the server code.
app.use(express.static('DIR/webfiles'));
app.get('/test', function(req, res) {
console.log("got req");
res.sendfile("login.html");
});
app.get('/', function(req, res) {
console.log("got req");
res.sendfile("login.html");
});
when I request for localhost:port/test (from browser), I am able to see login.html page and it prints "got req" on server end but when I request for localhost:port or localhost:port/ , I am getting some other file in webfiles folder. It does not print "got req". Is empty GET handler overridden by express static?
When I remove "app.use(express.static('DIR/webfiles'));" line, it is able to get empty GET request but doesn't work in way I want it to. Why it is not getting empty request and how to handle empty requests.
Express will process the various route handlers (including the static middleware) in order of declaration.
If you request /, the static middleware will check for a file called webfiles/index.html, and if it exists, it will be returned.
To override this behaviour, make sure that you declare your own route handler before the static middleware declaration:
// This will match requests to `/` and since it's declared before
// the static middleware, it will get to handle those requests.
app.get('/', function(req, res) {
console.log("got req");
res.sendfile("login.html");
});
app.use(express.static('DIR/webfiles'));