Running an express app which for example has a route like /home and others. Now I want to change url to /en/home, /sp/home etc.
My requirement is to map these routes from /en/home to /home and similarly /sp/home to /home and add a header on request object on basis of /en and /sp
I want to write a middleware which will modify routes and extract information from it on basis of route as mentioned above.
I can use regex to do the second part but could not find a way to modify route on the fly.
You can try below middleware:
app.use('/en/home', function(req, res, next) {
req.headers.lang = 'en';
res.redirect('/home');
});
app.use('/sp/home', function(req, res, next) {
req.headers.lang = 'sp';
res.redirect('/home');
});
Related
I have a route where I built two GET APIs. I would like one to redirect from /download to /zip all while passing a parameter. The problem is I am getting a 404 for some reason the routes url is not being included in the redirect()
Here are the APIs.
// respond with xml from from static folder
router.get('/zip/:id', function (req, res) {
fileName = req.params.id
});
router.get('/download', function (req, res, next) {
var id = req.query.id
res.redirect('/zip?id='+ id);
});
module.exports = router;
I get a 404 when testing the URL:
localhost:8000/rest/pluto/v1/plugin/download?id=networktool
I am thinking it might be how I have the middleware setup but not real sure. I'm still new to node/express.
You are redirecting to a route that isn't actually defined. With your /zip/:id route definition:
router.get('/zip/:id', function (req, res) {
var fileName = req.params.id
});
The way that is defined, you have to have id information in the URL itself, so while the following routes would work:
/zip/networktool
/zip/1234
these routes would not:
/zip
/zip?id=networktool
/zip?id=1234
because Express is looking for the id to be built into the route itself. So you can do one of two things. You can either change your redirect to:
router.get('/download', function (req, res, next) {
res.redirect('/zip/'+ req.query.id);
});
or, you can modify your /zip route to make the id parameter optional with ?:
router.get('/zip/:id?', function (req, res) {
var fileName = (req.params.id) ? req.params.id : req.query.id;
});
I would recommend the first option, as the latter optional parameter only makes your zip route more complicated and require extra handling of whether id is actually passed to your route.
The path /zip/:id is expecting a path parameter not a query parameter.
You should redirect like this
res.redirect('/zip/'+ id);
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);
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.
I need an equivalent of following express.js code in simple node.js that I can use in middleware. I need to place some checks depending on the url and want to do it in a custom middleware.
app.get "/api/users/:username", (req,res) ->
req.params.username
I have the following code so far,
app.use (req,res,next)->
if url.parse(req.url,true).pathname is '/api/users/:username' #this wont be true as in the link there will be a actual username not ":username"
#my custom check that I want to apply
A trick would be to use this:
app.all '/api/users/:username', (req, res, next) ->
// your custom code here
next();
// followed by any other routes with the same patterns
app.get '/api/users/:username', (req,res) ->
...
If you only want to match GET requests, use app.get instead of app.all.
Or, if you only want to use the middleware on certain specific routes, you can use this (in JS this time):
var mySpecialMiddleware = function(req, res, next) {
// your check
next();
};
app.get('/api/users/:username', mySpecialMiddleware, function(req, res) {
...
});
EDIT another solution:
var mySpecialRoute = new express.Route('', '/api/users/:username');
app.use(function(req, res, next) {
if (mySpecialRoute.match(req.path)) {
// request matches your special route pattern
}
next();
});
But I don't see how this beats using app.all() as 'middleware'.
You can use node-js url-pattern module.
Make pattern:
var pattern = new UrlPattern('/stack/post(/:postId)');
Match pattern against url path:
pattern.match('/stack/post/22'); //{postId:'22'}
pattern.match('/stack/post/abc'); //{postId:'abc'}
pattern.match('/stack/post'); //{}
pattern.match('/stack/stack'); //null
For more information, see: https://www.npmjs.com/package/url-pattern
Just use the request and response objects as you would in a route handler for middleware, except call next() if you actually want the request to continue in the middleware stack.
app.use(function(req, res, next) {
if (req.path === '/path') {
// pass the request to routes
return next();
}
// you can redirect the request
res.redirect('/other/page');
// or change the route handler
req.url = '/new/path';
req.originalUrl // this stays the same even if URL is changed
});
I'm working on a basic blog in Express.js. Say I have route structure like this:
/blog/page/:page
I would also like a /blog route that is essentially an alias for /blog/page/1. How can I handle this easily in Express?
All routes are defined like such:
app.get('/path', function(req, res) {
//logic
});
Use res.redirect to tell the browser to redirect to /blog/page/1:
app.get('/blog', function(req, res) {
res.redirect('/blog/page/1');
});
app.get('/blog/page/:page', function(req, res) {
//logic
});
Use a shared route handler and default to page 1 if the page param is not passed:
function blogPageHandler(req, res) {
var page = req.params.page || 1;
//logic
}
// Define separate routes
app.get('/blog/page/:page', blogPageHandler);
app.get('/', blogPage);
// or combined, by passing an array
app.get(['/', '/blog/page/:page'], blogPageHandler);
// or using optional regex matching (this is not recommended)
app.get('/:_(blog/)?:_(page/)?:page([0-9]+)?', blogPageHandler);