I've the following middlewares:
injectParamMiddleware.js
module.exports = function(req, res, next) {
req.params.specialParam = 'specialValue';
next();
}
logParamMiddleware.js
module.exports = function(req, res, next) {
console.log(req.params.specialParam);
next();
}
SCENARIO 1
router.get('/resource/:resourceId',
injectParamMiddleware,
logParamMiddleware,
...MoreMiddlewares)
SCENARIO 2
router.use('/resource/:resourceId', injectParamMiddleware, logParamMiddleware);
router.get('/resource/:resourceId', ...MoreMiddlewares);
While running SCENARIO 1, I get specialValue logged in the console.
While running SCENARIO 2, I get undefined logged in the console.
I was expecting SCENARIO 2 to log specialValueas well.
Any help is really appreciated.
Thanks in advance.
EDIT: I'm using Express 4.14.0 and Node 6.10.3
Scenario 2 is causing an error 'by design' of express as the router is what creates params. It is getting overwritten
You can assign the var to another property in the app.use that will pass to the request
such as req.specialParam = 'specialValue'
app.param('/user/:name', (req, res) => {
req.specialParam = 'specialValue';
});
Other options are to modify the params wit the .param() method:
app.param('/user/:name', (req, res) => {});
or
app.route('/user/:name')
.all((req, res) => { ... console log here })
.get((req, res) => { ... })
Related
I am currently working on node.js + express + mongoDB project. I am trying to handle error that occurs when data cannot be received from database. I am simulating this by terminating mongod process in console and calling .get in Postman. Sadly instead of getting an error in Postman I only get Unhandled Promise Rejection in console. I read a lot of posts about error handling and implemented it according to this guide: https://expressjs.com/en/guide/error-handling.html. I would be grateful for any idea of how can I fix this.
The code:
Printing all courses:
router.get("/", async (req, res, next) => {
try {
const courses = await Course.find().sort("dishName");
res.send(courses);
} catch (ex) {
next(ex);
}
});
error.js:
module.exports = function (err, res, req, next) {
res.status(500).send(`500 Error`);
};
index.js
const error = require(`./middleware/error`);
app.use(error);
app.use(error) is placed as the last app.use
There is a minor mistake in your code. The order of the req and res parameters in the error handler function should not be changed.
// Error.js
module.exports = function (err, req, res, next) {
res.status(500).send(`500 Error`);
};
Forgive me for these heretical speeches, but I consider express to be the best library for api building from the developer experience point of view. But what stops me from using it everywhere is that everyone keeps saying (and confirming with benchmarks) that it is slow.
I try to choose an alternative for myself, but I canэt find what suits me.
For example with express I can simply organize the following structure:
userAuthMiddleware.js
export const userAuthMiddleware = (req, res, next) => {
console.log('user auth');
next();
};
adminAuthMiddleware.js
export const adminAuthMiddleware = (req, res, next) => {
console.log('admin auth');
next();
};
setUserRoutes.js
export const setUserRoutes = (router) => {
router.get('/news', (req, res) => res.send(['news1', 'news2']));
router.get('/news/:id', (req, res) => res.send(`news${req.params.id}`));
};
setAdminRoutes.js
export const setAdminRoutes = (router) => {
router.post('/news', (req, res) => res.send('created'));
router.put('/news/:id', (req, res) => res.send('uodated'));
};
userApi.js
imports...
const userApi = express.Router();
userApi.use(userAuthMiddleware);
// add handlers for '/movies', '/currency-rates', '/whatever'
setUserRoutes(userApi);
export default userApi;
server.js
imports...
const app = express();
app.use(bodyparser); // an example of middleware which will handle all requests at all. too lazy to come up with a custom
app.use('/user', userApi);
app.use('/admin', adminApi);
app.listen(3333, () => {
console.info(`Express server listening...`);
});
Now it is very easy for me to add handlers to different "zones", and these handlers will pass through the necessary middlewares. (For example users and admin authorization goes on fundamentally different logic). But this middlewares I add in one place and don't think about it anymore, it just works.
And here I am trying to organize a similar flexible routing structure on fastify. So far I haven't succeeded. Either the documentation is stingy, or I'm not attentive enough.
Fastify middlewares that added via 'use' gets req and res objects from the http library and not from the fastify library. Accordingly, it is not very convenient to use them - to pull something out of the body it will be a whole story.
Please give an example of routing in fastify a little more detailed than in the official documentation. For example similar to my example with user and admin on express.
I organize my routes like this:
fastify.register(
function(api, opts, done) {
api.addHook('preHandler', async (req, res) => {
//do something on api routes
if (res.sent) return //stop on error (like user authentication)
})
api.get('/hi', async () => {
return { hello: 'world' }
})
// only for authenticated users with role.
api.register(async role => {
role.addHook('preHandler', async (req, res) => {
// check role for all role routes
if (res.sent) return //stop on error
})
role.get('/my_profile', async () => {
return { hello: 'world' }
})
})
done()
},
{
prefix: '/api'
}
)
Now all request to api/* will be handled by fastify.
Does anyone know if it's possible to get the path used to trigger the route?
For example, let's say I have this:
app.get('/user/:id', function(req, res) {});
With the following simple middleware being used
function(req, res, next) {
req.?
});
I'd want to be able to get /user/:id within the middleware, this is not req.url.
What you want is req.route.path.
For example:
app.get('/user/:id?', function(req, res){
console.log(req.route);
});
// outputs something like
{ path: '/user/:id?',
method: 'get',
callbacks: [ [Function] ],
keys: [ { name: 'id', optional: true } ],
regexp: /^\/user(?:\/([^\/]+?))?\/?$/i,
params: [ id: '12' ] }
http://expressjs.com/api.html#req.route
EDIT:
As explained in the comments, getting req.route in a middleware is difficult/hacky. The router middleware is the one that populates the req.route object, and it probably is in a lower level than the middleware you're developing.
This way, getting req.route is only possible if you hook into the router middleware to parse the req for you before it's executed by Express itself.
FWIW, two other options:
// this will only be called *after* the request has been handled
app.use(function(req, res, next) {
res.on('finish', function() {
console.log('R', req.route);
});
next();
});
// use the middleware on specific requests only
var middleware = function(req, res, next) {
console.log('R', req.route);
next();
};
app.get('/user/:id?', middleware, function(req, res) { ... });
I know this is a little late, but for later Express/Node setups req.originalUrl works just fine!
Hope this helps
This nasty trick using prototype override will help
"use strict"
var Route = require("express").Route;
module.exports = function () {
let defaultImplementation = Route.prototype.dispatch;
Route.prototype.dispatch = function handle(req, res, next) {
someMethod(req, res); //req.route is available here
defaultImplementation.call(this, req, res, next);
};
};
req.route.path will work to get the path for the given route. But if you want the complete path including the path of the parent route, use something like
let full_path = req.baseUrl+req.route.path;
Hope it helps
You can take a look at Router().stack, which has all the routes defined. In your middleware you need to manually compare the available routes with the one called to define actions.
Does anyone know if it's possible to get the path used to trigger the route?
For example, let's say I have this:
app.get('/user/:id', function(req, res) {});
With the following simple middleware being used
function(req, res, next) {
req.?
});
I'd want to be able to get /user/:id within the middleware, this is not req.url.
What you want is req.route.path.
For example:
app.get('/user/:id?', function(req, res){
console.log(req.route);
});
// outputs something like
{ path: '/user/:id?',
method: 'get',
callbacks: [ [Function] ],
keys: [ { name: 'id', optional: true } ],
regexp: /^\/user(?:\/([^\/]+?))?\/?$/i,
params: [ id: '12' ] }
http://expressjs.com/api.html#req.route
EDIT:
As explained in the comments, getting req.route in a middleware is difficult/hacky. The router middleware is the one that populates the req.route object, and it probably is in a lower level than the middleware you're developing.
This way, getting req.route is only possible if you hook into the router middleware to parse the req for you before it's executed by Express itself.
FWIW, two other options:
// this will only be called *after* the request has been handled
app.use(function(req, res, next) {
res.on('finish', function() {
console.log('R', req.route);
});
next();
});
// use the middleware on specific requests only
var middleware = function(req, res, next) {
console.log('R', req.route);
next();
};
app.get('/user/:id?', middleware, function(req, res) { ... });
I know this is a little late, but for later Express/Node setups req.originalUrl works just fine!
Hope this helps
This nasty trick using prototype override will help
"use strict"
var Route = require("express").Route;
module.exports = function () {
let defaultImplementation = Route.prototype.dispatch;
Route.prototype.dispatch = function handle(req, res, next) {
someMethod(req, res); //req.route is available here
defaultImplementation.call(this, req, res, next);
};
};
req.route.path will work to get the path for the given route. But if you want the complete path including the path of the parent route, use something like
let full_path = req.baseUrl+req.route.path;
Hope it helps
You can take a look at Router().stack, which has all the routes defined. In your middleware you need to manually compare the available routes with the one called to define actions.
I have the following code :
app.get('/payment', function(req, res) {
// do lots of stuff
});
now I want to add the following :
app.post('/payment', function(req, res) {
req.myvar = 'put something here';
// now do the same as app.get() above
});
Obviously I want to reuse the code. I tried doing next('/payment') inside the post handler and put it above the get handler, but no luck, probably because they are different VERBs.
What are my options ?
Thanks.
Just lift out the middleware to its own function and use it in both routes.
function doLotsOfStuff (req, res) {
// do lots of stuff
}
app.get('/payment', doLotsOfStuff);
app.post('/payment', function(req, res, next) {
req.myvar = 'put something here';
next();
}, doLotsOfStuff);