I am new to express and node, I working on a task where I want to add some json data to middleware request, here is the approach I am following:
In my middleware I want to add some details to request like current date and time and then extract the URL path. Here is the code I came up with:
var express = require('express');
var app = express();
module.exports = app.use('/some-url', function(req, res, next) {
let logdetails = {
id: "some-id",
datetime: Date.now(),
path: '/path-in-url'
}
req.logdetails= logdetails;
next();
} );
I am using module.exports so it this function is exported. But it is giving errors. Also what is the correct way to access the URL path, for example if URL is /users/john then I want to extract /john and my middleware should be applied only when URL starts with /users.
Also what is the correct way to access the URL path, for example if
URL is /users/john then I want to extract /john
If your request url is /users/john then req.path will give you the path of the request url, i.e. /users/john. To extract john, you can use named route parameters and define your route as /users/:name. After using named route parameter in your route, if your request url is /users/john, req.params.name will give you the route parameter, i.e. john. For more details, take a look at req.params on express docs
and my middleware should be applied only when URL starts with /users
following middleware will only run when request path is /users
app.use('/users', (req, res, next) => {
...
}
If you want the middleware then just export the middleware function. Not the Whole app.use part. I think app.use returns an Express object. And :param in your url will make sure that you can access that parameter. You can check out more about path patterns here
middleware.js
module.exports = function(req, res, next) {
let logdetails = {
id: "some-id",
datetime: Date.now(),
path: '/path-in-url'
}
req.logdetails= logdetails;
next();
}
Your other main.js file:
const express = require('express');
const app = express();
const middleWare = require('./middleware')
app.use('/users/:name', middleWare, (req, res)=>{
//you can access logDetails
// and the name
const name = req.params.name;//This will be john for /users/john
const logDetails = req.logdetails;
})
req.originalUrl returns the url path like shown below
// GET /search?q=something
console.dir(req.originalUrl)
// => '/search?q=something'
source: https://expressjs.com/en/api.html
Similarly, get the URL path and split the string accordingly and apply the condition you need.
Here if your originalPath is /users/john then
const result = "/users/john".split("/")
would result in ["", "users", "john"]
Check if the result[1]==="users" and write your condition in the middleware.
You don't have to export the middle ware.
middleware.js
module.exports = {
handler: (req, res, next) => {
const userName = req.params.name;
// add payload to request
next();
}
}
app.js
middleware = require("middleware");
app.use('/users/:name', middleware.handler);
Concerning URL path access you could get access using request params, e.g
app.use('/users/:name', (req, res, next) => {
const userName = req.params.name;
// add payload to request
next();
});
1. Register your specific URL - `/users/:name`, where `:name` is dynamic params e.g *john*
2. Grab params in the callback
Related
router.get("/(A|B)/account/", async (req, res) => {});
How to do I reference the (A|B) inside of the async function?
I guess your route responsibility is getting account information of only A or B. So let's change your router path to /account/:name(A|B), then your express router will look like this:
router.get("/account/:name(A|B)", async (req, res) => {
const name = req.params; // A or B
});
Only 2 kinds of requests are handled by this router:
GET /account/A
or
GET /account/B
I have an Express application with a router, here is the example of the router:
const router = require('express-promise-router')();
const users = require('./users');
const validate = require('./validate');
router.get('/users', users.list);
router.get('/users/:id', users.get);
// other routes here
module.exports = router;
Now I want to add a middleware that validates each query, like that (this is not the working example, it's just to show the idea of what I want to accomplish):
const schemas = {
'/users': 'some validation schema',
'/users/:id': 'another validation'
}
module.exports = (req, res, next) => {
const url = req.originalUrl; // This is where I'm stuck.
if (!schemas[url]) {
// throw new error that validation failed
}
// validating somehow
if (!req.validate(schemas[url])) {
// throw new error that validation failed
}
return next();
}
And for this, I need to get the middlelware mount folder (like '/users/:id' for '/users/557'). I've tried to use req.originalUrl, but it returns the full URL path instead of the mount folder.
How can I achieve this? And if there's no way, how can I write my validation middleware another way to make it work?
Inside req.route you will get the path of API.
Check this screenshot
I have an ExpressJS routing for my API and I want to call it from within NodeJS
var api = require('./routes/api')
app.use('/api', api);
and inside my ./routes/api.js file
var express = require('express');
var router = express.Router();
router.use('/update', require('./update'));
module.exports = router;
so if I want to call /api/update/something/:withParam from my front end its all find, but I need to call this from within another aspect of my NodeJS script without having to redefine the whole function again in 2nd location
I have tried using the HTTP module from inside but I just get a "ECONNREFUSED" error
http.get('/api/update/something/:withParam', function(res) {
console.log("Got response: " + res.statusCode);
res.resume();
}).on('error', function(e) {
console.log("Got error: " + e.message);
});
I understand the idea behind Express is to create routes, but how do I internally call them
The 'usual' or 'correct' way to handle this would be to have the function you want to call broken out by itself, detached from any route definitions. Perhaps in its own module, but not necessarily. Then just call it wherever you need it. Like so:
function updateSomething(thing) {
return myDb.save(thing);
}
// elsewhere:
router.put('/api/update/something/:withParam', function(req, res) {
updateSomething(req.params.withParam)
.then(function() { res.send(200, 'ok'); });
});
// another place:
function someOtherFunction() {
// other code...
updateSomething(...);
// ..
}
This is an easy way to do an internal redirect in Express 4:
The function that magic can do is: app._router.handle()
Testing: We make a request to home "/" and redirect it to otherPath "/other/path"
var app = express()
function otherPath(req, res, next) {
return res.send('ok')
}
function home(req, res, next) {
req.url = '/other/path'
/* Uncomment the next line if you want to change the method */
// req.method = 'POST'
return app._router.handle(req, res, next)
}
app.get('/other/path', otherPath)
app.get('/', home)
I've made a dedicated middleware for this : uest.
Available within req it allows you to req.uest another route (from a given route).
It forwards original cookies to subsequent requests, and keeps req.session in sync across requests, for ex:
app.post('/login', async (req, res, next) => {
const {username, password} = req.body
const {body: session} = await req.uest({
method: 'POST',
url: '/api/sessions',
body: {username, password}
}).catch(next)
console.log(`Welcome back ${session.user.firstname}!`
res.redirect('/profile')
})
It supports Promise, await and error-first callback.
See the README for more details
Separate your app and server files with the app being imported into the server file.
In the place you want to call your app internally, you can import you app as well as 'request' from 'supertest'. Then you can write
request(app).post('/someroute').send({
id: 'ecf8d501-5abe-46a9-984e-e081ac925def',
etc....
});`
This is another way.
const app = require('express')()
const axios = require('axios')
const log = console.log
const PORT = 3000
const URL = 'http://localhost:' + PORT
const apiPath = (path) => URL + path
app.get('/a', (req, res) => {
res.json('yoy')
})
app.get('/b', async (req, res) => {
let a = await axios.get(apiPath('/a'))
res.json(a.data)
})
app.listen(PORT)
const app = express();
var router = require('express').Router({mergeParams: true});
const payloadMiddleware = (req, resp, next) => {
console.log('A:',req.params);
const {params, query} = req;
const payload = req.body;
req.my_params = { params, query, payload };
next();
};
router.use(payloadMiddleware);
router.get('/inventory/:itemID/price', async function GetPrice(req, res, next) {
console.log('B', req.my_params);
console.log('C', req.params);
}
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
app.use('/', router);
server = app.listen(port);
GET /inventory/abc/price?a=1&b=2 yields
A: {} # unclear why this is empty
B: { params: {},
query: { a: '1', b: '2' },
payload: {} }
C: {itemID: 'abc'}
So I'm confused: I expect my middleware to find params in req, construct the new object, and assign it to req as my_params, then pass that to the inventory handler. And this is partially happening, in that the querystring is being parsed and then assigned in my middleware. Why is req.params === {} in my middleware function, but req.params = {itemID: 'abc'}in the GET handler itself?
There are no other routes with the same pattern, no other middleware...
Also no change is observed when I remove the options object from the second line, i.e. var router = require('express').Router();
payloadMiddleware is a generic middleware that isn't declared for any specific URL pattern containing parameters (it matches any request).
Express also doesn't know that requests passed to the middleware will eventually end up in the handler for /inventory/:itemID/price.
If you want the middleware to receive the parameters, you have to specifically use it against routes that match a pattern:
app.use('/inventory/:itemID/price', payloadMiddleware);
Or as part of the route handler:
router.get('/inventory/:itemID/price', payloadMiddleware, async function ...);
I'm using express + node.js and I have a req object, the request in the browser is /account but when I log req.path I get '/' --- not '/account'.
//auth required or redirect
app.use('/account', function(req, res, next) {
console.log(req.path);
if ( !req.session.user ) {
res.redirect('/login?ref='+req.path);
} else {
next();
}
});
req.path is / when it should be /account ??
After having a bit of a play myself, you should use:
console.log(req.originalUrl)
Here is an example expanded from the documentation, which nicely wraps all you need to know about accessing the paths/URLs in all cases with express:
app.use('/admin', function (req, res, next) { // GET 'http://www.example.com/admin/new?a=b'
console.dir(req.originalUrl) // '/admin/new?a=b' (WARNING: beware query string)
console.dir(req.baseUrl) // '/admin'
console.dir(req.path) // '/new'
console.dir(req.baseUrl + req.path) // '/admin/new' (full path without query string)
next()
})
Based on: https://expressjs.com/en/api.html#req.originalUrl
Conclusion: As c1moore's answer states, use:
var fullPath = req.baseUrl + req.path;
In some cases you should use:
req.path
This gives you the path, instead of the complete requested URL. For example, if you are only interested in which page the user requested and not all kinds of parameters the url:
/myurl.htm?allkinds&ofparameters=true
req.path will give you:
/myurl.html
UPDATE 8 YEARS LATER:
req.path was already doing exactly same thing that I mentioned here. I don't remember how this answer solved issue and accepted as a correct answer but currently it's not a valid answer. Please ignore this answer. Thanks #mhodges for mentioning this.
Original answer:
If you want to really get only "path" without querystring, you can use url library to parse and get only path part of url.
var url = require('url');
//auth required or redirect
app.use('/account', function(req, res, next) {
var path = url.parse(req.url).pathname;
if ( !req.session.user ) {
res.redirect('/login?ref='+path);
} else {
next();
}
});
This can produce different results when calling directly in base module i.e. main file (e.g. index.js or app.js) vs calling from inside module via app.use() middleware i.e. route file (e.g. routes/users.js).
API call:
http://localhost:8000/api/users/profile/123/summary?view=grid&leng=en
We'll be comparing our outputs against above API call
1) First, we'll see the result from inside module:
We'll be placing our user module inside routes directory, with one route
routes/users.js
const router = (require('express')).Router();
router.get('/profile/:id/:details', (req, res) => {
console.log(req.protocol); // http or https
console.log(req.hostname); // only hostname (abc.com, localhost, etc)
console.log(req.headers.host); // hostname with port number (if any)
console.log(req.header('host')); // <same as above>
console.log(req.route.path); // exact defined route
console.log(req.baseUrl); // base path or group prefix
console.log(req.path); // relative path except path
console.log(req.url); // relative path with query|search params
console.log(req.originalUrl); // baseURL + url
// Full URL
console.log(`${req.protocol}://${req.header('host')}${req.originalUrl}`);
res.sendStatus(200);
});
module.exports = router;
index.js
const app = (require('express'))();
const users = require('./routes/users');
app.use('/api/users', users);
const server = require('http').createServer(app);
server.listen(8000, () => console.log('server listening'));
Output
http ....................................................................................... [protocol]
localhost .............................................................................. [hostname]
localhost:8000 ..................................................................... [headers.host]
localhost:8000 ..................................................................... [header('host')]
/profile/:id/:details ........................................................ [route.path]
/api/users ............................................................................. [baseUrl]
/profile/123/summary .......................................................... [path]
/profile/123/summary?view=grid&leng=en ........................ [url]
/api/users/profile/123/summary?view=grid&leng=en ..... [originalUrl]
Full URL:
http://localhost:8000/api/users/profile/123/summary?view=grid&leng=en
2) Now, directly from main module:
We'll define our route right in the starting file (i.e. app.js or index.js)
index.js
const app = (require('express'))();
app.get('/api/users/profile/:id/:details', (req, res) => {
console.log(req.protocol); // http or https
console.log(req.hostname); // only hostname (abc.com, localhost, etc)
console.log(req.headers.host); // hostname with port number (if any)
console.log(req.header('host')); // <same as above>
console.log(req.route.path); // exact defined route
console.log(req.baseUrl); // base path or group prefix
console.log(req.path); // relative path except path
console.log(req.url); // relative path with query|search params
console.log(req.originalUrl); // baseURL + url
// Full URL
console.log(`${req.protocol}://${req.header('host')}${req.originalUrl}`);
res.sendStatus(200);
});
const server = require('http').createServer(app);
server.listen(8000, () => console.log('server listening'));
Output
http ........................................................................ [protocol]
localhost ............................................................... [hostname]
localhost:8000 ...................................................... [headers.host]
localhost:8000 ...................................................... [header('host')]
/profile/:id/:details ......................................... [route.path]
.............................................................................. [baseUrl]
/profile/123/summary ........................................... [path]
/profile/123/summary?view=grid&leng=en ......... [url]
/profile/123/summary?view=grid&leng=en ......... [originalUrl]
Full URL:
http://localhost:8000/api/users/profile/123/summary?view=grid&leng=en
We can clearly see in above output that the only difference is of baseUrl which is empty string here. So, the originalUrl also changes & looks same as the url
//auth required or redirect
app.use('/account', function(req, res, next) {
console.log(req.path);
if ( !req.session.user ) {
res.redirect('/login?ref='+req.path);
} else {
next();
}
});
req.path is / when it should be /account ??
The reason for this is that Express subtracts the path your handler function is mounted on, which is '/account' in this case.
Why do they do this?
Because it makes it easier to reuse the handler function. You can make a handler function that does different things for req.path === '/' and req.path === '/goodbye' for example:
function sendGreeting(req, res, next) {
res.send(req.path == '/goodbye' ? 'Farewell!' : 'Hello there!')
}
Then you can mount it to multiple endpoints:
app.use('/world', sendGreeting)
app.use('/aliens', sendGreeting)
Giving:
/world ==> Hello there!
/world/goodbye ==> Farewell!
/aliens ==> Hello there!
/aliens/goodbye ==> Farewell!
It should be:
req.url
express 3.1.x
For version 4.x you can now use the req.baseUrl in addition to req.path to get the full path. For example, the OP would now do something like:
//auth required or redirect
app.use('/account', function(req, res, next) {
console.log(req.baseUrl + req.path); // => /account
if(!req.session.user) {
res.redirect('/login?ref=' + encodeURIComponent(req.baseUrl + req.path)); // => /login?ref=%2Faccount
} else {
next();
}
});
req.route.path is working for me
var pool = require('../db');
module.exports.get_plants = function(req, res) {
// to run a query we can acquire a client from the pool,
// run a query on the client, and then return the client to the pool
pool.connect(function(err, client, done) {
if (err) {
return console.error('error fetching client from pool', err);
}
client.query('SELECT * FROM plants', function(err, result) {
//call `done()` to release the client back to the pool
done();
if (err) {
return console.error('error running query', err);
}
console.log('A call to route: %s', req.route.path + '\nRequest type: ' + req.method.toLowerCase());
res.json(result);
});
});
};
after executing I see the following in the console and I get perfect result
in my browser.
Express server listening on port 3000 in development mode
A call to route: /plants
Request type: get
For those getting undefined from req.route.path that is correct.
Inside route handler, there's a route.
Inside middleware handlers, there's no route.
When using a middleware in express, your request object has several properties you can use to get the correct path:
req.baseUrl: /api/account
req.originalUrl: /api/account
req._parsedUrl.path: /account
req._parsedUrl.pathname: /account
req._parsedUrl.href: /account
req._parsedUrl._raw: /account
PLEASE NOTE: This applies to middlewares