What does a '*' mean as a route in app.get()? - node.js

I am deploying a PERN (PostgreSQL, Express, React, Node) on Heroku. I watched a tutorial on YouTube and he has some kind of this code for deploying to production:
if (process.env.NODE_ENV == "production") {
const path = require("path");
app.use(express.static(path.join(__dirname, "./build")));
app.get("*", (req, res) => {
res.sendFile(path.join(__dirname, "build", "index.html"));
});
}
So I want to ask what does the * route mean in app.get(...) does it work same with the path / route or something else?

Here * is a wild card. This means this router will handle not just /, but any request that starts with / - be it /about, /products, or even /product-details. That * (wildcard) stands for "any route path can be here", whatever link you'll access through a GET request, will trigger that middleware

Related

express route and react route have conflict - it is returning api result on heroku

first of all it's working proper in my local but it works the way i don't want on heroku.
I working on a MERN stack app and I have express path same time react router path.
https://test.herokuapp.com/project
in my node.js express side
server.js
--------
/* Router */
import routes from "./routes/index.js"
app.use('/', routes)
/* For Deployment */
if(process.env.NODE_ENV === "production") {
app.use(express.static(path.join(__dirname, './../client/build')))
app.get('*', (req, res) => {
res.sendFile(path.resolve(__dirname, "../client/build/index.html"));
})
}
routes/index.js (it returns project data from mongodb)
---------------
router.get( '/project', ProjectController.getAll);
at the same time i have a another route in my react side
const routers = (isUserAuth, isAdminAuth) => [
{
path: '/project',
exact: true,
element: <Project />
}
]
http://localhost:3000/project
that route when react router redirect with a NavLink working and if page refresh manually still working in my local. But when it comes to heroku platform it's working redirect with NavLink but it doesn't work when refresh the page. When refresh the page as i said it returns project data from express serve nodejs side.
I think it's about the first code block I put above. thanks..

bodyParser middleware not working when adding static route

I'm a newbie on express, and when I was creating a simple server demo I detected that POST requests were not sent. After doing some experiments I discovered that it was the express.static middleware, that somehow was interfering. I supposed it was a common error, but didn't manage to find a clue. My code is the following:
//jshint esversion:6
import express from "express";
import path from "path";
import { fileURLToPath } from "url";
import bodyParser from "body-parser";
import https from "https";
/* jshint ignore:start */
const __filename = fileURLToPath(import.meta.url);
/* jshint ignore:end */
const __dirname = path.dirname(__filename);
const app = express();
const port = 8080;
app.use(express.static(__dirname + "/public"));
app.use("/", bodyParser.urlencoded({ extended: true }));
app.get("/", (req, res) => {
res.sendFile(__dirname + "/index.html");
});
app.post("/", function (req, res) {
let name = req.body.name;
let email = req.body.email;
let message = req.body.message;
res.send("POST request to the homepage");
console.log(req.body);
});
app.listen(port, () => console.log(`Listening on port ${port}!`));
I'll gladly appreciate any answer or commet :)
EDIT: Apparently this error doesn't occur on Firefox, but does on Chrome and Edge
Based on your symptoms of the POST not even being sent from the client when you added the express.static(), I would guess that when you go to the / route in your browser, that express.static() was picking up an index.html from your public directory rather than the index.html that you wanted from here:
app.get("/", (req, res) => {
res.sendFile(__dirname + "/index.html");
});
You can fix that two ways. Either move this app.get("/", ...) route before the express.static() route or tell the express.static route to NOT serve index.html like this:
// set up static file handling, but don't serve index.html for the / request
app.use(express.static(__dirname + "/public", {index: false}));
Ok figured out what was really blocking this.
When adding express.static() it loaded the JS for the front-end, which has the following line:
$(".sendMessageBtn").attr("disabled", "true");
which disables the submit button. Turns out disabling it also means it can't send anything BUT only on chromium browsers. This does not happen on Firefox.
To disable it without causing this mess, you can replace with:
$(".sendMessageBtn").css("pointer-events", "none");
Instead of disabling it through HTML, it uses CSS
So the way express static file serving works is that you put a /path which you want to serve on, and the term express.static(/path/to/static/folder) which will be published to the api.
Otherwise your entire application will be static, due to the fact that everything start with /.
See the docs for more info.
In your case:
app.use("/your-static-endpoint", express.static(__dirname + "/public"));
One more thing about your code. Stuff like static serving, error handling, body parsing are called middlewares, so if you want to apply them through the application, you shouldn't specify a path, because it might interfere with how express handles routing.

Prevent Angular 6 router from overriding routes defined in Express Server

How do I prevent Angular routing from interferring with routes from an Express Node Server?
I'm setting up some routes ( to node-RED middleware) in my Express server:
server.js
// Serve the editor UI from /red
app.use(settings.httpAdminRoot,RED.httpAdmin);
// Serve the http nodes UI from /api
app.use(settings.httpNodeRoot,RED.httpNode);
// Angular DIST output folder
app.use(express.static(path.join(__dirname, 'dist')));
// Send all other requests to the Angular app
app.get('*', (req, res) => {
res.sendFile(path.join(__dirname, 'dist/index.js'));
});
but in my router module they get always overridden ( with our without the default path redirection)
routing.module.ts
const appRoutes: Routes = [
{
path: "example-page",
loadChildren: "../modules/example/example.module#ExampleModule?sync=true"
},
// Last routing path specifies default path for application entry
/* {
path: "**",
redirectTo: "/example-page",
pathMatch: "full"
},*/
];
I'm only providing this little code because I want to ask in general how do I prevent Angular from interferring with routes defined in an Express server and what is the best practice for routing in an Express/ Node.js + Angular + AspNetCore + Webpack app.
If you're using Angular, then let Angular handle all pages. This code takes care of that and hence angular is handling all routes.
app.get('*', (req, res) => {
res.sendFile(path.join(__dirname, 'dist/index.js'));
});
If you want express to handle some routes instead of angular, handle that route before handling angular route as follows:
app.get('/some-non-angular-path', (req, res) => {
//code to handle this path. once it is handled here, angular won't be involved
//non-angular-paths should come first in the order
});
app.get((req, res) => {
res.sendFile(path.join(__dirname, 'dist/index.js'));
});

Serving multiple react apps with client-side routing in Express

I have different software products for one single service, which needs to be deployed to a single server. The clients are built with react, with a build setup by create-react-app, while the server runs Node.js and Express.
When I serve a single application from the server it is done the following way:
// App.js
// ...
// Entry point for data routes (API)
app.use('/data', indexRoute);
if(process.env.NODE_ENV !== 'development') {
app.use(express.static(path.join(__dirname, 'build-client')));
app.get('/*', function(req, res) {
return res.sendFile(path.resolve( __dirname, 'build-client' , 'index.html'));
});
}
I want to be able to serve multiple apps from the server. How should I do that?
What I tried is to wire in different static paths for the assets and separate the clients with different names, although it did not work. Like this:
// App.js
// ...
// Entry point for data routes (API)
app.use('/data', indexRoute);
if(process.env.NODE_ENV !== 'development') {
app.use(express.static(path.join(__dirname, 'build-client')));
app.use(express.static(path.join(__dirname, 'build-admin')));
app.get('/client/*', function(req, res) {
return res.sendFile(path.resolve( __dirname, 'build-client' , 'index.html'));
});
app.get('/admin/*', function(req, res) {
return res.sendFile(path.resolve( __dirname, 'build-client' , 'index.html'));
});
}
I have also tried to do it this way, but Express throw Error: No default engine was specified and no extension was provided:
if(process.env.NODE_ENV !== 'development') {
// Admin paths
app.use('/admin', express.static(path.join(__dirname, 'build-admin')));
app.get('/admin/*', function(req, res) {
return res.sendFile(path.resolve( __dirname, 'build-admin' , 'index.html'));
});
// Site paths
app.use('/', express.static(path.join(__dirname, 'build-client')));
app.get('/*', function(req, res) {
return res.sendFile(path.resolve( __dirname, 'build-client' , 'index.html'));
});
}
How could I accomplish this or something similar?
After some tinkering I was able to achieve this without using virtual hosts. I used the first idea you gave in the question, except I left the main app at the root (i.e. /).
// when going to `/app2`, serve the files at app2/build/* as static files
app.use('/app2', express.static(path.join(__dirname, 'app2/build')))
// when going to `/`, serve the files at mainApp/build/* as static files
app.use(express.static(path.join(__dirname, 'mainApp/build')))
// These are necessary for routing within react
app.get('app2/*', (req, res) => {
res.sendFile(path.join(__dirname + '/app2/build/index.html'))
})
app.get('*', (req, res) => {
res.sendFile(path.join(__dirname + '/mainApp/build/index.html'));
});
After this, I went into mainApp/package.json and added
"proxy": "http://localhost:4141"
:4141 is the port that the express server is running on. This line will make calls to fetch('/some/route') go back to the server instead of into your react app itself.
Finally, we go to app2/package.json and add
"proxy": "http://localhost:4141/app2",
"homepage": "/app2"
I believe that the key here is the "homepage" key. The way I understand it, when react starts it searches for some static files at its homepage, and without the "homepage" piece I was only able to get either a blank white screen or the mainApp.
I hope this helps someone out there!
EDIT
I have since changed from serving my create-react-apps through my express server to serving them through netlify. Now I don't need to worry about this express setup, or the homepage key in package.json. The express server lives by itself, and the react apps can still both use the same api, and deployment is much easier. Setup with netlify is trivial.
After struggling for a while with this problem I've found a possible solution without compromising the original setup.
We used Express vhost package to setup handling of requests through virtual domains.
When you create your app instance, you should initialize as many apps with express as you want to expose separately (in our case its three separate apps plus the original app instance)
// Create an express instance
const app = express();
const appAdmin = express();
const appClient = express();
const appVendor = express();
After that you need to install vhost and import it. Then with specifying the static folder for each app you can handle serving the static files separately, while the remaining part deals with handling the request for the given subdomains respectively.
appAdmin.use(express.static(path.join(__dirname, 'build-admin')));
appClient.use(express.static(path.join(__dirname, 'build-client')));
appVendor.use(express.static(path.join(__dirname, 'build-vendor')));
appAdmin.use((req, res, next) => {
return res.sendFile(path.resolve( __dirname, 'build-admin' , 'index.html'));
});
appClient.use((req, res, next) => {
return res.sendFile(path.resolve( __dirname, 'build-client' , 'index.html'));
});
appVendor.use((req, res, next) => {
return res.sendFile(path.resolve( __dirname, 'build-vendor' , 'index.html'));
});
app.use(vhost('domain.com', appClient));
app.use(vhost('www.domain.com', appClient));
app.use(vhost('a.domain.com', appAdmin));
app.use(vhost('b.domain.com', appVendor));
Don't forget to add the desired subdomains in your domain's DNS registry. Example:
...records
CNAME vendor #
CNAME admin #

Intercept request for a static file in express.js

I have a node server, that serves static files in a PUBLIC folder like this:
var app = express();
app.listen(port);
app.use(compression());
app.use(express.static(__dirname + '/PUBLIC'));
There is a json file, let's say important.json that is located in /PUBLIC folder. This is being served as a static file
Now, I want to intercept request for this /PUBLIC/important.json, so that I can programatically return a random json structure instead.
None of the followings works:
app.get('/PUBLIC/important.json', function(req, res) {
console.log("caught1!")
});
app.get(__dirname + '/PUBLIC/important.json', function(req, res) {
console.log("caught2!")
});
app.get('important.json', function(req, res) {
console.log("caught3!")
});
How can I intercept request for that partically static file?
As the express.static middleware does not call the next middleware using next(), the definition order is important. You have to define your own middleware before using express.static.
app.get('/PUBLIC/important.json', (req, res, next) => {
console.log('caught');
next();
});
app.use(express.static(__dirname + '/PUBLIC'));
Could you tell us a bit more about your stack ?
Are you using nginx / apache to proxy_pass the traffic to your nodejs server ?
Are you just running your app with "node app.js"
Let's try to add this simple route in your application :
app.get('/', function (req, res) {
res.send('Hello World!');
});
And try to access it by removing URI parameters ? Does the "Hello world" show up ?
I just want to be sure the traffic is actually treated by your node app.
Your route definition is supposed to work for your actual request.

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