How to send headers in Express [MEAN] - javascript

I'm a beginner in Express. So I might've failed to frame the question properly. I have created a MEAN application wherein I've separated my frontend and backened. Frontend runs on port:4200 and server runs on port:3000. I wanted to run both frontend and backend on same port as part of deployment. I'm getting MIME type errors, someone told me that there is some problem with my server environment. Maybe I'm not sending headers properly. Here is my code:
I have mentioned tried solutions in the code itself as <----TRIED THIS
server.js
const express = require('express');
express.static.mime.define({'application/javascript': ['js']}); <----TRIED THIS
const bodyParser = require('body-parser');
const path = require('path');
// express.static.mime.define({'application/javascript': ['js']}); <----TRIED THIS
const api = require('./routes/api');
const PORT = 3000;
const app = express();
app.use(express.static(path.join(__dirname, 'dist')));
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.use('/api', api);
app.get('/', function(req, res) {
// res.send('Hello from the server'); <----TRIED THIS
// res.writeHead(200, {'Content-Type': 'text/html'}); <----TRIED THIS
// res.set('Content-Type', 'text/plain'); <----TRIED THIS
// res.setHeader("Content-Type","application/json"); <----TRIED THIS
res.sendFile(path.join(__dirname, 'dist/application/index.html'));
})
app.listen(PORT, function() {
console.log('Server listening on PORT '+PORT);
});
api.js
For instance I'm showing you GET function only
const express = require('express');
const router = express.Router();
const mongoose = require('mongoose');
const db = <my db string>;
const jwt = require('jsonwebtoken');
mongoose.connect(
...
)
function verifyToken(req, res, next) {
...
}
router.get('/myarticles', (req, res) => {
var person="Tanzeel Mirza";
console.log('Get request for tanzeel articles');
Article.find({contributor: person}, (error, article) => {
if(error) {
console.log(error)
}
else {
if(!article) {
res.status(401).send('Invalid email')
}
else if(2>4) {
console.log("test passed");
}
else {
res.json(article);
}
}
})
})
module.exports = router;
But still I'm getting
Loading module from “http://localhost:3000/runtime-xxx.js” was blocked because of a disallowed MIME type (“text/html”).
Loading module from “http://localhost:3000/polyfills-xxx.js” was blocked because of a disallowed MIME type (“text/html”).
Loading module from “http://localhost:3000/main-xxx.js” was blocked because of a disallowed MIME type (“text/html”).
Please correct me.
PS: I asked separate questions for MIME error here. But no answers.

Since your assets are inside dist/application folder, Use app.use(express.static(path.join(__dirname, 'dist/application')));
To match all web app routes, Use app.get('*', function(req, res) {
res.sendFile(path.join(__dirname, 'dist/application/index.html'));
}).
This a generic route and will be called into action only if express can't find any other routes and always serve index.html. For example any valid /api route will never reach this handler, as there a specific route that handles it.
Final code for server.js
const express = require('express');
const bodyParser = require('body-parser');
const path = require('path');
const api = require('./routes/api');
const PORT = 3000;
const app = express();
app.use(express.static(path.join(__dirname, 'dist/application')));
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.use('/api', api);
app.get('*', function(req, res) {
res.sendFile(path.join(__dirname, 'dist/application/index.html'));
})
app.listen(PORT, function() {
console.log('Server listening on PORT '+PORT);
});
A few points to not.
To serve static files, you need not set any headers manually. Express looks up the files in the folder (dist folder in your case) you set as static directory with the express.static middleware function. Express also sets the response headers based on the file extension.
So you don't need express.static.mime.define in your code anymore.
In your case you have defined app.use(express.static(path.join(__dirname, 'dist'))); which listens for static files at dist folder. In this app.use command, you haven't used a mount path which means that all the requests will go through the static middleware. If the middleware finds an asset with the same name, path and extension in dist folder it returns the file, else the request is passed to the other route handlers.
Also, If you are using static middleware, as long as there is an index.html in dist folder (immediate child of dist folder), your route handler for "/" will never get invoked as the response will be served by the middleware.
If you don't have an index html file in dist folder(immediate child of dist), but it's present somewhere in subfolders of dist, and still you need to access it using root path "/", only then you need a route handler for path "/" as below.
app.get("/", function(req, res) {
res.sendFile(path.join(__dirname, "dist/application/index.html"));
});
JS files referred using "./" in dist/application/index.html are referred relative to dist folder itself and NOT dist/application folder.
You can refer this REPL for updated code 👉.
https://repl.it/repls/SoreFearlessNagware
Try below urls
/api/myarticles - Rendered by "/api" route handler
/api/myarticles.js - Rendered by static asset middleware because the file exists in dist/api folder
/ - rendered using "/" route handler and res.sendFile because index.html doesn't exist in dist folder.
/test.js - Rendered using static middleware because file exists in dist folder
Additional links for reference.
https://expressjs.com/en/api.html#res.sendFile
https://expressjs.com/en/starter/static-files.html

1.Build your angular project, either inside or outside the server folder using ng build cmd.
2.To build your project inside server, change the dist-folder path in angular-cli.
3.To change path, either use cli cmd or edit the angular-cli.json file's "outDir": "./location/toYour/dist"
Or by using this cli cmd ng build --output-path=dist/example/
4.Then In your server root file include the static build/dist folder using express.
5.Like this app.use(express.static(path.join( 'your path to static folder')));
6.Now restart your server.

Related

React | React is not rendering anything in my project [duplicate]

I want to serve index.html and /media subdirectory as static files. The index file should be served both at /index.html and / URLs.
I have
web_server.use("/media", express.static(__dirname + '/media'));
web_server.use("/", express.static(__dirname));
but the second line apparently serves the entire __dirname, including all files in it (not just index.html and media), which I don't want.
I also tried
web_server.use("/", express.static(__dirname + '/index.html'));
but accessing the base URL / then leads to a request to web_server/index.html/index.html (double index.html component), which of course fails.
Any ideas?
By the way, I could find absolutely no documentation in Express on this topic (static() + its params)... frustrating. A doc link is also welcome.
If you have this setup
/app
/public/index.html
/media
Then this should get what you wanted
var express = require('express');
//var server = express.createServer();
// express.createServer() is deprecated.
var server = express(); // better instead
server.configure(function(){
server.use('/media', express.static(__dirname + '/media'));
server.use(express.static(__dirname + '/public'));
});
server.listen(3000);
The trick is leaving this line as last fallback
server.use(express.static(__dirname + '/public'));
As for documentation, since Express uses connect middleware, I found it easier to just look at the connect source code directly.
For example this line shows that index.html is supported
https://github.com/senchalabs/connect/blob/2.3.3/lib/middleware/static.js#L140
In the newest version of express the "createServer" is deprecated. This example works for me:
var express = require('express');
var app = express();
var path = require('path');
//app.use(express.static(__dirname)); // Current directory is root
app.use(express.static(path.join(__dirname, 'public'))); // "public" off of current is root
app.listen(80);
console.log('Listening on port 80');
express.static() expects the first parameter to be a path of a directory, not a filename. I would suggest creating another subdirectory to contain your index.html and use that.
Serving static files in Express documentation, or more detailed serve-static documentation, including the default behavior of serving index.html:
By default this module will send “index.html” files in response to a request on a directory. To disable this set false or to supply a new index pass a string or an array in preferred order.
res.sendFile & express.static both will work for this
var express = require('express');
var app = express();
var path = require('path');
var public = path.join(__dirname, 'public');
// viewed at http://localhost:8080
app.get('/', function(req, res) {
res.sendFile(path.join(public, 'index.html'));
});
app.use('/', express.static(public));
app.listen(8080);
Where public is the folder in which the client side code is
As suggested by #ATOzTOA and clarified by #Vozzie, path.join takes the paths to join as arguments, the + passes a single argument to path.
const path = require('path');
const express = require('express');
const app = new express();
app.use(express.static('/media'));
app.get('/', (req, res) => {
res.sendFile(path.resolve(__dirname, 'media/page/', 'index.html'));
});
app.listen(4000, () => {
console.log('App listening on port 4000')
})
If you have a complicated folder structure, such as
- application
- assets
- images
- profile.jpg
- web
- server
- index.js
If you want to serve assets/images from index.js
app.use('/images', express.static(path.join(__dirname, '..', 'assets', 'images')))
To view from your browser
http://localhost:4000/images/profile.jpg
If you need more clarification comment, I'll elaborate.
use below inside your app.js
app.use(express.static('folderName'));
(folderName is folder which has files) - remember these assets are accessed direct through server path (i.e. http://localhost:3000/abc.png (where as abc.png is inside folderName folder)
npm install serve-index
var express = require('express')
var serveIndex = require('serve-index')
var path = require('path')
var serveStatic = require('serve-static')
var app = express()
var port = process.env.PORT || 3000;
/**for files */
app.use(serveStatic(path.join(__dirname, 'public')));
/**for directory */
app.use('/', express.static('public'), serveIndex('public', {'icons': true}))
// Listen
app.listen(port, function () {
console.log('listening on port:',+ port );
})
I would add something that is on the express docs, and it's sometimes misread in tutorials or others.
app.use(mountpoint, middleware)
mountpoint is a virtual path, it is not in the filesystem (even if it actually exists). The mountpoint for the middleware is the app.js folder.
Now
app.use('/static', express.static('public')`
will send files with path /static/hell/meow/a.js to /public/hell/meow/a.js
This is the error in my case when I provide links to HTML files.
before:
<link rel="stylesheet" href="/public/style.css">
After:
<link rel="stylesheet" href="/style.css">
I just removed the static directory path from the link and the error is gone. This solves my error one thing more don't forget to put this line where you are creating the server.
var path = require('path');
app.use(serveStatic(path.join(__dirname, 'public')));
You can achieve this by just passing the second parameter express.static() method to specify index files in the folder
const express = require('express');
const app = new express();
app.use(express.static('/media'), { index: 'whatever.html' })

How do I serve an HTML file in Express from a directory which is a level above my server folder?

I am trying to serve an HTML file which is in my main directory, through my Express server which is one level deeper: in my server folder. This is how the server code is set up:
const express = require('express');
const app = express();
app.use(express.json());
app.get('/', (req, res) => {
res.sendFile(__dirname + '/index.html');
})
const port = 5000;
app.listen(port, () => console.log(`Server is listening on port ${port}.`))
The error I am receiving is:
Error: ENOENT: no such file or directory, stat '/mnt/c/Project-Directory/server/index.html'
It is clear from this error why I am not able to access my HTML file; my server exists in the /server folder and my index.html file exists in the Project-Directory folder. However, I am not sure how to access my HTML file in its current directory.
You can use path.join and specify that you want one directory back (../):
const path = require('path');
app.get('/', (req, res) => {
res.sendFile(path.join(__dirname, '../index.html'));
})

Express server don't search static files in Angular 12 app

Background
I am migrating an Angular app in GKE cluster. The base docker image that I must use(company policy) does not have any options to install any new softwares like shell, Angular cli command ng etc. The base docker image has only Node installed.
There is a shared base url, let's say, www.my-company.com, that everyone has to use for app deployment with a path added after the base url like www.my-company.com/my-angular-app/ - all the other Angular apps must be differentiated using the path of the app.
What I did
Since I can't run ng serve command in the base image, I added Express dependency in the package.json in Angular application and created an express server to route the traffic to Angular app.
I was following this youtube video to configure the application - https://www.youtube.com/watch?v=sTbQphoYbK0&t=303s. The problem I am facing is to how I load the the static files in the application.
If I define absolute path inside sendFile method of server.js file, although the application is working, but in future, if I need to add any other files in the application, I have to create another route in server.js file.
I don't know how Express can search a file automatically from the static folder(and sub folders) and return only that file when needed. I defined a static folder too, but seems like it is not working.
Following is my server.js code
==============================
const express = require('express');
const http = require('http');
const path = require('path');
const port = 8080;
const contextPath = '/my-angular-app';
const router = express.Router();
const app = express();
app.use(contextPath, router);
app.listen(port, ()=> {
console.log("Listening on port: ", port);
});
app.use(express.static(__dirname + '/dist/testapp/'));
router.get('/', function(req, res) {
// to get index.html file
res.sendFile(path.resolve(__dirname + '/dist/testapp/index.html'));
});
router.get('/*', function(req, res) {
let path = __dirname +'/dist/testapp/' + req.path
console.log('full path: ', path);
// To return static files based on incoming request, I am facing problem here(I think)
res.sendFile(path);
});
==============================
I want Express will send any files based on file name in the request. It should also take care of nested directories in the /dist/testapp/ directory
/dist/testapp/ -> This is the directory where Angular generates code for my app after I execute ng build command
WEBAPP.get("/admin/script.js", (req, res) => {
console.log(req.path);
if (req.session.username !== "Admin") return res.render("error");
res.sendFile(__dirname + "/admin/admin.js")
});
WEBAPP.get("/admin", (req, res) => {
if (!req.session.loggedin) return res.render("error");
if (req.session.username !== "Admin") return res.render("error",);
res.render("admin", {
csrfToken: req.csrfToken(),
title: "ADMIN PORTAL",
username: req.session.username,
nav_avatar: GetImageURL(req.session.avatar, "small")
});
});
There's no need to publically share /admin/script.js in my case but if a user requests this URL say example.com/admin/script.js a check for username equaling "Admin" if all is okay we sendFile.
I would maybe assume that you're not properly targeting your static files. Perhaps console.log the target.

Serving css with express js

I have been having a lot of trouble with serving css using express js. I finally figured out how, but I'm a bit confused why my new code works, but my old code doesn't. This is my new code that does work:
const express = require('express');
const path = require('path');
const app = express();
const port = process.env.PORT || 5010;
console.log(__dirname)
app.use('/public', express.static('public'));
app.set('views', path.join(__dirname, 'views'))
app.get('/', (req, res) => {
res.sendFile(path.join(__dirname, 'views', 'home.html'));
});
app.listen(port, () => {
console.log(`Server started on port ${port}`);
});
My file system looks like this:
index.js
public
css
home.css
views
home.html
Originally instead of having:
app.use('/public', express.static('public'));
I had:
app.use(express.static(path.join(__dirname, 'public')));
Why does the second version work, but the first one doesn't? What is the purpose of the first parameter in the second version? Also, just in case it makes a difference, I'm coding on replit.com.
When using 1 parameter
app.use(express.static(path.join(__dirname, 'public')));
This code serve files in the "public" subdirectory of the current directory. The URL to access the file at public/css/home.css is : http://localhost/css/home.css
When using 2 parameters
app.use('/public', express.static('public'));
This code also serve files in the "public" subdirectory of the current directory, with a virtual path prefix "/public". So, the URL to access the file at public/css/home.css is : http://localhost/public/css/home.css
We can change the first parameter to anything, for example, if we have :
app.use('/static', express.static('public'));
Then the URL to the same file becomes : http://localhost/static/css/home.css.
You can find more information from the official document here

node how can My app find index.js

Folder structure
bin - www.js
lib - jsFiles...
models - jsFiles...
node_modules -Folders and Files
public - index.html
route - jsFiles...
index.js
package.json
I use Express, angular.js. Server starts at www.js and It calls
index.js. After that, When I type merely "localhost:3000" It shows me
public/index.html. I don't have route for '/' but It shows me
'public/index.html'. I can not understand this. Please let me know
about the process.
www.js
var debug = require('debug')('example-server');
var app = require(process.cwd()+'/index');
//listen at 3000 port
app.set('port',process.env.PORT || 3000);
var server = app.listen(app.get('port'),function()
{
debug('Express server listening on port ' + server.address().port);
});
index.js
var favicon = require('serve-favicon');
var express = require('express');
var path = require('path');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
//Connection for DB
require('./lib/connection');
var employees = require('./routes/employees');
var teams = require('./routes/teams');
var app = express();
// Writing at routing table
app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended:true }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname,'public')));
app.use(employees);
app.use(teams);
// send 404 to errorhandler
app.use(function(err,req,res,next)
{
var err = new Error('Not Found');
err.status = 404;
console.log(error);
next(error);
});
...
...
module.exports = app;
In express.js the sequence in which you register your middleware makes a huge difference.
When express.js receives a request, it starts from top and executes registered middleware.
Middlewares are registered in express app using app.use(middleware_goes_here) this type of middleware gets executed no matter what the request url is on the other hand you can also register a middleware like app.use('/url/path',middleware_goes_here) in this case we are registering this middleware to '/url/path' so this middleware will only get executed when you visit '/url/path' (and non of the previous matching middleware serves the request without calling next() )
This app.use(express.static(path.join(__dirname,'public'))); line of code does the magic.
You can go here (express.static ref) to know more about static content serving and routing.
Basically what happens is, we are configuring express.static middleware to serve static content "as is" from "public" folder. So when you make any request and it matches a static content in public folder, then it will serve it otherwise express.static will call next middleware in sequence.
So in your case, the first middleware that actually server input request is express.static without any route filters, so it servers index.html even without a specifically defined route. If your public folder had file at public/javascript/jquery.js then following url will map to it http://localhost:3000/javascript/jquery.js
NOTE: You do not have to specify "public" in the url, the way in which express.static is registered, it will server contents FROM "public" folder.
................
UPDATE: How does default work in express.static?
By default, app.use(express.static(path.join(__dirname,'public'))); this will take index.html as default document. If you want to set index2.html as your default document, you can do that by doing something like this app.use(express.static(path.join(__dirname,'public'),{index: 'index2.html'}));
Hope it helps.
Put a relative path to folder(one up in hierarchy).
var app = require('../index');

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