I have a Node.js server. Lets say each client has his name saved on a variable. They switch page and I want each client to mantain their name on a variable.
This would be very easy with a php form, but I can't see how to do it with Node.js
If I do a form like I would do in php, I manage to send the name to the server:
app.post('/game.html', function(req, res){
var user = req.param('name');
console.log(user);
res.redirect('/game.html');
});
But it seems too complicated to then resend it again to each client it's own.
I just started with Node.js, I guess it's a concept error. Is there any easy way to pass a variable from one page in the client to another?
Thanks.
Instead of redirecting to a static file, you have to render the template ( using any engine that ExpressJS supports ):
app.post('/game.html', function(req, res){
var user = req.param('name');
console.log(user);
res.render( 'game.html', { user:user } );
});
( note that .render requires some additonal settings set on app )
Now user variable becomes available in game.html template.
You can use res.render and pass many variables, like that:
res.render('yourPage', {username:username, age:age, phone:phone});
Related
I'm reading the Express framework docs, making my basic login/redirect page routes.
The following route accepts the submission:
app.post('/',function(req,res){
//console.log("USERNAME: "+req.body.username);
//console.log("PASSWORD: "+req.body.password);
res.redirect('/chat');
});
and this:
app.get('/chat', function(req, res){
res.sendFile(__dirname + '/templates/chat.html');
//console.log("request");
});
takes the user to a new page.
How do I send context? Should I be using res.render()? Neither function seems to contain an option for data like {username:req.body.username}. How should data be passed between routes?
Generally to handle logins with express you'd use something like passport's local strategy, which attaches a user object to the request object (req.user) for you for each route. I don't know that what you're trying will work in a larger context -- you'd need some kind of session-based middleware like express-session at the very least, so you can attach variables per session (I think it gives you req.session). By default, express has the capability to store information for one request/response cycle (res.locals) or for the entire instance of the app (i.e. for all users) (app.locals).
As far as getting data into views, you would use res.render with something like EJS, pug, or another view engine. For example, if in your route, you had something like:
route.get('/', (req, res) => {
res.render('template', { username: 'yourname' })
}
you can refer to that in your ejs template like so:
<h1>Hello, <%= username %>!</h1>
which will get sent back as this:
<h1>Hello, yourname!</h1>
So, to answer your question:
You would use res.render to get variables & data into your views
You don't share data across routes by default except app-level data that applies to all users, which can be set on app.locals
You can use authentication middleware like passport and session middleware like express-session to keep track of user information across routes per session.
Hope this helps! Good luck with express!
I want to extend this open topic: Add Routes at Runtime (ExpressJs) which sadly didn't help me enough.
I'm working on an application that allows the creation of different API's that runs on NodeJs. The UI looks like this:
As you can see, this piece of code contains two endpoints (GET, POST) and as soon as I press "Save", it creates a .js file located in a path where the Nodejs application is looking for its endpoints (e.g: myProject\dynamicRoutes\rule_test.js).
The problem that I have is that being that the Nodejs server is running while I'm developing the code, I'm not able to invoke these new endpoints unless I restart the server once again (and ExpressJs detects the file).
Is there a way to register new routes while the
NodeJs (ExpressJs) is running?
I tried to do the following things with no luck:
app.js
This works if the server is restarted. I tried to include this library (express-dynamic-router, but not working at runtime.)
//this is dynamic routing function
function handleDynamicRoutes(req,res,next) {
var path = req.path; //http://localhost:8080/api/rule_test
//LoadModules(path)
var controllerPath = path.replace("/api/", "./dynamicRoutes/");
var dynamicController = require(controllerPath);
dynamicRouter.index(dynamicController[req.method]).register(app);
dynamicController[req.method] = function(req, res) {
//invocation
}
next();
}
app.all('*', handleDynamicRoutes);
Finally, I readed this article (#NodeJS / #ExpressJS: Adding routes dynamically at runtime), but I couldn't figure out how this can help me.
I believe that this could be possible somehow, but I feel a bit lost. Anyone knows how can I achieve this? I'm getting a CANNOT GET error, after each file creation.
Disclaimer: please know that it is considered as bad design in terms of stability and security to allow the user or even administrator to inject executable code via web forms. Treat this thread as academic discussion and don't use this code in production!
Look at this simple example which adds new route in runtime:
app.get('/subpage', (req, res) => res.send('Hello subpage'))
So basically new route is being registered when app.get is called, no need to walk through routes directory.
All you need to do is simply load your newly created module and pass your app to module.exports function to register new routes. I guess this one-liner should work just fine (not tested):
require('path/to/new/module')(app)
Is req.params enough for you?
app.get('/basebath/:path, (req,res) => {
const content = require('content/' + req.params.path);
res.send(content);
});
So the user can enter whatever after /basepath, for example
http://www.mywebsite.com/basepath/bergur
The router would then try to get the file content/bergur.js
and send it's contents.
So what I'm trying to do is when someone loads my site, and gets authenticated by passport, their userId is stored in req.user.id in my app.get('/home', funciton(req, res). Now what I am trying to do in a way is this:
app.get('/home'. function(req, res){
io.on('connection', function(socket){
socket.emit('userId', req.user.id);
});
}
Thats essentially what I'm trying to do, but I know it is very wrong. Now my question is how can I get the req.user.id to the client so I can use it in future interactions with the server.
Looks like you're receiving a GET request and using Express right? You're probably passing the userid in the querystring, so you'll want to use:
req.query.userid
This basically pulls the value assigned to a key in the querystring.
Source: http://expressjs.com/en/api.html#req.query
I would also recommend sending something like ?userid=12345 in the querystring, rather than an object (user.id) in the querystring, as encoding an object will unnecessarily add more complications and not needed.
You can use express session with socket.io
There's a npm module called express-socket.io-session
I want to do a re-direction from one nodejs file to another nodejs file. I used res.redirect(URL), but when execute it says "cannot GET /nodepage"
Currently I am using
// Handler for GET /
app.get('/nodepostgres', function(req, res){
res.redirect('/nodepost.js?a=1');
});
I think there are a few things that you don't explain properly or don't understand properly in your question.
I am not sure what you mean about "re-direction from one nodejs file to another nodejs file". You seems to think that a node script file correspond to a URL (or a page). That's wrong. A node script correspond to an application that may (or may not) expose several pages through several URL and can imports application logic from other script files (you will run a single root script file for a site or application). It's totally different from what you may know with (vannilla, no framework) PHP.
Exposing different pages through different url is called Routing, all Express documentation about routing can be found here.
What I understand is that your trying to make a function / page / Url per script : nodepost.js file is a page. Code organization is a good thing but let's focus on how node + express works first.
From what I understand, you're applicaton has a few exposed url, let's say :
"/" homepage
"/nodepostgre" (maybe accepting an 'a' arg ?)
"/nodepost" accepting an arg : a
Note : we forget the id of file = page, we don't want an extension to appear on URL so nodepost.js becomes nodepost
What you can do is setup the 3 url expositions :
app.get('/', function(req, res) { res.render('home'); }); // render the home page
app.get('/nodepost', function(req, res) { // expose the nodepost function
var a = req.params.a;
doSomethingWith(a);
// res.render, res.send ? whatever you want...
]);
app.get('/nodepostgres', function(req, res){ // use of res.redirect(url[, status])
res.redirect('/nodepost');
});
Is that what you want ?
Then, here is a more elegant way to handle params ("a").
app.get('/notepost/:a', function(req, res) { // called via /nodepost/here_goes_a_valu ; no "?"
var a = req.params.a;
});
Why is it better ?
Respect REST (may not be the best link to describe rest but...)
Allows you to expose '/nodepost' without params
Certainly one million other things
I'm using Node.js and Express, and I want to pass a local variable in to the layout on every page, is there any way to do this? I'm using Jade as my templating engine.
The reason I want this is because I want to display the user's username on every page (using session), any way to do this other than including it every time in the local object?
You can achieve this by defining a dynamic view helper, as pointed out in the official Express guide:
app.dynamicHelpers({
session: function(req, res){
return req.session;
}
});
Then in your views you can simply access the session variable, and for example session.user to display the user.