Develop Reference

ExpressJS + JWT. What's the proper way to get auth data?

Let's jump to an example. I'll skip some parts like imports, exports.
I have a controller called controllers/book.js with one route:
router.get('/my-books', function(req, res) {
if(Auth.authenticated(req,res)) {
Book.getMyBooks(function(rows) {
response.operationSucceed(req, res, rows);
});
}
});
Then, in a model called models/book.js I have that function:
function getMyBooks(successCallback) {
db.query('SELECT * FROM book b WHERE b.id_user=?', [Auth.getLoggedUID()], function(rows) {
successCallback(rows);
});
}
My question is about Auth.getLoggedUID function.
Assuming that I have a JWT authentication and assuming that I have an UID in payload (is that even acceptable?), what's the best option to retrieve it? Is there any, EXCEPT passing the req every time to every function where I need auth data?
I may have a function execution inside a function, do I need to pass the req through both of them to get the user ID? Like this?:
function getBooks(req) {
getMyBooks(req);
getCriminalBooks(req);
getEvenOtherBooksByAuthor(req, authorId);
}
Honestly I wouldn't like that.
Maybe my whole concept is wrong and I should be doing things differently?
Can someone point me the right direction in scenarios like this?

You can pass UID in header and retrieve it inside your controller as:
var uid =req.header('UID');
Then pass this UID where ever you want there is no need to carryforward whole req object everywhere.

You can use a middleware function. Let's say that every request that hits your endpoints, will have a token which you should check and possibly decode it. After that, you can set the decoded content to the req object. So something like this:
app.use(function(req, res, next) {
// get the token from the request headers most likely.
// verify and decode the token
// set the decoded content to the request
var payload = ..
req.payload = payload;
});
After this you can access the payload in every single endpoint you have. So for example in some controller you can do:
app.get('/hey', function(req, res) {
var payload = req.payload;
});

How to create a global function which will access DB in express.js

I use express.js, mongodb, ejs. In the navbar, there's an email icon and will display the count of new emails.
<%=newEmailCount%>
Then I need to add this newEmailCount to every route.
Emails.count({userId: userId, new: true})
my question is in express.js, how can I add a global function that can be executed by every route?

If you want to get the count for every GET requests then you can use following approach
router.get('*', function(req, res, next) {
res.locals.newEmailCount = Emails.count({userId: userId, new: true})
next();
})
You need to make sure this is always executed by placing it above all the other routes.
You can then pass res.locals.newEmailCount to your render function which renders HTML file for matched route.
This will work also for application instance level routes handling if that's what you're using.

Dynamic routing in Node.js

I want to create dynamic stubs as webservices. My idea is to load at every request a definition file and return data for corresponding URL.
The definition file could look like this:
/api/users {users:["john", "jack", "jake"]}
/api/users/1 {user:"john"}
/api/some-data/1 {data:"some data"}
In an application I created on behalf of a tutorial I find:
router.post('/some-irl', function (req, res) {
//some code
return {some JSON}
});
But this definition looks static to me, which should be there before I start Node.js Is it possible to define /some-irl at the time then request occures?
EDIT
Actually, I was intending to do somehting like this: https://github.com/typicode/json-server but it is already there!

You can attach a use middleware, which can check the path and decide whether to handle it or pass it on:
router.use(function(req, res, next) {
// req.path
// decide what to do
// respond or next()
});

you can define variables in the routes, use : before the variable name to define it, and then you'll get the value in req.params:
route.get('/api/users/:user/', function (req, res) {
var username = req.params.user;
});

Express Routes & Controllers

I understand that out of the box Express isn't an MVC framework, however I'm trying to set it up like one.
I've used other similar frameworks in PHP like Laravel where in a route in you can use a controller like
Route::get('user/profile', 'UserController#showProfile');
Which will run all the code in the showProfile method in the UserController class,
so my question is, how would I achieve the same thing or something similar using Express?
I'm using Node 5 and writing the code in ECMAScript 6.
Currently I have a class I want to use as the controller and a method I want to return the data, I'm able to log the data to the console when a user navigates to the route but haven't figured out how to send it back as the response.

If you dive into the documentation, you'll find that the "controller methods" you refer to need to conform to a specific signature. Namely, they receive (at least) the request and response representations.
If you have already created a router, this will be a rough equivalent to the PHP you posted:
router.get('user/profile', userController.showProfile)
Your showProfile "method" needs to have this signature:
const userController = {
showProfile(req, res) { /*...*/}
}
I put "method" in quotes because express won't call it as a method unless you explicitly bind it to the controller object. We're passing it as an unbound function here. If you wanted to use it as a method (to have access to the controller as this), pass userController.showProfile.bind(userController) to router.get†.
But for now let's stick to those req and res parameters of the showProfile handler (that's the proper name). req represents the HTTP request, you can get headers, request payload and other stuff from it. res is the HTTP response that will be sent. So you can use it to set an HTTP status code, send body data and so on.
For illustrative purposes, let's assume you can get your user profile synchronously by calling userController.getProfile(id). And let's assume that, by some mechanism, a property userId is set on the request that is the currently authenticated user's ID.
const userController = {
showProfile(req, res) {
// We call some code to get what we want to send back
const profile = userController.getProfile(req.userId)
// We send it in the response as JSON
res.send(profile)
}
}
res.json will JSON.stringify the profile and send it as response payload.
How do you get req.userId set, you ask? Well, this is just an example, but you can achieve similar results by using middleware. A middleware is simply a handler that does something and then lets other handlers continue processing the request. But again, there's plenty to read from the docs.
† It's usually not necessary though, since controllers tend to be singletons. You can simply access its properties by doing userController.otherProperty. Of course, you don't even need to define a handler as a method of a controller object, it can be a function that stands on its own.

I did something like this
usercontroller.js
class UserController() {
constructor() {
this.users = ['user1', 'user2'];
}
getUsers(req, res) {
res.status(200).json(this.users);
}
}
//router.js
const port = 3000;
const app = express();
const _invoke = function(controller) {
return function(req, res) {
const [controllerClass, method] = controller.split('#')
const className = require(controllerClass)
const obj = new className
obj[method](req, res)
}
}
app.get('/get-users',
_invoke('./controllers/UserController#getUsers'));
app.listen(port);

Using the PUT method with Express.js

I'm trying to implement update functionality to an Express.js app, and I'd like to use a PUT request to send the new data, but I keep getting errors using PUT. From everything I've read, it's just a matter of using app.put, but that isn't working. I've got the following in my routes file:
send = function(req, res) {
req.send(res.locals.content);
};
app.put('/api/:company', function(res,req) {
res.send('this is an update');
}, send);
When I use postman to make a PUT request, I get a "cannot PUT /api/petshop" as an error. I don't understand why I can't PUT, or what's going wrong.

You may be lacking the actual update function. You have the put path returning the result back to the client but missing the part when you tell the database to update the data.
If you're using MongoDB and ExpressJS, you could write something like this :
app.put('/api/:company', function (req, res) {
var company = req.company;
company = _.extend(company, req.body);
company.save(function(err) {
if (err) {
return res.send('/company', {
errors: err.errors,
company: company
});
} else {
res.jsonp(company);
}
})
});
This mean stack project may help you as it covers this CRUD functionality which I just used here swapping their articles for your companies. same same.

Your callback function has the arguments in the wrong order.
Change the order of callback to function(req, res).
Don't use function(res, req).

Also if you want to redirect in put or delete (to get adress), you can't use normal res.redirect('/path'), you should use res.redirect(303, '/path') instead. (source)
If not, you'll get Cannot PUT error.

Have you been checking out your headers information?
Because header should be header['content-type'] = 'application/json'; then only you will get the update object in server side (node-express), otherwise if you have content type plain 'text/htm' like that you will get empty req.body in your node app.