Develop Reference

Getting Console Messages on Webpage NodeJS

I'm wondering if there's any way to listen for console messages and act on console messages when they're received. Mainly, is there any way to do this without an external module, and using the http module?
The goal is to trigger a NodeJS function or code snippet on an event like click in the HTML. If there's also a way to do this, then that's great. But once again, I'd like to do this without an external module, and just use those that are built-in to NodeJS.

Use onclick() function in JavaScript to trigger a function call when clicking on a element. Then use fetch to make a api call to the nodejs server.

I know #Haris Wilson already got the answer, but I'd just like to provide a code example.
Instead of trying to catch a console message and then execute a function if we find it, we can use fetch() to make a request to whatever URL we need, and this can allow us to make other requests.
In this case, we can use the url module and the http module to parse the url and serve the API and website, respectively.
const url = require('url')
const http = require('http')
const requestListener = async function (req, res) {
// Basic server setup
res.writeHead(200, {
'Content-Type': 'text/html'
});
res.end(/** Content here */)
// API
if (url.parse(req.url, true).pathname === '/APIcall') {
let arguments = url.parse(req.url, true).query
// Preform necassary actions here
}
}
We can now use onClick to call a function inside our webpage JavaScript, and use fetch([API URL]) to give our NodeJS data to preform an action. We can use URL params to do this, such as https://localhost:8080/APIcall?data=someData&moreParam=more-data, where ?data=someData&moreParam=more-data are the URL params.

Express server route format

I have two different types of possible API class I can make.
The first one is:
http://api_url.com/api/v1/schools/countries/BR
and the second one is:
http://api_url.com/api/v1/schools/countries/BR?admin1=MA
My route in backend/routes/schools.js is:
router.get('/countries/:country', forward_get);
const forward_get = (req, res, next) => {
console.log(req);
const url = `${url}${req.originalUrl}`
getResponse(url, acToken, res);
}
How do I make it so that I am able to also make the second api call and get the appropriate parameters "admin1: MA". Ive gone through the whole req object and I don't seem to find them anywhere. So far I've been able to make the first api call without a problem.

This is the only route you need:
You access admin1 using req.query.admin1
and
You access country using req.params.country

Neither Node.js PUT or POST routes are presenting the data that is being received

I tried this with a number of different modules and methods.
Even by proving the other modules do work as expected in Node by building a separate test project and testing each module individually.
Posting FROM Node's hosted router to a remote API (not TO Node's hosted API)
This problem is not one of SENDING data to an API. It must IMO a problem in the receiving API's not giving up the data it IS receiving for some reason.
I've proven the PUT or POST calls are sending the data by sending the call to http://httpbin/org. That site shows me I'm sending what I expect to be sending.
Here is how I'm sending. I can even see in the receiving API that that API is certainly getting called successfully.
-- sending -- ((Again. This shows my node.http attempt. But I get the same problem using requestjs, requestifyjs, needlejs))
router.get('/', function (req, res, next) {
var hst = req.headers.host.split(':');
var lookbackURL = 'https://' + req.headers.host + req.baseUrl;
lookbackURL = 'http"httpbin.org/put';
var dat = {
what: 'ever'
, try: 'again'
};
var bdy = JSON.stringify(dat);
var options = {
host: hst[0], port: hst[1], path: req.baseUrl, method: 'PUT'
, headers: { 'Content-Type': 'application/json' }
};
var r = nodeHttp.request(options); r.write(bdy); r.end();
res.sendStatus(200);
});
-- receiving --
router.put('/', function (req, res, next) {
console.log('r', req);
});
No matter what module or method I use, in all cases, the receiving req object doesn't contain the what or try data.
BUT in my test project the data is there as I expect it to be, in all cases.
Doing the same console.log(req); in the test project, reqestjs, requestjs, needlejs, node.http all show a proper body object.
But in this problem there isn't a body object in req.
And sending this put/post to http://httpbin.org I can see the body object is being sent.
Any ideas?

Issue found. And it was something no one on here could have gotten for the code I posted.
For reasons I will not go into I have to take body-parser out this application. This also means app.use() won't have a parser given to it.
And that means I have to deal with getting the data on my own. So I've added a req.on('data') listener to read the chunk from the call to the API.
router.put('/', function (req, res, next) {
var data = '';
req.on('data', function (chunk) {
data += chunk;
.....
});
.....
I also decided to do this as a PUT using Requestify.
This just goes to show how easy it is to become complacent and forget how things really work; the assumption of body-parser (or other things) always being there for instance. Or what it is really doing for you.
NEXT I have to figure out how to get a value out of the `req.on('data) back to the method PUTting to the API. Any tips? Appreciated.

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.