Happydevdays Happydevdays - 2 months ago 6
Node.js Question

node / express REST API application - passing parameters to GET method

Background

I'm writing a sample nodejs / express REST interface or API for the purposes of learning. I've created a new route called "emergency".

In the file I have the following code:

router.get('/', function(req, res, next) {
//var ip = req.params.ip;
res.send('respond with a resource');
});


When I start the application and navigate to http://myserver/tutorial1/emergency
everything works fine and I see the "respond with a resource" message.

Goal

I'd like my application to be able to accept parameters as well. So fro example, when a user navigates to

http://myserver/tutorial1/emergency


I want all emergency numbers to be queried and returned. But they should also be able to do this:

http://myserver/tutorial1/emergency/12345


and the system should query the database for emergency record 12345 and return the appropriate result set.

Problem / Question

In order to accommodate both types of GET queries, I've changed the code to look like this:

router.get('/id', function(req, res, next) {
//var ip = req.params.ip;
res.send('respond with a resource');
});


Now when I run the application, and browse to

http://myserver/tutorial1/emergency/12345


it works. However, browsing to

http://myserver/tutorial1/emergency


fails with a 404 error message.

Not Found

404

Error: Not Found
at /var/www/html/nodejs_samples/tutorial1/app.js:34:13
at Layer.handle [as handle_request] (/var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/layer.js:95:5)
at trim_prefix (/var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:312:13)
at /var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:280:7
at Function.process_params (/var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:330:12)
at next (/var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:271:10)
at /var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:618:15
at next (/var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:256:14)
at Function.handle (/var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:176:3)
at router (/var/www/html/nodejs_samples/tutorial1/node_modules/express/lib/router/index.js:46:12)


Do I need to create two separate methods, one that accepts a parameter and one that doesn't? (aka method overloads?)
Perhaps my understanding of REST is what's faulty. Should a GET request look like :

http://myserver/tutorial1/emergency


or should it always look like this:

http://myserver/tutorial1/emergency/{id}


Maybe the proper way to do a GET for all records is something like this:

http://myserver/tutorial1/emergency/all


I'm trying to google my question right now as well, but I'm having a hard time expressing it succinctly enough to get an accurate search result set.

EDIT 1

This is what my code looks like when I try to create two methods (and this works)

router.get('/', function(req, res, next) {
res.send('respond with a resource');
});

router.get('/:id', function(req, res, next) {
var id = req.params.id;
console.log(id);
res.send('got it');
});


But this just feels odd because I guess I'm used to other frameworks in other languages where the system can check for empty params so you just need one method.
this is not a complaint! just a comment that might explain why my brain is "expecting" the system to work a different way.

Tom Tom
Answer

Do I need to create two separate methods, one that accepts a parameter and one that doesn't?

I'm guessing you posted this before even trying that?

The answer is yes.

Your route that accepts parameters should look like this:

app.get('/emergency/:id', function (req, res, next) {
    var id = req.params.id;
    console.log('The id: ' + id);
});
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