Calling an API endpoint from within another route in Node / Express - node.js

Question

I have myRoute.js with a route (GET) defined and I want to call an api endpoint from another route (api.js), and I'm not sure what the right way to do this is. The api.js route is working properly (image and code below).
api.js
router.get('/getGroups/:uid', function(req, res, next) {
let uid = req.params.uid;
db.getAllGroups(uid).then((data) => {
let response =[];
for (i in data) {
response.push(data[i].groupname);
}
res.status(200).send(response);
})
.catch(function (err) {
return err;
});
});
works as expected:
myRoute.js
I would like when a user goes to localhost:3000/USER_ID that the route definition gets information from the api. Psuedo code below (someFunction).
router.get('/:uid', function(req, res, next) {
let uid = req.params.uid;
let fromApi = someFunction(`localhost:3000/getAllGroups/${uid}`); // <--!!!
console.log(fromApi) ; //expecting array
res.render('./personal/index.jade', {fromApi JSON stringified});
});

Answer 1

Not sure if i understand you correct but anyway i will try to help. So you have an api like
router.get('/getGroups/:uid', function(req, res, next) {
let uid = req.params.uid;
db.getAllGroups(uid).then((data) => {
let response =[];
for (i in data) {
response.push(data[i].groupname);
}
res.status(200).send(response);
})
.catch(function (err) {
return err;
});
});
If you would like to reuse it you can extract a function from the code above like so:
async function getAllGroupsByUserId(uid){
const result = [];
try{
const data = await db.getAllGroups(uid);
for (i in data) {
result.push(data[i].groupname);
};
return result;
}
catch(e) {
return e;
}
}
And then reuse it in your api & anywhere you want:
router.get('/getGroups/:uid', async function(req, res, next) {
const uid = req.params.uid;
const groups = await getAllGroupsByUserId(uid);
res.status(200).send(groups);
})
Same you can do in your another route:
router.get('/:uid', async function(req, res, next) {
const uid = req.params.uid;
const fromApi = await getAllGroupsByUserId(uid); // <--!!!
console.log(fromApi) ; //expecting array
res.render('./personal/index.jade', {fromApi JSON stringified});
});
Seems like pretty clear :)

Answer 2

I would use fetch for this. You can replace someFunction with fetch, and then put the res.render code in a .then(). So, you would get this:
const fetch = require("node-fetch");
router.get('/:uid', function(req, res, next) {
let uid = req.params.uid;
fetch('localhost:3000/getAllGroups/${uid}').then(res => res.json()).then(function(data) {
returned = data.json();
console.log(returned); //expecting array
res.render('./personal/index.jade', {JSON.stringify(returned)});
});
});
A more robust way with error handling would be to write something like this:
const fetch = require("node-fetch");
function handleErrors(response) {
if(!response.ok) {
throw new Error("Request failed " + response.statusText);
}
return response;
}
router.get('/:uid', function(req, res, next) {
let uid = req.params.uid;
fetch('localhost:3000/getAllGroups/${uid}')
.then(handleErrors)
.then(res => res.json())
.then(function(data) {
console.log(data) ; //expecting array
res.render('./personal/index.jade', {JSON.stringify(data)});
})
.catch(function(err) {
// handle the error here
})
});
The ideal way would be to abstract your code into a method so you aren't calling yourself, as The Reason said. However, if you really want to call yourself, this will work.