Module sending back api data - node.js

Question

I'm working on a module containing a class with functions which calls an api everytimes we use a function.
I want to handle the result & catch IN the module and only send data in return.
function getAllFromTable(aTableName){
const request = {
.... aTableName
}
return apiCall(request)
}
function apiCall(requestConfig){
axios(requestConfig).then(result => {
return result.data
}
.catch(err => {
return err
}
}
That's the idea of what I would like to do but of course this only sends back "undefined"..
Is there a way to make a return in a then() to send back the data ?
Or another way to send back only the data and not a Promise to the one who calls the function "getAllFromTable()" ?

Answer 1

Is there a way to make a return in a then() to send back the data ? Or another way to send back only the data and not a Promise to the one who calls the function "getAllFromTable()" ?
No. In Javascript, there is NO way to return an asynchronously retrieved result directly. You HAVE to use an asynchronous mechanism such as a promise, a callback or an event to communicate back the asynchronous result. Since you already have a promise, you need to just return the promise and make sure that its resolved value is your final result. Then, the caller can use either .then() or await to get the result out of the promise.
That's the idea of what I would like to do but of course this only sends back "undefined"..
In your apiCall() function, you have to return the promise and fix your error handling.
Change this:
function apiCall(requestConfig){
axios(requestConfig).then(result => {
return result.data
}.catch(err => {
return err
});
}
to this:
function apiCall(requestConfig){
return axios(requestConfig).then(result => {
return result.data;
});
}
I removed the .catch() because you were changing the promise from rejected to resolved and making the error object be the resolved value. That is unlikely what you want for the function behavior and very unlikely what the caller wants. If you want a .catch() to log the error or something, then you can throw the error again to make sure the promise stays rejected.
function apiCall(requestConfig){
return axios(requestConfig).then(result => {
return result.data;
}).catch(err => {
// log error and rethrow so the promise stays rejected
console.log(err);
throw err;
});
}
The caller of apiCall() will then either use .then() or await to get the resolved value of the promise that the function returns.
apiCall(...).then(val => {
console.log(val);
}).catch(err => {
console.log(err);
});