The problem is related to promises. I just started learning Express, and using to make HTTP requests.
The app relies heavily on making external requests to function, so for this reason, I am ending up with a very ugly app that is primarily a nested mess.
Example of a scenario (dummy code):
app.get('/v1/example', async function(req, res) {
let bearer = null;
try {bearer = req.header('authorization').split(' ')[1];}
catch (e) {bearer = params.token;}
checkUser(bearer).then(r => {
res.json(r.data);
res.json(r.data);
action1(bearer).then(r => {
action2(bearer).then(r => {
res.json(r.data);
}).catch(e => {
try {
res.status(e.response.status);
res.send(e.response.data);
}
catch (e) {console.log('oops')}
})
}).catch(e => {
try {
res.status(e.response.status);
res.send(e.response.data);
}
catch (e) {console.log('oops')}
})
}).catch(e => {
try {
res.status(e.response.status);
res.send(e.response.data);
}
catch (e) {console.log('oops')}
})
})
Is there a better way to do that? Knowing that in a more elegant fashion? How can I properly wait for the above previous promise to complete before firing up the function below?
Is there anything that you can suggest?
Right now, I did a very dirty trick, and of course, this doesn't scale: I am setting up an interval that checks if the variable that I need is defined or not, and when the variable is finally defined, it exits the interval and timeout.
const intervalObj = setInterval(function() {
let MIME = helpers.getMIME(image_response.extension)
const file = image_response.image_path;
const fileExists = fs.existsSync(file);
if (fileExists) {
clearInterval(intervalObj);
// do the next task.
}
}, timeout);
Thank you.
