Ionic 5 - API request working on browser, not on emulated IOS - ios

Question

I have this Ionic 5/Capacitor app, which I'm making an API call to a local server from, that server running on docker at localhost:3000. When I test from the browser, the request is made fine. From Postman it requests fine, too. In my XCode logs the emulator, I see this
[error] - ERROR {"headers":{"normalizedNames":{},"lazyUpdate":null,"headers":{}},"status":0,"statusText":"Unknown Error","url":"http://localhost:3000/pins","ok":false,"name":"HttpErrorResponse","message":"Http failure response for http://localhost:3000/pins: 0 Unknown Error","error":{"isTrusted":true}}
The really interesting part, is that I'm running Fiddler to monitor the request as it's made. Fiddler gets a 200 as well, I can even see the response data. So, Fiddler sees the proper network call, but then my Ionic app gets that error. That makes me feel like it's an Ionic/Emulator/IOS problem, but I don't have enough familiarity with Ionic to know right off the bat what it is.
Here's the code responsible for making the request:
ngOnInit() {
const request = this.http.get('http://localhost:3000/pins');
this.refresh$.subscribe(
(lastPos: { latitude?: any; longitude?: number }) => {
request.subscribe(data => {
if (data) {
this.addMarkersToMap(data, lastPos);
}
});
}
);
}
And the HTTPClient imported in the constructor is from Angular:
import { HttpClient } from '#angular/common/http';

Answer 1

I ended up having to use this package, doing a check on if I'm on mobile or not.
https://ionicframework.com/docs/native/http/

Answer 2

Try with this :
const request = this.http.get('http://localhost:3000/pins', { observe: 'response', withCredentials: true });
Solution 2 : capacitor.config.json
"server": {
"hostname": "localhost", (maybe try precising the port number too)
}
Solution 3 : On your Express server (from https://ionicframework.com/docs/troubleshooting/cors)
const express = require('express');
const cors = require('cors');
const app = express();
const allowedOrigins = [
'capacitor://localhost',
'ionic://localhost',
'http://localhost',
'http://localhost:8080',
'http://localhost:8100'
];
// Reflect the origin if it's in the allowed list or not defined (cURL, Postman, etc.)
const corsOptions = {
origin: (origin, callback) => {
if (allowedOrigins.includes(origin) || !origin) {
callback(null, true);
} else {
callback(new Error('Origin not allowed by CORS'));
}
}
}
// Enable preflight requests for all routes
app.options('*', cors(corsOptions));
app.get('/', cors(corsOptions), (req, res, next) => {
res.json({ message: 'This route is CORS-enabled for an allowed origin.' });
})
app.listen(3000, () => {
console.log('CORS-enabled web server listening on port 3000');
});