React-Native fetch，网络请求失败。不使用localhost

Question

I have an app, which im using fetch to authenticate user. it was working till few days ago and i haven't change anything. just upgraded from react 0.27 to 0.28, not fetch is not working.

i have searched for almost 2 days and i have read almost all questions in stackoverflow. most of users trying to fetch something from localhost, and when they change it to actual ip address , they get it to work. but im not fetching anything from localhost, also mine code used to be working.

here is my code :

 fetch('http://somesite.com/app/connect', { method: 'POST', headers: { 'Accept': 'application/json', 'Content-Type': 'application/json', 'language':'en-US', 'Authorization': 'Bearer ' + access_token, }, body: JSON.stringify({ uid: uid, refresh_token: refresh_token, token: access_token, device: device_id, device_name: device_name, }) }) .then((response) => response.json()) .then((responseData) => { console.log(JSON.stringify(responseData.body)) }) .catch((err)=> { console.log('Some errors occured'); console.log(err); }) .done(); 

i tried to make some new projects, simple, just used a simple fetch example fro tutorials, it gave same error. i tried to open my website which im trying to connect to it, through browser in emulator, it works, but it seems through my, app cannot connect to any website/ip. it gives this error in chrome console :

TypeError: Network request failed
    at XMLHttpRequest.xhr.onerror (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:28193:8)
    at XMLHttpRequest.dispatchEvent (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:14591:15)
    at XMLHttpRequest.setReadyState (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:29573:6)
    at XMLHttpRequest.__didCompleteResponse (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:29431:6)
    at http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:29506:52
    at RCTDeviceEventEmitter.emit (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:13428:23)
    at MessageQueue.__callFunction (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:11999:23)
    at http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:11906:8
    at guard (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:11857:1)
    at MessageQueue.callFunctionReturnFlushedQueue (http://localhost:8081/index.ios.bundle?platform=ios&dev=true&hot=true:11905:1)

actually i have the same problem as this user here : React-native network request always fails

UPDATE : info.plist from xcode

any help will be appreciated!

Answer 1

You should check out this link: https://github.com/facebook/react-native/issues/8118

Looks like the issue emerged in React Native 0.28. Solution is to "Allow Arbitrary Loads" in the info.plist file found in the ios>build folder that React creates.

If you open the entire ios folder in xcode, then open this info.plist file you can create a new key to Allow Arbitrary Loads and it should fix your issue.

Answer 2

Set the info.plist doesn't work for me too. Trying to run on iOS.

Answer 3

This issue is the code is trying to fetch HTTP endpoint instead of HTTPS, which is not encouraged. If you are fetching from localhost server, an easy solution will be exposing your localhost server through a Ngrok https endpoint.

Steps:

1. Download ngrok and run ngrok http 8081 from terminal/cmd, where you should change 8081 to your localhost service port.

2. Ngrok will give you a https forwarding endpoint, simply use that to access your localhost server.