Expo: Standalone app doesn't start in offline

[serhiipalash]

Environment

| software | version
| ---------------- | -------
| expo | 27.0.0
| react-native | https://github.com/expo/react-native/archive/sdk-27.0.0.tar.gz
| device | iPhone 6s, iPhone 8

exp diagnostics output

App's target is iOS Standalone

Steps to Reproduce

1. Create new Expo-project

2. Add this in App.js

import React from 'react'
import { View } from 'react-native'

export default class App extends React.Component {
  render() {
    return <View style={{ flex: 1, backgroundColor: 'mediumspringgreen' }} />
  }
}

1. Add this in app.json

{
  "expo": {
    "name": "test",
    "description": "",
    "slug": "test",
    "scheme": "testapp",
    "privacy": "unlisted",
    "sdkVersion": "27.0.0",
    "version": "1.0.0",
    "orientation": "portrait",
    "platforms": ["ios"],
    "primaryColor": "#cccccc",
    "icon": "./assets/icons/app-icon.png",
    "splash": {
      "image": "./assets/img/splash.png",
      "resizeMode": "contain",
      "backgroundColor": "#ffffff"
    },
    "updates": {
      "fallbackToCacheTimeout": 0
    },
    "assetBundlePatterns": ["**/*"],
    "ios": {
      "buildNumber": "1",
      "supportsTablet": true,
      "bundleIdentifier": "<your_indentifier>",
      "config": {
        "usesNonExemptEncryption": false
      }
    },
    "android": {
      "package": "<your_indentifier>"
    }
  }
}

1. Run exp build:ios

2. Upload build to iTunes Connect

3. Install app on your phone with TestFlight

4. Turn off wifi

5. Open the app

You will see splash screen and app will stall like this.

Expected Behavior

App should start in offline without any problems.

Actual Behavior

When you start app in offline you see splash screen and that's all.

Reproducible Demo

No demo.
In Simulator all works fine when I disable network on my Mac. I tried with and without "Development mode" in Simulator and everything works fine. The problem is only with standalone app.

@brentvatne, @aalices please fix it.

We have spent much time to implement network independent start for our users. Our app should start and look the same independent from network connection. It was working in Expo 26.

Thanks!

[schazers]

Hi, thanks for the detailed report. I'm flagging @terribleben who should know more.

[serhiipalash]

Thanks @schazers!

[sebastian-schlecht]

Experiencing the same issue with pretty much the same config as described above. Using a HTTP proxy, one can see that the app makes a call to _exp.host_ when starting. Disabling the proxy makes the app stop working. However, redirecting or terminating that request (such that 400 is returned for example) makes the app work again.

[serhiipalash]

@sebastian-schlecht if you can reproduce it on your machine can you try to set fallbackToCacheTimeout to 1000 or any non-zero value.
I wanted to try this but it is really annoying to spend 40 minutes on building the app each time I want to test something.

[sebastian-schlecht]

What I already tried was to not use the update property at all. I did not set fallbackToCacheTimeout to a non-zero value though. As to the former - no success. Still didn't work.

[serhiipalash]

Thanks!

{
  "updates": {
    /* 
      If set to false, your standalone app will never download any code.
      And will only use code bundled locally on the device. 
      In that case, all updates to your app must be submitted through Apple review. 
      Defaults to true.

      Note that this will not work out of the box with ExpoKit projects.
    */
    "enabled": BOOLEAN,

    /* 
      By default, Expo will check for updates every time the app is loaded.
      Set this to `'ON_ERROR_RECOVERY'` to disable automatic checking unless recovering from an error.

      Must be one of `ON_LOAD` or `ON_ERROR_RECOVERY`. 
    */
    "checkAutomatically": STRING,

    /* 
      How long (in ms) to allow for fetching OTA updates before falling back to a cached version of the app. 

      Defaults to 30000 (30 sec). Must be between 0 and 300000 (5 minutes). 
    */
    "fallbackToCacheTimeout": NUMBER
  }
}

Can you try to set

"updates": {
    "enabled": false,
}

or

"updates": {
    "checkAutomatically": "ON_ERROR_RECOVERY",
}

?

[sebastian-schlecht]

I actually didn‘t resort to that because I really wanted to keep OTA updates enabled. It provides a lot of flexibility to us in terms of deployment.

On 7. Jun 2018, at 23:22, Serhii Palash [e-mail] wrote:

Thanks!

{
"updates": {
/*
If set to false, your standalone app will never download any code.
And will only use code bundled locally on the device.
In that case, all updates to your app must be submitted through Apple review.
Defaults to true.

  Note that this will not work out of the box with ExpoKit projects.
*/
"enabled": BOOLEAN,

/* 
  By default, Expo will check for updates every time the app is loaded.
  Set this to `'ON_ERROR_RECOVERY'` to disable automatic checking unless recovering from an error.

  Must be one of `ON_LOAD` or `ON_ERROR_RECOVERY`. 
*/
"checkAutomatically": STRING,

/* 
  How long (in ms) to allow for fetching OTA updates before falling back to a cached version of the app. 

  Defaults to 30000 (30 sec). Must be between 0 and 300000 (5 minutes). 
*/
"fallbackToCacheTimeout": NUMBER

}
}
Can you try to set?

"updates": {
"enabled": false,
}
or

"updates": {
"checkAutomatically": "ON_ERROR_RECOVERY",
}
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[serhiipalash]

I really wanted to keep OTA updates enabled

I want the same.

I just want to know where is the bug. This will speed up its fix.

[msevestre]

To summarize, it is not possible to load an expo app on iOS while offline. It happens not only the first time the app is started but every time? Is this correct?

[serhiipalash]

@msevestre

it is not possible to load an expo app on iOS while offline.

Yes, it is. If you use Expo AppLoading component your app will not start in offline on iOS.

For example, we detect device locale before we show the app to the user. Until device locale is detected we need to show some loader screen and we use Expo AppLoading component for it.

The problem is that Expo AppLoading component doesn't work in offline. We pass in it promise that detects locale or any other promise, but the result is always the same - promise was resolved but AppLoading is still there, onFinish never fires in offline.

[serhiipalash]

It happens not only the first time the app is started but every time? Is this correct?

Yes, it is correct.

[msevestre]

I can reproduce the problem in an app that is not using the AppLoading component.
Basically using the default app that I pushed on testflight. As soon as I go on airplane mode, I can't start the app...

[serhiipalash]

As soon as I go on airplane mode, I can't start the app...

How does it look? You should see at least something - your app logo or splash screen.

[msevestre]

Yeah that's right. Slash screen that loads forever. Very same symptoms as
what you described but without the AppLoading component.

Unless the AppLoading component is used implicitly.

On Sun, Jun 10, 2018, 11:46 AM Serhii Palash [e-mail]
wrote:

As soon as I go on airplane mode, I can't start the app...

How does it look? You should see at least something - your app logo or
splash screen.

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[serhiipalash]

Ok, thanks @msevestre !
I'll try to build today simple app with one View component and test if it starts in offline.
I'll change this issue description if it is not related to AppLoading component.

[serhiipalash]

@msevestre I have tested standalone app with one View component in offline and got the same results like you did. So the problem is not in AppLoading component but with Expo itself.

This is what was in my App.js

import React from 'react'
import { View } from 'react-native'

export default class App extends React.Component {
  render() {
    return <View style={{ flex: 1, backgroundColor: 'mediumspringgreen' }} />
  }
}

and the standalone app just doesn't start while offline, I see splash screen forever.

@brentvatne, @schazers please fix it in next release.
I think this is critical bug for everyone who builds an app with Expo.

[brentvatne]

@serhiipalash - ios / android? what's in your app.json there?

[brentvatne]

cc @esamelson

[brentvatne]

verified this using a simulator build of a new project with blank template: https://exp-shell-app-assets.s3-us-west-1.amazonaws.com/ios%2F%40notbrent%2Ftest-offline-b820a2ac-1492-486a-83b1-5753ae45a839-simulator.tar.gz

[serhiipalash]

what's in your app.json there?

in app.json that what I wrote in first message in this chat

{
  "expo": {
    "name": "test",
    "description": "",
    "slug": "test",
    "scheme": "testapp",
    "privacy": "unlisted",
    "sdkVersion": "27.0.0",
    "version": "1.0.2",
    "orientation": "portrait",
    "platforms": ["ios"],
    "primaryColor": "#cccccc",
    "icon": "./assets/icons/app-icon.png",
    "splash": {
      "image": "./assets/img/splash.png",
      "resizeMode": "contain",
      "backgroundColor": "#ffffff"
    },
    "updates": {
      "fallbackToCacheTimeout": 0
    },
    "assetBundlePatterns": ["**/*"],
    "ios": {
      "buildNumber": "2",
      "supportsTablet": true,
      "bundleIdentifier": "<our_indentifier>",
      "config": {
        "usesNonExemptEncryption": false
      }
    },
    "android": {
      "package": "<our_indentifier>"
    }
  }
}

ios / android?

ios

We don't have Android app and I can't test it.

[msevestre]

Works on Android. Issue is only with iOS. No offline capability at all

On Sun, Jun 10, 2018, 2:11 PM Serhii Palash [e-mail]
wrote:

what's in your app.json there?

in app.json that what I wrote in first message in this chat

{
"expo": {
"name": "test",
"description": "",
"slug": "test",
"scheme": "testapp",
"privacy": "unlisted",
"sdkVersion": "27.0.0",
"version": "1.0.2",
"orientation": "portrait",
"platforms": ["ios"],
"primaryColor": "#cccccc",
"icon": "./assets/icons/app-icon.png",
"splash": {
"image": "./assets/img/splash.png",
"resizeMode": "contain",
"backgroundColor": "#ffffff"
},
"updates": {
"fallbackToCacheTimeout": 0
},
"assetBundlePatterns": ["*/"],
"ios": {
"buildNumber": "2",
"supportsTablet": true,
"bundleIdentifier": "",
"config": {
"usesNonExemptEncryption": false
}
},
"android": {
"package": ""
}
}
}

ios / android?

ios

We don't have Android app and I can't test it.

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[sebastian-schlecht]

It also works on Android on our end. Issue only occurs for iOS standalone builds.

[msevestre]

From #1847

Keeping ON_LOAD and setting fallbackToCacheTimeout to 1 will also allow the app to load with no network, so it seems that the 0 value is not working as intended, which should not wait for any updates per the documentation.

Maybe this could be seen as a workaround in the meantime (#1847 is a detached app but its description sounds very much like what we are discussing here)

[serhiipalash]

@msevestre setting falbackToCacheTimeout to 1 didn't help

[sebastian-schlecht]

@serhiipalash did you also set "checkAutomatically": "ON_LOAD" (or is that the default anyway)?

[serhiipalash]

@msevestre I didn't set checkAutomatically, but I think its default value is ON_LOAD

[sebastian-schlecht]

@terribleben any thoughts on this?

[wanxger]

I had the same problem. I use Expo create a tool for iOS. It can't launch in offline.

[msevestre]

Is there any workaround at all? Would disable OTA update solve the issue in the meantime?

[esamelson]

Hi all -- I'm looking into this now. We should have a fix ready soon. Really sorry about this!!

[serhiipalash]

Thanks @esamelson !

[msevestre]

Awesome @esamelson. Thanks for being so reactive

[msevestre]

Hi all,

I just tried using the fix proposed in #1847

"checkAutomatically": "ON_LOAD"
"falbackToCacheTimeout":1

and my test app works offline on IOS!!

So at least a workaround until @esamelson fixes the issue!

[sebastian-schlecht]

@msevestre do you use ExpoKit? Does this also work on default Expo?

[serhiipalash]

@sebastian-schlecht we have default Expo app and I tried to set

"checkAutomatically": "ON_LOAD"
"falbackToCacheTimeout":1

I explicitly set "checkAutomatically" to "ON_LOAD". It didn't help.

[msevestre]

Did you also update the version ios app version? You need to create a brand new version on Testflight for the changes to be picked up.

I am using expo out of the box. My test project was created with expo UI. No other customization

[serhiipalash]

Did you also update the version ios app version?

No, I just updated the build number

[sebastian-schlecht]

@msevestre did it fix the problem for you consistently? I also tried reinstalling the app once (completely new build number, etc.). It worked for the first few restarts and at some point it just stopped.

[msevestre]

I think you need to do it because changes in app.json require a full new build. At least it worked for me. -)

[serhiipalash]

changes in app.json require a full new build

Of course I built (not published) new app each time I changed app.json

[msevestre]

it worked for the first few restarts and at some point it just stopped.

Very interesting. I tried again after one hour or so of not using the ipad and indeed, it DOES NOT work anymore.

All right then. I think we need @esamelson to work his magic :)

[esamelson]

Hi everyone -- we landed a fix internally earlier today, but it's looking like it isn't going to make it out by the end of the day. We'll deploy it tomorrow morning instead. Again, really sorry to anyone who's blocked on this 😧 if you're on ExpoKit, you can fix this yourself by applying https://github.com/expo/expo/commit/0c5b721f8f2ae0e40f2ccf84caee45d44fbcbcda manually inside of the pod. Otherwise, just hold tight!!

[msevestre]

@esamelson you are the man! Well done.
What do we need to do to apply the patch? Build a new version of the app? Or is there a new expo release coming out tomorrow?

Cheers

[esamelson]

@msevestre yeah SDK 28 will be going out tomorrow, and once it's out you'll just need to build a new version of your app. (no need to update as the fix will be applied to 27 as well -- it's just that we deploy them all at once.)

[serhiipalash]

Thanks @esamelson !

[sebastian-schlecht]

Did the fix make it into the new release?

[serhiipalash]

Did the fix make it into the new release?

I am building it right now. I'll let you know in one hour.

[serhiipalash]

Running exp build:ios --release-channel=sanbox on Expo 27 without any changes in code creates ipa file that crashes each time I try to open it either online or offline.

Bug: https://drive.google.com/open?id=1v3OIeKWIscSE6KTW1iMuqd3VdcM2v1KS

Device: iPhone 6s, iPhone 8

Yesterday it was working at least with connected network. I tried to build twice and results are the same.

no need to update as the fix will be applied to 27 as well

@esamelson this seems wrong

This is our last one build logs if it helps you https://expo.io/builds/50197213-2df0-4a2b-a715-e8e6a4cc9d5d

@brentvatne

[serhiipalash]

I just updated to Expo 28. and the same bug is in 28 version.

[terribleben]

Hey all, this week's release included the fix for this regression. If you're seeing a problem with your standalone app not starting offline, please rebuild the native binary and try again.

Going to close this thread because it's difficult to tell what's going on at this point. If you think you found a new issue, feel free to open a new thread. Thanks!

[serhiipalash]

@sebastian-schlecht , @msevestre have tried to build? Does offline start work?

[msevestre]

@serhiipalash just triggered one but build is stuck in queue...same as yesterday.

[msevestre]

@serhiipalash I can confirm that my demo app (very simple app) now works online and offline consistently with this fix.

[serhiipalash]

@msevestre I built today and offline start works in our app too. Thanks for your help with this bug!

[smartsoul]

Hello, everyone. I meet the issue with expo 28.0.0 version on android platform. I build the APK file from expo service and install it to my phone. Shut down network and laucn the App, the app launched and show white screen and keep it forever! When I open network, relaunch the APP, the APP will show something, but some images show slowly. So my question:

1. The white screen on first lanch offine.
2. Image loading slowly.

[serhiipalash]

@smartsoul you should create new blank Expo project from XDE, build Android apk and test it like you described. Then we will know is this the same issue or not. If the new Expo project starts in offline then the issue is in your code and you need to share it so that we can advise you something.

[smartsoul]

@serhiipalash Thanks. I update version 29 and copy app.json from XDE example. And it works now.

My app.json:

{
"expo": {
"sdkVersion": "29.0.0",
"orientation": "portrait",
"icon": "./src/assets/icon.png",
"splash": {
"image": "./src/assets/splash.png",
"resizeMode": "contain",
"backgroundColor": "#ffffff"
},
"updates": {
"fallbackToCacheTimeout": 0
},
"assetBundlePatterns": ["*/"],
"ios": {
"bundleIdentifier": "com",
"supportsTablet": false
},
"android": {
"package": "com."
}
},
"ios": {
"usesNonExemptEncryption": false
}
}

[mnoandh]

Hi guys ... is there any works on caching a webview in EXPO ?