iOS 12.2 scroll hangs

[BumbleeLin]

Our app seems to have the scrolling hang on certain pages. In the CDVWKWebViewEngine.m file on the (void)handleStopScroll method when I change the last line from -

a) [wkWebView evaluateJavaScript:@"window.IonicStopScroll.fire()" completionHandler:nil];

To -

b) [wkWebView evaluateJavaScript:@"window.IonicStopScroll.cancel()" completionHandler:nil];

The scrolling then seems to work. I'm not sure if there is an issue with this section in the wk-plugin.js file -

 var stopScrollFunc = null;
  var stopScroll = {
    stop: function stop(callback) {
      if (!stopScrollFunc) {
        stopScrollFunc = callback;
        stopScrollHandler.postMessage('');
      }
    },
    fire: function fire() {
      stopScrollFunc && stopScrollFunc();
      stopScrollFunc = null;
    },
    cancel: function cancel() {
      stopScrollFunc = null;
    }
  };

  window.Ionic.StopScroll = stopScroll;
  // deprecated
  window.IonicStopScroll = stopScroll;

[bryplano]

@BumbleeLin - do you happen to have reproduction steps & a sample application that exhibits the issue?

I'm working with someone on a similar issue, but haven't yet experienced this issue myself. If you have the chance to write up a simple demo app and post that here, that'd be great!

Edit: Additionally, if you can post more information about your app environment (post the outputs of ionic info and cordova plugin ls), that'd be great.

[bryplano]

@Baadier-Sydow you're also welcome to post a sample application if this is an issue for you :) we're trying to look into it but have no viable reproduction steps / sample app at the moment.

[BumbleeLin]

@bryplano awesome. I will try to help with a sample app. See below the Ionic info:

cli packages: (/usr/local/lib/node_modules)

@ionic/cli-utils  : 1.19.2
ionic (Ionic CLI) : 3.20.0

global packages:

cordova (Cordova CLI) : 8.0.0

local packages:

@ionic/app-scripts : 3.1.6
Cordova Platforms  : android 6.2.2 ios 4.5.5
Ionic Framework    : ionic-angular 3.6.0

System:

ios-deploy : 1.9.4
Node       : v8.11.4
npm        : 6.4.1
OS         : macOS
Xcode      : Xcode 9.4.1 Build version 9F2000

Environment Variables:

ANDROID_HOME : not set

Misc:

backend : pro

---------------------------->

Below is the plugin list :

com-sarriaroman-photoviewer 1.1.10 "PhotoViewer"
cordova-plugin-actionsheet 2.3.1 "ActionSheet"
cordova-plugin-camera 2.4.1 "Camera"
cordova-plugin-compat 1.1.0 "Compat"
cordova-plugin-console 1.1.0 "Console"
cordova-plugin-device 1.1.3 "Device"
cordova-plugin-fcm 2.1.2 "FCMPlugin"
cordova-plugin-geolocation 2.4.1 "Geolocation"
cordova-plugin-inappbrowser 2.0.2 "InAppBrowser"
cordova-plugin-ionic-webview 4.0.0 "cordova-plugin-ionic-webview"
cordova-plugin-network-information 1.3.3 "Network Information"
cordova-plugin-splashscreen 4.0.0 "Splashscreen"
cordova-plugin-statusbar 2.2.0 "StatusBar"
cordova-plugin-velda-devicefeedback 0.0.2 "DeviceFeedback"
cordova-plugin-whitelist 1.3.0 "Whitelist"
cordova-sqlite-storage 2.0.4 "Cordova sqlite storage plugin"
cordova.plugins.diagnostic 3.6.5 "Diagnostic"
ionic-plugin-keyboard 2.2.1 "Keyboard"
uk.co.workingedge.phonegap.plugin.launchnavigator 3.2.1 "Launch Navigator"

I will continue to dig deeper into this issue and let you know if I have any updates.

[bryplano]

@BumbleeLin awesome! Thank you so much :) we're working on it from our end as well, so we'll be sure to update if we find anything.

[kensodemann]

Here is a sample app that shows the behavior: https://github.com/kensodemann/test-scroll

Run on a phone that is running iOS 12.2 Beta 4

On home, press the button, which opens a child that will not scroll.
Make the change that @BumbleeLin specifies in the original post and rebuild
Now the scroll works when the child page is navigated to

[Baadier-Sydow]

@bryplano I'm on the same team as @BumbleeLin

Unfortunately the project is too large for us to create something reproducible as we arent sure on the root cause. It seems like @kensodemann may have something that can help.

[Baadier-Sydow]

@kensodemann @bryplano What @BumbleeLin didnt mention is that even after that change we have one or two screens that still dont work. We are going to see if we can find the root cause but arent really making any headway.

[bryplano]

@Baadier-Sydow no problem! Thanks for clarifying and thanks to @kensodemann for the demo app.

We're taking a look at this on our end and will post once we have any update.

[bryplano]

I wrote up a separate issue for the Ionic v3 repo: ionic-team/ionic-v3#984

Probably best to follow both issues as last I checked, the team is working on determining where a fix would come from. Suspicion is a Webkit / Safari issue but still working it out :)

[Baadier-Sydow]

I'm going to add another issue that was up by one our testers both here and on the v3 repo as it could be linked. We have a feature that opens an external site in an inappbrowser and then returns back to the application.

We started with the Ionic side menu starter and according to the testers the menu intermittently stops responding to the press to open it ie the menu does not slide open when we get focus back from the inappbrowser.

This was working prior to iOS 12.2.

[jcesarmobile]

I think it has been fixed on 12.2 beta 6

[bryplano]

@BumbleeLin - I have closed my issue on the v3 repo because the problem no longer exists after installing iOS 12.2 Beta 6 (released earlier this week).

Reference: ionic-team/ionic-v3#984

Could you check and see if you still have issues?

[Baadier-Sydow]

Thanks @bryplano @BumbleeLin and I will have a look 👍

[BumbleeLin]

@bryplano cool bro, will give you feedback on this

[BumbleeLin]

@bryplano yo man, I'm still not having any luck with the scroll issue. Do you perhaps have any other suggestions? I have updated the device to iOS 12.2 beta 6 and used XCode 10.2 beta 4.