Can't scroll on iOS

[2peter3]

I'm submitting a...

[X] Bug report
[ ] Feature request
[ ] Documentation issue or request

Current behavior

Can't scroll on iOS

Expected behavior

Scrolling :)

Minimal reproduction of the problem with instructions

Installing a fresh version with this Settings:

? What's the name of your app? bb
? What kind of app do you want to create? Web app, Mobile app (using Cordova)
? Do you want a progressive web app? (with manifest and service worker) Yes
? Which mobile platform do you want to support? iOS
? Which UI framework do you want? Bootstrap (more website-oriented)
? Do you want authentication? Yes

After this prepare cordova with:
npm run cordova:prepare

Now add some long text to src/app/home/home.component.html

example:

...
        </h1>
        <br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br
        />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />t<br />kkkkkkkkkk
        <app-loader [isLoading]="isLoading"></app-loader>
....

and build cordova with
npm run cordova:build

Go to XCode, Open Project and Select the Developer Team and Run it on Device.

Scrolling wont work, so nobody wont see "kkkkkkkkkk"

Environment

- generator version: v3.1.1
- node version: v9.3.0
- npm version: 5.6.0
- OS:  Mac

Others:

[sinedied]

I can reproduce the issue on the simulator. Did you also try it on a real device? (I don't have one at hand)

[2peter3]

Yes, i have tested it on real device iPhone 6s and Simulator :/

[2peter3]

you have any ideas/hints what could be the problem?

[sinedied]

Thanks for feedback for the real device test.
I'm currently trying to isolate the issue, I think it's something in Bootstrap that's causing the issue as the problem do not exist when using Ionic or Angular Material.
I am trying the latest Bootstrap beta branch to see if it fixes the issue, I'll keep you updated if I find something.

[sinedied]

Same behavior with latest Bootstrap beta, it seems that there's an element capturing the scrolling event, still investigating...

[sinedied]

Removing cordova-plugin-ionic-webview with ngx cordova plugin rm cordova-plugin-ionic-webview fixes the issues, but changes the webview to the slower UIWebView instead of WKWebView.

I will try with the official cordova WKWebView plugin to see if it works or not.

[2peter3]

i think i have found a solution... add to config.xml

<preference name="ScrollEnabled" value="true" />

between "" and

@sinedied could you approve it?

i tested this with simulator on Xcode 9.2 and iPhone 6s (latest updates) and it works

[sinedied]

I cannot test it at the moment, but it seems a viable fix, seeing https://github.com/ionic-team/cordova-plugin-ionic-webview/blob/master/src/ios/CDVWKWebViewEngine.m#L377

I could not find a documentation for this setting anywhere though, so I'm unsure of the reason for the default value being false. What's even more strange is that in previous cordova-plugin-ionic-webview version scrolling was working fine even without this settings 😕

Thanks for finding this fix, I'll add it specifically for the mobile/Bootstrap generation path since it's not needed when using Ionic or Angular Material 👍

[sinedied]

@2peter3 I just tested the workaround, the scrolling works as expected.
You may also want to change <preference name="UIWebViewBounce" value="false" /> with the true value to restore native webview bounce when scrolling.