Bootstrap 4 navbar mobile misbehaving when lifterLms is active

[Guillaume-Tnk]

Bug with mobile menu, not staying open when lifterlms is active with understrap theme

Reproduction Steps

• Install understrap theme https://understrap.com/
• Install and activate understrap child theme https://understrap.com/understrap-child-themes/
• Create some pages
• Create a menu and ad pages to it
• Install and activate lifterLms
• view website in mobile view with dev tools
• Click menu toggle

Expected Behavior

menu to open/close on click on mobile as it should

Actual Behavior

Menu rapidly close on mobile when clicked

View video below
https://youtu.be/O0DpAmoZz_c

[thomasplevy]

@Guillaume-Tnk any idea what piece of LifterLMS code is causing the issue?

[Guillaume-Tnk]

Unfortunately no, I just know it's coming from LifterLms because when I deactivate the lifterLms plugin, the problem disappears.
To be sure, I set a new WordPress install with just the theme and lifterLms nothing else as you can see from my video and the problem is there.

[eri-trabiccolo]

@thomasplevy collapse(.min).js
lifter uses collapse.js and transition.js from bootstrap3

which conflicts with the newer scripts of boostrap4.

p.s.
From a rapid search, though, couldn't find where lifter actually uses the collapse.js code.

[Guillaume-Tnk]

Any quick fix to get the menu to behave appropriately?

[thomasplevy]

@Guillaume-Tnk

You could try de-enqueing the offending conflicts in your child theme's functions.php file.

I don't have a timeline for fixing a theme conflict I've just been made aware of but I'd be very happy to have your help working on this.

Otherwise you'll have to wait until my and @eri-trabiccolo capacity becomes freed up to start slogging away on this issue backlog, which realistically won't be until Q1 2020. Sorry :-(

[cryptexvinci]

@Guillaume-Tnk

You can insert this snippet to dequeue the collapse js

add_action( 'wp_enqueue_scripts', 'remove_collapse_js', 100 );

if ( ! function_exists( 'remove_collapse_js' ) ) {
    function remove_collapse_js() {
       wp_dequeue_script( 'collapse' );
    }
}

[Guillaume-Tnk]

This is working! Thank you very much.

[eri-trabiccolo]

https://wordpress.org/support/topic/lifterlms-incompatible-with-arilewp-theme/

[eri-trabiccolo]

@thomasplevy maybe candidate for v4?

[thomasplevy]

Yea good idea, I'll have a look at this later today or tomorrow.