Please, remove the very old MooTools dependencies.
I have noticed in all my Helix3 / Helix Ultimate installations, that they load MooTools core and more. Especially the Frontend submission (edit.php) is a real problem. I guess, it also happens with media Custom fields and the editor XTD buttons modals. Some buttons/modals were replaced by TinyMCE modals... but the "Image XTD button" still loads the ancient MooTools window?!
Coud you try to create a Bootstrap 3, 4, 5 compatible variant?
In frontend, might it need a plugin/hack to get rid of the old Bootstrap 2 and JS stuff?
Component.php is involved in modal contents. So it might be worth to think about a custom component.php, or even an alternative file with its own name?! Specifically for modals or suitable for your framework.
QUICK TEST with media.php override from Protostar:
In my personal quick test with the Protostar media.php file, there is a tooltip script issue, and I can't get the actual Bootstrap modal display. I just see the dark overlay. That's all. No modal content is loaded. No images list/upload.
FYI, I have also tested Joomlart's T3 and the latest T4 framework. They have solved many issues in the FRONTEND submission and the TinyMCE modals. Even the XTD-button IMAGE modal looks nice, it is a TinyMCE modal!. But they also missed the Joomla core "Images & Links". The media fields do still load the old media.php and MooTools modal :( It's inner content styles are pretty good... but the modal height is totally wrong. Too small. Not usable. Maybe the other parts of T4 can be of any help and inspiration. Or the TinyMCE modal is an alternative workaround?
Please, remove the very old MooTools dependencies. I have noticed in all my Helix3 / Helix Ultimate installations, that they load MooTools core and more. Especially the Frontend submission (edit.php) is a real problem. I guess, it also happens with media Custom fields and the editor XTD buttons modals. Some buttons/modals were replaced by TinyMCE modals... but the "Image XTD button" still loads the ancient MooTools window?!
Joomla core media field in backend Isis and Protostar(!) template seem to use a different media.php, which results in a Bootstrap modal dialog. For quite some years now. Although I am confused about the Joomla core that it has the "old" one in place. See YourLatestJoomla -> layouts -> joomla -> form -> field -> media.php (MooTools version!) https://github.com/joomla/joomla-cms/blob/6639c074496bc575fb7458042360319519bd3536/layouts/joomla/form/field/media.php
Even Helix Ultimate v2 seem to rely on the old media.php, which loads media-mootools.js etc. https://github.com/JoomShaper/helix-ultimate/blob/95910d2b94bc0379c6a2eae0b1abf3c056bfab6d/plugins/system/helixultimate/html/layouts/form/field/media.php
Please, can you investigate the Joomla Protostar media.php solution? (I know, it still utilizes Bootstrap2!) https://github.com/joomla/joomla-cms/blob/6639c074496bc575fb7458042360319519bd3536/templates/protostar/html/layouts/joomla/form/field/media.php
BIG QUESTION & REQUEST:
Coud you try to create a Bootstrap 3, 4, 5 compatible variant? In frontend, might it need a plugin/hack to get rid of the old Bootstrap 2 and JS stuff? Component.php is involved in modal contents. So it might be worth to think about a custom component.php, or even an alternative file with its own name?! Specifically for modals or suitable for your framework.
QUICK TEST with media.php override from Protostar: In my personal quick test with the Protostar media.php file, there is a tooltip script issue, and I can't get the actual Bootstrap modal display. I just see the dark overlay. That's all. No modal content is loaded. No images list/upload.
FYI, I have also tested Joomlart's T3 and the latest T4 framework. They have solved many issues in the FRONTEND submission and the TinyMCE modals. Even the XTD-button IMAGE modal looks nice, it is a TinyMCE modal!. But they also missed the Joomla core "Images & Links". The media fields do still load the old media.php and MooTools modal :( It's inner content styles are pretty good... but the modal height is totally wrong. Too small. Not usable. Maybe the other parts of T4 can be of any help and inspiration. Or the TinyMCE modal is an alternative workaround?
Thanks in advance!