New feature suggested for Dropdown: able to disable Popper's preventOverflow

[mapher87]

Get an issue when using Menu forms with a large form which is supposed to fix itself below the button.
The PreventOverflow feature is good, but we'd disable it in a lot of cases which is impossible when using Dropdown.

Thanks and Best Wishes.

[Johann-S]

Bug reports must include a live demo of the problem. Per our contributing guidelines, please create a reduced test case via CodePen or JS Bin and report back with your link, Bootstrap version, and specific browser and OS details.

[mapher87]

https://codepen.io/anon/pen/QQjKEJ
Click the button several times or scroll up and down, you will see the form reset its position by the preventOverflow feature.

This case use bootstrap 4.0.0 beta3

[Johann-S]

A quick fix would be to add this line on your application :

Popper.Defaults.modifiers.preventOverflow = { enabled: false };

See the result here (with our first stable v4) : https://codepen.io/Johann-S/pen/vdNymv?editors=1010

Side note : not possible to do that if you use bootstrap.bundle.js or bootstrap.bundle.min.js

[mapher87]

As there is an option "data-boundary" to manage the behavior of the preventOverflow, would you like to disable one Dropdown's preventOverflow feature by given false or null?

For example:

<button type="button" data-boundary="false" ...>
  button
</button>

[Johann-S]

They are a PR to disable Popper.js for dropdown : #24092

[mdo]

Closing as stale for v4. We'll be moving onto focus entirely on v5 and v4 will only see critical updates.