[Bug] nullable date in repeatable field is not working

[mamprogr]

Bug

What I did

I have a belongsToMany relation with a pivot table. The pivot table has nullable revoked_at attribute.

I am using repeatable field to fill the pivot table as follows:

What I expected to happen

revoked_at to be set correctly.

What happened

It works fine when I enter a date but it causes the following error when I keep it empty:

SQLSTATE[22007]: Invalid datetime format: 1292 Incorrect date value: '' for column `revoked_at` at row 1 (SQL: insert into `supervisor_course` (`course_id`, `revoked_at`, `user_id`) values (1, , 4))

What I've already tried to fix it

I tried to disable the strict mode as mentioned here, the error disappeared but the inserted value is 30/11/1899

Backpack, Laravel, PHP, DB version

When I run php artisan backpack:version the output is:

PHP VERSION:

PHP 7.4.9 (cli) (built: Aug 4 2020 11:52:41) ( ZTS Visual C++ 2017 x64 )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies

LARAVEL VERSION:

v8.37.0@cf4082973abc796ec285190f0603380021f6d26f

BACKPACK VERSION:

4.1.41@44770347b918e42c052d0a138c24535b43e32472

[pxpm]

@mamprogr

Sorry for taking time to come back here.

So, you are trying to populate a BelongsToMany relation with a repeatable field, at the present moment, that is not supported unless you are using #3410 this PR.

For the moment BelongsToMany work only with selectable elements.

Otherwise you need to override your store() method in SomeEntityCrudController and do the manual saving of supervisors. https://backpackforlaravel.com/docs/4.1/crud-operation-update#callbacks-1

If you give a try to that PR and your current problem is solved by it, please let us know in the comments, it could help to speed up the merging process.

I am going to close this as I don't think there is much more we can do here, please use the current solution provided or the PR. If you think I am wrong, please re-open 👍

Wish you the best,
Pedro