BelongsTo field resets after changing value when depends on other field

[kusab85]

• Laravel Version:10.22.0
• Nova Version: 4.27.12
• PHP Version: 8.2.4
• Database Driver & Version: SQL lite
• Operating System and Version: Windows 10 22H2
• Browser type and version: FF, Chrome
• Reproduction Repository: https://github.com/kusab85/TestApp/tree/BelongsTo-resets-when-dependsOn-other-field

Description:

Value of BelongsTo field resets to its initial value when dependsOn other field.

/**
 * App/Nova/Post.php 
 */

    public function fields(NovaRequest $request)
    {
        return [
            // [...]
            BelongsTo::make('User')
                ->dependsOn(
                    ['created_at'],
                    function (BelongsTo $field, NovaRequest $request, FormData $formData) {
                        $field->help(
                            '$formData = '.var_export($formData->getAttributes(), true)."</br>\n".
                            '$field->value = '.var_export($field->value, true)
                        );
                    }
                ),
           // [...]
        ];
    }

1. Initial state of form (creating new post)

2. Selecting a user

3. Setting creation date

4. Form state after creation date setting

Detailed steps to reproduce the issue on a fresh Nova installation:

Check reproduction repository.

[crynobone]

You shouldn't use $field->value as we need to determine whether it is undefined or null from dependsOn. You should be able to get the current value from $formData.

[kusab85]

So, if I stop reading $field->value on server side the form field will stop resetting on client side? That's quite inobvious behavior ;-)

[crynobone]

https://github.com/laravel/nova-dusk-suite/blob/10.4/tests/Browser/DependentBelongsToFieldTest.php#L112-L155

This this in Nova repository hasn't failed yet, which should have if what you claimed did happened.

[kusab85]

So @crynobone, please tell me if I'm misreading the test_it_reset_the_field_value test entirely.

The expected behavior of dependent BelongsTo field is to reset to its original value (null on creating) as soon as field on which it depends on changes its value?