Updating translatable fields to null or empty is not working as expected

[kskrlinnorth2]

Example for create:

Model::create([
    'name' => ['en' => 'Name en', 'hr' => 'Name hr'],
    'description' => ['en' => 'Desc en', 'hr' => 'Desc hr'],
]);

In DB I get data saved as JSON (as expected).

Example for update:

$model->update([
    'name' => ['en' => 'Name en', 'hr' => 'Name hr'],
    'description' => null,
]);

In DB I am getting {"en":null} instead of null. Why isn't saved as null (it is nullable column in DB), but as en: null?

[anibalealvarezs]

Unless you include a key/value pair specifying which language the null value refers to, it will assign it to the current app language.
Since your current language is en, it will be stored as {"en": null}

Remember that the mutation will work for each field independently. So, it will work the same as

$model->update([
    'name' => ['en' => 'Name en', 'hr' => 'Name hr'],
]);
$model->update([
    'description' => null,
]);

The update() method you're using is related to the Model, so the mutation will work for all the fields you have specified in the model definition. I assume you're using the find() method from the Builder to get the model instance: https://laravel.com/api/9.x/Illuminate/Database/Eloquent/Builder.html#method_find

A different case would have been using the Collection update() method, which would have ignored the mutation and you would have been able to assign a custom value to the field.

For example:

$collection = Model::get() // <= This is a "collection", not a "model instance"
$collection->update([
    'description' => null,
])

That's because the get() method returns a collection instead of a model instance: https://laravel.com/api/9.x/Illuminate/Database/Eloquent/Builder.html#method_get

[kratos-digital]

I also stumbled on this problem today after client reported that current translations aren't getting removed when values for each locale is empty on update.
I fixed it by overriding the default HasTranslation trait which works for my case.

<?php

namespace App\Http\Traits;

use Spatie\Translatable\HasTranslations as BaseHasTranslations;

trait HasTranslations
{
    use BaseHasTranslations;
    
    public function setAttribute($key, $value)
    {
        // Force prop to be set as null
        if ($value === null) {
            $this->attributes[$key] = null;
            return;
        }

        if ($this->isTranslatableAttribute($key) && is_array($value)) {
            return $this->setTranslations($key, $value);
        }

        // Pass arrays and untranslatable attributes to the parent method.
        if (! $this->isTranslatableAttribute($key) || is_array($value)) {
            return parent::setAttribute($key, $value);
        }

        // If the attribute is translatable and not already translated, set a
        // translation for the current app locale.
        return $this->setTranslation($key, $this->getLocale(), $value);
    }
}