Support for Laravel strict mode by default defining $localeKey in translation models

[nekooee]

Describe the bug
When using Laravel's Model::shouldBeStrict() feature, an exception is thrown for any model using the laravel-translatable package if the $localeKey property is not manually defined in the translation model.

To Reproduce

1. Install astrotomic/laravel-translatable and configure it:

// config/translatable.php
'locale_key' => 'locale',

2. Enable Laravel strict mode in AppServiceProvider or elsewhere:

use Illuminate\Database\Eloquent\Model;

Model::shouldBeStrict(! app()->isProduction());

3. Use a model with translations (e.g., NavMenu model).
4. Attempt to access the model in a context that loads translations.

Expected behavior
The model should work normally under Laravel's strict mode without throwing a MissingAttributeException, assuming configuration is set correctly.

Screenshots

Versions (please complete the following information)

• PHP: 8.2
• Database: MySQL 8
• Laravel: 10.x (also tested on 11.x)
• Package: astrotomic/laravel-translatable v11.15

Additional context
The issue is resolved by manually adding this to each translation model:

protected $localeKey = 'locale';

It would be ideal if the package defined this property internally (e.g., via trait or base translation model), or documented this requirement for strict mode compatibility.

Exception

Illuminate\Database\Eloquent\MissingAttributeException  
The attribute [localeKey] either does not exist or was not retrieved for model [App\Models\NavMenu].

Stack Trace

#1 Illuminate\Database\Eloquent\Model::getAttribute()
... (Laravel internal calls)

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Additional issue with strict mode

When enabling Laravel’s strict mode (Model::shouldBeStrict()), I encountered errors about missing attributes like translationModel and translationForeignKey in translation models.

To temporarily fix these, I had to add the following manually to my main model:

protected string $translationModel = \App\Models\CourseTranslation::class;
protected string $translationForeignKey = 'course_id';

However, this should ideally be handled inside the package to avoid manual fixes in every project.

Could you please provide an approximate timeline for when these strict mode compatibility issues will be officially resolved? It would help us plan and confidently use strict mode with laravel-translatable.

[Gummibeer]

laravel-translatable/src/Translatable/Translatable.php

Line 173 in 9841b07

return parent::getAttribute($key);

For all the properties I think we would have to use some explicit property_exists() checks instead of the fallback __get logic and null check.
Right now they are listed as @property-read and use the everything returns null by default logic instead of some real property checks. But as we don't want them to be Laravel attributes anyway but just real PHP properties or fallback logic we can switch to property_exists() which could also increase performance sLiGHtlY as we don't need to go in the Laravel model attribute rabbit hole.

[Gummibeer]

#442 was an attempt to fix but with way too many side changes and stuff. I would also prefer property_exists() over isset() as isset() is too broad.