Fix Plugin extendModel

[ndunks]

Fix property translatable is not merged when $translatePlugin->extendModel is called in multiple times.

I need to add custom field on CMS Page with translation too (in my plugin). I was using backend.form.extendFields event to add meta_keywords field with type mltext. This code to add translation to it.

/** @var \Winter\Translate\Plugin */
$translatePlugin =  PluginManager::instance()->findByIdentifier("Winter.Translate", true);

 /** @param \Cms\Classes\Page $model */
Page::extend(function ($model) use ($translatePlugin, $translatable) {
    $translatePlugin->extendModel($model, 'page', ['meta_keywords']);
});

But it remove translation to other fields title, url, etc.. After I debug it, I found that exetendModel function is not merging the translatable attributes. Current code:

public function extendModel($model, string $type, array $translatableAttributes = [])
{
    if (!$model->propertyExists('translatable')) {
        $model->addDynamicProperty('translatable', $translatableAttributes);
    } else {
        $model->translatable = array_merge($model->translatable, $translatableAttributes);
    }

if (dynamic) property already exists, because was called in my plugin. Then this code fail to merge the attributes.
Because the getter function will prioritize the attribute from dynamic properties, but the setter will set on instance attributes directly.

Leaving condition like this:

Theres 2 property, in instance attributes and in dynamic properties with different values.

This PR fixt that, with setting the attributes in dynamic property

[mjauvin]

this method is not meant to be used elsewhere, it's just a helper in the Plugin class to avoid repeating ourselves... just extend the Page model in the usual way in your plugin.

[ndunks]

How to extend "translatable" property in usual way? Can you give me example?

[mjauvin]

What version of WinterCms do you use?

[ndunks]

I checked by command: php artisan winter:version

This the result:

*** Detecting Winter CMS build...
*** Detected Winter CMS build 1.2.6.

[mjauvin]

There were changes in winter 1.2.5 that affects the way dynamic properties get created because of php 8.2+ deprecation (https://php.watch/versions/8.2/dynamic-properties-deprecated)

So we're now using winter dynamic properties but there may still be unexpected issues related to this.

Are you adding translatable items before or after the translatable property has been added to the CMS page by the translate plugin?

[mjauvin]

Here are the commits that changed this:

wintercms/storm@dce5c40

wintercms/storm@e03b13c

[ndunks]

Page:extend callback in my plugin called before translatable plugin.

[ndunks]

I think we need to add another test cases for dynamic attribute, such as merging array values

[mjauvin]

I think we need to add another test cases for dynamic attribute, such as merging array values

you're right. if you can do this as part of this PR, that would be awesome.

[ndunks]

I will try it, but I can start it on the next week, probably in the monday (GMT+7).