Add support for custom validation messages and attributes when using property morphable

[bentleyo]

Custom validation messages and attribute names don't work properly when using property-morphable data at the moment. They build messages from the base class, not the morphed one, even when the morph attributes are provided.

This PR fixes that by making the DataValidationMessagesAndAttributesResolver class aware of property-morphable data.

There is a section of code I added that is now repeated in both:

• DataValidationMessagesAndAttributesResolver
• DataValidationRulesResolver

Not sure if it should be moved somewhere shared to avoid this duplication.

The code in question:

        if ($dataClass->isAbstract && $dataClass->propertyMorphable) {
            $payload = $path->isRoot()
                ? $fullPayload
                : Arr::get($fullPayload, $path->get(), []);

            $morphedClass = $this->dataMorphClassResolver->execute(
                $dataClass,
                [$payload],
            );

            $dataClass = $morphedClass
                ? $this->dataConfig->getDataClass($morphedClass)
                : $dataClass;
        }

[ncphillips]

We're also running into this issue so I'm very excited for this fix. We make use of polymorphic collections in a couple places and ranging their error messages has been really frustrating.

Edit: If anyone else needs this, you can copy bentley's class into your own app and bind it to the container:

[ncphillips]

Actually, this doesn't seem to be a complete fix @bentleyo

It works if I do MyPolymorphicData::validate([ ... ]) but it does not work if I have a parent data object with a Collection<MyPolymorphicData> property on it.

Will investigate more later

[ncphillips]

Okay, I got a test that reproduced the issue I was seeing, and updated the code to make that test pass.

Opened a PR into this branch @bentleyo

https://github.com/bentleyo/laravel-data/pull/2/files

[bentleyo]

Thanks @ncphillips I'll have a look this evening!

[ncphillips]

We've found a couple other problematic cases.

Case 1: Nullable Polymorphic Child

The first is when an object has a nullable polymoprhic child and it happens to be null:

class Vehicle {}
class Car extends Vehicle {}
class Truck extends Vehicle {}

class Garage {
  vehicle?: Vehicle
}

Note: I opened a PR into this branch to try and fix it, but I've just realized it's failing. bentleyo#3

Case 2: Polymorphic Children of Non-Polymorpch Items in a Collection

The second case is more annoying. We changed our data structure to avoid the problem, but it's still worth mentioning.

If you have an array of non-polymorphic objects, but those objects themselves have a polymorphic child, then laravel-data will not check any further down. For example, if I had a Region that contained various garages:

class Region {
  garages: Garage[]
}

This would fail to use the custom validation messages/attributes for the Vehicles in the Garage