Add resolveXsiType

[akayumeru]

Add a xsi:type resolve method to the Element Context Enhancer in order to properly resolve types for XML generation

Q	A
Type	improvement
BC Break	yes
Fixed issues	phpro/soap-client#539

Summary

To resolve type for xsi:type attribute I needed a value that I am passing to Encoder. That's why I suggesting to add resolveXsiType method in Element Context Enhancer interface.

Usage example

    public function resolveXsiType(Context $context, mixed $value): Context
    {
        $xsd = Xmlns::xsd()->value();
        $resolvedType = null;

        if (is_a($value, DateTime::class)) {
            $resolvedType = $context->type->copy('dateTime')
                ->withXmlTypeName('dateTime')
                ->withXmlNamespaceName($context->namespaces->lookupNameFromNamespace($xsd)->unwrap())
                ->withXmlNamespace($xsd);
        }

        if (is_a($value, Date::class)) {
            $resolvedType = $context->type->copy('date')
                ->withXmlTypeName('date')
                ->withXmlNamespaceName($context->namespaces->lookupNameFromNamespace($xsd)->unwrap())
                ->withXmlNamespace($xsd);
        }

        if ($resolvedType !== null) {
            return $context->withType($resolvedType);
        }

        return $context;
    }

[akayumeru]

I added usage example

[veewee]

Thanks for the PR.

I'm not sure it's a good idea to always force people to implement resolveXsiType when enhancing the element encoders context.

Will play around with it to see if there are better alternatives once I'm back from vacation in a few weeks.

[veewee]

@LazyTechwork

I've provided an alternative PR to solve this issue:
#22

I'm not completely sure it's the best way to go. Care to take a look at it and play around with it?
Any feedback is welcome.

[veewee]

Thanks for the PR and pointing out the issue.
I decided to go for #22