Fix enum hydration when fetching partial results

[michnovka]

This is the first attempt to fix the issue #9622

[michnovka]

I suggest the following:

in AbstractHydrator use:

case isset($cacheKeyInfo['isScalar']):
    $type = $cacheKeyInfo['type'];

    if (isset($cacheKeyInfo['enumType'])) {
        $value = $type->convertToPHPEnumValue($value, $this->_platform, $cacheKeyInfo['enumType']);
    } else {
        $value = $type->convertToPHPValue($value, $this->_platform);
    }

    $rowData['scalars'][$fieldName] = $value;

    break;

And in DBAL extend the Type class:

    /**
     * Converts a value from its database representation to its PHP enum representation
     * of its type
     *
     * @param mixed $value The value to convert
     * @param AbstractPlatform $platform
     * @param string $enumType
     * @return BackedEnum
     * @throws ConversionException
     */
    public function convertToPHPEnumValue($value, AbstractPlatform $platform, $enumType)
    {
        try {
            return $enumType::from($value);
        }catch(ValueError $error){
            throw new ConversionException("Cannot convert value to PHP enum", 0, $error);
        }
    }

This will work well for most types. I will overload the method in those, where it would be problematic, such as SimpleArrayType.

If somebody wants to have PHP enum support in their type, they can overload this method too.

There is no BC break.

[beberlei]

This is a good fix given our current data structures.

It shows though that our reflection and type apis are not the best abstraction anymore.

I was thinking about something new for ORM 3 but had no time sofar. For 2.x we can use this approach

[michnovka]

@beberlei So can I make the DBAL PR? I need it merged there before I can finish this in ORM, otherwise tests will fail.

[beberlei]

I am reviewing on mobile phone, the current patch looks like it can work without dbal changes? The fix must be orm only

[michnovka]

The current fix has the limitations which I described, it will ONLY work with string type. If we use SimpleArrayType or any custom type with enumType (which is supported and even present in our tests) it will throw. I have described above a solution which requires Type change but allows fix for ALL types, including giving ability to custom types to make a fix the way they want.

[beberlei]

Couldnt you switch over the scalar type inside the enumMappibngs case and reimplement the simple array case? We are already in workaround mode here so local patching is fine. Add a comment that it reimplements the ReflectionEnumPriperty code there

[michnovka]

I can and it was my first approach, but we will fix only these 2 cases. I realized enumType can be used on any type, so that solution was allowing that. So workaround it is?

[michnovka]

This is ready for merge. @beberlei please review

[beberlei]

Go from overall implementation pov, havent reviewed style and other non functional requirements.

[derrabus]

Thank you @michnovka!