Allow elements from other namespaces

[malarzm]

This is how we should ideally allow extensions to be combined with ODM's schema. Sadly, this does not work and it seems work on extensions' maintainers is needed anyway :(

Cross referencing doctrine-extensions/DoctrineExtensions#2318

[greg0ire]

Sadly, this does not work and it seems work on extensions' maintainers is needed anyway

I think it's because the extension xsd file is not provided here:

mongodb-odm/lib/Doctrine/ODM/MongoDB/Mapping/Driver/XmlDriver.php

Lines 718 to 720 in c9b7f6b

	if (! $document->schemaValidate(__DIR__ . '/../../../../../../doctrine-mongo-mapping.xsd')) {
	throw MappingException::xmlMappingFileInvalid($filename, $this->formatErrors(libxml_get_errors()));
	}

You'd have to let the user provide a schema combining both xsd files as in doctrine/orm#11117 (comment)

[malarzm]

@greg0ire thanks for all the pointers! I'll prolly join you in doctrine/orm#11123 soon