XML deserialization with JMS Serializer

Question

I am trying to deserialize this very simple XML:

<?xml version="1.0" encoding="utf-8"?>
<root>
    <namespace>foo</namespace>
    <resource>bar</resource>
    <description>baz</description>
    <arguments>
        <argument>
            <name>foo</name>
            <type>string</type>
            <description>foo</description>
        </argument>
        <argument>
            <name>bar</name>
            <type>string</type>
            <description>bar</description>
        </argument>
    </arguments>
</root>

No matter what I try I can not deserialize arguments element into array or ArrayCollection or any kind of collection as the array always ends up empty.

/**
 * @Type("array<Model\Argument>")
 */
private $arguments;

/**
 * @Type("ArrayCollection<Model\Argument>")
 */
private $arguments;

Both end up as empty array. So I tried creating a separate object for arguments

Thus the original property ends up as

/**
 * @Type("Model\Arguments")
 */
private $arguments;

and the class

class Arguments {
    /**
     * @Type("array<App\Blueprint\Model\Argument>")
     */
    private $arguments;

    /**
     * @return mixed
     */
    public function getArguments() {
        return $this->arguments;
    }

    /**
     * @param mixed $arguments
     */
    public function setArguments($arguments) {
        $this->arguments = $arguments;
    }
}

the array is still empty. But, when I change the type to @Type("App\Blueprint\Model\Argument") I will get the correct object, though only the first one.

When I try to register a deserialization handler I am unable to modify it because it comes as SimpleXmlElement and then I will get It is not yet possible to assign complex types to properties warning...

EDIT

For now I managed to solve it in a stupid way:

$registry->registerHandler(
    'deserialization',
    'Model\Arguments',
    'xml',
    function(XmlDeserializationVisitor $visitor, $data, array $type, DeserializationContext $context) {
        $arguments = [];
        foreach($data->children() as $child) {
            $arguments[] = SerializerBuilder::create()
                ->build()
                ->deserialize($child->asXML(), 'Model\Argument', 'xml');
        }

        return $arguments;
    }
);

Just leaving it out here if someone has a better solution.

Answer 1

You were quite close. You have to define two separate classes.

/**
 * @Type("Model\Arguments")
 */
public $arguments;

/**
 * @Type("array<Model\Argument>")
 * @XmlList(inline = true, entry = "argument")
 */
public $argument;

Note the @XmlList property in the Argument class. You can remove the getter and setter too!