Mapping file uploads with Doctrine MongoDB ODM

Photo.mongodb.xml

<?xml version="1.0" encoding="UTF-8"?>
<doctrine-mongo-mapping xmlns="http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"
                        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                        xsi:schemaLocation="http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping
                http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd">

    <document name="Acme\Domain\Model\Photo\Photo" collection="photos">
        <field fieldName="_id" id="true" />      
        <field fieldName="galleryId" type="string" />
        <field fieldName="description" type="string" />
        <reference-one field="photoFile" target-document="Acme\Domain\Model\Photo\PhotoFile"
                       simple="true" orphan-removal="true">
            <cascade>
                <persist/>
            </cascade>
        </reference-one>
    </document>

</doctrine-mongo-mapping>

PhotoFile.mongodb.xml

<?xml version="1.0" encoding="UTF-8"?>
<doctrine-mongo-mapping xmlns="http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping"
                        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                        xsi:schemaLocation="http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping
                http://doctrine-project.org/schemas/odm/doctrine-mongo-mapping.xsd">

    <document name="Acme\Domain\Model\Photo\PhotoFile" collection="photos.files">
        <field fieldName="id" id="true" />
        <field fieldName="file" type="file"/>
        <field fieldName="filename" type="string"/>
        <field fieldName="mimeType" type="string"/>
        <field fieldName="uploadDate" type="string"/>
        <field fieldName="length" type="string"/>
        <field fieldName="chunkSize" type="string"/>
        <field fieldName="md5" type="string"/>
    </document>
</doctrine-mongo-mapping>

Came from:

• https://twitter.com/webdevilopers/status/974626234419372032

When mapping and uploading files w/ #MongoDB and #DoctrineODM I currently split the actual "file" from my "#domainmodel" in order to add some extra properties to the latter only. Do you prefer too split them too or keep all the info inside one Document?