Serialize new custom fields

[anikachurilova]

Support new custom fields: journal, thesis, notes, meeting, imprint in existing serializers:

• csl
• datacite
• dcat
• dublincore
• geojson
• iiif
• marcxml
• bibtex

[alejandromumo]

We have two options in the RFC:

• Per field:

class RandomFieldExporter:

    def marc_xml():
        ...

    def datacitev43():
        ...


RDM_CUSTOM_FIELDS = {
    "experiment": VocabularyCF(
        ...
        export=RandomFieldExporter()
    ),
}

• Per export format

class MARCXmlExporter:

    def experiments():
        ...

class DublinCoreExporter:

    def experiments():
        ...


RDM_CUSTOM_FIELDS = {
    "experiment": VocabularyCF(
        ...
        export=dict(
            marc=MARCXmlExporter(),
            dublin_core=DublinCoreExporter()
        )
    ),
}

This topic needs a discussion before the implementation

[alejandromumo]

We decided to prototype the option per field, using journal as an example.

The prototype should also contain multiple formats to have a grasp on how this can grow in terms of code

[alejandromumo]

For the prototype, we decided to add a generic post dump pipeline (can also be implemented for other stages of the serialization, e.g. pre_dump).

Each serializer then adds the steps it sees fit for its own needs (e.g. DataciteJsonSerializer adds custom fields processors, each defining its own post_dump implementation). Everything is then "merged" together (with many caveats)

[alejandromumo]

To showcase the implemented mechanism I implemented journal serialization into DataCite, MarcXML and DublinCore. Also added DublinCore serializartion for meeting.

Since this will scale up (e.g. X formats * Y custom fields), I will first wait until the post_dump/pre_dump mechanism is fully approved before implementing all the combinations of custom fields and formats.

Thus, I am moving the issue to review