Relations plugin for model builder

Relation data type

The relation data type marks part of the metadata that will be filled with a related object.

Example usage - part of dataset model:

primary-article:
    type:  relation
    name:  article
    model: article
    keys: ['metadata.title', 'metadata.authors']

The element "primary-article" will be connected to the article record. The record class and properties will be taken from the "article" model that is registered in "oarepo_models" entrypoint.

When returned to the user/serialized to ES, it will take the title and author fields from the related model and copy them into the primary-article field.

It will automatically generate the following schema:

will generate:

// schema
{
    "primary-article": {
        "type": "object",
        "properties": {
            "id": {"type": "string"},
            "@v": {"type": "string"},
            "title": {},     // copied from registered article model
            "authors": {}    // copied from registered article model
        }
    }
}

class Record:
    # ...
    relations = MultiRelationsField(
        article=PIDRelation(                # "name" from above
            "...primary-article",           # path inside the dataset model
            "keys": ['metadata.title', 'metadata.authors'],   # copied keys
            pid_field: Article.pid          # resolved model name and PID field
        )
    )

All arguments:

primary-article:
    type: relation
    name: ...
    model: ...
    keys: [...]
    model-class:
    relation-classes:
        list: PIDListRelation
        nested: PIDNestedListRelation
        single: PIDRelation
    relation-class:
    relation-args:
        attrs: []
        keys: []
        _value_key_suffix: id
        _clear_empty: true
        cache_key:
        value_check:
        pid_field: model-class.pid
    imports:
    - import: invenio_records_resources.records.system_fields.relations.PIDRelation
      alias: PIDRelation

Internal relations

Sometimes it you might want to reference part of your document for indexing purposes etc. and not split the document into two records. For these, internal relations can be used:

properties:
    metadata:
        properties:
            obj{}:
                ^id: anchor-obj
                test: keyword
                id: keyword

On object/array item, define the "id" field containing your "symbolic" name of the target of the relation. Then the definition of the relation will look like:

properties:
    metadata:
        properties:
            internal-ref:
                type: relation
                model: "#anchor-obj"
                keys: [id, test]

Supported relations

See referrer.yaml for a list of supported relations.