Copying of multi-instance nested elements generates invalid JSON-LD

[martinjoconnor]

If we have an element that contains a multi-instance element and we make a copy of the nested element in the Metadata Editor then the generated nested element instance does not contain an @id field.

For example, assume we have an element named My Element that contains a nested multi-instance Address element and put My Element in a template as a single instance element:

If we click on the clone icon the make a new Address and then click Save we get the following JSON-LD:

 "Address": [
      {
        "@context": {
          "Address 1": "https://schema.metadatacenter.org/properties/b4be7ce9-bb5d-4633-8e94-d82a49310aa3",
          "Address 2": "https://schema.metadatacenter.org/properties/8edb39e5-92ab-4144-8294-1b7f0bf2b982",
          "City": "https://schema.metadatacenter.org/properties/ed3c76b3-5c48-4ccd-968e-2d44590f37e1"
        },
        "Address 1": {          "@value": "A1"        },
        "Address 2": {          "@value": null        },
        "City": {          "@value": "C1"        },
        "@id": "https://repo.metadatacenter.org/template-element-instances/237f1de4-c0f2-4e19-8204-7e7e0104570b"
      },
      {
        "@context": {
          "Address 1": "https://schema.metadatacenter.org/properties/b4be7ce9-bb5d-4633-8e94-d82a49310aa3",
          "Address 2": "https://schema.metadatacenter.org/properties/8edb39e5-92ab-4144-8294-1b7f0bf2b982",
          "City": "https://schema.metadatacenter.org/properties/ed3c76b3-5c48-4ccd-968e-2d44590f37e1"
        },
        "Address 1": {          "@value": "A1"        },
        "Address 2": {          "@value": null        },
        "City": {          "@value": "C1"        }
      }
    ],

The second Address instance does not have an @id, which is invalid.

Oddly, we can still save the instance. However, when we attempt to copy this instance in the desktop the copy fails with a validation error because of the missing @id

Also, this does not happen with a single level of nesting, e.g., if the Address element is directly placed as a multi-instance element at the top level of the template.