New collection of schemas for Enhanced Gateway

Modifying a schema

The below is a walkthrough of the steps required to make a change to an existing schema, by way of an example. Other changes will require slightly different steps.

In this example, we wish to modify the type of a field (accessibility.formatAndStandards.conformsTo) in the HDRUK 2.2.1 schema.

Modify schema files

The schema definition in hdr_schemata/models/HDRUK/2.2.1/schema.json is generated from the contents of hdr_schemata/models/HDRUK/v2_2_1, building upon the contents of previous versions. `v2_1_2 is the "base model" all current schemas are derived from.

We create a new FormatAndStandards.py in the v2_2_1 directory, with the boilerplate taken from v2_1_2/FormatAndStandards.py. Into this file we import

from hdr_schemata.models.HDRUK.v2_2_0 import (
    FormatAndStandards as BaseFormatAndStandards,
)

Note that this is from the previous version, which itself imports from v2_1_2. Ensure that the v2_1_2/__init__.py correctly exports the class.

Overload the class, using the imported class as base:

class FormatAndStandards(BaseFormatAndStandards):
    conformsTo: Optional[List[StandardisedDataModels]] = Field(
        ..., **an.vocabularyEncodingScheme.__dict__
    )

Now import this file into v2_2_1/Accessibility.py, and overload the field there with the new type:

class Accessibility(BaseAccessibility):
    access: Access = Field(..., description=an.description, title=an.title)

    formatAndStandards: Optional[FormatAndStandards] = Field(
        None,
        title=an.formatAndStandards.title,
        description=an.formatAndStandards.description,
    )

The changes to the schema are now ready to process.

Create schema json

Run python create_json_schema.py. This will modify the contents of hdr_schemata/models/HDRUK/2.2.1/schema.json as appropriate. You may need to install the repo as a local package:

pip install -e .

Update docs

Finally, update the Markdown docs with:

python hdr_schemata/utils/create_markdown.py

to generate the Markdown in docs/. After merging, this will be available at https://hdruk.github.io/schemata-2/.