URL Fields

The schema, ui_schema, and form_data properties for any forms describe independently constrained documents, which doesn’t work well with most JSON schema tools.

For a complex form, it can make sense to keep documents in separate files, generate them on the fly, or rely on a form user’s browser to fetch them at run-time.

Remote URLs

Instead of local files, the schema, ui_schema, and form_data options may be given as URLs starting with http:// or https://. These will be passed unchanged to the underlying form.

This is useful for reusing assets hosted somewhere else, or which use complex relative $refs. However, if the linked files move, become unavailable, or otherwise cannot be reached due to browser limitations, a form will not be rendered.

Python

The py: prefix denotes an importable python module, which must be available at CLI/Sphinx run time, either as an installed python package on sys.path, or by hacking the PYTHONPATH environment variable.

These may return either a concrete value or callable which returns:

• a JSON-compatible python dictionary which will be encoded as a normalized JSON file

• a URL string