Referencing to components in external JSON files is missing

[byjg]

I think the referencing to components in external JSON files is missing in this list, like described in "4.7.23 Reference Object" of the specification.
Or did I miss something and the feature is there?

Originally posted by @froschdesign in https://github.com/_render_node/MDIzOlB1bGxSZXF1ZXN0UmV2aWV3VGhyZWFkMjU2MzI3NTMxOnYy/pull_request_review_threads/discussion

[froschdesign]

This library can help to read reference objects in external JSON or YAML files: php-openapi

Usage

$openapi = cebe\openapi\Reader::readFromJsonFile(realpath('openapi.json'));

https://github.com/cebe/php-openapi#reading-api-description-files