Bug (solved): metadata downloader returning files without content for formats: nquads and jsonld

[RaimiSol]

At the endpoint /ontologies/:acronym the buttons N-Triple and JSON-LD trigger downloads for files with content "undefined".

I solved the issue by modifying the line 96 in metadata_downloader_controller.js

Using chrome devtools the problem showing up was that the condition subJson["URI"] !== undefined` didn't catched null values the consequences were:

• missing @ id property of jsonldObject
• error in jsonld.toRDF with message: 'Invalid JSON-LD syntax; \"@ id\" value must a string'

[syphax-bouazzouni]

OK, can you please provide us with a PR with your fix?

[syphax-bouazzouni]

To reproduce

1. Go to https://agroportal.lirmm.fr/ontologies/SIREN
2. Click on the button N-Triple

3. See the downloaded file, with only undefined written instead for the ontology metadata

Proposed fix

See https://github.com/ontoportal-lirmm/bioportal_web_ui/pull/256, @SirineMhedhbi clean and review the code