quick fix for Link header handling for json-ld

[datadavev]

Fixes RDFLib/rdflib-jsonld#85

Proposed Changes

• Add support for handling Link header responses

PR is a minimal implementation to get rdflib-jsonld to work with schema.org remote context reference.

TBD:

• Can multiple Link headers returned (e.g. to reference different content types)?
• Do other RDF formats leverage the Link header in HTTP response is specific to JSON-LD?

[coveralls]

Coverage decreased (-0.03%) to 75.762% when pulling 89989b7 on datadavev:issue_rdflib-jsonld_85 into c050f27 on RDFLib:master.

[ashleysommer]

Hi @datadavev
Is the cgi import and empty <B> fix related to the json-ld link header fix? Looks like you might've pushed that commit into the wrong branch.

[datadavev]

Hi @datadavev
Is the cgi import and empty <B> fix related to the json-ld link header fix? Looks like you might've pushed that commit into the wrong branch.

Ah, indeed - I'll adjust. Thanks

[nicholascar]

Hi @datadavev, there are two issues with this PR:

1. JSON-LD isn't yet in RDFlib core, although we hope it will be soon, so that this PR won't apply for many cases. If we were to pass it, it would need to do a better job of knowing that JSON-LD was enable, not just looking for the format "json-ld".
2. Link headers in HTTP can be used for all kinds of things, e.g. description of related resources, not just redirects, so your Link header parsing function needs a lot more information to only get redirects.

Sorry but I'm going to have to close this. Please feel free to re-issue it after we've included JSON-LD in RDFlib core (Coming soon!) and after having a bit more of a go at parsing Link headers a bit more carefully.