Handle http schemas

[ilovan]

Decision:

1. CWRC will add proxies for the established TEI customizations (https://trello.com/c/hy4CcGsk)
2. For non-TEI schemas and otehr TEI customizations,
   a. provide more detailed error message (i.e. why the schema is failing)
   b. provide documentation (re saving and referencing copies of the schemas in GitHub repos)
   c. ensure the Git-Writer Git server supports referencing the GitHub schemas

Archived description:

In the revamped Git-Writer, users can load any xml document, with any schema declared, including http schemas which are currently not supported by CWRC-Writer. We need to either
find

• a way for CWRC Writer to read non https schemas, or
• a way to automatically add a proxy for the http schemas when used in Git-Writer.

We discussed this problem with James and Andrew multiple times in the past and it looks like the former is not a viable solution.

Re the latter, would it be possible to have a setup where:

1. Git-Writer would check the schema of an uploaded document and if http identified, send a call to the CWRC server
2. On the CWRC Server, the call from GitWriter would trigger a script that would create an on-the fly proxy and pass it back to Git-Writer
3. GitWriter would use the proxy while the document is open and send another call to the CWRC server when the document is closed to remove the proxy

Do you think this would be doable, @jefferya ?

[ilovan]

FYI, @ajmacdonald :

EpiDoc proxy: https://cwrc.ca/epidoc/schema/latest/tei-epidoc.rng on this card

[ajmacdonald]

Related discussion: cwrc/DEPRECATED-CWRC-Writer#386

[ilovan]

Remaining to do:

For non-TEI schemas and other TEI customizations that either:

1. don't have https

or

2. have https but don't have CORS enabled

• provide more detailed error message (i.e. why the schema is failing)
• provide documentation (re saving and referencing copies of the schemas in GitHub repos)
• ensure the Git-Writer Git server supports referencing the GitHub schemas