"read-only" public catalog

[Galen Charlton]

It would be occasionally useful to have a "read-only" mode for the Evergreen public catalog that would prevent patrons from making any changes or require that the Pg database allow writes.

One way this might operate is by disabling the ability to log into the public catalog; another way might be to allow logging in but disable the ability to

- place and manage hold requests
- renew loans
- pay fines
- update lists

A specific use case is allowing a read-only catalog to operate against a replica database during a major Evergreen upgrade.

Evergreen master

[Jeff Davis (jdavis-sitka)]

I think disallowing login altogether is a simpler, clearer approach. It would be confusing for patrons to be able to login but be unable to perform any actions, and there's a risk that their account info would be out-of-date (e.g. if the replica database is an older backup or if they've checked items in/out via offline circ during the read-only period). "Sorry, you can't login right now" is easier to understand. I bet it's also easier to implement.

Action trigger-based OPAC functions like "Email Record Details" should also be disabled in the UI in read-only mode. You need write access to the database to create a/t events, and read-only mode needs to work without db write access.

FWIW, I've tried running EG as-is with read-only database access. Basic search functions work just fine, and you can add titles to a basket (but see above about disabling action trigger-based functions). You can login to the OPAC, but trying to place a hold results in an internal server error, and updating personal info/preferences fails but you get an "account successfully updated" message.