available covers not being retrieved from OpenLibrary for some titles

[Galen Charlton]

In (some?) cases where there are more than one work record for a given ISBN in the Open Library's database, using the OL Read API to request links to covers can fail to bring up an edition that has a cover.

A good example of this is ISBN 9264023607.

https://openlibrary.org/search?q=9264023607 - OL search results with two editions in the hitlist

http://openlibrary.org/api/volumes/brief/json/isbn:9264023607 - invocation of the Read API that brings up an edition *without* links to the cover image

BUT

http://openlibrary.org/api/volumes/brief/json/isbn_10:9264023607 - invocation of the Read API that does bring up an edition with links to the cover image

Evergreen master

[Galen Charlton (gmc)]

An experimental patch is available at the tip of the user/gmcharlt/lp1306823_fetch_more_covers_from_ol branch in the working/Evergreen repository:

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/gmcharlt/lp1306823_fetch_more_covers_from_ol

A few notes about this:

- It's entirely possible that this works only by accident
- A better approach may be using the Read API's multiple option and scanning through the results to find the first edition that has a cover link
- The cover image URLs returned by the Read API look like this - https://covers.openlibrary.org/b/id/3343096-L.jpg. This may be a problem: these are Covers API URLs, and the OL documentation says that they are rate-limited to a maximum of 100 requests every five minutes. This suggests that the Read API may not be suitable as a way of getting past that limit for cover images.

[Galen Charlton (gmc)]

As Dan Scott points out, https://github.com/internetarchive/openlibrary/issues/15 implies that the rate limit has been removed (though the API documentation has not been updated to reflect that).

[Josh Stompro (u-launchpad-stompro-org)]

Galen, I think the example you included was fixed, I don't see any problem between the "isbn:" and "isbn_10:" examples above. They both include the cover art links when I open them. Do you have another example that still shows the problem?