If I ingest a Citation or Thesis object but I don't have a PDF that I can include, how can I direct users to access a fulltext version of the article?
If your objects contain a DOI in a MODS Identifier field <identifier type = "doi">, several options become possible. The DOI itself can be linked to externally-hosted articles, but often those articles are behind paywalls - even when open-access versions exist.
To get around this, the Islandora Badges module has a submodule called Islandora oaDOI.
Islandora oaDOI queries the oaDOI.org service, which provides links to free, open-access fulltext versions of articles with DOIs, if they exist. The module creates a block which appears on any objects that (a) do not have a PDF datastrea, and (b) do have a free fulltext link available through oadoi.org, and offers a link for the user to access the fulltext externally.
To use Islandora oaDOI: