Context
Citoid can not read PDFs but can extract DOIs from URLs. This is already working in a lot of cases. Let's figure out how that can be improved so that users who try to make a citation out of an "unsupported" PDF type can still get a meaningful result back from Citoid based on the DOI lookup.
Tasks
- Look into how DOIs are extracted from URLS
- See if that mechanism can be improved
- Figure out how to log the successful attempts (would be good to have something other than HTTP status code 200, Log level INFO to be able to distinguish the PDF URLs that went through a DOI lookup vs those that were working because the server responds with HTML)
- Make sure existing workflows are still working the same
Testing
PDF URLs with DOI for testing:
| URL | Issue | |
| https://www.eucass.eu/doi/EUCASS2025-590.pdf | Incomplete DOI in URL | not solvable |
| https://www.3af-spacepropulsion.com/images/DOI/SPC2026/DocFinal-527-2526-(1).pdf | No DOI in URL | not solvable |
| https://academic.oup.com/smr/advance-article-pdf/doi/10.1093/sxmrev/qeaf057/64711993/qeaf057.pdf | Unclear where DOI ends | might be solvable by checking multiple DOIs |
| https://www.frontiersin.org/articles/10.3389/fpsyg.2010.00001/pdf | Unclear where DOI ends | could be solvable by cutting of /pdf or .pdf from the URL |
- More examples of PDF URLs that fail in Citoid and have a DOI: see here (internal document)