This is a subtask of issue #2836.
Since the PDF extraction is quite complex, errors/exceptions can arise at different levels:
- Grobit itself in the extraction step.
- During the model conversion. (Which is currently implemented using the BibTeX parser.) E.g., due to missing or incompatible fields.
- During enrichment using the BibSonomy database.
Errors need to be collected for each post and presented to the user. See how it is currently done in the BibTeXParser, when a user posts BibTeX that contains several entries.