parent ancestry— wikilisp-formatted stored list of ancestors for
parent, if any.
parent2 ancestry— wikilisp-formatted stored list of ancestors for
parent2, if any.
parents— wikilisp-formatted list of parents of
ancestry— wikilisp-formatted stored list of ancestors for
shelf, if any.
If either of the parent lists of ancestors looks wrong — if it's not there, or not properly formatted, or empty, or not in fully sorted ascending order — this shelf doesn't attempt to assess the status of its own ancestors list. Those problems are the parent's responsibility, not this shelf's; but this shelf does then encourage the user to investigate the status of the parent (if it exists; if the parent doesn't exist, there will be a separate notice generated elsewhere, and that should be dealt with first). If the parental ancestors lists look okay, the ancestors list for the current shelf is computed by merging parents list and parental ancestors lists, and compared with the stored ancestors list for the current shelf, if any. If the ancestry page for the current shelf needs work, an explanatory is provided with a button for manual editing. A contemplated upgrade would detect availability of dialog and replace the editing button with one for a dialog-based assistant.