"Autozeroing" Certain Metadata

[Jaws]

I've looked for solutions to this one, but maybe my search-fu isn't up to this forum's needs...

In any event, there are some metadata fields that I would like to fill with a blank or a zero on bringing a book into Calibre. For example:

I really, REALLY don't care what some other rating system has given a book (especially since most of the "ratings" imported are way, way off — the downside of crowdsourcing for academic books). Neither do I care about the (usually inaccurate, and certainly not up to a research library's standards!) "tags" and "IDs"; in fact, I manually remove all of this data, especially for "later edition" books (like, say, any edition of a book from the 1950s that includes a "new cringe-inducing-celebrity foreword"). I'm most annoyed by the "date" field, because "import into Calibre" date is not "acquisition date" or anything else meaningful to me... or for other purposes.

I've been unable to find a way to selectively by field ensure that the irrelevant metadata is zeroed out or blank, but still import other relevant metadata (like the author's name, year of "publication," etc.). For example, the best I've been able to do with the useless "Date" field is limit it to the day of the month, a simple number that's less of a pain to swipe away by hand. Every time. And there's apparently nothing to be done with "rating" or "tags" or "IDs"... unless I'm missing something.

Am I missing something? Or is this worthy of a "metadata extension"?

[ownedbycats]

If the metadata is included in the books:
Preferences > Adding books > Reading metadata > Uncheck 'Read metadata from file contents.' If the filename is something like 43423842824343.epub, you'll have to enter all that info manually.

If the metadata is downloaded:
Preferences > Metadata Download > Metadata fields to download > Uncheck the ones you don't want.

For tags specifically, check out the tag mapper.

For the date field specifically you can't set a default for that. You can use the bulk metadata editor to clear it from multiple books at once though.

[chaley]

You could use the Action Chains plugin to do the changes with one keypress. Create a chain of actions that modify metadata however you want. Assign a keyboard shortcut to the chain. To use it, select the books you want to zap then execute the chain with the shortcut.

[ownedbycats]

Note that the Action Chains plugin currently doesn't allow for nulling a date field. You can probably use a template for that though.

[chaley]

Originally Posted by ownedbycats

Note that the Action Chains plugin currently doesn't allow for nulling a date field. You can probably use a template for that though.

Single Field Edit offers "Clear value" as a choice. You would use a template if you wanted different values depending on other metadata.

[ownedbycats]

I forgot about clear value. disregard my earlier post.

[capink]

I just tested that in Action Chains, and the "Clear Value" does work only for custom date columns, but not for timestamp column.

Apparently setting the value of timestamp to None has no effect, unlike what happens with other custom date columns.

I've never had a need to clear the timestamp, so never tested this and thought it would work the same. Calibre intentionally (probably for a good reason) makes it hard to null the timestamp column. You cannot do it in library view and even in search and replace it is not present.

Will look into this for next release.

Edit: You cannot null it using a template as well.

[chaley]

Never mind ...

[capink]

A new version of the action chains plugin that fixes the "Clear value" for the standard date column is now released. The update should be announced by calibre within an hour.

[ownedbycats]

Kovid once mentioned the timestamp field as being important for some reason, though I don't understand why as I thought it was all attached to the book ID.

[capink]

Yes I would guess it is that way for a good reason. I did not like having an option that says "Clear Value" that would not work as expected, so I had two options:

• Correct the behavior to match what the option says. That is the option I went for.
• Remove or disable that option (only for standard date columns)

I figured that since Calibre allows removing standard date using the bulk metadata editor, it should not be a problem to offer the same option in the plugin.