Using "Build column from other column" custom-column type

[HFC3]

Is there any documentation on how to do this? Searching for "Build" returns no hits.

I'm assuming this type is supposed to let you have a new column X be assigned a value based on the value of existing column Y.

But;
1. I used a search filter "format:MOBI" to test this - column was filled with the template "format:MOBI" literal.
2. Where do you indicate what value is assigned?

Say I want to assign a new Yes/No column "MOBI" to Y (checked) if the a book includes a version in MOBI format (search filter "format:MOBI")

Thanks (yet) again

[chaley]

That kind of column uses a template to generate it's value. There are many threads about using templates. There are calibre doc sections on the same topic, for example the template language docs.

[PeterT]

See http://manual.calibre-ebook.com/template_lang.html

Try this:

{:'in_list(approximate_formats(), ',' , 'MOBI',  'Y',  '')'}

approximate_formats() – return a comma-separated list of formats that at one point were associated with the book. There is no guarantee that the list is correct, although it probably is. This function can be called in template program mode using the template {:'approximate_formats()'}. Note that format names are always uppercase, as in EPUB.

in_list(separator, pattern, found_val, not_found_val) – interpret the field as a list of items separated by separator, comparing the pattern against each value in the list. If the pattern matches a value, return found_val, otherwise return not_found_val.

Also see the documentation for Using functions in templates - template program mode

[HFC3]

Thanks PeterT.

I wish the Calibre manual would include links to all the sub-manuals I'm finding for the "neat" features. It's hard to know they're there unless you accidentally find a link in a thread.

I did try searching for this in the >F1< help, but (of course), I used search words ("build", "custom column", etc) that didn't include "template".