Originally Posted by meme
It won't work, at least at the moment.
Testing this (and remembering to send the books with the new section/subsection/kindle columns to the device) shows me that the Calibre metadata is updated with the general column information.
Unfortunately, when using a custom column built from other columns with a template, Calibre only saves the template definition in the metadata.calibre file in the field 'display', and leaves the 'value' field blank. The plugin uses the 'value' field as the collection name.
Its possible that I could call the template parsing code to determine what the value should be - that wouldn't be for a while. Alternatively it could be considered a bug in Calibre - it should write out the value of the column as its known at the time it saves the metadata. Something we can ask Kovid.
I suspect there might be a similar issue with enumerated values - I haven't tested these and I can see that use the same display field to hold the template.
Can you tell me how to write some code, attached to a button, to fill in the value field of a column, even if it is hardcoded, based on a concatenation of the values in the two other columns since I do not know python. I know it is too much to ask, and has nothing to do with your plugin, but could you please please help. It will make life sooooo simple.