Using IF THEN ELSE in a Calibre Save Template

[sylvandale]

Hi. I'm hoping for some help please in configuring my Calibre Save Template, and using IF THEN ELSE logic.

I have a custom 'Genre' hierarchical column to organise everything in my library. I got this idea from here many years ago I think, so I assume people will know the kind of thing. Examples of the structure are e.g.
fiction
fiction.crime
fiction.thriller
fiction.thriller.historical
travel
travel.usa
travel.usa.ca
etc.

For a long time I have happily used a nice template, also taken from this forum (thanks!), which breaks down the genre into folders and subfolders based on the "." separator. This is the argument:

"{#genre:'re_group($,"([^.]+)\.","[[$]]/")'}/{authors}/{series}/{title} - {authors}"

So e.g. John Grisham's Camino Winds, with Genre 'Fiction.Thriller' is sorted to 'Fiction/Thriller/John Grisham/Camino Winds - John Grisham'. [There is also an optional "Series" subfolder level, if the series field is populated.]

However, I don't pretend to understand this syntax properly. It just works and I'm very grateful.

What I have realised is that for all Fiction books I want to have the {authors} level subfolder, but for all other types of books I want a sort which does not use that subfolder. With Fiction, I tend to know what author I am looking for, but with other types that's not usually the case.

So, in simple terms, what I think I am after is something like:

IF
genre is fiction.*
THEN
{#genre:'re_group($,"([^.]+)\.","[[$]]/")'}/{authors}/{series}/{title} - {authors}
ELSE
{#genre:'re_group($,"([^.]+)\.","[[$]]/")'}/{series}/{title} - {authors}

The '*' above is meant to be the usual wildcard expression, as there may be no additional genre sub-categories or one sub-category or two or more.

Can anybody help put that into Calibre-speak please?

Many thanks

[chaley]

It isn't quite clear what you want but I think this is it. This template requires the latest version of calibre (5.40).

program:
# Isolate the first genre. If there is never more than one then use
#	g = re($#genre, '\.', '/');
	g = re(sublist($#genre, 0, 1, ','), '\.', '/');
	
# Test if the genre starts with 'fiction'.
	if "^fiction" in g then
		g & '/' & $authors & '/' & test($series, $series & '/', '') & $title & ' - ' & $authors

	else
		g & '/' & test($series, $series & '/', '') & $title & ' - ' & $authors
	fi

EDIT: Rereading your post it might be that you want to check for a prefix of "fiction.", not "fiction". If so then change the "if "^fiction" line to be

	if "^fiction/" in g then

NB: Use a slash because periods have already been converted to slashes, and the anchor '^' causes the check to be "starts with".

[sylvandale]

Absolutely brilliant, Works like a charm. Many, many thanks.