Column for characters in universe

[CAIArchive]

created a column built from other columns, behaves like tags. I'm not great at code, but so far I have:

program:
		if (ifempty(field('#chars'), ''))
		then list_union(field('#chars'),(first_non_empty(field('#universe'), field('series'), field('title'))), '.') fi

Its almost correct except I cant figure out how to make it apply the part starting with (first_non_empty) to item with the possible list that is (chars). The end goal is, I can type main characters names into (chars) and calibre will automagically put the highest level category followed by a '.' followed by each char name into the charsort column. The above catches the first category and populates correctly, all the rest of the chars are just the name itself.

goal would be: universe.char1, universe.char2, etc

What am I missing? Or is it not possible?

Any help would be appreciated

[chaley]

Moderator Notice
Moved to its own thread for better visibility

[chaley]

I think this does what you want. The trick is to loop through the characters. Your template operated on only the first character in the list.

program:
	result = '';
	if $#chars then
# Loop through the characters adding the universe prefix
		for char in '#chars':
			result = strcat(result, first_non_empty($#universe, $series, $title), '.', char, ',')
		rof;
# Clean up the list, adding spaces and removing the trailing comma
		result = list_union(result, '', ',')
	fi;
	result

[chaley]

This is a more efficient version of the template, making use of the fact that the universe prefix doesn't change for a given book.

program:
	result = '';
	if $#chars then
# The universe name is a constant for each book. Compute it once for efficiency
		prefix = strcat(result, first_non_empty($#universe, $series, $title), '.');

# Loop through the characters adding the universe prefix to the character
# and adding a trailing comma
		for char in '#chars':
			result = strcat(result, prefix, char, ',')
		rof;

# Clean up the list, adding spaces and removing the trailing comma
		result = list_union(result, '', ',')
	fi;
	result

[CAIArchive]

Thank you so much. That is absolutely what I was trying to do. The explanations helped also. Thank you again