Template: Extracting a number from a string

[ownedbycats]

I have two columns, text #kobobookmark and integer #chaptercount.

I'd like to create a new column to keep track of read chapters in a fanfic, e.g. 5/25.

I thought the best way to do that is a GPM template that
a) checks a book is a fanfic, is currently being read, and has something in #kobobookmark to count,
b) extract the number of read chapters from #kobobookmark,
c) display that number next to #chaptercount.

I managed to get the first part working already:

program:
	if 
			$#fanficcat 
		&& 
			$#currentlyreading 
		&& 
			$#kobobookmark
	then
		$#chaptercount
	fi

Unfortunately the implementation of b and c I'm a bit stuck on. The bookmarks are always in a string similar to this:

OEBPS/file0003.xhtml#kobo.1.1

The "0003.xhtml" means that it's currently on chapter 3. What would be the best way to get the number and display it as '3/{#chaptercount} chapters read'?

[davidfor]

You can get that number with regex. The following should return it.

program:
re_group($#kobobookmark, '.*\/file(\d+).*')

I'll let you include it in your template and sort out the formatting

[ownedbycats]

That covers part b). While I tinker to see if I can figure out c), is there a way to strip excess leading 0s?

[davidfor]

The function "format_number" should do it:

program:
format_number(re_group($#kobobookmark, '.*\/file(\d+).*'),'{0:,d}')

[ownedbycats]

I think I'm supposed to use a template() here. Though I syntaxed something wrong because it's dividing the numbers (e.g. in the screenshot, it should be '21/22'). Oops.

program:
	if 
			$#fanficcat 
		&& 
			$#currentlyreading 
		&& 
			$#kobobookmark
	then
		
		template(format_number(re_group($#kobobookmark, '.*\/file(\d+).*'),'{0:,d}')/$$#chaptercount)

	fi

Also, I noticed the current template gave an error if the #kobobookmark value is OEBPS/Cover.xhtml#kobo.1.1. Is there a way to change the $#kobobookmark test to account for that?

[davidfor]

I am fairly sure you don't want "template" there. What you probably want to do is a "strcat". So:

strcat(format_number(re_group($#kobobookmark, '.*\/file(\d+).*'),'{0:,d}'),'/',$$#chaptercount)

For the other part, you could do something like:

current_chapter = 0;
if contains($#kobo_reading_location, 'File','1','0') then
    current_chapter = re_group($#kobobookmark, '.*\/file(\d+).*')
fi;
strcat(format_number(current_chapter,'{0:,d}'),'/',$$#chaptercount);

That should replace the line with the template in it.

[ownedbycats]

That worked, though testing it showed a slight oversight since I tend to pause at the beginning of chapters. I fixed by subtracting by one.

program:
input = $#kobobookmark;
a = re(input, '.*\/file(\d+).*', '\1');


	if 
			$#fanficcat 
		&& 
			$#currentlyreading 
		&& 
			$#kobobookmark
	then
		
		strcat(format_number(subtract(a, 1), '{0:,d}'), '/',$$#chaptercount)

	fi

Though while this tested ok putting it in the column itself made an error about 'a' being an unknown identifier.

[ownedbycats]

I was able to fix it by doing this (for some reason it recognized neither input nor a)

  strcat(format_number(subtract((re($#kobobookmark, '.*\/file(\d+).*', '\1')), 1), '{0:,d}'), '/',$$#chaptercount)

[ownedbycats]

The error I got turned out to be a bug in the column evaluator. chaley is working on it now.