[Koha-devel] Multilingual label printing in Koha (praise be to Bywater!)

[dcook at prosentient.com.au]

Hi all,

I had a problem where I couldn't print Chinese and English on barcode labels
using Koha's built-in Label Creator, since it uses individual font files and
I couldn't find a free and open individual font that supports both European
and Chinese scripts.

Fortunately, I recalled that Kyle @ ByWater Solutions created this plugin:
https://github.com/bywatersolutions/koha-plugin-label-maker. It uses HTML
and CSS to generate labels in the browser, and the browser is already
capable of using multiple different fonts to support multiple different
scripts. The plugin did a great job of rendering barcodes with both Chinese
and English written on them! Thanks, Bywater Solutions, for saving the day!

--
Nerdy thoughts:

If I look at the "Computed" styles in the F12 tools in Chrome on Windows 10,
it says the English is rendered using the "Times New Roman" font, and it
says that the Chinese is rendered using the "Microsoft YaHei" font. If I do
the same thing in Microsoft Word, the English is in "Calibri" and the
Chinese is in "DengXian". If you read
https://fonts.google.com/noto/use#how-are-noto-fonts-organized it says "If
you have text in multiple languages that use different scripts, either the
app or the person who typesets the text needs to switch between the
different fonts accordingly."

I'm not an expert on fonts, so I'm not sure what would be involved with
getting Koha's PDF libraries to use different fonts for different scripts. I
don't know how Chrome and Word detect that they need to use a different
font. I don't know if it's a map of Unicode codepoints to existing font
mappings, or if it iterates through a list of fallbacks, or what. 

I probably won't go too far down this rabbit hole, since the ByWater Koha
Plugin solved my immediate use case, but it's an interesting topic, and this
is a major limitation with Koha's Label Creator, so we might want to think
about a change in the future...

David Cook
Senior Software Engineer
Prosentient Systems
Suite 7.03
6a Glen St
Milsons Point NSW 2061
Australia

Office: 02 9212 0899
Online: 02 8005 0595