Every map translated its own chrome but left the basemap's country, city
and street names in the style default (English on Mapbox, Latin + native
on OpenFreeMap) in all eleven locales. A reader in Arabic saw an Arabic
legend over an English map.
library/maps/localize-labels.js uses each engine's supported mechanism:
- Mapbox: map.setLanguage(lang). It also localizes the Standard style's
IMPORTED basemap, which a layer rewrite cannot reach.
- MapLibre: basemap symbol layers point at
['coalesce', name:<lang>, name:latin, name]. English restores each
layer's original expression, re-captured on every style load so a theme
switch never restores the previous style's labels.
Only layers whose text-field reads an OSM name field are touched. A
plugin's own label layers (zone titles, group names) are never rewritten.
useMapInstance applies it on every style.load and when the reader's
language changes (ProfileLoader's 'lang', else profile-config locale, else
?lang / <html lang>). The Prayer Walk Planner drops its private copy for
the shared one.
Measured on the Prayer Progress map, ar/zh/ru/hi:
- Mapbox getLanguage() == locale in all four.
- MapLibre: 13/14 symbol layers localized, and the plugin's own label
layer untouched.
Read in the Arabic screenshots: القاهرة, الإسكندرية, السويس, الأردن on
both engines. check:gallery-embed (+ :maplibre) and
check:prayer-walk-planner pass. The shared change reaches all 11 bundles
that compile initializeMap, and all are rebuilt here. check:shared-reached
marker basemap-labels-localized: 10/10 consumers.
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