@kartotherian/babel
v1.0.1-wmf.0
Published
Tile source to support multilingual maps
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@kartotherian/babel
Tile source to restructure vector PBFs for multilingual usecases, such as convert a single JSON object into multiple key/values, or to replace all language key/value names with a single one.
Usage examples
Tile is generated with 'name_' field set a JSON-encoded key-value object. Babel can be used to convert that tile to a tile, with each value in the object becoming a tag of its own, e.g. 'name_en', 'name_fr', ... . Also, babel can be used to replace multiple 'name_lang' tags with a single 'name_' tag right before rendering it, choosing the best language based on the fallback rules, but only if it is different from the 'name' tag.
# Process tiles from 'gen' source, expanding json string into multiple tags
json2tags:
uri: json2tags://
params:
source: {ref: gen}
tag: name # optional, 'name' is the default
# Process tiles from 'store' source, replacing all 'name_*' tags with a single 'name' tag
babel:
uri: babel://
params:
source: {ref: store}
# optional, 'name' is the default
tag: name
# optional, used by default if no 'lang' code is passed to getAsync()
defaultLanguage: 'en'
# optional map of fallback values. Can be a json file or an object value
languageMap: '/my/path/fallback.json'
# -- OR --
languageMap:
en: ['fr', 'es', 'de']
ru: ['be']
Language resolution
For babel://
, the language of the name_
is chosen based on these rules:
getAsync({z,x,y, lang:'xx')
:
name_xx
- Use explicitly set fallbacks from the languageMap
- Use any
name_yy-Script
whereScript
is the script ofxx
. E.g. iflang=ru
, pick anylang_yy-Cyrl
. - If
xx
uses the Latin script, use anyname_zz_rm
name
Scripts
Babel gets the CLDR defined script name (Latn, Cyrl, ... ) based on the language code. It also uses a few overrides from the overrides.json
. This file should be updated with any language IDs found in OSM data.