tagTranslations: localizedTag() twig function

index.js

@@ -40,6 +40,7 @@ window.onload = function() {
 
   show('gastro/n281657531', function () {})
 
+  tagTranslations.setTagLanguage('de')
   tagTranslations.load('node_modules/openstreetmap-tag-translations', 'de', function (err) {
     if (err) {
       alert('Error loading translations: ' + err)

src/tagTranslations.js

@@ -1,9 +1,17 @@
 var OverpassLayer = require('overpass-layer')
 var translations = null
+var tagLang = null
 
 OverpassLayer.twig.extendFunction('tagTrans', function () {
   return tagTranslationsTrans.apply(this, arguments)
 })
+OverpassLayer.twig.extendFunction('localizedTag', function (tags, id) {
+  if (tagLang && id + ':' + tagLang in tags) {
+    return tags[id + ':' + tagLang]
+  }
+
+  return tags[id]
+})
 
 function tagTranslationsLoad (path, lang, callback) {
   var req = new XMLHttpRequest()
@@ -82,5 +90,8 @@ function tagTranslationsTrans () {
 
 module.exports = {
   load: tagTranslationsLoad,
-  trans: tagTranslationsTrans
+  trans: tagTranslationsTrans,
+  setTagLanguage: function (lang) {
+    tagLang = lang
+  }
 }