| 1 | const DEFAULT_LANGUAGE = 'en'
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| 2 |
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| 3 | /**
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| 4 | * @example
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| 5 | * var labels = {'en': 'Temperature', 'de': 'Temperatur'}
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| 6 | * var tag = CovUtils.getLanguageTag(labels, 'en-GB')
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| 7 | * // tag == 'en'
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| 8 | *
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| 9 | * @param {object} map An object that maps language tags to strings.
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| 10 | * @param {string} [preferredLanguage='en'] The preferred language as a language tag, e.g. 'de'.
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| 11 | * @return {string} The best matched language tag of the input map.
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| 12 | * If no match was found then this is an arbitrary tag of the map.
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| 13 | */
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| 14 | export function getLanguageTag (map, preferredLanguage = DEFAULT_LANGUAGE) {
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| 15 | if (preferredLanguage in map) {
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| 16 | return preferredLanguage
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| 17 | }
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| 18 |
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| 19 | // cut off any subtags following the language subtag and try to find a match
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| 20 | let prefTag = preferredLanguage.split('-')[0]
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| 21 | let matches = Object.keys(map).filter(tag => prefTag === tag.split('-')[0])
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| 22 | if (matches.length) {
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| 23 | return matches[0]
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| 24 | }
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| 25 |
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| 26 | // no luck, return a random tag
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| 27 | return Object.keys(map)[0]
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| 28 | }
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| 29 |
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| 30 | /**
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| 31 | * @example
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| 32 | * var labels = {'en': 'Temperature', 'de': 'Temperatur'}
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| 33 | * var label = CovUtils.getLanguageString(labels, 'en-GB')
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| 34 | * // label == 'Temperature'
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| 35 | *
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| 36 | * @param {object} map An object that maps language tags to strings.
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| 37 | * @param {string} [preferredLanguage='en'] The preferred language as a language tag, e.g. 'de'.
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| 38 | * @return {string} The string within the input map whose language tag best matched.
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| 39 | * If no match was found then this is an arbitrary string of the map.
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| 40 | */
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| 41 | export function getLanguageString (map, preferredLanguage = DEFAULT_LANGUAGE) {
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| 42 | let tag = getLanguageTag(map, preferredLanguage)
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| 43 | return map[tag]
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| 44 | }
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