translate function

Future<Result<List<TranslationResult>, AzureTranslationError>> translate(List<String> text, { required String key, required String region, String? baseLanguage, required List<String> languages, })

Translates a list of text to one or more languages. key and region must be provided. baseLanguage is an optional base language code, e.g. 'en' or 'fr'. If omitted, it will be detected and each result will include a DetectedLanguage.

Implementation

Future<Result<List<TranslationResult>, AzureTranslationError>> translate(
  List<String> text, {
  required String key,
  required String region,
  String? baseLanguage,
  required List<String> languages,
}) async {
  const endpoint = 'https://api.cognitive.microsofttranslator.com/translate';
  final List<(String, String)> queryParams = [
    ('api-version', AzureTranslation.apiVersion),
    ...languages.map((e) => ('to', e)),
    if (baseLanguage != null) ('from', baseLanguage),
  ];

  final paramString = queryParams.map((e) => '${e.$1}=${e.$2}').join('&');
  final uri = Uri.parse('$endpoint?$paramString');

  final headers = {
    'Ocp-Apim-Subscription-Key': key,
    'Ocp-Apim-Subscription-Region': region,
    'Content-Type': 'application/json',
  };

  final texts = text.map((e) => {'text': e}).toList();

  final res = await http.post(
    uri,
    headers: headers,
    body: jsonEncode(texts),
  );

  if (res.statusCode != 200) {
    return Result.error(AzureTranslationError.fromResponse(res));
  }

  return Result.ok(
    List<TranslationResult>.from(
      (jsonDecode(res.body) as List).indexed.map(
            (e) => TranslationResult.fromJson({
              ...e.$2,
              'text': text[e.$1],
            }),
          ),
    ),
  );
}