Google Cloud Translation

Google Cloud Translation translates text between languages and can detect the source language automatically. The gRPC API is exposed through the google.cloud.translation.v3.TranslationService service, reached at translate.googleapis.com:443 over TLS, with the main methods TranslateText, DetectLanguage and GetSupportedLanguages.

Requests are built with TsgcGRPCTranslationTranslateTextRequest, which sets Parent (projects/<id>/locations/global), Contents, SourceLanguageCode and TargetLanguageCode. The reply is returned in TsgcGRPCTranslationTranslateTextResponse, whose Translations contain the TranslatedText.

The example below authenticates with a service-account JWT, wires a TsgcGRPCClient over a TsgcHTTP2Client to the Translation host, sets the authorization Bearer metadata and calls TranslateText to translate "Hello, world!" from en to es:

    oHTTP2 := TsgcHTTP2Client.Create(nil);
    oHTTP2.Host := 'translate.googleapis.com';
    oHTTP2.Port := 443;
    oHTTP2.TLS := True;

    oGRPC := TsgcGRPCClient.Create(nil);
    oGRPC.Client := oHTTP2;

    // service-account JWT authentication
    oGRPC.GoogleCloudOptions.JWT.KeyFile := 'service-account.json';
    oGRPC.GoogleCloudOptions.JWT.API_Endpoint := 'https://translate.googleapis.com/';
    oGRPC.DefaultMetadata.AddValue('authorization', 'Bearer ' + oGRPC.GoogleCloudOptions.JWT.Token);

    // build the typed request and call the method
    oRequest := TsgcGRPCTranslationTranslateTextRequest.Create;
    try
      oRequest.Parent := 'projects/my-project-id/locations/global';
      oRequest.Contents.Add('Hello, world!');
      oRequest.SourceLanguageCode := 'en';
      oRequest.TargetLanguageCode := 'es';
      oResponse := oGRPC.Call('google.cloud.translation.v3.TranslationService', 'TranslateText', oRequest.ToBytes);
      ShowMessage(oResponse.DataString);
    finally
      oRequest.Free;
    end;