/// <summary>
/// Helper method
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
private string Localize(string name)
{
// Just in case 2 threads with 2 different cultures invoked the same localizer concurrently
// (It probably never happens, but I have seen signs that some MVC libraries might do that)
lock (_translationsLock)
{
// This is to workaround the behavior of certain MVC libraries
// which seem to re-use the same IStringLocalizer across multiple requests,
// even though the current UI culture is a scoped value and the localizer is transient
if (_translations == null || (_culture ?? CultureInfo.CurrentUICulture).Name != _translations.CultureName)
{
_translations = _factory.GetTranslations(_culture);
}
// Go over the dictionaries one by one and return the first hit
foreach (var translationDictionary in _translations.InDescendingOrderOfPrecedence())
{
if (translationDictionary != null && translationDictionary.ContainsKey(name))
{
return(translationDictionary[name]);
}
}
// If all is a miss, return the name as is, forgiveness here is a virtue.
return(name);
}
}
public CascadingTranslations GetTranslations(CultureInfo culture = null)
{
culture = culture ?? CultureInfo.CurrentUICulture; // Current UI culture by default
string defaultUICulture = _config["DefaultUICulture"];
string specificUICulture = culture.Name;
string neutralUICulture = culture.IsNeutralCulture ? specificUICulture : culture.Parent.Name;
// We refresh the cache once per request, and we track this using a flag in the HTTP Context object
string flag = specificUICulture;
var isUpdated = (bool?)(_httpContextAccessor.HttpContext == null ? false : _httpContextAccessor.HttpContext.Items[flag]);
if (!(isUpdated ?? false))
{
// The list of cultures to update;
List <string> culturesToFreshenUp = new List <string>
{
// Update localization cache for the default application culture
defaultUICulture
};
// Update localization cache for the current request culture, if different
if (specificUICulture != defaultUICulture)
{
culturesToFreshenUp.Add(specificUICulture);
}
// Update localization cache for the neutral request culture, if not already neutral
if (neutralUICulture != specificUICulture)
{
culturesToFreshenUp.Add(neutralUICulture);
}
// Update the local cache, or distributed cache timestamp if need be
EnsureFreshnessOfCaches(culturesToFreshenUp.ToArray());
// Set the flag, to prevent another cache refresh within the same scope
// Note: this is thread safe, since only one thread at a time will get
// a copy of the HTTP context, since it is scoped per request
if (_httpContextAccessor.HttpContext != null)
{
_httpContextAccessor.HttpContext.Items[flag] = true;
}
}
_localCache.TryGetValue(CacheKey(specificUICulture), out LocalCacheItem specificCache);
_localCache.TryGetValue(CacheKey(neutralUICulture), out LocalCacheItem neutralCache);
_localCache.TryGetValue(CacheKey(defaultUICulture), out LocalCacheItem defaultCache);
var result = new CascadingTranslations
{
CultureName = specificUICulture,
SpecificTranslations = specificCache?.Translations,
NeutralTranslations = neutralCache?.Translations,
DefaultTranslations = defaultCache?.Translations,
};
// Return the translations
return(result);
}