private async Task <string> TrySaveFlags(FeatureFlagsViewModel model, string contentId)
{
var flags = new FeatureFlags(
model.Features.ToDictionary(f => f.Name, f => f.Status),
model.Flights.ToDictionary(f => f.Name, f => f.AsFlight()));
var result = await _storage.TrySaveAsync(flags, contentId);
switch (result)
{
case FeatureFlagSaveResult.Ok:
// The flags have been persisted. Refresh this instance's cache immediately.
await _cache.RefreshAsync();
var refreshSeconds = _config.FeatureFlagsRefreshInterval.TotalSeconds;
TempData["Message"] = $"Your feature flags have been saved! It may take up to {refreshSeconds} seconds for this change to propagate everywhere.";
return(null);
case FeatureFlagSaveResult.Conflict:
return("Your changes were not applied as the feature flags were modified by someone else. Please reload the page and try again.");
default:
return($"Unknown save result '{result}'.");
}
}
public async Task <ActionResult> Index(FeatureFlagsViewModel model)
{
if (ModelState.IsValid)
{
var result = await _storage.TrySaveAsync(model.Flags, model.ContentId);
switch (result.Type)
{
case FeatureFlagSaveResultType.Ok:
// The flags have been persisted. Refresh this instance's cache immediately.
await _cache.RefreshAsync();
var refreshSeconds = _config.FeatureFlagsRefreshInterval.TotalSeconds;
TempData["Message"] = $"Your feature flags have been saved! It may take up to {refreshSeconds} seconds for this change to propagate everywhere.";
return(Redirect(Url.Action(actionName: "Index", controllerName: "Features")));
case FeatureFlagSaveResultType.Conflict:
TempData["ErrorMessage"] = "Your changes were not applied as the feature flags were modified by someone else. " +
"Please reload the page and try again.";
break;
case FeatureFlagSaveResultType.Invalid:
ModelState.AddModelError(nameof(model.Flags), $"Invalid flags: {result.Message}");
break;
default:
TempData["ErrorMessage"] = $"Unknown save result '{result}': {result.Message}.";
break;
}
}
return(View(model));
}
private static void StartFeatureFlags(IFeatureFlagCacheService featureFlags)
{
// Try to load the feature flags once at startup.
try
{
featureFlags.RefreshAsync().Wait();
}
catch (Exception)
{
}
// Continuously refresh the feature flags in the background.
HostingEnvironment.QueueBackgroundWorkItem(featureFlags.RunAsync);
}
