State Change Handlers

In situations where we have a long running service or recurring task, we need to be able to stop and start them

IFeatureStateService

IFeatureStateService allows registering Action handlers which will be called when the feature changes state.

Due to the nature of what we're controling, only deterministic states are considered valid, so the state change will only trigger for AlwaysOn and off. Any other type of rollout will be considered off.

* Support for additional deterministic states will be added in the future

Feature Flags around Hangfire Jobs

var featureStateService = app.Services.GetRequiredService<IFeatureStateService>();
featureStateService.WhenFeatureTurnsOn(FeatureFlags.HourlyJob, () =>
{
    //start a service or job
    RecurringJob.AddOrUpdate<ITestRecurringJob>("Hourly job", s => s.RunAsync(), Cron.Hourly());
});

featureStateService.WhenFeatureTurnsOff(FeatureFlags.HourlyJob, () =>
{
    //stop a service or job
    RecurringJob.RemoveIfExists("Hourly job");
});