/// <summary>
/// Performs controller action pre-procesing to ensure that at least one of the specified features are enabled.
/// </summary>
/// <param name="context">The context of the MVC action.</param>
/// <param name="next">The action delegate.</param>
/// <returns>Returns a task representing the action execution unit of work.</returns>
public override async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
var fm = context.HttpContext.RequestServices.GetRequiredService <IFeatureManagerSnapshot>();
//
// Enabled state is determined by either 'any' or 'all' features being enabled.
bool enabled = RequirementType == RequirementType.All ?
await Features.All(async feature => await fm.IsEnabledAsync(feature).ConfigureAwait(false)) :
await Features.Any(async feature => await fm.IsEnabledAsync(feature).ConfigureAwait(false));
if (enabled)
{
await next().ConfigureAwait(false);
}
else
{
IDisabledFeaturesHandler disabledFeaturesHandler = context.HttpContext.RequestServices.GetService <IDisabledFeaturesHandler>() ?? new NotFoundDisabledFeaturesHandler();
await disabledFeaturesHandler.HandleDisabledFeatures(Features, context).ConfigureAwait(false);
}
}
/// <summary>
/// Registers a disabled feature handler. This will be invoked for MVC actions that require a feature that is not enabled.
/// </summary>
/// <param name="builder">The feature management builder.</param>
/// <param name="disabledFeaturesHandler">The disabled feature handler.</param>
/// <returns>The feature management builder.</returns>
public static IFeatureManagementBuilder UseDisabledFeaturesHandler(this IFeatureManagementBuilder builder, IDisabledFeaturesHandler disabledFeaturesHandler)
{
builder.Services.AddSingleton <IDisabledFeaturesHandler>(disabledFeaturesHandler ?? throw new ArgumentNullException(nameof(disabledFeaturesHandler)));
return(builder);
}
