/// <summary>
/// Registers the given <see cref="EventsContext"/> as a service in the <see cref="IServiceCollection" />.
/// </summary>
/// <typeparam name="T">The type of context to be registered.</typeparam>
/// <param name="services">The <see cref="IServiceCollection"/> to register with.</param>
/// <param name="optionsBuilder">
/// <para>
/// An action to configure the <see cref="EventsContextOptions" /> for the context. This provides an
/// alternative to performing configuration of the context by overriding the
/// <see cref="EventsContext.OnConfiguring" /> method in your derived context.
/// </para>
/// <para>
/// If an action is supplied here, the <see cref="EventsContext.OnConfiguring" /> method will still be run if it has
/// been overridden on the derived context. <see cref="EventsContext.OnConfiguring" /> configuration will be applied
/// in addition to configuration performed here.
/// </para>
/// </param>
/// <returns>The original <see cref="IServiceCollection"/>.</returns>
public static IServiceCollection AddEventsContext <T>(
this IServiceCollection services,
Action <EventsContextOptions> optionsBuilder
)
where T : EventsContext
{
if (optionsBuilder == null)
{
throw new ArgumentNullException(nameof(optionsBuilder));
}
var options = new EventsContextOptions();
optionsBuilder(options);
services.TryAddScoped <EventsScope>();
var eventsContextFactory = ActivatorUtilities.CreateFactory(
typeof(T),
new[] { typeof(EventsContextOptions) }
);
var eventsContextFactoryArgs = new object[] { options };
services.AddSingleton(x => (T)eventsContextFactory(x, eventsContextFactoryArgs));
services.AddScoped <IScopedAppServiceProvider, AppServiceProvider>();
services.AddSingleton <IRootAppServiceProvider, AppServiceProvider>();
services.AddTransient(x => x.GetRequiredService <T>().GetEventReceiversHostedService());
return(services);
}
/// <summary>
/// Creates a new <see cref="EventsContext"/>
/// </summary>
/// <param name="options">The options for this context.</param>
/// <param name="rootAppServiceProvider">The application root service provider.</param>
protected EventsContext(
EventsContextOptions options,
IRootAppServiceProvider rootAppServiceProvider
)
{
_internalEventsContext = new Lazy <InternalEventsContext>(() => new InternalEventsContext(
options,
OnConfiguring,
OnBuildingPipelines,
OnBuildingSubscriptions,
rootAppServiceProvider,
this
), LazyThreadSafetyMode.ExecutionAndPublication);
}
/// <summary>
/// Override this method to override the options supplied in the constructor.
/// The resulting configuration may be cached and re-used during the entire lifespan of the context.
/// </summary>
/// <remarks>The default implementation of this method does nothing.</remarks>
/// <param name="options">The options of the <see cref="EventsContext"/>.</param>
protected virtual void OnConfiguring(EventsContextOptions options)
{
}