Project Description

A C# .NET Library to simplify M-V-VM (Model, View, Viewmodel) programming. Includes base implementations for observable objects (property change notifications), weak delegates/events and asynchronous and synchronized events, efficient event handling, disposable base, etc.

Nuget: PM> Install-Package SharpObservation

Summary

Sharp Observation fulfills the following goals:

• A high-performance implementation for exposing events:
  • A performance optimized EventHandlerList reduces memory footprint of event objects - objects retains a very small footprint when events aren't hooked up, and are performant when event handlers are attached.
  • Type safe / signature safe pattern for raising events.

Read more about implementing efficient event-raising classes

• A base implementation of the observable pattern, including:
  • INotifyPropertyChanged and INotifyPropertyChanging implementation.
  • A richer PropertyChangedEventArgs which enable undo scenarios.
  • A bypass mechanism to property change optimize performance when no listeners are attached.
  • An IsNotifcationActive property which expresses whether any listeners are attached.
  • An IsNotifcationActiveChanged event which fires when IsNotifcationActive changes.
  • A helper type to simplified implementation of CLR properties.

Read more about observable objects

• Extension methods to convert delegates to become:
  • Synchronized - i.e. the delegate raises it's target on an appropriate thread
  • Asynchronous - i.e. the delegate does not wait for the target to complete before returning.

How to use synchronized events

How to use asynchronous events

• Provides a base implementation of the auto-dispose pattern:
  • all private fields with references to objects are nulled (and optionally disposed) upon disposal.
  • an IsDisposed property, allowing blind callers to detect whether the instance has been disposed.
  • ThrowIfDisposed() for guarding against method calls after disposal.

• A helper class - DisposeHelper - which generates efficient IL code for disposing of objects:
  • Correctly implements the IDisposable pattern.
  • If the instance is being disposed (as opposed to finalized), then it disposes of any objects referenced by fields, and those fields are assigned null.
  • Nulls references to large objects (like arrays).
  • If the class contains a boolean field named "isDisposed" (case insensitive), then the field is set to true.
  • If the class contains an Action field named "throwIfDisposed" (case insensitive), then the delegate is assigned to a method that throws ObjectDisposedException.
  • If (and only if) the class contains a finalizer, then GC.SurpressFinalize is called to remove the object from the finalization queue.