/// <summary>
/// Returns true if the given singletonInstanceBehavior is one of the values that allows a caller to assign the Instance directly.
/// <para/>AutoConstructIfNeeded, ManuallyAssign_MayBeNull, ManuallyAssign_MustBeNonNull
/// </summary>
public static bool InstanceCanBeManuallyAssignedBehavior(this SingletonInstanceBehavior singletonInstanceBehavior)
{
return(singletonInstanceBehavior == SingletonInstanceBehavior.AutoConstructIfNeeded ||
singletonInstanceBehavior == SingletonInstanceBehavior.ManuallyAssign_MayBeNull ||
singletonInstanceBehavior == SingletonInstanceBehavior.ManuallyAssign_MustBeNonNull
);
}
/// <summary>
/// Base constructor. Constructs a SingletonHelperBase with client given behavior and InstanceConstructionDelegate.
/// Resulting SingletonHelper may be used as IDisposable and supports use with SingletonObjectTypes that are either IDisposable or not.
/// </summary>
/// <param name="behavior">Defines the Instance property construction and use behavior: AutoConsruct, ManuallyAssign_MustBeNonNull or ManuallyAssign_MayBeNull</param>
/// <param name="instanceConstructionDelegate">Gives the delegate that will be invoked to construct the instance object if/when that is required. Must not be null if the given behavior may AutoConstruct the instance.</param>
/// <exception cref="SingletonException">thrown if instanceConstructionDelegate is null and the given behavior may attempt to AutoConstruct the instance.</exception>
public SingletonHelperBase(SingletonInstanceBehavior behavior, InstanceConstructionDelegate instanceConstructionDelegate)
{
Behavior = behavior;
this.instanceConstructionDelegate = instanceConstructionDelegate;
if (instanceConstructionDelegate == null && behavior.IsAutoConstructBehavior())
{
throw new SingletonException("Attempt to use a null instanceConstructionDelegate with {0} behavior".CheckedFormat(behavior));
}
}
/// <summary>
/// Base constructor. Constructs a SingletonHelper with client given behavior.
/// Resulting SingletonHelper may be used as IDisposable and supports use with SingletonObjectTypes that are either IDisposable or not.
/// </summary>
/// <param name="behavior">Defines the Instance property construction and use behavior: AutoConsruct, ManuallyAssign_MustBeNonNull or ManuallyAssign_MayBeNull</param>
public SingletonHelper(SingletonInstanceBehavior behavior)
: base(behavior)
{
}
/// <summary>
/// Returns true if the singletonInstanceBehavior allows the Instance to be set to null.
/// <para/>ManuallyAssign_MayBeNull, AutoConstructIfNeeded
/// </summary>
public static bool DoesBehaviorPermitInstanceToBeSetToNull(this SingletonInstanceBehavior singletonInstanceBehavior)
{
return(singletonInstanceBehavior == SingletonInstanceBehavior.ManuallyAssign_MayBeNull || singletonInstanceBehavior == SingletonInstanceBehavior.AutoConstructIfNeeded);
}
/// <summary>
/// Returns true if the singletonInstanceBehavior allows the Instance getter to return null.
/// <para/>ManuallyAssign_MayBeNull
/// </summary>
public static bool DoesBehaviorPermitInstanceGetterToReturnNull(this SingletonInstanceBehavior singletonInstanceBehavior)
{
return(singletonInstanceBehavior == SingletonInstanceBehavior.ManuallyAssign_MayBeNull);
}
/// <summary>
/// Returns true if the given singletonInstanceBehavior that may attempt to construct the instance when first required.
/// <para/>AutoConstruct, AutoConstructIfNeeded
/// </summary>
public static bool IsAutoConstructBehavior(this SingletonInstanceBehavior singletonInstanceBehavior)
{
return(singletonInstanceBehavior == SingletonInstanceBehavior.AutoConstruct ||
singletonInstanceBehavior == SingletonInstanceBehavior.AutoConstructIfNeeded
);
}