/// <summary>
/// Creates the target object and appropriate interception when one of the Injector's Create methods is called.
/// </summary>
/// <remarks>Implementors can override this method if they need to control creation of the target object.
/// The base class implementation calls
/// <see cref="System.Activator.CreateInstance(Type, object[])"/> and then defers the interception
/// to <see cref="PolicyInjector.DoWrap(object, Type, PolicySet)"/>.</remarks>
/// <param name="typeToCreate"><see cref="System.Type"/> of target object to create.</param>
/// <param name="typeToReturn">Type of the reference to return.</param>
/// <param name="policiesForThisType">Policy set specific to typeToReturn.</param>
/// <param name="arguments">Constructor parameters.</param>
/// <returns>The new target object.</returns>
protected virtual object DoCreate(Type typeToCreate, Type typeToReturn, PolicySet policiesForThisType, object[] arguments)
{
object target = Activator.CreateInstance(typeToCreate, arguments);
return(DoWrap(target, typeToReturn, policiesForThisType));
}
/// <summary> /// Wraps the given instance in a proxy with interception hooked up if it /// is required by policy. If not required, returns the unwrapped instance. /// </summary> /// <param name="instance">object to wrap.</param> /// <param name="typeToReturn">Type of the reference to return.</param> /// <param name="policiesForThisType">Policy set specific to typeToReturn.</param> /// <returns>The object with policy added.</returns> protected abstract object DoWrap(object instance, Type typeToReturn, PolicySet policiesForThisType);
/// <summary>
/// Creates a new <see cref="RemotingPolicyInjector" /> with the
/// given <see cref="PolicySet"/>.
/// </summary>
/// <param name="policies"><see cref="PolicySet"/> to use when
/// creating object or wrapping existing ones.</param>
public PolicyInjector(PolicySet policies)
{
this.policies = policies;
}
/// <summary>
/// Creates a new <see cref="RemotingPolicyInjector" /> with an
/// empty <see cref="PolicySet" />.
/// </summary>
public PolicyInjector()
{
policies = new PolicySet();
}
/// <summary>
/// Checks to see if the given policy set requires interception on targets that it is applied to.
/// </summary>
/// <param name="policies">Policy set to check.</param>
/// <returns>True if policy set contains anything, false if not.</returns>
protected static bool PolicyRequiresInterception(PolicySet policies)
{
return(policies.Count > 0);
}
private PolicyInjector CreateDefaultInjectorWithGivenPolicySet(PolicySet policies)
{
return(new RemotingPolicyInjector(policies));
}