CODEWITHSUNDEEP
c#-4.0scopeparent-child
heltonbiker
heltonbiker

Reputation: 27605

Make property in parent object visible to any of its contained objects

I have a class CalculationManager which is instantiated by a BackgroundWorker and as such has a CancellationRequested property.

This CalculationManager has an Execute() method which instantiates some different Calculation private classes with their own Execute() methods which by their turn might or might not instantiate some SubCalculation private classes, in sort of a "work breakdown structure" fashion where each subclass implements a part of a sequential calculation.

What I need to do is to make every of these classes to check, inside the loops of their Execute() methods (which are different from one another) if some "global" CancellationRequested has been set to true. I put "global" in quotes because this property would be in the scope of the topmost CalculationManager class.

So, question is:

How can I make a property in a class visible to every (possibly nested) of its children?

or put down another way:

How can I make a class check for a property in the "root object" of its parent hierarchy? (well, not quite, since CalculationManager will also have a parent, but you got the general idea.

I would like to use some sort of AttachedProperty, but these classes are domain objects inside a class library, having nothing to do with WPF or XAML and such.

Upvotes: 0

Views: 78

Answers (1)

Ondrej Svejdar
Ondrej Svejdar

Reputation: 22074

Something like this ?

public interface IInjectable {
  ICancelStatus Status { get; }
}
public interface ICancelStatus {
  bool CancellationRequested { get; }
}
public class CalculationManager {
  private IInjectable _injectable;
  private SubCalculation _sub;
  public CalculationManager(IInjectable injectable) {
    _injectable = injectable;
    _sub = new SubCalculation(injectable);
  }
  public void Execute() {}
}
public class SubCalculation {
  private IInjectable _injectable;
  public SubCalculation(IInjectable injectable) {
    _injectable = injectable;
  }
}
private class CancelStatus : ICancelStatus {
  public bool CancellationRequested { get; set;}
}

var status = new CancelStatus();
var manager = new CalculationManager(status);
manager.Execute();

// once you set status.CancellationRequested it will be immediatly visible to all
// classes into which you've injected the IInjectable instance

Upvotes: 1

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