Is there a way to set a default function for getters and setters?

Question

I was wondering if there is a way to set a default function for a getter or a setter. For example, let's say I have this:

public class MyClass
{
    public bool IsDirty {get; private set; } = false;

    private string _property;
    public string Property1 
    { 
        get 
        { 
            return _property1;
        } 
        set
        {
            if (value != _property1)
            {
                _property1 = value;
                IsDirty = true;
            }
        } 
    }
}

I was wondering if there was a way to do something like this:

public class MyClass
{
    public bool IsDirty {get; private set;} = false;

    MyClass.defaultSet = { if (value != !_property1) { _property1 = value; IsDirty = true; } };

    private string _property1;
    public string Property1 { get; set; }

    public string Property2 {get; set;}
    public string Property3 {get; set;}
   //...
}

So that I don't have to do it the first way on this big class I have (~100 properties).

why not extract a method from your setter and call it within every setter? — MakePeaceGreatAgain, Nov 07 '22 at 14:33
@MakePeaceGreatAgain: The name and type of `Property` will change for each property. — Poul Bak, Nov 07 '22 at 14:35
Does this answer your question? [Understanding how PropertyChanged mechanism works (workflow)](https://stackoverflow.com/questions/28043183/understanding-how-propertychanged-mechanism-works-workflow) — Poul Bak, Nov 07 '22 at 14:40
try this answer, https://stackoverflow.com/a/1316417/7364454, it's not possible to work with only a simple set; — Lamp, Nov 07 '22 at 15:09
Sounds like a problem where AOP (Aspect Oriented Programming) may be helpful. Its not build in in C# but something like [postsharp](https://www.postsharp.net/) adds that. — Ralf, Nov 07 '22 at 15:33

score 2 · Answer 1 · answered Nov 07 '22 at 15:10

You can reduce the noise by using a helper method like this

private void Set<T>(ref T field, T value)
{
  if (!Equals(value, field))
  {
    field = value;
    IsDirty = true;
  }
}

Then you can write:

public string Property1
{
  get => _property1;
  set => Set(ref _property1, value);
}

score 1 · Accepted Answer · answered Nov 07 '22 at 14:54

No, this doesn't exist, for several reasons:

Not every property is going to be a string, so this would need to correctly handle integers, DateTimes, Decimal, etc
Primitive value types are bad enough, but then start throwing in things like Tuples, complex classes (where changing a class member is still get operation on the property itself!), delegates, etc
If you reference a property by it's own name, you're creating a circular reference that will cause a StackOverflowException.
Not every property is going to use the same Property name, so that part of the method is different. You'd need another keyword or argument to the set method.
You need a way to exempt the someBool / IsDirty property.

Thanks man, fast and professional! I will find some other way to achieve this. — MrBott_a, Nov 07 '22 at 14:59

Is there a way to set a default function for getters and setters?

2 Answers2