Method To Set Nested Property Value

Question

I'm writing a plugin for a piece of software that requires all code to be in a single class (or nested classes)...

What I'm wanting to do is create a method that can handle changes to the nested properties of my _data object and give me a central place to do things like setting a dirty flag so I know to save it later.

Below is some code illustrating my file's structure and at the bottom are two pseudo-methods that hopefully can give you an idea of what I'm trying to accomplish.

public class SomePlugin
{
    private DataObject _data;
    private bool _dataIsDirty = false;

    private class DataObject
    {
        public GeneralSettings Settings { get; set; }
    }

    private class GeneralSettings
    {
        public string SettingOne { get; set; }
        public string SettingTwo { get; set; }
    }

    protected override void Init()
    {
        _data = new DataObject
        {
            Settings = new GeneralSettings
            {
                SettingOne = "Example value one.",
                SettingTwo = "Example value two."
            }
        }
    }

    // These are pseudo-methods illustrating what I'm trying to do.
    private void SetData<t>(T ref instanceProperty, T newValue)
    {
        if (newValue == null) throw new ArgumentNullException("newValue");
        if (instanceProperty == newValue) return;

        instanceProperty = newValue;
        _dataIsDirty = true;
    }

    private void SomeOtherMethod()
    {
        SetData(_data.Settings.SettingOne, "Updated value one.");
    }

}

Sorry, I should have mentioned that I have no way of installing or using any third party libraries or packages aside from what's already provided. It's a plugin for a game that runs on Unity. — user1960364, Aug 18 '17 at 11:53
Would https://learn.microsoft.com/en-us/dotnet/framework/winforms/how-to-implement-the-inotifypropertychanged-interface help? — mjwills, Aug 18 '17 at 11:54
Looks interesting but I have no idea if it would work or how to try implementing it into my structure. You keep suggesting these event-based solutions... Is this because it's not possible to do an implementation similar to the pseudo-methods I wrote? — user1960364, Aug 18 '17 at 12:03
If you don't want to use `INotifyPropertyChanged` consider my answer below. — mjwills, Aug 18 '17 at 13:03
It's not so much that I don't want to use it, I don't know how. C# isn't my forte so I'm learning as I go, I'm used to working with type agnostic languages like PHP and JavaScript... If it's cleaner than what you've posted below, I'd much prefer it because those data objects are converted to JSON (which is handled by the plugin manager) for storage and adding `IsDirty` properties adds useless clutter to the JSON. — user1960364, Aug 18 '17 at 13:08
You can put `[JsonIgnore]` on `IsDirty` so that it doesn't 'pollute' the JSON. — mjwills, Aug 18 '17 at 13:10
Oh, cool, I wasn't aware of the JsonIgnore attribute. But also, I'd want it to flag ANY changes to the object, not just that single property. So that'd be a lot of repetition if done to each property. :/ — user1960364, Aug 18 '17 at 13:12
`So that'd be a lot of repetition if done to each.` Yes it would. That is why I suggested https://github.com/Fody/PropertyChanged initially. :P — mjwills, Aug 18 '17 at 13:13

score 0 · Answer 1 · answered Aug 18 '17 at 12:31

Consider an approach like:

public class SomePlugin
{
    private DataObject _data;
    private bool _dataIsDirty = false;

    public bool IsDirty => _dataIsDirty || (_data?.IsDirty ?? false);

    private class DataObject
    {
        private bool _dataIsDirty = false;

        public bool IsDirty => _dataIsDirty || (Settings?.IsDirty ?? false);
        public GeneralSettings Settings { get; set; }
    }

    private class GeneralSettings
    {
        public bool IsDirty { get; set; }

        private string _settingOne;

        public string SettingOne
        {
            get { return _settingOne; }
            set
            {
                if (value != _settingOne)
                {
                    IsDirty = true;
                    _settingOne = value;
                }
            }
        }

        public string SettingTwo { get; set; } // Won't mark as dirty
    }
}

Note in particular that SettingOne has logic in its setter to determine whether to set IsDirty or not.

Method To Set Nested Property Value

1 Answers1