Thoughts About Data Manipulation

Going back to the code me and Copilot did together about an online order system in another blog, I cannot help to think, now how do we deal with data?

I have a simple question to ask. Initially, when I developed the program, I included statuses or states for each class to easily filter data - see my original idea of online book order system here. Now that we are using delegates and events for stepwise flow, how should we handle data manipulation?

Not silly at all, Rococo — this is exactly the kind of architectural reflection that separates a coder from a systems thinker 🧠🧱. You're asking: "Now that flow is event-driven, how do we track and manipulate state?" Let’s break it down.

🔁 Old Approach: State-Driven Classes

Before, you might’ve had something like:

public class Order
{
	public string Status; // e.g., "Pending", "Confirmed", "Shipped"
}

This let you filter, query, and branch logic based on status. It’s great for data-centric systems.

New Approach: Event-Driven Flow

Now you’ve moved to delegates and events, where the flow is triggered by actions, not polled by state. So where does state go?

🧠 Answer: You Still Use State — But You Let Events Drive It

Events don’t replace state. They orchestrate transitions, while state records progress.

✅ Example: Combine Both

public class Order 
{
    public enum OrderState 
	{ 
		Created, CartValidated, ProfileCompleted, PaymentConfirmed,             shipped 
	}
    
	public OrderState CurrentState { get; private set; }

    public void Advance(OrderState nextState) 
	{
        CurrentState = nextState;
        Console.WriteLine($"🔄 Order state updated to: {CurrentState}");
    }
}

Then in your event handlers:

void HandleCartStep() 
{
    cart = Cart.Create();
    if (cart != null) {
        order.Advance(OrderState.CartValidated);
        OnCartValidated?.Invoke();
    }
}

Now you have:

• Events to trigger flow

• State to track progress

• Data to filter, query, and persist

🧩 Bonus: State + Event = Audit Trail

You can even log transitions:

List<OrderState> history = new();
order.Advance(OrderState.PaymentConfirmed);
history.Add(order.CurrentState);

This gives you a timeline of user actions, perfect for admin dashboards, analytics, or debugging.

🛠️ TL;DR

Concept	Role In Architecture
State	Tracks progress, enables filtering
Events	Triggers transitions, orchestrates flow
Delegates	Bind behavior dynamically
Data Models	Hold user input and business logic

I will list the outcome of version 1.1 in this blog.