The Midway software design pattern

# 🧙‍♂️ The Midway Software Design Pattern: A New Software Design Pattern for Controlled Access

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## 🧠 What Is the Midway Method?

The Midway Method is a newly proposed software design pattern that introduces a clean, reusable way to restrict access to private behavior based on contextual trust. It's ideal for situations where you want to expose sensitive functionality — but only to a select group of objects.

Think of it as a gatekeeper inside your class. Instead of exposing a private method directly, you expose a midway method that checks whether the caller is trusted, and only then delegates to the private logic.

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## 🎯 Problem It Solves

Languages like Java don't support fine-grained access control beyond public/private/protected. What if you want:

- A method that's private, but accessible to specific objects?
- A way to validate callers before executing sensitive logic?
- A clean alternative to reflection, friend classes, or exposing too much?

The Midway Method solves this by creating a controlled access point inside your object.

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## 🧩 Pattern Structure

**Components**

- **Host**: The object that owns the private method and the midway method
- **Guest**: An object that may request access
- **Trusted List**: A list of guests allowed to invoke the private method
- **Midway Method**: A public method that checks trust and delegates

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## 🛠️ Java Example

java
public interface Guest {
void requestAccess(Host host);
}


java
public class Host {
private List trustedGuests = new ArrayList<>();

public void addGuest(Guest guest) {
    trustedGuests.add(guest);
}

private void secretMethod() {
    System.out.println("Secret method accessed!");
}

void grantAccess(Guest guest) {
    if (trustedGuests.contains(guest)) {
        secretMethod();
    } else {
        System.out.println("Access denied.");
    }
}

}


java
public class VIPGuest implements Guest {
@override
public void requestAccess(Host host) {
host.grantAccess(this);
}
}


java
public class Demo {
public static void main(String[] args) {
Host host = new Host();
Guest guest1 = new VIPGuest();
Guest guest2 = new VIPGuest();

    host.addGuest(guest1);

    guest1.requestAccess(host); // ✅ Secret method accessed!
    guest2.requestAccess(host); // ❌ Access denied.
}

}


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## 🧬 Why It's a Pattern

The Midway Method isn't just a coding trick — it's a repeatable architectural solution:

- ✅ Enforces contextual trust
- ✅ Keeps sensitive logic encapsulated
- ✅ Avoids exposing internal behavior
- ✅ Works across languages and platforms

It's especially useful in:
- 🔐 Secure plugin systems
- 🎮 Game mechanics (e.g., allies triggering buffs)
- 🧠 AI modules with internal trust networks

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## 🧙‍♂️ Origin Story

This pattern was first described by Moti Barski, who built a system where only objects in a list attribute could access a private method of the containing class. It wasn't documented anywhere — not in the Gang of Four, not in Fowler's catalog — making it a new contribution to software architecture.

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## 🧠 Final Thoughts

The Midway Method is a simple but powerful way to go beyond basic access control. It's not just composition — it's intentional trust-based delegation. If you've ever needed to expose behavior selectively, this pattern might be your new favorite tool.

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What do you think? Could this pattern evolve into something bigger — like dynamic trust levels or encrypted method calls? Drop your thoughts below 👇

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