Chain Pattern for .NET

Chain is a powerful execution pattern designed for composing sequential operations in .NET. It combines aspects of the Chain of Responsibility pattern with workflow and pipeline concepts to provide flexible, ordered execution of operations.

Overview

Chain provides a clean architecture for building processing pipelines. A IChain<T> manager class orchestrates the execution of multiple ILink<T> implementations in sequence. The ExecuteAll() method iterates through each link's Execute() method, allowing the manager class to define the execution sequence.

Key Features

• Sequential Execution: Links execute in a defined order
• Flexible Control Flow: Links can stop execution or jump to the closing action
• Closing Action Support: Optional post-processing method that runs after all links
• Ready-to-Use Implementation: The EmptyChain<T> class provides out-of-the-box functionality
• Dependency Injection Support: Integrate seamlessly with .NET Core IoC containers
• Updated for .NET 8: Fully compatible with the latest .NET framework

Execution Control

Manager class also can have a method called ClosingAction. This action will be run after execution of all links.

Links have two control mechanisms:

• StopExecution(): Halts the chain without running ClosingAction
• StopPropagation(): Halts the chain but still executes ClosingAction (if defined)

Usage Examples

There is a ready to use chain called EmptyChain in this assembly. New chains can be implemented either directly from IChain or by inheriting from EmptyChain.

Basic Usage with EmptyChain

Create a simple chain by composing links together:

var message = new Message { Name = "M1" }; var c = new EmptyChain<Message>(); c.AddLink<L1>(); c.AddLink<L2>(); c.ExecuteAll(message);

Custom Chain Class

Inherit from EmptyChain for custom chain definitions:

public class L1L2Chain : EmptyChain<Message> { public L1L2Chain() { AddLink<L1>(); AddLink<L2>(); } } var c = new L1L2Chain(); c.ExecuteAll(message);

Dependency Injection Integration