Level6Rogue.OrderEngine 1.0.4

OrderEngine

A flexible .NET library for ordering and organizing elements with support for relative positioning, groups, and hierarchical structures.

This project is a wip and I may change the API and features as I develop it.

Features

• Relative Ordering - Position elements before or after other elements
• Index-Based Ordering - Assign explicit priority indices to elements
• Grouping - Organize elements into hierarchical groups with different display types
• Cycle Detection - Automatically detects and reports circular dependencies
• Multiple Build Modes - Optimized for either single or multiple build scenarios

Installation

Install via NuGet:

dotnet add package Level6Rogue.OrderEngine

NuGet: https://www.nuget.org/packages/Level6Rogue.OrderEngine/

Quick Start

using OrderEngine;

// Create an order engine
IOrderEngine engine = OrderEngine.Create();

// Add elements
engine.Add("Item1");
engine.Add("Item2");
engine.Add("Item3");

// Build and get the ordered output
List<Output> result = engine.Build();

Ordering Rules

No Rule (Insertion Order)

Elements without ordering rules maintain their insertion order:

engine.Add("First");
engine.Add("Second");
engine.Add("Third");
// Result: First, Second, Third

Before

Position an element before another element:

engine.Add("A");
engine.Add("B");
engine.Add("C", new Before("B"));
// Result: A, C, B

After

Position an element after another element:

engine.Add("A");
engine.Add("B");
engine.Add("C", new After("A"));
// Result: A, C, B

ByIndex

Assign explicit priority indices for fine-grained control:

engine.Add("Item1", new ByIndex(10));
engine.Add("Item2", new ByIndex(5));
engine.Add("Item3", new ByIndex(15));
// Result: Item2, Item1, Item3 (sorted by index)

Negative indices are supported and sort before positive indices:

engine.Add("A");
engine.Add("B", new ByIndex(-100));
// Result: B, A

Groups

Implicit Groups (Path-Based)

Create groups using path separators (/):

engine.Add("Settings/Audio/Volume");
engine.Add("Settings/Audio/Mute");
engine.Add("Settings/Video/Resolution");

Output structure:

GroupStart: Settings
  GroupStart: Audio
    Volume
    Mute
  GroupEnd: Audio
  GroupStart: Video
    Resolution
  GroupEnd: Video
GroupEnd: Settings

Explicit Groups

Create empty groups or specify group types:

engine.AddGroup(new Group("MyGroup"));
engine.AddGroup(new Group("FoldableGroup", GroupType.Foldout));
engine.AddGroup(new Group("HorizontalGroup", GroupType.Horizontal));

Group Types

Build Modes

Choose the optimization strategy based on your usage pattern:

// For multiple Build() calls (with caching)
IOrderEngine engine = OrderEngineFactory.Create(BuildMode.MultipleBuild);

// For a single Build() call (minimal overhead)
IOrderEngine engine = OrderEngineFactory.Create(BuildMode.SingleBuild);

Output Types

The Build() method returns a list of Output objects:

foreach (var output in engine.Build())
{
    switch (output)
    {
        case GroupStart gs:
            Console.WriteLine($"Group Start: {gs.Name} ({gs.GroupType})");
            break;
        case GroupEnd ge:
            Console.WriteLine($"Group End: {ge.Name}");
            break;
        case OutputElement el:
            Console.WriteLine($"Element: {el.Name}");
            break;
    }
}

Updating Elements

Adding an element with the same name updates its ordering rule:

engine.Add("A");
engine.Add("B", new Before("A"));  // B is before A
engine.Add("B", new After("A"));   // B is now after A
// Result: A, B

Error Handling

Circular Dependencies

The engine detects and throws an exception for circular dependencies:

engine.Add("A", new Before("B"));
engine.Add("B", new Before("A"));
engine.Build(); // Throws exception: circular dependency detected

Invalid References

Referencing a non-existent element throws an exception:

engine.Add("A", new Before("NonExistent"));
engine.Build(); // Throws exception: target not found

API Reference

IOrderEngine Interface

public interface IOrderEngine
{
    void Add(Element element, OrderRule? orderRule = null);
    void AddGroup(Group group, OrderRule? orderRule = null);
    List<Output> Build();
}

Element

// Create explicitly
var element = new Element("MyElement");

// Or use implicit conversion from string
engine.Add("MyElement");

OrderRule Types

public abstract record OrderRule;
public record ByIndex(int Index) : OrderRule;
public record Before(string ElementName) : OrderRule;
public record After(string ElementName) : OrderRule;

License

MIT License