LogicBuilder.Workflow.Activities.Rules 2.0.6

LogicBuilder.Workflow.Activities.Rules

A powerful, forward-chaining rules engine for .NET that enables dynamic business rule evaluation and execution without recompilation. This library provides a flexible framework for defining, validating, and executing business rules using CodeDOM expressions.

Overview

LogicBuilder.Workflow.Activities.Rules is a .NET rules engine that allows you to:

• Define business rules declaratively using CodeDOM expressions
• Validate rules against target types at design-time or runtime
• Execute rules with forward-chaining and re-evaluation support
• Serialize/deserialize rule sets for storage and versioning
• Support complex conditions and actions including method calls, property access, and object creation

Core Components

RuleEngine

The RuleEngine class is the execution engine that processes validated rule sets against target objects. It handles:

• Rule preprocessing and analysis
• Forward-chaining execution with configurable chaining behavior
• Rule priority management
• Re-evaluation of rules when object state changes

RuleSet

The RuleSet class represents a collection of rules that can be executed together. Features include:

• Named rule collections with optional descriptions
• Configurable chaining behavior (Full, Sequential, None)
• Rule validation against target types
• Serialization support for persistence
• Cloning capabilities for rule set management

Properties:

• Name - Unique identifier for the rule set
• Description - Optional documentation
• Rules - Collection of Rule objects
• ChainingBehavior - Controls how rules trigger re-evaluation

Chaining Behaviors:

• Full - Rules can trigger re-evaluation of all other rules
• Sequential - Rules execute in priority order without re-evaluation
• None - No forward chaining

RuleValidation

The RuleValidation class validates rule expressions against target types and provides type resolution services. It:

• Validates rule conditions and actions at design-time or runtime
• Resolves types, methods, properties, and fields
• Manages type conversions and implicit/explicit operators
• Supports extension methods (C# 3.0+)
• Provides detailed validation errors with line information

Key Capabilities:

• Type Resolution: Resolves types from assemblies including generic types
• Method Resolution: Finds best-match methods considering overloads, optional parameters, and params arrays
• Property/Field Resolution: Validates member access including indexers
• Conversion Validation: Checks implicit and explicit type conversions
• Access Validation: Enforces visibility rules (public, internal, private)

Supported Expression Types

The library supports a rich set of CodeDOM expressions:

• Binary operations: Comparison, arithmetic, logical operators
• Property/field access: Including nested properties
• Method invocation: Instance and static methods
• Array indexers: Multi-dimensional array access
• Object creation: Constructor calls with parameters
• Type casting: Explicit type conversions
• Generic types: Full support for generic type arguments
• Collection initializers: Array and list initialization

Advanced Features

Forward Chaining

Rules can trigger re-evaluation of other rules when they modify object state, enabling complex rule dependencies and cascading logic.

Update Actions

Use RuleUpdateAction to explicitly mark properties as updated, forcing re-evaluation of dependent rules:

rule.ThenActions.Add(new RuleUpdateAction("this/PropertyName"));

Target Frameworks

• .NET Standard 2.0

Use Cases

This library is ideal for:

• Business rule engines requiring dynamic rule modification
• Policy-based systems with versioned rule sets
• Complex validation scenarios with cascading rules
• Decision automation systems
• Workflow rule evaluation
• Configurable business logic without code deployment