Com.RickSeven.FormulaEngine.Core 1.0.4

Com.RickSeven.FormulaEngine

A powerful and flexible formula evaluation engine using Roslyn Scripting with dynamic runtime context. Ideal for scenarios where business logic needs to be defined at runtime through C# expressions or formulas.

🚀 Features

• Evaluate C# expressions dynamically at runtime
• Support for nested objects and complex data structures
• JSON context support for easy integration
• Rich set of operations:
  • Numeric operations (arithmetic, Math functions)
  • String manipulation and formatting
  • DateTime operations
  • Logical operations and conditionals
  • Collection handling with indexing
• Culture-specific formatting support
• Comprehensive error handling
• No external dependencies other than Roslyn and BCL

🎞 Installation

Install via NuGet:

dotnet add package Com.RickSeven.FormulaEngine.Core --version 1.0.0

Or using the NuGet Package Manager:

PM> Install-Package Com.RickSeven.FormulaEngine.Core

🧠 Usage Examples

Basic Operations

var context = new Dictionary<string, object>
{
    { "revenue", 10000 },
    { "cost", 7000 },
    { "margin", 0.3 },
    { "desc", "Result is: " }
};

string formula = "desc + ((revenue - cost) * margin).ToString()";

var engine = new FormulaEngine();
var result = engine.Evaluate(formula, context);

// Output: "Result is: 900"
Console.WriteLine(result);

Math Functions

var context = new Dictionary<string, object>
{
    { "baseValue", 2.0 },
    { "exponent", 3.0 }
};

string formula = "Math.Pow(baseValue, exponent)";

var engine = new FormulaEngine();
var result = engine.Evaluate(formula, context);

// Output: 8.0
Console.WriteLine(result);

Culture-Specific Formatting

var jsonContext = @"{
    ""revenue"": 1000.50,
    ""cost"": 750.25,
    ""taxRate"": 0.2,
    ""description"": ""Profit calculation: ""
}";

var formula = @"description + ((revenue - cost) * (1 - taxRate)).ToString(""C2"", new System.Globalization.CultureInfo(""id-ID""))";

var engine = new FormulaEngine();
var result = engine.Evaluate(formula, jsonContext);

// Output: Profit calculation: Rp200,20
Console.WriteLine(result);

Nested Objects and Collections

var jsonContext = @"{
    ""person"": {
        ""firstName"": ""John"",
        ""lastName"": ""Doe"",
        ""phones"": [
            {""type"": ""home"", ""number"": ""555-1234""},
            {""type"": ""work"", ""number"": ""555-5678""}
        ]
    },
    ""company"": {
        ""name"": ""Acme Corp"",
        ""address"": {
            ""city"": ""Silicon Valley"",
            ""coordinate"": {
                ""latitude"": 37.37,
                ""longitude"": -122.04
            }
        }
    }
}";

var engine = new FormulaEngine();

// Access nested properties
var result1 = engine.Evaluate("person.firstName + \" \" + person.lastName", jsonContext);
// Output: "John Doe"

// Access array elements
var result2 = engine.Evaluate("person.phones[0].number", jsonContext);
// Output: "555-1234"

// Complex nested property access with string interpolation
var result3 = engine.Evaluate(@"$""{person.firstName} works in {company.address.city}""", jsonContext);
// Output: "John works in Silicon Valley"

// Conditional array access
var result4 = engine.Evaluate("person.phones[person.phones[0].type == \"home\" ? 0 : 1].number", jsonContext);
// Output: "555-1234"

DateTime Operations

var context = new Dictionary<string, object>
{
    { "date", new DateTime(2023, 1, 1) }
};

var formula = "date.AddDays(10).Day";
var engine = new FormulaEngine();
var result = engine.Evaluate(formula, context);

// Output: 11
Console.WriteLine(result);

Error Handling

try
{
    var context = new Dictionary<string, object> { { "x", 5 } };
    var engine = new FormulaEngine();
    var result = engine.Evaluate("x + y", context); // 'y' is not defined
}
catch (FormulaEvaluationException ex)
{
    // Handle evaluation error
    Console.WriteLine(ex.Message);
}

📝 Notes

• The engine supports full C# expression syntax
• Nested objects can be accessed using dot notation
• Array elements can be accessed using index notation
• JSON context is automatically parsed and made available to formulas
• Culture-specific formatting is supported through standard .NET formatting
• Error handling is provided through FormulaEvaluationException
• Variable names cannot use C# reserved keywords (e.g., 'base', 'class', 'static', etc.)

📧 Support

For bug reports or support inquiries, please contact:

• Email: maseric7@gmail.com