examples

Examples - Go Rules Engine

This folder contains usage examples of the Go rules engine.

📚 Available Examples

1. basic/main.go

Basic Example - Simple age verification with a single rule.

go run examples/basic/main.go

Demonstrates:

• ✅ Engine creation
• ✅ Simple rule with condition
• ✅ greater_than operator
• ✅ Tests with different values

2. json/main.go

JSON Loading - Load rules and facts from JSON.

go run examples/json/main.go

Demonstrates:

• ✅ Unmarshaling JSON rules
• ✅ Unmarshaling JSON facts
• ✅ Adding rules to engine
• ✅ Adding facts to almanac
• ✅ VIP and regular rules

3. custom-operator/main.go

Custom Operators - Creating custom operators.

go run examples/custom-operator/main.go

Demonstrates:

• ✅ Operator interface
• ✅ CustomOperator implementation
• ✅ starts_with, ends_with, between operators
• ✅ RegisterOperator to register operators

4. advanced/main.go

Advanced Features - Callbacks, handlers and dynamic facts.

go run examples/advanced/main.go

Demonstrates:

• ✅ Named callbacks with RegisterCallback
• ✅ Global handler OnSuccess
• ✅ Specific handler per event type On()
• ✅ Dynamic facts (discount calculation)
• ✅ Multiple simultaneous handlers

5. full-demo.go

Complete Demonstration - All features in a single example.

go run examples/full-demo.go

Demonstrates:

• ✅ Simple and complex rules
• ✅ Nested conditions (all/any)
• ✅ Callbacks and handlers
• ✅ JSON loading
• ✅ Dynamic facts
• ✅ JSONPath
• ✅ Event history

🚀 Execution

From the project root:

# Basic example
go run examples/basic/main.go

# JSON
go run examples/json/main.go

# Custom operators
go run examples/custom-operator/main.go

# Advanced
go run examples/advanced/main.go

# Full demo
go run examples/full-demo.go

📖 Complete Documentation

See the main README for complete API documentation.

💡 Quick Start

To create your own application:

1. Import:

   import gorulesengine "github.com/deadelus/go-rules-engine/src"
   

2. Engine:

   engine := gorulesengine.NewEngine()
   

3. Rule:

   rule := &gorulesengine.Rule{
       Name:     "my-rule",
       Priority: 100,
       Conditions: gorulesengine.ConditionSet{
           All: []gorulesengine.ConditionNode{
               {
                   Condition: &gorulesengine.Condition{
                       Fact:     "age",
                       Operator: "greater_than",
                       Value:    18,
                   },
               },
           },
       },
       Event: gorulesengine.Event{
           Type: "adult",
       },
   }
   engine.AddRule(rule)
   

4. Almanac:

   almanac := gorulesengine.NewAlmanac([]*gorulesengine.Fact{})
   almanac.AddFact("age", 25)
   

5. Run:

   results, err := engine.Run(almanac)
   if err != nil {
       log.Fatal(err)
   }
   
   for _, result := range results {
       if result.Result {
           fmt.Printf("✅ %s\n", result.Event.Type)
       }
   }
   

📝 Example Structure

examples/
├── README.md           # This file
├── full-demo.go        # Complete demo
├── basic/              # Basic example
│   └── main.go
├── json/               # JSON loading
│   └── main.go
├── custom-operator/    # Custom operators
│   └── main.go
└── advanced/           # Advanced features
    └── main.go

Check each example for specific use cases!