Rule Engine System

A robust rule engine that evaluates complex conditions using an Abstract Syntax Tree (AST) representation. This project allows users to create, manage, and combine rules dynamically, enabling advanced decision-making capabilities.

Table of Contents

• Features
• System Requirements
• Installation
• Configuration
• Running the Application
• Testing
• Usage

Features

• Dynamic rule creation and management.
• Support for combining rules with logical operators (AND, OR).
• Evaluation of rules against JSON input data.
• Use of an Abstract Syntax Tree (AST) for complex condition evaluation.

System Requirements

• Java 21 (OpenJDK)
• Maven 3.8 or higher
• MySQL or another relational database for storage

Installation

1. Clone the Repository:

   git clone https://github.com/dipakja/RuleEngineAST.git
   cd RuleEngineAST
   

2.Install Dependencies: Ensure you have Maven installed. Then, run the following command in the project directory:

mvn install

Configuration

1.Database Credentials: Open the src/main/resources/application.properties file and configure your database credentials:

spring.datasource.url=jdbc:mysql://localhost:3306/your_database_name
spring.datasource.username=your_database_username
spring.datasource.password=your_database_password

2.Database Schema: Create the necessary tables using the following SQL queries: rules Table:

CREATE TABLE rules (
    id BIGINT AUTO_INCREMENT PRIMARY KEY,
    rule_string TEXT NOT NULL,  
    root_node_id BIGINT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

ast_nodes Table:

CREATE TABLE ast_nodes (
    id BIGINT AUTO_INCREMENT PRIMARY KEY,
    type ENUM('operator', 'operand') NOT NULL,  
    operator_value ENUM('AND', 'OR') NULL, 
    operand_value TEXT NULL,  
    parent_id BIGINT,  
    left_child_id BIGINT NULL,  
    right_child_id BIGINT NULL, 
    rule_id BIGINT NOT NULL, 
    FOREIGN KEY (rule_id) REFERENCES rules(id) ON DELETE CASCADE,
    FOREIGN KEY (left_child_id) REFERENCES ast_nodes(id) ON DELETE SET NULL,
    FOREIGN KEY (right_child_id) REFERENCES ast_nodes(id) ON DELETE SET NULL
);

combined_rules Table:

CREATE TABLE combined_rules (
    id BIGINT AUTO_INCREMENT PRIMARY KEY,
    rule_1_id BIGINT NOT NULL,  
    rule_2_id BIGINT NOT NULL,  
    operator_value ENUM('AND', 'OR') NOT NULL,  
    combined_rule_id BIGINT, 
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (rule_1_id) REFERENCES rules(id) ON DELETE CASCADE,
    FOREIGN KEY (rule_2_id) REFERENCES rules(id) ON DELETE CASCADE,
    FOREIGN KEY (combined_rule_id) REFERENCES rules(id) ON DELETE CASCADE
);

Running the Application

To run the application, use the following command in the project directory:

mvn spring-boot:run

Once the application is running, you can access it at:

http://localhost:8080

Testing

Test Cases: 1.System Setup: Verify that the system starts successfully and connects to the database. 2.Rule Evaluation: Test the evaluation of various rules against input data to ensure correct results. 3.Rule Combination: Verify that combined rules evaluate correctly based on the logical operator. 4.Data Integrity: Check that the rules and nodes are correctly stored and retrievable from the database.

Usage

After accessing the application in your browser, you will see a user interface that allows you to create, evaluate, and manage rules. You can input JSON data for evaluation and visualize how rules are combined.