Rule-Engine-Using-AST

Hosted link: https://app1-rule-engine-with-ast.onrender.com/

Overview

This application is a rule engine that determines user eligibility based on attributes such as age, department, salary, and experience. It uses an Abstract Syntax Tree (AST) to represent and manage conditional rules, allowing for dynamic rule creation, combination, and evaluation.

Features

Create Rules: Define rules using a string format that gets converted into an AST.
Combine Rules: Combine multiple rules into a single AST for more complex evaluations.
Evaluate Rules: Check if the given data meets the criteria defined by the AST.
Tree Visualization: Define or Combine Rule would should show Tree Representation.

Tech Stack

Backend: Node.js, Express.js
Database: MongoDB

Getting Started

Prerequisites

Node.js and npm installed
MongoDB installed and running

Installation

Clone the Repository

git clone "https://github.com/D-D-Roshan/Rule-Engine-Using-AST.git"
cd rule-engine

Install Backend Dependencies
```
npm install
```
Start MongoDB

Ensure that MongoDB is running on your local machine:
```
mongod
```
Start the Backend Server
```
nodemon server.js
```

Edit the Mongodb URI

  mongodb+srv://db_name:<db_password>@ast.cscvg.mongodb.net/?retryWrites=true&w=majority&appName=AST
  db_name with your db name
  db_password with your db password

API Endpoints

Create a Rule

Endpoint: /api/create_rule
Method: POST

Body:

{
  "ruleString": "((age > 30 AND department = 'Sales') OR (age < 25 AND department = 'Marketing')) AND (salary > 50000 OR experience > 5)",
  "ruleName": "Rule 1"
}

use appropriate spaces in Rules for correct results.

Rule should be in follow format: variable operator value

Response:

{
  "_id": "605c72ef1f4e3a001f4d2e9a",
  "rule_name": "Rule1",
  "rule_ast": { ... }
}

Combine Rules

Endpoint: /api/rules/combine_rules
Method: POST

Body:

{
  "ruleIds": ["605c72ef1f4e3a001f4d2e9a", "605c730f1f4e3a001f4d2e9b"]
  "operators: op
}

Response:

{
  "type": "operator",
  "value": operator,
  "left": { ... },
  "right": { ... }
}

Evaluate a Rule

Endpoint: /api/rules/evaluate_rule
Method: POST

Body:

{
  "rule": { ... },
  "data": {
    "age": 35,
    "department": "Sales",
    "salary": 60000,
    "experience": 3
  }
}

Response:
```
{
  "result": true
}
```

Running Tests

You can add and run tests to ensure everything is working correctly.

created bt: Roshan