Rule Engine

A React application that allows users to create, combine, and evaluate rules. The rules are represented as Abstract Syntax Trees (AST) and can be visualized using a tree structure.

Features

• Create Rule: Allows users to input a rule in the format field operator value (e.g., age > 30). The rule is validated and converted into an AST.

• Combine Rules: Combines multiple rules using logical operators (AND, OR) to create a more complex rule represented as a single AST.

• Evaluate Rule: Evaluates the combined AST against provided JSON data to determine if the data satisfies the rule.

• Visualize AST: Displays the AST of individual rules and the combined AST as a tree structure using react-d3-tree.

• NOTE : when we click on create rule -> a tree is generated and shown at frontend but it is in left-most corner , you need to drag it to the center to clearly see it , same happens when we click on combine rules.

Prerequisites

• Node.js (v14 or later)
• npm (v6 or later)

Getting Started

Clone the Repository

git clone https://github.com/amantripathigithub/Application-1-Rule-Engine-with-AST.git

cd Application-1-Rule-Engine-with-AST.git



Backend Setup
Navigate to the backend directory:

---cd backend



Install dependencies:

---npm install



Start the backend server:

---node index.js

The backend server will run on http://localhost:5000.





Frontend Setup

Navigate to the frontend directory:

---cd frontend

Install dependencies:

---npm install


Start the frontend development server:

---npm start


The frontend server will run on http://localhost:3000.





Usage
Open your web browser and navigate to http://localhost:3000.

Create Rule: Enter a rule in the input field and click "Create Rule". The rule should be in the format field operator value (e.g., age > 30).

Combine Rules: After creating at least two rules, click "Combine Rules" to combine them into a single AST.

Evaluate Rule: Enter JSON data in the textarea (e.g., {"age": 32, "department": "Sales"}) and click "Evaluate Rule". The result (true/false) will be displayed based on whether the data satisfies the combined rule.

Visualize AST: The AST for individual rules and the combined AST will be displayed as tree structures.

Example : 
Create the following rules:

age > 30
department = Sales
age < 25
department = Marketing
Combine the rules.

Enter the following JSON data for evaluation:
{
  "age": 32,
  "department": "Sales"
}
The evaluation result should be true if the combined AST is satisfied by the provided data.

screenshots