dromrules

A generic CSV-driven rule evaluator for Java objects.
Define simple condition‑action rules in a CSV file, and apply them to any Java Collection<T>. Uses reflection to read/write bean properties, with a builder-style API.

Features

• Generic: works with any POJO.
• CSV-based: author rules in a human-readable .csv.
• Multiple conditions per rule, including ==, >, <, >=, <=, and wildcard *.
• Multiple actions per rule, setting one or more properties.
• Dynamic values: use $fieldName to copy another property’s value.
• Builder API: easy setup with EvaluatorBuilder.

Getting Started

Prerequisites

• Java 8+ (tested on Java 11 and 21)
• Maven 3.6+

Installation

Clone the repo and build:

git clone https://github.com/drompincen/dromrules.git
cd dromrules
mvn clean install

Usage
Prepare your CSV (src/test/resources/rules.csv):

csv
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condition,condition,condition,action,action
color,weight,type,tag,category
red,>400,suv,truck,heavy
yellow,=500,*,\$color,light
Build an evaluator and process your objects:

java
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import com.example.evaluator.Evaluator;
import com.example.evaluator.EvaluatorBuilder;

import java.io.File;
import java.util.List;

// ...
File rulesFile = new File("src/test/resources/rules.csv");
Evaluator<Car> evaluator = EvaluatorBuilder.builder(Car.class).build();

List<Car> cars = List.of(
    new Car("red", 500, "suv"),
    new Car("yellow", 500, null)
);
evaluator.process(cars, rulesFile);

cars.forEach(car -> {
    System.out.println(car.getColor()
        + " → tag=" + car.getTag()
        + ", category=" + car.getCategory());
});
Run tests:

bash
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mvn test
CSV Format
Header Row 0: the words condition and action repeated to indicate columns.

Header Row 1: comma‑separated bean property names (e.g. color,weight,type,tag,category).

Subsequent Rows: one rule per line:

Columns 0–N: condition values (match order of condition property names).

Columns N+1–end: action values (match order of action property names).

Use operators in conditions:

=value or value → equals

>value, <value, >=value, <=value → comparisons

* → wildcard (matches anything, including null)

In actions, prefix with $ to copy another field's current value (e.g. \$color).

Contributing
Fork the repo

Create your feature branch (git checkout -b feature/foo)

Commit your changes (git commit -am 'Add foo')

Push to the branch (git push origin feature/foo)

Open a Pull Request

License
This project is licensed under the MIT License. See LICENSE for details.