Dmn-engine NPM

Business-Rules Engine

Condition Symbols

Column Value: $$ example DateDiff($$,@now)
variable symbol: $example: $caseId this is needed since we allow multi words operations like starts with
Is null value or empty: Null or Empty
Any Value: -
All types:
- null or empty
- not null
- true or false

Introduction

Is a Business Rules Engine supporting DMN Decision Tables. Allowing developers to integrate Rules into JavaScript or Node.js applications.

This solution utilizes deterministic rules vs Rete based solutions that are non-deterministic.

This package is designed specifically for Node.js and TypeScript

As an example of Decisition Table Example

Anatomy

Usage

Definition

Decision table can be defined as a JSON or CSV file

Invoke

To invoke the above example

    const Rules=requires('./business-rules.json')'
    const dt= Rules.load('client-category);
    let result=dt.run({type:'Private',  deposit: 500 , netWorth: 500});

    console.log(result.category);

Testing

    const tester=Rules.loadTest('./client-category-tests.json');
    let results=tester.run();
    console.log(results.summary);

tests

UI for Testing and expeirmenting

Rule Syntax

Conditions

Expression Language

Simple Conditions shortcuts

Literal values with or without quotes, so "high" and high are acceptable
coditional operators and functions without referencing the variable like >500
Empty Condition or - indicates all values are true
For numeric variables:
- 500
- between 500 and 700
For Date variables, functions like:
- > 30 days , > 50 minutes , < 10 years etc.
- before '2018/01/01' or after '2018/03/01'
- between '2018/01/01' and '2019/12/31'

Complex Conditions

And , Or and Not operators, brackets () can also be used
complex operations and functions can reference the variable using @ symbol

Output

Output expressions can use the full expression language and reference any input or ouput variable.

Expression Engine

    const exp=new Expression(`2+3*4`);
    const result= expr.evaluate();
    console.log(result);

Expressions are compiled into AST

    const exp=new Expression(`2+3*4`);
    const compiled= expr.compile();

    // or reloaed

    const expr=Expression.load(compiled);
    const result= expr.evaluate();

    console.log(result);