OCL.jsOCL for JavaScript and TypeScript

Parse and evaluate OCL constraints in JavaScript and TypeScript — in the browser or Node.js.

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API Reference

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OCL Parsing

Parse OCL expressions from strings using a Jison-generated parser built for JavaScript.

Constraint Evaluation

Object Querying

Use OCL query expressions (e.g. self->any(i | i < 1)) to query and filter object collections.

TypeScript-first

Written in TypeScript with full type definitions. Dual CJS + ESM output via tsup.

Flexible Type System

Label-based Filtering

Tag OCL rules with labels and evaluate only a specific subset during a run.

What is OCL?

The Object Constraint Language (OCL) is a language for describing rules that apply to MOF-conform modelling languages like UML. It is a text-based language that provides constraint and object query expressions that cannot be expressed by a meta-modelling language.

Since implementations exist in Java (e.g. Eclipse Modelling Framework) but not in JavaScript, OCL.js fills that gap. This library does not claim to be fully compliant with the OMG OCL specification and may have slight differences.

Quick Start

bash

npm install @stekoe/ocl.js

typescript

import { OclEngine } from '@stekoe/ocl.js';

const oclEngine = OclEngine.create();

oclEngine.addOclExpression(`
  context Person inv: self.parents->forAll(p | p <> self)
`);

const result = oclEngine.evaluate(new Person());
console.log(result.getResult()); // true