Jexl Extended Grammar

This package includes an extended grammar for the Jexl expression parser and evaluator by TomFrost.

📚 Complete Documentation | 🎮 Try the Playground

Features

• 🚀 80+ Built-in Functions - String manipulation, math, arrays, objects, dates, and more
• 🎨 Monaco Editor Support - Syntax highlighting, IntelliSense, and hover documentation
• 📝 TypeScript Support - Full type definitions included
• 🔧 Modular - Use the entire library or import individual functions
• 🎮 Interactive Playground - Try expressions online at jexl-playground.konnektr.io

Installation

npm install jexl-extended

Quick Start

import jexl from 'jexl-extended';

const data = [
  {name: "John", age: 32}, 
  {name: "Jane", age: 34}, 
  {name: "Bob", age: 33}
];

const result = jexl.evalSync('data|filter("value.age > 32")|map("value.name")|join(", ")', {data});
// "Jane, Bob"

Monaco Editor Integration

Get a rich IDE experience for JEXL expressions:

import * as monaco from 'monaco-editor';
import { Monaco } from 'jexl-extended';

// Register JEXL language support
Monaco.registerJexlLanguage(monaco);

// Create editor with JEXL support
const editor = Monaco.createJexlEditor(monaco, document.getElementById('editor'), {
  value: 'users|filter("value.active")|map("value.name")|sort',
  theme: 'vs-dark'
});

📖 See full Monaco integration guide

It is also possible to use the extended grammar in the original Jexl library by importing parts of the grammar you need and adding it to the Jexl instance.

import jexl from 'jexl';
import { arrayMap } from 'jexl-extended/extended-grammar';

jexl.addTransform('map', arrayMap);
const result = jexl.evalSync('[{name:"tek",age:32}, {name:"bar",age:34}, {name:"baz",age:33}, {name:"foo",age:35}]|map("value.age")');
// [32, 34, 33, 35]

Other Language Implementations

This extended grammar is also available in other programming languages:

• C#: JexlNet - A C# implementation of JEXL with extended grammar support
• Python: pyjexl-extended - Python implementation with extended functions and transforms

Related Projects

• Jexl - The original JavaScript implementation of JEXL that this library extends
• jexl-rs - A Rust-based JEXL parser and evaluator
• PyJEXL - Mozilla's Python-based JEXL parser and evaluator