@networkteam/eel

Embedded expression language, a parser and compiler for a safe subset of JavaScript for dynamic evaluation in JavaScript.

Features

• Safe evaluation of JS expressions:
  • !a || (b && c)
  • number == 42
  • foo.bar.baz
  • foo["bar"].baz
  • myFn(1, 2, 3)
  • myObj.method(arg1).prop
• Compiles expressions from strings to plain JS functions
• Safe to use with user generated expressions (e.g. as a filter language)
• Use in the browser or with Node.js

Installation

yarn add @networkteam/eel

or

npm install --save @networkteam/eel

Usage

import { compile } from '@networkteam/eel`

const expr = compile('myVar');

const result = expr({myVar: 'a', 'otherVar': b});

// result === 'a'

Ideally, the expression should be pre-compiled. The generated function can be used with different context values to evaluate the result.

Reference

compile(expression)

expression: string

Compiles the given expression and returns a function that receives the current context for evaluation. The context must be an object that contains all defined variables as properties.

Licence

MIT