kkeri / jsondl

A JSON declaration language.

JSONDL - a JSON declaration language

A domain specific language to document and validate JSON data in your JavaScript projects.

JSONDL is natural and javascripty. It is simple like this:

person.jsondl:

{
    "name": string,
    "age": number
}

app.js:

var jsondl = require('jsondl')

var personDecl = jsondl.load(require.resolve('./person.jsondl'))

if (personDecl.test({ name: 'Dan', age: '25' })) {
    console.log('Wow!')
}

What is JSONDL?

A programming language that lets you declare your JSON data.
JSONDL is a superset of JSON, meaning that any JSON file is its own declaration.

What is a JSON declaration?

A convenient way to document your JSON data: its structure, types and constraints.
It is also a precise specification that can be fed into a JSON validator.

JSON declarations are essentially data patterns. A JSON instance is valid if it matches a particular pattern.

Benefits

Readable - Declarations look similarly to validated data. You can actually develop a JSON declaration by editing a JSON file.

Intuitive - JSONDL is much like a type system for JSON. If you like Flow or Typescript, you will find it familiar.

Modular - Use ES6 imports and exports in your JSONDL files. Organize your declarations as any other code. No more intangible dependencies.

Extendable - Write your own extensions in JavaScript. The simplest kind of custom validator is just a function that accepts a single argument and returns true or false. Import your Javascript extensions directly into JSONDL.

Scalable - Publish your declarations and extensions as JavaScript packages and let others import or require them in their own projects.

JSONDL is work in progress. For more features, please look at functional tests in the test directory.

Installation

npm install jsondl

License

MIT