JSON Schema $Ref Parser
Parse, Resolve, and Dereference JSON Schema $ref pointers
The Problem:
You've got a JSON Schema with $ref
pointers to other files and/or URLs. Maybe you know all the referenced files ahead of time. Maybe you don't. Maybe some are local files, and others are remote URLs. Maybe they are a mix of JSON and YAML format. Maybe some of the files contain cross-references to each other.
{
"definitions": {
"person": {
// references an external file
"$ref": "schemas/people/Bruce-Wayne.json"
},
"place": {
// references a sub-schema in an external file
"$ref": "schemas/places.yaml#/definitions/Gotham-City"
},
"thing": {
// references a URL
"$ref": "http://wayne-enterprises.com/things/batmobile"
},
"color": {
// references a value in an external file via an internal reference
"$ref": "#/definitions/thing/properties/colors/black-as-the-night"
}
}
}
The Solution:
JSON Schema $Ref Parser is a full JSON Reference and JSON Pointer implementation that crawls even the most complex JSON Schemas and gives you simple, straightforward JavaScript objects.
- Use JSON or YAML schemas — or even a mix of both!
- Supports
$ref
pointers to external files and URLs, as well as custom sources such as databases - Can bundle multiple files into a single schema that only has internal
$ref
pointers - Can dereference your schema, producing a plain-old JavaScript object that's easy to work with
- Supports circular references, nested references, back-references, and cross-references between files
- Maintains object reference equality —
$ref
pointers to the same value always resolve to the same object instance - Tested in Node and all major web browsers on Windows, Mac, and Linux
Example
$RefParser.dereference(mySchema, (err, schema) => {
if (err) {
console.error(err);
}
else {
// `schema` is just a normal JavaScript object that contains your entire JSON Schema,
// including referenced files, combined into a single object
console.log(schema.definitions.person.properties.firstName);
}
}
Or use async
/await
syntax instead. The following example is the same as above:
try {
let schema = await $RefParser.dereference(mySchema);
console.log(schema.definitions.person.properties.firstName);
}
catch(err) {
console.error(err);
}
For more detailed examples, please see the API Documentation
Installation
Install using npm:
npm install json-schema-ref-parser
Usage
When using Json-Schema-Ref-Parser in Node.js apps, you'll probably want to use CommonJS syntax:
const $RefParser = require("json-schema-ref-parser");
When using a transpiler such as Babel or TypeScript, or a bundler such as Webpack or Rollup, you can use ECMAScript modules syntax instead:
import $RefParser from "json-schema-ref-parser";
Browser support
Json-Schema-Ref-Parser supports recent versions of every major web browser. Older browsers may require Babel and/or polyfills.
To use Json-Schema-Ref-Parser in a browser, you'll need to use a bundling tool such as Webpack, Rollup, Parcel, or Browserify. Some bundlers may require a bit of configuration, such as setting browser: true
in rollup-plugin-resolve.
API Documentation
Full API documentation is available right here
Contributing
I welcome any contributions, enhancements, and bug-fixes. File an issue on GitHub and submit a pull request.
Building/Testing
To build/test the project locally on your computer:
-
Clone this repo
git clone https://github.com/APIDevTools/json-schema-ref-parser.git
-
Install dependencies
npm install
-
Run the build script
npm run build
-
Run the tests
npm test
License
JSON Schema $Ref Parser is 100% free and open-source, under the MIT license. Use it however you want.
Big Thanks To
Thanks to these awesome companies for their support of Open Source developers