@readme/json-schema-ref-parser

What is @readme/json-schema-ref-parser?

@readme/json-schema-ref-parser is a powerful library for parsing, resolving, and dereferencing JSON Schema $ref pointers. It allows you to work with complex JSON schemas that contain references to other schemas, making it easier to manage and validate large and interconnected JSON data structures.

What are @readme/json-schema-ref-parser's main functionalities?

Parsing JSON Schema

This feature allows you to parse a JSON schema from a file or URL. The parsed schema is returned as a JavaScript object.

const $RefParser = require('@readme/json-schema-ref-parser');

async function parseSchema() {
  const schema = await $RefParser.parse('path/to/your/schema.json');
  console.log(schema);
}

parseSchema();

Resolving JSON Schema References

This feature resolves all $ref pointers in the JSON schema, replacing them with the actual referenced values. This is useful for working with schemas that reference other schemas.

const $RefParser = require('@readme/json-schema-ref-parser');

async function resolveSchema() {
  const schema = await $RefParser.resolve('path/to/your/schema.json');
  console.log(schema);
}

resolveSchema();

Dereferencing JSON Schema

This feature dereferences all $ref pointers in the JSON schema, replacing them with the actual referenced values. The result is a fully dereferenced schema with no $ref pointers.

const $RefParser = require('@readme/json-schema-ref-parser');

async function dereferenceSchema() {
  const schema = await $RefParser.dereference('path/to/your/schema.json');
  console.log(schema);
}

 dereferenceSchema();

Bundling JSON Schema

This feature bundles all referenced schemas into a single schema. This is useful for creating a standalone schema that contains all the necessary definitions.

const $RefParser = require('@readme/json-schema-ref-parser');

async function bundleSchema() {
  const schema = await $RefParser.bundle('path/to/your/schema.json');
  console.log(schema);
}

bundleSchema();

Other packages similar to @readme/json-schema-ref-parser

json-schema-ref-parser

json-schema-ref-parser is a popular library for parsing, resolving, and dereferencing JSON Schema $ref pointers. It offers similar functionalities to @readme/json-schema-ref-parser, including parsing, resolving, and dereferencing JSON schemas. The main difference is that @readme/json-schema-ref-parser is a fork of json-schema-ref-parser with additional features and improvements.

json-schema-deref-sync

json-schema-deref-sync is a synchronous library for dereferencing JSON Schema $ref pointers. Unlike @readme/json-schema-ref-parser, which is asynchronous, json-schema-deref-sync performs dereferencing synchronously, which can be useful in certain scenarios where asynchronous operations are not desired.

json-schema-resolver

json-schema-resolver is a library for resolving JSON Schema $ref pointers. It focuses on resolving references and does not provide parsing or dereferencing functionalities. It is a simpler alternative to @readme/json-schema-ref-parser for users who only need reference resolution.

README

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 v10, v12, & v14, 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 {
  const 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 @readme/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("@readme/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 "@readme/json-schema-ref-parser";

Differences from @apidevtools/json-schema-ref-parser

• Forces YAML to conform to JSON-compatible types. https://github.com/APIDevTools/json-schema-ref-parser/pull/247
• Improved support for OpenAPI 3.1 definitions where $ref pointers may live alongside a description property. https://github.com/readmeio/json-schema-ref-parser/pull/2
• Exposes a new $refs.circularRefs property containing an array of any circular $ref pointers that may exist within the schema definition.

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

License

JSON Schema $Ref Parser is 100% free and open-source, under the MIT license. Use it however you want.

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