What is json-schema-ref-parser?
The json-schema-ref-parser npm package is a tool that can parse JSON Schema files and dereference $ref pointers. This allows you to combine multiple separate JSON Schema files into one resolved schema, validate JSON documents against schemas, and manipulate JSON Schemas programmatically.
What are json-schema-ref-parser's main functionalities?
Dereferencing $ref pointers
This feature allows you to take a JSON Schema that contains $ref pointers to other files or URLs and resolve them into a single JSON Schema object. This is useful for simplifying and flattening schemas that are spread across multiple files.
{"$ref": "http://example.com/my-schema.json"}
Bundle schemas into a single file
This feature lets you take a JSON Schema with $ref pointers to other files in your project and bundle them all into a single JSON Schema file. This can be useful for distribution or for loading a schema from a single file in a browser or other environments where multiple files are not convenient.
{"$ref": "definitions.json#/address"}
Parse JSON Schema to a JavaScript object
This feature allows you to parse a JSON Schema from a string, file, or URL into a JavaScript object. This can be useful for manipulating the schema programmatically or for using it in conjunction with other tools that operate on JavaScript objects.
{"type": "object", "properties": {"name": {"type": "string"}}}
Other packages similar to json-schema-ref-parser
ajv
Ajv is a JSON Schema validator that allows you to compile and validate JSON Schemas. It is similar to json-schema-ref-parser in that it can handle $ref pointers, but its primary focus is on validation rather than parsing and dereferencing.
json-schema
The json-schema package is another tool for validating JSON data against JSON Schemas. It is similar to json-schema-ref-parser in that it can parse and validate schemas, but it does not have the same focus on resolving $ref pointers.
tv4
Tiny Validator (tv4) is a small and fast JSON Schema validator. It is similar to json-schema-ref-parser in that it can validate JSON documents against schemas, but it does not provide the same level of support for dereferencing and bundling schemas.
JSON Schema $Ref Parser
Parse, Resolve, and Dereference JSON Schema $ref pointers
The Problem:
You've got a JSON Schema with $ref
pointers to other files and/or URLs. Maybe you know all the referenced files ahead of time. Maybe you don't. Maybe some are local files, and others are remote URLs. Maybe they are a mix of JSON and YAML format. Maybe some of the files contain cross-references to each other.
{
"definitions": {
"person": {
"$ref": "schemas/people/Bruce-Wayne.json"
},
"place": {
"$ref": "schemas/places.yaml#/definitions/Gotham-City"
},
"thing": {
"$ref": "http://wayne-enterprises.com/things/batmobile"
},
"color": {
"$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.
Features
- Works in Node, io.js, and all major web browsers on Windows, Mac, and Linux
- Supports JSON and YAML formats — even a mix of both!
- Resolves all
$ref
pointers, including pointers to external files and URLs - Configurable caching of external files
- Supports circular references, nested references, back-references, and cross-references between files
- Can dereference your schema, combining everything into a single JavaScript object that's easy to work with
- Different
$ref
pointers to the same value resolve to the same object instance, thus maintaining reference equality - You can choose to dereference only internal
$refs
, external $refs
, or both
Installation
Install using npm or bower, or just download ref-parser.js
or ref-parser.min.js
.
Node
npm install json-schema-ref-parser
Bower
bower install json-schema-ref-parser
Sample Usage
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/bigstickcarpet/json-schema-ref-parser.git
-
Install dependencies
npm install
-
Run the build script
npm run build
-
Run the unit tests
npm run mocha
(test in Node)
npm run karma
(test in web browsers)
npm test
(test in Node and browsers, and report code coverage)
License
JSON Schema $Ref Parser is 100% free and open-source, under the MIT license. Use it however you want.