JSON Schema KeyRef

About

This is an extension to the standard JSON Schema. It allows for validating the references to remote values, actually have the value that is being referenced.

See Example for a sample use case.

Installation

Install from npm

npm install --save json-schema-keyref

Usage

const fs = require("fs");
const jsonSchemaKeyref = require("json-schema-keyref");

const document = JSON.parse(fs.readSync("document.json"));
const schema = JSON.parse(fs.readSync("schema.json"));

// Validate document against standard JSON schema using tv4 or another library

const result = jsonSchemaKeyref.validate(document, schema);

console.log(result); //=> {"errors": [], "isValid": true}

Example

Below is a User and Transaction database. Where users have an id and name. And transactions are from one user id, to another user id, with an amount.

Using key reference validator, transaction 2 would be flagged because user 3 does not exist in the data.

Data:

{
  "users": [
    {
      "id": 1,
      "name": "user 1"
    },
    {
      "id": 2,
      "name": "user 2"
    }
  ],
  "transactions": [
    {
      "from": 1,
      "to": 2,
      "amount": 1.0
    },
    {
      "from": 3,
      "to": 1,
      "amount": 99.99
    }
  ]
}

Schema:

{
  "key": {
    "to": "$.users[*].id",
    "from": "$.users[*].id"
  },
  "keyref": {
    "to": "$.transactions[*].to",
    "from": "$.transactions[*].from"
  },

  "title": "Employee and Transaction Database",
  "type": "object",
  "properties": {
    "users": {
      "type": "object",
      "properties": {
        "id": {
          "type": "integer"
        },
        "name": {
          "type": "string"
        }
      },
      "required": ["id", "name"]
    },
    "transactions": {
      "type": "object",
      "properties": {
        "to": {
          "type": "integer"
        },
        "from": {
          "type": "integer"
        },
        "amount": {
          "type": "number"
        }
      }
    }
  },
  "required": ["users", "transactions"]
}