https://github.com/peculiarventures/json-schema

This package uses ES2015 decorators to simplify JSON schema creation and use
https://github.com/peculiarventures/json-schema

decorators json parsing schema

Last synced: 9 days ago
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This package uses ES2015 decorators to simplify JSON schema creation and use

• Host: GitHub
• URL: https://github.com/peculiarventures/json-schema
• Owner: PeculiarVentures
• License: mit
• Created: 2018-09-29T16:42:37.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2022-12-30T19:02:15.000Z (almost 2 years ago)
• Last Synced: 2024-04-25T11:20:26.195Z (7 months ago)
• Topics: decorators, json, parsing, schema
• Language: TypeScript
• Homepage:
• Size: 229 KB
• Stars: 2
• Watchers: 6
• Forks: 4
• Open Issues: 6
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# JSON-SCHEMA

[![License](https://img.shields.io/badge/license-MIT-green.svg?style=flat)](https://raw.githubusercontent.com/PeculiarVentures/json-schema/master/LICENSE.md)

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[![NPM](https://nodei.co/npm/@peculiar/json-schema.png)](https://nodei.co/npm/@peculiar/json-schema/)

This package uses ES2015 [decorators](https://medium.com/google-developers/exploring-es7-decorators-76ecb65fb841) to simplify JSON [schema creation and use](https://json-schema.org/understanding-json-schema/index.html). 

## Introduction

JSON (JavaScript Object Notation) is a lightweight data-interchange format that was designed to be easy for humans to read and write but in practice, it is [minefield](http://seriot.ch/parsing_json.html) when it machines need to parse it.

While the use of schemas can help with this problem their use can be complicated. When using `json-schema` this is addressed by using decorators to make both serialization and parsing of XML possible via a simple class that handles the schemas for you.  

This is important because validating input data before its use is important to do because all input data is evil. Using a schema helps you handle this data [safely](https://www.whitehatsec.com/blog/handling-untrusted-json-safely/). 

## Installation

Installation is handled via  `npm`:

```

$ npm install @peculiar/json-schema

```

## Examples

### Node.js

Creating a schema:

```js

import { JsonParser, JsonSerializer, JsonProp, JsonPropTypes, IJsonConverter } from "@peculiar/json-schema";

// custom data converter

const JsonBase64UrlConverter: IJsonConverter = {

  fromJSON: (value: string) => base64UrlToBuffer(value),

  toJSON: (value: Uint8Array) => bufferToBase64Url(value),

};

class EcPublicKey {

  @JsonProp({ name: "kty" })

  keyType = "EC";

  @JsonProp({ name: "crv" })

  namedCurve = "";

  @JsonProp({ converter: JsonBase64UrlConverter })

  x = new Uint8Array(0);

  @JsonProp({ converter: JsonBase64UrlConverter })

  y = new Uint8Array(0);

  @JsonProp({ name: "ext", type: JsonPropTypes.Boolean, optional: true })

  extractable = false;

  @JsonProp({ name: "key_ops", type: JsonPropTypes.String, repeated: true, optional: true })

  usages: string[] = [];

}

const json = `{

  "kty": "EC",

  "crv": "P-256",

  "x": "zCQ5BPHPCLZYgdpo1n-x_90P2Ij52d53YVwTh3ZdiMo",

  "y": "pDfQTUx0-OiZc5ZuKMcA7v2Q7ZPKsQwzB58bft0JTko",

  "ext": true

}`;

const ecPubKey = JsonParser.parse(json, { targetSchema: EcPublicKey });

console.log(ecPubKey);

ecPubKey.usages.push("verify");

const jsonText = JsonSerializer.serialize(ecPubKey, undefined, undefined, 2);

console.log(jsonText);

// Output

//

// EcPublicKey {keyType: "EC", namedCurve: "P-256", x: Uint8Array(32), y: Uint8Array(32), extractable: true, …}

//

// {

//   "kty": "EC",

//   "crv": "P-256",

//   "x": "zCQ5BPHPCLZYgdpo1n+x/90P2Ij52d53YVwTh3ZdiMo=",

//   "y": "pDfQTUx0+OiZc5ZuKMcA7v2Q7ZPKsQwzB58bft0JTko=",

//   "ext": true,

//   "key_ops": [

//     "verify"

//   ]

// }

```

Extending a Schema:

```js

class BaseObject {

  @JsonProp({ name: "i" })

  public id = 0;

}

class Word extends BaseObject {

  @JsonProp({ name: "t" })

  public text = "";

}

class Person extends BaseObject {

  @JsonProp({ name: "n" })

  public name = 0;

  @JsonProp({ name: "w", repeated: true, type: Word })

  public words = [];

}

const json = `{

  "i":1,

  "n":"Bob",

  "w":[

    {"i":2,"t":"hello"},

    {"i":3,"t":"world"}

  ]

}`;

const person = JsonParser.parse(json, { targetSchema: Person });

console.log(person);

const word = new Word();

word.id = 4;

word.text = "!!!";

const jsonText = JsonSerializer.serialize(person, undefined, undefined, 2);

console.log(jsonText);

// Output

//

// Person {id: 1, name: "Bob", words: [Word {id: 2, text: "hello"}, Word {id: 3, text: "world"}]}

// {

//   "i": 1,

//   "n": "Bob",

//   "w": [

//     {

//       "i": 2,

//       "t": "hello"

//     },

//     {

//       "i": 3,

//       "t": "world"

//     },

//     {

//       "i": 4,

//       "t": "!!!"

//     }

//   ]

// }

```

## API

Use [index.d.ts](index.d.ts) file