# aria2.js

JavaScript library for [aria2, "The next generation download utility."](https://aria2.github.io/)

- [Introduction](#introduction)
- [Getting started](#getting-started)
- [Usage](#usage)
  - [open](#open)
  - [close](#close)
  - [call](#call)
  - [multicall](#multicall)
  - [batch](#batch)
  - [listNotifications](#listnotifications)
  - [listMethods](#listmethods)
  - [events](#events)

## Introduction

aria2.js controls aria2 via its [JSON-RPC interface](https://aria2.github.io/manual/en/html/aria2c.html#rpc-interface) and features

- Node.js and browsers support
- multiple transports
  - [HTTP](https://aria2.github.io/manual/en/html/aria2c.html#rpc-interface)
  - [WebSocket](https://aria2.github.io/manual/en/html/aria2c.html#json-rpc-over-websocket)
- promise API
- no 3rd party dependency

See [aria2 methods](https://aria2.github.io/manual/en/html/aria2c.html#methods) and [aria2 notifications](https://aria2.github.io/manual/en/html/aria2c.html#notifications).

[↑](#aria2js)

## Getting started

Start aria2 with rpc, example:

`aria2c --enable-rpc --rpc-listen-all=true --rpc-allow-origin-all`

Install aria2.js

```sh
npm install aria2
```

[↑](#aria2js)

## Usage

```js
import Aria2 from "aria2";

const aria2 = new Aria2(options);
````

In the browser you can also use `node_modules/aria2/bundle.js` directly in `<script>` and `window.Aria2`.

Aria2 extends [EventTarget](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget).

Default options match aria2c defaults and are

```javascript
{
  host: 'localhost',
  port: 6800,
  secure: false,
  secret: '',
  path: '/jsonrpc',
}
```

`secret` is optional and refers to [--rpc-secret](https://aria2.github.io/manual/en/html/aria2c.html#cmdoption--rpc-secret). If you define it, it will be added to every call for you.

If the WebSocket is open (via the [open method](#open)) aria2.js will use the WebSocket transport, otherwise the HTTP transport.

The `"aria2."` prefix can be omitted from both methods and notifications.

[↑](#aria2js)

### open

`aria2.open()` opens the WebSocket connection. All subsequent requests will use the WebSocket transport instead of HTTP.

```javascript
await aria2.open();
console.log("open");
```

[↑](#aria2js)

### close

`aria2.close()` closes the WebSocket connection. All subsequent requests will use the HTTP transport instead of WebSocket.

```javascript
await aria2.close();
console.log("closed");
```

[↑](#aria2js)

### call

`aria2.call()` calls a method. Parameters are provided as arguments.

Example using [`addUri`](https://aria2.github.io/manual/en/html/aria2c.html#aria2.addUri) method to download from a magnet link.

```javascript
const magnet =
  "magnet:?xt=urn:btih:88594AAACBDE40EF3E2510C47374EC0AA396C08E&dn=bbb_sunflower_1080p_30fps_normal.mp4&tr=udp%3a%2f%2ftracker.openbittorrent.com%3a80%2fannounce&tr=udp%3a%2f%2ftracker.publicbt.com%3a80%2fannounce&ws=http%3a%2f%2fdistribution.bbb3d.renderfarming.net%2fvideo%2fmp4%2fbbb_sunflower_1080p_30fps_normal.mp4";
const guid = await aria2.call("addUri", [magnet], { dir: "/tmp" });
```

[↑](#aria2js)

### multicall

`aria2.multicall()` is a helper for [system.multicall](https://aria2.github.io/manual/en/html/aria2c.html#system.multicall). It returns an array of results or throw if any of the call failed.

```javascript
const multicall = [
  [methodA, param1, param2],
  [methodB, param1, param2],
];

const results = await aria2.multicall(multicall);
```

### batch

`aria2.batch()` is a helper for [batch](https://www.jsonrpc.org/specification#batch). It behaves the same as [multicall](#multicall) except it returns an array of promises which gives more flexibility in handling errors.

```javascript
const batch = [
  [methodA, param1, param2],
  [methodB, param1, param2],
];

const promises = await aria2.batch(batch);
```

[↑](#aria2js)

### listNotifications

`aria2.listNotifications()` is a helper for [system.listNotifications](https://aria2.github.io/manual/en/html/aria2c.html#system.listNotifications). The difference with `aria2.call('listNotifications')` is that it removes the `"aria2."` prefix from the results.

```javascript
const notifications = await aria2.listNotifications();
/*
[
  'onDownloadStart',
  'onDownloadPause',
  'onDownloadStop',
  'onDownloadComplete',
  'onDownloadError',
  'onBtDownloadComplete'
]
*/

// notifications logger example
notifications.forEach((notification) => {
  aria2.addEventListener(notification, ({detail}) => {
    console.log("aria2", notification, detail);
  }});
});
```

[↑](#aria2js)

### listMethods

`aria2.listMethods()` is a helper for [system.listMethods](https://aria2.github.io/manual/en/html/aria2c.html#system.listMethods). The difference with `aria2.call('listMethods')` is that it removes the `"aria2."` prefix for the results.

```javascript
const methods = await aria2.listMethods();
/*
[ 'addUri',
  [...]
  'system.listNotifications' ]

*/
```

[↑](#aria2js)

### events

```javascript
// emitted when the WebSocket is open.
aria2.addEventListener("open", () => {
  console.log("aria2", "OPEN");
});

// emitted when the WebSocket is closed.
aria2.addEventListener("close", () => {
  console.log("aria2", "CLOSE");
});

// emitted when error occur.
aria2.addEventListener("error", ({ error }) => {
  console.error("aria2", "error", error);
});

// emitted for every data sent.
aria2.addEventListener("input", ({ data }) => {
  console.log("aria2", "IN");
  console.dir(data);
});

// emitted for every data received.
aria2.addEventListener("output", ({ data }) => {
  console.log("aria2", "OUT");
  console.dir(data);
});

// emitted for every notification received.
aria2.addEventListener("notification", ({ method, params }) => {
  console.log("aria2", "notification", { method, params });
});
```

Additionally, every [aria2 notifications](https://aria2.github.io/manual/en/html/aria2c.html#notifications) is also emitted as an event. Only available when using WebSocket, see [open](#open).

```javascript
aria2.addEventListener("onDownloadStart", ({params: [guid]}) => {
  console.log("aria2 onDownloadStart", guid);
});
```

[↑](#aria2js)