jsonrpc-websocket-client/README.md

# jsonrpc-websocket-client [![Build Status](https://travis-ci.org/jsonrpc-websocket-client.png?branch=master)](https://travis-ci.org/jsonrpc-websocket-client)

> JSON-RPC 2 over WebSocket

## Install

Installation of the [npm package](https://npmjs.org/package/jsonrpc-websocket-client):

```
> npm install --save jsonrpc-websocket-client
```

This library requires promises support, for Node versions prior to 0.12 [see
this page](https://github.com/JsCommunity/promise-toolbox#usage) to
enable them.

## Usage

```javascript
import Client from "jsonrpc-websocket-client";

async function main() {
  const client = new Client("ws://example.org");

  console.log(client.status);
  // → closed

  await client.open();

  console.log(client.status);
  // → open

  console.log(await client.call("method", [1, 2, 3]));

  await client.close();
}

// Run the main function and prints any errors.
main().catch(error => {
  console.error(error);
  process.exit(1);
});
```

### Creation

```js
const client = new Client(opts);
```

`opts` is either a string (the URL of the server) or an object with
the following properties:

- `url`: URL of the JSON-RPC server
- `protocols` (_optional_): the WebSocket sub-protocols to use

### Connection management

**Status**

```js
console.log(client.status);
```

Possible values:

- `open`
- `connecting`
- `closed`

**Connection**

```js
await client.open();
```

**Disconnection**

```js
await client.close();
```

This method can also be used to abort the connection while connecting.

### Events

**Connection**

```js
client.on("open", () => {
  console.log("client is now open");
});
```

**Disconnection**

```js
client.on("closed", () => {
  console.log("client is now closed");
});
```

**Notification**

```js
client.on("notification", notification => {
  console.log("notification received", notification);
});
```

## Recipes

### Always stay connected

> Reconnect on disconnection:

```js
client.on("closed", () => {
  client.open();
});
```

> Use back off to keep retrying to connect:

```js
import { createBackoff } from "jsonrpc-websocket-client";

client.open(createBackoff());
```

## Development

```
# Install dependencies
> yarn

# Run the tests
> yarn test

# Continuously compile
> yarn dev

# Continuously run the tests
> yarn dev-test

# Build for production (automatically called by npm install)
> yarn build
```

## Contributions

Contributions are _very_ welcomed, either on the documentation or on
the code.

You may:

- report any [issue](https://github.com/JsCommunity/jsonrpc-websocket-client/issues)
  you've encountered;
- fork and create a pull request.

## License

ISC © [Julien Fontanet](https://julien.isonoe.net)