# Protocol Base for ReactPHP

Use this library to build protocols. It doesn't do any single protocol to any greater
extent, but it provides callbacks and scaffolding for you to build and stream most
protocol data.

## About the protocols

This library is intended to be generic, so only protocols that have no external
dependencies will be included. 

## Using

### Protocols

```php
// Basic line-oriented protocol, think shell or SMTP
$proto = new LineProtocol($stream, [
    'lineSeparator' => "\n",
    'fieldSeparator' => " ",
    'fieldQuote' => '"',
]);

// encode your frames and send it however you desire
$data = $proto->packFrame([ "mv", "foo.txt", "bar.txt" ]);
// → mv foo.txt bar.txt\n

// Or use JSON if you so desire
$proto = new JsonProtocol($stream, [
    'frameSeparator' => "\0",
]);
$data = $proto->packFrame([ 'foo' => 'bar' ]);
// → {"foo":"bar"}\0
```

Unpacking works as expected:

```php
$proto = new LineProtocol($stream, [
    'lineSeparator' => "\n",
    'fieldSeparator' => " ",
    'fieldQuote' => '"',
]);

// encode your frames and send it however you desire
$cmdline = $proto->unpackFrame("mv foo.txt bar.txt\n" ]);
// → [ "mv", "foo.txt", "bar.txt" ]
```

### Protocols with ProtocolStream

ProtocolStream combines a ProtocolInterface and a DuplexStreamInterface into
one package. It will emit an `message` event when a new frame has been
decoded, an `error` event if something goes wrong, and an `overflow` event
if the buffer overflows a configured max size.

```php
$stream = new ProtocolStream($proto, $someduplexstream);
$stream->on("message", function (array $message) {
    // ...
});
$stream->send([ 'data' => 'here' ]);
```