Refactor transport classes

[milan]

With the addition of Elastica/Transport/Guzzle (in #618 ) which is an alternative to Elastica/Transport/Http (and Https), there are two classes that implement the ElasticSearch JSON over HTTP protocol. Which should allow some level of refactoring, following the discussion in #618 how about something very roughly along the lines of this:

abstract class AbstractHttpTransport extends AbstractTransport {

public function exec (Request $request, array $params);
    $connection = $this->_getHttpConnection();
    $request = $this->_createRequest();
    $response = $this->_sendRequest($request);
}

protected function _getBaseUri() {
    $url = $connection->hasConfig('url') ? $connection->getConfig('url') : '';
    if (!empty($url)) {
        $baseUri = $url;
    } else {
        $baseUri = $this->_scheme . '://' . $connection->getHost() . ':' . $connection->getPort() . '/' . $connection->getPath();
    }
    return rtrim($baseUri, '/');
}

protected function _setContent() {
    return (is_array($data)) ? JSON::stringify($data, 'JSON_ELASTICSEARCH') : $data;
}

abstract protected function _getHttpConnection();
abstract protected function _createRequest();
abstract protected function _sendRequest();
}

Then have Http and Guzzle extend AbstractHttpTransport and implement the abstract methods, although I'm fine with just extracting the common code into a BaseHttp class?

[ruflin]

The way you approach it above looks good to me. We should probably call it AbstractHttp.

[milan]

Cool, i'll try and get this done this week.

[ruflin]

@milan I know, quite old. But are you still interested to push some changes here?

[killerwolf]

We should rely on PSR7/17/18

[ruflin]

I'm not too familiar with the new PSR standards but +1 on adopting them to standardise and make it easier for our users.