SlackMessageSender.php

<?php

namespace Acme\Component\Slack\Message;

use Acme\Component\Slack\Message\MessageInterface;
use Acme\Component\Slack\Message\SenderInterface;
use Guzzle\Http\ClientInterface;
use Guzzle\Http\Message\Response;

/**
 * Slack message sender.
 */
class Sender implements SenderInterface
{
    /**
     * @var string
     */
    private $url;

    /**
     * @var ClientInterface
     */
    private $client;


    /**
     * @param string $url
     * @param ClientInterface $client
     */
    public function __construct($url, ClientInterface $client)
    {
        $this->url = $url;
        $this->client = $client;
    }

    /**
     * @param string $channel
     * @param MessageInterface $message
     * @return Response
     */
    public function send($channel, MessageInterface $message)
    {
        $request = $this->client->post($this->url, array(), http_build_query(array(
            'payload' => json_encode(array(
                'channel' => $channel,
                'text' => $message->getText(),
                'username' => $message->getUserName(),
                'icon_emoji' => $message->getIconEmoji(),
                'link_names' => $message->getLinkNames(),
            ))
        )));

        $request->setHeader('Content-Type', 'application/x-www-form-urlencoded');
        $response = $request->send();

        if (!$response->isSuccessful()) {
            throw new \UnexpectedValueException('Request unsuccessful(status).');
        }
        
        return $response;
    }
}

3系のGuzzleを使ってSlackにメッセージ送るときのサンプル。

エンコードされたBodyをPOSTで送るのに

$request->setHeader('Content-Type', 'application/x-www-form-urlencoded');

が必要

Sample class how to send payload to slack with Guzzle version 3.x.

Need this line to post encoded body.

$request->setHeader('Content-Type', 'application/x-www-form-urlencoded');