ArmChair.php

<?php
require_once 'HTTP/Request2.php';
class ArmChair extends HTTP_Request2
{
    protected $server;
    
    public function __construct($server)
    {
        $this->server = $server;
        parent::__construct($server);
    }
    
    public function get($id = null)
    {
        if ($id === null) {
            $this->setUri($this->server . '/_all_docs')
        } else {
            $id = urlencode($id);
            $this->setUri($this->server . '/' . $id);
        }
        $this->setMethod(HTTP_Request2::METHOD_GET);
        $response = $this->send();
        return $this->parseResponse($response);
    }

    public function addDocument(array $data)
    {
        if (isset($data['_id'])) {
            $id = urlencode($data['_id']);
            unset($data['_id']);
            $this->setUri($this->server . '/' . $id);
            $this->setMethod(HTTP_Request2::METHOD_PUT);
        } else {
            $this->setUri($this->server);
            $this->setMethod(HTTP_Request2::METHOD_POST);
        }
        $this->setBody(json_encode($data));
        
        $response = $this->send();
        return $this->parseResponse($response);
    }

    public function deleteDocument($id)
    {
        $id = urlencode($id);
        $this->setUri($this->server . '/' . $id);
        $this->setMethod(HTTP_Request2::METHOD_DELETE);
        
        $response = $this->send();
        return $this->parseResponse($response);
    }

    public function updateDocument($id, $data)
    {
        $id = urlencode($id);
        $this->setUri($this->server . '/' . $id);
        $this->setMethod(HTTP_Request2::METHOD_POST);
        $this->setBody(json_encode($data));
        
        $response = $this->send();
        return $this->parseResponse($response);
    }
    
    protected function parseResponse(HTTP_Request2_Response $response)
    {
        return json_decode($response->getBody());
    }
}

// example
$armchair = new ArmChair('http://localhost:5984/guestbook');

$entry   = array('entry' => 'Great guestbook!', 'author' => 'Till');
$docData = $armchair->addDocument($entry);

$document = $armchair->getDocument($docData['id']);

$armchair->deleteDocument($docData['id']);