Using ZF for uploading PDF to Google Docs API 3.0

 
class Ext_Gdata_Uploader
{
	const SESSION_URI = "https://docs.google.com/feeds/upload/create-session/default/private/full";
	const VERSION = "3.0";
 
	/**
	 * The default chunk size in bytes.
	 * 
	 * @var Integer 
	 */
	protected $_chunkSize = 524288;
 
	/**
	 * The Http Client
	 * 
	 * @var Zend_Gdata_ 
	 */
	protected $_client = null;
 
	/**
	 * The current uri for upload the next chunk. 
	 * 
	 * @var string 
	 */
	protected $_uploadUri = null;
 
	/**
	 * The path to file for upload. 
	 * 
	 * @var string 
	 */
	protected $_filelocation = null;
 
	/**
	 * The file name in the list of entries. 
	 * 
	 * @var string 
	 */
	protected $_title = null;
 
	/**
	 * The mime type of file to upload.
	 * 
	 * @var string 
	 */
	protected $_mime = "application/pdf";
 
	/**
	 * The mime type of file to upload.
	 * 
	 * @var string 
	 */
	protected $_sessiontoken = null;
 
	/**
	 * The handle of file to upload.
	 * 
	 * @var filehanle 
	 */
	protected $_filehandle = null;
 
	/**
	 * The size of file to upload.
	 * 
	 * @var integer
	 */
	protected $_fileSize = null;
 
	/**
	 * The number of current chunk of file to upload.
	 * 
	 * @var integer
	 */
	protected $_currentChunk = 1;
 
	/**
	 * The count chunks of file to upload.
	 * 
	 * @var integer
	 */
	protected $_countChunk = null;
 
 
       public function __construct($client, $filelocation, $title = "Untitled", 
           $mime = null, $chunkSize = null)
    {
        $this->_client = $client;
    	$this->_filelocation = $filelocation;
        if($chunkSize)
    		$this->_chunkSize = $chunkSize;
    	if($title)
    		$this->_title = $title;
    	if($mime)
    		$this->_mime = $mime;
    	$this->_sessiontoken = $this->_client->getClientLoginToken();		
    }
 
	private function initFile()
    {
    	$this->_filehandle = fopen($this->_filelocation, "r");
    	if($this->_filehandle)
    	{
    		$this->_fileSize = filesize($this->_filelocation);
    		rewind($this->_filehandle); 
    		$this->_countChunk  = ceil($this->_fileSize/$this->_chunkSize);    		
    		return true;
    	}
    	return false;
    }
 
    private function createSession()
    {
    	if($this->_client)
    	{
			$this->_client->setUri(self::SESSION_URI);
    		  $this->_client->setHeaders("GData-Version",self::VERSION);
			$this->_client->setHeaders("Content-Length","0");
			$this->_client->setHeaders("Slug",$this->_title);
			$this->_client->setHeaders("X-Upload-Content-Type",$this->_mime);
			$this->_client->setHeaders("X-Upload-Content-Length",
                                                   $this->_fileSize);
			$this->_client->setHeaders("Authorization",
                             "GoogleLogin auth=".$this->_sessiontoken);
			$response = $this->_client->request('POST');
			if(200 == $response->getStatus())
			{	
				$this->_uploadUri = $response->getHeader("Location");
				return true;
			}			  		
    	}
    	return false;
    }
 
    private function uploadNextChunk($data, $startByte, $endByte, $sizeChunk)
	{
		$this->_client->setUri($this->_uploadUri);
		$this->_client->setHeaders("Content-Length",$sizeChunk);
		$this->_client->setHeaders("Content-Range","bytes ".$startByte.
                                           "-".$endByte."/".$this->_fileSize);
		$this->_client->setRawData($data);
		return $this->_client->request('PUT');
	}
 
    public function upload()
    {
 
    	$this->initFile();
    	$this->createSession();
 
    	while($this->_currentChunk <= $this->_countChunk)
    	{
    		if($this->_currentChunk == $this->_countChunk)
    		{
    			$startByte = (($this->_countChunk <= 1) ? 0 : 
                            ($this->_chunkSize*($this->_countChunk-1)));
    			$sizeChunk = $this->_fileSize % $this->_chunkSize;
    			$sizeChunk = ($sizeChunk ? $sizeChunk : $this->_chunkSize);
    			$data = fread($this->_filehandle, $sizeChunk);
    			$response = $this->uploadNextChunk($data, $startByte, 
                                           $this->_fileSize-1, $sizeChunk);
    			if(201 == $response->getStatus())
    				return new Zend_Gdata_Entry($response->getbody());
    			return null;	
    		}else 
    		{
    			$startByte = (($this->_currentChunk == 1) ? 0 : 
                         (($this->_currentChunk-1)*$this->_chunkSize)); 
    			$sizeChunk = $this->_chunkSize;
    			$data = fread($this->_filehandle, $sizeChunk);    
    			$response = $this->uploadNextChunk($data, $startByte, 
                         ($startByte+$this->_chunkSize)-1, $this->_chunkSize);
    			if(308 != $response->getStatus())
    				return false;
 
    		}
    		$this->_currentChunk++;
    	}
 
    }
 
	public function __destruct()
	{
		if($this->_filehandle)
			fclose($this->_filehandle);
	}
 
 
};

     $googleUsername ="your_username";
     $googlePassword = "your_password";
     $pathToPdf="/path/to/pdf";
     $pdfDocumentName = "name.pdf";
     $docService = Zend_Gdata_Docs::AUTH_SERVICE_NAME;
 
     $docClient = Zend_Gdata_ClientLogin::getHttpClient($googleUsername, $googlePassword, $docService);
     $uploader = new Ext_Gdata_Uploader($docClient, $pathToPdf, $pdfDocumentName);
     $entry = $uploader->Upload();
     $link = $entry->getAlternateLink()->getHref();