Google has vast number of API’s. Among them Google Contacts API is one of them. Recently i have to work with this API including Codeigniter. But there is very limited number of post which describes everything very clearly. Therefore as i worked with this one, i am sharing my knowledge here.

Tools that i used:

• Framework: Codeigniter
• Library: Zend Library with Codeigniter
• A test account in Google for testing the API functionality.

What will be done:

• Import list of contacts from an Existing Google Account and add them to a another google account(test account)
• Update Contact information through API
• Delete Contact from Google Account using API
• Add new contact to google account

A. Import Contacts from a Google Account

First of all, add the Zend Library folder in codeigniter libraries folder. Create a library file in codeigniter/library folder called Zend.php. Put the following contents into the file:

<?php if (!defined('BASEPATH')) {exit('No direct script access allowed');}

class Zend
{
    /**
     * Include the Zend library once
     * we load the zend Library class
     *
     * @param   none
     * @return  none
     */
    function __construct(){
        ini_set('include_path',
        ini_get('include_path') . PATH_SEPARATOR . APPPATH . 'libraries');

    }

    /**
     * Load Zend Library
     *
     * @param   string $class
     * @return  object $class
     */
    function load($class){
        require_once (string) $class . EXT;
    }
}
/* End of Zend.php */

Then we need a Existing Google Email account User Name and Password. We will pass the parameter through our controller methods. Inside the method we will load the library Zend.php. Then using this library we will load the Zend Gdata Library for importing the Contacts using Google API’s.
Have a look on the following code:

	/**
	 * Import Contacts using Zend Library
	 *
	 * @access	private
	 * @param	string	$accountUserName
	 * @param	string 	$accountPassword
	 * @return	none
	 */
	private function _importContacts($accountUserName, $accountPassword){
		$this->load->library('zend');
		$this->zend->load('Zend/Loader');

		Zend_Loader::loadClass('Zend_Gdata');
	    Zend_Loader::loadClass('Zend_Gdata_ClientLogin');
	    Zend_Loader::loadClass('Zend_Http_Client');
	    Zend_Loader::loadClass('Zend_Gdata_Query');
	    Zend_Loader::loadClass('Zend_Gdata_Feed');

	    try{
	    	//perform account login and set protocol version
			$client = Zend_Gdata_ClientLogin::getHttpClient($accountUserName, $accountPassword, 'cp');
			$gData  = new Zend_Gdata( $client );
			$gData->setMajorProtocolVersion(3);

			//perform query and get result from feed
			$query  = new Zend_Gdata_Query('http://www.google.com/m8/feeds/contacts/default/full');
			$query->startIndex = 0;
			$query->maxResults = 25;
		    $query->setParam('orderby', 'lastmodified');
		    $query->setParam('sortorder', 'descending');
			$feed   = $gData->getFeed($query); 

			$this->data['AccountTitle']  = $feed->title;
			$this->data['currentNumber'] = 25;
			$this->data['TotalResults']  = $feed->totalResults;
			$this->data['contactList']   = $this->_processFeedResult($feed);

		}catch(Exception $e){
			die('Error: ' . $e->getMessage());
		}
	}

Comming soon…