bkite_php_library.php

<?php

/** 
 * Brightkite PHP Object to do basic things such as checkin, post a note, and search
 * for location. 
 *
 * This object is chain-able. 
 * Ex: 
 * Brightkite::factory()->current_location()->note('new note');
 * Brightkite::factory()->address('San Francisco, CA')->checkin()->note('new note');
 * Brightkite::factory()->address('@placemark')->checkin();
 *
 * @author John Barker <jabarker1@gmail.com>
 * @copyright (c) 2009 John Barker 
 */

class Brightkite {

	protected $location;
	protected $last_method;
	
	private $username = '';
	private $password = '';
	
	/**
	 * Factory method to allow for chaining
	 *
	 * @chainable
	 * @return   object
	 */
	public static function factory()
	{
		return new Brightkite;
	}
	
	/**
	 * Sets users current checked in location.
	 *
	 * @chainable
	 */
	public function current_location()
	{
		$data = $this->call('http://brightkite.com/me');
		$this->location = 'http://brightkite.com/places/'.$data->place->id;
		$this->last_method = __FUNCTION__;
		
		return $this;
	}
	
	/**
	 * Searches for address and uses first match.
	 *
	 * @chainable
	 * @param   string   location in form of address, city, etc.
	 * @return  object
	 */
	public function address($loc)
	{
		$this->last_method = __FUNCTION__;
		$data = $this->call('http://brightkite.com/places/search.xml?q='.urlencode($loc));
		
		if (count($data->place) > 1)
		{
			$this->location = $data->place[0]->id;
		}
		else
		{
			$this->location = 'http://brightkite.com/places/'.$data->id;
		}
		
		return $this;
	}
	
	/**
	 * Checks you in with result from address()
	 *
	 * @chainable
	 * @return 	object
	 */
	public function checkin()
	{
		if ($this->last_method == 'current_location')
		{
			throw new Exception('You are attempting to check in to a place you are already checked into.');
		}
		
		$this->last_method = __FUNCTION__;
		$this->call($this->location.'/checkins');
		
		return $this;
	}
	
	/**
	 * Post a note with result from either address()
	 * or current_location().
	 *
	 * @param   string   Note to be sent.
	 */
	public function note($note)
	{
		if (empty($note))
		{
			throw new Exception('You can not post an empty note.');
		}
		
		$this->last_method = __FUNCTION__;
		$this->call($this->location.'/notes', array('note[body]' => $note));
	}
	
	/**
	 * Creates and makes the web service call to Brightkite.
	 *
	 * @param   string   URL to call API
	 * @param   array    params to be passed to WS call
	 * @return  object
	 */
	public function call($url = NULL, $params = NULL)
	{
		$url = ( ! is_null($url)) ? $url : $this->location;
		
		if ($this->last_method != 'address')
		{
			$url = $url.'.xml';
		}
		
		$ch = curl_init();
		
		if (empty($this->username) OR empty($this->password))
		{
			throw new Exception('You must set the username and password properties.');
		}
		
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_USERPWD, $this->username.':'.$this->password);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		
		if (in_array($this->last_method, array('note', 'checkin')))
		{
			curl_setopt($ch, CURLOPT_POST, 1);
			curl_setopt($ch, CURLOPT_POSTFIELDS, $params);
		}
		
		if ( ! $data = curl_exec($ch))
		{
			throw new Exception('Error making WS call: '.curl_error($ch));
		}
		
		return simplexml_load_string($data);
	}
	
	/**
	 * Return current location
	 *
	 * @return   string
	 */
	public function get_location()
	{
		return $this->location;
	}
	
}

try {
	echo Brightkite::factory()->current_location()->note('I can haz n0tez!');
}
catch (Exception $e)
{
	echo $e->getMessage();
}