googleWeather.php

<?php

	/**
	 * Grabs weather data from Google.com's weather API and return a nicely formatted array
	 *
	 * @author Ashwin Surajbali
	 */
	class googleWeather{

		/**
		 * Zipcode
		 *
		 * @var int
		 */
		public $zip;

		/**
		 * Disable or enable caching
		 *
		 * @var boolean
		 */
		public $enable_cache = 0;

		/**
		 * Path to your cache directory
		 * eg. /www/website.com/cache
		 *
		 * @var string
		 */
		public $cache_path = '';

		/**
		 * Cache expiration time in seconds
		 * Default: 3600 = 1 Hour
		 * If the cached file is older than 1 hour, new data is fetched
		 *
		 * @var int
		 */
		public $cache_time = 3600; // 1 hour

		/**
		 * Location of the weather icons on googles server
		 * They keep changing this, so alter as necessary
		 *
		 * @var unknown_type
		 */
		public $icons_url = 'http://g0.gstatic.com';

		/**
		 * Full location of the cache file
		 *
		 * @var string
		 */
		private $cache_file;

		/**
		 * Location of the google weather api
		 *
		 * @var string
		 */
		private $gweather_api_url = 'http://www.google.com/ig/api?weather=';

		/**
		 * Storage var for data returned from curl request to the google api
		 *
		 * @var string
		 */
		private $raw_data;

		/**
		 * Pull weather information for 'Zipcode' passed in
		 * If enable_cache = true, data is cached and refreshed every hour
		 * Weather data is returned in an associative array
		 *
		 * @param int $zip
		 * @return array
		 */
		public function get_weather_data($zip = null){

			$zip = trim($zip);

			if (!$zip || strlen($zip) < 5 || !is_numeric($zip)){
				die('Invalid zip code.');
			}else{
				$this->zip = $zip;
			}

			if ($this->enable_cache && !empty($this->cache_path)){
				$this->cache_file = $this->cache_path . '/' . $this->zip;
				return $this->load_from_cache();
			}

			$this->gweather_api_url = $this->gweather_api_url . $this->zip;

			if ($this->make_request()){

				$xml = new SimpleXMLElement($this->raw_data);

				$return_array = array();

				$return_array['forecast_info']['city'] = $xml->weather->forecast_information->city['data'];
				$return_array['forecast_info']['zip'] = $xml->weather->forecast_information->postal_code['data'];
				$return_array['forecast_info']['date'] = $xml->weather->forecast_information->forecast_date['data'];
				$return_array['forecast_info']['date_time'] = $xml->weather->forecast_information->current_date_time['data'];

				$return_array['current_conditions']['condition'] = $xml->weather->current_conditions->condition['data'];
				$return_array['current_conditions']['temp_f'] = $xml->weather->current_conditions->temp_f['data'];
				$return_array['current_conditions']['temp_c'] = $xml->weather->current_conditions->temp_c['data'];
				$return_array['current_conditions']['humidity'] = $xml->weather->current_conditions->humidity['data'];
				$return_array['current_conditions']['icon'] = $this->icons_url . $xml->weather->current_conditions->icon['data'];
				$return_array['current_conditions']['wind'] = $xml->weather->current_conditions->wind_condition['data'];

				for ($i = 0; $i < count($xml->weather->forecast_conditions); $i++){
					$data = $xml->weather->forecast_conditions[$i];
					$return_array['forecast'][$i]['day_of_week'] = $data->day_of_week['data'];
					$return_array['forecast'][$i]['low'] = $data->low['data'];
					$return_array['forecast'][$i]['high'] = $data->high['data'];
					$return_array['forecast'][$i]['icon'] = $this->icons_url . $data->icon['data'];
					$return_array['forecast'][$i]['condition'] = $data->condition['data'];
				}

			}

			if ($this->enable_cache && !empty($this->cache_path)){
				$this->write_to_cache($return_array);
			}

			return $return_array;

		}

		private function load_from_cache(){

			if (file_exists($this->cache_file)){

				$file_time = filectime($this->cache_file);
				$now = time();
				$diff = ($now-$file_time);

				if ($diff <= $this->cache_time){
					return unserialize(file_get_contents($this->cache_file));
				}
			}

		}

		private function write_to_cache($data){

			if (!file_exists($this->cache_path)){
				// attempt to make the dir
				mkdir($this->cache_path, 0777);
			}

			if (!file_put_contents($this->cache_file, serialize($data))){
				echo "<br />Could not save data to cache. Please make sure your cache directory exists and is writable.<br />";
			}
		}

		private function make_request(){

			$ch = curl_init();
			curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
			curl_setopt ($ch, CURLOPT_URL, $this->gweather_api_url);
			curl_setopt($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
			curl_setopt ($ch, CURLOPT_TIMEOUT, 60);
			curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
			$this->raw_data = curl_exec ($ch);
			curl_close ($ch);

			if (empty($this->raw_data)){
				return false;
			}else{
				return true;
			}

		}

	}