extension.driver.php

<?php
	
	class Extension_GeocodingField extends Extension {

	/*-------------------------------------------------------------------------
		Definition:
	-------------------------------------------------------------------------*/
		
		protected static $fields = array();
		
		public function uninstall() {
			if(parent::uninstall() == true){
				Symphony::Database()->query("DROP TABLE `tbl_fields_geocoding`");
				return true;
			}

			return false;
		}
		
		public function install() {
			try {
				Symphony::Database()->query("
					CREATE TABLE IF NOT EXISTS `tbl_fields_geocoding` (
						`id` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
						`field_id` INT(11) UNSIGNED NOT NULL,
						`expression` VARCHAR(255) DEFAULT NULL,
						`hide` ENUM('yes', 'no') DEFAULT 'no',
						PRIMARY KEY (`id`),
						KEY `field_id` (`field_id`)
					) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
				");
			} catch (Exception $e) {
				return false;
			}

			return true;
		}
		
		public function update($previousVersion){
			if (version_compare($previousVersion, '0.7', '<')) {

				Symphony::Configuration()->remove('geocoding-field');
				Administration::instance()->saveConfig();
			}

			return true;
		}
		
		public function getSubscribedDelegates() {
			return array(
				array(
					'page'		=> '/publish/new/',
					'delegate'	=> 'EntryPostCreate',
					'callback'	=> 'compileBackendFields'
				),
				array(
					'page'		=> '/publish/edit/',
					'delegate'	=> 'EntryPostEdit',
					'callback'	=> 'compileBackendFields'
				),
				array(
					'page'		=> '/frontend/',
					'delegate'	=> 'EventPostSaveFilter',
					'callback'	=> 'compileFrontendFields'
				),
			);
		}
		
	/*-------------------------------------------------------------------------
		Utilities:
	-------------------------------------------------------------------------*/
		
		public function getXPath($entry) {
			$entry_xml = new XMLElement('entry');
			$data = $entry->getData();
			$fields = array();
			
			$entry_xml->setAttribute('id', $entry->get('id'));
			
			$associated = $entry->fetchAllAssociatedEntryCounts();
			
			if (is_array($associated) and !empty($associated)) {
				foreach ($associated as $section => $count) {
					$handle = Symphony::Database()->fetchVar('handle', 0, "
						SELECT
							s.handle
						FROM
							`tbl_sections` AS s
						WHERE
							s.id = '{$section}'
						LIMIT 1
					");
					
					$entry_xml->setAttribute($handle, (string)$count);
				}
			}
			
			// Add fields:
			foreach ($data as $field_id => $values) {
				if (empty($field_id)) continue;
				
				$field = FieldManager::fetch($field_id);
				$field->appendFormattedElement($entry_xml, $values, false, null);
			}
			
			$xml = new XMLElement('data');
			$xml->appendChild($entry_xml);
			
			$dom = new DOMDocument();
			$dom->strictErrorChecking = false;
			$dom->loadXML($xml->generate(true));
			
			$xpath = new DOMXPath($dom);
			
			if (version_compare(phpversion(), '5.3', '>=')) {
				$xpath->registerPhpFunctions();
			}
			
			return $xpath;
		}
		
		/*
			Modified from:
			http://www.kevinbradwick.co.uk/developer/php/free-to-script-to-calculate-the-radius-of-a-coordinate-using-latitude-and-longitude
		*/
		public static function geoRadius($lat, $lng, $rad, $kilometers=false) {
			$radius = ($kilometers) ? ($rad * 0.621371192) : $rad;

			(float)$dpmLAT = 1 / 69.1703234283616;

			// Latitude calculation
			(float)$usrRLAT = $dpmLAT * $radius;
			(float)$latMIN = $lat - $usrRLAT;
			(float)$latMAX = $lat + $usrRLAT;

			// Longitude calculation
			(float)$mpdLON = 69.1703234283616 * cos($lat * (pi/180));
			(float)$dpmLON = 1 / $mpdLON; // degrees per mile longintude
			$usrRLON = $dpmLON * $radius;

			$lonMIN = $lng - $usrRLON;
			$lonMAX = $lng + $usrRLON;

			return array("lonMIN" => $lonMIN, "lonMAX" => $lonMAX, "latMIN" => $latMIN, "latMAX" => $latMAX);
		}

		/*
		Calculate distance between two lat/long pairs
		*/
		public static function geoDistance($lat1, $lon1, $lat2, $lon2, $unit) {
			$theta = $lon1 - $lon2;
			$dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) +  cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
			$dist = acos($dist);
			$dist = rad2deg($dist);
			$miles = $dist * 60 * 1.1515;

			$unit = strtolower($unit);

			$distance = 0;

			if ($unit == "k") {
				$distance = ($miles * 1.609344);
			} else if ($unit == "n") {
				$distance = ($miles * 0.8684);
			} else {
				$distance = $miles;
			}

			return round($distance, 1);
		}

		public function registerField($field) {
			self::$fields[] = $field;
		}

	/*-------------------------------------------------------------------------
		Delegates:
	-------------------------------------------------------------------------*/

		public function compileBackendFields($context) {
			foreach (self::$fields as $field) {
				$field->compile($context['entry']);
			}
		}

		public function compileFrontendFields($context) {
			foreach (self::$fields as $field) {
				$field->compile($context['entry']);
			}
		}

	}