SemanticMaps/includes/SM_AreaValueDescription.php

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<?php

class SMAreaValueDescription extends SMWValueDescription {
        
        protected $bounds = false;

        public function __construct( SMWDataItem $dataItem, $comparator, $radius ) {
                parent::__construct( $dataItem, $comparator );  

                // Only if the MapsGeoFunctions class is  loaded, we can create the bounding box.
                if ( self::geoFunctionsAreAvailable() ) {
                        $this->calculateBounds( $dataItem, $radius );
                }
        }

        protected function calculateBounds( SMWDIGeoCoord $dataItem, $radius ) {
                $this->bounds = self::getBoundingBox(
                        array( 'lat' => $dataItem->getLatitude(), 'lon' => $dataItem->getLongitude() ),
                        MapsDistanceParser::parseDistance( $radius )
                );              
        }
        
        public function getQueryString( $asValue = false ) {
                if ( $this->getDataItem() !== null ) {
                        $queryString = SMWDataValueFactory::newDataItemValue( $this->getDataItem(), $this->m_property )->getWikiValue();
                        return $asValue ? $queryString : "[[$queryString]]";
                } else {
                        return $asValue ? '+' : '';
                }
        }

    public function prune( &$maxsize, &$maxdepth, &$log ) {
        if ( ( $maxsize < $this->getSize() ) || ( $maxdepth < $this->getDepth() ) ) {
                        $log[] = $this->getQueryString();
                        
                        $result = new SMWThingDescription();
                        $result->setPrintRequests( $this->getPrintRequests() );
                        
                        return $result;
                } else {
                        $maxsize = $maxsize - $this->getSize();
                        $maxdepth = $maxdepth - $this->getDepth();
                        return $this;
                }
    }
    
    public function getBounds() {
        return $this->bounds;
    }    
        
        public function getSQLCondition( $tableName, array $fieldNames, $dbs ) {
                // Only execute the query when the description's type is geographical coordinates,
                // the description is valid, and the near comparator is used.
                if ( $this->getDataItem()->getDIType() != SMWDataItem::TYPE_GEO
                        || ( $this->getComparator() != SMW_CMP_EQ && $this->getComparator() != SMW_CMP_NEQ )
                        ) {
                        return false;
                }
                
                $north = $dbs->addQuotes( $this->bounds['north'] );
                $east = $dbs->addQuotes( $this->bounds['east'] );
                $south = $dbs->addQuotes( $this->bounds['south'] );
                $west = $dbs->addQuotes( $this->bounds['west'] );

                $isEq = $this->getComparator() == SMW_CMP_EQ;
                
        $conditions = array();

        $smallerThen = $isEq ? '<' : '>=';
        $biggerThen = $isEq ? '>' : '<=';
        $joinCond = $isEq ? 'AND' : 'OR';

        $conditions[] = "{$tableName}.$fieldNames[0] $smallerThen $north";
        $conditions[] = "{$tableName}.$fieldNames[0] $biggerThen $south";
        $conditions[] = "{$tableName}.$fieldNames[1] $smallerThen $east";
        $conditions[] = "{$tableName}.$fieldNames[1] $biggerThen $west";

        $sql = implode( " $joinCond ", $conditions );

                return $sql;
        }

        protected static function getBoundingBox( array $centerCoordinates, $circleRadius ) {
                $north = MapsGeoFunctions::findDestination( $centerCoordinates, 0, $circleRadius );
                $east = MapsGeoFunctions::findDestination( $centerCoordinates, 90, $circleRadius );
                $south = MapsGeoFunctions::findDestination( $centerCoordinates, 180, $circleRadius );
                $west = MapsGeoFunctions::findDestination( $centerCoordinates, 270, $circleRadius );

                return array(
                        'north' => $north['lat'],
                        'east' => $east['lon'],
                        'south' => $south['lat'],
                        'west' => $west['lon'],
                );
        }
        
        protected static function geoFunctionsAreAvailable() {
                return class_exists( 'MapsGeoFunctions' );
        }       
        
}

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