Convert geographical coordinates with Triona

gistfile1.aw

<?php

/**
 * Convert coordinates with projection
 *
 * @param string $easting X coordinate
 * @param string $northing Y coordinate
 * @param string $projection
 *
 * @return array
 */
function convert($easting, $northing, $projection) {

    // Service endpoint
    $endpoint = 'http://app.triona.se/proj/project.aspx';

    // Valid projections
    $projections = array(
        'WGS84toRT90',
        'RT90toWGS84',
        'WGS84toUTM32',
        'WGS84toUTM33',
        'WGS84toUTM34',
        'UTM32toWGS84',
        'UTM33toWGS84',
        'UTM34toWGS84',
        'KKJtoWGS84',
        'WGS84toKKJ'
    );

    $return = array();

    if(in_array($projection, $projections)) {
        $url = $endpoint.'?'.http_build_query(array(
            'e' => $easting,
            'n' => $northing,
            'p' => $projection
        ));

        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        if($response = curl_exec($ch)) {
            if(preg_match('/\((.+),(.+)\);$/', $response, $coordinates)) {
                $return = array(
                    'x' => $coordinates[1],
                    'y' => $coordinates[2]
                );
            }
        }
        curl_close($ch);
    }
    else {
        throw new Exception('Invalid projection "'.$projection.'".');
    }

    return $return;
}

/**
 * Testing
 *
 */
echo '<pre>';
print_r(convert('598024', '6642787', 'UTM32toWGS84'));

Outputs:

Array
(
    [x] => 10.7528310482097
    [y] => 59.9109098384598
)