function createGeoJSON($layer_tablename,$column_names,$file='',$Fixed_Columns='',$projection='900913'){
require_once 'json/include_geom.php';
require_once 'json/geojson.php';
require_once 'json/wkt.php';
if ($Fixed_Columns == '') {
$Fixed_Columns = AUTO_DBCOL_PREFIX."id, astext(ST_Transform(".AUTO_DBCOL_PREFIX."topology,". $projection .")) as topology, ";
}
$total_column_names = $Fixed_Columns . $column_names;
$sql = 'select '.$total_column_names.' from "'. $layer_tablename . '"';
$query_args = array($total_column_names, $layer_tablename);
$strgeoJSON='{"type": "FeatureCollection", "features": [';
$str='';
$arr = explode(",",$column_names);
$cnt = count($arr);
$data = db_query($sql);
while($layer_obj = db_fetch_object($data)){
$geom_wkt = $layer_obj->topology;
$wkt = new WKT();
$geom = $wkt->read($geom_wkt);
$strgeoJSON .= '{"geometry": ' . json_encode($geom->getGeoInterface()) . ', ';
$strgeoJSON .= '"type": "Feature", ';
$strgeoJSON .= '"id": '.$layer_obj->{AUTO_DBCOL_PREFIX."id"}.', ';
$strgeoJSON .= '"properties": {';
for($i=0;$i<$cnt;$i++){
$strgeoJSON .= '"'. trim($arr[$i]) .'": "' . $layer_obj->$arr[$i] .'",';
}
$strgeoJSON = substr_replace($strgeoJSON,"",-1);
$strgeoJSON .= '}},';
}
$strgeoJSON = substr_replace($strgeoJSON,"",-1);
$strgeoJSON .= ']}';
if ($file != '') {
$myFile = $file;
}else{
$myFile = "json/".$layer_tablename .".json";
}
$fh = fopen($myFile, 'w') or die("can't open file");
fwrite($fh, $strgeoJSON);
fclose($fh);
return $myFile;
}
/**
* Read WKT string into geometry objects.
*
* @param string $text A WKT string.
*
* @return Geometry|GeometryCollection.
*/
function treasurehunt_wkt_to_object($text)
{
$wkt = new WKT();
return $wkt->read($text);
}
