parseKmlFromAssets function

Implementation

Future<List<LatLng>> parseKmlFromAssets(String assetPath) async {
  // Load the KML file as a string from the asset path provided
  final xmlString = await rootBundle.loadString(assetPath);

  // Initialize an empty list to store the parsed coordinates as LatLng objects
  List<LatLng> path = [];

  // Regular expression to find all <coordinates> tags and capture the content between them
  RegExp exp = RegExp(r'<coordinates[^>]*>(.*?)<\/coordinates>', dotAll: true);

  // Find all matches of the regular expression in the XML string
  var matches = exp.allMatches(xmlString);

  // Loop through all matches (each match represents a set of coordinates)
  for (var match in matches) {
    // Extract the coordinate string from the match (group 1 captures the contents of the <coordinates> tag)
    String coordinateString = match.group(1) ?? "";

    // Split the coordinate string into individual coordinate pairs (separated by whitespace)
    List<String> coordinatePairs = coordinateString.split(RegExp(r'\s+'));

    // Loop through each coordinate pair
    for (String pair in coordinatePairs) {
      // Split the coordinate pair into individual components (longitude, latitude, and possibly altitude)
      List<String> coords = pair.split(',');

      // Check if the pair contains at least a longitude and latitude
      if (coords.length >= 2) {
        // Try to parse the longitude and latitude as double values
        double? longitude = double.tryParse(coords[0].trim());
        double? latitude = double.tryParse(coords[1].trim());

        // If both latitude and longitude are valid numbers, add them as a LatLng object to the path list
        if (latitude != null && longitude != null) {
          path.add(LatLng(latitude, longitude));
        }
      }
    }
  }

  // Return the list of parsed LatLng objects
  return path;
}