function weather_get_metar in Weather 6.5

Same name and namespace in other branches

1. 5.6 weather.module \weather_get_metar()
2. 5 weather.module \weather_get_metar()
3. 7 weather.module \weather_get_metar()

Fetches the latest METAR data from the database or internet

2 calls to weather_get_metar()

weather_block in ./weather.module

Generate HTML for the weather block

weather_search_location in ./weather.module

Searches for the specified location, whether it is a place name or an ICAO code. For example, weather/fuhlsbüttel will display the weather for Hamburg-Fuhlsbüttel.

File

./weather.module, line 2015

Display <acronym title="METeorological Aerodrome Report">METAR</acronym> weather data from anywhere in the world

Code

function weather_get_metar($icao) {

  // See if there's a report in the database
  $icao = strtoupper($icao);
  $sql = "SELECT * FROM {weather} WHERE icao='%s'";
  $result = db_query($sql, $icao);
  $data = db_fetch_array($result);

  // If there is no report, initialize the array
  if (!isset($data['next_update_on'])) {
    $data['next_update_on'] = 0;
  }

  // If the time has come, try to download again
  if ($data['next_update_on'] <= time()) {
    $metar_raw = _weather_retrieve_data($icao);
    if ($metar_raw) {
      $metar = weather_parse_metar($metar_raw);

      // Calculate the next scheduled update. Use 62 minutes after the
      // reported timestamp, to allow the data to propagate to the server.
      $data['next_update_on'] = $metar['reported_on'] + 62 * 60;

      // However, if the current time is more than 62 minutes
      // over the reported timestamp, do not download on every page request.
      // Therefore, we use 3, 6, 12, and 24 hours to check for updates.
      // From then on, we check once a day for updates.
      if ($data['next_update_on'] < time()) {
        $last_update = $metar['reported_on'];
        $hours = 3 * 60 * 60;
        while ($last_update + $hours + 120 < time()) {
          if ($hours < 86400) {
            $hours = $hours * 2;
          }
          else {
            $hours = $hours + 86400;
          }
        }

        // Add 2 minutes to allow the data to propagate to the server.
        $data['next_update_on'] = $last_update + $hours + 120;
      }
      weather_store_metar($metar, $data['next_update_on']);
    }
    else {

      // The download has not been successful. Calculate the time of next update
      // according to last tries.
      if (empty($data['metar_raw'])) {

        // There is no entry yet, so this is the first download attempt.
        // Create a new entry and store the current time in the metar_raw column.
        $metar['icao'] = $icao;
        $metar['#raw'] = gmdate("dHi") . "Z";
        $next_update_on = time() + 10 * 60;
        weather_store_metar($metar, $next_update_on);
      }
      else {

        // There has been at least one download attempt. Increase the time of
        // next update to not download every few minutes.
        // If 24 hours are reached, we check once a day for updates.
        // This way, we gracefully handle ICAO codes which do no longer exist.
        // The time of the last download attempt is stored in the metar_raw column.
        $metar = weather_parse_metar($data['metar_raw']);
        $last_update = $metar['reported_on'];
        $hours = 3 * 60 * 60;
        while ($last_update + $hours + 120 < time()) {
          if ($hours < 86400) {
            $hours = $hours * 2;
          }
          else {
            $hours = $hours + 86400;
          }
        }

        // Add 2 minutes to allow the data to propagate to the server.
        $next_update_on = $last_update + $hours + 120;
        $metar['icao'] = $icao;
        $metar['#raw'] = $data['metar_raw'];
        weather_store_metar($metar, $next_update_on);
      }
    }
  }
  else {
    $metar = weather_parse_metar($data['metar_raw']);
  }
  return $metar;
}