function farm_sensor_area_sensors in farmOS 7

Load an array of sensors in an area.

Parameters

int $area_id: The area id.

string $type: The sensor type (optional).

Return value

array Returns an array of sensors in the area.

File

modules/farm/farm_sensor/farm_sensor.module, line 367

Code

function farm_sensor_area_sensors($area_id, $type = '') {

  // Start with a blank array.
  $sensors = array();

  // Build a query for sensor assets in the area.
  $query = db_select('farm_asset', 'fa');
  $query
    ->addField('fa', 'id');
  $query
    ->condition('fa.type', 'sensor');

  // Build a sub-select query for determining the latest movement log of assets.
  $subquery = farm_movement_asset_movement_query('fa.id');

  // Join the latest movement log for each asset.
  $query
    ->join('log', 'l', 'l.id = (' . $subquery . ')');

  // Only show assets with a movement to this area.
  $query
    ->join('field_data_field_farm_move_to', 'fdffmt', 'l.id = fdffmt.entity_id');
  $query
    ->condition('fdffmt.field_farm_move_to_tid', $area_id);

  // If a sensor type is specified in the arguments, only show that type.
  if (!empty($type)) {
    $query
      ->join('farm_sensor', 'fs', 'fa.id = fs.id');
    $query
      ->condition('fs.type', $type);
  }

  // Execute the query.
  $result = $query
    ->execute();

  // Load the sensors.
  while ($asset_id = $result
    ->fetchField()) {
    $sensors[] = farm_asset_load($asset_id);
  }

  // Return the sensors.
  return $sensors;
}