text: from django import template
  from mapfeed.models import MapPath, MapStation
  
  register = template.Library()
  
  #provide sequenced order of stations
  def draw_line(line):
      seq_sta = []
      paths = MapPath.objects.filter(line__id=line.id).order_by('seq_num')
      for p in paths:
          station = MapStation.objects.get(id=p.station.id)
          seq_sta.append(station)
      return {
          'seq_sta' : seq_sta,
          'line' : line,
      }
  register.inclusion_tag('mapfeed/path_draw.html')(draw_line)
  
  #determine line order for drawing
  @register.filter
  def determine_line_order(line, station):
      order = 1
      paths = MapPath.objects.filter(station__id=station.id).order_by('line')
      #iterates through each path segment, compares to line given
      for p in paths:
          if line.id == p.line.id:
              return order
          order = order + 1
      return 0
  
  #returns the next station given a specific key
  @register.filter
  def next_station_x(list, key):
      try:
          station = list[key+1]
      except Exception as e:
          station = list[key]
      return station.x_coord
  
  @register.filter
  def next_station_y(list, key):
      try:
          station = list[key+1]
      except Exception as e:
          station = list[key]
      return station.y_coord
  
  @register.filter
  def next_station_num_lines(list, key):
      try:
          station = list[key+1]
      except Exception as e:
          station = list[key]
      return station.lines.count
  
  @register.filter
  def next_station_name(list, key):
      try:
          station = list[key+1]
      except Exception as e:
          station = list[key]
      return station.station_name
  