class LocationDataReader(object):
   def __init__(self, uri, parent):
      self.uri = uri
      self.parent = parent

      self.title = None
      self.uripattern = None
      self.tabnames = {}
      self.places = {}

      self.parse()

   def openuri(self, uri=None):
      if uri is None:
         uri = self.uri

      try: self.u = urllib.urlopen(uri)
      except Exception, e:
         msg = 'That URI produced an error: %r. Restarting.'
         appuifw.note(msg % e, 'error')
         return

   def getline(self): 
      while 1: 
         try: rawline = self.u.next()
         except StopIteration: return None # thanks deltab
         if not rawline.startswith('#'): break
      return rawline.rstrip()

   def head(self): 
      self.title = unicode(self.getline())
      self.urlpattern = self.getline()

      for item in self.getline().split('\t'):
         longname, area = item.split('::', 1)
         self.places[area] = {}
         self.tab[area] = unicode(longname)

   def safehead(self): 
      try: self.head()
      except Exception, e:
         msg = 'This file is invalid and raised the error: %r'
         appuifw.note(msg % e, 'error')
         self.parent.restart()

   def body(self):
      while 1:
         line = self.getline()
         if line is None: break
         try:
            area, camera, name = line.split('\t', 2)
            self.places[area][camera] = unicode(name)
            appuifw.app.body.add(u'.')
         except:
            msg = u'\nThe following line is ill formed: %s' % line
            appuifw.app.body.add(msg)

   def parse(self):
      self.openuri()
      self.safehead()
      self.body()