From the DOM to Paradox

• With many DTDs, including RSS, some nodes are optional. A direct consequence is that any selection operation, whether done directly via a DOM API or via an XPath expression, can fail.
• Accordingly, to select a node, one must always take exceptions into account:

  var 
    tci              TCursor
    i, len, errcount LongInt
    oNode            OleAuto
    s, des           String
    oDes             OleAuto
    endVar
  
  [...]  
  len = nl.length
  lbStatus.Value = "This feed contains " + String(len) + " items." ; lbStatus is a Text control
  pb.setRangeAndStep (0, len - 1, 1) ; pb is a ProgressBar control
  s = ""
  tci.attach (TITEM) ;  TITEM is a TableFrame
  tci.edit ()
  for i from 0 to len - 1
    pb.pos = i
    errcount = 0
    onode = nl^item (i)
    tci.insertBeforeRecord ()
    try
      odes = onode^selectSingleNode ("description")
      des = odes^Text
    onfail
      des = "(article sans description)"
      errcount = 1
      endtry
    tci.DETITEM = des
  [...]