How to Remove special characters from name-value pairs in the Webspeed URL?

Question

I need to remove carriage return and linefeed characters that are present in Webspeed URL containing name-value pairs..How can that be done? any ideas please!

Answer 1

I have recently had a need to do something like this and found the following to be quite handy. This might be a bit drastic -- it removes all control codes and anything higher than ascii 126. But you can adjust those limits easily enough. (My usage is to populate text fields -- so all of that stuff is illegal input for me.)

define variable hd as character no-undo initial "0123456789ABCDEF".

function hex2char returns character ( h as character ):

  define variable i as integer no-undo.

  if length( h ) <> 2 or index( hd, substring( h, 1, 1 )) < 0 or index( hd, substring( h, 2, 1 )) < 0 then
    return "".

  i = ((( index( hd, substring( h, 1, 1 )) - 1 ) * 16 ) +
          index( hd, substring( h, 2, 1 )) - 1
      ).

  if i < 32 or i >= 127 then
    return "".
   else
    return chr( i ).

end.

function url-decode returns character ( input url as character ):

  define variable xurl as character no-undo.
  define variable zurl as character no-undo.

  define variable pct as integer no-undo.

  /* fix known trouble makers
   */

  assign
    xurl = replace( url, "+", " " )
    xurl = replace( xurl, "%0A%0D", "~n" )      /* <LF><CR>     */
    xurl = replace( xurl, "%0D%0A", "~n" )      /* <CR><LF>     */
    xurl = replace( xurl, "%0D",    "~n" )      /* <CR>         */
  .

  pct  = index( xurl, "%" ).

  do while pct > 0 and xurl > "":
    assign
      zurl = zurl + substring( xurl, 1, pct - 1 ) + hex2char( substring( xurl, pct + 1, 2 ))
      xurl = substring( xurl, pct + 3 )
      pct  = index( xurl, "%" )
    .
  end.

  return zurl + xurl.

end.

display url-decode( sampleUrl ) view-as editor size 60 by 25.

Answer 2

To replace characters you can use the REPLACE function

REPLACE function
Returns a string with specified substring replacements.
Syntax 
REPLACE ( source-string , from-string , to-string ) 

Example:

DEFINE VARIABLE cTxt    AS CHARACTER   NO-UNDO FORMAT "x(20)".
DEFINE VARIABLE cNewTxt AS CHARACTER   NO-UNDO FORMAT "x(20)".

cTxt = "abc123abc123abc123".

cNewTxt = REPLACE(cTxt, "a", "-").

DISPLAY cNewTxt .

You could target new lines using the control code ~n

REPLACE(cString, "~n", "replacing character").

Or target the individual %0d (decimal ascii code 13) and %0a's (decimal ascii code 10).

REPLACE(cString, CHR(13), "replacing character").
REPLACE(cString, CHR(10), "replacing character").