preserve caps with regexp.replace

dhaywirex · February 29th, 2004, 09:32 PM

hi, i have a function that highlights search keywords

function highlight(text, searchtxt)
if text <> empty and searchtxt <> empty then
  dim regex
  set regex = new regexp

  regex.pattern = searchtxt
  regex.global = true
  regex.ignorecase = true

  highlight = regex.replace(text, "" &
  searchtxt & "")
end if
end function

as you can see, this will allow the search to be case-insensitive, however, this also means that all keywords found in the text will be replace with the search word, e.g. HELLO replaced with hello(search word)
is there anyway to preserve the original text??? HELLO will be highlighted even though the user search for 'hello', and the second heLLo will also be highlighted as it is, anyone any ideas??

joefawcett · March 1st, 2004, 02:54 AM

Untested, you need parentheses around the expression. $1, $2 etc. is the result of the match:

Code:

function highlight(text, searchtxt)        
if text <> empty and searchtxt <> empty then
  dim regex
  set regex = new regexp
  
  regex.pattern = "(" & searchtxt & ")"
  regex.global = true
  regex.ignorecase = true
  
  highlight = regex.replace(text, "$1")
end if
end function

--

Joe

dhaywirex · March 1st, 2004, 10:08 PM

thnks joefawcett

it works bt i dun understand why, how does adding the parentheses helps to preserve the original text, and why would "$1" work, care to explain??

planoie · March 1st, 2004, 11:10 PM

Your original replace statement was this:

highlight = regex.replace(text, "" & searchtxt & "")

In it you are providing the search term (in whatever case was passed into the function call) as the replacement (within your additional HTML) for the found term.

Joe's suggestion:
highlight = regex.replace(text, "$1")

Here, the "$1" is a replacement token for the pattern's first search result found. So, the regex replace method is actually substituting "$1" with the match pattern found. This is a standard feature of regular expression replaces.

Peter
------------------------------------------------------
Work smarter, not harder.

dhaywirex · March 2nd, 2004, 12:25 AM

i see, thnks