reading CSV text file

[Ken Ray]

On Fri, 22 Jun 2007 21:36:21 +0000, runrev260805 at m-r-d.de wrote:

> Hi,
> 
> i have to read a textfile, which is comma separated and contains " as 
> text identifier. The item delimiter is ,
> My problem is, i do not know, how can i read the file and detect each 
> item of a line, as the items are sepearated by comma and the 
> textfield/items could contain comma, too. How can i tell Revolution 
> to ignore the comma in the "tesxtarea of an item"

Others have commented on how terrible CSV is, so I won't add my own 
loathing of the format. However, if you MUST deal with CSV, Alex 
Tweedly and Richard Gaskin came up with a reasonably speedy 
implementation a few years back the converts CSV data to tab-delimited 
format (which you can then parse at your leisure):

function CSV2Tab3 pData
   local tNuData -- contains tabbed copy of data
   local tReturnPlaceholder -- replaces cr in field data to avoid line 
breaks which would be
   --                                     misread as records; replaced 
later during display
   local tEscapedQuotePlaceholder -- used for keeping track of quotes 
in data
   local tInQuotedText -- flag set while reading data between quotes
   --
   put numtochar(11) into tReturnPlaceholder -- vertical tab as 
placeholder
   put numtochar(2)  into tEscapedQuotePlaceholder -- used to simplify 
distinction between
   
--                                                                         
quotes in data and those in delimiters
   --
   -- Normalize line endings:
   replace crlf with cr in pData          -- Win to UNIX
   replace numtochar(13) with cr in pData -- Mac to UNIX
   --
   -- Put placeholder in escaped quote (non-delimiter) chars:
   replace ("\"&quote) with tEscapedQuotePlaceholder in pData
   replace quote&quote with tEscapedQuotePlaceholder in pData --<NEW
   --
   put space before pData   -- to avoid ambiguity of starting context
   split pData by quote
   put False into tInsideQuoted
   put 0 into tCounter
   repeat for each line tKey in (the keys of pData)
     add 1 to tCounter
     put pData[tCounter] into k
     if (tInsideQuoted) then
       replace cr with tReturnPlaceholder in k
       put k after tNuData
       put False into tInsideQuoted
     else
       replace comma with tab in k
       put k after tNuData
       put true into tInsideQuoted
     end if
   end repeat
   --
   delete char 1 of tNuData -- remove the leading space
   replace tEscapedQuotePlaceholder with quote in tNuData
   return tNuData
end CSV2Tab3


Ken Ray
Sons of Thunder Software, Inc.
Email: kray at sonsothunder.com
Web Site: http://www.sonsothunder.com/