Recording rules are a powerful way of enhancing the recorders ability to perform a multitude of customizations while recording to save time while scripting.  Parsing recording rules search in-data for a replacement string and if found, will substitute that string with a variable and place the necessary parsing function in the script.  This article relates specifically to the use of regular expressions as search parameters. 

The OnlyIfCompleteResult attribute specifies that a replacement should be scripted only if a complete string to be scripted can be replaced with a single variable. If false, replacements are scripted when a rule hit is a substring of the string to be scripted.  

This is a sample cookie to be parsed:


If the parse should replace the whole cookie (so as to look like this: WebCookieSet(sCookie);) then the OnlyIfCompleteResult would need to be set to true.  However if the cookie should only be partly replaced (WebCookieSet("authcode_zero="+sCookie);) then OnlyIfCompleteResult should be set to false.

From the recorders perspective, the cookie mentioned above is a complete string.  The recorder does not recognise the left side (authcode_zero=) and the right side (eJxTMTS3TUCCsByhoa2yaDaB...) and so OnlyIfCompleteResult means only customize the value if the whole value can be replaced with a single variable.