[Typo3] SESSIONTROUBLE.....getKey(), setKey().....but "updateKey()" ??

[matthi]

Hi,

this is driving me nuts for a few days now and I am not able to find the 
  required information.

In an extension I want to have a multipage form and so collecting all 
the data from the various pages to take it through the whole form

I get sucessfully stored the data from page one:

$GLOBALS["TSFE"]->fe_user->setKey("user","myData", $myVars);

So far,so good..

Now the problem is, how to update $myData  ?

If in page2 I recall $GLOBALS["TSFE"]->fe_user->setKey("user","myData", 
$myVars); to store the values of this formPart I overwrite the so far 
called data...no surprise at all, but how can I handle that ?

Also I tried to set up a new key for form2, but that hasnt worked for 
the one or other reason and even if it would, I dont like the idea to 
have as many keys as I have formParts.

So, what I am missing is something like 
$GLOBALS["TSFE"]->fe_user->updateKey("user","myData", $myVars);

Its nice to have this setKey and getKey stuff, but I wonder which sense 
are making sessionVars if you can´t update them.....as I think that the 
change is one of the keycharacteristics SESSIONSVARS have

Well, hold on, I am sure you can, and tt_products does, even if it needs 
a lot of lines of code to do so, to much for my taste and right now I 
just don´t get the trick

Hopefully there is an "easy" overseen way to update SESSIONvars

Thanks

Matthias Oesterle