Passing Files as Parameters

Hi,

With V7 approaching our shop and realizing I haven't yet put into practice much of the V6.1 enhancements, I was looking at Passing Files as Parameters. I have an example from systemideveloper by Paul Tuohy, but I'm not fully appreciating the advantages of this feature. Would that be that it permits having all file operations in the callee? With the file having to be declared in both caller and callee, I don't really get the advantage.

Also, WHAT exactly is being passed as the first parameter? Why is the file template not in the caller instead of the callee? What's the advantage over declaring the files in both caller and callee and passing only 2 parameters, the key and the record? Thanks!


Caller :
FcustMast IF E K Disk

D custRecord DS LikeRec(custRec)
D GetCustData Pr N
D custFile LIKEFILE(custMast)
D custData LikeRec(custRec)
D custKey Like(custNum)

/Free
If GetCustData(custMast: custRecord: 'TESTKEY')

/end-free


Called procedure :
FcustMast IF E K Disk TEMPLATE

P GetCustData B
D GetCustData PI N
D custFile LIKEFILE(CustMast)
D custData LikeRec(CustRec)
D custKey Like(custData.CustNum)

/Free
Read custKey CustFile custData;
If %Found(custMast);
Return *On;
Else;
Return *Off;
EndIf;
/end-free