In this article I decided to accumulate some knowledge regarding default.lgf scripts.
Purpose of default.lgf:
To perform calculations triggered by user data send by some input schedule or journal. It can be also launched (if user selects the option) at the end of some standard DM chains (Copy, Move, Import, etc..).
For DM chains like DEFAULT_FORMULAS used to run scripts the default.lgf is NOT triggered.
Scope of default.lgf
When launched the default.lgf will receive scope as a combination of all members of all dimensions of data sent by user.
Example:
Dimension: DIM1
Members: D1M1, D1M2
Dimension: DIM2
Members: D2M1, D2M2
Input form (all intersections in the cube has value 1):
The user decided to change value in the cells marked with yellow to 2:
2 values (D1M1,D2M1) and (D1M2,D2M2) will be sent to the cube.
As a result the scope will be a combination of the following members: D1M1,D2M1,D1M2,D2M2
Generating 4 possible combinations:
Sent by user: (D1M1,D2M1); (D1M2,D2M2) and extra: (D1M2,D2M1) and (D1M1,D2M2)
4 values will be processed by default.lgf.
If the default.lgf is like:
*WHEN ACCOUNT //or any dimension
*IS * //any member
*REC(EXPRESSION=%VALUE%+1)
*ENDWHEN
The result will be:
It means, that some extra combinations of members will be processed by default.lgf, not only changed data.
General rules:
1. Don't use *XDIM_MEMBERSET/*XDIM_ADDMEMBERSET in the default.lgf, do not redefine the scope. The original scope (not huge by the way) have to be processed.
2. *XDIM_FILTER can be used sometimes to narrow the scope, but there are some side effects.
3. Use *IS criteria in *WHEN/*ENDWHEN loop to select members for some calculations.
If you have to calculate some function, like:
Result = Func([SomeDim].[Member1],[SomeDim].[Member2],..,[SomeDim].[MemberN]) (N members total)
And store the Result in some member, then you have to write N *WHEN/*ENDWHEN loops to prevent aggregation if more then 1 member is in scope. Without multiple loops the result will be multiplied M times, where M is number of different members sent by input form simultaneously.
Example (multiply 3 members):
*WHEN SomeDim
*IS Member1
*REC(EXPRESSION=%VALUE%*[SomeDim].[Member2]*[SomeDim].[Member3],SomeDim=ResultMember)
*ENDWHEN
*WHEN SomeDim
*IS Member2
*REC(EXPRESSION=%VALUE%*[SomeDim].[Member1]*[SomeDim].[Member3],SomeDim=ResultMember)
*ENDWHEN
*WHEN SomeDim
*IS Member3
*REC(EXPRESSION=%VALUE%*[SomeDim].[Member1]*[SomeDim].[Member1],SomeDim=ResultMember)
*ENDWHEN
In this example the REC line can be the same for all 3 loops (%VALUE% can be replaced by direct member reference):
*REC(EXPRESSION=[SomeDim].[Member1]*[SomeDim].[Member2]*[SomeDim].[Member3],SomeDim=ResultMember)
with minimum performance decrease.
Using LOOKUP to the same model to get expression argument member
In some cases for simple formula like multiplication of 2 members (price * qty), but with long list of members, LOOKUP can be used:
Lets assume we have members in dimension SomeDim:
Price1, Price2, Price3, Price4
Qty1, Qty2, Qty3, Qty4
Result have to be written to:
Amount1, Amount2, Amount3, Amount4
Then we can add for dimension SomeDim properties: MULT, RESULT and TYPE and fill it:
ID MULT RESULT TYPE
Price1 Qty1 Amount1 Price
Price2 Qty2 Amount2 Price
Price3 Qty3 Amount3 Price
Price4 Qty4 Amount4 Price
Qty1 Price1 Amount1 Qty
Qty2 Price2 Amount2 Qty
Qty3 Price3 Amount3 Qty
Qty4 Price4 Amount4 Qty
Code will be:
*LOOKUP SameModel
*DIM M:SomeDim=SomeDim.MULT //Get member ID stored in property MULT
*ENDLOOKUP
*FOR %T%=Price,Qty //Or 2 loops - to prevent aggregation.
*WHEN SomeDim.TYPE
*IS %T%
*REC(EXPRESSION=%VALUE%*LOOKUP(M),SomeDim=SomeDim.RESULT)
*ENDWHEN
*NEXT
*FOR/NEXT Loops
In general long and nested *FOR/*NEXT loops have to be avoided due to terrible performance. In most cases instead of *FOR/NEXT loops some property can be created and used in the script code.
Using some value stored as property in calculations
Sometimes it looks as a good idea to store some value in a property and to use it in calculations. Actually it's a bad idea - you can't directly reference the property value in the expression, you have to use some %VAR% and long *FOR/*NEXT loop. Always store values in SIGNEDDATA, may be use some dummy members.
SIGN and ACCTYPE in EXPRESSION calculations
The calculations in default.lgf use different sign conversion logic with ACCTYPE then the script run by DM package. As a result the same script can produce different results as a default.lgf and as a script in DM package.
For default.lgf (BPC NW 10) all values read in the script scope are sign coverted based on ACCTYPE property and the result of EXPRESSION calculation is also sign converted based on ACCTYPE property of the target account:
SignedData_Result = if(Result.ACCTYPE=INC,LEQ, -1, 1) * Function(if(Argument1.ACCTYPE=INC,LEQ, -1, 1) * SignedData_Argument1, if(Argument2.ACCTYPE=INC,LEQ, -1, 1) * SignedData_Argument2, ...)
Example:
Dimension ACCOUNT: Members: A, B, C
ID ACCTYPE
A INC
B EXP
C INC
default.lgf
*WHEN ACCOUNT
*IS A
*REC(EXPRESSION=%VALUE%+[ACCOUNT].[B],ACCOUNT=C)
*ENDWHEN
The data sent by user in the input form will be:
A: 5
B: 10
This data will be stored as SIGNEDDATA:
A: -5
B: 10
Calculations:
(-1 * -5 + 1 * 10) * (-1) = -15 (SignedData_Result)
And on the input form:
C: 15
The same script launched by DM package (BPC NW 10) will not have any sign conversions, all calculations will be done with SGNEDDATA values:
-5 + 10 = 5
The result on the report:
C: -5
*DESTINATION_APP
If it's required to send data to the different model the *DESTINATION_APP statement can be used in default.lgf.
Sign conversion logic is also applicable to writing data using *DESTINATION_APP.
The same rules are applicable to *WHEN/*ENDWHEN loop after the *DESTINATION_APP (by the way, in BPC NW 10 *DESTINATION_APP statement is valid only to the next *WHEN/*ENDWHEN loop, have to be repeated before each *WHEN/*ENDWHEN sending data to other application (in BPC NW 7.5 all *WHEN/*ENDWHEN loops after single *DESTINATION_APP will write to target cube).
If some dimension is missing in the destination model *SKIP_DIM=SomeDim have to be used. But the issue can be in the following case:
SourceModel:
DimMissingInTarget: Member1, Member2, ..., MemberN (base) - having root parent All
SomeDim: Mem1, Mem2, ... - dimension in both Source and Target
TargetModel:
SomeDim: Mem1, Mem2, ... - dimension in both Source and Target
If some of Member1, Member2, ..., MemberN is changed in SourceModel the result of All have to be transferred to TargetModel
The code in default.lgf of SourceModel will be:
//some calculations in the SourceModel
...
*FOR %M%=Member1,Member2,...,MemberN //list of base members of the skipped dimension
*DESTINATION_APP=TargetModel
*SKIP_DIM=DimMissingInTarget
*WHEN DimMissingInTarget
*IS %M%
*WHEN SomeDim //SomeDim - dimension existing both in Source and Target
*IS Mem1,Mem2,... //some list of members of SomeDim changed by user and to be transferred to TargetModel
*REC(EXPRESSION=[DimMissingInTarget].[All]) //Parent All value is used!
*ENDWHEN
*ENDWHEN
*NEXT
N loops for N base members of DimMissingInTarget (useful for small N)
Another option for this particular case is to explicitely scope the scipped dimension with *XDIM_MEMBERSET:
*XDIM_MEMBERSET DimMissingInTarget=<ALL>
*DESTINATION_APP=TargetModel
*SKIP_DIM=DimMissingInTarget
*WHEN SomeDim //SomeDim - dimension existing both in Source and Target
*IS Mem1,Mem2,... //some list of members of SomeDim changed by user and to be transferred to TargetModel
*REC(EXPRESSION=%VALUE%)
*ENDWHEN
But in this case you have to put this code at the end of the default.lgf or restore original scope for DimMissingInTarget:
*XDIM_MEMBERSET DimMissingInTarget=%DimMissingInTarget_SET% // %xxx_SET% variable always contains the original script scope.
Custom Logic BADI in default.lgf
It's also possible to call Custom Logic BADI in default.lgf to perform some calculations that are not easy or even not possible to implement using script logic. The badi have to work with the current scope and can contain some fixed parameters.
Example:
//Some calculations before badi call
...
*START_BADI SOMEBADI
QUERY=ON //to get records from the current scope
WRITE=ON //to use default write to cube
DEBUG=OFF
SOMEPARAM=SOMEFIXEDVALUE
...
*END_BADI // Script scope will be reset to initial script scope here if changed before
//Some calculations after badi call
...
RUNLOGIC_PH BADI
It's also possible to use RUNLOGIC_PH BADI (How To Implement the RUNLOGIC_PH Keyword in SAP... | SCN) to speed up some calculations using CHANGED parameter. For example - single change of price have to recalculate values in multiple entities and multiple time periods.
*START_BADI RUNLOGIC_PH
QUERY=OFF
WRITE=ON
LOGIC = CALLED_LOGIC.LGF
APPSET = SameEnvironment
APP = SameModel
DIMENSION ENTITY=BAS(ALLENTITIES)
DIMENSION SomeDim=%Somedim_SET% //script initial scope
...
CHANGED=ENTITY
Write Back BADI instead of default.lgf
The same functionality can be achieved by Write Back BADI - perform calculations triggered by user input. The details are described here: Calculations in Write Back BADI - Default.lgf R... | SCN
The significant difference between Write Back BADI and default.lgf is that Write Back BADI will receive data sent by user before it's stored in the cube and only sent values will be processed.
B.R. Vadim
P.S. 2014.06.11 - incorrect case about function with "+/-" removed.