[Mondrian] Cognos 8.3 & "VBA!" Functions

[Julian Hyde]

This is fixed in the just-released mondrian-3.0.3.

Julian 

> -----Original Message-----
> From: mondrian-bounces at pentaho.org 
> [mailto:mondrian-bounces at pentaho.org] On Behalf Of 
> timothy.lambert at thomsonreuters.com
> Sent: Wednesday, April 23, 2008 6:24 PM
> To: mondrian at pentaho.org
> Subject: RE: [Mondrian] Cognos 8.3 & "VBA!" Functions
> 
> The way I understood the problem was that VBA!FOO was an 
> alias for FOO.  Not that VBA was a package name qualification 
> of the function.
> 
> Looking at things as a package name qualifier issue 
> completely changes things - I retract everything I said in my 
> original email. :)
> 
> Since I didn't realize that VBA is a package name and the ! 
> is a separator, I also don't know whether or not they can be 
> multi-leveled.  But I'll try to find out and open the bug.
> 
> Thanks.
> 
> 
> -----Original Message-----
> From: mondrian-bounces at pentaho.org on behalf of Julian Hyde
> Sent: Wed 4/23/2008 8:07 PM
> To: 'Mondrian developer mailing list'
> Subject: RE: [Mondrian] Cognos 8.3 & "VBA!" Functions
>  
> For tracking purposes, can you please log a bug for this.
> 
> How general does MDX syntax allow package names to be? Does it allow
> multiple levels of qualification (e.g. 'Foo!Bar!MyFun()')? 
> Does it allow
> spaces (e.g. 'VBA ! Len("foo")).
> 
> We should change the scanner to handle the most general case. 
> I think that
> will mean that a function is a list of names rather than the 
> current single
> name. Then FunTable.getDef() will become
> 
>     public FunDef getDef(
>         Exp[] args,
>         Validator validator,
>         List<String> funNames,
>         Syntax syntax)
> 
> Initially we can change getDef to ignore all but the last 
> member of the name
> list, that is, assume that functions are globally unique.
> 
> Julian
> 
>  
> 
> > -----Original Message-----
> > From: mondrian-bounces at pentaho.org 
> > [mailto:mondrian-bounces at pentaho.org] On Behalf Of 
> > timothy.lambert at thomsonreuters.com
> > Sent: Wednesday, April 23, 2008 3:33 PM
> > To: mondrian at pentaho.org
> > Subject: [Mondrian] Cognos 8.3 & "VBA!" Functions
> > 
> > Cognos 8.3 generates MDX VBA functions prefixed with "VBA!"; 
> > e.g. VBA!LEN(<string>).  The signatures and semantics of the 
> > functions are the same.
> > 
> > I've investigated a number of ways to enhance Mondrian to 
> > support this prefix.  
> > 
> > With all these following solutions, the Mondrian lexical 
> > analyzer needs to be enhanced to support an identifier token 
> > that contains a '!'.  This is trivial since the grammar does 
> > not specify the use of '!'.  Specifically, at line 640 in 
> > Scanner.java#21, add " case '!':
> > 
> > After this is done, one of the following can be done...
> > 
> > 1) At the scanner level strip "VBA!" from identifiers.
> > 
> > 2) When functions are being resolved during parser reduction 
> > action processing, strip "VBA!" from the function name 
> being resolved.
> > 
> > 3) Some variation of 1 or 2 in which an alias map is used 
> > instead of just handling "VBA!".
> >  
> > 4) In the Vba class, make a new method for each VBA! alias.  
> > Each new method would delegate to its non-VBA! counterpart.
> > 
> > 5) Enhance FunDef and Resolver to support the notion of aliases.
> > 
> > ----
> > 
> > While 1 and 2 are really quick to implement, I view them as 
> > hacks.  Hacks because they are disjoint from the code that 
> > sets up function definitions, and does not fit well within 
> > the OO design of the rest of the system.
> >  
> > I view 3 as only slightly better.  Depending on how the map 
> > is constructed it may have the same design flaw as 1 and 2.
> > 
> > The forth option is also easy and pretty clean.  The only 
> > problem is that it only handles the VBA! problem.  Other 
> > functions are setup differently and would require a different 
> > (albeit similar) approach.  Furthermore it's very verbose.
> >  
> > I would like to promote some variation of 5.  The question is 
> > how to best incorporate general alias information into the 
> > rest of the processing.
> > 
> > One idea that I was playing with is to create a Resolver 
> > decorator/wrapper that exposes the aliased name but delegates 
> > to the same Resolver instance setup for the "normally" named FunDef.
> > 
> > There would be a bit of code that processes the aliases and 
> > adds Resolver instances to the map that is part of FunTableImpl.
> > 
> > Once that map is setup, the rest of the code should operate as is.
> > 
> > Feedback appreciated.
> > 
> > - Tim
> > 
> > 
> > 
> > 
> > _______________________________________________
> > Mondrian mailing list
> > Mondrian at pentaho.org
> > http://lists.pentaho.org/mailman/listinfo/mondrian
> > 
> 
> 
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