I humbly suggest that this is needed, but furthermore the following use case be considered.
XML ------> HSSF -----------> XLS | | | XSL | | | XHTML In this case we are outputting to XLS for one edition of our spreadsheet and XHTML for another (or PDF, or whatever). XHTML does not support formulas, and lets say we want to output the result. I think our calculation engine should support this scenario as I think it will be a common one. Regardless, I totally think we need one. -Andy Avik Sengupta wrote: >>I'd like to use poi in the following scenario: >> >> >That is certainly a very common requirement. In the past, we have either used >VJ+ - COM integration (if you are on windows) or JIntegra Bridge successfully >for such scenarios. > > > >>But this does not seem very adequate in >>server environments. >> >> >Yeah, but if you want to use excel as your calculation engine, you take what >you get :) > >As Andy mentioned, having hooks into excel from poi is certainly not a good >idea. > > > >>But what would be really >>helpful is a hook where a calculator could be installed >> >> > >If there is an open source java calculator available .. or somone is willing to >write one .. , we could certainly look at integrating with it. I would >certainly be willing to help in writing any such hooks. However, I dont think a >generic interface to ANY calculator will work, without knowing what/how such a >calculator does/works. > >Regards >- >Avik > > > >Quoting Werner Froidevaux <[EMAIL PROTECTED]>: > > > >>Avik, >> >> >> >>>files, and not a functional replacement for Excel/Word etc. >>> >>> >>I'd like to use poi in the following scenario: >> >>- The user creates sheets with formulas, etc. he/she can >> test them all within excel. >>- tested sheets are then deployed into a running >> (java) application. >>- The application (e.g. EJB) is using the sheets as >> calculator. When invoked it can set predefined fields in >> the sheet, do a recalc() and return the results to >> the calling client application. >> >>This way the user does not have to write java programs for >>specifying calculations. >> >>An alternative scenario would be to call Excel through >>OLE automation. But this does not seem very adequate in >>server environments. >> >> >> >>>We depend on Excel >>>automatically recalculating the sheet on open. >>> >>> >>Not very useful in the scenario described above (or >>users do manually a recalc on every EJB invocation). >> >> >> >>>I dont know if it should be any other way. do we want to have >>>an implementation >>>of MMULT for example in poi? >>> >>> >>Not really ;-) See your point. But what would be really >>helpful is a hook where a calculator could be installed >>(for example a setCalculator() on the workbook). A >>recalc() method on the workbook could walk the cells >>(don't know excactly the strategy of excel), manage >>a calculation stack, call the calculator and assign the >>calculated values to the cells. >> >>-werner. >> >> >> >>>-----Original Message----- >>>From: Avik Sengupta [mailto:[EMAIL PROTECTED]] >>>Sent: Montag, 27. Mai 2002 13:33 >>>To: POI Developers List; [EMAIL PROTECTED] >>>Subject: Re: recalc for sheets >>> >>> >>>Werner, >>> >>>Thanks for your patches. >>> >>>Abt recalc .. actually, poi does not have any "calc" >>>functionality as yet. The >>>idea (at least mine :) is that poi is an api for reading and >>>writing Excel/OLE2 >>>files, and not a functional replacement for Excel/Word etc. >>> >>>As per this philosophy, poi at the moment just writes the >>>formulas in a string >>>as per the excel format, but does not actually calculate the >>>result value of >>>the formula. the cell value record is set to 0 (of course, >>>we need to change >>>that for string formulas .. but thats another story). We >>>depend on Excel >>>automatically recalculating the sheet on open. (This happens >>>on office 2000+, >>>there is a record we can set to ensure it happens on 97 as well. ) >>> >>>I dont know if it should be any other way. do we want to have >>>an implementation >>>of MMULT for example in poi? >>> >>>That having been said, if you have a better idea, please, fire away. >>> >>>Regards >>>- >>>Avik >>> >>> >>>Quoting Werner Froidevaux <[EMAIL PROTECTED]>: >>> >>> >>> >>>>Is there a way to recalc() a sheet? I've found some >>>>hints in the FormulaRecord class but I'm not sure >>>>whether this is the right place to look at. >>>> >>>>If there is no recalc() function yet, where is the >>>>right place to add it. >>>> >>>>-werner. >>>> >>>> >>>>-- >>>>To unsubscribe, e-mail: >>>> >>>> >>><mailto:poi-dev-> [EMAIL PROTECTED]> >>> >>> >>>>For >>>> >>>> >>>additional commands, >>>e-mail: >>> >>> >>>><mailto:[EMAIL PROTECTED]> >>>> >>>> >>>> >>>> >>> >>> >>-- >>To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> >>For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> >> >> >> >> > > > >-- >To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> >For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > > > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
