> You can see you could not simply change the name of > the object type as the > properties of each object are not the same and would > have been more trouble to > change the code in the parser to make it happen than > the trouble to simply > change to the other type button (if you desire it) > in the designer.
In this particular case, where properties were added but none removed and no names changed, the DFM loader would, in fact, be able to correctly load the speed button component, even if it had new properties associated with it. No changes to the loading mechanism would be necessary. I believe that some other controls have actually had properties added to them without requiring a duplication of the control class. That said, I think these two buttons are sufficiently different that it does make sense to leave the old one in place while adding the new one. And there is one case where it is critical to have them both -- if you are developing code on a new version that, for some reason, might need to run on an older version of R:Base. If you were to try to load a form with a control that did _not_ declare some of the properties found in the DFM then you would certainly experience problems. Perhaps the old button could be moved to the Legacy Controls tab when a new version is made available? -- Larry
