Actually, I see that 4D’s widgets do not work either (dateEntry) when the bound variable is Form.thisDate.
I know that 4D cannot make Pointers to Form. elements like that. But it is pretty bad that there is no way (apparently) for a subform to access its bound variable in this instance. anyone confirm that? — Chris > On Jul 7, 2019, at 6:34 PM, Chris Belanger <[email protected]> wrote: > > On parent form WIDGET_TESTER I have a subform of instance name > ‘formDate’. The name of the subform is “DateEntry”. > I wish to have a BOUND VARIABLE of type DATE on this instance. > > if the DATE is a process variable, it works swell. > **** if it is based on the parent form’s FORM. (such as Form.thisDate) > this does not work. ***** — MY CONUNDRUM! > > in particular: > In the Subform’s form method, in the ‘On Bound Variable Change’ handler, the > subform needs to get the bound variable’s pointer. > This is done either with OBJECT Get Pointer(Object subform container) > or (as in 4D’s widget collection source code) Self(Object subform > container) is used. > > This is successful if the bound variable is a process variable. It does not > work if it is Form.thisDate (which is a date; set to ‘current date’ for > example). > > The Form.thisDate is defined in the parent’s ON LOAD handler, so it should > exist by the time the instance ‘formDate’ is configured. Sure seems to work > for process variables! > > I am not yet an expert on subform creation, as I have mostly avoided them in > the past. > However, I can see the wisdom of creating widgets to put in my own object > library. > But they need to be able to work in the context of a parent’s Form. object to > be of use for me, as I use this extensively rather than process variables. > > thanks for any suggestions, > Chris Belanger > > —————— > > Detailed explanation (if needed or interested) > > > I’ve been working on making some widgets, inspired by 4D’s collection. My > question is about rewriting the DateEntry widget. After I do that, I intend > to do some other widgets. > > When I looked at the 4D source code, I saw it still uses a lot of code, > methods, process vars, etc. > So I made a ‘DateEntry’ widget (in my custom component) that employs Form. > objects / variables instead. It works very nicely, with a great > simplification of code and elimination of process methods and process vars. > > When the widget is put (as a subform) on a Parent Form, the Bound Variable is > of type DATE. > It works as expected whenever it is a PROCESS VARIABLE. > > However, if the bound variable is Form.theDate (a DATE ‘variable’), then > it fails. > > > WHAT I AM DOING: > In the widget’s form: > In the FORM EVENT ‘On Bound Variable Change’ — I configure what I need for > the widget to process the bound variable. This involves creating some Form. > vars to manage the input. > • so in this situation, it is very simple. > > Case of > :(Form event = On Bound Variable Change) // use the value of the Bound > Variable (a Date) to configure the components DAY, MONTH, YEAR > > $theVarPtr:=OBJECT Get Pointer (Object subform container) // this is the > pointer to the bound variable, for instance ->processVar > Form.theDate := $theVarPtr-> // copy the contents of the subform contain to > our widget’s ‘date’ so we can manipulate it without changing the bound > variable until we are ready (On Deactivate) > // Break it into its component pieces: DAY, MONTH, YEAR, for the widget > Form.theDay := Day of(Form.theDate) > Form.theMonth:= Month of(Form.theDate) > Form.theYear:=Year of(Form.theDate) > > > —— > > OBJECT Get Pointer ( Object subform container) works as expected when the > Parent Form’s bound variable is of type DATE and is a process Variable. > > Self(Object subform container) also gets the Parent Form’s bound variable > (this is what the 4D widget uses; however, Self is always Nil in this > situation) > > ** however ** > it does not work when the bound variable is a Date that is define in the > Parent’s Form. context. I.E. if the bound variable is Form.simpleDate > this does not work. > If it is Form.entity.simpleDate this also does not work. > > ********************************************************************** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
