Jeremy, as I am sure you know pointers in 4D have some 'quirks'. I suspect that you have found another.
Chip On Tue, 26 Feb 2019 07:18:36 +0000, Jeremy Roussak via 4D_Tech wrote: > Kirk, > > My apologies. I mistyped the offending lines! > > The lines causing the error dereference the pointers. So they are > > $to.toDate->:=$from.toDate-> > $to.toAge->:=$from.toAge-> > etc. > > The curious things are that (a) the dereferenced pointers do > definitely point at variables of the same type; (b) although I get an > alert with the error message, the assignment does in fact work (that > is, if I click “continue”, everything is exactly as it should be > when the method completes). > > I can get round the error by using pointer variables: > > $pTo:=$to.toDate > $pFrom:=$from.toDate > $pTo->:=$pFrom-> > > which works fine. I just don’t understand the actual error message, > since I’m not doing what it’s accusing me of doing. > > Jeremy > > > >> On 25 Feb 2019, at 16:47, Kirk Brooks via 4D_Tech >> <4d_tech@lists.4d.com> wrote: >> >> Jeremy, >> Since you are writing the data to an object what's the value of using the >> pointer? Why not just write the data? >> >> In fact, since TCMGetRow looks like it is simply holding the data for the >> transfer you could make it a loop: >> >> For($i;1;number of objects) >> >> $o["_"+string($i)]:=Object get pointer(Object named;$root+string($i))-> >> >> End for >> >> This way you don't need to care about the data type assuming the 2 objects >> actually have the same typed objects for each index. >> >> But to specifically answer your question I would take a look at the way the >> date value is stored in your object and then how you reference it. There's >> another post about dates and objects that sounds on point with what you are >> doing. >> >> >> On Mon, Feb 25, 2019 at 7:37 AM Jeremy Roussak via 4D_Tech < >> 4d_tech@lists.4d.com> wrote: >> >>> I have a form which shows a variable number of rows of numbers and text. >>> The rows are created using OBJECT DUPLICATE on each of the >>> half-dozen items >>> in the row (yes, using a collection listbox might be a better way >>> do to it, >>> but I wrote this code a while ago). If a row is deleted, I need to >>> copy the >>> contents of the rows beneath it upwards. >>> >>> >>> So I have a method which creates an object and populates it with pointers >>> to the created variables. I call this to get a set of pointers to one row, >>> then again to get a set to the next row, and then I copy. >>> >>> I start >>> >>> C_OBJECT($from;$to) >>> $from:=TCMGetRow($start) >>> >>> then in a loop, >>> >>> $to:=$from >>> $from:=TCMGetRow($i) >>> >>> $to.toDate:=$from.toDate >>> $to.toAge:=$from.toAge >>> etc. >>> >>> >>> >>> TCMGetRow has >>> >>> C_OBJECT($0;$o) >>> C_LONGINT($1;$row) >>> $row:=$1 >>> >>> C_TEXT($root) >>> >>> $root:="vr"+String($row)+"c" >>> $o:=New object >>> >>> $o.toDate:=OBJECT Get pointer(Object named;$root+"0") >>> $o.toAge:=OBJECT Get pointer(Object named;$root+"1") >>> etc >>> >>> $0:=$o >>> >>> I’m getting the message in the subject line in the main loop for each >>> assignment, but only when compiled; interpreted, it works fine. In the >>> debugger, the pointers in $to and $from point to variables of the >>> same type. >>> >>> I’m quite new to extensive use of objects. What am I missing? >>> >>> Jeremy >>> >>> ********************************************************************** >>> 4D Internet Users Group (4D iNUG) >>> Archive: http://lists.4d.com/archives.html >>> Options: https://lists.4d.com/mailman/options/4d_tech >>> Unsub: mailto:4d_tech-unsubscr...@lists.4d.com >>> ********************************************************************** >> >> >> >> -- >> Kirk Brooks >> San Francisco, CA >> ======================= >> >> What can be said, can be said clearly, >> and what you can’t say, you should shut up about >> >> *Wittgenstein and the Computer * >> ********************************************************************** >> 4D Internet Users Group (4D iNUG) >> Archive: http://lists.4d.com/archives.html >> Options: https://lists.4d.com/mailman/options/4d_tech >> Unsub: mailto:4d_tech-unsubscr...@lists.4d.com >> ********************************************************************** > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > Archive: http://lists.4d.com/archives.html > Options: https://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:4d_tech-unsubscr...@lists.4d.com > ********************************************************************** --------------- Gas is for washing parts Alcohol is for drinkin' Nitromethane is for racing ********************************************************************** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **********************************************************************
