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Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 1:56 pm
by robert
Kees,
The strange syntax in VO is for indexed assigns.
What is SELF:PKey in this context?
Robert
Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 2:08 pm
by Kees Bouw
Robert,
Is it an array, defined like this:
Kees.
Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 2:14 pm
by robert
Kees,
I think that the code should be changed to:
SELF:PKey[nAUT] := #AUTNO
Most likely this was a bug in VO.
Robert
Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 2:15 pm
by Kees Bouw
Robert,
Well, you mentioned "assign" and I looked for it and indeed it is (also) an assign:
Code: Select all
ASSIGN PKey(KeyVal, NameSym) CLASS _BPDataDialog
LOCAL i AS DWORD
IF Empty(SELF:FPKey)
SELF:FPKey := {{NameSym, KeyVal}}
ELSE
i := AScan(SELF:FPKey, {|aSub| aSub[1] = NameSym})
IF i = 0
AAdd(SELF:FPKey, {NameSym, KeyVal})
ELSE
SELF:FPKey[i,2] := KeyVal
ENDIF
ENDIF
RETURN KeyVal
I never heard of "indexed assigns". Is there an explanation somewhere that I can study?
Kees.
Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 2:19 pm
by robert
Kees,
You cannot have an EXPORT and ASSIGN with the same name.
If you rename the EXPORT then the syntax created by the Exporter should work.
Robert
Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 4:35 pm
by Chris
Hi Kees,
About indexed assigns or accesses:
Normally you have a regular ACCESS like that:
ACCESS MovieLength AS INT
that you can call with
nLength := oMovie:MovieLength
but it is also possible to have an access with an index part as a parameter ("nMoviePart" below), which can be used to supply more information to the ACCESS, to return different values based on it:
ACCESS MovieLength( nMoviePart AS INT ) AS INT
This is called an "indexed" property, that you can call with this X# syntax:
nLength := oMovie:MovieLength[2] // get length of 2nd part
Similarly for ASSIGNs, for declaring regular ones you just need to supply a single parameter that holds the new value:
ASSIGN MovieLength(nNewLength AS INT)
...
SELF:MovieLength := 100
and for indexed properties you need to supply also the "index":
ASSIGN MovieLength(nNewLength AS INT, nMoviePart AS INT)
and those can be called like that in X# syntax:
SELF:MovieLength[2] := 100 // set the length of part 2 to 100
Unfortunately, instead of this easy to read and use syntax for calling indexed assigns, VO uses this bizarre one:
SELF:[MovieLength , 2] := 100
Just because this is so strange, instead of this syntax, in X# we went for the more "normal" one above.
Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 7:56 pm
by Kees Bouw
robert wrote: ↑Fri Apr 19, 2024 2:19 pm
Kees,
You cannot have an EXPORT and ASSIGN with the same name.
If you rename the EXPORT then the syntax created by the Exporter should work.
Robert
I have renamed the export, and the syntax SELF:PKey[#AUTNO] seems to work. But, many times the class is inherited by another class and then the syntax is SELF:Owner:PKey[#AUTNO], where Owner is a USUAL. On those lines, I still get error XS9059 "Cannot convert Array Index from 'symbol' to 'int'".
Could it be that when the indexed access/assign is via a USUAL like Owner, you can't use Symbols?
Kees.
Re: Miscellaneous questions about converting VO code to X#
Posted: Fri Apr 19, 2024 9:02 pm
by Chris
Hi Kees,
Yes, calling indexed properties is not supported (yet, at least) through late bound calls. You will ned to use an intermediate typed variable for that, like:
LOCAL oOwner AS ClassNameOfOwner
oOwner := (ClassNameOfOwner) SELF:Owner
oOwner:PKey[#AUTNO] := ...
where you will need to replace "ClassNameOfOwner" with the actual class name of course.
Re: Miscellaneous questions about converting VO code to X#
Posted: Mon Apr 22, 2024 8:21 am
by Kees Bouw
Chris,
Thank you for the explanation and also for the previous explanation! The problem exists in at least 137 locations (if I import more code, the number will go up) in the application so it will be a lot of work to modify them all to the workaround but I guess there is no other way...
Kees.
Re: Miscellaneous questions about converting VO code to X#
Posted: Mon Apr 22, 2024 8:44 am
by Chris
Hi Kees,
If it helps, it can also be done without an intermediate variable, but in a single line, it's just less readable:
( (ClassNameOfOwner) SELF:Owner):PKey[#AUTNO] := ...
You will still need to supply the class name, but if it's the same in most cases, then a global search & replace might make things much easier..