I don’t wish to imply that I ‘prefer’ pointers; in fact, I am not using a
single process variable, interprocess variable, or any other ‘vestiges’ of 4D
Classic. I am ‘fully committed’ to object notation. I also use Storage
extensively for system-wide values, and really love it.
The problem I describe is that I need a way to generically ‘get’ and ’set’ the
value of an object (meaning an entry variable on the form).
1) A variable is placed on the form. It’s “variable or expression” is:
Form.LB.Browser_JobForms.en_edit.RigFrom. It has an object name of
“enLSDFromRigDispatch”
I have given it this name because it gives me a simple methodology to SHOW/HIDE
a whole group of objects on the screen with OBJECT SET VISIBLE(*; “enLSD@“;…)
Now I wish to use a standard project method to ‘pretty-format’ this variable.
With ‘4D Classic’ this is easily achieved by making a project method that takes
a POINTER in $1.
The OBJECT SCRIPT would be something simple, like:
PRETTY_FORMAT(Self)
[PRETTY_FORMAT, given Self, would be able to get at the CONTENTS of the
variable and do any formatting options needed]
With ‘4D DOT NOTATION’ …
— How do I create a simple OBJECT SCRIPT that would do something similar to
that in 4D Classic? —
I don’t feel that I should have to resort to using the ‘variable or expression’
name in every single script; because what happens if I change that variable for
some reason and it totally screws up the object script? And it also makes it
very complicated.
THE OBJECT METHOD should be something as simple as:
PRETTY_FORMAT ( Object Get Name ) —— instead of Self
The PRETTY_FORMAT( ) should be able to get at and set the value of the form
object from that name.
Alternatively, if one wants to not bother having scripts for every input
variable that needs PRETTY_FORMAT, they could just do it in the FORM METHOD:
Case of
:( Form event code = on load )
Form.col_toPrettyFormat:= new collection ( Object Name 1, Object Name 2
) … // objects that need to be ‘Pretty Formatted'
: ( Form event code = on losing focus )
$curObjectName:= Form Event.objectName
… see if is in the list of .col_toPrettyFormat …
PRETTY_FORMAT( $curObjectName )
…
So how would one implement something like:
PRETTY FORMAT ( Object Get Name ) in a script; or PRETTY FORMAT (
Form Event.objectName )
???
Thanks,
Chris
p.s. what you describe, Keisuke, is in 4D v18r3; the ability to create classes.
That is very intriguing and a necessary development in 4D, as is C_VARIANT( ).
If one wanted to be able to have the script be:
(Object get name).prettyFormat How would that be achieved?
Even if in the script one could use “This”, but it is null.
I think that ’This’ should be perfectly valid to use in an OBJECT SCRIPT, in a
TRIGGER (referring to the record/entity being operated on), etc. But it is not,
and I have trouble understanding why not.
> On Apr 29, 2020, at 10:14 AM, Keisuke Miyako via 4D_Tech
> <4d_tech@lists.4d.com> wrote:
>
> my feeling is that generic coding is very much possible in object notation,
> but we need to accept that the approach is different.
>
> if you prefer to use pointers such as "Self",
> I think it's best to avoid object notation,
> at least if your goal is to make the code generic.
>
> it's not a defect of object notation,
> but the way to write generic code is different.
>
> if you want to make your code generic in object notation,
> I think you need to fully commit.
>
> what I mean by that, is that you need to think of objects and classes,
> properties and methods.
>
> basically, instead of
>
> doIt(Self)
>
> you would write
>
> $obj.doIt()
>
> where the doIt() formula works on "This".
>
> in my opinion, to take full advantage of object notation,
> it is pretty much mandatory to use
>
> This
> Signal
> Formula
> Form
>
> extensively, as well as
>
> Storage
> New shared object
> New shared collection
>
> strategically.
>
> simply replacing interprocess/process variables with object notation,
> may semantically look like object based coding,
> but at that level you may be losing major advantages of classic code,
> while not gaining much from what the new way of coding has to offer.
>
>> On Apr 29, 2020, at 14:55, Chris Belanger via 4D_Tech <4d_tech@lists.4d.com>
>> wrote:
>> And v18r3 does not even have a solution to this in its documentation.
>
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