[Xotcl] Default-value substitution using substdefault

[Gustaf Neumann]

Dear Maxim,

here the code for the old and new example with expected output.

-g


Original example:

============================================================
   nx::Class create dzs {
     :property {srv:substdefault {[ns_info server]}}
   }
   dzs create o1


   nx::Class create dz -superclass dzs
   dz create o2


   lappend _ [o1 cget -srv] [o2 cget -srv]
   # returns a list containing the name of the current server twice
============================================================

New example

============================================================
   nx::Class create D
   nx::Class create FOO {
     :property {d:object,type=::D,substdefault {[::D new]}}
     :create o3
   }
   set o [o3 cget -d]

   $o info class
   # returns ::D
============================================================


On 12.08.22 20:40, Maksym Zinchenko wrote:
> Dear Gustaf, sorry I've tried to remove the comma but it breaks the 
> code completely.
> And I can't see minimal example also. I based my code on an example in 
> the next-scripting tutorial (3.7.6. Defaults substitution):
>
> :property  {d:object,type=::D,substdefault {[::Dnew]}}
>
>
>
> On Fri, Aug 12, 2022 at 4:00 PM Gustaf Neumann <neumann at wu.ac.at> wrote:
>
>     Dear Maxsym,
>
>     the comma after the variable name "srv" was not correct.
>     We should provide an error message for that....
>
>     See below for a minimal example showing the correct behavior.
>
>     all the best
>
>     -gustaf
>
>     On 12.08.22 16:25, Maksym Zinchenko wrote:
>     > Hello, I'm having trouble to define "srv" property in my
>     superclass with
>     > default value from Naviserver command, may be Im doing smth
>     wrong, would be
>     > so kind to help:
>     >
>     > nx::Class create dz_superclass {
>     >> :property identifier
>     >> :property {srv,substdefault=0b111: {[ns_info server]}}
>     >> :method init {} {
>     >> set :uuid ""
>     >> if {[[current object] info vars identifier] eq ""} {
>     >> set :identifier ""
>     >> } else {
>     >> if {[is_uuid ${:identifier}] == 1} {
>     >> set :uuid ${:identifier}
>     >> }
>     >> }
>     >> }
>     >> }
>     > nx::Class create dz_class -superclass dz_superclass {
>     >> :method init {} {
>     >> if {${:identifier} ne ""} {
>     >> set :obj_data [dict getnull [select_all client *
>     >> uuid_client=\'${:identifier}\'] 0]
>     >> }
>     >> }
>     >> }
>     >>
>     > When I create object:
>     >
>     >> dz_class create o1 -identifier 67720c6d-d00f-479b-85cf-4edaa5a9cb1a
>     >>
>     > o1 cget -srv
>     > Im getting literal "[ns_info server]" instead of my virtual
>     server name
>     >
>     >
>     >> [ns_info server]
>     >>
>     > Thank you
>