Thank you Hans and Wolfgang for the explanation!

Adam

On Tue, Oct 12, 2021 at 4:22 PM Wolfgang Schuster <wolfgang.schuster.lists@gmail.com> wrote:
Hans Hagen via ntg-context schrieb am 12.10.2021 um 14:12:
> On 10/11/2021 1:38 PM, Adam Reviczky via ntg-context wrote:
>> Hi,
>>
>> I am trying to use a combination figure with luacode (both with
>> latest MKIV and LMTX).
>> However, the figures do not line up in the grid of the combination.
>>
>> I get the correct result with examples 1 and 2 below, but example 3
>> using lua functions for combination and externalfigure is what I
>> wanted to use in the first place.
>>
>> MWE:
>>
>> \starttext
>>
>> \startluacode
>>
>> -- Combination 1
>> context.startplacefigure({title = "Figure"})
>> context.startcombination({nx = "2", ny = "2"},
>>
>> "\\externalfigure[cow][width=50mm]","Caption 1",
>> "\\externalfigure[cow][width=50mm]","Caption 2",
>> "\\externalfigure[cow][width=50mm]","Caption 3",
>> "\\externalfigure[cow][width=50mm]","Caption 4"
>> )
>>
>> context.stopcombination()
>> context.stopplacefigure()
>>
>> -- Combination 2
>>
>> context.startplacefigure({title = "Figure"})
>> context.startcombination({nx = "2", ny = "2"},
>>
>> "Picture 1","Caption 1",
>> "Picture 2","Caption 2",
>> "Picture 3","Caption 3",
>> "Picture 4","Caption 4"
>> )
>>
>> context.stopcombination()
>> context.stopplacefigure()
>>
>> -- Combination 3
>>
>> context.startplacefigure({title = "Figure"})
>> context.startcombination({nx = "2", ny = "2"},
>>
>> context.externalfigure({"cow"},{width = "50mm"}),"Caption 1",
>> context.externalfigure({"cow"},{width = "50mm"}),"Caption 2",
>> context.externalfigure({"cow"},{width = "50mm"}),"Caption 3",
>> context.externalfigure({"cow"},{width = "50mm"}),"Caption 4"
>> )
>>
>> context.stopcombination()
>> context.stopplacefigure()
>>
>> \stopluacode
>> \stoptext
>>
>> Any hints on what I am doing wrong in example 3?
> as in any prodedural language a function as argument gets immediately
> executed so you need to delay:
>
> context.startplacefigure({title = "Figure"})
>     context.startcombination({nx = "2", ny = "2"},
>         context.delayed.externalfigure({"cow"},{width = "50mm"}),
> "Caption 1",
>         context.delayed.externalfigure({"cow"},{width = "50mm"}),
> "Caption 2",
>         context.delayed.externalfigure({"cow"},{width = "50mm"}),
> "Caption 3",
>         context.delayed.externalfigure({"cow"},{width = "50mm"}),
> "Caption 4"
>     )
>     context.stopcombination()
> context.stopplacefigure()
>
> (this is why encoding complex documents completely in a scrtipt
> language is non trivial and why for instance these template systems
> are there because these accumulate)

Another solution is to use the content and caption blocks for each
combination entry.

\starttext

\startluacode

context.startplacefigure({title = "Figure"})
     context.startcombination({nx = 1, ny = 1})
         context.startcontent()
             context.externalfigure({"cow"},{width = "50mm"})
         context.stopcontent()
         context.startcaption()
             context("Caption 1")
         context.stopcaption()
     context.stopcombination()
context.stopplacefigure()

\stopluacode

\stoptext

Wolfgang