How to have gridLayoutHeaderCell in gridlayout ? How to create columns dynamically in a grid ?

Hi,

Using a flatten() function will help you in this case:

 headerCells: {
      a!flatten(
        a!forEach(
          items: { "230108", "230109", "230110" },
          expression: {
            a!localVariables(
              local!list: fv!item,
              a!gridLayoutHeaderCell(label: local!list)
            )
          }
        )
      )
    }

Avoid the {} in your a!forEach expression parameter.   you are doing a "a!forEach(items:{1,2,3}, expression:{...})
just do a  "a!forEach(items:{1,2,3}, expression:...)  then it should be fine.

a!gridLayout(
    label:"program",
    headerCells: {
        a!forEach(
            items: {"230108","230109","230110"},
            expression:  a!localVariables(
                    local!list: rule!GPO_questionDetails(questionID: fv!item),
                    a!gridLayoutHeaderCell(label: local!list.label)
            )
            
        ),
        if(
            not(rule!APN_isTrue(ri!isReadOnly)),
            a!gridLayoutHeaderCell(label: ""),
            {}
        )
    }
),