Want to disable button conditionally on addRowlink: a!dynamicLink

Hi All,

I want to disable button if data set contains one row already . I want to restrict to add more then one. If it is more than one then Add button should not allow me to add new row.

Please help me on that.

addRowlink: a!dynamicLink(
label: "Sample",
value: 'type!{****'(***,***,***),
saveInto: {a!save(***,append(***))}
),

validations: if(
toInteger(
count(
ri!aData
)
) > "1",
FormAPI.setDisabled("???", ??),
""
)

Regards

Saurav