document function is working to get size and extenstion

HI team,

i want to find the type of extension and Size of list of documents and i have used document function and build an expression rule it is working fine in expression rule as expected when i call that expression in an interfcae  it is shoowing error as document function is deleted. 

a!localVariables(
  local!size: a!forEach(ri!documents, document(fv!item, "size")),
  local!extension: a!forEach(
    ri!documents,
    document(fv!item, "extension")
  ),
  toboolean(
    and(and(reject(
      fn!isnull,
      {
        a!forEach(
          local!extension,
          if(fv!item <> "pdf", false, null)
        )
      }
    )),
    and(reject(
      fn!isnull,
      {
        a!forEach(
          local!size,
          if(fv!item > 5000000, false, null)
        )
      }
    )
    )))
  
)

when i use in interface getting error as shown below