ui1<-fluidrow(...)
   ui2<-fluidrow(...)

shinyUI <- function(ui) {

  fluidPage(
    conditionalPanel(
      condition = "output.logged=='TRUE'",
      ui2),
    conditionalPanel(
      condition = "!output.logged",
  ui1)
  )
}

output$logged<- reactive({
    print(value)
    value
      })
  outputOptions(output, "logged", suspendWhenHidden = FALSE)