R/server.R

In monitOS: Monitoring Overall Survival in Pivotal Trials in Indolent Cancers

#' Shiny app server
#'
#' @param input generic shiny var
#' @param output generic shiny var
#' @param session generic shiny var
# nocov start
app_server <- function(input, output, session) {
  wrap <-
    function(X, decimal = 3) {
      return(paste(round(X, decimal), collapse = ","))
    }
  unwrap <-
    function(X) {
      return(as.numeric(unlist(strsplit(
        gsub(" ", "", X), ","
      ))))
    }

  # Core reactive function - OCs plots & results
  react <- reactive({
    # Parse as vectors

    events <- c(unwrap(input$eventPA), input$eventOS)
    updateTextInput(session, "events", value = wrap(events))

    # boundaries
    boundaries <- bounds(
      events = events,
      power_int = input$power_int,
      falsepos = input$falsepos,
      hr_null = input$hr_null,
      hr_alt = input$hr_alt,
      rand_ratio = input$rand_ratio,
      hr_marg_benefit = input$hr_marg_benefit
    )


    hr_pos <- exp(boundaries$lhr_pos)
    updateTextInput(session, "hr_pos", value = wrap(hr_pos))


    # Update column names
    # columns <- c(
    #   'Deaths',
    #   'OS HR threshold for positivity',
    #   'One-sided false positive error rate',
    #   'Level of 2-sided CI needed to rule out delta null',
    #   'Probability of meeting positivity threshold under delta alt',
    #   'Posterior probability the true OS HR exceeds delta null given the data',
    #   'Predictive probability the OS HR estimate at Final Analysis does not exceed the positivity threshold',
    #   'Probability of meeting positivity threshold under incremental test benefit'
    # ) # Optional
    # names(boundaries$summary) <- columns

    return(boundaries)
  })

  # Rendering
  output$bounds <- renderTable(react()$summary[, -c(6, 7)])
}
# nocov end