fmError: Error class

In Boehringer-Ingelheim/FutureManager: Background Operations in Shiny

Description

Allows to signalize some error in the long function (not enough data to run calculations etc)

Usage

fmError(msg)

Arguments

msg	Message that should be displayed to the user

Value

fmError object

Examples

if (interactive()) {
  library(shiny)
  plan(fmParallelStrategy())
  
  longFun <- function(task, n){
    if (n < 0) return(fmError("n must be >= 0"))
    log(n)
  }
  
  shinyApp(
    ui = basicPage(
      uiOutput("button"), 
      numericInput("n", "n", -3, -5, 5), 
      textOutput("result")
    ),
    server = function(input, output, session){
      fm <- FutureManager$new(input, session)
      output$button <- renderUI(fmRunButton("run", fm))
      Res <- reactiveVal()
      Args <- reactive(list(n = input$n))
      fm$registerRunObserver("run", NULL, Res, longFun, Args, progress = FALSE)
      output$result <- renderText({
        res <- Res()
        fmValidate(res)
        fmGetValue(res)
      })
    }
  )
}

Boehringer-Ingelheim/FutureManager documentation built on June 16, 2021, 6:23 p.m.