r - Automating Interaction with RShiny App -

i trying automate interaction of shiny app displays series of results while incrementing through predetermined range of inputs, without having repetitiously count , change input values. automation provide systematic view of set of inputs, such displays of refreshed price charts selected stocks, or plots of current performance indicators real-time processes being monitored.

this similar question [update graph/plot fixed interval of time] (update graph/plot fixed interval of time) runs loop timer. extending approach, objective to: a) automatically set invalidatelater pause high (1 hour) stop cycle after fixed (5) set of displays, pending new user input restart it.

b) [when can that, add counter-based control cycle through set of input$obs before stops. simplicity, step, has same error , presumably same solution, omitted here.]

using above referenced toy example, following script repeatedly cycle through 5 displays, yields error rather changing pause interval.

listening on port 8100 error in hist.default(dist, main = paste("last histogram count =", as.numeric(updater()), : 'x' must numeric

as.numeric(autocontrol()) error: not find function "autocontrol"

i can not find reactive conductor, reactivevalues or other methods task requires. thank help.

library(shiny)  updates <- 0 updater <- function(){ updates + 1 }  runapp(list(   ui = pagewithsidebar(        headerpanel("hello shiny!"),    sidebarpanel(     sliderinput("obs",        "number of observations:",        min = 1,       max = 1000,        value = 50)     ,      selectinput(inputid = "secpause",         label = "seconds between displays:",         choices = c(1, 2, 3, 60*60),         selected = 2)   ),    mainpanel(     plotoutput("distplot")   ) ),    server =function(input, output, session) {         updatetracker <- reactive( {              invalidatelater(as.numeric(input$secpause) * 1000, session)             updates <<- as.numeric(updater())         })          autocontrol <- reactive( {             if(updatetracker() <= 5)             secpause <<- input$secpause                     else                     secpause <<- 60*60             return(secpause)         })      output$distplot <- renderplot( {         if(updatetracker() <= 5) {         # generate rnorm distribution , plot         dist <- rnorm(input$obs)         hist(dist, main = paste("histogram count =" , updatetracker()))         }         else {             updates <<- 0             hist(dist, main = paste("last histogram count =",                as.numeric(updater()), "with secpause =",                as.numeric(autocontrol())))                 }     })     } )) 

you getting error because hist distribution defined inside if clause, using (after 5 intervals) inside else clause, not defined. that's why works first 5 intervals.

   if(updatetracker() <= 5) {         # generate rnorm distribution , plot         dist <- rnorm(input$obs)         hist(dist, main = paste("histogram count =" , updatetracker()))         }         else {             updates <<- 0             hist(dist, main = paste("last histogram count =",                as.numeric(updater()), "with secpause =",                as.numeric(autocontrol())))                 } 

after moved dist before if condition, got cycling work. (i split code ui.r , server.r make more manageable.) not pasting here since same code, can find working version of code in gist.