Shiny promises future is not working on eventReactive












0















I have an inputButton than when you click it, 2 querys to mysql database are done. One is a heavy one (more than 10 secs) and the other is light (less than 0.01sec to get data).



As I want to show the result of this querys on shiny app, I have intendeed to use Promises and Future packages for asyncronous loading.



In the example that I show you of my code, I have simulated the SQL querys with the function heavyFunction, which is intended to simulate the heavy query and the ligth one time loads.



The issue is that this code is not working for me, because the results of the light query are not shown till the heavy query is done.



Note: In the Rstudio console, this code works perfect...



library(future)
library(promises)
plan(multiprocess)

heavyFunction <- function(n){
Sys.sleep(n)
print(n)
}


ui <- fluidPage(
actionButton("go","Show the data"),
textOutput("result0sec"),
textOutput("result10sec")

)

server <- function(input,output,session){


data0 <- eventReactive(input$go,{
heavyFunction(0)


})

data10 <- eventReactive(input$go,{
heavyFunction(10)


})
output$result0sec <- renderText({
data <- data0()
future(data)%...>%print()
})


output$result10sec <- renderText({
data <- data10()
print(data)
})




}
shinyApp(ui,server)


What I'm doing wrong?










share|improve this question



























    0















    I have an inputButton than when you click it, 2 querys to mysql database are done. One is a heavy one (more than 10 secs) and the other is light (less than 0.01sec to get data).



    As I want to show the result of this querys on shiny app, I have intendeed to use Promises and Future packages for asyncronous loading.



    In the example that I show you of my code, I have simulated the SQL querys with the function heavyFunction, which is intended to simulate the heavy query and the ligth one time loads.



    The issue is that this code is not working for me, because the results of the light query are not shown till the heavy query is done.



    Note: In the Rstudio console, this code works perfect...



    library(future)
    library(promises)
    plan(multiprocess)

    heavyFunction <- function(n){
    Sys.sleep(n)
    print(n)
    }


    ui <- fluidPage(
    actionButton("go","Show the data"),
    textOutput("result0sec"),
    textOutput("result10sec")

    )

    server <- function(input,output,session){


    data0 <- eventReactive(input$go,{
    heavyFunction(0)


    })

    data10 <- eventReactive(input$go,{
    heavyFunction(10)


    })
    output$result0sec <- renderText({
    data <- data0()
    future(data)%...>%print()
    })


    output$result10sec <- renderText({
    data <- data10()
    print(data)
    })




    }
    shinyApp(ui,server)


    What I'm doing wrong?










    share|improve this question

























      0












      0








      0


      1






      I have an inputButton than when you click it, 2 querys to mysql database are done. One is a heavy one (more than 10 secs) and the other is light (less than 0.01sec to get data).



      As I want to show the result of this querys on shiny app, I have intendeed to use Promises and Future packages for asyncronous loading.



      In the example that I show you of my code, I have simulated the SQL querys with the function heavyFunction, which is intended to simulate the heavy query and the ligth one time loads.



      The issue is that this code is not working for me, because the results of the light query are not shown till the heavy query is done.



      Note: In the Rstudio console, this code works perfect...



      library(future)
      library(promises)
      plan(multiprocess)

      heavyFunction <- function(n){
      Sys.sleep(n)
      print(n)
      }


      ui <- fluidPage(
      actionButton("go","Show the data"),
      textOutput("result0sec"),
      textOutput("result10sec")

      )

      server <- function(input,output,session){


      data0 <- eventReactive(input$go,{
      heavyFunction(0)


      })

      data10 <- eventReactive(input$go,{
      heavyFunction(10)


      })
      output$result0sec <- renderText({
      data <- data0()
      future(data)%...>%print()
      })


      output$result10sec <- renderText({
      data <- data10()
      print(data)
      })




      }
      shinyApp(ui,server)


      What I'm doing wrong?










      share|improve this question














      I have an inputButton than when you click it, 2 querys to mysql database are done. One is a heavy one (more than 10 secs) and the other is light (less than 0.01sec to get data).



      As I want to show the result of this querys on shiny app, I have intendeed to use Promises and Future packages for asyncronous loading.



      In the example that I show you of my code, I have simulated the SQL querys with the function heavyFunction, which is intended to simulate the heavy query and the ligth one time loads.



      The issue is that this code is not working for me, because the results of the light query are not shown till the heavy query is done.



      Note: In the Rstudio console, this code works perfect...



      library(future)
      library(promises)
      plan(multiprocess)

      heavyFunction <- function(n){
      Sys.sleep(n)
      print(n)
      }


      ui <- fluidPage(
      actionButton("go","Show the data"),
      textOutput("result0sec"),
      textOutput("result10sec")

      )

      server <- function(input,output,session){


      data0 <- eventReactive(input$go,{
      heavyFunction(0)


      })

      data10 <- eventReactive(input$go,{
      heavyFunction(10)


      })
      output$result0sec <- renderText({
      data <- data0()
      future(data)%...>%print()
      })


      output$result10sec <- renderText({
      data <- data10()
      print(data)
      })




      }
      shinyApp(ui,server)


      What I'm doing wrong?







      r shiny future






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 21 '18 at 7:17









      jffjff

      526




      526
























          1 Answer
          1






          active

          oldest

          votes


















          1














          Welcome to SO!



          This thread discusses the same issue.



          Please also see the detailed answer from Joe Cheng on GitHub.



          The main problem you are experiencing is reflected by his following statement:




          The goal, at least for this release of Shiny, is not to allow this
          kind of intra-session responsiveness, but rather, inter-session; i.e.,
          running an async operation won't make its owning session more
          responsive, but rather will allow other sessions to be more
          responsive.




          However, there are ways to work around this behaviour by running the future in a background R process with e.g. library(callr) or more convenient library(future.callr) and it's plan(callr).



          Here is a working version of your code:



          library(future)
          library(promises)
          library(future.callr)
          plan(callr)

          heavyFunction <- function(n) {
          Sys.sleep(n)
          print(n)
          }

          ui <- fluidPage(
          br(),
          actionButton("go", "Show the data"),
          br(), br(),
          textOutput("result0sec"),
          textOutput("result10sec")
          )

          server <- function(input, output, session) {
          futureData <- reactiveValues(data10 = NULL)

          data0 <- eventReactive(input$go, {
          heavyFunction(0)
          })

          observeEvent(input$go, {
          myFuture <- future({
          heavyFunction(5)
          })

          then(
          myFuture,
          onFulfilled = function(value) {
          futureData$data10 <<- value
          },
          onRejected = NULL
          )
          return(NULL)
          })

          output$result0sec <- renderText({
          data0()
          })

          output$result10sec <- renderText({
          req(futureData$data10)
          })
          }

          shinyApp(ui, server)


          The most important point here is to realize, that you shouldn't return your future directly, otherwise it will block all other actions - the observer returns nothing, it only has the side-effect of triggering the callback-function.






          share|improve this answer


























          • This works for me. Thanks!

            – jff
            Nov 22 '18 at 10:19











          Your Answer






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          1 Answer
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          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          1














          Welcome to SO!



          This thread discusses the same issue.



          Please also see the detailed answer from Joe Cheng on GitHub.



          The main problem you are experiencing is reflected by his following statement:




          The goal, at least for this release of Shiny, is not to allow this
          kind of intra-session responsiveness, but rather, inter-session; i.e.,
          running an async operation won't make its owning session more
          responsive, but rather will allow other sessions to be more
          responsive.




          However, there are ways to work around this behaviour by running the future in a background R process with e.g. library(callr) or more convenient library(future.callr) and it's plan(callr).



          Here is a working version of your code:



          library(future)
          library(promises)
          library(future.callr)
          plan(callr)

          heavyFunction <- function(n) {
          Sys.sleep(n)
          print(n)
          }

          ui <- fluidPage(
          br(),
          actionButton("go", "Show the data"),
          br(), br(),
          textOutput("result0sec"),
          textOutput("result10sec")
          )

          server <- function(input, output, session) {
          futureData <- reactiveValues(data10 = NULL)

          data0 <- eventReactive(input$go, {
          heavyFunction(0)
          })

          observeEvent(input$go, {
          myFuture <- future({
          heavyFunction(5)
          })

          then(
          myFuture,
          onFulfilled = function(value) {
          futureData$data10 <<- value
          },
          onRejected = NULL
          )
          return(NULL)
          })

          output$result0sec <- renderText({
          data0()
          })

          output$result10sec <- renderText({
          req(futureData$data10)
          })
          }

          shinyApp(ui, server)


          The most important point here is to realize, that you shouldn't return your future directly, otherwise it will block all other actions - the observer returns nothing, it only has the side-effect of triggering the callback-function.






          share|improve this answer


























          • This works for me. Thanks!

            – jff
            Nov 22 '18 at 10:19
















          1














          Welcome to SO!



          This thread discusses the same issue.



          Please also see the detailed answer from Joe Cheng on GitHub.



          The main problem you are experiencing is reflected by his following statement:




          The goal, at least for this release of Shiny, is not to allow this
          kind of intra-session responsiveness, but rather, inter-session; i.e.,
          running an async operation won't make its owning session more
          responsive, but rather will allow other sessions to be more
          responsive.




          However, there are ways to work around this behaviour by running the future in a background R process with e.g. library(callr) or more convenient library(future.callr) and it's plan(callr).



          Here is a working version of your code:



          library(future)
          library(promises)
          library(future.callr)
          plan(callr)

          heavyFunction <- function(n) {
          Sys.sleep(n)
          print(n)
          }

          ui <- fluidPage(
          br(),
          actionButton("go", "Show the data"),
          br(), br(),
          textOutput("result0sec"),
          textOutput("result10sec")
          )

          server <- function(input, output, session) {
          futureData <- reactiveValues(data10 = NULL)

          data0 <- eventReactive(input$go, {
          heavyFunction(0)
          })

          observeEvent(input$go, {
          myFuture <- future({
          heavyFunction(5)
          })

          then(
          myFuture,
          onFulfilled = function(value) {
          futureData$data10 <<- value
          },
          onRejected = NULL
          )
          return(NULL)
          })

          output$result0sec <- renderText({
          data0()
          })

          output$result10sec <- renderText({
          req(futureData$data10)
          })
          }

          shinyApp(ui, server)


          The most important point here is to realize, that you shouldn't return your future directly, otherwise it will block all other actions - the observer returns nothing, it only has the side-effect of triggering the callback-function.






          share|improve this answer


























          • This works for me. Thanks!

            – jff
            Nov 22 '18 at 10:19














          1












          1








          1







          Welcome to SO!



          This thread discusses the same issue.



          Please also see the detailed answer from Joe Cheng on GitHub.



          The main problem you are experiencing is reflected by his following statement:




          The goal, at least for this release of Shiny, is not to allow this
          kind of intra-session responsiveness, but rather, inter-session; i.e.,
          running an async operation won't make its owning session more
          responsive, but rather will allow other sessions to be more
          responsive.




          However, there are ways to work around this behaviour by running the future in a background R process with e.g. library(callr) or more convenient library(future.callr) and it's plan(callr).



          Here is a working version of your code:



          library(future)
          library(promises)
          library(future.callr)
          plan(callr)

          heavyFunction <- function(n) {
          Sys.sleep(n)
          print(n)
          }

          ui <- fluidPage(
          br(),
          actionButton("go", "Show the data"),
          br(), br(),
          textOutput("result0sec"),
          textOutput("result10sec")
          )

          server <- function(input, output, session) {
          futureData <- reactiveValues(data10 = NULL)

          data0 <- eventReactive(input$go, {
          heavyFunction(0)
          })

          observeEvent(input$go, {
          myFuture <- future({
          heavyFunction(5)
          })

          then(
          myFuture,
          onFulfilled = function(value) {
          futureData$data10 <<- value
          },
          onRejected = NULL
          )
          return(NULL)
          })

          output$result0sec <- renderText({
          data0()
          })

          output$result10sec <- renderText({
          req(futureData$data10)
          })
          }

          shinyApp(ui, server)


          The most important point here is to realize, that you shouldn't return your future directly, otherwise it will block all other actions - the observer returns nothing, it only has the side-effect of triggering the callback-function.






          share|improve this answer















          Welcome to SO!



          This thread discusses the same issue.



          Please also see the detailed answer from Joe Cheng on GitHub.



          The main problem you are experiencing is reflected by his following statement:




          The goal, at least for this release of Shiny, is not to allow this
          kind of intra-session responsiveness, but rather, inter-session; i.e.,
          running an async operation won't make its owning session more
          responsive, but rather will allow other sessions to be more
          responsive.




          However, there are ways to work around this behaviour by running the future in a background R process with e.g. library(callr) or more convenient library(future.callr) and it's plan(callr).



          Here is a working version of your code:



          library(future)
          library(promises)
          library(future.callr)
          plan(callr)

          heavyFunction <- function(n) {
          Sys.sleep(n)
          print(n)
          }

          ui <- fluidPage(
          br(),
          actionButton("go", "Show the data"),
          br(), br(),
          textOutput("result0sec"),
          textOutput("result10sec")
          )

          server <- function(input, output, session) {
          futureData <- reactiveValues(data10 = NULL)

          data0 <- eventReactive(input$go, {
          heavyFunction(0)
          })

          observeEvent(input$go, {
          myFuture <- future({
          heavyFunction(5)
          })

          then(
          myFuture,
          onFulfilled = function(value) {
          futureData$data10 <<- value
          },
          onRejected = NULL
          )
          return(NULL)
          })

          output$result0sec <- renderText({
          data0()
          })

          output$result10sec <- renderText({
          req(futureData$data10)
          })
          }

          shinyApp(ui, server)


          The most important point here is to realize, that you shouldn't return your future directly, otherwise it will block all other actions - the observer returns nothing, it only has the side-effect of triggering the callback-function.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 21 '18 at 17:42

























          answered Nov 21 '18 at 14:11









          ismirsehregalismirsehregal

          1,4241211




          1,4241211













          • This works for me. Thanks!

            – jff
            Nov 22 '18 at 10:19



















          • This works for me. Thanks!

            – jff
            Nov 22 '18 at 10:19

















          This works for me. Thanks!

          – jff
          Nov 22 '18 at 10:19





          This works for me. Thanks!

          – jff
          Nov 22 '18 at 10:19


















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