Re: [shinyapps-users] Creating non reactive instances of reactive varaibles

[Tareef Kawaf]

This feels more like a shiny question so I am moving it to shiny-discuss, I am guessing that you are looking for is a way to pick off the data using something like the isolate() call.

On Sun, May 22, 2016 at 7:07 PM, Michael <michaela...@gmail.com> wrote:

I am not sure whether this is possible or not.

For example say a user enters some number into a reactive function they hit a button which multiplies every cell.

Then when they like those numbers they can hit another button which will send those particular values to a data frame (this data frame being completely non reactive).

In short I am asking, can you make reactive values non reactive? To me this seems like something pretty important.

Thanks,

Michael

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[Michael]

I am not sure whether this is possible or not.

For example say a user enters some number into a reactive function they hit a button which multiplies every cell.

Then when they like those numbers they can hit another button which will send those particular values to a data frame (this data frame being completely non reactive).

In short I am asking, can you make reactive values non reactive? To me this seems like something pretty important.

Here is my code in which I am trying to make tabplot become an unreactive copy. 

library(shiny)

library(rhandsontable)

seq1 <- seq(1:6)

mat1 <- matrix(seq1, 2)

tabplot<-data.frame(car=numeric(2),num=numeric(2),truck=numeric(2))

did_recalc <- FALSE

ui <- fluidPage(

  rHandsontableOutput('table'),

  tableOutput('result'),

  textOutput('ca'),

  actionButton("goButton","Confirm"),

  verbatimTextOutput("otest"),

  actionButton("checkButton","Apply"),

  br(),

  actionButton("recalc", "Return to original values")

  

)

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

  

 # tabplot<-data.frame(car=numeric(2),num=numeric(2),truck=numeric(2))

  seq1 <- seq(1:6)

 # mat1 <- matrix(seq1, 2)

  

  mat1<- data.frame(x=1:2,y=3:4,z=5:6)

  #creates reactive values for the data frame

  #obviously they have to be reactive values to function with the rhandsontable which is being continuously updated

  #as the documentation says "values taken from the reactiveValues object are reactive but the object itself is not

  values <- reactiveValues(data=mat1)

  

  #if recalc --- which connects to an action button in the ui is hit, values goes back to original data frame

  observe({

    input$recalc

    values$data<-mat1

  })

  

  #Where the magic happens

  output$table <- renderRHandsontable({

    rhandsontable(values$data,selectCallback = TRUE)

  })

  

  #this changes the handsontable format to an r object

  observe({

    if(!is.null(input$table))

      values$data <-hot_to_r(input$table)

  })

  

  #Here we create a reactive function that creates a data frame of the rhandsontable output but it is a reactive function

  fn<-reactive({

    co<-data.frame((values$data))                                

    return(co)

  })

  

  #Bit of testing, this demonstrates that the fn() is only updated after the button is pressed

  output$result<-renderTable({

    input$goButton

    isolate({

      fn()

    })

  })   

  

  #observe({

 #   if(!is.null(input$table))

 #     values$data <-hot_to_r(input$table)

 # })

 

 # observe({

   # if(did_recalc = FALSE)

#  tabplot<-reactive({                              #Format co[desired row:length(colums)][desired column] 

  #observeEvent(input$checkButton,{

  

    isolate({ 

      tabplot[1,1:3][1]<-fn()[1,1:3][1]

      tabplot[1,1:3][2]<-fn()[1,1:3][2]

      tabplot[1,1:3][3]<-fn()[1,1:3][3]

      

      tabplot[2,1:3][1]<-fn()[2,1:3][1]

      tabplot[2,1:3][2]<-fn()[2,1:3][2]

      tabplot[2,1:3][3]<-fn()[2,1:3][3]

    })

  observe({

    input$checkButton

    output$ca<-renderText({

      tabplot$car 

      cat('\nAccessing Subset with $:', tabplot$car)

      cat('\nAccessing specific cell:',tabplot[1,3])

      cat('\nAccessing specific cell:',tabplot[[1]])

      cat('\noperations on specific cell:',tabplot[1,3]*2)

    })

  })

  

})

shinyApp(ui = ui, server = server)