CODEWITHSUNDEEP
rinputshinyoutput
Chloe_pa
Chloe_pa

Reputation: 213

How to use inputs in the Ui part?

I'd like to be able to use results of an input in the Ui part of my shiny app, to set the default value and the maximum of a numericInput.

Here is the "idea" of the ui part i'd like :

ui <- (

 numericInput("n21","choose input1",min=0,max=100000,value=5107,step=1),
 numericInput("n22","choose input2",min=0,max=2000,value=1480.3/40),

 # here i'd like to define value and max with the result of inputs (n23) 
 numericInput(inputId="nb_rows","Number of rows to show",value=n23,min=1,max=n23)
 tableOutput(outputId = "data")
)

And the server part :

server <- function(input,output,session){
  ....
  RE <- reactive({
   n21 <- input$n21
   n22 <- input$n22
   n23 <- n21%/%n22

   return(head(data, n=input$nb_rows))
  })

  output$data <- renderTable({RE()})


}

Any suggestions?

Upvotes: 0

Views: 29

Answers (1)

J0ki
J0ki

Reputation: 302

You will need to use the observe function to change the numericinput that you want to change so we will do:

`server <- function(input,output,session){
  ....
  RE <- reactive({
   n21 <- input$n21
   n22 <- input$n22
   n23 <- n21%/%n22

   return(n23)
  })`

`    observe({
      x <- RE()

      # Can use character(0) to remove all choices
      if (is.null(x))
        x <- character(0)

      # Can also set the label and select items
      updateNumericInput(session, "nb_rows",
                        label = "Number of rows to show",
                        value = x,
                        min = 1,
                        max = x
      )
    })`

And then you re-make the output table function

I hope it helps.

Upvotes: 1

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