shiny - R reactive histogram

Question

I am learning the Shiny interface for R and working through the first example.

The histogram changes based on the slider input. How do I have it update continuously, while the slider is moving? Right now, it only updates when the slider stops moving.

ui.R

library(shiny)

# Define UI for application that draws a histogram
shinyUI(fluidPage(

  # Application title
  titlePanel("Hello Shiny!"),

  # Sidebar with a slider input for the number of bins
  sidebarLayout(
    sidebarPanel(
      sliderInput("bins",
                  "Number of bins:",
                  min = 1,
                  max = 50,
                  value = 30)
    ),

    # Show a plot of the generated distribution
    mainPanel(
      plotOutput("distPlot")
    )
  )
))

server.R

library(shiny)

# Define server logic required to draw a histogram
shinyServer(function(input, output) {

  # Expression that generates a histogram. The expression is
  # wrapped in a call to renderPlot to indicate that:
  #
  #  1) It is "reactive" and therefore should re-execute automatically
  #     when inputs change
  #  2) Its output type is a plot

  output$distPlot <- renderPlot({
    x    <- faithful[, 2]  # Old Faithful Geyser data
    bins <- seq(min(x), max(x), length.out = input$bins + 1)

    # draw the histogram with the specified number of bins
    hist(x, breaks = bins, col = 'darkgray', border = 'white')
  })
})

What I have tried:

#server.R
    library(shiny)

    shinyServer(function(input,output) {
                    x<-faithful[,2]
                    bins <- reactive({
                            seq(min(x),max(x),length.out=input$bins+1)
                    })

                    output$distPlot <- renderPlot({
                    hist(x,breaks=bins(),col='darkgray',border='white')})
    })

Is there a way to make it react faster/real-time?

Answer 1

Thanks to Dean's response I investigated the shinyCustom package in github.

Here is my solution:

#Shiny UI
library(shiny)
library(shinyCustom)

# Define UI for application that draws a histogram
shinyUI(fluidPage(

  # Application title
  titlePanel("Hello Shiny!"),

  # Sidebar with a slider input for the number of bins
  sidebarLayout(
    sidebarPanel(
      useShinyCustom(slider_delay = "0"), #make a call to shinyCustom, where there is no delay
      customSliderInput("bins", #Use customSliderInput instead of sliderInput
                  "Number of bins:",
                  min = 1,
                  max = 50,
                  value = 30)
    ),

    # Show a plot of the generated distribution
    mainPanel(
      plotOutput("distPlot")
    )
  )
))

App now updates as you move the slider