Chart (rCharts) is not shown in the web page (Shiny)

Question

I am trying to embed the interactive chart from rCharts package. To embed the chart I have used the example from here (Shiny app).

The example works well but my prototype works without the chart output (no errors have been reported). My script is as follows:

ui.r:

library(shiny)
require(rCharts)

shinyUI(fluidPage(

# Application title
titlePanel("Old Faithful Geyser Data"),

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

# Show a plot of the generated distribution
mainPanel(
  showOutput("myChart", "polycharts")
  )
 )
))

server.r:

library(shiny)
require(rCharts)

 shinyServer(function(input, output) {


observeEvent(input$bins,{
df2 <<- data.frame(x=c(1:input$bins),y=c(1:input$bins)) 


})



output$myChart <- renderChart({

  print(df2)  
  p1 <- rPlot(df2$x,df2$y, data = df2, color='green', type = 'point')
  p1$addParams(dom = 'myChart')
  return(p1)

})

})

Answer 1

I have reviewed your code and here are some pointers:

1) rPlot is taking data as x~y along with color argument

2) It is better if you use the eventReactive and assign it to df2() instead of observe and <<- global assignment operator

rm(list = ls())
library(shiny)
require(rCharts)

server <- function(input, output) {

  df2 <- eventReactive(input$bins,{data.frame(x=c(1:input$bins),y=c(1:input$bins))})
  output$myChart <- renderChart({
    p1 <- rPlot(x~y, data = df2(), color='green', type = 'point', color = 'x')
    p1$addParams(dom = 'myChart')
    return(p1)
  }) 
}

ui <- fluidPage(
  # Application title
  titlePanel("Old Faithful Geyser Data"),

  # Sidebar with a slider input for number of bins
  sidebarLayout(sidebarPanel(sliderInput("bins","Number of bins:", min = 1,max = 50,value = 30)),
                # Show a plot of the generated distribution
                mainPanel(showOutput("myChart", "polycharts"))
  )
)
shinyApp(ui, server)