automatic resize of rChart objects in shiny

server.R

require(rCharts)
require(shiny)
smpl<-data.frame(gene = c("gene1","gene2","gene3","gene4","gene5",
                          "gene6","gene7","gene8","gene9","gene10"),
                 direction = c("up","down","up","up","up",
                               "up","up","down","down","down"),
                 type = c("norm","norm","tum","tum","norm",
                          "tum","tum","norm","tum","tum"),
                 foldChange = c(1.3, 0.4, 1.3, 3.0, 1.6,
                                2.9, 1.3, 0.5, 0.5, 0.6))

function(input, output, session) {
  output$myChart <- renderChart({
    n <- subset(smpl, type == input$x)
    p1 <- nPlot(foldChange ~ gene, group = "direction", n, 
                type = 'multiBarChart',
                width = session$clientData[["output_plot1_width"]]) # here we get the width
    
         p1$set(dom = 'myChart')
    
    
    return(p1)
  })
  
  # optional, to display the values
  output$text1 <- renderText({
    sprintf("width = %s, height = %s",
            session$clientData[["output_plot1_width"]],
            session$clientData[["output_plot1_height"]])
  })
  
}

ui.R

library(shiny)
require(rCharts)
shinyUI(pageWithSidebar(
  headerPanel("Sample Bar Plot"),
  
  sidebarPanel(
    selectInput(inputId = "x",         
                label = "Select:",
                choices = c("norm","tum"),
                selected = "norm")
  ),
  mainPanel(
    # showOutput("myChart", "nvd3"),
    chartOutput("myChart", "nvd3"), # the chart that needs automatic resize
    plotOutput("plot1"), # to get its width value (as this widget takes 100% width by default)
    textOutput("text1"), # optional, to display the values
  )
)
)