Shiny Programming: Highcharter library returning data to page with draggable points

This experiment is using the highcharter library to create an interactive graph and returns the value selected on the graph back to the webpage. A good way to see the effect of changing inputs on the output calculations.

The Shiny application will be called Experiment3. To set things up I will need to create 4 things

1. Create an Experiment3 folder.
2. Create a server.R script file in the Experiment2 folder.
3. Create a ui.R script file in the Experiment3 folder.
4. Create an Experiment3_App.R script file outside the Experiment3 folder.
The server.R script is

library(shiny)
library(highcharter)
library(data.table)
myData <- data.table(x=2012:2016, y=c(3900,  4200,  5700,  8500, 11900))
shinyServer(function(input, output) {
 
  #Make a copy of the data table. It will be run only once when use opens the application
  m_data <- myData
 
  output$text1 <- renderText({
    paste("You have selected ",input$xaxis_name)
  })
 
  output$text2 <- renderText({
    paste("You have selected ",input$yaxis_name)
  })
 
  output$view <- renderTable({                     
                      m_data[x==input$xaxis_name]$y <<- input$yaxis_name
                      m_data})
                 
  output$hcontainer <- renderHighchart({
   
    hc <- highchart() %>%
      hc_chart(type = "line", animation=FALSE) %>%
      hc_title(text = "A simple demo") %>%
      hc_subtitle(text = "A subtitle") %>%
      hc_xAxis(categories = m_data$x) %>%
      hc_plotOptions(
        series = list(
          point = list(
            events = list(
              drop = JS("function(){
                        Shiny.onInputChange('xaxis_name', this.category)
                        Shiny.onInputChange('yaxis_name', this.y)
                        }")))
          ,stickyTracking = FALSE
          ),
        column = list(
          stacking = "normal"
        ),
        line = list(
          cursor = "ns-resize"
        )) %>%
      hc_add_series(      
        data = m_data$y,name = "Downloads",draggableY = TRUE
      )       
    hc   
  })
})

The ui.R script is

library(shiny)
shinyUI(
  fluidPage(
            titlePanel("High Charter plotting"), 
            highchartOutput("hcontainer",height = "500px"),
            textOutput("text1"),
            textOutput("text2"),
            tableOutput("view")           
           )
)

The experiment3_app.R script is

 # Experiment 3: Using highcharter for interactive plotting and feedback
library(shiny)
runApp("experiment3") 

Lets drag the mid point