client/server interaction with shiny - part 1

server.R

library(shiny)

shinyServer( function(input, output, session) {
  
  output$results <- renderPrint({
    input$mydata
  })
  
})

ui.R

library(shiny)

shinyUI( bootstrapPage(  
  
  # a div named mydiv
  tags$div(id="mydiv", 
           style="width: 50px; height :50px; left: 100px; top: 100px;
           background-color: gray; position: absolute"),
  
  # an element for unformatted text
  verbatimTextOutput("results"),
  
  # javascript code to send data to shiny server
  tags$script('
    document.getElementById("mydiv").onclick = function() {
      var number = Math.random();
      Shiny.onInputChange("mydata", number);
    };
  ')
))