title: Shiny - true or false value when check a checkbox in datatable
body: <p>i have problem with R shiny code, what i must do, when i want to see the true or false value in checkbox? because when i try print(input$row1) the result is NULL, and when i give check in the checkbox there are no respon in print statement. this is the code :</p>
  
  <pre><code>library(shiny)
  library(DT)
  mymtcars = mtcars
  mymtcars$id = 1:nrow(mtcars)
  runApp(
    list(ui = pageWithSidebar(
      headerPanel('Examples of DataTables'),
      sidebarPanel(
  
      ),
      mainPanel(
        uiOutput("mytable")
      )
    )
    , server = function(input, output, session) {
  
      output$mytable = renderUI({
        addCheckboxButtons &lt;- paste0('&lt;input type="checkbox" id="row', mymtcars$id, '"&gt;',"")
        yyy&lt;- cbind(mymtcars[, names(mymtcars[,2:4]), drop=FALSE],Pick=addCheckboxButtons)
  
        #try
        print(input$row1) #didnt work
        print(input$row2) #didnt work
  
        #Display table with checkbox buttons
        list(
        renderDataTable(yyy,
                      options = list(orderClasses = TRUE,
                                     lengthMenu = c(5, 25, 50),
                                     pageLength = 25, 
                                     callback = JS("function(table) {
                                                   table.on('change.dt', 'tr td input:checkbox', function() {
                                                   setTimeout(function () {
                                                   Shiny.onInputChange('rows', $(this).add('tr td input:checkbox:checked').parent().siblings(':last-child').map(function() {
                                                   return $(this).text();
                                                   }).get())
                                                   }, 10); 
                                                   });
      }")),escape = FALSE
  
                      ))
        } 
    )
      }
        )
                      )
  </code></pre>