title: Update sliderInput in Shiny reactively
body: <p>I am trying to change the values from a <code>sliderInput</code> dynamically. The difficulty now is that I want to change from a <code>sliderInput</code> with one value, to a <code>sliderInput</code> with a range, which seems not to work.</p>
  
  <p>The first actionbutton in the code below works, while the second does not what it is intended to do. </p>
  
  <p>Is the only possibility to switch to an <code>uiOutput</code> element?</p>
  
  <p><strong>Code</strong></p>
  
  <pre><code>library(shiny)
  app &lt;- shinyApp(
     ui = bootstrapPage(
        sliderInput("sld1", min = 0, max = 10, label = "y1", value = 5),
        actionButton("acb1", "Change Value"),
        actionButton("acb2", "Change Value to Range")
     ),
     server = function(input, output, session) {
        observeEvent(input$acb1, {
           updateSliderInput(session, "sld1", value = 2)
        })
        observeEvent(input$acb2, {
           updateSliderInput(session, "sld1", value = c(2,7))
        })
     })
  runApp(app)
  </code></pre>