title: Update a value to an input$value without input$ logic
body: <p>I want to change the value of an <code>input$value</code> that my shinyapp generates. To do this </p>
  
  <p>I have tried with:</p>
  
  <pre><code>observeEvent(input$click,
               input$vis$start[1]&lt;- "2019-01-09T03:00:00.000Z"
              )
  </code></pre>
  
  <p>But the response that I have is: </p>
  
  <pre><code>Warning: Error in $&lt;-.reactivevalues: Attempted to assign value to a read-only reactivevalues object
    [No stack trace available]
  </code></pre>
  
  <p>All the code: </p>
  
  <pre><code>library(timevis)
  library(shiny)
  
  
  data &lt;- data.frame(
    start=c("2019-01-10","2019-01-11"),
    end =  c("2019-01-11","2019-01-12")
    )
  
  ui &lt;- fluidPage(
    br(),
    br(),
    timevisOutput("vis"),
    tableOutput("table"),
    actionButton("click","da")
  )
  
  server &lt;- function(input,output){
    output$uno &lt;- renderTimevis(
  
      timevis(data,options=list(editable=TRUE,stack=FALSE))
    )
  
  
    observeEvent(input$click,
  
                 input$vis_data$start[1]&lt;- "2019-01-09T03:00:00.000Z"
  
                 )
    output$table &lt;- renderTable(
      input$vis_data
  
    )
  
  }
  
  shinyApp(ui,server)
  </code></pre>