title: Use of reactive dataframe in a function
body: <p>I am trying to build an app in shiny. 
  I have three sliders and i get the min max values of the sliders in a dataframe using reactive as below:</p>
  
  <pre><code>sliderValues &lt;- reactive({
  
    data.frame(
      Name = c(as.character(attributes[1]),as.character(attributes[2]),as.character(attributes[3])),
  
      MaxValue = c(input$weight_1[2],
                     input$weight_2[2],
                     input$weight_3[2]),
  
      MinValue = c(input$weight_1[1],
                     input$weight_2[1],
                     input$weight_3[1]),
  
      stringsAsFactors=FALSE
  
    )})
  </code></pre>
  
  <p>Now what I have created a function that would take as input this datafram and does some work. 
  My function is the get_uniques as below :</p>
  
  <pre><code>Combs &lt;- reactive({
  
     get_uniques(prof_test,sliderValues)
    })
  
    output$values &lt;- renderTable ({
      Combs()
                })
  
  })
  </code></pre>
  
  <p>The problem is that i get the error "no applicable method for 'xtable' applied to an object of class "character" " , it seems that the reactive dataframe creates an xtable and when i am trying to accesss the values i get this error can you help me ?
  Thank you!</p>