title: R Shiny - How to use a tableOutput as vector or data.frame
body: <p>Greetings and thanks for your help,</p>
  <p>I can't use a data.frame (created on server.R) in ui.R.
  The reason is obvious: a <code>tableOutput()</code> is not a data.frame nor a vector.
  I need to do this because the <code>selectInput(&quot;ops&quot;,...)</code> receives that table from server.R, as it is the result of a function applied to an input there.
  The function is long, so i just made this <code>data.frame(c(1,2),c(3,4),c(5,6))</code>. Anyhow, the point is the same.</p>
  <h2>Question:</h2>
  <p>Even though i know why is not working, I am not able to make it work.
  What I am looking for is a way to get the information from the <code>tableOutput()</code> in a table-like way, to use it in the <code>selectInput(choices = ...)</code> dropdown list.</p>
  <p>If you run this code you'll notice the <code>selectInput()</code> is just showing options: &quot;name&quot;, &quot;id&quot;, &quot;class&quot;.
  I want it to show: 1, 2. or 3, 4. or 5, 6...</p>
  <p>Thank you.</p>
  <pre><code>library(shiny)
  shinyApp(
      ui = fluidPage(
          sidebarLayout(
              sidebarPanel({p(&quot;&quot;)}),
              mainPanel({
                  tabPanel(&quot;Asignar tipo&quot;,
                      selectInput(
                          &quot;ops&quot;,
                          &quot;Operations&quot;,
                          tableOutput(&quot;impsTabla&quot;),
                          multiple=TRUE,
                          selectize=TRUE
                      ),
                      br(),
                      tableOutput(&quot;impsTabla&quot;)
                  )
              })
          )
      ), 
      server = function(input, output){
          output$impsTabla&lt;- renderTable(
              data.frame(c(1,2),c(3,4),c(5,6))
          )
      }
  )
  </code></pre>