title: Retrieve choice name rather than value
body: <p>I have a named <code>choices</code> slot in <code>selectInput</code>, and would like to retrieve the name associated with the choice, rather than the value. </p>
  
  <p>MWE:</p>
  
  <pre><code>shinyApp(
    ui = fluidPage(
      sidebarPanel(
      selectInput("foo",
                  label = "Select choice here:",
                  choices = c("Choice 1" = "Choice1",
                              "Choice 2" = "Choice2",
                              "Choice 3" = "Choice3"),
                  selected = "Choice1",
                  multiple = TRUE),
      textOutput("nameOfChoice")
    ),
    mainPanel()),
    server = function(input, output) {
      output$nameOfChoice = renderText(input$foo[1])
    }
  )
  </code></pre>
  
  <p>Which produces:  </p>
  
  <p><img src="https://i.stack.imgur.com/FZDya.png" alt="enter image description here"></p>
  
  <p>Instead, I would like the text output to read <code>Choice 1</code>. How can I do this?</p>