title: R Shiny - add tabPanel to tabsetPanel dynamically (with the use of renderUI)
body: <p>I am developing a shiny application in which I use <code>tabsetPanel</code>, which is generated when user enters some particular input. Thus, I want to use <code>renderUI</code> function to make a tabsetPanel appear / disappear. </p>
  
  <p>My struggle now is that <strong>number of</strong> <code>tabPanel</code> elements (arguments of <code>tabsetPanel</code>) <strong>also depends on user input</strong>, in the way: sometimes I need 1 one, other times I want more <code>tabPanels</code>. </p>
  
  <p>How to make it? I tried including <code>conditionPanel</code> or including simple <code>if()...</code> condition in the <code>tabsetPanel</code> argument, but it (rather not surprisingly...) did not work.</p>