title: Run only relevant observe functions for each tab in shinyapp
body: <p>In my shiny app I have several tabs as follows.</p>
  
  <p><a href="https://i.stack.imgur.com/HUpCI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HUpCI.png" alt="enter image description here"></a></p>
  
  <p>I have little complex functions running in this app. I think all the observe functions in the server function run when anything is done in any tab. So I need to run only relevant observe functions for relevant tab. As an example, when I am in Summary tab only the relevant observe function should run and all the other observe functions should not run. I have a code.</p>
  
  <pre><code>server &lt;- function(input, output) {
    summary &lt;- observe({....})
    occupancy&lt;- observe({....})
    Bookings&lt;- observe({....})
    Maps&lt;- observe({....})
  }
  </code></pre>
  
  <p>Is there any modification to the above code to run only the relevant observe function related to the tab opened in the app.?</p>