title: Shiny checkbox observe event stuck in infinite loop
body: <p>I have quite an interesting problem. I have a number of checkboxes for input in Shiny (naturally), everything works fine, if I click a checkbox and wait like half a second and click the next (the screen dims to grey and then the checkbox is checked and the I can continue). However, if I check a checkbox without waiting (just before the screen goes grey) shiny ends up in an infinite loop.</p>
  
  <p>I cannot give the full code, but the just of it is provided.</p>
  
  <pre><code>obs_ev &lt;- "c(input[['cbox_gr1']], input[['cbox_gr2']]")
  
  observeEvent(eval(parse(text = obs_ev)), {
  
  dat &lt;- eval(parse(text = obs_ev))
  v1  &lt;- input$v2
  v2  &lt;- v2_short_list[v2_list == input$v2]
  
  # Only need the first one since v1 and v2 are the same for all inputs
  dat_temp &lt;- dat[1]
  
  # Dataframe to update
  v1_updt &lt;- gsub("_-_", "\\2", dat_temp)
  v2_updt &lt;- gsub("_-_", "\\3", dat_temp)
  
  focused.df      &lt;- paste0(gsub(" ", "_", v1), "_", v2)
  working.df.name &lt;- paste0(v1_updt, "_", v2_updt)
  
  if (focused.df == working.df.name) {
  
    print(dat)
  
    # V3 to update
    v3_updt &lt;- gsub("_-_", "\\1", dat_temp)
  
    reactive.df.name &lt;- paste0(v1_updt, "_", v2_updt, "_react")
  
    # Rows to update
    rows_updt &lt;- as.numeric(gsub("_-_", "\\4", dat))
  
    # Update data based on checkbox input
    eval(parse(text = paste0("temp_updt &lt;- ", working.df.name)))
    tbc &lt;- temp_updt[[v3_updt]][!temp_updt$key %in% rows_updt]
    tbc[tbc == 2] &lt;- 1
    temp_updt[[v3_updt]][!temp_updt$key %in% rows_updt] &lt;- tbc
    temp_updt[[v3_updt]][rows_updt] &lt;- 2
  
    # Overwrite the dataframe (not the reactive one, but instead the one that the reactive dataframe is linked to)
    eval(parse(text = paste0(working.df.name, " &lt;&lt;- temp_updt")))
  }
  })
  </code></pre>
  
  <p>Again, the code is working just fine, except for the delay in the click - the fact that Shiny 'fades' in and out when I click on a checkbox, even more, the fade doesn't bother me that much (I would like it gone though) the fact that if I click before the fade, the whole thing ends up in a loop</p>