title: How to listen for more than one event expression within a Shiny eventReactive handler
body: <p>I want two different events to trigger an update of the data being used by various plots / outputs in my app. One is a button being clicked (<code>input$spec_button</code>) and the other is a point on a dot being clicked (<code>mainplot.click$click</code>). </p>
  
  <p>Basically, I want to listed for both at the same time, but I'm not sure how to write the code. Here's what I have now:</p>
  
  <p>in server.R:</p>
  
  <pre><code>data &lt;- eventReactive({mainplot.click$click | input$spec_button}, {
      if(input$spec_button){
        # get data relevant to the button
      } else {
        # get data relevant to the point clicked
      }
    })
  </code></pre>
  
  <p>But the if-else clause doesn't work </p>
  
  <p><code>Error in mainplot.click$click | input$spec_button : 
    operations are possible only for numeric, logical or complex types</code></p>
  
  <p>--> Is there some sort of action-combiner function I can use for the <code>mainplot.click$click | input$spec_button</code> clause?</p>