title: How to force flush a user's input?
body: <p>I was wondering if it is possible to force flush of a user input from a script.</p>
  
  <p>The context is the following : I have a sheet in which people are supposed to input data, and a button where they click when they are done, which will process the data.</p>
  
  <p>It happens that sometimes people double click a cell, write what they want, but then they click the button before hitting return. Thus the script sees the cell as still empty.</p>
  
  <p>Would there be a way to either force flush with what they have currently typed, or detect that a cell is currently being edited ?</p>