title: GetSelection in Google Spreadsheet (selected text/row/colums)
body: <p>Im looking for something to get what is selected in a spreadsheet. I would like the users to select a couple of rows. And get the selected data in the rows in a variable.</p>
  
  <p>I know this is possible with DocumentApp. But can it be done with Spreadsheet, i haven't found anything good.</p>
  
  <p><strong>Docs:</strong></p>
  
  <pre><code> var selection = DocumentApp.getActiveDocument().getSelection();
  </code></pre>
  
  <p><strong>Spreadsheet:</strong></p>
  
  <pre><code>var selection = SpreadsheetApp.getActiveSpreadsheet().
  </code></pre>
  
  <p>Can't do the <code>.getSelection();</code> here, what could i do instead?</p>