Ace Editor: Lock or Readonly Code Segment

Question

Using the Ace Code Editor can I lock or make readonly a segment of code but still allow other lines of code to be written or edited during a session?

Answer 1

You can do it easily by listening to the exec events:

// Prevent editing first and last line of editor
editor.commands.on("exec", function(e) { 
  var rowCol = editor.selection.getCursor();
  if ((rowCol.row === 0) || ((rowCol.row + 1) === editor.session.getLength())) {
    e.preventDefault();
    e.stopPropagation();
  }
});

Source: https://jsfiddle.net/tripflex/y0huvc1b/