CODE EXAMPLE FOR JAVASCRIPT

ref.current.selectionStart

handleKeyDown(event) {
      if (event.keyCode === 9) { // tab was pressed
          event.preventDefault();
          var val = this.state.scriptString,
          start = event.target.selectionStart,
          end = event.target.selectionEnd;
          this.setState(
              {
                  "scriptString": val.substring(0, start) + '	' + val.substring(end)
              },
              () => {
                  this.refs.input.selectionStart = this.refs.input.selectionEnd = start + 1
              });
      }
 }