I am looking for an example of an inputformatter for text field that will be a date mm/dd/yyyy, what I am trying to do as the user types update the format. For instance user starts to type mm and the / is put in, then when the dd is typed in the / is put in.

Anyone done this or have an example? I have done it in other languages but could not find a similar way to do in flutter/dart.

This is what I have tried so far, but can not get the logic correct. Any ideas?

```
    class _DateFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(
      TextEditingValue oldValue,
      TextEditingValue newValue
      ) {
    final int newTextLength = newValue.text.length;
    int selectionIndex = newValue.selection.end;
    int usedSubstringIndex = 0;
    final StringBuffer newText = new StringBuffer();
    if (newTextLength == 2) {
      newText.write(newValue.text.substring(0, 2) + '/ ');
      if (newValue.selection.end == 3)
        selectionIndex+=3;
    }
    if (newTextLength == 5) {
      newText.write(newValue.text.substring(0, 5) + '/ ');
      if (newValue.selection.end == 6)
        selectionIndex += 6;
    }
    // Dump the rest.
    if (newTextLength >= usedSubstringIndex)
      newText.write(newValue.text.substring(usedSubstringIndex));
    return new TextEditingValue(
      text: newText.toString(),
      selection: new TextSelection.collapsed(offset: selectionIndex),
    );
  }
}

```

Thanks