Now FormGroup and FormControl allows specify types, by default they use any. We applied types to the single FormControl that we have, but applying them to FormGroup requires more work because we need to type every control inside the FormGroup. Also, when retrieving the data using formGroup.value all the values can be undefined because controls can be disabled.

I did a Proof of concept in the calendar edit-event page, in this gist I put how I defined and created the FormGroup:

https://gist.github.com/dpalou/a55ec47fb225318b3e7fb4f612109b32