whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. String $type,
    2. ChatPreference chat,
    3. FilterablePreference follow,
    4. FilterablePreference like,
    5. FilterablePreference likeViaRepost,
    6. FilterablePreference mention,
    7. FilterablePreference quote,
    8. FilterablePreference reply,
    9. FilterablePreference repost,
    10. FilterablePreference repostViaRepost,
    11. Preference starterpackJoined,
    12. Preference subscribedPost,
    13. Preference unverified,
    14. Preference verified,
    15. Map<String, dynamic>? $unknown,
    )?
)

A variant of when that fallback to returning null

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? Function( String $type, @ChatPreferenceConverter()  ChatPreference chat, @FilterablePreferenceConverter()  FilterablePreference follow, @FilterablePreferenceConverter()  FilterablePreference like, @FilterablePreferenceConverter()  FilterablePreference likeViaRepost, @FilterablePreferenceConverter()  FilterablePreference mention, @FilterablePreferenceConverter()  FilterablePreference quote, @FilterablePreferenceConverter()  FilterablePreference reply, @FilterablePreferenceConverter()  FilterablePreference repost, @FilterablePreferenceConverter()  FilterablePreference repostViaRepost, @PreferenceConverter()  Preference starterpackJoined, @PreferenceConverter()  Preference subscribedPost, @PreferenceConverter()  Preference unverified, @PreferenceConverter()  Preference verified,  Map<String, dynamic>? $unknown)?  $default,) {final _that = this;
switch (_that) {
case _Preferences() when $default != null:
return $default(_that.$type,_that.chat,_that.follow,_that.like,_that.likeViaRepost,_that.mention,_that.quote,_that.reply,_that.repost,_that.repostViaRepost,_that.starterpackJoined,_that.subscribedPost,_that.unverified,_that.verified,_that.$unknown);case _:
  return null;

}
}