whenOrNull<TResult extends Object?> method

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>({ TResult? openUrl(String url, String label, @JsonKey.new(name: 'open_in_app') bool openInApp, String style,)?, TResult? sendMessage(String message, String label, @JsonKey.new(name: 'show_in_chat') bool showInChat, String style,)?, TResult? callback(@JsonKey.new(name: 'callback_id') String callbackId, String label, Map<String, dynamic>? payload, String style,)?, })

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 url,  String label, @JsonKey(name: 'open_in_app')  bool openInApp,  String style)?  openUrl,TResult? Function( String message,  String label, @JsonKey(name: 'show_in_chat')  bool showInChat,  String style)?  sendMessage,TResult? Function(@JsonKey(name: 'callback_id')  String callbackId,  String label,  Map<String, dynamic>? payload,  String style)?  callback,}) {final _that = this;
switch (_that) {
case OpenUrlAction() when openUrl != null:
return openUrl(_that.url,_that.label,_that.openInApp,_that.style);case SendMessageAction() when sendMessage != null:
return sendMessage(_that.message,_that.label,_that.showInChat,_that.style);case CallbackAction() when callback != null:
return callback(_that.callbackId,_that.label,_that.payload,_that.style);case _:
  return null;

}
}