嵌套调度组Swift

当用户在我的应用程序中创建新组时,我必须将邀请推送到数据库以及其他信息.我已经开始使用Dispatch Groups来跟踪成功发送所有信息的时间,因此我可以解除该视图.

我正在尝试为邀请使用调度组,为所有数据使用另一个调度组.这就是我所拥有的:

// Push new data to db
func createGroup(onSccess completion:@escaping () -> Void) {
    let inviteDispatchGroup = DispatchGroup()
    let dataDispatchGroup = DispatchGroup()

    let uid = FIRAuth.auth()?.currentUser?.uid
    let name = String(uid!) + "_" + nameTextField.text!

    // push invites
    dataDispatchGroup.enter()
    for invite in invites {
        inviteDispatchGroup.enter()
        let ref = FIRDatabase.database().reference().child("users").child(invite.id).child("invites")
        ref.updateChildValues([name: nameTextField.text!]) { (error, ref) -> Void in
            inviteDispatchGroup.leave()
        }
    }
    inviteDispatchGroup.notify(queue: DispatchQueue.main, execute: {
        dataDispatchGroup.leave()
    })

    // store picture
    dataDispatchGroup.enter()
    let storageRef = FIRStorage.storage().reference().child("profile_images").child("\(name).png")
    if let uploadData = UIImagePNGRepresentation(profImage.resizeImage(targetSize: CGSize(width: 500, height: Int(500*(profImage.size.height/profImage.size.width))))) {
        storageRef.put(uploadData, metadata: nil, completion: { (metadata, error) in
            dataDispatchGroup.leave()
        })
    }

    // store pet info
    dataDispatchGroup.enter()
    let petRef = FIRDatabase.database().reference().child("pets").child(name)
    petRef.setValue(["mod":uid!, "name":nameTextField.text!, "members":[uid!]]) { (error, ref) -> Void in
        dataDispatchGroup.leave()
    }

    // store user info
    dataDispatchGroup.enter()
    let userRef = FIRDatabase.database().reference().child("users").child(uid!).child("pets")
    userRef.updateChildValues([name: true]) { (error, ref) -> Void in
        dataDispatchGroup.leave()
    }

    dataDispatchGroup.notify(queue: DispatchQueue.main, execute: {
        completion()
    })
}

正如你所看到的,当invitesDipatchGroup它完成时,它的相应部分dataDispatchGroup就会被遗忘.

我是Dispatch小组的新手,想听听这是否是采取这种任务的正确方法.