I have a strange NullPointerException when trying to call controller.onDeleteUser in EditUserView. I belive that rest is fine. Any ideas?

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I tried a bunch of things but they didn't work. I think (but not sure) that the controller object throws NullPointerExceptinon but I have no idea why. Even when I comment out methods calls in Controller.onDeleteUser(long id) it throws the exception. Anyone have an idea? I've spent like 8 hours on this:P

1. Following the MVC pattern, do the following by analogy with how the previous methods were implemented:
write the logic for deleting a user. After a deletion operation, the list of users must be displayed.

Assign the following methods to MVC classes:
public void fireUserDeletedEvent(long id)
public void onDeleteUser(long id)
public void deleteUserById(long id)
Note: the method that you are going to add to the View needs to be added to EditUserView.

2. Call fireUserDeletedEvent(124L) in main before calling the fireShowDeletedUsersEvent() method.

3. Refactor the MainModel class. Currently, some of the methods stop working properly when there are deleted users.
Almost all the methods that require a list of users must work only with active users.
Extract into a separate private List<User> getAllUsers() method the logic to get the list of all active users.
You already have the ability to filter active users in the List<User> filterOnlyActiveUsers(List<User> allUsers) method.
Refactor all the methods that use a list of users. They should use the list of active users.

4. Add to the Model interface the method that you put in the Model, and implement it in FakeModel: throw an UnsupportedOperationException.

Requirements:

You need to determine the correct location for the fireUserDeletedEvent(long) method, and implement it.
You need to determine the correct location for the onDeleteUser(long) method, and implement it.
You need to determine the correct location for the deleteUserById(long) method, and implement it.
You need to call the fireUserDeletedEvent(124L) method on the EditUserView object in the Solution class's main method before calling the fireShowDeletedUsersEvent() method.
In the main method, the method calls should occur in the following order: fireShowAllUsersEvent(), fireOpenUserEditFormEvent(126L), fireUserDeletedEvent(124L), fireShowDeletedUsersEvent().
You need to implement the private List<User> getAllUsers() method in the MainModel class.
You need to do some refactoring: all of the MainModel class's methods should use the list of active users.
The Model interface must declare the method that you previously implemented in the MainModel class.
In the FakeModel class, you need to throw an UnsupportedOperationException in the body of the method that was added to the Model interface.

package com.codegym.task.task36.task3608; import com.codegym.task.task36.task3608.controller.Controller; import com.codegym.task.task36.task3608.model.FakeModel; import com.codegym.task.task36.task3608.model.MainModel; import com.codegym.task.task36.task3608.model.Model; import com.codegym.task.task36.task3608.view.EditUserView; import com.codegym.task.task36.task3608.view.UsersView; public class Solution { public static void main(String[] args) { Model model = new MainModel(); UsersView usersView = new UsersView(); Controller controller = new Controller(); EditUserView editUserView = new EditUserView(); usersView.setController(controller); controller.setModel(model); controller.setUsersView(usersView); controller.setEditUserView(editUserView); usersView.fireShowAllUsersEvent(); usersView.fireOpenUserEditFormEvent(126L); editUserView.fireUserDeletedEvent(124L); usersView.fireShowDeletedUsersEvent(); } }

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Abe

Level 41 , Salt Lake City, United States

17 October 2019, 14:58

solution

I believe your problem is that you need to assign the controller to your new editUserView similar to how it has been done for the usersView (line 18) -> editUserView.setController(controller)

Marcin Olech

Level 41 , Kraków, Poland

17 October 2019, 16:04

Haha, you were right! That's working. So simple mistake. Thank you!:)