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SwiftUI State Management a45b2ca3778b4e6b74f96582ae927876a8ddf4a42b3b15…

- - - - ObservedObject is used to store a reference to an object that is owned by the view. This means that the object is created and destroyed along with the view, and the view has full control over the object's lifetime.
        
        ContentView has its own instance of UserSettings that it creates and owns. This means that the UserSettings object will only be accessible within the ContentView and will be destroyed when the view is deallocated.
        
        Kiểu dữ liệu phức tạp (tự định nghĩa)
        
        Chỉ định property nào sẽ được theo dõi (@ Publisher)
        
        Nếu nhiều Views sử dụng data của một Observable Object, khi object thay đổi, nó cũng sẽ tự động thông báo tới tất cả view đó.
    - - EnvironmentObject is used to store a reference to an object that is shared by multiple views in the environment. This means that the object is created and managed independently of any individual view, and it can be accessed by any view in the environment that depends on it.
        
        ContentView does not own the UserSettings object. Instead, it accesses the object from the environment, which is shared by all the views in the hierarchy. This allows multiple views to access and modify the same object and ensures that the data stays in sync across the app.
        
        Khi chúng ta có một model data mà tất cả các views đều cần tới, chúng ta có thể sử dụng EnvironmentObject.
        
        Tất cả các views có thể truy cập tới giá trị của một EnvironmentObject model nếu chúng muốn, do đó đây là một cách thuật tiện nếu chúng ta muốn chuyển dữ liệu xung quanh các Views mà không cần làm bằng tay quá nhiều.
        
        Khi model thay đổi giá trị, tất cả các Views cũng sẽ lập tức cập nhật, do đó cũng loại bỏ rủi ro các Views hiển thị chung data nhưng lại không đồng bộ.
    - - This is a specialized version of ObservedObject, and it works in almost exactly the same way.
        
        There is one important difference between StateObject and ObservedObject, which is ownership – which view created the object, and which view is just watching it.
        
        whichever view is the first to create your object must use StateObject, to tell SwiftUI it is the owner of the data and is responsible for keeping it alive.
        
        All other views must use ObservedObject, to tell SwiftUI they want to watch the object for changes but don’t own it directly.