The State Design Pattern is a behavioral design pattern that allows an object to change its behavior when its internal state changes. This pattern is often used in object-oriented programming to create objects that have different behaviors depending on their internal state.
In Swift, the State Design Pattern can be implemented by defining a protocol that represents the different states that an object can have. This protocol should define the methods that the object will use to change its behavior based on its internal state.
In Swift, the State Design Pattern can be implemented by defining a protocol that represents the different states that an object can have. This protocol should define the methods that the object will use to change its behavior based on its internal state.
Next, we can create a class that represents the object that will change its behavior based on its internal state. This class should have a property of the type of the state protocol that we defined earlier. This property will be used to store the current state of the object.
The class should also have a method that allows us to change its state. This method should take an instance of the state protocol as an argument, and it should use this instance to set the value of the state property.
The class should also have a method that allows us to change its state. This method should take an instance of the state protocol as an argument, and it should use this instance to set the value of the state property.
To use the State Design Pattern in our code, we first need to create a class for each state that our object can have. These classes should conform to the state protocol that we defined earlier.
Each state class should implement the methods defined in the state protocol in a way that changes the behavior of the object based on its current state. For example, if our object is a button, the "enabled" state class might implement the "onClick" method to trigger an action when the button is clicked, while the "disabled" state class might implement the "onClick" method to do nothing.
To change the state of our object, we can simply call the state-changing method on our object and pass in an instance of the appropriate state class. For example, if we want to change the state of our button from "enabled" to "disabled", we can call the state-changing method on our button object and pass in an instance of the "disabled" state class.
Each state class should implement the methods defined in the state protocol in a way that changes the behavior of the object based on its current state. For example, if our object is a button, the "enabled" state class might implement the "onClick" method to trigger an action when the button is clicked, while the "disabled" state class might implement the "onClick" method to do nothing.
To change the state of our object, we can simply call the state-changing method on our object and pass in an instance of the appropriate state class. For example, if we want to change the state of our button from "enabled" to "disabled", we can call the state-changing method on our button object and pass in an instance of the "disabled" state class.
Now we can create a class for each state that our object can have. These classes should conform to the state protocol that we defined earlier, and they should implement the methods defined in the state protocol in a way that changes the behavior of the object based on its current state:
In this example, we have implemented a simple button object that can change its behavior based on its internal state. By using the State Design Pattern, we were able to easily change the behavior of our object without having to use complex conditional statements or switch statements. This makes our code more modular and easier to maintain.
