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What are the main uses of command design pattern?
In object-oriented programming, the command pattern is a behavioral design pattern in which an object is used to encapsulate all information needed to perform an action or trigger an event at a later time.
Does the command pattern require undo?
Just as a macro, the Command design pattern encapsulates commands (method calls) in objects allowing us to issue requests without knowing the requested operation or the requesting object. Command design pattern provides the options to queue commands, undo/redo actions and other manipulations.
What is a template method?
The template method is a method in a superclass , usually an abstract superclass, and defines the skeleton of an operation in terms of a number of high-level steps. These steps are themselves implemented by additional helper methods in the same class as the template method.
Command design pattern is a behavioral design pattern. We use it to encapsulate all the information required to trigger an event. Some of the main uses of Command pattern are: Graphic User Interface (GUI): In GUI and menu items, we use command pattern. By clicking a button we can read the current information of GUI and take an action.
Why do we use simple if-else in a command pattern?
By using simple if-else we are coding to implementation rather than interface. Also there is tight coupling. So what we want to achieve is a design that provides loose coupling and remote control should not have much information about a particular device. The command pattern helps us do that.
How does the command pattern work in Python?
The Command pattern suggests that GUI objects shouldn’t send these requests directly. Instead, you should extract all of the request details, such as the object being called, the name of the method and the list of arguments into a separate command class with a single method that triggers this request.
When to use the memento command design pattern?
Sometimes for undo/redo actions the command should store more information about the state of the receiver objects. A good idea in such cases is to use the Memento Pattern. Another usage for the command design pattern is to run commands asynchronous in background of an application.