CSC/ECE 517 Fall 2010/ch4 4f sv: Difference between revisions
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== What is Command Pattern ? == | == What is Command Pattern ? == | ||
The command pattern is a design pattern in which an object is used to represent and encapsulate all the information needed to call a method at a later time. This information includes the method name, the object that owns the method and values for the method parameters. It encapsulates a request as an object and gives it a known public interface. It ensures that every object receives its own commands and provides a decoupling between sender and receiver. In this case a sender is an object that invokes an operation, and a receiver is an object that receives the request and acts on it. | The command pattern is a design pattern in which an object is used to represent and encapsulate all the information needed to call a method at a later time. This information includes the method name, the object that owns the method and values for the method parameters. It encapsulates a request as an object and gives it a known public interface. It ensures that every object receives its own commands and provides a decoupling between sender and receiver. In this case a sender is an object that invokes an operation, and a receiver is an object that receives the request and acts on it. | ||
== Why and When do we use a Command Pattern? == | |||
Command Pattern comes into picture when there is a need to store objects behaviour as a command and its state. 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. | |||
Revision as of 22:17, 15 October 2010
Command Pattern in static and dynamic languages
What is Command Pattern ?
The command pattern is a design pattern in which an object is used to represent and encapsulate all the information needed to call a method at a later time. This information includes the method name, the object that owns the method and values for the method parameters. It encapsulates a request as an object and gives it a known public interface. It ensures that every object receives its own commands and provides a decoupling between sender and receiver. In this case a sender is an object that invokes an operation, and a receiver is an object that receives the request and acts on it.
Why and When do we use a Command Pattern?
Command Pattern comes into picture when there is a need to store objects behaviour as a command and its state. 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.