In object-oriented programming, the command pattern is a behavioural 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.
Three terms always associated with the command pattern are client, invoker and receiver. The client instantiates the command object and provides the information required to call the method at a later time. The invoker decides when the method should be called. The receiver is an instance of the class that contains the method's code.
Using command objects makes it easier to construct general components that need to delegate, sequence or execute method calls at a time of their choosing without the need to know the owner of the method or the method parameters.
Read more about Command Pattern: Uses, Structure, Terminology, Example
Famous quotes containing the words command and/or pattern:
“Children from humble families must be taught how to command just as other children must be taught how to obey.”
—Friedrich Nietzsche (1844–1900)
“Why it was that upon this beautiful feminine tissue, sensitive as gossamer, and practically blank as snow as yet, there should have been traced such a coarse pattern as it was doomed to receive; why so often the coarse appropriates the finer thus, the wrong man the woman, the wrong women the man, many years of analytical philosophy have failed to explain to our sense of order.”
—Thomas Hardy (1840–1928)