Prototype Pattern

Intent

Specify the kinds of objects to create using a prototypical instance, and create new objects by copying this prototype instead of depending on the new operator.

When to use

1. When the object instantiation from the beginning takes a lot of time.

2. When we want to specify an instance of the class to use it as a breeder of all future instances.

3. To avoid building a class hierarchy (seperate classes or factories) that parallels the class hierarchy of the products.

4. If we want to instantiate the same class with a minimal change of state, it's more appropriate to clone the instance and change its state to the required state.

Structure

• Prototype: defines the interface for cloning

• ConcretePrototype: implements the operation for cloning itself.

• Client: creates a new object by asking a prototype to clone itself.

• Registry: optional class that saves the frequently used prototypes, either before compilation, or even in runtime.

Examples

Source Code	UML
Example 1	// TODO
Example 2	// TODO

You can find the tests here.