13 January 2019, 00:00

the prototype pattern

Name: Prototype

Type: Creational

Use when you want to:

Clone an object rather than create one

From Wikipedia:

The prototype pattern is a creational design pattern in software development. It is used when the type of objects to create is determined by a prototypical instance, which is cloned to produce new objects.

Real World Example:

Remember dolly? The sheep that was cloned! Well we can clone objects aswell

Main Purpose:

Create object based on an existing object through cloning.

Typescript Code Example:

enum SheepType{ 
    mountain,
    fluffy,
    friendly,
}

class Sheep{ 
    constructor(private _name: string, private _category: SheepType) { 

    }

    setName(name: string) { 
        this._name = name;
    }

    setCategory(category: SheepType) { 
        this._category = category
    }

    identify() { 
        return "Hi my name is " + this._name + " and I'm a " + SheepType[this._category] + " sheep."
    }

    static clone(sheep: Sheep): Sheep { 
        let copy = <Sheep>{}
        
        return new Sheep(sheep._name, sheep._category)
    }
}
const sheepy = new Sheep('sheepy', SheepType.mountain);

const dolly = Sheep.clone(sheepy);

Full Example: