to illustrate this let's think of Barbie's and GI-Joes, in essence they're both dolls, they both have a head, two arms, two legs, a torso, and neither have genitals, but they can be thought of as distinct Objects. They can both be made with the same factory just with a slightly different setup;
Now our application has an AbstractFactory, this abstract factory can be one of two things either a GiJoeFactory or a Barbie factory, which create either GiJoes or Barbies. Both the GiJoes and Barbies realize the IDoll interface.
The difference between a Factory pattern and an Abstract Factory Pattern to me is that in the former the application has either a BarbieFactory or a GiJoeFactory where as with the later the application can decide which factory to use. Let's take a look at the code example.
first let's setup our dolls.
interface IDoll
{
string Name { get; set; }
string SayHi();
}
class GiJoe :
{
public string Name { get; set; }
public string SayHi()
=> $"\r\nI'm a GiJoe, my name is {Name}";
}
class Barbie :
{
public string Name { get; set; }
public string SayHi()
=> $"\r\nI'm a Barbie, my name is {Name}";
}
Next let's look at our factories
interface IDollFactory { IDoll CreateDoll(); }
class GiJoeFactory :
{
static Random rnd = new Random(DateTime.Now.Millisecond * DateTime.Now.Second);
string[] names = new[] { "Joe", "Dan", "Rick", "Jack" };
public IDoll CreateDoll() => new GiJoe { Name = names[rnd.Next(names.Length)] };
}
class BarbieFactory :
{
static Random rnd = new Random(DateTime.Now.Millisecond * DateTime.Now.Second);
string[] names = new[] { "Barbie", "Jessica", "Jenifer", "Nicole" };
public IDoll CreateDoll() => new Barbie { Name = names[rnd.Next(names.Length)] };
}
now since this is a contrived example there's very little of interest here other than the fact that the private names array varies between the two factories to allow some slight variance within the two factories. next let's look at the application itself.
class Program
{
static IDollFactory dollFactory =
null;
static void Main(string[] args)
{
int selection = -1;
do
{
switch (selection)
{
case 1:
dollFactory = new BarbieFactory();
break;
case 2:
dollFactory = new GiJoeFactory();
break;
default:
dollFactory = null;
selection = -1;
break;
}
if (dollFactory != null)
Console.WriteLine(dollFactory.CreateDoll().SayHi());
ConsoleDollType();
} while (int.TryParse(Console.ReadKey().KeyChar.ToString(),
out selection) && selection !=
0);
}
static void
ConsoleDollType()
{
Console.WriteLine("what type of toy would you like?");
Console.WriteLine("1) a doll");
Console.WriteLine("2) an action figure");
Console.WriteLine("0) exit");
}
}
