CODEWITHSUNDEEP
javadesign-patternsgraphfactory-pattern
nawara
nawara

Reputation: 1167

Is this right usage Of factory method

As i understood Factory design pattern is used to create object instead of constructors

in a previous question i explained my situation which is :
I have a complex Network represented as hypergraph Hypergraph vertices are from various type :image,tag ....
I should create thousand of vertices it will be hard to create it manually! so i thought that factory pattern may help me in this case

I drew two possible diagram using yUML but i can't decide what is the most appropriate to my situation

first diagram

second diagram

Upvotes: 3

Views: 141

Answers (2)

acdcjunior
acdcjunior

Reputation: 135792

Actually, both depict the Factory Method pattern.

But, as we are speaking of mutiple factories, the first image is a better, less coupled, more extensible, easier to maintain approach.

Just, in the first image, as you have a yet small diagram, it is better to put a dashed line from AbstractVertexFactory to Vertex, as there is a dependency relationship between these classes.

Also, the second image is missing all the dashed dependency lines. This does not make this diagram incorrect, and it still does depict the factory method pattern, the only drawback is that it is more confusing without the mentioned lines.

Explanation of why the first is better than the second:

  • Less coupled: In the first case, if you change/delete the TagVertex, no clients of the ImageFactory (and potetially other factories) are affected.
  • More extensible and easier to maintain: Same principle. If you change a product (Vertex in your scenario) class, no client of other factory is affected. Also you can add factories freely without need to change existing code.

Upvotes: 2

Atul
Atul

Reputation: 1590

Diagram one is the correct option.

Abstract factory is used to create families of related or dependent objects. In this case , Abstract veretx factory (through use of Tag or Image factory concrete classes )will create concrete products (Tag Vertex and Image vertex ) respectively.

In case of second diagram , there is no relation between products and abstract factory. Abstract factory should create the concrete products (by making use of concrete factory classes Image Vertex and Tag Vertex in this case)

Upvotes: 2

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