Abstract Factory is a design pattern that allows for the creation of families of related or dependent objects without specifying their concrete classes. In other words, it provides a way to create objects without specifying their exact types. This pattern is particularly useful when creating documents, as it allows for the creation of different types of documents without having to know their specific classes.
In Swift, the Abstract Factory pattern can be implemented using protocols and classes. The first step is to create a protocol that defines the common properties and methods that all documents should have. For example, in a document creation application, the protocol might include properties such as title, author, and body, as well as a save method.
In Swift, the Abstract Factory pattern can be implemented using protocols and classes. The first step is to create a protocol that defines the common properties and methods that all documents should have. For example, in a document creation application, the protocol might include properties such as title, author, and body, as well as a save method.
Next, we can create classes that conform to the protocol and implement the specific functionality for each type of document. For example, we might have a class for a Pages document, and a class for a Numbers document. These classes would all conform to the protocol and implement the required properties and methods.
Finally, we can create a factory class that is responsible for creating instances of the different document classes. The factory class would have a method that takes a document type as a parameter and returns an instance of the appropriate class. This allows for the creation of different types of documents without having to know their specific classes.
For example, let's say we have a Pages document and a Numbers document. We could create an instance of the Pages document by calling the factory's createDocument method with `.pages` as the parameter. The factory would then return an instance of the Pages document class. Similarly, we could create an instance of the Numbers document by calling the factory's createDocument method with `.numbers` as the parameter.
The advantage of using this design pattern is that it allows for easy addition of new document types without modifying existing document classes. For example, if we wanted to add a Keynote document, we could simply create a new class called KeynoteDocument and configure it in the DocumentFactory. This new class could have distinct logic for saving and other behaviors that differ from the other classes.
The advantage of using this design pattern is that it allows for easy addition of new document types without modifying existing document classes. For example, if we wanted to add a Keynote document, we could simply create a new class called KeynoteDocument and configure it in the DocumentFactory. This new class could have distinct logic for saving and other behaviors that differ from the other classes.
So far, we have only implemented the Factory Method design pattern, as previously discussed in this blog post with a different example.
Now, let's say we are still building the same document creation application, but now we want to allow the user to create documents in different languages, such as English and Spanish. We can use the Abstract Factory Design Pattern to create the objects for these different languages.
Now, let's say we are still building the same document creation application, but now we want to allow the user to create documents in different languages, such as English and Spanish. We can use the Abstract Factory Design Pattern to create the objects for these different languages.
Let's define the classes for Pages, Numbers, and Keynote in English and Spanish
Then, we can use the factory classes to create the appropriate document object in our application:
As you can see, the main difference between the two patterns is that the Abstract Factory pattern creates a family of related objects and use them together in the factory itself.
