Caio Raphael

Definitions:
- "Structural design patterns explain how to assemble objects and classes into larger structures, while keeping these structures flexible and efficient."
- "Structural design patterns are design patterns that ease the design by identifying a simple way to realize relationships among entities."
Types of Structural Patterns .
Types of Structural Patterns .
Comparison between Structural Patterns .
- A comparison between Adapter, Facade, Proxy, Decorator and Bridge is made.
- {1:42 -> 10:10}
  - Brief explanations of the patterns and UML drawings.
  - The rest of the video is just discussion about the drawings.
Comparison between Composite Pattern and Decorator Pattern .
- Both use recursion and have a very similar UML diagram, with the difference that "the Decorator uses Abstractions in the definition of the Decorator, while the Composite uses Concretions" (nah, I didn't care enough about these methods to care).
- "For a Decorator to be a Decorator, it needs to Decorate something, only one thing, to be specific. If you have a Decorator that decorates many things, you'll have a Composite Pattern, not a Decorator Pattern."
  - The idea is that if a "Decorator decorates many things", you create a Tree system.

The pattern is based on "wrapping" an object in other objects to change the internal behavior at runtime.
Decorator Pattern .
- {~28:30}
  - It becomes clearer what the idea of this pattern is: It uses a recursive system where the Wrapper calls what is inside it recursively, and at each interaction modifications are made to the final return of the function.
- {37:00}
  - Code examples are shown, also helping a lot to understand the pattern.
- {43:37}
  - It is shown how the coffee example used by the book is ultra over-engineering, being unnecessary and confusing; the presenter simply suggests using a list of ingredients and iterating the list.
Review :
- I did not like this pattern, it feels like over-engineering in many moments.

Also known as a 'Simple Wrapper'.
Makes two incompatible interfaces compatible, just like a plug adapter.
Adapter Pattern .
Review :
- Useful only for cases of creating compatibility between two things, very specific.

Creates a "disguise" for complex interactions in the code to make interaction more friendly.
Facade Pattern .
- Implementation was not necessarily explained, just a discussion about the subject.
Review :
- It seems like a kind of 'macro' to communicate with complex things or to create complex things.
- Its use is interesting, but it gives me the impression that if you have to use this kind of thing, the code is huge and messy.

"Adds behavior to an object, with the intent to control access to that object".
Proxy Pattern .
- {24:09 -> 27:02}
  - The UML diagram is explained, showing the relationship between the Object, the Interface and the Proxy.
- From what I understand, the Proxy implements the same Interface as the Object while also holding a reference to the Object. This allows the Proxy to control access to the Object if the function call is made through the Proxy.
  - The presenter says "it's like caching".
  - I did not understand why the Proxy must implement the Object's Interface.
Review :
- Seems useful for access control and greater control of the object, but I found the pattern a bit confusing due to the Proxy's use of the Interface.

I did not understand this pattern very well.
The pattern seems to have a rather loose definition, kind of whatever.
Bridge Pattern .
Review :
- It seems to make a mess to ~fix communication between classes, apparently. It's a pattern that makes me question whether its use is only for cases where a design is poorly structured.
- I didn't find anything useful, but maybe if I understood it better I would change my mind.

It is based on the idea of Root and Leaf, where a Root is something that has children and a Leaf is something that has no children.
In this context, it resembles the Decorator Pattern (and a bit the Strategy Pattern), since the entire Tree of a Root characterizes that Root, acting like a pseudo-wrap, reminding of the Decorator Pattern.
Although it sounds similar to a Finite State Machine, that is not actually the case, since a Root's children do not characterize 'states', but only characteristics of that Root, making it closer to the Strategy Pattern than a Finite State Machine.
Composite Pattern .
- The presenter spent most of the video discussing the 'add' and 'remove' functions of the components, discussing how this breaks the "Interface segregation principle".
- The example used in the video is quite confusing, being an example of 'to-dos in html'.
Review :
- This pattern only makes sense to use when dealing with some hierarchical organization.
- It is very similar to the Decorator, so since I didn't like the Decorator much, I didn't like this one much either.