builder

The Builder pattern belongs to a group of patterns, the existence of which is not particularly clear to me, I note the obvious redundancy of this. Belongs to the group of generative design patterns. It is used to implement a simple interface for creating complex objects.

Applicability

Simplification of the interface. It can make it easier to create an object in constructors with a large number of arguments, objectively improving the readability of the code.

Example in C++ without a builder:

auto weapon = new Weapon(“Claws”);
monster->weapon = weapon;
auto health = new MonsterHealth(100);
monster->health = health;

Пример со строителем на C++:

                  .addWeapon(“Claws”)
                  .addHealth(100)
                  .build();

Однако в языках поддерживающих именованные аргументы (named arguments), необходимость использовать именно для этого случая отпадает.

Пример на Swift с использованием named arguments:

let monster = Monster(weapon: “Claws”, health: 100)

Immutability. Using the builder, you can ensure the encapsulation of the created object until the final assembly stage. Here you need to think carefully whether the use of the pattern will save you from the high dynamics of the environment in which you work, perhaps the use of the pattern will not give anything, due to the simple lack of a culture of using encapsulation in the development team.

Interaction with components at different stages of object creation. Also, using the pattern, it is possible to provide step-by-step creation of an object when interacting with other components of the system. Most likely, this is very useful (?)

Criticism

Of course, you need to *carefully* think about whether it is worth setting up widespread use of the pattern in your project. Languages with modern syntax and advanced IDEs eliminate the need to use the Builder, in terms of improving code readability (see the point about named arguments)
Was this pattern necessary in 1994, when the GoF book was published? Most likely yes, but judging by the open source code base of those years, few people used it.

Sources

https://refactoring.guru/ru/design-patterns/builder

Tag Archives: builder

Pattern Builder

Applicability

Criticism

Sources