The Builder is a design pattern designed to provide a flexible solution to various object creation problems in object-oriented programming. The intent of the Builder design pattern is to separate the construction of a complex object from its representation. It is one of the Gang of Four design patterns. This library was created based on the book Design Patterns in Ruby and the repository.
Execute:
$ bundle install
require './lib/design/patterns/builder'
builder = Design::Patterns::Builder::ComputerBuilder.new
builder.turbo
builder.display(:lcd)
builder.add_cd
builder.add_dvd(true)
builder.add_hard_disk(100_000)
# manufacture 10 computers using the builder
computers = []
10.times { computers << builder.computer.clone }
computers.each { |computer| puts computer }
# computer must have at least 250 MB of memory
builder = Design::Patterns::Builder::ComputerBuilder.new
builder.memory_size(249)
begin
builder.computer
rescue Exception => e
puts e.message
end
# computer must have at most 4 drives
builder = Design::Patterns::Builder::ComputerBuilder.new
builder.add_cd
builder.add_dvd
builder.add_hard_disk(1000)
builder.add_cd
builder.add_dvd
begin
builder.computer
rescue Exception => e
puts e.message
end
# use magic method to rapidly build a computer
puts 'Computer built with magic method builder'
builder = Design::Patterns::Builder::ComputerBuilder.new
builder.add_cd_and_dvd_and_harddisk_and_turbo
computer = builder.computer
puts "CPU: #{computer.motherboard.cpu.class}"
computer.drives.each { |drive| puts "Drive: #{drive.type}" }
After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/scalone/design-patterns-builder. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
The gem is available as open source under the terms of the MIT License.
Everyone interacting in the Design::Patterns::Builder project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.