Trivial dependency resolver for Ruby, using introspection
Hinge is a trivial dependency resolver. With Hinge, you can write down object dependencies
in a linear fashion to have a simple overview of them.
class Deps
# This method implements building a logger. It has no dependencies.
def build_logger
Logger.new($stdout)
end
# This method builds an instance of the `Processor` class you want to use,
# initialized with the logger from the previous method.
# This matching is done by the name of the parameter!
def build_processor(logger)
Processor.new(logger)
end
# Named parameters can be used as well!
def build_runner(logger:)
Runner.new(logger)
end
end
deps = Deps.new
resolver = Hinge.resolver(deps)
processor = resolver.resolve(:processor)
resolver.resolve(:processor).equal?(processor) # => true (the same object is returned as last time)
And that’s all!
Varying dependencies depending on the environment can now easily be handled in a number of ways,
ranging from if/else
or case
constructs to inheritance or overriding methods of Deps
.
Add this line to your application’s Gemfile:
gem 'hinge'
And then execute:
$ bundle
Or install it yourself as:
$ gem install hinge
Tests are written in RSpec.
Bug reports and pull requests are welcome on GitHub at https://github.com/schnittchen/hinge.