Flexible consignment of arguments to lambdas using scopes.
Add this line to your application's Gemfile:
gem 'flexcon'And then execute:
$ bundle
Or install it yourself as:
$ gem install flexcon
And then execute:
$ bundle
Or install it yourself as:
$ gem install Flexcon
Given a scope which could be an array, a hash, an object, or a proc - dispatch attributes of the scope into lambdas:
array_scope = ['John', 'Doe', 'Acme Corporation']
hash_scope = { last_name: 'Doe', first_name: 'John', company: 'Acme Corporation' }
object_scope = OpenStruct.new(hash_scope)
full_name = lambda do |first_name, last_name|
"#{first_name} #{last_name}"
end
employee = lambda do |first_name, last_name, company|
"#{first_name} #{last_name} of #{company}"
end
# The following returns 'John Doe'
Flexcon.dispatch(array_scope, full_name)
Flexcon.dispatch(hash_scope, full_name)
Flexcon.dispatch(object_scope, full_name)
# The following returns 'John Doe of Acme Corporation'
Flexcon.dispatch(array_scope, employee)
Flexcon.dispatch(hash_scope, employee)
Flexcon.dispatch(object_scope, employee)
# The following returns "['user', 'student', 'university']"
proc_scope = -> () do
{
models: [:user, :student, :university],
api: -> (params) do
params.to_json
end
}
end
api_wrapper = lambda do |api, models|
api.call(models)
end
Flexcon.dispatch(proc_scope, api_wrapper)If the method signature needed for certain functions are difficult to predict, instead of enforcing a single method signature, allow methods to ask for what they need from a scope.
class Operation
def initialize
@steps = []
@named = {}
end
def step(name, &block)
@steps << block
@named[name] = block
end
def call(scope)
@steps.each do |step|
Flexcon.dispatch(scope, step)
end
end
end
class Scope
attr_accessor :params, :models
def initialize(params={})
self.params = params
self.models = {}
end
end
op = Operation.new
op.step :find_or_init_user do |params, models|
user = User.find_by(email: params[:user][:email])
user ||= User.new(params[:user])
models[:user] = user
end
op.step :find_or_init_student do |params, models|
student = Student.find_or_initialize_by(user: models[:user], university_id: params[:university_id])
student.assign_attributes(params[:student])
models[:student] = student
end
op.step :save_user do |models|
models[:user].save!
end
op.step :save_student do |models|
models[:student].save!
end
op.call(Scope.new({}))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/rcpedro/flexcon.