A simple command-pattern helper gem for Ruby.
Add this line to your application's Gemfile:
gem 'mandate'And then execute:
$ bundle
Or install it yourself as:
$ gem install mandate
class Multiplies
include Mandate
initialize_with :number_1, :number_2
def call
do_the_maths
end
# Memoize any method by putting the keyword before it.
memoize
def do_the_maths
sleep(10)
number_1 * number_2
end
end
# This calls initializer and then call with the params
Multiplies.(20, 3)
# => 60The initialize_with method creates an initializer and private attr_readers for the specified variables.
For example initialize_with :foo, :bar is the equivalent of:
def initialize(foo, bar)
@foo = foo
@bar = bar
end
private
attr_reader :foo, :barSometimes it is helpful for the class to return on_success/on_failure callbacks rather than just the resulting value.
This can be achieved by including the Mandate::Callbacks module as follows:
class Sumer
include Mandate
include Mandate::Callbacks
initialize_with :num1, :num2
def call
abort!("num1 must be an Integer") unless num1.is_a?(Integer)
abort!("num2 must be an Integer") unless num2.is_a?(Integer)
num1 + num2
end
end
res = Sumer.(1,2)
res.on_success { |result| p result } # puts 3
res.on_failure { |errors| p errors } # Noop
res.succeeded? # true
res.result # 3
res.errors # []
res = Sumer.("1","2")
res.on_success { |result| p result } # Noop
res.on_failure { |errors| p errors } # puts ["num1 must be an Integer"]
res = Sumer.("1","2")
res.on_failure { |errors| p errors } # puts ["num1 must be an Integer", "num2 must be an Integer"]
res.errors # ["num1 must be an Integer", "num2 must be an Integer"]It is also possible to chain methods, for example:
Sumer.(1,2).
on_success { |result| p result }.
on_failure { |errors| p errors }The succeeded? method is also aliased as success?.
After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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/iHiD/mandate.