Callbacks
Third party gems can register before and after callbacks to enhance a command.
Example
From the foo gem we have a command hello.
#!/usr/bin/env ruby
require "dry/cli"
module Foo
module CLI
module Commands
extend Dry::CLI::Registry
class Hello < Dry::CLI::Command
argument :name, required: true
def call(name:, **)
puts "hello #{name}"
end
end
end
end
end
Foo::CLI::Commands.register "hello", Foo::CLI::Commands::Hello
cli = Dry::CLI.new(Foo::CLI::Commands)
cli.call
The foo-bar gem enhances hello command with callbacks:
Foo::CLI::Commands.before("hello") { |args| puts "debug: #{args.inspect}" } # syntax 1
Foo::CLI::Commands.after "hello", &->(args) { puts "bye, #{args.fetch(:name)}" } # syntax 2
$ foo hello Anton
debug: {:name=>"Anton"}
hello Anton
bye, Anton