What is an organizer service?

  • An organizer service composes other services (or methods) via steps. If any step is not successful, the pipeline stops and that step's result is returned as the whole service's result.

    class AssertFileExists
  include ConvenientService::Standard::Config

  attr_reader :path

  def initialize(path:)
    @path = path
  end

  def result
    return failure("File does not exist at path `#{path}`") unless File.exist?(path)

    success
  end
end

class AssertFileNotEmpty
  include ConvenientService::Standard::Config

  attr_reader :path

  def initialize(path:)
    @path = path
  end

  def result
    return failure("File is empty at path `#{path}`") if File.empty?(path)

    success
  end
end

class ReadFileContent
  include ConvenientService::Standard::Config

  step AssertFileExists, in: :path
  step AssertFileNotEmpty, in: :path
  step :result, in: :path, out: :content

  attr_reader :path

  def initialize(path:)
    @path = path
  end

  def result
    success(content: File.read(path))
  end
end

  • If AssertFileExists fails, the pipeline stops there - AssertFileNotEmpty and step :result never run.

    result = ReadFileContent.result(path: "/tmp/non_existent.txt")

result.success?
# => false

result.original_service.class
# => AssertFileExists

  • The same applies to AssertFileNotEmpty - when it fails, step :result is skipped.

    File.write("/tmp/empty.txt", "")

result = ReadFileContent.result(path: "/tmp/empty.txt")

result.success?
# => false

result.original_service.class
# => AssertFileNotEmpty

  • When every step succeeds, ReadFileContent returns the final step :result result.

    File.write("/tmp/hello.txt", "Hello!")

result = ReadFileContent.result(path: "/tmp/hello.txt")

result.success?
# => true

result.data[:content]
# => "Hello!"

  • An organizer service is contrasted with a regular service, which implements result directly instead of composing steps.

See also

Sources