What is a result?

  • A result is the data structure every Convenient Service service returns. It is inspired by JSend, but not JSend-compatible. It provides a unified way to check the outcome of an operation and access its data, message, and code.

    class FindUser
  include ConvenientService::Standard::Config

  attr_reader :id

  def initialize(id:)
    @id = id
  end

  def result
    return error("Id is `nil`") if id.nil?

    users = {1 => {name: "John"}}

    return failure("User with id `#{id}` does not exist") unless users.key?(id)

    success(user: users[id])
  end
end

result = FindUser.result(id: 1)

result.class
# => FindUser::Result

result.status.to_sym
# => :success

  • Status checks: success?, failure?, error?, not_success?, not_failure?, not_error?.

  • Attributes: status, data, message, code, service (the service instance that produced the result), original_service (for results returned via steps, the step's own service - not the organizer).

    result.success?
# => true

result.data[:user]
# => {name: "John"}

  • Accessing data, message, or code before checking the result's status raises an error.

    result = FindUser.result(id: 1)

result.data
# raises ConvenientService::Service::Plugins::HasJSendResult::Entities::Result::Plugins::RaisesOnNotCheckedResultStatus::Exceptions::StatusIsNotChecked

  • ud, um, and uc are debugger-friendly shortcuts for unsafe_data, unsafe_message, and unsafe_code - they skip the status check, which is convenient when inspecting a result in a debugger session.

    result.ud
# => <FindUser::Result::Data user: {name: "John"}>

See also

Sources