Sequential Transitions

what are sequential transitions:

Sequential transitions, where each state can transition to the previous and/or next state is a common implementation within both form and service objects. The make_sequential option is included to simplify the configuration.

In this example, both attributes :status and status_test have the same transitions.

class Post < ActiveRecord::Base
  include StateGate

  state_gate :status do
    state :draft,     transitions_to: :pending
    state :pending,   transitions_to: [:draft, :published]
    state :published, transitions_to: [:pending, :archived]
    state :archived,  transitions_to: :published
  end

  state_gate :status_test do
    state :draft
    state :pending
    state :published
    state :archived

    make_sequential
  end
end


Post.status_transitions      #=> { draft:     [:pending],
                             #=>   pending:   [:draft, :published],
                             #=>   published: [:pending, :archived],
                             #=>   archived:  [:published] }


Post.status_Test_transitions #=> { draft:     [:pending],
                             #=>   pending:   [:draft, :published],
                             #=>   published: [:pending, :archived],
                             #=>   archived:  [:published] }

one-way only:

The :one_way parameter will restrict transition to 'next state' only.

class Post < ActiveRecord::Base
  include StateGate

  state_gate :status do
    state :draft,     transitions_to: :pending
    state :pending,   transitions_to: [:draft, :published]
    state :published, transitions_to: [:pending, :archived]
    state :archived,  transitions_to: :published

    make_sequential :one_way
  end
end


Post.status_transitions      #=> { draft:     [:pending],
                             #=>   pending:   [:published],
                             #=>   published: [:archived],
                             #=>   archived:  [] }

closing the loop:

The :loop parameter will allow the first and last states to transition to each other, taking into account the :one_way option.

class Post < ActiveRecord::Base
  include StateGate

  state_gate :status do
    state :draft
    state :pending
    state :published
    state :archived

    make_sequential :loop
  end


  state_gate :status_test do
    state :draft
    state :pending
    state :published
    state :archived

    make_sequential :one_way, :loop
  end
end


Post.status_transitions      #=> { draft:     [:archived, :pending],
                             #=>   pending:   [:draft, :published],
                             #=>   published: [:pending, :archived],
                             #=>   archived:  [:published, :draft] }


Post.status_Test_transitions #=> { draft:     [:pending],
                             #=>   pending:   [:published],
                             #=>   published: [:archived],
                             #=>   archived:  [:draft] }