active-interaction-coder

# ActiveInteraction Coder Typed business operations as the structured alternative to service objects. ## Why ActiveInteraction Over Service Objects | Service Objects | ActiveInteraction | |-----------------|-------------------| | No standard interface | Consistent `.run` / `.run!` | | Manual type checking | Built-in type declarations | | Manual validation | Standard Rails validations | | Hard to compose | Native composition | | Verbose boilerplate | Clean, self-documenting | ## Setup ```ruby # Gemfile gem "active_interaction", "~> 5.3" ``` ## Simple Interaction ```ruby # app/interactions/users/create.rb module Users class Create < ActiveInteraction::Base # Typed inputs string :email string :name string :password, default: nil # Validations validates :email, presence: true, format: { with: URI::MailTo::EMAIL_REGEXP } validates :name, presence: true # Main logic def execute user = User.create!( email: email, name: name, password: password || SecureRandom.alphanumeric(32) ) UserMailer.welcome(user).deliver_later user # Return value becomes outcome.result end end end ``` ## Running Interactions ```ruby # In controller def create outcome = Users::Create.run( email: params[:email], name: params[:name] ) if outcome.valid? redirect_to outcome.result, notice: "User created" else @errors = outcome.errors render :new, status: :unprocessable_entity end end # With bang method (raises on error) user = Users::Create.run!(email: "user@example.com", name: "John") ``` ## Input Types ```ruby class MyInteraction < ActiveInteraction::Base # Primitives string :name integer :age float :price boolean :active symbol :status # Date/Time date :birthday time :created_at date_time :scheduled_at # Complex types array :tags hash :metadata # Model instances object :user, class: User # Typed arrays array :emails, default: [] do string end # Optional with default string :optional_field, default: nil integer :count, default: 0 end ``` ## Composing Interactions ```ruby module Users class Register < ActiveInteraction::Base string :email, :name, :password def execute # Compose calls another interaction user = compose(Users::Create, email: email, name: name, password: password ) # Errors automatically merged if nested fails compose(Users::SendWelcomeEmail, user: user) user end end end ``` ## Controller Pattern ```ruby class ArticlesController < ApplicationController def create outcome = Articles::Create.run( title: params[:article][:title], body: params[:article][:body], author: current_user ) if outcome.valid? redirect_to article_path(outcome.result), notice: "Article created" else @article = Article.new(article_params) @article.errors.merge!(outcome.errors) render :new, status: :unprocessable_entity end end end ``` ## Testing Interactions ```ruby RSpec.describe Users::Create do let(:valid_params) { { email: "user@example.com", name: "John" } } it "creates user with valid inputs" do expect { described_class.run(valid_params) } .to change(User, :count).by(1) end it "returns valid outcome" do outcome = described_class.run(valid_params) expect(outcome).to be_valid expect(outcome.result).to be_a(User) end it "validates email format" do outcome = described_class.run(valid_params.merge(email: "invalid")) expect(outcome).not_to be_valid expect(outcome.errors[:email]).to be_present end end ``` ## Advanced Patterns For composition, error handling, and custom types see: - `references/active-interaction.md`