Refactor survey invitations

+ Introduce Form Object
+ Set stage for Extract Validator

Author: harlow

example_app/app/controllers/invitations_controller.rb

@@ -1,57 +1,29 @@
 class InvitationsController < ApplicationController
-  EMAIL_REGEX = /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/
-
   def new
     @survey = Survey.find(params[:survey_id])
+    @survey_inviter = SurveyInviter.new
   end
 
   def create
     @survey = Survey.find(params[:survey_id])
-    if valid_recipients? && valid_message?
-      recipient_list.each do |email|
-        invitation = Invitation.create(
-          survey: @survey,
-          sender: current_user,
-          recipient_email: email,
-          status: 'pending'
-        )
-        Mailer.invitation_notification(invitation, message)
-      end
+    @survey_inviter = SurveyInviter.new(survey_inviter_params)
+
+    if @survey_inviter.invite
       redirect_to survey_path(@survey), notice: 'Invitation successfully sent'
     else
-      @recipients = recipients
-      @message = message
       render 'new'
     end
   end
 
   private
 
-  def valid_recipients?
-    invalid_recipients.empty?
-  end
-
-  def valid_message?
-    message.present?
-  end
-
-  def invalid_recipients
-    @invalid_recipients ||= recipient_list.map do |item|
-      unless item.match(EMAIL_REGEX)
-        item
-      end
-    end.compact
-  end
-
-  def recipient_list
-    @recipient_list ||= recipients.gsub(/\s+/, '').split(/[\n,;]+/)
-  end
-
-  def recipients
-    params[:invitation][:recipients]
-  end
-
-  def message
-    params[:invitation][:message]
+  def survey_inviter_params
+    params.require(:survey_inviter).permit(
+      :message,
+      :recipients
+    ).merge(
+      sender: current_user,
+      survey: @survey
+    )
   end
 end

example_app/app/models/recipient_list.rb

@@ -0,0 +1,21 @@
+class RecipientList
+  include Enumerable
+
+  def initialize(recipient_string)
+    @recipient_string = recipient_string
+  end
+
+  def each(&block)
+    recipients.each(&block)
+  end
+
+  def to_s
+    @recipient_string
+  end
+
+  private
+
+  def recipients
+    @recipient_string.to_s.gsub(/\s+/, '').split(/[\n,;]+/)
+  end
+end

example_app/app/models/survey_inviter.rb

@@ -0,0 +1,53 @@
+class SurveyInviter
+  include ActiveModel::Model
+  attr_accessor :recipients, :message, :sender, :survey
+  EMAIL_REGEX = /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i
+
+  validates :message, presence: true
+  validates :recipients, presence: true
+  validates :sender, presence: true
+  validates :survey, presence: true
+
+  validate :recipient_email_validator
+
+  def recipients=(recipients)
+    unless recipients.blank?
+      @recipients = RecipientList.new(recipients)
+    end
+  end
+
+  def invite
+    if valid?
+      deliver_invitations
+    end
+  end
+
+  private
+
+  def create_invitations
+    recipients.map do |recipient_email|
+      Invitation.create!(
+        survey: survey,
+        sender: sender,
+        recipient_email: recipient_email,
+        status: 'pending'
+      )
+    end
+  end
+
+  def deliver_invitations
+    create_invitations.each do |invitation|
+      Mailer.invitation_notification(invitation, message).deliver
+    end
+  end
+
+  def recipient_email_validator
+    return if recipients.blank?
+
+    recipients.each do |recipient|
+      unless recipient.match(EMAIL_REGEX)
+        errors.add(:recipients, "#{recipient} is not a valid email address.")
+      end
+    end
+  end
+end

example_app/app/views/invitations/new.html.erb

@@ -1,14 +1,6 @@
-<%= simple_form_for :invitation, url: survey_invitations_path(@survey) do |f| %>
-  <%= f.input :message, as: :text, input_html: { value: @message } %>
-  <% if @invlid_message %>
-    <div class="error">Please provide a message</div>
-  <% end %>
-  <%= f.input :recipients, as: :text, input_html: { value: @recipients } %>
-  <% if @invalid_recipients %>
-    <div class="error">
-      Invalid email addresses: 
-      <%= @invalid_recipients.join(', ') %>
-    </div>
-  <% end %>
+<%= simple_form_for @survey_inviter, 
+  url: survey_invitations_path(@survey) do |f| %>
+  <%= f.input :message, as: :text %>
+  <%= f.input :recipients, as: :text %>
   <%= f.button :submit, value: 'Invite' %>
 <% end %>

example_app/config/application.rb

@@ -22,7 +22,7 @@ class Application < Rails::Application
     # -- all .rb files in that directory are automatically loaded.
 
     # Custom directories with classes and modules you want to be autoloadable.
-    # config.autoload_paths += %W(#{config.root}/extras)
+    config.autoload_paths += %W(#{config.root}/lib)
 
     # Only load the plugins named here, in the order given (default is alphabetical).
     # :all can be used as a placeholder for all plugins not explicitly named.

example_app/lib/active_model/model.rb

@@ -0,0 +1,97 @@
+module ActiveModel
+
+  # == Active \Model Basic \Model
+  #
+  # Includes the required interface for an object to interact with
+  # <tt>ActionPack</tt>, using different <tt>ActiveModel</tt> modules.
+  # It includes model name introspections, conversions, translations and
+  # validations. Besides that, it allows you to initialize the object with a
+  # hash of attributes, pretty much like <tt>ActiveRecord</tt> does.
+  #
+  # A minimal implementation could be:
+  #
+  #   class Person
+  #     include ActiveModel::Model
+  #     attr_accessor :name, :age
+  #   end
+  #
+  #   person = Person.new(name: 'bob', age: '18')
+  #   person.name # => 'bob'
+  #   person.age  # => 18
+  #
+  # Note that, by default, <tt>ActiveModel::Model</tt> implements <tt>persisted?</tt>
+  # to return +false+, which is the most common case. You may want to override
+  # it in your class to simulate a different scenario:
+  #
+  #   class Person
+  #     include ActiveModel::Model
+  #     attr_accessor :id, :name
+  #
+  #     def persisted?
+  #       self.id == 1
+  #     end
+  #   end
+  #
+  #   person = Person.new(id: 1, name: 'bob')
+  #   person.persisted? # => true
+  #
+  # Also, if for some reason you need to run code on <tt>initialize</tt>, make
+  # sure you call +super+ if you want the attributes hash initialization to
+  # happen.
+  #
+  #   class Person
+  #     include ActiveModel::Model
+  #     attr_accessor :id, :name, :omg
+  #
+  #     def initialize(attributes={})
+  #       super
+  #       @omg ||= true
+  #     end
+  #   end
+  #
+  #   person = Person.new(id: 1, name: 'bob')
+  #   person.omg # => true
+  #
+  # For more detailed information on other functionalities available, please
+  # refer to the specific modules included in <tt>ActiveModel::Model</tt>
+  # (see below).
+  module Model
+    def self.included(base) #:nodoc:
+      base.class_eval do
+        extend  ActiveModel::Naming
+        extend  ActiveModel::Translation
+        include ActiveModel::Validations
+        include ActiveModel::Conversion
+      end
+    end
+
+    # Initializes a new model with the given +params+.
+    #
+    #   class Person
+    #     include ActiveModel::Model
+    #     attr_accessor :name, :age
+    #   end
+    #
+    #   person = Person.new(name: 'bob', age: '18')
+    #   person.name # => "bob"
+    #   person.age  # => 18
+    def initialize(params={})
+      params.each do |attr, value|
+        self.public_send("#{attr}=", value)
+      end if params
+    end
+
+    # Indicates if the model is persisted. Default is +false+.
+    #
+    #  class Person
+    #    include ActiveModel::Model
+    #    attr_accessor :id, :name
+    #  end
+    #
+    #  person = Person.new(id: 1, name: 'bob')
+    #  person.persisted? # => false
+    def persisted?
+      false
+    end
+  end
+end

example_app/spec/models/recipient_list_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+describe '#map' do
+  it 'parses recipients separated by commas' do
+    recipient_list('one@example.com, two@example.com').should 
+      eq ['one@example.com', 'two@example.com']
+  end
+
+  it 'parses recipients separated by newlines' do
+    recipient_list("one@example.com\ntwo@example.com").should 
+      eq ['one@example.com', 'two@example.com']
+  end
+
+  it 'parses recipients separated by semi-colons' do
+    recipient_list("one@example.com; two@example.com").should 
+      eq ['one@example.com', 'two@example.com']
+  end
+
+  def recipient_list(string)
+    RecipientList.new(string).map(&:to_s)
+  end
+end
+
+describe RecipientList, '#to_s' do
+  it 'returns the original string' do
+    RecipientList.new('some string').to_s.should eq 'some string'
+  end
+end

example_app/spec/models/survey_inviter_spec.rb

@@ -0,0 +1,36 @@
+require 'spec_helper'
+
+describe SurveyInviter, 'Validations' do
+  it { should validate_presence_of(:message) }
+  it { should validate_presence_of(:recipients) }
+  it { should validate_presence_of(:sender) }
+  it { should validate_presence_of(:survey) }
+end
+
+describe SurveyInviter, '#invite' do
+  it 'invites a valid recipient' do
+    SurveyInviter.new(valid_params).invite
+
+    Invitation.count.should eq 1
+    ActionMailer::Base.deliveries.count.should eq 1
+  end
+
+  it 'returns false for an invalid recipient' do
+    SurveyInviter.new(invalid_params).invite.should be_false
+  end
+
+  def valid_params
+    {
+      survey: build(:survey),
+      sender: build(:sender),
+      message: 'Take my survey!',
+      recipients: 'valid@example.com'
+    }
+  end
+
+  def invalid_params
+    valid_params.merge(
+      recipients: 'invalid_email'
+    )
+  end
+end

example_app/spec/spec_helper.rb

@@ -16,4 +16,5 @@
   config.mock_framework = :mocha
   config.include FactoryGirl::Syntax::Methods
   config.include Features, type: :feature
+  config.before(:each) { ActionMailer::Base.deliveries.clear }
 end