Merge pull request #4 from jdickey/create-the-thing

Create the Thing entered in the new-thing form. Widgets and objects and forms; oh my!

Gemfile.lock

@@ -43,7 +43,7 @@ GEM
     ansi (1.5.0)
     arel (6.0.3)
     arrayfields (4.9.2)
-    ast (2.1.0)
+    ast (2.2.0)
     astrolabe (1.3.1)
       parser (~> 2.2)
     awesome_print (1.6.1)
@@ -84,16 +84,17 @@ GEM
     coderay (1.1.0)
     coercible (1.0.0)
       descendants_tracker (~> 0.0.1)
-    coffee-rails (4.1.0)
+    coffee-rails (4.1.1)
       coffee-script (>= 2.2.0)
-      railties (>= 4.0.0, < 5.0)
+      railties (>= 4.0.0, < 5.1.x)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.10.0)
     concord (0.1.5)
       adamantium (~> 0.2.0)
       equalizer (~> 0.0.9)
+    concurrent-ruby (1.0.0)
     coveralls (0.8.10)
       json (~> 1.8)
       rest-client (>= 1.6.8, < 2)
@@ -157,11 +158,11 @@ GEM
       nokogiri (>= 1.5.9)
     mail (2.6.3)
       mime-types (>= 1.16, < 3)
-    main (6.1.0)
+    main (6.2.0)
       arrayfields (>= 4.7.4)
       chronic (>= 0.6.2)
       fattr (>= 2.2.0)
-      map (>= 5.1.0)
+      map (>= 6.1.0)
     map (6.5.5)
     memoizable (0.4.2)
       thread_safe (~> 0.3, >= 0.3.1)
@@ -194,7 +195,7 @@ GEM
       ruby-progressbar
     multi_json (1.11.2)
     netrc (0.11.0)
-    nokogiri (1.6.7)
+    nokogiri (1.6.7.1)
       mini_portile2 (~> 2.0.0.rc2)
     ox (2.2.2)
     parser (2.2.3.0)
@@ -242,8 +243,8 @@ GEM
       rails-deprecated_sanitizer (>= 1.0.1)
     rails-html-sanitizer (1.0.2)
       loofah (~> 2.0)
-    rails_semantic_logger (1.7.0)
-      semantic_logger (>= 2.5.0)
+    rails_semantic_logger (1.8.0)
+      semantic_logger (~> 2.20)
     railties (4.2.5)
       actionpack (= 4.2.5)
       activesupport (= 4.2.5)
@@ -276,7 +277,7 @@ GEM
     ruby_parser (3.7.2)
       sexp_processor (~> 4.1)
     rubyzip (1.1.7)
-    sass (3.4.19)
+    sass (3.4.20)
     sass-rails (5.0.4)
       railties (>= 4.0.0, < 5.0)
       sass (~> 3.1)
@@ -288,29 +289,28 @@ GEM
       multi_json (~> 1.0)
       rubyzip (~> 1.0)
       websocket (~> 1.0)
-    semantic_logger (2.18.0)
-      sync_attr (~> 2.0)
-      thread_safe (~> 0.1)
+    semantic_logger (2.21.0)
+      concurrent-ruby (~> 1.0)
     sequel (4.29.0)
     sequel-rails (0.9.11)
       actionpack (>= 3.2.0)
       activemodel
       railties (>= 3.2.0)
       sequel (>= 3.28, < 5.0)
     sexp_processor (4.6.0)
-    simplecov (0.11.0)
+    simplecov (0.11.1)
       docile (~> 1.1.0)
       json (~> 1.8)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.0)
     slop (3.6.0)
-    sprockets (3.4.1)
+    sprockets (3.5.2)
+      concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (2.3.3)
-      actionpack (>= 3.0)
-      activesupport (>= 3.0)
-      sprockets (>= 2.8, < 4.0)
-    sync_attr (2.0.0)
+    sprockets-rails (3.0.0)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
     term-ansicolor (1.3.2)
       tins (~> 1.0)
     thin (1.6.4)
@@ -401,4 +401,4 @@ DEPENDENCIES
   web-console (~> 2.0)
 
 BUNDLED WITH
-   1.10.6
+   1.11.2

app/controllers/things_controller.rb

@@ -3,26 +3,23 @@
 
 # ThingsController is our  one and only demo controller.
 class ThingsController < ApplicationController
-  include SemanticLogger::Loggable
+  # include SemanticLogger::Loggable
 
   def index
-    index_responder { |things| @things = things }
-    self
+    respond_with(IndexResponder) { |things| @things = things }
   end
 
   def new
-    new_responder { |thing| @thing = thing }
-    logger.debug 'Returning from #new', @thing
-    self
+    respond_with(NewResponder) { |thing| @thing = thing }
   end
 
-  private
-
-  def index_responder
-    IndexResponder.new(self).call(params) { |things| yield things }
+  def create
+    respond_with(CreateResponder) { |thing| @thing = thing }
   end
 
-  def new_responder
-    NewResponder.new(self).call(params) { |thing| yield thing }
+  private
+
+  def respond_with(responder, &_block)
+    responder.new(self).call(params) { |product| yield product }
   end
 end

app/controllers/things_controller/create_responder.rb

@@ -0,0 +1,60 @@
+
+require 'create_thing'
+
+# ThingsController is our  one and only demo controller.
+class ThingsController < ApplicationController
+  # Encapsulates all logic involved in create action, successful or otherwise.
+  class CreateResponder
+    # include SemanticLogger::Loggable
+
+    def initialize(controller)
+      @controller = controller
+      self
+    end
+
+    def call(params, &_block)
+      create_and_save_thing params
+      yield @thing
+      handle_result
+    end
+
+    private
+
+    attr_reader :controller, :thing
+
+    def create_thing(params)
+      @thing = FormObjects::CreateThing.new params['thing']
+      self
+    end
+
+    def create_and_save_thing(params)
+      create_thing params
+      @thing.save if @thing.valid?
+      self
+    end
+
+    def handle_result
+      return handle_success if @thing.valid?
+      handle_failure
+    end
+
+    def handle_failure
+      # Controller's @thing should already be set by this point per yield
+      controller.render 'new'
+      self
+    end
+
+    def handle_success
+      controller.redirect_to success_redirect_target, success_flash
+    end
+
+    def success_flash
+      message = ['Added your new "', '" Thing!'].join thing.name
+      { flash: { success: message } }
+    end
+
+    def success_redirect_target
+      controller.root_path
+    end
+  end # class ThingsController::CreateResponder
+end # class ThingsController

app/form_objects/create_thing.rb

@@ -0,0 +1,66 @@
+
+require 'virtus'
+
+require_relative 'create_thing/uniqueness'
+require_relative 'create_thing/validation_error'
+
+module FormObjects
+  # All the logic needed to create a new Thing record based on input parameters.
+  class CreateThing
+    include SemanticLogger::Loggable
+    include Virtus.model
+    include ActiveModel::Validations
+
+    attribute :name, String
+    attribute :initial_quantity, Integer
+    attribute :description, String
+
+    validates :name, presence: true
+    validates :initial_quantity, numericality: {
+      greater_than_or_equal_to: 1,
+      only_integer: true
+    }
+    validates :description, presence: true, allow_blank: false
+    validate :unique?
+
+    def new?
+      !Thing.find(name: name)
+    end
+
+    def save
+      validate_before_save
+      new_record.save
+      self
+    end
+
+    private
+
+    def add_uniquness_failure_error
+      errors.add :name, 'has already been added. Please enter a new one.'
+    end
+
+    def can_save?
+      valid? && unique?
+    end
+
+    def new_record
+      Thing.new attributes
+    end
+
+    # Since we don't keep track of record IDs in this class, we have to wing it
+    # using attributes.
+    def unique?
+      return true if Uniqueness.new(attributes).unique?
+      add_uniquness_failure_error
+      false
+    end
+
+    def validate_before_save
+      fail validation_error unless can_save?
+    end
+
+    def validation_error
+      ValidationError.new invalid_attributes: attributes, errors_found: errors
+    end
+  end # class FormObjects::CreateThing
+end

app/form_objects/create_thing/uniqueness.rb

@@ -0,0 +1,38 @@
+
+module FormObjects
+  # All the logic needed to create a new Thing record based on input parameters.
+  class CreateThing
+    # Encapsulates testing whether a set of ORM attributes are "unique". This is
+    # true if either of the following conditions is true:
+    # 1. No ORM instance exists whose name field has the same name, OR
+    # 2. An ORM instance exists with ALL fields matching the attributes, whereby
+    #    it is presumed to be the "same" record. We really should ensure that a
+    #    database constraint is set to force that.
+    class Uniqueness
+      def initialize(attributes)
+        @attributes = attributes
+        self
+      end
+
+      def unique?
+        !existing || same_instance?
+      end
+
+      private
+
+      attr_reader :attributes
+
+      def existing
+        @existing ||= Thing.find(name: attributes[:name])
+      end
+
+      def existing_attributes
+        existing.values.except(:id)
+      end
+
+      def same_instance?
+        attributes == existing_attributes
+      end
+    end # class FormObjects::CreateThing::Uniqueness
+  end # class FormObjects::CreateThing
+end

app/form_objects/create_thing/validation_error.rb

@@ -0,0 +1,27 @@
+
+module FormObjects
+  # All the logic needed to create a new Thing record based on input parameters.
+  class CreateThing
+    # Error to be raised when validation of a CreateThing instance fails.
+    class ValidationError < RuntimeError
+      include Virtus.model(strict: true)
+
+      def initialize(invalid_attributes:, errors_found:)
+        @invalid_attributes = invalid_attributes
+        @errors_found = errors_found
+        super()
+      end
+
+      def message
+        ['Validation of Thing attributes failed. Invalid attributes:',
+         "#{invalid_attributes}, errors found: #{errors_found.full_messages}"
+        ].join ' '
+      end
+
+      values do
+        attribute :invalid_attributes, Array[String]
+        attribute :errors_found, ActiveModel::Errors
+      end
+    end # class FormObjects::CreateThing::ValidationError
+  end # class FormObjects::CreateThing
+end

app/views/things/index.rb

@@ -1,9 +1,14 @@
 
+require File.expand_path 'app/views/things/shared/flashes', Rails.root
+
 # Class encapsulating all page-specific view code for `things/index`.
 class Views::Things::Index < Views::Base
   needs :things, flash: {}
 
+  include Views::Things::Shared
+
   def content
+    widget Flashes, flashes: flash
     non_detail_widgets
     detail_table
   end
@@ -18,22 +23,8 @@ def detail_table
     table_widget { detail_lines }
   end
 
-  def each_flash
-    flash_as_hash.each { |type, message| yield type, message }
-  end
-
-  def flash_as_hash
-    flash.to_h.symbolize_keys
-  end
-
-  def flash_content
-    each_flash do |type, message|
-      widget FlashAlert, type: type, message: message
-    end
-  end
-
   def non_detail_widgets
-    messages = [:title_content, :flash_content, :page_header, :add_thing_button]
+    messages = [:title_content, :page_header, :add_thing_button]
     messages.each { |message| send message }
   end