add requires and optional keywords for attribute definition mechanism

Author: Nils Henning

.byebug_history

@@ -1,4 +1,33 @@
 continue
+PropertyComponent.new(title: 'Test', foo: 'Foo').respond_to?(:title)
+PropertyComponent.new.respond_to?(:title)
+PropertyComponent.new.respond_to?(:title))
+continue
+self.class.requires_properties
+self.class.optional_properties
+continue
+self.class.optional_properties
+continue
+self.class.optional_properties
+self.class.requires_properties
+prop
+self.send(:options)[prop]
+self.send(:options)
+continue
+self
+self.class
+self.class.respond_to? :required_properties
+self.respond_to? :required_properties
+self.respond_to? :required_hooks
+self.respond_to? :puts
+self.responds_to? :puts
+self.defined?(:puts)
+self.defined(:puts=
+self.send(:singleton_method_undefined, :puts)
+self.send(:singleton_method_undefined)
+self.send(:singleton_method_defined?)
+self
+continue
 TestModel.destroy_all
 TestModel.first
     load "#{Rails.root}/app/models/test_model.rb"

app/concepts/matestack/ui/core/abbr/abbr.rb

@@ -1,6 +1,6 @@
 module Matestack::Ui::Core::Abbr
   class Abbr < Matestack::Ui::Core::Component::Static
-    REQUIRED_KEYS = [:title]
+    requires :title
 
     def setup
       @tag_attributes.merge!({

app/concepts/matestack/ui/core/component/base.rb

@@ -2,6 +2,7 @@ module Matestack::Ui::Core::Component
   class Base < Trailblazer::Cell
     include Matestack::Ui::Core::Cell
     include Matestack::Ui::Core::HasViewContext
+    include Matestack::Ui::Core::Properties
 
     # probably eed to remove for other tests to be green again
     include Matestack::Ui::Core::DSL
@@ -119,6 +120,7 @@ def self.views_dir
     # Special validation logic
     def validate_options
       if defined? self.class::REQUIRED_KEYS
+        ActiveSupport::Deprecation.warn("REQUIRED_KEYS is deprecated. Use `require :foo` instead.")
         self.class::REQUIRED_KEYS.each do |key|
           raise "#{self.class.name}: required key '#{key}' is missing" if options[key].nil?
         end

app/lib/matestack/ui/core/properties.rb

@@ -0,0 +1,67 @@
+module Matestack::Ui::Core::Properties
+
+  class PropertyMissingException < StandardError
+  end
+
+  class PropertyOverwritingExistingMethodException < StandardError
+  end
+
+  # prepend the initializer and add class methods
+  def self.included(base)
+    base.class_eval do
+      extend ClassMethods
+    end
+    base.send :prepend, Initializer
+  end
+  
+  # initializer calls super and creates instance methods for defined required and optional properties afterwards
+  module Initializer
+    def initialize(model=nil, options={})
+      super
+      required_hooks
+      optional_hooks
+    end
+  end
+  
+  module ClassMethods
+    # define optinoal properties for custom components with `optional :foo, :bar`
+    def optional(*properties)
+      properties.each { |property| optional_properties.push(property) }
+    end
+  
+    # define required properties for custom components with `requires :title, :foo, :bar`
+    def requires(*properties)
+      properties.each { |property| requires_properties.push(property) }
+    end
+  
+    # array of properties created from the component
+    def optional_properties
+      @component_properties ||= []
+    end
+  
+    # array of required properties from the component
+    def requires_properties
+      @requires_properties ||= []
+    end
+  end
+
+  def optional_hooks
+    self.class.optional_properties.compact.each do |prop|
+      raise PropertyOverwritingExistingMethodException, "Optional property #{prop} would overwrite already defined instance method for #{self.class}" if self.respond_to? prop
+      send(:define_singleton_method, prop) do 
+        options[prop]
+      end
+    end
+  end
+
+  def required_hooks
+    self.class.requires_properties.compact.each do |prop|
+      raise PropertyMissingException, "Required property #{prop} is missing for #{self.class}" if self.send(:options)[prop].nil?
+      raise PropertyOverwritingExistingMethodException, "Required property #{prop} would overwrite already defined instance method for #{self.class}" if self.respond_to? prop
+      send(:define_singleton_method, prop) do
+        options[prop]
+      end
+    end
+  end
+
+end

lib/matestack/ui/core/components.rb

@@ -20,6 +20,7 @@ def self.require_core_component(name)
 
   require_app_path "helpers/matestack/ui/core/application_helper"
   require_app_path "lib/matestack/ui/core/has_view_context"
+  require_app_path "lib/matestack/ui/core/properties"
 
   require_app_path "concepts/matestack/ui/core/component/base"
   require_app_path "concepts/matestack/ui/core/component/dynamic"

spec/0.8/components/abbr_spec.rb

@@ -8,7 +8,7 @@
     class ExamplePage < Matestack::Ui::Page
 
       def response
-          abbr title: 'Hypertext Markup Language', text: 'HTML'
+        abbr title: 'Hypertext Markup Language', text: 'HTML'
       end
 
     end
@@ -26,9 +26,9 @@ def response
     class ExamplePage < Matestack::Ui::Page
 
       def response
-          abbr title: 'Cascading Style Sheets' do
-            span text: 'CSS'
-          end
+        abbr title: 'Cascading Style Sheets' do
+          span text: 'CSS'
+        end
       end
 
     end

spec/0.8/components/base/properties_spec.rb

@@ -0,0 +1,119 @@
+require_relative '../../../support/utils'
+include Utils
+
+describe 'Properties Mechanism', type: :feature, js: true do
+
+  before :all do
+    class PropertyComponent < Matestack::Ui::StaticComponent
+      requires :title
+      requires :foo
+      optional :description, :bar
+      optional :text
+
+      def response
+        paragraph text: title
+        paragraph text: foo
+        paragraph text: description
+        paragraph text: bar
+        paragraph text: text
+      end
+
+      register_self_as :property_component
+    end
+  end
+
+  describe 'missing requires' do
+    it 'should raise exception if required property is missing' do
+      class ExamplePage < Matestack::Ui::Page
+        def response
+          property_component
+        end
+      end
+
+      visit '/example'
+      expect(page).to have_content(Matestack::Ui::Core::Properties::PropertyMissingException.to_s)
+      expect(page).to have_content('Required property title is missing for PropertyComponent')
+    end
+
+    it 'should raise exception if other required property is missing' do
+      class ExamplePage < Matestack::Ui::Page
+        def response
+          property_component title: 'Title'
+        end
+      end
+
+      visit '/example'
+      expect(page).to have_content(Matestack::Ui::Core::Properties::PropertyMissingException.to_s)
+      expect(page).to have_content('Required property foo is missing for PropertyComponent')
+    end
+  end
+
+  describe 'defining methods' do
+    it 'should define instance methods for required properties' do
+      class ExamplePage < Matestack::Ui::Page
+        def response
+          property_component title: 'Title', foo: 'Foo'
+        end
+      end
+      visit '/example'
+      expect(page).to have_content('Title')
+      expect(page).to have_content('Foo')
+      prop_component = PropertyComponent.new(title: 'Title', foo: 'Foo')
+      expect(prop_component.respond_to?(:title)).to be(true)
+      expect(prop_component.respond_to?(:foo)).to be(true)
+    end
+
+    it 'should define instance methods for optional properties' do
+      class ExamplePage < Matestack::Ui::Page
+        def response
+          property_component title: 'Title', foo: 'Foo', description: 'Description', bar: 'Bar'
+        end
+      end
+      visit '/example'
+      expect(page).to have_content('Description')
+      expect(page).to have_content('Bar')
+      prop_component = PropertyComponent.new(title: 'Title', foo: 'Foo')
+      expect(prop_component.respond_to?(:description)).to be(true)
+      expect(prop_component.respond_to?(:bar)).to be(true)
+    end
+  end
+
+  it 'should raise exception if required property overwrites existing method' do
+    class TempPropertyComponent < Matestack::Ui::StaticComponent
+      requires :response
+      def response
+      end
+      register_self_as :temp_property_component
+    end
+
+    class ExamplePage < Matestack::Ui::Page
+      def response
+        temp_property_component response: 'Foobar'
+      end
+    end
+
+    visit '/example'
+    expect(page).to have_content(Matestack::Ui::Core::Properties::PropertyOverwritingExistingMethodException.to_s)
+    expect(page).to have_content('Required property response would overwrite already defined instance method for TempPropertyComponent')
+  end
+
+  it 'should raise exception if optional property overwrites existing method' do
+    class TempOptionalPropertyComponent < Matestack::Ui::StaticComponent
+      optional :response
+      def response
+      end
+      register_self_as :temp_optional_property_component
+    end
+
+    class ExamplePage < Matestack::Ui::Page
+      def response
+        temp_optional_property_component response: 'Foobar'
+      end
+    end
+
+    visit '/example'
+    expect(page).to have_content(Matestack::Ui::Core::Properties::PropertyOverwritingExistingMethodException.to_s)
+    expect(page).to have_content('Optional property response would overwrite already defined instance method for TempOptionalPropertyComponent')
+  end
+
+end

spec/support/capybara.rb

@@ -36,6 +36,8 @@
 
 Capybara.javascript_driver = :headless_chrome
 
+Capybara.raise_server_errors = true
+
 # Capybara.server = :webrick
 #
 # Capybara.register_driver :selenium do |app|