Initial commit

Composite/add_dry_ingredients_task.rb

@@ -0,0 +1,9 @@
+class AddDryIngredientsTask < Task
+	def initialize
+		super('Add dry ingredients')
+	end
+
+	def get_time_required
+		1.0
+	end
+end

Composite/add_liquid_task.rb

@@ -0,0 +1,9 @@
+class AddLiquidTask < Task
+	def initialize
+		super('Add Liquid Task')
+	end
+
+	def get_required_time
+		2.0		# It takes 2 seconds to add liquid
+	end
+end

Composite/composite_task.rb

@@ -0,0 +1,24 @@
+class CompositeTask < Task
+	def initialize(name)
+		super(name)
+		@sub_tasks = []
+	end
+
+	def <<(task)
+		@sub_tasks << task
+	end
+
+	def remove_sub_task(task)
+		@sub_tasks.delete(task)
+	end
+
+	def [](index)
+		@sub_tasks[index]
+	end
+
+	def get_time_required
+		time = 0.0
+		@sub_tasks.each { |task| time += task.get_time_required }
+		time
+	end
+end

Composite/make_batter_task.rb

@@ -0,0 +1,15 @@
+require 'task'
+require 'add_dry_ingredients_task'
+require 'add_liquid_task'
+require 'mix_task'
+require 'composite_task'
+
+class MakeBatterTask < CompositeTask
+	def initialize
+		super('Make Batter')
+		@sub_tasks = []
+		add_sub_task(AddDryIngredientsTask.new)
+		add_sub_task(AddLiquidTask.new)
+		add_sub_task(MixTask.new)		
+	end
+end

Composite/mix_task.rb

@@ -0,0 +1,9 @@
+class MixTask < Task
+	def initialize
+		super('Mix that batter up!')
+	end
+
+	def get_time_required
+		3.0		# Mix for 3 minutes
+	end
+end

Composite/program.rb

@@ -0,0 +1,4 @@
+require 'make_batter_task'
+
+main_task = MakeBatterTask.new
+puts "The main task will take #{main_task.get_time_required} minutes"

Composite/task.rb

@@ -0,0 +1,11 @@
+class Task
+	attr_reader :name
+
+	def initialize(name)
+		@name = name
+	end
+
+	def get_time_required
+		0.0
+	end
+end

Observer/employee.rb

@@ -0,0 +1,23 @@
+require 'subject'
+
+class Employee
+	include Subject
+
+	attr_reader :name
+	attr_accessor :title, :salary
+
+	def initialize(name, title, salary)
+		super()
+		@name = name
+		@title = title
+		@salary = salary
+	end
+
+	def salary=(new_salary)
+		if salary == new_salary
+			return
+		end
+		@salary = new_salary
+		notify_observers
+	end
+end

Observer/employee_spec.rb

@@ -0,0 +1,42 @@
+require 'employee'
+
+describe Employee do	
+
+	before(:each) do
+		@employee = Employee.new('Fred', 'Crane Operator', 30000)		
+	end
+
+	context "notifies observer" do	
+
+		it "should notify its observer about a salary change" do
+			observer_mock = mock(:observer_mock)
+			observer_mock.should_receive(:update).with(@employee)	
+
+			@employee.add_observer(observer_mock)			
+			@employee.salary = 35000
+		end
+
+		it "should notify two observers about a salary change" do
+			observers = []
+
+			observers << mock()
+			observers[0].should_receive(:update).with(@employee)
+
+			observers << mock()
+			observers[1].should_receive(:update).with(@employee)
+
+			observers.each do |observer|			
+				@employee.add_observer(observer)
+			end
+
+			@employee.salary = 36000
+		end
+
+		it "should not notify if the new salary is the same as the old" do
+			observer_mock = mock(:observer_mock)			
+
+			@employee.add_observer(observer_mock)			
+			@employee.salary = 30000
+		end
+	end
+end

Observer/payroll.rb

@@ -0,0 +1,6 @@
+class Payroll
+	def update(changed_employee)
+		puts("Cut a new check for #{changed_employee.name}!")
+		puts("His salary is now #{changed_employee.salary}!")
+	end
+end

Observer/program.rb

@@ -0,0 +1,24 @@
+require 'employee'
+require 'payroll'
+require 'tax_man'
+
+=begin
+fred = Employee.new('Fred', 'Crane Operator', 30000)
+
+payroll = Payroll.new
+fred.add_observer(payroll)
+
+tax_man = TaxMan.new
+fred.add_observer(tax_man)
+
+fred.salary = 35000
+=end
+
+# Use code block as observer instead of a real class
+fred = Employee.new('Fred', 'Crane Operator', 30000)
+fred.add_observer do |changed_employee|
+	puts("Cut a new check for #{changed_employee}!")
+	puts("His salary is now #{changed_employee.salary}!")
+end
+
+fred.salary = 35000

Observer/subject.rb

@@ -0,0 +1,19 @@
+module Subject
+	def initialize
+		@observers = []
+	end
+
+	def add_observer(observer)
+		@observers << observer
+	end
+
+	def remove_observer(observer)
+		@observers.delete(observer)
+	end
+
+	def notify_observers
+		@observers.each do |observer|
+			observer.update(self)
+		end
+	end
+end

Observer/tax_man.rb

@@ -0,0 +1,5 @@
+class TaxMan
+	def update(changed_employee)
+		puts("Send #{changed_employee.name} a new tax bill!")
+	end
+end

Strategy/program.rb

@@ -0,0 +1,26 @@
+require 'report'
+
+HTML_FORMATTER = lambda do |context|
+	puts('<html>')
+	puts('   <head>')
+	puts("      <title>#{context.title}</title>")
+	puts('   </head>')
+	puts('   <body>')
+	context.text.each do |line|
+		puts("      <p>#{line}</p>")
+	end
+	puts('   </body>')
+	puts('</html>')	
+end
+
+report = Report.new &HTML_FORMATTER
+report.output_report
+
+report = Report.new do |context|
+	puts("***** #{context.title} *****")
+	context.text.each do |line|
+		puts(line)
+	end
+end
+
+report.output_report

Strategy/report.rb

@@ -0,0 +1,14 @@
+class Report
+	attr_reader :title, :text
+	attr_accessor :formatter
+
+	def initialize(&formatter)
+		@title = 'Monthly Report'
+		@text = ['Things are going', 'really, really well.']
+		@formatter = formatter
+	end
+
+	def output_report
+		@formatter.call(self)
+	end
+end

TemplateMethod/html_report.rb

@@ -0,0 +1,29 @@
+require 'report'
+
+class HTMLReport < Report
+	def output_start
+		puts('<html>')
+	end
+
+	def output_head
+		puts('   <head>')
+		puts("     <title>#{@title}</title>")
+		puts('   </head>')
+	end
+
+	def output_body_start
+		puts('   <body>')
+	end
+
+	def output_line(line)
+		puts ("        <p>#{line}</p>")
+	end
+
+	def output_body_end
+		puts('   </body>')
+	end
+
+	def output_end
+		puts('</html>')
+	end
+end

TemplateMethod/plain_text_report.rb

@@ -0,0 +1,11 @@
+class PlainTextReport < Report
+
+	def output_head
+		puts("*** #{@title} ***")		
+	end
+
+	def output_line(line)
+		puts line
+	end
+
+end

TemplateMethod/program.rb

@@ -0,0 +1,8 @@
+require 'html_report'
+require 'plain_text_report'
+
+report  = HTMLReport.new
+report.output_report
+
+report = PlainTextReport.new
+report.output_report

TemplateMethod/report.rb

@@ -0,0 +1,42 @@
+class Report
+	def initialize
+		@title = 'Monthly Report'
+		@text = [ 'Things are going', 'really, really well.']
+	end
+
+	def output_report
+		output_start
+		output_head
+		output_body_start
+		output_body
+		output_body_end
+		output_end
+	end
+
+	def output_body
+		@text.each do |line|
+			output_line(line)
+		end
+	end
+
+	def output_start
+	end
+
+	def output_head
+		raise 'Called abstract method: output_head'
+	end
+
+	def output_body_start
+	end
+
+	def output_line(line)
+		raise 'Called abstract method: output_line'
+	end
+
+	def output_body_end
+	end
+
+	def output_end
+	end
+end
+