如何將父任務的參數傳遞給Rake中的子任務？

Question

我在寫一個Rake腳本，它包含帶參數的任務。我想出瞭如何傳遞參數以及如何使任務依賴於其他任務。

task :parent, [:parent_argument1, :parent_argument2, :parent_argument3] => [:child1, :child2] do 
    # Perform Parent Task Functionalities 
end 

task :child1, [:child1_argument1, :child1_argument2] do |t, args| 
    # Perform Child1 Task Functionalities 
end 

task :child2, [:child2_argument1, :child2_argument2] do |t, args| 
    # Perform Child2 Task Functionalities 
end 

• 我可以傳遞參數從父任務的子任務？
• 有沒有辦法讓孩子的任務爲私人，所以他們不能獨立調用？

Answer 1

我實際上可以想到在Rake任務之間傳遞參數的三種方法。

1. 使用rake的內置的論據支持：

   # accepts argument :one and depends on the :second task. 
   task :first, [:one] => :second do |t, args| 
       puts args.inspect # => '{ :one => "one" }' 
   end 
   
   # argument :one was automagically passed from task :first. 
   task :second, :one do |t, args| 
       puts args.inspect # => '{ :one => "one" }' 
   end 
   
   $ rake first[one] 
   

2. 通過Rake::Task#invoke直接調用任務：

   # accepts arguments :one, :two and passes them to the :second task. 
   task :first, :one, :two do |t, args| 
       puts args.inspect # => '{ :one => "1", :two => "2" }' 
       task(:second).invoke(args[:one], args[:two]) 
   end 
   
   # accepts arguments :third, :fourth which got passed via #invoke. 
   # notice that arguments are passed by position rather than name. 
   task :second, :third, :fourth do |t, args| 
       puts args.inspect # => '{ :third => "1", :fourth => "2" }' 
   end 
   
   $ rake first[1, 2] 
   

3. 另一種解決方案是猴子補丁犁耙的主要應用對象Rake::Application
   並用它來存儲任意值：

   class Rake::Application 
       attr_accessor :my_data 
   end 
   
   task :first => :second do 
       puts Rake.application.my_data # => "second" 
   end 
   
   task :second => :third do 
       puts Rake.application.my_data # => "third" 
       Rake.application.my_data = "second" 
   end 
   
   task :third do 
       Rake.application.my_data = "third" 
   end 
   
   $ rake first 
   

Answer 2

設置屬性似乎是一個魅力的工作了。

只要確保將任務依賴關係設置爲設置所需屬性的任務即可。

# set the attribute I want to use in another task 
task :buy_puppy, [:name] do |_, args| 
    name = args[:name] || 'Rover' 
    @dog = Dog.new(name) 
end 

# task I actually want to run 
task :walk_dog => :buy_puppy do 
    @dog.walk 
end