如何将参数从父任务传递到Rake中的子任务？

Question

我正在编写一个Rake脚本,其中包含带参数的任务.我想出了如何传递参数以及如何使任务依赖于其他任务.

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

• 我可以将参数从父任务传递给子任务吗？
• 有没有办法让子任务变为私有,所以不能独立调用它们？

Answer 1

我实际上可以想到在Rake任务之间传递参数的三种方法.

1. 使用Rake对参数的内置支持:

   # 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. 通过Rake::Task#invoke以下方式直接调用任务:

   # 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. 另一个解决方案是使用Rake的主应用程序对象Rake :: Application
   并使用它来存储任意值:

   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