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，因此不能单独调用它们？

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。

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]

通过Rake::Task#invoke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]

另一个解决方案是修补Rake的主应用程序对象Rake::Application 并用它来存储任意值：

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

Answer 2

设置属性似乎也像魅力一样。

确保将任务依赖项设置为设置所需属性的任务。

# 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

如何将参数从父任务传递到Rake中的子任务？

2 个答案: