rails around_action 如何与 return 语句一起工作

Question

I am new to the ruby and RoR world and I have recently learned about blocks. I have read that return inside block actually returns from the top most function that called it

for example

def test 
    value = yield
    puts value

end

# prints "return inside block"
test do
      "return inside block"
end

# prints nothing
test do
      return "return inside block"
end

so if this is how blocks and "return" works in ruby, how come around_action don't behave the same?

for example

class TestController < ApplicationController
    around_action :aroundy
    def test
        render json: {amit:"hello"} 
        puts "hello"
        return
    end
    
    # prints after even though the action "test" calls return
    def aroundy
        puts "before"
        yield  
        puts "after"
    end
end

How is it possible that the code continues to run after the yield if I called return inside the action?

Answer 1

There's a big difference between these two situations: your action test is a method, not a block. This alone is enough to throw out all expectations that return should behave the same way as it does in blocks.

In addition, the way it's called is not as simple as in your first snippet. Here 's how around_action is implemented in rails, for example:

define_method "#{callback}_action" do |*names, &blk|
  _insert_callbacks(names, blk) do |name, options|
    set_callback(:process_action, callback, name, options)
  end
end