Question

This is my code:

def block
  puts "from block"
  yield
end

block do
  puts "from command line"
  block do

  end
end

Here is the output:

from block
from command line
from block

I wonder how the second block could detect that its inside another block (of the same method).

So that the output will be this instead:

from block 1
from command line
from block 2

Is this possible? Because I want the nested block to be aware of this and run some additional code.

Thanks!

Answer 1

You could keep track of the block level with an instance variable, increment it whenever you enter a block, and decrement it whenever you leave a block:

def block
  @block_level ||= 0
  @block_level += 1

  puts "from block #@block_level"

  yield

  @block_level -= 1
end