Blocks again...can you explain what is happening to my block?

[Bumppoman]

Phlex 1.2.1:

class Foo < Phlex::HTML
  def template(&)
    instance_eval(&)
  end

  def test_method
    text "Hello!"
  end
end

class Bar
  def template
    Foo.new do
      test_method
    end
  end
end

Expected result: "Hello"
Actual result: "no method error test_method..."

Why is the block being evaluated in the context of Bar rather than the context of Foo?

If I use the internal method to take my block back, everything works as expected:

class Foo < Phlex::HTML
  def template
    instance_eval(&@_content_block)
  end

  def test_method
    text "Hello!"
  end
end

class Bar
  def template
    Foo.new do
      test_method
    end
  end
end

Expected result: "Hello"
Actual result: "Hello"

Any recommendations here? Thanks!

[joeldrapper]

This is probably because Phlex wraps the block when calling template so you can yield it with the benefits of yield_content. (yield_content will treat the return value as text if it doesn’t do anything to the buffer while being yielded. It's how h1 { "Hello" } works.)

Bar should be updated to call test_method on the yielded object, which is the view unless you explicitly yielded something else. I would pick it up as |f| and call f.test_method.

class Bar < Phlex::HTML
  def template
    render Foo.new do |f|
      f.test_method
    end
  end
end

Foo can just yield the block and it will automatically yield(self) within a yield_content.

class Foo < Phlex::HTML
  def template
    yield
  end

  def test_method
    text "Hello!"
  end
end

Alternatively, Foo could pass the block to a tag which will yield it.

def template(&)
  div(&)
end