class Phlex::Context

def around_render
	return yield if !@fragments || @halt_signal
	catch do |signal|
		@halt_signal = signal
		yield
	end
end

def begin_target(id)
	@in_target_fragment = id
end

def capturing_into(new_buffer)
	original_buffer = @buffer
	original_capturing = @capturing
	original_fragments = @fragments
	begin
		@buffer = new_buffer
		@capturing = true
		@fragments = nil
		yield
	ensure
		@buffer = original_buffer
		@capturing = original_capturing
		@fragments = original_fragments
	end
	new_buffer
end

def end_target
	@fragments.delete(@in_target_fragment)
	@in_target_fragment = false
	throw @halt_signal if @fragments.length == 0
end

def initialize(user_context = {})
	@buffer = +""
	@capturing = false
	@user_context = user_context
	@fragments = nil
	@in_target_fragment = false
	@halt_signal = nil
end

def target
	@buffer
end

def target_fragments(fragments)
	@fragments = fragments.to_h { |it| [it, true] }
end