What does = fl mean in a haml view

I've inherited an app that has this haml to pull in an index.html.haml file for the "home" 开发者_开发技巧controller.

= fl
- if logged_in?
  = render :partial => 'logged_in_home'
- else
  = render :partial => 'marketing_home'

The if statement is clear, but what is the = fl doing? I can't find that anywhere in haml documentation or by googling it.

= fl is not a built-in haml method. You could try to see if it defined in any of the following places:

• app/controllers/application_controller
• app/helpers/application_helper
• app/helpers/home_helper
• any other app/helpers/*_helper file
• library codes (lib/*)
• plugin / gem codes

My guess is that it's a local variable, especially if you are inside a partial. What happens when you run the page? What appears above the partials?

I have no idea what fl is in your application as it probably defined by your application or one of the plugins.

But I will tell you the magic trick to figure it out. Its actually very simple:

• Stick a debugger just before it ;)

Just do

= require 'ruby-debug';debugger;fl

And refresh your page. The server should stop at this line. Use s to step inside 'fl' function and you will find out exactly where is it in 99.99% of the cases (*)

• well, there might be cases when it will not help much, when for example a method is defined dynamically w/o properly setting source files and line.