Constantin Bosneaga has a recent post to his site that the CodeIgniter users out there could find helpful. It's an example of using the Layout pattern in a CI app to make a more flexible layout thanks to a library (source included in the post).
CodeIgniter is great framework by its simplicity. But when I moved from CakePHP, I really missed layout pattern. CodeIgniter documentations offers this way to include non-changing site header and footer. For sure it isn't flexible and does not show page structure in a clear way. For many years I use layout pattern. Layout describes whole page as a template with blocks for header, menu, content, etc.
He uses this library to handle the data for your layout, including the header items (like CSS, Javascript) and the definition of a global template. It also allows you to do template inheritance, making it simpler to reuse partial templates ("blocks").