I am new to CI. I am using version 2. I noticed like other frameworks CI didn't have folders like assets and layout. Where do i place files like css and js and images. Also where is the layout folder.
You can place your assets directory wherever you desire, putting it under the root CodeIgniter directory is usually the norm.
CodeIgniter has no reason to include an assets directory as that's usually a front-end requirement, of which CI isn't made for (it's a back end MVC framework).
a simple answer is no. CI don't have that. You need to manually create.
And if you are coming from Yii, Ci doesn't implement that feature of Layout.
EDIT
by default, CI doesn't have. You can tweak it but easier implementation is
$this->load->view('header', $param1);
$this->load->view('content', $param2);
$this->load->view('footer', $param3);
where param1, param2, .... are variables you want to pass it to view.
CI will add the views in that order.
and remember, don't put .php while at the end of the filename in view().
Is the simple answer, you have to extend CIs functionality and use a library from a third party to provide these features for you. CI doesn't focus on the aesthetics of the "front-end". Its primary focus was "back-end".
look into Phil Sturgeons template library, and CI Sprinkles library first is for layout/theme/partials management, second is for asset management js/css minification and caching.
Phil's Template Library: http://philsturgeon.co.uk/demos/codeigniter-template/user_guide/
Sprinkles Library: https://github.com/edmundask/Sprinkle
This is a great intro video how to do such. I have used this in the past, before i got into using Sparks. http://www.youtube.com/watch?v=gvGymDhY49E
In 2.1 sparks aren't included however it is in the dev builds of CI so im sure at a later date it will be merged in with the base code. FOr now you can use this site to install Sparks to help you manage third party libraries.
You don't have to use a template library.
You don't have to programmatically serve the CSS and JS it can just be part of a view file.
But, you can if you want to! CI is incredibly flexible. We've written our own template library that works great for us (we'll release it soon, just checking that it works how we want it to...) but it might not suit the way you work.
Try using this PHP layout manager library, can be integrated with codeigniter easily:
https://github.com/mahadazad/php-layout-manager
its easy to setup and use.
look for assets helper to load css and js file anywhere..