codeigniter category -> subcategory -> subsubcategory system - codeigniter

Question

ok, so i'm very new to codeigniter and from what i have learned by now i can't figure out how can i create a dynamic category -> subcategory -> subsubcategory system. Can you give me some guidelines please...some references, anything to guide me on what should i learn to accomplish that? thanks
i should get my URL like this www.site.com/category/subcategory/subsubcategory/etc... , you know what i mean.

Answer 1

I have done this for the page manager in PyroCMS but it is no easy task.
Each page has its own slug and parent_id, then to read the correct page it loops through each of the page slugs and joins the child. It knows how many children there are so if there are 5 children it selects the 5th self-joined table.
Here is an example of the code:
public function get_by_path($segments = array())
{
// If the URI has been passed as a string, explode to create an array of segments
if(is_string($segments))
{
$segments = explode('/', $segments);
}
// Work out how many segments there are
$total_segments = count($segments);
// Which is the target alias (the final page in the tree)
$target_alias = 'p'.$total_segments;
// Start Query, Select (*) from Target Alias, from Pages
$this->db->select($target_alias.'.*');
$this->db->from('pages p1');
// Loop thorugh each Slug
$level = 1;
foreach( $segments as $segment )
{
// Current is the current page, child is the next page to join on.
$current_alias = 'p'.$level;
$child_alias = 'p'.($level - 1);
// We dont want to join the first page again
if($level != 1)
{
$this->db->join('pages '.$current_alias, $current_alias.'.parent_id = '.$child_alias.'.id');
}
// Add slug to where clause to keep us on the right tree
$this->db->where($current_alias . '.slug', $segment);
// Increment
++$level;
}
// Can only be one result
$this->db->limit(1);
return $this->db->get()->row();
}
It's a bit nuts but it works perfectly. This can be really slow so PyroCMS also maintains a look-up table which has id and the page URI to match quickly.
You can see the whole model here:
http://github.com/philsturgeon/pyrocms/blob/master/application/modules/core/pages/models/pages_m.php

Answer 2

you could:
create controller category, reroute some URIs to it and use it's internal logic to parse it's arguments to pick whatever article client requested:
About URLs:
http://codeigniter.com/user_guide/general/urls.html
About URI routing:
http://codeigniter.com/user_guide/general/routing.html

Answer 3

I agree with Phil's idea and I was also envisioning that you can create a separate module (if you use modular extensions for example) to handle the categories in a generic way. Then you can reuse that module in any other projects. Basically the new module may be able to handle categories and sub-categories (the hierarchy).