Question

I am new to codeigniter. I want to use file-based caching.I don’t know if I understood correctly.
1. Declare the following in the parent controller —$this->load->driver('cache');
2. $this->cache->file->save('foo', 'bar', 10); is used to save the file but i don’t know what are the parameters of this function and how to implement all these so that caching can be done.
Please help

Answer 1

http://codeigniter.com/user_guide/libraries/caching.html#example_usage
The manual has it – but it’s a bit hidden in the example:

if ( ! $foo = $this->cache->get('foo'))
{
     echo 'Saving to the cache!<br />';
     $foo = 'foobarbaz!';

     // Save into the cache for 5 minutes
     $this->cache->save('foo', $foo, 300);
}

‘foo’ -> the name for the variable you’re about to cache
$foo -> the variable to cache. It can be anything
300 -> time in seconds (60*5) – set to 0 for no expiry

So IF $foo is empty the cache file is recreated, else you can use $foo to load data.

Further notes:
http://codeigniter.com/user_guide/general/caching.html

A more flexible alternative could be this sparks library:
http://getsparks.org/packages/cache/show
I use it and it fits my needs for file-based caching very well.