Calling string in separate file in CodeIgniter - codeigniter

Question

I'm building a profanity/racial slur filter for my website. I have it working, but my preg_match string is quite long. I'm just wondering if there is some way to host this long string in a separate file in CodeIgniter and then call it when I need to in the preg_match.
I have googled this and I couldn't find anything, so I thought I would ask here.
What I'm doing now is hosting my string in the model and then calling this:
if(preg_match($filterRegex)){
databaseStuffHere();
}

Answer 1

Here are a few options. Depending on how and where you are using this string and function, one may be better than the others.
Config
You could store the value as a config, in application/config/config.php
$config['filter_regex'] = 'yourReallyLongString';
The primary config is auto-loaded by CodeIgniter, so you can use it like so:
$filterRegex = $this->config->item('filter_regex');
if(preg_match($filterRegex, $subject))
{
databaseStuffHere();
}
Constant
If you're using this long string in several places and it would be useful to have global access, you could define it as as constant in application/config/constants.php. It will also prevent you from accidentally redefining the value.
define('FILTER_REGEX', 'yourReallyLongString');
Then use it with your function like this:
$filterRegex = FILTER_REGEX;
if(preg_match($filterRegex, $subject))
{
databaseStuffHere();
}
Helper
Finally, you could use a helper. You can load the helper when required, or auto-load it. You can create your own helper in application/helpers/. It could look something like this:
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
if ( ! function_exists('filter_slurs'))
{
function filter_slurs($subject = '')
{
$filter_regex = 'yourReallyLongString';
if (preg_match($filter_regex, $subject))
{
return FALSE;
}
else
{
return TRUE;
}
}
}
Having a function to handle this may make your code easier to follow and more meaningful, for example, in your controller, you could use it like this:
$this->load->helper('slur_filter_helper'); //assumes the helper file is: slur_filter_helper.php
if(filter_slurs($subject))
{
//do something
}
else
{
//do something else
}

Answer 2

You can use it with config file (system/application/config/config.php) to set configuration related variables.
====================== DEFINE WHAT YOU WANT in config.php ===========================
$config['REQUIRED_SRTING'] = 'YOUR_REQUIRED_LONG_STRING_OR_WHAT_YOU_WANT_STORE';
But best place to set constant is
(system/application/config/constants.php) to store site preference constants.
===================DEFINE WHAT YOU WANT in constants.php=========================
define('CONSTANT_STRING','YOUR_REQUIRED_LONG_STRING_OR_WHAT_YOU_WANT_STORE');