Codeigniter: How can I check if a library method exists without loading the library?

I want to separate certain functions from controller methods into libraries to make them modular. Based on the URI I'm trying to route to a library method if it exists. But I'd have to load the library to check for the method with the php method_exists function. The only other way I've found to check for it is to put all the library methods in a config array and check for the method name there. Such as:

<?php
/**
 * Application_config.php
 */

$config['extensions'] = array(
 'News' => array(
  'library' => 'articles_library',
  'methods' => array(
   'articles',
   'article',
   'edit_article',
   'add_article',
   'delete_article'
  )
 )
);

and

<?php
/**
 * admin_controller.php
 *
 * all admin routes go to index
 */
class C3_base_controller extends Controller {
 public function ind开发者_开发问答ex() {
  $lib_chk = 0;
  $ext = $this->config->item('extensions');
  foreach($ext as $item) {
   foreach ($item['methods'] as $meth) {
    if ($this->uri->segment(2) == $meth) {
     $lib = $item['library'];
     echo $this->$lib->$meth();
     $lib_chk = 1;
    }
   }
  }
  if ($lib_chk == 0) {
   // rest of controller...
  }
 }
}

Is there a better way to check for the existence of a library method in each library without loading the libraries? Having to duplicate every method in the application config is just asking for it.

You can use

method_exists

For example, if you are checking for the database object if it's exists

if(method_exists($this->CI->db, 'set')){
// code ...
}

Are you pursuing modularity for reusable code or are you creating an application that has features that may or may not be present...as in plugins?

It's hard for me to imagine your base application having hard-coaded url's that lead to a library that may not exist. Can you test for the library rather than the method? That may be simpler to check a directory and load file names into an array, then see if the library required by a url or uri is in that array.

But if you need to stick to your array of existing method names, could you just regex for the method names by that occur after "function (space)" and followed by parenthesis?