Best way to include helper class in sub-controller : require_once or JLoader

Question

I have created a helper file test.php as following:

administrator/components/com_compname/helpers/test.php

class TestHelper{
   //class methods
}

In controllers/subcontrollername.php We can use either of them:

1) require_once(JPATH_COMPONENT.DIRECTORY_SEPARATOR.'helpers'.DIRECTORY_SEPARATOR.'test.php' );

2) JLoader::register('TestHelper','/path/to/test.php');

But I am wondering which of the two is appropriate and why or does this even matter or not. Can anyone please guide me on this.

Answer 1

Actually JLoader::register('TestHelper','/path/to/test.php'); dosen't load file, it just registers it to be able to autoload file if class is instantiated.

Do require it instantly, you want to use:

JLoader::import('TestHelper','/path/to/test.php');

Note: for this your file name should be TestHelper.php.

which will

1. include_once the file if it exists (with require_once you would get PHP error, if it dosen't exist. Now you would get pretty Joomla! error).

2. Will remember that this file is already loaded and wont include_once it again. This results in minor performance gain.

which won't

1. JLoader::register() your class, so you can't use JLoader::load() later.

All in all:

1. Minor performance gain.
2. It's good practice to follow coding style of framework (though Joomla! dosen't do it everywhere itself).
3. You can use dot notation for class name (not applicable for *Helper classes.).

Dot notation example

jimport('sub.path.classname','/path/to/')

would include_once file in /path/to/sub/path/classname.php

NOTE

JLoader::import('TestHelper','/path/to/test.php')

has shorthand

jimport('TestHelper','/path/to/test.php')