I have a basic question to beautiful working code I've found (paulund) for making a Custom Control by extending the 'WP_Customize_Control' Class. I am new to PHP, Programming and especially to OOP. So I wonder especially, what the first "condition" do, while the rest seems comprehensibly to me. I have a understanding problem with:
if ( ! class_exists( 'WP_Customize_Control' ) ) return NULL;
Read the php manual for "class_exists" and I read in a german blog, that the code above ensures, that we have no conflicts with other Plugins... .
I this is the idea of it, how does it work? Shouldn't the Class exist by Wordpress Core anyway? Sorry for my English. Many thanks in advance.