Create multiple WordPress roles and limited capabilities for Schools

Personally I have set up many school websites and out of the box WordPress has a pretty sophisticated user roles and capabilities authoring engine. This can pretty much apply to any multiple user website but by just considering schools we can break it down in to user chunks.

So, schools have; Students, Staff, Teachers, Deputy Heads and probably a Head who will have more capabilities than others. Using the following code in your functions.php file you can firstly add multiple generic roles then at a later stage give them more capabilities like so:

// add multiple roles with basic capabilities for later use
function add_multiple_roles() {
	$roles = array('head' => 'Head','dep_head' => 'Deputy Head','teacher' => 'Teacher','staff' => 'Staff','student'=>'Student');

	$capabilities = array(
	    'read' => true,  // true allows this capability
	);

	foreach ($roles as $k => $v) {
		add_role( $k, __( $v ),  $capabilities );
	}
}
add_action( 'admin_init', 'add_multiple_roles');

function add_staff_caps() {
    // only relates to staff
    $role = get_role( 'staff' );
	// edit their own posts
    $role->add_cap( 'edit_posts' );
}
add_action( 'admin_init', 'add_staff_caps');

function add_teacher_caps() {
    // only relates to teacher
    $role = get_role( 'teacher' );
	// delete their own posts
    $role->add_cap( 'delete_posts' );
	// edit their own posts
    $role->add_cap( 'edit_posts' );
}
add_action( 'admin_init', 'add_teacher_caps');

function add_dep_head_caps() {
    // only relates to dep_head
    $role = get_role( 'dep_head' );
 	// publish their own posts
    $role->add_cap( 'publish_posts' );
 	// delete their own posts
    $role->add_cap( 'delete_published_posts' );
 	// edit their own published posts
    $role->add_cap( 'edit_published_posts' );
	// edit their own posts
    $role->add_cap( 'edit_posts' );
}
add_action( 'admin_init', 'add_dep_head_caps');

function add_head_caps() {
   $role = get_role( 'head' );
   // do whatever you see fit for the Head to do.....
}
add_action( 'admin_init', 'add_head_caps');

At some point you’ll probably want to change these capabilities but without getting yourself lost down a rabbit hole it’s probably worth mentioning that these capabilities are added to the database and if you think by removing them from your functions.php it is going to work as you would expect – think again!

This is not the case so, to chop and change between capabilities and user roles you’ll have to unregister them or remove them per role it they have been added previously. To show this as an example I’ve commented out the line that previously switch the capability on, if it wasn’t removed from the role it would still retain the capability eg:

function add_head_caps() {
   $role = get_role( 'head' );
   // do whatever you see fit for the Head to do...
   // it was switched on previously and commenting it out will not switch it off...
   // $role->add_cap( 'publish_posts' );
   // if it was previously added then you need to remove it....
   $role->remove_cap( 'publish_posts' );
}
add_action( 'admin_init', 'add_head_caps');

if you get in to a quagmire of not knowing where you are with capabilities you can always debug with the following to see what is going on:

print_r($role = get_role( 'head' ));