Add custom post endpoints and misc. functionality

post-endpoints.php

<?php

/**
 * Handly place to define our endpoints all in one spot
 * @return array  Array of our endpoints
 */
function prefix_custom_endpoints() {
	return array(
		'portfolio',
		'testimonials',
		'alerts',
		'issues',
		'reports',
		'media',
	);
}

/**
 * Add the rewrite endpoints
 */
function prefix_add_endpoints() {
	foreach ( prefix_custom_endpoints() as $endpoint ) {
		add_rewrite_endpoint( $endpoint, EP_PERMALINK );
	}
}
add_action( 'init', 'prefix_add_endpoints' );

/**
 * Filter the request to make sure our empty
 * query vars are actually defined
 *
 * @param  array $q Query params
 * @return array    Modified query params
 */
function prefix_request_filter( $q ) {
	foreach ( prefix_custom_endpoints() as $key ) {
		$q[ $key ] = isset( $q[ $key ] );
	}

	return $q;
}
add_filter( 'request', 'prefix_request_filter' );

/**
 * Add a body class for each endpoint
 *
 * @param  array  $classes Array of body classes
 * @return array           Modified array of body classes
 */
function prefix_add_endpoint_body_class( $classes ) {

	// If endpoint, add class
	if ( $endpoint = prefix_active_endpoint() ) {
		$classes[] = 'endpoint-' . $endpoint;
	}

	return $classes;
}
add_filter( 'body_class', 'prefix_add_endpoint_body_class' );

/**
 * Easily check what endpoint you are on
 *
 * @param  string      $endpoint (optional) An endpoint to check if you are on a specific endpoint
 * @return bool|string           If checking a specific endpoint, return will be bool, otherwise will return the name
 */
function prefix_active_endpoint( $endpoint = null ) {
	$post_types_with_endpoint = array( 'page' );
	// If we are not on an endpoint post_type, bail
	if ( ! in_array( get_post_type(), $post_types_with_endpoint ) ) {
		return false;
	}

	// Check if a $endpoint was passed
	if ( ! is_null( $endpoint ) ) {
		// $endpoint will either be true if we are on the $endpoint, or false if we are not or it does not exist
		return get_query_var( $endpoint );
	} else {

		foreach ( prefix_custom_endpoints() as $endpoint ) {
			if ( get_query_var( $endpoint ) ) {
				return $endpoint;
			}
		}
	}

	// If nothing was true, we must be false
	return false;
}