inc/library/amp/class-amp.php
<?php
/**
* Super_Awesome_Theme_AMP class
*
* @package Super_Awesome_Theme
* @license GPL-2.0-or-later
* @link https://super-awesome-author.org/themes/super-awesome-theme/
*/
/**
* Class responsible for handling AMP support.
*
* @since 1.0.0
*/
final class Super_Awesome_Theme_AMP extends Super_Awesome_Theme_Theme_Component_Base {
/**
* Internal storage for whether the current context is an AMP endpoint.
*
* @since 1.0.0
* @var bool|null
*/
protected $is_amp_endpoint = null;
/**
* Default key => value pairs to use for AMP state.
*
* @since 1.0.0
* @var array
*/
private $state = array();
/**
* Constructor.
*
* Sets the required dependencies.
*
* @since 1.0.0
*/
public function __construct() {
$this->require_dependency_class( 'Super_Awesome_Theme_Theme_Support' );
$this->require_dependency_class( 'Super_Awesome_Theme_Assets' );
$this->require_dependency_class( 'Super_Awesome_Theme_Comments' );
$this->require_dependency_class( 'Super_Awesome_Theme_Navbar' );
$this->require_dependency_class( 'Super_Awesome_Theme_Sticky_Elements' );
}
/**
* Checks whether the current context is an AMP endpoint.
*
* @since 1.0.0
*
* @return bool True if an AMP endpoint, false otherwise.
*/
public function is_amp() {
if ( ! did_action( 'parse_query' ) ) {
return false;
}
if ( null === $this->is_amp_endpoint ) {
$this->is_amp_endpoint = function_exists( 'is_amp_endpoint' ) && is_amp_endpoint();
}
return $this->is_amp_endpoint;
}
/**
* Gets the identifier for managing state in AMP.
*
* @since 1.0.0
*
* @return string Identifier of the amp-state tag.
*/
public function get_state_id() {
return 'superAwesomeTheme';
}
/**
* Magic call method.
*
* @since 1.0.0
*
* @param string $method Method name.
* @param array $args Method arguments.
*
* @throws BadMethodCallException Thrown when method name is invalid.
*/
public function __call( $method, $args ) {
switch ( $method ) {
case 'register_support':
case 'register_sanitizer':
case 'maybe_prevent_scripts':
case 'fix_header_video_body_class':
case 'handle_sticky_elements':
case 'print_state':
return call_user_func_array( array( $this, $method ), $args );
default:
/* translators: %s: method name */
throw new BadMethodCallException( sprintf( __( 'Call to undefined method %s', 'super-awesome-theme' ), __CLASS__ . '::' . $method . '()' ) );
}
}
/**
* Registers theme support for 'amp'.
*
* @since 1.0.0
*/
protected function register_support() {
$this->get_dependency( 'theme_support' )->add_feature( new Super_Awesome_Theme_Args_Theme_Feature(
'amp',
array(
'comments_live_list' => true,
)
) );
}
/**
* Registers the theme-specific AMP sanitizer by filtering the available AMP sanitizers.
*
* @since 1.0.0
*
* @param array $sanitizers AMP content sanitizers.
* @return array Filtered sanitizers.
*/
protected function register_sanitizer( array $sanitizers ) {
if ( ! class_exists( 'Super_Awesome_Theme_AMP_Sanitizer' ) ) {
require_once dirname( __FILE__ ) . '/class-amp-sanitizer.php';
}
$sanitizers['Super_Awesome_Theme_AMP_Sanitizer'] = array(
'state_id' => $this->get_state_id(),
);
return $sanitizers;
}
/**
* Prevents scripts from being enqueued if in AMP context.
*
* @since 1.0.0
*/
protected function maybe_prevent_scripts() {
if ( ! $this->is_amp() ) {
return;
}
// Prevent the JS support detection script.
remove_action( 'wp_head', array( $this->get_dependency( 'assets' ), 'print_detect_js_svg_support_script' ), 0 );
// Prevent comment reply script from being enqueued.
remove_action( 'wp_enqueue_scripts', array( $this->get_dependency( 'comments' ), 'maybe_enqueue_comment_reply_script' ), 20 );
// Prevent any script from being enqueued.
add_filter( 'super_awesome_theme_enqueue_script', '__return_false' );
}
/**
* Replaces the 'has-header-video-loading' class with the 'has-header-video' class immediately.
*
* @since 1.0.0
*
* @param array $classes List of CSS classes to add to the body element.
* @return array Filtered CSS classes.
*/
protected function fix_header_video_body_class( $classes ) {
$key = array_search( 'has-header-video-loading', $classes, true );
if ( false !== $key ) {
$classes[ $key ] = 'has-header-video';
}
return $classes;
}
/**
* Handles dynamic sticky content if in AMP context.
*
* The amp-position-observer tag is used to detect whether content should become sticky or not.
*
* @since 1.0.0
*/
protected function handle_sticky_elements() {
// Skip for now since it is neither possible to set state nor animate position style based on position observer.
if ( ! $this->is_amp() || true ) {
return;
}
$sticky_elements = $this->get_dependency( 'sticky_elements' )->get_registered_sticky_elements();
$state_id = $this->get_state_id();
foreach ( $sticky_elements as $id => $sticky ) {
if ( ! $sticky->get_setting()->get_value() ) {
continue;
}
$selector = $sticky->get_prop( Super_Awesome_Theme_Sticky_Element::PROP_SELECTOR );
$location = $sticky->get_prop( Super_Awesome_Theme_Sticky_Element::PROP_LOCATION );
// The amp-position-observer can only deal with IDs.
if ( '#' !== substr( $selector, 0, 1 ) ) {
continue;
}
$state_property = implode( '', array_map( 'ucfirst', explode( '_', $id ) ) );
$state_property = strtolower( substr( $state_property, 0, 1 ) ) . substr( $state_property, 1 ) . 'Sticky';
$animation_id = 'make' . ucfirst( $state_property );
$animation_data = array(
'duration' => '0.25s',
'animations' => array(
'selector' => $selector,
'fill' => 'both',
'keyframes' => array(
array(
'position' => 'fixed',
'right' => 0,
'left' => 0,
$location => 0,
),
),
),
);
?>
<amp-animation id="<?php echo esc_attr( $animation_id ); ?>" layout="nodisplay">
<script type="application/json">
<?php echo wp_json_encode( $animation_data ); ?>
</script>
</amp-animation>
<amp-position-observer target-id="<?php echo esc_attr( substr( $selector, 1 ) ); ?>"
on="<?php echo esc_attr( "enter:{$animation_id}.start" ); ?>"
layout="nodisplay"
>
</amp-position-observer>
<?php
}
}
/**
* Prints the amp-state tag containing the default state if in AMP context.
*
* @since 1.0.0
*/
protected function print_state() {
if ( ! $this->is_amp() ) {
return;
}
$this->state = array(
'mobileMenuExpanded' => $this->get_dependency( 'navbar' )->is_side(),
'sideNavbarExpanded' => ! $this->get_dependency( 'navbar' )->is_side(),
);
?>
<amp-state id="<?php echo esc_attr( $this->get_state_id() ); ?>">
<script type="application/json">
<?php echo wp_json_encode( $this->state ); ?>
</script>
</amp-state>
<?php
}
/**
* Adds hooks and runs other processes required to initialize the component.
*
* @since 1.0.0
*/
protected function run_initialization() {
add_action( 'after_setup_theme', array( $this, 'register_support' ), 10, 0 );
add_filter( 'amp_content_sanitizers', array( $this, 'register_sanitizer' ), 10, 1 );
add_action( 'wp', array( $this, 'maybe_prevent_scripts' ), 10, 0 );
add_filter( 'body_class', array( $this, 'fix_header_video_body_class' ), 11, 1 );
add_action( 'wp_footer', array( $this, 'handle_sticky_elements' ), 0, 0 );
add_action( 'wp_footer', array( $this, 'print_state' ), 10, 0 );
}
}