<?php
/**
* Quiz shortcode.
*
* Usage:
*
* [quiz]
* [question]What's the right answer?[/question]
* [wrong]This one?[explanation]Nope[/explanation][/wrong]
* [answer]Yes, this is the one![explanation]Yay![/explanation][/answer]
* [wrong]Maybe this one[explanation]Keep trying[/explanation][/wrong]
* [wrong]How about this one?[explanation]Try again[/explanation][/wrong]
* [/quiz]
*/
class Quiz_Shortcode {
/**
* Parameters admitted by [quiz] shortcode.
*
* @since 4.5.0
*
* @var array
*/
private static $quiz_params = array();
/**
* Whether the scripts were enqueued.
*
* @since 4.5.0
*
* @var bool
*/
private static $scripts_enqueued = false;
/**
* In a8c training, store user currently logged in.
*
* @since 4.5.0
*
* @var null
*/
private static $username = null;
/**
* Whether the noscript tag was already printed.
*
* @since 4.5.0
*
* @var bool
*/
private static $noscript_info_printed = false;
/**
* Whether JavaScript is available.
*
* @since 4.5.0
*
* @var null
*/
private static $javascript_unavailable = null;
/**
* Register all shortcodes.
*
* @since 4.5.0
*/
public static function init() {
add_shortcode( 'quiz', array( __CLASS__, 'shortcode' ) );
add_shortcode( 'question', array( __CLASS__, 'question_shortcode' ) );
add_shortcode( 'answer', array( __CLASS__, 'answer_shortcode' ) );
add_shortcode( 'wrong', array( __CLASS__, 'wrong_shortcode' ) );
add_shortcode( 'explanation', array( __CLASS__, 'explanation_shortcode' ) );
}
/**
* Enqueue assets needed by the quiz,
*
* @since 4.5.0
*/
private static function enqueue_scripts() {
wp_enqueue_style( 'quiz', plugins_url( 'css/quiz.css', __FILE__ ) );
wp_enqueue_script( 'quiz', plugins_url( 'js/quiz.js', __FILE__ ), array( 'jquery' ), null, true );
}
/**
* Check if this is a feed and thus JS is unavailable.
*
* @since 4.5.0
*
* @return bool|null
*/
private static function is_javascript_unavailable() {
if ( ! is_null( self::$javascript_unavailable ) ) {
return self::$javascript_unavailable;
}
if ( is_feed() ) {
return self::$javascript_unavailable = true;
}
return self::$javascript_unavailable = false;
}
/**
* Display message when JS is not available.
*
* @since 4.5.0
*
* @return string
*/
private static function noscript_info() {
if ( self::$noscript_info_printed ) {
return '';
}
self::$noscript_info_printed = true;
return '<noscript><div><i>' . esc_html__( 'Please view this post in your web browser to complete the quiz.', 'jetpack' ) . '</i></div></noscript>';
}
/**
* Check if we're in WordPress.com.
*
* @since 4.5.0
*
* @return bool
*/
public static function is_wpcom() {
return defined( 'IS_WPCOM' ) && IS_WPCOM;
}
/**
* Parse shortcode arguments and render its output.
*
* @since 4.5.0
*
* @param array $atts Shortcode parameters.
* @param string $content Content enclosed by shortcode tags.
*
* @return string
*/
public static function shortcode( $atts, $content = null ) {
// There's nothing to do if there's nothing enclosed.
if ( null == $content ) {
return '';
}
$id = '';
if ( self::is_javascript_unavailable() ) {
// in an e-mail print the question and the info sentence once per question, too
self::$noscript_info_printed = false;
} else {
if ( ! self::$scripts_enqueued ) {
// lazy enqueue cannot use the wp_enqueue_scripts action anymore
self::enqueue_scripts();
self::$scripts_enqueued = true;
}
$default_atts = self::is_wpcom()
? array(
'trackid' => '',
'a8ctraining' => '',
)
: array(
'trackid' => '',
);
self::$quiz_params = shortcode_atts( $default_atts, $atts );
if ( ! empty( self::$quiz_params[ 'trackid' ] ) ) {
$id .= ' data-trackid="' . esc_attr( self::$quiz_params[ 'trackid' ] ) . '"';
}
if ( self::is_wpcom() && ! empty( self::$quiz_params[ 'a8ctraining' ] ) ) {
if ( is_null( self::$username ) ) {
self::$username = wp_get_current_user()->user_login;
}
$id .= ' data-a8ctraining="'. esc_attr( self::$quiz_params[ 'a8ctraining' ] ) . '" data-username="' . esc_attr( self::$username ) . '"';
}
}
$quiz = self::do_shortcode( $content );
return '<div class="jetpack-quiz quiz"' . $id . '>' . $quiz . '</div>';
}
/**
* Strip line breaks, restrict allowed HTML to a few whitelisted tags and execute nested shortcodes.
*
* @since 4.5.0
*
* @param string $content
*
* @return mixed|string
*/
private static function do_shortcode( $content ) {
// strip autoinserted line breaks
$content = preg_replace( '#(<(?:br /|/?p)>\n?)*(\[/?[a-z]+\])(<(?:br /|/?p)>\n?)*#', '$2', $content );
// Add internal parameter so it's only rendered when it has it
$content = preg_replace( '/\[(question|answer|wrong|explanation)\]/i', '[$1 quiz_item="true"]', $content );
$content = do_shortcode( $content );
$content = wp_kses( $content, array(
'tt' => array(),
'pre' => array(),
'strong' => array(),
'i' => array(),
'br' => array(),
'img' => array( 'src' => true),
'div' => array( 'class' => true, 'data-correct' => 1, 'data-track-id' => 1, 'data-a8ctraining' => 1, 'data-username' => 1 ),
) );
return $content;
}
/**
* Render question.
*
* @since 4.5.0
*
* @param array $atts
* @param null $content
*
* @return string
*/
public static function question_shortcode( $atts, $content = null ) {
return isset( $atts['quiz_item'] )
? '<div class="jetpack-quiz-question question">' . self::do_shortcode( $content ) . '</div>'
: '';
}
/**
* Render correct answer.
*
* @since 4.5.0
*
* @param array $atts
* @param null $content
*
* @return string
*/
public static function answer_shortcode( $atts, $content = null ) {
if ( self::is_javascript_unavailable() ) {
return self::noscript_info();
}
return isset( $atts['quiz_item'] )
? '<div class="jetpack-quiz-answer answer" data-correct="1">' . self::do_shortcode( $content ) . '</div>'
: '';
}
/**
* Render wrong response.
*
* @since 4.5.0
*
* @param array $atts
* @param null $content
*
* @return string
*/
public static function wrong_shortcode( $atts, $content = null ) {
if ( self::is_javascript_unavailable() ) {
return self::noscript_info();
}
return isset( $atts['quiz_item'] )
? '<div class="jetpack-quiz-answer answer">' . self::do_shortcode( $content ) . '</div>'
: '';
}
/**
* Render explanation for wrong or right answer.
*
* @since 4.5.0
*
* @param array $atts
* @param null $content
*
* @return string
*/
public static function explanation_shortcode( $atts, $content = null ) {
if ( self::is_javascript_unavailable() ) {
return self::noscript_info();
}
return isset( $atts['quiz_item'] )
? '<div class="jetpack-quiz-explanation explanation">' . self::do_shortcode( $content ) . '</div>'
: '';
}
}
Quiz_Shortcode::init();