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< ? php
/*
* Twitter Cards
*
* Hooks onto the Open Graph protocol and extends it by adding only the tags
* we need for twitter cards .
*
* @ see / wp - content / blog - plugins / open - graph . php
* @ see https :// dev . twitter . com / cards / overview
*/
class Jetpack_Twitter_Cards {
static function twitter_cards_tags ( $og_tags ) {
global $post ;
/**
* Maximum alt text length .
*
* @ see https :// developer . twitter . com / en / docs / tweets / optimize - with - cards / overview / summary - card - with - large - image . html
*/
$alt_length = 420 ;
if ( post_password_required () ) {
return $og_tags ;
}
/** This action is documented in class.jetpack.php */
if ( apply_filters ( 'jetpack_disable_twitter_cards' , false ) ) {
return $og_tags ;
}
/*
* These tags apply to any page ( home , archives , etc )
*/
// If we have information on the author/creator, then include that as well
if ( ! empty ( $post ) && ! empty ( $post -> post_author ) ) {
/** This action is documented in modules/sharedaddy/sharing-sources.php */
$handle = apply_filters ( 'jetpack_sharing_twitter_via' , '' , $post -> ID );
if ( ! empty ( $handle ) && ! self :: is_default_site_tag ( $handle ) ) {
$og_tags [ 'twitter:creator' ] = self :: sanitize_twitter_user ( $handle );
}
}
$site_tag = self :: site_tag ();
/** This action is documented in modules/sharedaddy/sharing-sources.php */
$site_tag = apply_filters ( 'jetpack_sharing_twitter_via' , $site_tag , ( is_singular () ? $post -> ID : null ) );
/** This action is documented in modules/sharedaddy/sharing-sources.php */
$site_tag = apply_filters ( 'jetpack_twitter_cards_site_tag' , $site_tag , $og_tags );
if ( ! empty ( $site_tag ) ) {
$og_tags [ 'twitter:site' ] = self :: sanitize_twitter_user ( $site_tag );
}
if ( ! is_singular () || ! empty ( $og_tags [ 'twitter:card' ] ) ) {
/**
* Filter the default Twitter card image , used when no image can be found in a post .
*
* @ module sharedaddy , publicize
*
* @ since 5.9 . 0
*
* @ param string $str Default image URL .
*/
$image = apply_filters ( 'jetpack_twitter_cards_image_default' , '' );
if ( ! empty ( $image ) ) {
$og_tags [ 'twitter:image' ] = $image ;
}
return $og_tags ;
}
$the_title = get_the_title ();
if ( ! $the_title ) {
$the_title = get_bloginfo ( 'name' );
}
$og_tags [ 'twitter:text:title' ] = $the_title ;
/*
* The following tags only apply to single pages .
*/
$card_type = 'summary' ;
// Try to give priority to featured images
if ( class_exists ( 'Jetpack_PostImages' ) ) {
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$post_image = Jetpack_PostImages :: get_image (
$post -> ID ,
array (
'width' => 144 ,
'height' => 144 ,
)
);
if ( ! empty ( $post_image ) && is_array ( $post_image ) ) {
// 4096 is the maximum size for an image per https://developer.twitter.com/en/docs/tweets/optimize-with-cards/overview/summary .
if (
isset ( $post_image [ 'src_width' ], $post_image [ 'src_height' ] )
&& ( int ) $post_image [ 'src_width' ] <= 4096
&& ( int ) $post_image [ 'src_height' ] <= 4096
) {
// 300x157 is the minimum size for a summary_large_image per https://developer.twitter.com/en/docs/tweets/optimize-with-cards/overview/summary-card-with-large-image .
if ( ( int ) $post_image [ 'src_width' ] >= 300 && ( int ) $post_image [ 'src_height' ] >= 157 ) {
$card_type = 'summary_large_image' ;
$og_tags [ 'twitter:image' ] = esc_url ( add_query_arg ( 'w' , 640 , $post_image [ 'src' ] ) );
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} else {
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$og_tags [ 'twitter:image' ] = esc_url ( add_query_arg ( 'w' , 144 , $post_image [ 'src' ] ) );
}
// Add the alt tag if we have one.
if ( ! empty ( $post_image [ 'alt_text' ] ) ) {
// Shorten it if it is too long.
if ( strlen ( $post_image [ 'alt_text' ] ) > $alt_length ) {
$og_tags [ 'twitter:image:alt' ] = esc_attr ( mb_substr ( $post_image [ 'alt_text' ], 0 , $alt_length ) . '…' );
} else {
$og_tags [ 'twitter:image:alt' ] = esc_attr ( $post_image [ 'alt_text' ] );
}
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}
}
}
}
// Only proceed with media analysis if a featured image has not superseded it already.
if ( empty ( $og_tags [ 'twitter:image' ] ) && empty ( $og_tags [ 'twitter:image:src' ] ) ) {
if ( ! class_exists ( 'Jetpack_Media_Summary' ) && defined ( 'IS_WPCOM' ) && IS_WPCOM ) {
include WP_CONTENT_DIR . '/lib/class.wpcom-media-summary.php' ;
}
if ( ! class_exists ( 'Jetpack_Media_Summary' ) ) {
jetpack_require_lib ( 'class.media-summary' );
}
// Test again, class should already be auto-loaded in Jetpack.
// If not, skip extra media analysis and stick with a summary card
if ( class_exists ( 'Jetpack_Media_Summary' ) ) {
$extract = Jetpack_Media_Summary :: get ( $post -> ID );
if ( 'gallery' == $extract [ 'type' ] ) {
list ( $og_tags , $card_type ) = self :: twitter_cards_define_type_based_on_image_count ( $og_tags , $extract );
} elseif ( 'video' == $extract [ 'type' ] ) {
// Leave as summary, but with large pict of poster frame (we know those comply to Twitter's size requirements)
$card_type = 'summary_large_image' ;
$og_tags [ 'twitter:image' ] = esc_url ( add_query_arg ( 'w' , 640 , $extract [ 'image' ] ) );
} else {
list ( $og_tags , $card_type ) = self :: twitter_cards_define_type_based_on_image_count ( $og_tags , $extract );
}
}
}
$og_tags [ 'twitter:card' ] = $card_type ;
// Make sure we have a description for Twitter, their validator isn't happy without some content (single space not valid).
if ( ! isset ( $og_tags [ 'og:description' ] ) || '' == trim ( $og_tags [ 'og:description' ] ) || __ ( 'Visit the post for more.' , 'jetpack' ) == $og_tags [ 'og:description' ] ) { // empty( trim( $og_tags['og:description'] ) ) isn't valid php
$has_creator = ( ! empty ( $og_tags [ 'twitter:creator' ] ) && '@wordpressdotcom' != $og_tags [ 'twitter:creator' ] ) ? true : false ;
if ( ! empty ( $extract ) && 'video' == $extract [ 'type' ] ) { // use $extract['type'] since $card_type is 'summary' for video posts
/* translators: %s is the post author */
$og_tags [ 'twitter:description' ] = ( $has_creator ) ? sprintf ( __ ( 'Video post by %s.' , 'jetpack' ), $og_tags [ 'twitter:creator' ] ) : __ ( 'Video post.' , 'jetpack' );
} else {
/* translators: %s is the post author */
$og_tags [ 'twitter:description' ] = ( $has_creator ) ? sprintf ( __ ( 'Post by %s.' , 'jetpack' ), $og_tags [ 'twitter:creator' ] ) : __ ( 'Visit the post for more.' , 'jetpack' );
}
}
if ( empty ( $og_tags [ 'twitter:image' ] ) && empty ( $og_tags [ 'twitter:image:src' ] ) ) {
/** This action is documented in class.jetpack-twitter-cards.php */
$image = apply_filters ( 'jetpack_twitter_cards_image_default' , '' );
if ( ! empty ( $image ) ) {
$og_tags [ 'twitter:image' ] = $image ;
}
}
return $og_tags ;
}
static function sanitize_twitter_user ( $str ) {
return '@' . preg_replace ( '/^@/' , '' , $str );
}
static function is_default_site_tag ( $site_tag ) {
return in_array ( $site_tag , array ( '@wordpressdotcom' , '@jetpack' , 'wordpressdotcom' , 'jetpack' ) );
}
static function prioritize_creator_over_default_site ( $site_tag , $og_tags = array () ) {
if ( ! empty ( $og_tags [ 'twitter:creator' ] ) && self :: is_default_site_tag ( $site_tag ) ) {
return $og_tags [ 'twitter:creator' ];
}
return $site_tag ;
}
static function twitter_cards_define_type_based_on_image_count ( $og_tags , $extract ) {
$card_type = 'summary' ;
$img_count = $extract [ 'count' ][ 'image' ];
if ( empty ( $img_count ) ) {
// No images, use Blavatar as a thumbnail for the summary type.
if ( function_exists ( 'blavatar_domain' ) ) {
$blavatar_domain = blavatar_domain ( site_url () );
if ( blavatar_exists ( $blavatar_domain ) ) {
$og_tags [ 'twitter:image' ] = blavatar_url ( $blavatar_domain , 'img' , 240 );
}
}
// Second fall back, Site Logo
if ( empty ( $og_tags [ 'twitter:image' ] ) && ( function_exists ( 'jetpack_has_site_logo' ) && jetpack_has_site_logo () ) ) {
$og_tags [ 'twitter:image' ] = jetpack_get_site_logo ( 'url' );
}
// Third fall back, Site Icon
if ( empty ( $og_tags [ 'twitter:image' ] ) && has_site_icon () ) {
$og_tags [ 'twitter:image' ] = get_site_icon_url ( '240' );
}
// Not falling back on Gravatar, because there's no way to know if we end up with an auto-generated one.
} elseif ( $img_count && ( 'image' == $extract [ 'type' ] || 'gallery' == $extract [ 'type' ] ) ) {
// Test for $extract['type'] to limit to image and gallery, so we don't send a potential fallback image like a Gravatar as a photo post.
$card_type = 'summary_large_image' ;
$og_tags [ 'twitter:image' ] = esc_url ( add_query_arg ( 'w' , 1400 , ( empty ( $extract [ 'images' ] ) ) ? $extract [ 'image' ] : $extract [ 'images' ][ 0 ][ 'url' ] ) );
}
return array ( $og_tags , $card_type );
}
static function twitter_cards_output ( $og_tag ) {
return ( false !== strpos ( $og_tag , 'twitter:' ) ) ? preg_replace ( '/property="([^"]+)"/' , 'name="\1"' , $og_tag ) : $og_tag ;
}
static function settings_init () {
add_settings_section ( 'jetpack-twitter-cards-settings' , 'Twitter Cards' , '__return_false' , 'sharing' );
add_settings_field (
'jetpack-twitter-cards-site-tag' ,
__ ( 'Twitter Site Tag' , 'jetpack' ),
array ( __CLASS__ , 'settings_field' ),
'sharing' ,
'jetpack-twitter-cards-settings' ,
array (
'label_for' => 'jetpack-twitter-cards-site-tag' ,
)
);
}
static function sharing_global_options () {
do_settings_fields ( 'sharing' , 'jetpack-twitter-cards-settings' );
}
static function site_tag () {
$site_tag = ( defined ( 'IS_WPCOM' ) && IS_WPCOM ) ?
trim ( get_option ( 'twitter_via' ) ) :
Jetpack_Options :: get_option_and_ensure_autoload ( 'jetpack-twitter-cards-site-tag' , '' );
if ( empty ( $site_tag ) ) {
/** This action is documented in modules/sharedaddy/sharing-sources.php */
return apply_filters ( 'jetpack_sharing_twitter_via' , '' , null );
}
return $site_tag ;
}
static function settings_field () {
wp_nonce_field ( 'jetpack-twitter-cards-settings' , 'jetpack_twitter_cards_nonce' , false );
?>
< input type = " text " id = " jetpack-twitter-cards-site-tag " class = " regular-text " name = " jetpack-twitter-cards-site-tag " value = " <?php echo esc_attr( get_option( 'jetpack-twitter-cards-site-tag' ) ); ?> " />
< p class = " description " style = " width: auto; " >< ? php esc_html_e ( 'The Twitter username of the owner of this site\'s domain.' , 'jetpack' ); ?> </p>
< ? php
}
static function settings_validate () {
if ( wp_verify_nonce ( $_POST [ 'jetpack_twitter_cards_nonce' ], 'jetpack-twitter-cards-settings' ) ) {
update_option ( 'jetpack-twitter-cards-site-tag' , trim ( ltrim ( strip_tags ( $_POST [ 'jetpack-twitter-cards-site-tag' ] ), '@' ) ) );
}
}
static function init () {
add_filter ( 'jetpack_open_graph_tags' , array ( __CLASS__ , 'twitter_cards_tags' ) );
add_filter ( 'jetpack_open_graph_output' , array ( __CLASS__ , 'twitter_cards_output' ) );
add_filter ( 'jetpack_twitter_cards_site_tag' , array ( __CLASS__ , 'site_tag' ), - 99 );
add_filter ( 'jetpack_twitter_cards_site_tag' , array ( __CLASS__ , 'prioritize_creator_over_default_site' ), 99 , 2 );
add_action ( 'admin_init' , array ( __CLASS__ , 'settings_init' ) );
add_action ( 'sharing_global_options' , array ( __CLASS__ , 'sharing_global_options' ) );
add_action ( 'sharing_admin_update' , array ( __CLASS__ , 'settings_validate' ) );
}
}
Jetpack_Twitter_Cards :: init ();