<?php // phpcs:ignore WordPress.Files.FileName.InvalidClassFileName
/**
* Class with methods to extract metadata from a post/page about videos, images, links, mentions embedded
* in or attached to the post/page.
*
* @package automattic/jetpack
*/
/**
* Class with methods to extract metadata from a post/page about videos, images, links, mentions embedded
* in or attached to the post/page.
*
* @todo Additionally, have some filters on number of items in each field
*/
class Jetpack_Media_Meta_Extractor {
// Some consts for what to extract.
const ALL = 255;
const LINKS = 1;
const MENTIONS = 2;
const IMAGES = 4;
const SHORTCODES = 8; // Only the keeper shortcodes below.
const EMBEDS = 16;
const HASHTAGS = 32;
/**
* Shortcodes to keep.
*
* For these, we try to extract some data from the shortcode, rather than just recording its presence (which we do for all)
* There should be a function get_{shortcode}_id( $atts ) or static method SomethingShortcode::get_{shortcode}_id( $atts ) for these.
*
* @var string[]
*/
private static $keeper_shortcodes = array(
'youtube',
'vimeo',
'hulu',
'ted',
'wpvideo',
'videopress',
);
/**
* Gets the specified media and meta info from the given post.
* NOTE: If you have the post's HTML content already and don't need image data, use extract_from_content() instead.
*
* @param int $blog_id The ID of the blog.
* @param int $post_id The ID of the post.
* @param int $what_to_extract A mask of things to extract, e.g. Jetpack_Media_Meta_Extractor::IMAGES | Jetpack_Media_Meta_Extractor::MENTIONS.
* @param boolean $extract_alt_text Should alt_text be extracted, defaults to false.
*
* @return array|WP_Error a structure containing metadata about the embedded things, or empty array if nothing found, or WP_Error on error.
*/
public static function extract( $blog_id, $post_id, $what_to_extract = self::ALL, $extract_alt_text = false ) {
// multisite?
if ( function_exists( 'switch_to_blog' ) ) {
switch_to_blog( $blog_id );
}
$post = get_post( $post_id );
if ( ! $post instanceof WP_Post ) {
if ( function_exists( 'restore_current_blog' ) ) {
restore_current_blog();
}
return array();
}
$content = $post->post_title . "\n\n" . $post->post_content;
$char_cnt = strlen( $content );
// prevent running extraction on really huge amounts of content.
if ( $char_cnt > 100000 ) { // about 20k English words.
$content = substr( $content, 0, 100000 );
}
$extracted = array();
// Get images first, we need the full post for that.
if ( self::IMAGES & $what_to_extract ) {
$extracted = self::get_image_fields( $post, array(), $extract_alt_text );
// Turn off images so we can safely call extract_from_content() below.
$what_to_extract = $what_to_extract - self::IMAGES;
}
if ( function_exists( 'restore_current_blog' ) ) {
restore_current_blog();
}
// All of the other things besides images can be extracted from just the content.
$extracted = self::extract_from_content( $content, $what_to_extract, $extracted );
return $extracted;
}
/**
* Gets the specified meta info from the given post content.
* NOTE: If you want IMAGES, call extract( $blog_id, $post_id, ...) which will give you more/better image extraction
* This method will give you an error if you ask for IMAGES.
*
* @param string $content The HTML post_content of a post.
* @param int $what_to_extract A mask of things to extract, e.g. Jetpack_Media_Meta_Extractor::IMAGES | Jetpack_Media_Meta_Extractor::MENTIONS.
* @param array $already_extracted Previously extracted things, e.g. images from extract(), which can be used for x-referencing here.
*
* @return array a structure containing metadata about the embedded things, or empty array if nothing found, or WP_Error on error.
*/
public static function extract_from_content( $content, $what_to_extract = self::ALL, $already_extracted = array() ) {
$stripped_content = self::get_stripped_content( $content );
// Maybe start with some previously extracted things (e.g. images from extract().
$extracted = $already_extracted;
// Embedded media objects will have already been converted to shortcodes by pre_kses hooks on save.
if ( self::IMAGES & $what_to_extract ) {
$images = self::extract_images_from_content( $stripped_content, array() );
$extracted = array_merge( $extracted, $images );
}
// ----------------------------------- MENTIONS ------------------------------
if ( self::MENTIONS & $what_to_extract ) {
if ( preg_match_all( '/(^|\s)@(\w+)/u', $stripped_content, $matches ) ) {
$mentions = array_values( array_unique( $matches[2] ) ); // array_unique() retains the keys!
$mentions = array_map( 'strtolower', $mentions );
$extracted['mention'] = array( 'name' => $mentions );
if ( ! isset( $extracted['has'] ) ) {
$extracted['has'] = array();
}
$extracted['has']['mention'] = count( $mentions );
}
}
// ----------------------------------- HASHTAGS ------------------------------
/**
* Some hosts may not compile with --enable-unicode-properties and kick a warning:
* Warning: preg_match_all() [function.preg-match-all]: Compilation failed: support for \P, \p, and \X has not been compiled
* Therefore, we only run this code block on wpcom, not in Jetpack.
*/
if ( ( defined( 'IS_WPCOM' ) && IS_WPCOM ) && ( self::HASHTAGS & $what_to_extract ) ) {
// This regex does not exactly match Twitter's
// if there are problems/complaints we should implement this:
// https://github.com/twitter/twitter-text/blob/master/java/src/com/twitter/Regex.java .
if ( preg_match_all( '/(?:^|\s)#(\w*\p{L}+\w*)/u', $stripped_content, $matches ) ) {
$hashtags = array_values( array_unique( $matches[1] ) ); // array_unique() retains the keys!
$hashtags = array_map( 'strtolower', $hashtags );
$extracted['hashtag'] = array( 'name' => $hashtags );
if ( ! isset( $extracted['has'] ) ) {
$extracted['has'] = array();
}
$extracted['has']['hashtag'] = count( $hashtags );
}
}
// ----------------------------------- SHORTCODES ------------------------------
// Always look for shortcodes.
// If we don't want them, we'll just remove them, so we don't grab them as links below.
$shortcode_pattern = '/' . get_shortcode_regex() . '/s';
if ( preg_match_all( $shortcode_pattern, $content, $matches ) ) {
$shortcode_total_count = 0;
$shortcode_type_counts = array();
$shortcode_types = array();
$shortcode_details = array();
if ( self::SHORTCODES & $what_to_extract ) {
foreach ( $matches[2] as $key => $shortcode ) {
// Elasticsearch (and probably other things) doesn't deal well with some chars as key names.
$shortcode_name = preg_replace( '/[.,*"\'\/\\\\#+ ]/', '_', $shortcode );
$attr = shortcode_parse_atts( $matches[3][ $key ] );
$shortcode_total_count++;
if ( ! isset( $shortcode_type_counts[ $shortcode_name ] ) ) {
$shortcode_type_counts[ $shortcode_name ] = 0;
}
$shortcode_type_counts[ $shortcode_name ]++;
// Store (uniquely) presence of all shortcode regardless of whether it's a keeper (for those, get ID below)
// @todo Store number of occurrences?
if ( ! in_array( $shortcode_name, $shortcode_types, true ) ) {
$shortcode_types[] = $shortcode_name;
}
// For keeper shortcodes, also store the id/url of the object (e.g. youtube video, TED talk, etc.).
if ( in_array( $shortcode, self::$keeper_shortcodes, true ) ) {
// Clear shortcode ID data left from the last shortcode.
$id = null;
// We'll try to get the salient ID from the function jetpack_shortcode_get_xyz_id().
// If the shortcode is a class, we'll call XyzShortcode::get_xyz_id().
$shortcode_get_id_func = "jetpack_shortcode_get_{$shortcode}_id";
$shortcode_class_name = ucfirst( $shortcode ) . 'Shortcode';
$shortcode_get_id_method = "get_{$shortcode}_id";
if ( function_exists( $shortcode_get_id_func ) ) {
$id = call_user_func( $shortcode_get_id_func, $attr );
} elseif ( method_exists( $shortcode_class_name, $shortcode_get_id_method ) ) {
$id = call_user_func( array( $shortcode_class_name, $shortcode_get_id_method ), $attr );
}
if ( ! empty( $id )
&& ( ! isset( $shortcode_details[ $shortcode_name ] ) || ! in_array( $id, $shortcode_details[ $shortcode_name ], true ) ) ) {
$shortcode_details[ $shortcode_name ][] = $id;
}
}
}
if ( $shortcode_total_count > 0 ) {
// Add the shortcode info to the $extracted array.
if ( ! isset( $extracted['has'] ) ) {
$extracted['has'] = array();
}
$extracted['has']['shortcode'] = $shortcode_total_count;
$extracted['shortcode'] = array();
foreach ( $shortcode_type_counts as $type => $count ) {
$extracted['shortcode'][ $type ] = array( 'count' => $count );
}
if ( ! empty( $shortcode_types ) ) {
$extracted['shortcode_types'] = $shortcode_types;
}
foreach ( $shortcode_details as $type => $id ) {
$extracted['shortcode'][ $type ]['id'] = $id;
}
}
}
// Remove the shortcodes form our copy of $content, so we don't count links in them as links below.
$content = preg_replace( $shortcode_pattern, ' ', $content );
}
// ----------------------------------- LINKS ------------------------------
if ( self::LINKS & $what_to_extract ) {
// To hold the extracted stuff we find.
$links = array();
// @todo Get the text inside the links?
// Grab any links, whether in <a href="..." or not, but subtract those from shortcodes and images.
// (we treat embed links as just another link).
if ( preg_match_all( '#(?:^|\s|"|\')(https?://([^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/))))#', $content, $matches ) ) {
foreach ( $matches[1] as $link_raw ) {
$url = wp_parse_url( $link_raw );
// Data URI links.
if ( ! isset( $url['scheme'] ) || 'data' === $url['scheme'] ) {
continue;
}
// Reject invalid URLs.
if ( ! isset( $url['host'] ) ) {
continue;
}
// Remove large (and likely invalid) links.
if ( 4096 < strlen( $link_raw ) ) {
continue;
}
// Build a simple form of the URL so we can compare it to ones we found in IMAGES or SHORTCODES and exclude those.
$simple_url = $url['scheme'] . '://' . $url['host'] . ( ! empty( $url['path'] ) ? $url['path'] : '' );
if ( isset( $extracted['image']['url'] ) ) {
if ( in_array( $simple_url, (array) $extracted['image']['url'], true ) ) {
continue;
}
}
list( $proto, $link_all_but_proto ) = explode( '://', $link_raw ); // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
// Build a reversed hostname.
$host_parts = array_reverse( explode( '.', $url['host'] ) );
$host_reversed = '';
foreach ( $host_parts as $part ) {
$host_reversed .= ( ! empty( $host_reversed ) ? '.' : '' ) . $part;
}
$link_analyzed = '';
if ( ! empty( $url['path'] ) ) {
// The whole path (no query args or fragments).
$path = substr( $url['path'], 1 ); // strip the leading '/'.
$link_analyzed .= ( ! empty( $link_analyzed ) ? ' ' : '' ) . $path;
// The path split by /.
$path_split = explode( '/', $path );
if ( count( $path_split ) > 1 ) {
$link_analyzed .= ' ' . implode( ' ', $path_split );
}
// The fragment.
if ( ! empty( $url['fragment'] ) ) {
$link_analyzed .= ( ! empty( $link_analyzed ) ? ' ' : '' ) . $url['fragment'];
}
}
// @todo Check unique before adding
$links[] = array(
'url' => $link_all_but_proto,
'host_reversed' => $host_reversed,
'host' => $url['host'],
);
}
}
$link_count = count( $links );
if ( $link_count ) {
$extracted['link'] = $links;
if ( ! isset( $extracted['has'] ) ) {
$extracted['has'] = array();
}
$extracted['has']['link'] = $link_count;
}
}
// ----------------------------------- EMBEDS ------------------------------
// Embeds are just individual links on their own line.
if ( self::EMBEDS & $what_to_extract ) {
if ( ! function_exists( '_wp_oembed_get_object' ) ) {
include ABSPATH . WPINC . '/class-oembed.php';
}
// get an oembed object.
$oembed = _wp_oembed_get_object();
// Grab any links on their own lines that may be embeds.
if ( preg_match_all( '|^\s*(https?://[^\s"]+)\s*$|im', $content, $matches ) ) {
// To hold the extracted stuff we find.
$embeds = array();
foreach ( $matches[1] as $link_raw ) {
$url = wp_parse_url( $link_raw );
list( $proto, $link_all_but_proto ) = explode( '://', $link_raw ); // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
// Check whether this "link" is really an embed.
foreach ( $oembed->providers as $matchmask => $data ) {
list( $providerurl, $regex ) = $data; // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
// Turn the asterisk-type provider URLs into regex.
if ( ! $regex ) {
$matchmask = '#' . str_replace( '___wildcard___', '(.+)', preg_quote( str_replace( '*', '___wildcard___', $matchmask ), '#' ) ) . '#i';
$matchmask = preg_replace( '|^#http\\\://|', '#https?\://', $matchmask );
}
if ( preg_match( $matchmask, $link_raw ) ) {
$embeds[] = $link_all_but_proto; // @todo Check unique before adding
// @todo Try to get ID's for the ones we care about (shortcode_keepers)
break;
}
}
}
if ( ! empty( $embeds ) ) {
if ( ! isset( $extracted['has'] ) ) {
$extracted['has'] = array();
}
$extracted['has']['embed'] = count( $embeds );
$extracted['embed'] = array( 'url' => array() );
foreach ( $embeds as $e ) {
$extracted['embed']['url'][] = $e;
}
}
}
}
return $extracted;
}
/**
* Get image fields for matching images.
*
* @uses Jetpack_PostImages
*
* @param WP_Post $post A post object.
* @param array $args Optional args, see defaults list for details.
* @param boolean $extract_alt_text Should alt_text be extracted, defaults to false.
*
* @return array Returns an array of all images meeting the specified criteria in $args.
*/
private static function get_image_fields( $post, $args = array(), $extract_alt_text = false ) {
if ( ! $post instanceof WP_Post ) {
return array();
}
$defaults = array(
'width' => 200, // Required minimum width (if possible to determine).
'height' => 200, // Required minimum height (if possible to determine).
);
$args = wp_parse_args( $args, $defaults );
$image_list = array();
$image_booleans = array();
$image_booleans['gallery'] = 0;
$from_featured_image = Jetpack_PostImages::from_thumbnail( $post->ID, $args['width'], $args['height'] );
if ( ! empty( $from_featured_image ) ) {
if ( $extract_alt_text ) {
$image_list = array_merge( $image_list, self::reduce_extracted_images( $from_featured_image ) );
} else {
$srcs = wp_list_pluck( $from_featured_image, 'src' );
$image_list = array_merge( $image_list, $srcs );
}
}
$from_slideshow = Jetpack_PostImages::from_slideshow( $post->ID, $args['width'], $args['height'] );
if ( ! empty( $from_slideshow ) ) {
if ( $extract_alt_text ) {
$image_list = array_merge( $image_list, self::reduce_extracted_images( $from_slideshow ) );
} else {
$srcs = wp_list_pluck( $from_slideshow, 'src' );
$image_list = array_merge( $image_list, $srcs );
}
}
$from_gallery = Jetpack_PostImages::from_gallery( $post->ID );
if ( ! empty( $from_gallery ) ) {
if ( $extract_alt_text ) {
$image_list = array_merge( $image_list, self::reduce_extracted_images( $from_gallery ) );
} else {
$srcs = wp_list_pluck( $from_gallery, 'src' );
$image_list = array_merge( $image_list, $srcs );
}
$image_booleans['gallery']++; // @todo This count isn't correct, will only every count 1
}
// @todo Can we check width/height of these efficiently? Could maybe use query args at least, before we strip them out
$image_list = self::get_images_from_html( $post->post_content, $image_list, $extract_alt_text );
return self::build_image_struct( $image_list, $image_booleans );
}
/**
* Given an extracted image array reduce to src and alt_text.
*
* @param array $images extracted image array.
*
* @return array reduced image array
*/
protected static function reduce_extracted_images( $images ) {
$ret_images = array();
foreach ( $images as $image ) {
// skip if src isn't set.
if ( empty( $image['src'] ) ) {
continue;
}
if ( ! empty( $image['alt_text'] ) ) {
$ret_images[] = array(
'url' => $image['src'],
'alt_text' => $image['alt_text'],
);
} else {
$ret_images[] = $image['src'];
}
}
return $ret_images;
}
/**
* Helper function to get images from HTML and return it with the set sturcture.
*
* @param string $content HTML content.
* @param array $image_list Array of already found images.
*
* @return array|array[] Array of images.
*/
public static function extract_images_from_content( $content, $image_list ) {
$image_list = self::get_images_from_html( $content, $image_list );
return self::build_image_struct( $image_list, array() );
}
/**
* Produces a set structure for extracted media items.
*
* @param array $image_list Array of images.
* @param array $image_booleans Image booleans.
*
* @return array|array[]
*/
public static function build_image_struct( $image_list, $image_booleans ) {
if ( ! empty( $image_list ) ) {
$retval = array( 'image' => array() );
$image_list = array_unique( $image_list, SORT_REGULAR );
foreach ( $image_list as $img ) {
if ( is_string( $img ) ) {
$retval['image'][] = array( 'url' => $img );
} else {
$retval['image'][] = $img;
}
}
$image_booleans['image'] = count( $retval['image'] );
if ( ! empty( $image_booleans ) ) {
$retval['has'] = $image_booleans;
}
return $retval;
} else {
return array();
}
}
/**
* Extracts images from html.
*
* @param string $html Some markup, possibly containing image tags.
* @param array $images_already_extracted (just an array of image URLs without query strings, no special structure), used for de-duplication.
* @param boolean $extract_alt_text Should alt_text be extracted, defaults to false.
*
* @return array Image URLs extracted from the HTML, stripped of query params and de-duped
*/
public static function get_images_from_html( $html, $images_already_extracted, $extract_alt_text = false ) {
$image_list = $images_already_extracted;
$from_html = Jetpack_PostImages::from_html( $html );
// early return if no image in html.
if ( empty( $from_html ) ) {
return $image_list;
}
// process images.
foreach ( $from_html as $extracted_image ) {
$image_url = $extracted_image['src'];
$length = strpos( $image_url, '?' );
$src = wp_parse_url( $image_url );
if ( $src && isset( $src['scheme'], $src['host'], $src['path'] ) ) {
// Rebuild the URL without the query string.
$queryless = $src['scheme'] . '://' . $src['host'] . $src['path'];
} elseif ( $length ) {
// If wp_parse_url() didn't work, strip off the query string the old fashioned way.
$queryless = substr( $image_url, 0, $length );
} else {
// Failing that, there was no spoon! Err ... query string!
$queryless = $image_url;
}
// Discard URLs that are longer then 4KB, these are likely data URIs or malformed HTML.
if ( 4096 < strlen( $queryless ) ) {
continue;
}
if ( ! in_array( $queryless, $image_list, true ) ) {
if ( $extract_alt_text && ! empty( $extracted_image['alt_text'] ) ) {
$image_list[] = array(
'url' => $queryless,
'alt_text' => $extracted_image['alt_text'],
);
} else {
$image_list[] = $queryless;
}
}
}
return $image_list;
}
/**
* Strips concents of all tags, shortcodes, and decodes HTML entities.
*
* @param string $content Original content.
*
* @return string Cleaned content.
*/
private static function get_stripped_content( $content ) {
$clean_content = wp_strip_all_tags( $content );
$clean_content = html_entity_decode( $clean_content );
// completely strip shortcodes and any content they enclose.
$clean_content = strip_shortcodes( $clean_content );
return $clean_content;
}
}