669 lines
20 KiB
PHP
669 lines
20 KiB
PHP
|
<?php
|
||
|
|
/**
|
||
|
|
* REST API: WP_REST_URL_Details_Controller class
|
||
|
|
*
|
||
|
|
* @package WordPress
|
||
|
|
* @subpackage REST_API
|
||
|
|
* @since 5.9.0
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Controller which provides REST endpoint for retrieving information
|
||
|
|
* from a remote site's HTML response.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @see WP_REST_Controller
|
||
|
|
*/
|
||
|
|
class WP_REST_URL_Details_Controller extends WP_REST_Controller {
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Constructs the controller.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*/
|
||
|
|
public function __construct() {
|
||
|
|
$this->namespace = 'wp-block-editor/v1';
|
||
|
|
$this->rest_base = 'url-details';
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Registers the necessary REST API routes.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*/
|
||
|
|
public function register_routes() {
|
||
|
|
register_rest_route(
|
||
|
|
$this->namespace,
|
||
|
|
'/' . $this->rest_base,
|
||
|
|
array(
|
||
|
|
array(
|
||
|
|
'methods' => WP_REST_Server::READABLE,
|
||
|
|
'callback' => array( $this, 'parse_url_details' ),
|
||
|
|
'args' => array(
|
||
|
|
'url' => array(
|
||
|
|
'required' => true,
|
||
|
|
'description' => __( 'The URL to process.' ),
|
||
|
|
'validate_callback' => 'wp_http_validate_url',
|
||
|
|
'sanitize_callback' => 'sanitize_url',
|
||
|
|
'type' => 'string',
|
||
|
|
'format' => 'uri',
|
||
|
|
),
|
||
|
|
),
|
||
|
|
'permission_callback' => array( $this, 'permissions_check' ),
|
||
|
|
'schema' => array( $this, 'get_public_item_schema' ),
|
||
|
|
),
|
||
|
|
)
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Retrieves the item's schema, conforming to JSON Schema.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @return array Item schema data.
|
||
|
|
*/
|
||
|
|
public function get_item_schema() {
|
||
|
|
if ( $this->schema ) {
|
||
|
|
return $this->add_additional_fields_schema( $this->schema );
|
||
|
|
}
|
||
|
|
|
||
|
|
$this->schema = array(
|
||
|
|
'$schema' => 'http://json-schema.org/draft-04/schema#',
|
||
|
|
'title' => 'url-details',
|
||
|
|
'type' => 'object',
|
||
|
|
'properties' => array(
|
||
|
|
'title' => array(
|
||
|
|
'description' => sprintf(
|
||
|
|
/* translators: %s: HTML title tag. */
|
||
|
|
__( 'The contents of the %s element from the URL.' ),
|
||
|
|
'<title>'
|
||
|
|
),
|
||
|
|
'type' => 'string',
|
||
|
|
'context' => array( 'view', 'edit', 'embed' ),
|
||
|
|
'readonly' => true,
|
||
|
|
),
|
||
|
|
'icon' => array(
|
||
|
|
'description' => sprintf(
|
||
|
|
/* translators: %s: HTML link tag. */
|
||
|
|
__( 'The favicon image link of the %s element from the URL.' ),
|
||
|
|
'<link rel="icon">'
|
||
|
|
),
|
||
|
|
'type' => 'string',
|
||
|
|
'format' => 'uri',
|
||
|
|
'context' => array( 'view', 'edit', 'embed' ),
|
||
|
|
'readonly' => true,
|
||
|
|
),
|
||
|
|
'description' => array(
|
||
|
|
'description' => sprintf(
|
||
|
|
/* translators: %s: HTML meta tag. */
|
||
|
|
__( 'The content of the %s element from the URL.' ),
|
||
|
|
'<meta name="description">'
|
||
|
|
),
|
||
|
|
'type' => 'string',
|
||
|
|
'context' => array( 'view', 'edit', 'embed' ),
|
||
|
|
'readonly' => true,
|
||
|
|
),
|
||
|
|
'image' => array(
|
||
|
|
'description' => sprintf(
|
||
|
|
/* translators: 1: HTML meta tag, 2: HTML meta tag. */
|
||
|
|
__( 'The Open Graph image link of the %1$s or %2$s element from the URL.' ),
|
||
|
|
'<meta property="og:image">',
|
||
|
|
'<meta property="og:image:url">'
|
||
|
|
),
|
||
|
|
'type' => 'string',
|
||
|
|
'format' => 'uri',
|
||
|
|
'context' => array( 'view', 'edit', 'embed' ),
|
||
|
|
'readonly' => true,
|
||
|
|
),
|
||
|
|
),
|
||
|
|
);
|
||
|
|
|
||
|
|
return $this->add_additional_fields_schema( $this->schema );
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Retrieves the contents of the title tag from the HTML response.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param WP_REST_Request $request Full details about the request.
|
||
|
|
* @return WP_REST_Response|WP_Error The parsed details as a response object. WP_Error if there are errors.
|
||
|
|
*/
|
||
|
|
public function parse_url_details( $request ) {
|
||
|
|
$url = untrailingslashit( $request['url'] );
|
||
|
|
|
||
|
|
if ( empty( $url ) ) {
|
||
|
|
return new WP_Error( 'rest_invalid_url', __( 'Invalid URL' ), array( 'status' => 404 ) );
|
||
|
|
}
|
||
|
|
|
||
|
|
// Transient per URL.
|
||
|
|
$cache_key = $this->build_cache_key_for_url( $url );
|
||
|
|
|
||
|
|
// Attempt to retrieve cached response.
|
||
|
|
$cached_response = $this->get_cache( $cache_key );
|
||
|
|
|
||
|
|
if ( ! empty( $cached_response ) ) {
|
||
|
|
$remote_url_response = $cached_response;
|
||
|
|
} else {
|
||
|
|
$remote_url_response = $this->get_remote_url( $url );
|
||
|
|
|
||
|
|
// Exit if we don't have a valid body or it's empty.
|
||
|
|
if ( is_wp_error( $remote_url_response ) || empty( $remote_url_response ) ) {
|
||
|
|
return $remote_url_response;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Cache the valid response.
|
||
|
|
$this->set_cache( $cache_key, $remote_url_response );
|
||
|
|
}
|
||
|
|
|
||
|
|
$html_head = $this->get_document_head( $remote_url_response );
|
||
|
|
$meta_elements = $this->get_meta_with_content_elements( $html_head );
|
||
|
|
|
||
|
|
$data = $this->add_additional_fields_to_object(
|
||
|
|
array(
|
||
|
|
'title' => $this->get_title( $html_head ),
|
||
|
|
'icon' => $this->get_icon( $html_head, $url ),
|
||
|
|
'description' => $this->get_description( $meta_elements ),
|
||
|
|
'image' => $this->get_image( $meta_elements, $url ),
|
||
|
|
),
|
||
|
|
$request
|
||
|
|
);
|
||
|
|
|
||
|
|
// Wrap the data in a response object.
|
||
|
|
$response = rest_ensure_response( $data );
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Filters the URL data for the response.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param WP_REST_Response $response The response object.
|
||
|
|
* @param string $url The requested URL.
|
||
|
|
* @param WP_REST_Request $request Request object.
|
||
|
|
* @param string $remote_url_response HTTP response body from the remote URL.
|
||
|
|
*/
|
||
|
|
return apply_filters( 'rest_prepare_url_details', $response, $url, $request, $remote_url_response );
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Checks whether a given request has permission to read remote URLs.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @return WP_Error|bool True if the request has permission, else WP_Error.
|
||
|
|
*/
|
||
|
|
public function permissions_check() {
|
||
|
|
if ( current_user_can( 'edit_posts' ) ) {
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
|
||
|
|
if ( current_user_can( $post_type->cap->edit_posts ) ) {
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return new WP_Error(
|
||
|
|
'rest_cannot_view_url_details',
|
||
|
|
__( 'Sorry, you are not allowed to process remote URLs.' ),
|
||
|
|
array( 'status' => rest_authorization_required_code() )
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Retrieves the document title from a remote URL.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $url The website URL whose HTML to access.
|
||
|
|
* @return string|WP_Error The HTTP response from the remote URL on success.
|
||
|
|
* WP_Error if no response or no content.
|
||
|
|
*/
|
||
|
|
private function get_remote_url( $url ) {
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Provide a modified UA string to workaround web properties which block WordPress "Pingbacks".
|
||
|
|
* Why? The UA string used for pingback requests contains `WordPress/` which is very similar
|
||
|
|
* to that used as the default UA string by the WP HTTP API. Therefore requests from this
|
||
|
|
* REST endpoint are being unintentionally blocked as they are misidentified as pingback requests.
|
||
|
|
* By slightly modifying the UA string, but still retaining the "WordPress" identification (via "WP")
|
||
|
|
* we are able to work around this issue.
|
||
|
|
* Example UA string: `WP-URLDetails/5.9-alpha-51389 (+http://localhost:8888)`.
|
||
|
|
*/
|
||
|
|
$modified_user_agent = 'WP-URLDetails/' . get_bloginfo( 'version' ) . ' (+' . get_bloginfo( 'url' ) . ')';
|
||
|
|
|
||
|
|
$args = array(
|
||
|
|
'limit_response_size' => 150 * KB_IN_BYTES,
|
||
|
|
'user-agent' => $modified_user_agent,
|
||
|
|
);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Filters the HTTP request args for URL data retrieval.
|
||
|
|
*
|
||
|
|
* Can be used to adjust response size limit and other WP_Http::request() args.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param array $args Arguments used for the HTTP request.
|
||
|
|
* @param string $url The attempted URL.
|
||
|
|
*/
|
||
|
|
$args = apply_filters( 'rest_url_details_http_request_args', $args, $url );
|
||
|
|
|
||
|
|
$response = wp_safe_remote_get( $url, $args );
|
||
|
|
|
||
|
|
if ( WP_Http::OK !== wp_remote_retrieve_response_code( $response ) ) {
|
||
|
|
// Not saving the error response to cache since the error might be temporary.
|
||
|
|
return new WP_Error(
|
||
|
|
'no_response',
|
||
|
|
__( 'URL not found. Response returned a non-200 status code for this URL.' ),
|
||
|
|
array( 'status' => WP_Http::NOT_FOUND )
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
$remote_body = wp_remote_retrieve_body( $response );
|
||
|
|
|
||
|
|
if ( empty( $remote_body ) ) {
|
||
|
|
return new WP_Error(
|
||
|
|
'no_content',
|
||
|
|
__( 'Unable to retrieve body from response at this URL.' ),
|
||
|
|
array( 'status' => WP_Http::NOT_FOUND )
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
return $remote_body;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Parses the title tag contents from the provided HTML.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $html The HTML from the remote website at URL.
|
||
|
|
* @return string The title tag contents on success. Empty string if not found.
|
||
|
|
*/
|
||
|
|
private function get_title( $html ) {
|
||
|
|
$pattern = '#<title[^>]*>(.*?)<\s*/\s*title>#is';
|
||
|
|
preg_match( $pattern, $html, $match_title );
|
||
|
|
|
||
|
|
if ( empty( $match_title[1] ) || ! is_string( $match_title[1] ) ) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
|
||
|
|
$title = trim( $match_title[1] );
|
||
|
|
|
||
|
|
return $this->prepare_metadata_for_output( $title );
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Parses the site icon from the provided HTML.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $html The HTML from the remote website at URL.
|
||
|
|
* @param string $url The target website URL.
|
||
|
|
* @return string The icon URI on success. Empty string if not found.
|
||
|
|
*/
|
||
|
|
private function get_icon( $html, $url ) {
|
||
|
|
// Grab the icon's link element.
|
||
|
|
$pattern = '#<link\s[^>]*rel=(?:[\"\']??)\s*(?:icon|shortcut icon|icon shortcut)\s*(?:[\"\']??)[^>]*\/?>#isU';
|
||
|
|
preg_match( $pattern, $html, $element );
|
||
|
|
if ( empty( $element[0] ) || ! is_string( $element[0] ) ) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
$element = trim( $element[0] );
|
||
|
|
|
||
|
|
// Get the icon's href value.
|
||
|
|
$pattern = '#href=([\"\']??)([^\" >]*?)\\1[^>]*#isU';
|
||
|
|
preg_match( $pattern, $element, $icon );
|
||
|
|
if ( empty( $icon[2] ) || ! is_string( $icon[2] ) ) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
$icon = trim( $icon[2] );
|
||
|
|
|
||
|
|
// If the icon is a data URL, return it.
|
||
|
|
$parsed_icon = parse_url( $icon );
|
||
|
|
if ( isset( $parsed_icon['scheme'] ) && 'data' === $parsed_icon['scheme'] ) {
|
||
|
|
return $icon;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Attempt to convert relative URLs to absolute.
|
||
|
|
if ( ! is_string( $url ) || '' === $url ) {
|
||
|
|
return $icon;
|
||
|
|
}
|
||
|
|
$parsed_url = parse_url( $url );
|
||
|
|
if ( isset( $parsed_url['scheme'] ) && isset( $parsed_url['host'] ) ) {
|
||
|
|
$root_url = $parsed_url['scheme'] . '://' . $parsed_url['host'] . '/';
|
||
|
|
$icon = WP_Http::make_absolute_url( $icon, $root_url );
|
||
|
|
}
|
||
|
|
|
||
|
|
return $icon;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Parses the meta description from the provided HTML.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param array $meta_elements {
|
||
|
|
* A multi-dimensional indexed array on success, else empty array.
|
||
|
|
*
|
||
|
|
* @type string[] $0 Meta elements with a content attribute.
|
||
|
|
* @type string[] $1 Content attribute's opening quotation mark.
|
||
|
|
* @type string[] $2 Content attribute's value for each meta element.
|
||
|
|
* }
|
||
|
|
* @return string The meta description contents on success. Empty string if not found.
|
||
|
|
*/
|
||
|
|
private function get_description( $meta_elements ) {
|
||
|
|
// Bail out if there are no meta elements.
|
||
|
|
if ( empty( $meta_elements[0] ) ) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
|
||
|
|
$description = $this->get_metadata_from_meta_element(
|
||
|
|
$meta_elements,
|
||
|
|
'name',
|
||
|
|
'(?:description|og:description)'
|
||
|
|
);
|
||
|
|
|
||
|
|
// Bail out if description not found.
|
||
|
|
if ( '' === $description ) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
|
||
|
|
return $this->prepare_metadata_for_output( $description );
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Parses the Open Graph (OG) Image from the provided HTML.
|
||
|
|
*
|
||
|
|
* See: https://ogp.me/.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param array $meta_elements {
|
||
|
|
* A multi-dimensional indexed array on success, else empty array.
|
||
|
|
*
|
||
|
|
* @type string[] $0 Meta elements with a content attribute.
|
||
|
|
* @type string[] $1 Content attribute's opening quotation mark.
|
||
|
|
* @type string[] $2 Content attribute's value for each meta element.
|
||
|
|
* }
|
||
|
|
* @param string $url The target website URL.
|
||
|
|
* @return string The OG image on success. Empty string if not found.
|
||
|
|
*/
|
||
|
|
private function get_image( $meta_elements, $url ) {
|
||
|
|
$image = $this->get_metadata_from_meta_element(
|
||
|
|
$meta_elements,
|
||
|
|
'property',
|
||
|
|
'(?:og:image|og:image:url)'
|
||
|
|
);
|
||
|
|
|
||
|
|
// Bail out if image not found.
|
||
|
|
if ( '' === $image ) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
|
||
|
|
// Attempt to convert relative URLs to absolute.
|
||
|
|
$parsed_url = parse_url( $url );
|
||
|
|
if ( isset( $parsed_url['scheme'] ) && isset( $parsed_url['host'] ) ) {
|
||
|
|
$root_url = $parsed_url['scheme'] . '://' . $parsed_url['host'] . '/';
|
||
|
|
$image = WP_Http::make_absolute_url( $image, $root_url );
|
||
|
|
}
|
||
|
|
|
||
|
|
return $image;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Prepares the metadata by:
|
||
|
|
* - stripping all HTML tags and tag entities.
|
||
|
|
* - converting non-tag entities into characters.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $metadata The metadata content to prepare.
|
||
|
|
* @return string The prepared metadata.
|
||
|
|
*/
|
||
|
|
private function prepare_metadata_for_output( $metadata ) {
|
||
|
|
$metadata = html_entity_decode( $metadata, ENT_QUOTES, get_bloginfo( 'charset' ) );
|
||
|
|
$metadata = wp_strip_all_tags( $metadata );
|
||
|
|
return $metadata;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Utility function to build cache key for a given URL.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $url The URL for which to build a cache key.
|
||
|
|
* @return string The cache key.
|
||
|
|
*/
|
||
|
|
private function build_cache_key_for_url( $url ) {
|
||
|
|
return 'g_url_details_response_' . md5( $url );
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Utility function to retrieve a value from the cache at a given key.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $key The cache key.
|
||
|
|
* @return mixed The value from the cache.
|
||
|
|
*/
|
||
|
|
private function get_cache( $key ) {
|
||
|
|
return get_site_transient( $key );
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Utility function to cache a given data set at a given cache key.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $key The cache key under which to store the value.
|
||
|
|
* @param string $data The data to be stored at the given cache key.
|
||
|
|
* @return bool True when transient set. False if not set.
|
||
|
|
*/
|
||
|
|
private function set_cache( $key, $data = '' ) {
|
||
|
|
$ttl = HOUR_IN_SECONDS;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Filters the cache expiration.
|
||
|
|
*
|
||
|
|
* Can be used to adjust the time until expiration in seconds for the cache
|
||
|
|
* of the data retrieved for the given URL.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param int $ttl The time until cache expiration in seconds.
|
||
|
|
*/
|
||
|
|
$cache_expiration = apply_filters( 'rest_url_details_cache_expiration', $ttl );
|
||
|
|
|
||
|
|
return set_site_transient( $key, $data, $cache_expiration );
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Retrieves the head element section.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $html The string of HTML to parse.
|
||
|
|
* @return string The `<head>..</head>` section on success. Given `$html` if not found.
|
||
|
|
*/
|
||
|
|
private function get_document_head( $html ) {
|
||
|
|
$head_html = $html;
|
||
|
|
|
||
|
|
// Find the opening `<head>` tag.
|
||
|
|
$head_start = strpos( $html, '<head' );
|
||
|
|
if ( false === $head_start ) {
|
||
|
|
// Didn't find it. Return the original HTML.
|
||
|
|
return $html;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Find the closing `</head>` tag.
|
||
|
|
$head_end = strpos( $head_html, '</head>' );
|
||
|
|
if ( false === $head_end ) {
|
||
|
|
// Didn't find it. Find the opening `<body>` tag.
|
||
|
|
$head_end = strpos( $head_html, '<body' );
|
||
|
|
|
||
|
|
// Didn't find it. Return the original HTML.
|
||
|
|
if ( false === $head_end ) {
|
||
|
|
return $html;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Extract the HTML from opening tag to the closing tag. Then add the closing tag.
|
||
|
|
$head_html = substr( $head_html, $head_start, $head_end );
|
||
|
|
$head_html .= '</head>';
|
||
|
|
|
||
|
|
return $head_html;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Gets all the meta tag elements that have a 'content' attribute.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param string $html The string of HTML to be parsed.
|
||
|
|
* @return array {
|
||
|
|
* A multi-dimensional indexed array on success, else empty array.
|
||
|
|
*
|
||
|
|
* @type string[] $0 Meta elements with a content attribute.
|
||
|
|
* @type string[] $1 Content attribute's opening quotation mark.
|
||
|
|
* @type string[] $2 Content attribute's value for each meta element.
|
||
|
|
* }
|
||
|
|
*/
|
||
|
|
private function get_meta_with_content_elements( $html ) {
|
||
|
|
/*
|
||
|
|
* Parse all meta elements with a content attribute.
|
||
|
|
*
|
||
|
|
* Why first search for the content attribute rather than directly searching for name=description element?
|
||
|
|
* tl;dr The content attribute's value will be truncated when it contains a > symbol.
|
||
|
|
*
|
||
|
|
* The content attribute's value (i.e. the description to get) can have HTML in it and be well-formed as
|
||
|
|
* it's a string to the browser. Imagine what happens when attempting to match for the name=description
|
||
|
|
* first. Hmm, if a > or /> symbol is in the content attribute's value, then it terminates the match
|
||
|
|
* as the element's closing symbol. But wait, it's in the content attribute and is not the end of the
|
||
|
|
* element. This is a limitation of using regex. It can't determine "wait a minute this is inside of quotation".
|
||
|
|
* If this happens, what gets matched is not the entire element or all of the content.
|
||
|
|
*
|
||
|
|
* Why not search for the name=description and then content="(.*)"?
|
||
|
|
* The attribute order could be opposite. Plus, additional attributes may exist including being between
|
||
|
|
* the name and content attributes.
|
||
|
|
*
|
||
|
|
* Why not lookahead?
|
||
|
|
* Lookahead is not constrained to stay within the element. The first <meta it finds may not include
|
||
|
|
* the name or content, but rather could be from a different element downstream.
|
||
|
|
*/
|
||
|
|
$pattern = '#<meta\s' .
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Allows for additional attributes before the content attribute.
|
||
|
|
* Searches for anything other than > symbol.
|
||
|
|
*/
|
||
|
|
'[^>]*' .
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Find the content attribute. When found, capture its value (.*).
|
||
|
|
*
|
||
|
|
* Allows for (a) single or double quotes and (b) whitespace in the value.
|
||
|
|
*
|
||
|
|
* Why capture the opening quotation mark, i.e. (["\']), and then backreference,
|
||
|
|
* i.e \1, for the closing quotation mark?
|
||
|
|
* To ensure the closing quotation mark matches the opening one. Why? Attribute values
|
||
|
|
* can contain quotation marks, such as an apostrophe in the content.
|
||
|
|
*/
|
||
|
|
'content=(["\']??)(.*)\1' .
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Allows for additional attributes after the content attribute.
|
||
|
|
* Searches for anything other than > symbol.
|
||
|
|
*/
|
||
|
|
'[^>]*' .
|
||
|
|
|
||
|
|
/*
|
||
|
|
* \/?> searches for the closing > symbol, which can be in either /> or > format.
|
||
|
|
* # ends the pattern.
|
||
|
|
*/
|
||
|
|
'\/?>#' .
|
||
|
|
|
||
|
|
/*
|
||
|
|
* These are the options:
|
||
|
|
* - i : case insensitive
|
||
|
|
* - s : allows newline characters for the . match (needed for multiline elements)
|
||
|
|
* - U means non-greedy matching
|
||
|
|
*/
|
||
|
|
'isU';
|
||
|
|
|
||
|
|
preg_match_all( $pattern, $html, $elements );
|
||
|
|
|
||
|
|
return $elements;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Gets the metadata from a target meta element.
|
||
|
|
*
|
||
|
|
* @since 5.9.0
|
||
|
|
*
|
||
|
|
* @param array $meta_elements {
|
||
|
|
* A multi-dimensional indexed array on success, else empty array.
|
||
|
|
*
|
||
|
|
* @type string[] $0 Meta elements with a content attribute.
|
||
|
|
* @type string[] $1 Content attribute's opening quotation mark.
|
||
|
|
* @type string[] $2 Content attribute's value for each meta element.
|
||
|
|
* }
|
||
|
|
* @param string $attr Attribute that identifies the element with the target metadata.
|
||
|
|
* @param string $attr_value The attribute's value that identifies the element with the target metadata.
|
||
|
|
* @return string The metadata on success. Empty string if not found.
|
||
|
|
*/
|
||
|
|
private function get_metadata_from_meta_element( $meta_elements, $attr, $attr_value ) {
|
||
|
|
// Bail out if there are no meta elements.
|
||
|
|
if ( empty( $meta_elements[0] ) ) {
|
||
|
|
return '';
|
||
|
|
}
|
||
|
|
|
||
|
|
$metadata = '';
|
||
|
|
$pattern = '#' .
|
||
|
|
/*
|
||
|
|
* Target this attribute and value to find the metadata element.
|
||
|
|
*
|
||
|
|
* Allows for (a) no, single, double quotes and (b) whitespace in the value.
|
||
|
|
*
|
||
|
|
* Why capture the opening quotation mark, i.e. (["\']), and then backreference,
|
||
|
|
* i.e \1, for the closing quotation mark?
|
||
|
|
* To ensure the closing quotation mark matches the opening one. Why? Attribute values
|
||
|
|
* can contain quotation marks, such as an apostrophe in the content.
|
||
|
|
*/
|
||
|
|
$attr . '=([\"\']??)\s*' . $attr_value . '\s*\1' .
|
||
|
|
|
||
|
|
/*
|
||
|
|
* These are the options:
|
||
|
|
* - i : case insensitive
|
||
|
|
* - s : allows newline characters for the . match (needed for multiline elements)
|
||
|
|
* - U means non-greedy matching
|
||
|
|
*/
|
||
|
|
'#isU';
|
||
|
|
|
||
|
|
// Find the metadata element.
|
||
|
|
foreach ( $meta_elements[0] as $index => $element ) {
|
||
|
|
preg_match( $pattern, $element, $match );
|
||
|
|
|
||
|
|
// This is not the metadata element. Skip it.
|
||
|
|
if ( empty( $match ) ) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Found the metadata element.
|
||
|
|
* Get the metadata from its matching content array.
|
||
|
|
*/
|
||
|
|
if ( isset( $meta_elements[2][ $index ] ) && is_string( $meta_elements[2][ $index ] ) ) {
|
||
|
|
$metadata = trim( $meta_elements[2][ $index ] );
|
||
|
|
}
|
||
|
|
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return $metadata;
|
||
|
|
}
|
||
|
|
}
|