/** * WP_Theme Class * * @package WordPress * @subpackage Theme */ final class WP_Theme implements ArrayAccess { /** * Headers for style.css files. * * @static * @access private * @var array */ private static $file_headers = array( 'Name' => 'Theme Name', 'ThemeURI' => 'Theme URI', 'Description' => 'Description', 'Author' => 'Author', 'AuthorURI' => 'Author URI', 'Version' => 'Version', 'Template' => 'Template', 'Status' => 'Status', 'Tags' => 'Tags', 'TextDomain' => 'Text Domain', 'DomainPath' => 'Domain Path', ); /** * Default themes. * * @static * @access private * @var array */ private static $default_themes = array( 'classic' => 'WordPress Classic', 'default' => 'WordPress Default', 'twentyten' => 'Twenty Ten', 'twentyeleven' => 'Twenty Eleven', 'twentytwelve' => 'Twenty Twelve', 'twentythirteen' => 'Twenty Thirteen', 'twentyfourteen' => 'Twenty Fourteen', 'twentyfifteen' => 'Twenty Fifteen', ); /** * Renamed theme tags. * * @static * @access private * @var array */ private static $tag_map = array( 'fixed-width' => 'fixed-layout', 'flexible-width' => 'fluid-layout', ); /** * Absolute path to the theme root, usually wp-content/themes * * @access private * @var string */ private $theme_root; /** * Header data from the theme's style.css file. * * @access private * @var array */ private $headers = array(); /** * Header data from the theme's style.css file after being sanitized. * * @access private * @var array */ private $headers_sanitized; /** * Header name from the theme's style.css after being translated. * * Cached due to sorting functions running over the translated name. * * @access private * @var string */ private $name_translated; /** * Errors encountered when initializing the theme. * * @access private * @var WP_Error */ private $errors; /** * The directory name of the theme's files, inside the theme root. * * In the case of a child theme, this is directory name of the child theme. * Otherwise, 'stylesheet' is the same as 'template'. * * @access private * @var string */ private $stylesheet; /** * The directory name of the theme's files, inside the theme root. * * In the case of a child theme, this is the directory name of the parent theme. * Otherwise, 'template' is the same as 'stylesheet'. * * @access private * @var string */ private $template; /** * A reference to the parent theme, in the case of a child theme. * * @access private * @var WP_Theme */ private $parent; /** * URL to the theme root, usually an absolute URL to wp-content/themes * * @access private * var string */ private $theme_root_uri; /** * Flag for whether the theme's textdomain is loaded. * * @access private * @var bool */ private $textdomain_loaded; /** * Stores an md5 hash of the theme root, to function as the cache key. * * @access private * @var string */ private $cache_hash; /** * Flag for whether the themes cache bucket should be persistently cached. * * Default is false. Can be set with the wp_cache_themes_persistently filter. * * @static * @access private * @var bool */ private static $persistently_cache; /** * Expiration time for the themes cache bucket. * * By default the bucket is not cached, so this value is useless. * * @static * @access private * @var bool */ private static $cache_expiration = 1800; /** * Constructor for WP_Theme. * * @global array $wp_theme_directories * * @param string $theme_dir Directory of the theme within the theme_root. * @param string $theme_root Theme root. * @param WP_Error|void $_child If this theme is a parent theme, the child may be passed for validation purposes. */ public function __construct( $theme_dir, $theme_root, $_child = null ) { global $wp_theme_directories; // Initialize caching on first run. if ( ! isset( self::$persistently_cache ) ) { /** This action is documented in wp-includes/theme.php */ self::$persistently_cache = apply_filters( 'wp_cache_themes_persistently', false, 'WP_Theme' ); if ( self::$persistently_cache ) { wp_cache_add_global_groups( 'themes' ); if ( is_int( self::$persistently_cache ) ) self::$cache_expiration = self::$persistently_cache; } else { wp_cache_add_non_persistent_groups( 'themes' ); } } $this->theme_root = $theme_root; $this->stylesheet = $theme_dir; // Correct a situation where the theme is 'some-directory/some-theme' but 'some-directory' was passed in as part of the theme root instead. if ( ! in_array( $theme_root, (array) $wp_theme_directories ) && in_array( dirname( $theme_root ), (array) $wp_theme_directories ) ) { $this->stylesheet = basename( $this->theme_root ) . '/' . $this->stylesheet; $this->theme_root = dirname( $theme_root ); } $this->cache_hash = md5( $this->theme_root . '/' . $this->stylesheet ); $theme_file = $this->stylesheet . '/style.css'; $cache = $this->cache_get( 'theme' ); if ( is_array( $cache ) ) { foreach ( array( 'errors', 'headers', 'template' ) as $key ) { if ( isset( $cache[ $key ] ) ) $this->$key = $cache[ $key ]; } if ( $this->errors ) return; if ( isset( $cache['theme_root_template'] ) ) $theme_root_template = $cache['theme_root_template']; } elseif ( ! file_exists( $this->theme_root . '/' . $theme_file ) ) { $this->headers['Name'] = $this->stylesheet; if ( ! file_exists( $this->theme_root . '/' . $this->stylesheet ) ) $this->errors = new WP_Error( 'theme_not_found', sprintf( __( 'The theme directory "%s" does not exist.' ), esc_html( $this->stylesheet ) ) ); else $this->errors = new WP_Error( 'theme_no_stylesheet', __( 'Stylesheet is missing.' ) ); $this->template = $this->stylesheet; $this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) ); if ( ! file_exists( $this->theme_root ) ) // Don't cache this one. $this->errors->add( 'theme_root_missing', __( 'ERROR: The themes directory is either empty or doesn’t exist. Please check your installation.' ) ); return; } elseif ( ! is_readable( $this->theme_root . '/' . $theme_file ) ) { $this->headers['Name'] = $this->stylesheet; $this->errors = new WP_Error( 'theme_stylesheet_not_readable', __( 'Stylesheet is not readable.' ) ); $this->template = $this->stylesheet; $this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) ); return; } else { $this->headers = get_file_data( $this->theme_root . '/' . $theme_file, self::$file_headers, 'theme' ); // Default themes always trump their pretenders. // Properly identify default themes that are inside a directory within wp-content/themes. if ( $default_theme_slug = array_search( $this->headers['Name'], self::$default_themes ) ) { if ( basename( $this->stylesheet ) != $default_theme_slug ) $this->headers['Name'] .= '/' . $this->stylesheet; } } // (If template is set from cache [and there are no errors], we know it's good.) if ( ! $this->template && ! ( $this->template = $this->headers['Template'] ) ) { $this->template = $this->stylesheet; if ( ! file_exists( $this->theme_root . '/' . $this->stylesheet . '/index.php' ) ) { $this->errors = new WP_Error( 'theme_no_index', __( 'Template is missing.' ) ); $this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) ); return; } } // If we got our data from cache, we can assume that 'template' is pointing to the right place. if ( ! is_array( $cache ) && $this->template != $this->stylesheet && ! file_exists( $this->theme_root . '/' . $this->template . '/index.php' ) ) { // If we're in a directory of themes inside /themes, look for the parent nearby. // wp-content/themes/directory-of-themes/* $parent_dir = dirname( $this->stylesheet ); if ( '.' != $parent_dir && file_exists( $this->theme_root . '/' . $parent_dir . '/' . $this->template . '/index.php' ) ) { $this->template = $parent_dir . '/' . $this->template; } elseif ( ( $directories = search_theme_directories() ) && isset( $directories[ $this->template ] ) ) { // Look for the template in the search_theme_directories() results, in case it is in another theme root. // We don't look into directories of themes, just the theme root. $theme_root_template = $directories[ $this->template ]['theme_root']; } else { // Parent theme is missing. $this->errors = new WP_Error( 'theme_no_parent', sprintf( __( 'The parent theme is missing. Please install the "%s" parent theme.' ), esc_html( $this->template ) ) ); $this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) ); $this->parent = new WP_Theme( $this->template, $this->theme_root, $this ); return; } } // Set the parent, if we're a child theme. if ( $this->template != $this->stylesheet ) { // If we are a parent, then there is a problem. Only two generations allowed! Cancel things out. if ( $_child instanceof WP_Theme && $_child->template == $this->stylesheet ) { $_child->parent = null; $_child->errors = new WP_Error( 'theme_parent_invalid', sprintf( __( 'The "%s" theme is not a valid parent theme.' ), esc_html( $_child->template ) ) ); $_child->cache_add( 'theme', array( 'headers' => $_child->headers, 'errors' => $_child->errors, 'stylesheet' => $_child->stylesheet, 'template' => $_child->template ) ); // The two themes actually reference each other with the Template header. if ( $_child->stylesheet == $this->template ) { $this->errors = new WP_Error( 'theme_parent_invalid', sprintf( __( 'The "%s" theme is not a valid parent theme.' ), esc_html( $this->template ) ) ); $this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ) ); } return; } // Set the parent. Pass the current instance so we can do the crazy checks above and assess errors. $this->parent = new WP_Theme( $this->template, isset( $theme_root_template ) ? $theme_root_template : $this->theme_root, $this ); } // We're good. If we didn't retrieve from cache, set it. if ( ! is_array( $cache ) ) { $cache = array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet, 'template' => $this->template ); // If the parent theme is in another root, we'll want to cache this. Avoids an entire branch of filesystem calls above. if ( isset( $theme_root_template ) ) $cache['theme_root_template'] = $theme_root_template; $this->cache_add( 'theme', $cache ); } } /** * When converting the object to a string, the theme name is returned. * * @return string Theme name, ready for display (translated) */ public function __toString() { return (string) $this->display('Name'); } /** * __isset() magic method for properties formerly returned by current_theme_info() * * @staticvar array $properties * * @return bool */ public function __isset( $offset ) { static $properties = array( 'name', 'title', 'version', 'parent_theme', 'template_dir', 'stylesheet_dir', 'template', 'stylesheet', 'screenshot', 'description', 'author', 'tags', 'theme_root', 'theme_root_uri', ); return in_array( $offset, $properties ); } /** * __get() magic method for properties formerly returned by current_theme_info() * * @return mixed */ public function __get( $offset ) { switch ( $offset ) { case 'name' : case 'title' : return $this->get('Name'); case 'version' : return $this->get('Version'); case 'parent_theme' : return $this->parent() ? $this->parent()->get('Name') : ''; case 'template_dir' : return $this->get_template_directory(); case 'stylesheet_dir' : return $this->get_stylesheet_directory(); case 'template' : return $this->get_template(); case 'stylesheet' : return $this->get_stylesheet(); case 'screenshot' : return $this->get_screenshot( 'relative' ); // 'author' and 'description' did not previously return translated data. case 'description' : return $this->display('Description'); case 'author' : return $this->display('Author'); case 'tags' : return $this->get( 'Tags' ); case 'theme_root' : return $this->get_theme_root(); case 'theme_root_uri' : return $this->get_theme_root_uri(); // For cases where the array was converted to an object. default : return $this->offsetGet( $offset ); } } /** * Method to implement ArrayAccess for keys formerly returned by get_themes() * * @param mixed $offset * @param mixed $value */ public function offsetSet( $offset, $value ) {} /** * Method to implement ArrayAccess for keys formerly returned by get_themes() * * @param mixed $offset */ public function offsetUnset( $offset ) {} /** * Method to implement ArrayAccess for keys formerly returned by get_themes() * * @staticvar array $keys * * @param mixed $offset * @return bool */ public function offsetExists( $offset ) { static $keys = array( 'Name', 'Version', 'Status', 'Title', 'Author', 'Author Name', 'Author URI', 'Description', 'Template', 'Stylesheet', 'Template Files', 'Stylesheet Files', 'Template Dir', 'Stylesheet Dir', 'Screenshot', 'Tags', 'Theme Root', 'Theme Root URI', 'Parent Theme', ); return in_array( $offset, $keys ); } /** * Method to implement ArrayAccess for keys formerly returned by get_themes(). * * Author, Author Name, Author URI, and Description did not previously return * translated data. We are doing so now as it is safe to do. However, as * Name and Title could have been used as the key for get_themes(), both remain * untranslated for back compatibility. This means that ['Name'] is not ideal, * and care should be taken to use $theme->display('Name') to get a properly * translated header. * * @param mixed $offset * @return mixed */ public function offsetGet( $offset ) { switch ( $offset ) { case 'Name' : case 'Title' : // See note above about using translated data. get() is not ideal. // It is only for backwards compatibility. Use display(). return $this->get('Name'); case 'Author' : return $this->display( 'Author'); case 'Author Name' : return $this->display( 'Author', false); case 'Author URI' : return $this->display('AuthorURI'); case 'Description' : return $this->display( 'Description'); case 'Version' : case 'Status' : return $this->get( $offset ); case 'Template' : return $this->get_template(); case 'Stylesheet' : return $this->get_stylesheet(); case 'Template Files' : return $this->get_files( 'php', 1, true ); case 'Stylesheet Files' : return $this->get_files( 'css', 0, false ); case 'Template Dir' : return $this->get_template_directory(); case 'Stylesheet Dir' : return $this->get_stylesheet_directory(); case 'Screenshot' : return $this->get_screenshot( 'relative' ); case 'Tags' : return $this->get('Tags'); case 'Theme Root' : return $this->get_theme_root(); case 'Theme Root URI' : return $this->get_theme_root_uri(); case 'Parent Theme' : return $this->parent() ? $this->parent()->get('Name') : ''; default : return null; } } /** * Returns errors property. * * @since 3.4.0 * @access public * * @return WP_Error|false WP_Error if there are errors, or false. */ public function errors() { return is_wp_error( $this->errors ) ? $this->errors : false; } /** * Whether the theme exists. * * A theme with errors exists. A theme with the error of 'theme_not_found', * meaning that the theme's directory was not found, does not exist. * * @since 3.4.0 * @access public * * @return bool Whether the theme exists. */ public function exists() { return ! ( $this->errors() && in_array( 'theme_not_found', $this->errors()->get_error_codes() ) ); } /** * Returns reference to the parent theme. * * @since 3.4.0 * @access public * * @return WP_Theme|false Parent theme, or false if the current theme is not a child theme. */ public function parent() { return isset( $this->parent ) ? $this->parent : false; } /** * Adds theme data to cache. * * Cache entries keyed by the theme and the type of data. * * @since 3.4.0 * @access private * * @param string $key Type of data to store (theme, screenshot, headers, page_templates) * @param string $data Data to store * @return bool Return value from wp_cache_add() */ private function cache_add( $key, $data ) { return wp_cache_add( $key . '-' . $this->cache_hash, $data, 'themes', self::$cache_expiration ); } /** * Gets theme data from cache. * * Cache entries are keyed by the theme and the type of data. * * @since 3.4.0 * @access private * * @param string $key Type of data to retrieve (theme, screenshot, headers, page_templates) * @return mixed Retrieved data */ private function cache_get( $key ) { return wp_cache_get( $key . '-' . $this->cache_hash, 'themes' ); } /** * Clears the cache for the theme. * * @since 3.4.0 * @access public */ public function cache_delete() { foreach ( array( 'theme', 'screenshot', 'headers', 'page_templates' ) as $key ) wp_cache_delete( $key . '-' . $this->cache_hash, 'themes' ); $this->template = $this->textdomain_loaded = $this->theme_root_uri = $this->parent = $this->errors = $this->headers_sanitized = $this->name_translated = null; $this->headers = array(); $this->__construct( $this->stylesheet, $this->theme_root ); } /** * Get a raw, unformatted theme header. * * The header is sanitized, but is not translated, and is not marked up for display. * To get a theme header for display, use the display() method. * * Use the get_template() method, not the 'Template' header, for finding the template. * The 'Template' header is only good for what was written in the style.css, while * get_template() takes into account where WordPress actually located the theme and * whether it is actually valid. * * @since 3.4.0 * @access public * * @param string $header Theme header. Name, Description, Author, Version, ThemeURI, AuthorURI, Status, Tags. * @return string|false String on success, false on failure. */ public function get( $header ) { if ( ! isset( $this->headers[ $header ] ) ) return false; if ( ! isset( $this->headers_sanitized ) ) { $this->headers_sanitized = $this->cache_get( 'headers' ); if ( ! is_array( $this->headers_sanitized ) ) $this->headers_sanitized = array(); } if ( isset( $this->headers_sanitized[ $header ] ) ) return $this->headers_sanitized[ $header ]; // If themes are a persistent group, sanitize everything and cache it. One cache add is better than many cache sets. if ( self::$persistently_cache ) { foreach ( array_keys( $this->headers ) as $_header ) $this->headers_sanitized[ $_header ] = $this->sanitize_header( $_header, $this->headers[ $_header ] ); $this->cache_add( 'headers', $this->headers_sanitized ); } else { $this->headers_sanitized[ $header ] = $this->sanitize_header( $header, $this->headers[ $header ] ); } return $this->headers_sanitized[ $header ]; } /** * Gets a theme header, formatted and translated for display. * * @since 3.4.0 * @access public * * @param string $header Theme header. Name, Description, Author, Version, ThemeURI, AuthorURI, Status, Tags. * @param bool $markup Optional. Whether to mark up the header. Defaults to true. * @param bool $translate Optional. Whether to translate the header. Defaults to true. * @return string|false Processed header, false on failure. */ public function display( $header, $markup = true, $translate = true ) { $value = $this->get( $header ); if ( false === $value ) { return false; } if ( $translate && ( empty( $value ) || ! $this->load_textdomain() ) ) $translate = false; if ( $translate ) $value = $this->translate_header( $header, $value ); if ( $markup ) $value = $this->markup_header( $header, $value, $translate ); return $value; } /** * Sanitize a theme header. * * @since 3.4.0 * @access private * * @staticvar array $header_tags * @staticvar array $header_tags_with_a * * @param string $header Theme header. Name, Description, Author, Version, ThemeURI, AuthorURI, Status, Tags. * @param string $value Value to sanitize. * @return mixed */ private function sanitize_header( $header, $value ) { switch ( $header ) { case 'Status' : if ( ! $value ) { $value = 'publish'; break; } // Fall through otherwise. case 'Name' : static $header_tags = array( 'abbr' => array( 'title' => true ), 'acronym' => array( 'title' => true ), 'code' => true, 'em' => true, 'strong' => true, ); $value = wp_kses( $value, $header_tags ); break; case 'Author' : // There shouldn't be anchor tags in Author, but some themes like to be challenging. case 'Description' : static $header_tags_with_a = array( 'a' => array( 'href' => true, 'title' => true ), 'abbr' => array( 'title' => true ), 'acronym' => array( 'title' => true ), 'code' => true, 'em' => true, 'strong' => true, ); $value = wp_kses( $value, $header_tags_with_a ); break; case 'ThemeURI' : case 'AuthorURI' : $value = esc_url_raw( $value ); break; case 'Tags' : $value = array_filter( array_map( 'trim', explode( ',', strip_tags( $value ) ) ) ); break; case 'Version' : $value = strip_tags( $value ); break; } return $value; } /** * Mark up a theme header. * * @since 3.4.0 * @access private * * @staticvar string $comma * * @param string $header Theme header. Name, Description, Author, Version, ThemeURI, AuthorURI, Status, Tags. * @param string $value Value to mark up. * @param string $translate Whether the header has been translated. * @return string Value, marked up. */ private function markup_header( $header, $value, $translate ) { switch ( $header ) { case 'Name' : if ( empty( $value ) ) { $value = esc_html( $this->get_stylesheet() ); } break; case 'Description' : $value = wptexturize( $value ); break; case 'Author' : if ( $this->get('AuthorURI') ) { $value = sprintf( '%2$s', $this->display( 'AuthorURI', true, $translate ), $value ); } elseif ( ! $value ) { $value = __( 'Anonymous' ); } break; case 'Tags' : static $comma = null; if ( ! isset( $comma ) ) { /* translators: used between list items, there is a space after the comma */ $comma = __( ', ' ); } $value = implode( $comma, $value ); break; case 'ThemeURI' : case 'AuthorURI' : $value = esc_url( $value ); break; } return $value; } /** * Translate a theme header. * * @since 3.4.0 * @access private * * @staticvar array $tags_list * * @param string $header Theme header. Name, Description, Author, Version, ThemeURI, AuthorURI, Status, Tags. * @param string $value Value to translate. * @return string Translated value. */ private function translate_header( $header, $value ) { switch ( $header ) { case 'Name' : // Cached for sorting reasons. if ( isset( $this->name_translated ) ) return $this->name_translated; $this->name_translated = translate( $value, $this->get('TextDomain' ) ); return $this->name_translated; case 'Tags' : if ( empty( $value ) || ! function_exists( 'get_theme_feature_list' ) ) return $value; static $tags_list; if ( ! isset( $tags_list ) ) { $tags_list = array(); $feature_list = get_theme_feature_list( false ); // No API foreach ( $feature_list as $tags ) $tags_list += $tags; } foreach ( $value as &$tag ) { if ( isset( $tags_list[ $tag ] ) ) { $tag = $tags_list[ $tag ]; } elseif ( isset( self::$tag_map[ $tag ] ) ) { $tag = $tags_list[ self::$tag_map[ $tag ] ]; } } return $value; default : $value = translate( $value, $this->get('TextDomain') ); } return $value; } /** * The directory name of the theme's "stylesheet" files, inside the theme root. * * In the case of a child theme, this is directory name of the child theme. * Otherwise, get_stylesheet() is the same as get_template(). * * @since 3.4.0 * @access public * * @return string Stylesheet */ public function get_stylesheet() { return $this->stylesheet; } /** * The directory name of the theme's "template" files, inside the theme root. * * In the case of a child theme, this is the directory name of the parent theme. * Otherwise, the get_template() is the same as get_stylesheet(). * * @since 3.4.0 * @access public * * @return string Template */ public function get_template() { return $this->template; } /** * Returns the absolute path to the directory of a theme's "stylesheet" files. * * In the case of a child theme, this is the absolute path to the directory * of the child theme's files. * * @since 3.4.0 * @access public * * @return string Absolute path of the stylesheet directory. */ public function get_stylesheet_directory() { if ( $this->errors() && in_array( 'theme_root_missing', $this->errors()->get_error_codes() ) ) return ''; return $this->theme_root . '/' . $this->stylesheet; } /** * Returns the absolute path to the directory of a theme's "template" files. * * In the case of a child theme, this is the absolute path to the directory * of the parent theme's files. * * @since 3.4.0 * @access public * * @return string Absolute path of the template directory. */ public function get_template_directory() { if ( $this->parent() ) $theme_root = $this->parent()->theme_root; else $theme_root = $this->theme_root; return $theme_root . '/' . $this->template; } /** * Returns the URL to the directory of a theme's "stylesheet" files. * * In the case of a child theme, this is the URL to the directory of the * child theme's files. * * @since 3.4.0 * @access public * * @return string URL to the stylesheet directory. */ public function get_stylesheet_directory_uri() { return $this->get_theme_root_uri() . '/' . str_replace( '%2F', '/', rawurlencode( $this->stylesheet ) ); } /** * Returns the URL to the directory of a theme's "template" files. * * In the case of a child theme, this is the URL to the directory of the * parent theme's files. * * @since 3.4.0 * @access public * * @return string URL to the template directory. */ public function get_template_directory_uri() { if ( $this->parent() ) $theme_root_uri = $this->parent()->get_theme_root_uri(); else $theme_root_uri = $this->get_theme_root_uri(); return $theme_root_uri . '/' . str_replace( '%2F', '/', rawurlencode( $this->template ) ); } /** * The absolute path to the directory of the theme root. * * This is typically the absolute path to wp-content/themes. * * @since 3.4.0 * @access public * * @return string Theme root. */ public function get_theme_root() { return $this->theme_root; } /** * Returns the URL to the directory of the theme root. * * This is typically the absolute URL to wp-content/themes. This forms the basis * for all other URLs returned by WP_Theme, so we pass it to the public function * get_theme_root_uri() and allow it to run the theme_root_uri filter. * * @since 3.4.0 * @access public * * @return string Theme root URI. */ public function get_theme_root_uri() { if ( ! isset( $this->theme_root_uri ) ) $this->theme_root_uri = get_theme_root_uri( $this->stylesheet, $this->theme_root ); return $this->theme_root_uri; } /** * Returns the main screenshot file for the theme. * * The main screenshot is called screenshot.png. gif and jpg extensions are also allowed. * * Screenshots for a theme must be in the stylesheet directory. (In the case of child * themes, parent theme screenshots are not inherited.) * * @since 3.4.0 * @access public * * @param string $uri Type of URL to return, either 'relative' or an absolute URI. Defaults to absolute URI. * @return string|false Screenshot file. False if the theme does not have a screenshot. */ public function get_screenshot( $uri = 'uri' ) { $screenshot = $this->cache_get( 'screenshot' ); if ( $screenshot ) { if ( 'relative' == $uri ) return $screenshot; return $this->get_stylesheet_directory_uri() . '/' . $screenshot; } elseif ( 0 === $screenshot ) { return false; } foreach ( array( 'png', 'gif', 'jpg', 'jpeg' ) as $ext ) { if ( file_exists( $this->get_stylesheet_directory() . "/screenshot.$ext" ) ) { $this->cache_add( 'screenshot', 'screenshot.' . $ext ); if ( 'relative' == $uri ) return 'screenshot.' . $ext; return $this->get_stylesheet_directory_uri() . '/' . 'screenshot.' . $ext; } } $this->cache_add( 'screenshot', 0 ); return false; } /** * Return files in the theme's directory. * * @since 3.4.0 * @access public * * @param mixed $type Optional. Array of extensions to return. Defaults to all files (null). * @param int $depth Optional. How deep to search for files. Defaults to a flat scan (0 depth). -1 depth is infinite. * @param bool $search_parent Optional. Whether to return parent files. Defaults to false. * @return array Array of files, keyed by the path to the file relative to the theme's directory, with the values * being absolute paths. */ public function get_files( $type = null, $depth = 0, $search_parent = false ) { $files = (array) self::scandir( $this->get_stylesheet_directory(), $type, $depth ); if ( $search_parent && $this->parent() ) $files += (array) self::scandir( $this->get_template_directory(), $type, $depth ); return $files; } /** * Returns the theme's page templates. * * @since 3.4.0 * @access public * * @param WP_Post|null $post Optional. The post being edited, provided for context. * @return array Array of page templates, keyed by filename, with the value of the translated header name. */ public function get_page_templates( $post = null ) { // If you screw up your current theme and we invalidate your parent, most things still work. Let it slide. if ( $this->errors() && $this->errors()->get_error_codes() !== array( 'theme_parent_invalid' ) ) return array(); $page_templates = $this->cache_get( 'page_templates' ); if ( ! is_array( $page_templates ) ) { $page_templates = array(); $files = (array) $this->get_files( 'php', 1 ); foreach ( $files as $file => $full_path ) { if ( ! preg_match( '|Template Name:(.*)$|mi', file_get_contents( $full_path ), $header ) ) continue; $page_templates[ $file ] = _cleanup_header_comment( $header[1] ); } $this->cache_add( 'page_templates', $page_templates ); } if ( $this->load_textdomain() ) { foreach ( $page_templates as &$page_template ) { $page_template = $this->translate_header( 'Template Name', $page_template ); } } if ( $this->parent() ) $page_templates += $this->parent()->get_page_templates( $post ); /** * Filter list of page templates for a theme. * * This filter does not currently allow for page templates to be added. * * @since 3.9.0 * * @param array $page_templates Array of page templates. Keys are filenames, * values are translated names. * @param WP_Theme $this The theme object. * @param WP_Post|null $post The post being edited, provided for context, or null. */ $return = apply_filters( 'theme_page_templates', $page_templates, $this, $post ); return array_intersect_assoc( $return, $page_templates ); } /** * Scans a directory for files of a certain extension. * * @since 3.4.0 * * @static * @access private * * @param string $path Absolute path to search. * @param array|string|null $extensions Optional. Array of extensions to find, string of a single extension, * or null for all extensions. Default null. * @param int $depth Optional. How many levels deep to search for files. Accepts 0, 1+, or * -1 (infinite depth). Default 0. * @param string $relative_path Optional. The basename of the absolute path. Used to control the * returned path for the found files, particularly when this function * recurses to lower depths. Default empty. * @return array|false Array of files, keyed by the path to the file relative to the `$path` directory prepended * with `$relative_path`, with the values being absolute paths. False otherwise. */ private static function scandir( $path, $extensions = null, $depth = 0, $relative_path = '' ) { if ( ! is_dir( $path ) ) return false; if ( $extensions ) { $extensions = (array) $extensions; $_extensions = implode( '|', $extensions ); } $relative_path = trailingslashit( $relative_path ); if ( '/' == $relative_path ) $relative_path = ''; $results = scandir( $path ); $files = array(); foreach ( $results as $result ) { if ( '.' == $result[0] ) continue; if ( is_dir( $path . '/' . $result ) ) { if ( ! $depth || 'CVS' == $result ) continue; $found = self::scandir( $path . '/' . $result, $extensions, $depth - 1 , $relative_path . $result ); $files = array_merge_recursive( $files, $found ); } elseif ( ! $extensions || preg_match( '~\.(' . $_extensions . ')$~', $result ) ) { $files[ $relative_path . $result ] = $path . '/' . $result; } } return $files; } /** * Loads the theme's textdomain. * * Translation files are not inherited from the parent theme. Todo: if this fails for the * child theme, it should probably try to load the parent theme's translations. * * @since 3.4.0 * @access public * * @return bool True if the textdomain was successfully loaded or has already been loaded. * False if no textdomain was specified in the file headers, or if the domain could not be loaded. */ public function load_textdomain() { if ( isset( $this->textdomain_loaded ) ) return $this->textdomain_loaded; $textdomain = $this->get('TextDomain'); if ( ! $textdomain ) { $this->textdomain_loaded = false; return false; } if ( is_textdomain_loaded( $textdomain ) ) { $this->textdomain_loaded = true; return true; } $path = $this->get_stylesheet_directory(); if ( $domainpath = $this->get('DomainPath') ) $path .= $domainpath; else $path .= '/languages'; $this->textdomain_loaded = load_theme_textdomain( $textdomain, $path ); return $this->textdomain_loaded; } /** * Whether the theme is allowed (multisite only). * * @since 3.4.0 * @access public * * @param string $check Optional. Whether to check only the 'network'-wide settings, the 'site' * settings, or 'both'. Defaults to 'both'. * @param int $blog_id Optional. Ignored if only network-wide settings are checked. Defaults to current blog. * @return bool Whether the theme is allowed for the network. Returns true in single-site. */ public function is_allowed( $check = 'both', $blog_id = null ) { if ( ! is_multisite() ) return true; if ( 'both' == $check || 'network' == $check ) { $allowed = self::get_allowed_on_network(); if ( ! empty( $allowed[ $this->get_stylesheet() ] ) ) return true; } if ( 'both' == $check || 'site' == $check ) { $allowed = self::get_allowed_on_site( $blog_id ); if ( ! empty( $allowed[ $this->get_stylesheet() ] ) ) return true; } return false; } /** * Returns array of stylesheet names of themes allowed on the site or network. * * @since 3.4.0 * * @static * @access public * * @param int $blog_id Optional. Defaults to current blog. * @return array Array of stylesheet names. */ public static function get_allowed( $blog_id = null ) { /** * Filter the array of themes allowed on the site or network. * * @since MU * * @param array $allowed_themes An array of theme stylesheet names. */ $network = (array) apply_filters( 'allowed_themes', self::get_allowed_on_network() ); return $network + self::get_allowed_on_site( $blog_id ); } /** * Returns array of stylesheet names of themes allowed on the network. * * @since 3.4.0 * * @static * @access public * * @staticvar array $allowed_themes * * @return array Array of stylesheet names. */ public static function get_allowed_on_network() { static $allowed_themes; if ( ! isset( $allowed_themes ) ) $allowed_themes = (array) get_site_option( 'allowedthemes' ); return $allowed_themes; } /** * Returns array of stylesheet names of themes allowed on the site. * * @since 3.4.0 * * @static * @access public * * @staticvar array $allowed_themes * * @param int $blog_id Optional. Defaults to current blog. * @return array Array of stylesheet names. */ public static function get_allowed_on_site( $blog_id = null ) { static $allowed_themes = array(); if ( ! $blog_id || ! is_multisite() ) $blog_id = get_current_blog_id(); if ( isset( $allowed_themes[ $blog_id ] ) ) return $allowed_themes[ $blog_id ]; $current = $blog_id == get_current_blog_id(); if ( $current ) { $allowed_themes[ $blog_id ] = get_option( 'allowedthemes' ); } else { switch_to_blog( $blog_id ); $allowed_themes[ $blog_id ] = get_option( 'allowedthemes' ); restore_current_blog(); } // This is all super old MU back compat joy. // 'allowedthemes' keys things by stylesheet. 'allowed_themes' keyed things by name. if ( false === $allowed_themes[ $blog_id ] ) { if ( $current ) { $allowed_themes[ $blog_id ] = get_option( 'allowed_themes' ); } else { switch_to_blog( $blog_id ); $allowed_themes[ $blog_id ] = get_option( 'allowed_themes' ); restore_current_blog(); } if ( ! is_array( $allowed_themes[ $blog_id ] ) || empty( $allowed_themes[ $blog_id ] ) ) { $allowed_themes[ $blog_id ] = array(); } else { $converted = array(); $themes = wp_get_themes(); foreach ( $themes as $stylesheet => $theme_data ) { if ( isset( $allowed_themes[ $blog_id ][ $theme_data->get('Name') ] ) ) $converted[ $stylesheet ] = true; } $allowed_themes[ $blog_id ] = $converted; } // Set the option so we never have to go through this pain again. if ( is_admin() && $allowed_themes[ $blog_id ] ) { if ( $current ) { update_option( 'allowedthemes', $allowed_themes[ $blog_id ] ); delete_option( 'allowed_themes' ); } else { switch_to_blog( $blog_id ); update_option( 'allowedthemes', $allowed_themes[ $blog_id ] ); delete_option( 'allowed_themes' ); restore_current_blog(); } } } return (array) $allowed_themes[ $blog_id ]; } /** * Sort themes by name. * * @since 3.4.0 * * @static * @access public */ public static function sort_by_name( &$themes ) { if ( 0 === strpos( get_locale(), 'en_' ) ) { uasort( $themes, array( 'WP_Theme', '_name_sort' ) ); } else { uasort( $themes, array( 'WP_Theme', '_name_sort_i18n' ) ); } } /** * Callback function for usort() to naturally sort themes by name. * * Accesses the Name header directly from the class for maximum speed. * Would choke on HTML but we don't care enough to slow it down with strip_tags(). * * @since 3.4.0 * * @static * @access private * * @return int */ private static function _name_sort( $a, $b ) { return strnatcasecmp( $a->headers['Name'], $b->headers['Name'] ); } /** * Name sort (with translation). * * @since 3.4.0 * * @static * @access private * * @return int */ private static function _name_sort_i18n( $a, $b ) { // Don't mark up; Do translate. return strnatcasecmp( $a->display( 'Name', false, true ), $b->display( 'Name', false, true ) ); } } JavaScript欲速则不达—正则表达式 》 html5jscss

JavaScript欲速则不达—正则表达式

正则表达式是一个威力巨大的处理字符串的工具,能够高效、神奇得完成对字符串的操作。相比较简单的字符串比较、查找、替换,正则表达式提供了更加强大的处理能力。正则表达式的价值就在于,不用正则来解决问题会让人疯掉,但是用了之后“纠结”的问题已不再是问题了。而且因为正则表达式用的不是一个固化的、具体的字符串来匹配字符串,而是抽象的模式的,所以只要正则写的规则没问题,一般都都能高效的完成任务。

虽然正则表达式看起来确实很像外星文,就像变魔术一样,魔术本身也不神奇,只是的观众不解其中奥妙。学会了其中的规则,我们再去使用,肯定会发出感慨:神奇、复杂、好用。

正则到底强在那里呢?我们举个简单的例子:在一串包含数字以及英文字母的字符串中中找出数字并保存在数组中。代码如下:

  1. 不使用正则:

    遍历字符串,利用字符串charAt()的方法将字符串中的数字检索出来,再push数组中,然后继续检索再push到数组中直到结束。

        var str = '12 javascript 34 html5 33 php 77 css';
        var arr = [];
        var figure = '';
        for(var i=0;i='0' && str.charAt(i)<='9'){
                figure += str.charAt(i);
            }else{
                if(figure){
                arr.push(tmp);
                figure ='';
            }
        }
    }
    console.log(arr)//[ "12" , "34" , "5" , "33" , "77" ]
    
    不使用正则提取数字
  2. 使用正则:

    只需要 var arr = str.match(/\d+/g);这样一句代码。

看了以上的例子对比,是不是也觉得很神奇。那我们赶紧来学习神奇而好用的正则吧。

正则表达式基础

javascript中的正则是Perl5的正则表达式语法的大子集,所以在javascript中创建正则有js风格和petl风格两种。

  1. JS 风格: new RegExp('patten','ig')
  2. perl风格:/patten/ig

JS风格其实就是通过RegExp对象来表示,而perl风格更普遍的叫法是RegExp直接量。这两个语法都是一样的,只是转义字符的写法不同。

正则表达式的结构与数学表达式很类似。

为了方便理解,让我们先来看看大家一个典型的的数学表达式:(x+3)*2+y。一个数学表达式由若干个“项”组成,“项”与“项”之间用加号或减号相连;这里“(x+3)*2”和“y”分别是两个项。每个项又由若干个“因子”组成,因子之间用乘号或除号相连;这里第一个项有两个因子“(x+3)”和“2”,而第二个项只有一个因子“y”。每个因子可以是一个简单的数,一个代数变量,也可以是放在括号里面的另一个表达式,括号中的表达式称为“子表达式”。这里“x+3”就是一个子表达式。

与数学表达式的“因子”相对应,构成正则表达式的部件称为“单位”;“项”则与正则表达式的自表达式相对应。而从逻辑上讲,子表达式之间是串接的关系,一个字符串必须与每个子表达式依次相匹配,才算与这个表达式相匹配。

如上例中斜杠后面的 “ig”是匹配模式,可选的值有3个:'i','g','m'。其含义如下:

  1. 'i':为 ignore case,即 忽略大小写。
  2. 'g':为 global search,即全局搜索。
  3. 'm':为 moltiline search,即多行搜索。

为了更好的学习正则,我们再来学习下正则表达式的一些术语

  1. 匹配(matching)

    一个正则表达式“匹配”一个字符串,其实是指这个正则表达式能在字符串中找到匹配文本。

  2. 元字符(metacharacter)

    只有在字符组外部并且是在未转义之前的情况下,才是一个元字符。

  3. 子表达式(subexpression)

    子表达式指的一般是整个正则表达式中的一部分,通常是括号内的表达式,或者有|分隔的多选分支。子表达式由不可分割的单位组成。

    与多选分支不同的是,量词作用的对象是他们之前紧邻的子表达式。而如果量词之前紧邻的是一个括号保卫的自表达式,则不管其多么复杂都被视为一个单元。

一个完整是由一个个“子表达式”组成的,而“子表达式”则是由各种符号组成,上面我们知道,字符就是由“元字符”和“转义字符”组成,按照功能有如下几种:

转义字符

什么是转义字符?在\后面加字符就可以转义为特殊字符。

例如: \n匹配一个换行符, \\匹配“\”。

预定义特殊字符

  1. \o:Nol字符。
  2. \t:水平制表符。
  3. \v:垂直制表符。
  4. \n:换行符。
  5. \r:回车符。
  6. \b:退格符。 只有出现在字符中才有效,即[](中括号)中

以上就是常用的一些直接量字符。

字符类

  1. [ ]:表示范围,一个字符的集合,匹配该集合中的任意一个字符,例如 [abc]就可以匹配"css"中的c;

    如果上例前面加 ^元字符,形如[^asd],则表示匹配除了asd的其他字符;

    如果觉得匹配的字符太多,而且类型相似,则可以用-元字符表示,那么上例就可以这么写[a-c]这么写,所以上例也可以这么写 [^a-d]/p>

  2. \w和\W:\w表示匹配任何ASCII字符组成的单词,等价于[a-zA-Z0-9];\W表示匹配不是ASCII字符组成的单词等价于[^a-zA-Z0-9]。
  3. \s和\S:\s匹配空白符,等价于[\t\n\x0B\f\r];\S则匹配非空白字符,等价于[^\t\n\x0B\f\r]。
  4. \d和\D:\d匹配数字字符,等价于[0-9];\D匹配数字字符,等价于[^0-9]
  5. .:javascript有点特殊,由于浏览器的解析引擎不同,.的匹配范围也有所不同。
    1. IE8以下:

      .匹配所有除了换行符"/n"换行符之外的任意字符。等同于[^\n\r]

    2. IE9以上以及其他浏览器

      .匹配所有除了换行符"/n"换行符和回车符“\r”之外的任意字符。等同于[^\n\r]

    3. document.write(/./.test("\r") + "
      "); document.write(/./.test("\n") + "
      "); /*IE8以下输出true false;IE9以上及其他浏览器输出 false false*/
      .不同浏览器匹配结果

    所以兼容性,还是不要使用 .,使用其他等价的匹配方法。

学完以上的正在表达式语法,如果我们只能让正则匹配字符一次,如果想多几次,就得重复再写一遍。如果要一个字符匹配500次的话,那岂不是要写500次相同。所以我们接下来我们只需要一些代码,就能处理这些数量关系。

量词

首先我们得了解匹配量词都是匹配优先的,简单说就是匹配量词的结果总是尝试匹配尽可能多的字符,直到匹配上限为止,然后为了让整个表达式匹配成功,就需要“释放”之前优先匹配的字符,所以也被称为贪婪模式。

而既然有贪婪模式,则一定也有非贪婪模式。

对于贪婪模式和非贪婪模式影响的是被量词修饰的子表达式的匹配行为,既在贪婪模式下,在整个表达式匹配成功的前提下,尽可能多的匹配,而非贪婪模式在在整个表达式匹配成功的前提下,尽可能少的匹配。而且允许允许接下来的正则继续匹配。

贪婪模式的量词,也叫简单量词,如下:

  1. {n}:n是一个正整数,表示前一个子表达式匹配n次。例如: /o{2}/匹配两次o,它可以匹配”footer“,但是不能匹配hot中的o。
  2. {n,}:n是一个正整数,表示前一个子表达式至少匹配n次。例如:/o{2,}/,它可以匹配“footer”,也可以匹配“fooooooooooter”。
  3. {n,m}:n、m都是正整数,表示至少匹配n次,至多m次。
  4. ?:等价于{0,1}
  5. +:等价于{1,}
  6. *:等价于{0,}

而在贪婪模式后加上 ?就变成了非贪婪模式。

贪婪模式和非贪婪模式

在上面提到的一个前提条件就是在整个表达式匹配成功,为什么要强调这个前提条件呢,看如下例子:

var pattern = 'aAaAaAb';
console.log(/a+/i.exec(pattern)); //aAaAaA
console.log(/a+?/i.exec(pattern)); //a
console.log(/a+b/i.exec(pattern)); //aAaAaAb
console.log(/a+?b/i.exec(pattern)); //aAaAaAb
贪婪模式与非贪婪模式区别事例

全部是在忽略大小写的模式下:

  1. 第一个匹配结果解释:采用贪婪模式,在匹配第一个“a”时,整个表达式匹配成功了,由于采用了贪婪模式,所以仍然向右匹配,向右再也没有可以成功匹配的子字串,匹配结束,最终匹配结果为“aAaAaA”
  2. 第二个匹配结果解释:采用非贪婪模式,在匹配第一个“a”时,整个表达式匹配成功了,由于采用了贪婪模式,所以结束匹配,最终匹配结果为“a。”
  3. 第三个匹配结果解释:采用贪婪模式,所以a+仍然可以匹配到“aAaAaA”,但是由于后面的 b无法匹配成功,所以为了让整个表达式匹配成功,a+必须让出前面的匹配内容,所以最终匹配结果为“aAaAaAb”。
  4. 第四个匹配结果解释:采用非贪婪模式,所以a+任然可以匹配到“a”,但是由于后面的 b无法匹配成功,所以为了让整个表达式匹配成功,a+必须继续匹配后面的直到“b”,所以最终匹配结果跟采用贪婪模式的匹配结果一样,也为“aAaAaAb”。

所以,不管是贪婪模式还是非贪婪模式,都只有 在整个表达式匹配成功的前提下量词才能影响字表达式的匹配行为

匹配位置

前面说的量词是修饰子字符串的重复次数,而匹配位置则是来表示子字符串的出现位置,匹配的只是一个位置,所以是零宽度的。

  1. ^:匹配文字的开头。如果正则表达式的匹配模式设置为','m'则也匹配每个换行符或者回车符之后的位置。
  2. $:匹配文字的开头。如果正则表达式的匹配模式设置为','m'则也匹配每个换行符或者回车符之前的位置。
  3. /b:匹配单词边界,不匹配任何字符。

    所谓的“单词”,就是位于\w(ASCII单词)和\W(非ASCII单词)之间的边界,或者位于ASCII单词与字符串开始或者结尾的合法位置。所以\/bjava/b\不匹配“javascript is more than java”中的javascript中java而只匹配之后的单词“java”。

    而因为javascript只支持ASCII字符不支持Unicode的,所以在javascript这门语言中\w就可以等价于[a-zA-Z0-9],也因为于此,javascript中\w是不包括中文已经其他Unicode码特殊符号的,如下例子:

    var str = "html5_css3中文_h5$c3&汉字%";
    console.log(str.match(/\w+/g)); //"html5_css3" , "_h5" , "c3"
    console.log(str.match(/.\b./g));//"3中" , "文_" , "5$" , "3&"
    
    \w和\b边界的区别

    第一个例子中\w+匹配了"html5_css3" , "_h5" , "c3"三个字符串,而其他的因为javascript只能匹配ASCII码的字符,所以除了字母、数字、“_“以及”$“的字符就都成单词的边界;而当使用.\b.(除了换行符之外的任意字符,.匹配了那些\w无法识别的Unicode码字符)匹配时,我们又得到"3中" , "文_" , "5&" ,说明这个字符串中有4个分界点5个子字符串,分别在"3中" , "文_" , "5&"之间,而四个子字符串分别是"html5_css3","中文,"_h5","$c3","&汉字%"。

    所以,在处理一些字符串时,如果要使用\b得先确认是否还有ASCII码的字符。

    注意:\b[]中表示退格。

分组

学习完以上的,应该会知道中括号用来限定字符类的范围,大括号则用来指定重复的次数,而小括号除了限制多选项的范围以及将若干字符组合为一个单位让量词能影响这个单元。还有一个用途就是,小括号能”记住“它们匹配成功的文本,在正则表达式的后面引用前面“记住”的匹配文本,通过 \后加以为或者多位数字来实现,也就是“反向引用”。

看实际例子吧:

//1分组+量词
console.log(/(js){2}/.test("jsjs"));//true
//2分组+范围
console.log(/[JL]script/.test("Lscript"));//true
//3反向引用
console.log(/([jJ])s\1/.test("jsJs"));//false
console.log(/([jJ])s\1/.test("jsjs"));//true
小括号的作用

例1和例2将括号内的若干字符组合为一个单位。而例3因为\1引用的是之前匹配成功的字符串,所以例三中\1就只能匹配”js“而不能匹配”Js“。

然后介绍第二个分组的符号|

与小括号不同,小括号内的是一个整体(独立的子表达式),而|分割开的各分支是多选分支,即你可以选择|前面的也可以选择|后面的,如果有多个|隔开则是多选几。如下:

var reg = /(html5|css3|js)!!/;
console.log(reg.test("html5!!"));//true
console.log(reg.test("css3!!"));//true
console.log(reg.test("js!!"));//true
候选实例

非捕获性分组

对带圆括号的子表达式的引用确实强大,但是既然能够反向引用,正则引擎肯定是保存了括号内的一些信息。所以从效率角度来看,如果只是为了分组而不反向引用的话就采取非捕获性分组的方法。要创建一个非捕获性分组,只要在捕获性分组的左括号的后面紧跟一个问号与冒号就行了。

从字面意思来看:非捕获分组能分组,但是不能捕获各个组的信息。如下:

var pattern1 = "JS,HTML5,CSS";
console.log(pattern1.replace(/(\w+),(?:\w+)/, "$2,$1"));//$2,JS,CSS
非捕获性分组

前瞻

前瞻也是属于零宽断言,说白了就是匹配位置的高级变体。前面我们说过的只是单纯的开头、结尾以及单词的边界,而前瞻的匹配则更加随意,如下:

  1. (?=p):要求之后的字符必须与p匹配
  2. (?!p):要求之后的字符必须不与p匹配

如下实例:

var reg1 = /java(?!Scrit)/;
var reg2 = /java(?=Scrit)/;
console.log(reg1.test("javaScrit")); //false
console.log(reg1.test("javaB"));//true
console.log(reg2.test("javaScrit")); //true
console.log(reg2.test("javaB"));//false
前瞻

支持正则的方法

首先我们来看看支持正则的字符串方法和 RegExp 自身对象的方法吧。

支持正则表达式的 String 对象的方法

  1. 字符串搜索

    search()方法用于检索字符串中指定的子字符串,返回匹配的字符的位置(0-~)。

    如果没有找到匹配的字符,则返回-1;将忽略RegExp中的全局模式,只返回第一个匹配的位置。

    var pattern = "hello html5 js css";
    console.log(pattern.search(/Html5/i));//6
    
    正则search实例
  2. 字符串匹配

    match()方法可以返回匹配结果的数组,并且依赖于regexp的全局标志g。如果没有全局标志g,则只匹配一次;如果有,则匹配多次直到结束,最后返回一个存有匹配匹配文本的数组。

    match()即不提供与子表达式匹配的文本的信息,也不声明每个匹配子串的索引位置。如果您需要这些信息,可以使用 RegExp.exec()

    var pattern="2012 years 12 month 20 is the end of the world";
    console.log(pattern.match(/\d+/g));//["2012","12","20"]
    
    正则match实例
  3. 字符串替代

    replace()方法用于替换字符串或者正则表达式匹配的子字符串,并且也依赖于regexp的全局标志g。如果没有全局标志g,则只替换第一个匹配的子字符串;如果有,则替换所有匹配的子字符串。

    replace()的第二个参数可以是字符串,也可以是函数。如果是字符串,则由每个匹配的字符串替换,其中 $ 具有特殊的含义:

    1. $n:其中n表示1-99,表示匹配的子字符串中的第n个,n就是带圆括号的子表达式的位置。
    2. $&:全部匹配的子字符串
    3. $`:匹配子串左侧的文本
    4. $':匹配子串右侧的文本
    var pattern1 = "JS,HTML5,CSS";
    var replace1 = pattern1.replace(/(\w{1,}),(\w+)/, "$2,$1");
    console.log(replace1);//HTML5,JS,CSS
    var replace2 = pattern1.replace(/(\w+),/g,"$1-");
    console.log(replace2);//JS-HTML5-CSS
    
    正则replace实例
  4. 字符串分割

    split()方法用于把一个字符串分割成字符串数组。该方法有两个参数,第一个参数是指定分割的边界;第二个参数是指定返回数组的长度,如果没有则字符串之间的都会被分割。

    若使用 split("") 则会将单词分割成字母

    var pattern = "HTML5 JS CSS";
    var sWord1 = pattern.split(" ");
    var sWord2 = pattern.split("");
    console.log(sWord1);//[ "HTML5" , "JS" , "CSS" ]
    console.log(sWord2);//[ "H" , "T" , "M" , "L" , "5" , " " , "J" , "S" , " " , "C" , "S" , "S"]
    
    正则split实例

RegExp 对象的方法

  1. test

    test()方法用于检索要检测的字符串是否存在,若含有与regExp相匹配的文本,则返回true,否则返回false

  2. exec

    exec()方法用于匹配字串,跟不是全局的match()方法很类似,但是它不仅能检索字符串中指定的值,返回找到的值,还能确定其位置。 比match()强大。如果利用 exec() 的lastIndex属性反复调用同样可以模拟match()全局检索字符串的效果。

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