WP_REST_URL_Details_Controller::get_icon() WordPress Method

	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;
	}