.
namespace core\output;
use coding_exception;
/**
* This class solves the problem of how to initialise $OUTPUT.
*
* The problem is caused be two factors
*
*
On the one hand, we cannot be sure when output will start. In particular,
* an error, which needs to be displayed, could be thrown at any time.
*
On the other hand, we cannot be sure when we will have all the information
* necessary to correctly initialise $OUTPUT. $OUTPUT depends on the theme, which
* (potentially) depends on the current course, course categories, and logged in user.
* It also depends on whether the current page requires HTTPS.
*
*
* So, it is hard to find a single natural place during Moodle script execution,
* which we can guarantee is the right time to initialise $OUTPUT. Instead we
* adopt the following strategy
*
*
We will initialise $OUTPUT the first time it is used.
*
If, after $OUTPUT has been initialised, the script tries to change something
* that $OUTPUT depends on, we throw an exception making it clear that the script
* did something wrong.
*
*
* The only problem with that is, how do we initialise $OUTPUT on first use if,
* it is going to be used like $OUTPUT->somthing(...)? Well that is where this
* class comes in. Initially, we set up $OUTPUT = new bootstrap_renderer(). Then,
* when any method is called on that object, we initialise $OUTPUT, and pass the call on.
*
* Note that this class is used before lib/outputlib.php has been loaded, so we
* must be careful referring to classes/functions from there, they may not be
* defined yet, and we must avoid fatal errors.
*
* @package core
* @copyright 2009 Tim Hunt
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 2.0
*/
class bootstrap_renderer {
/**
* Handles re-entrancy. Without this, errors or debugging output that occur
* during the initialisation of $OUTPUT, cause infinite recursion.
*
* @var bool
*/
protected $initialising = false;
/**
* Whether output has started yet.
*
* @return bool true if the header has been printed.
*/
public function has_started() {
return false;
}
/**
* Constructor - to be used by core code only.
*
* @param string $method The method to call
* @param array $arguments Arguments to pass to the method being called
* @return string
*/
public function __call($method, $arguments) {
// phpcs:disable moodle.PHP.ForbiddenGlobalUse.BadGlobal
global $OUTPUT, $PAGE;
$recursing = false;
if ($method == 'notification') {
// Catch infinite recursion caused by debugging output during print_header.
// phpcs:ignore PHPCompatibility.FunctionUse.ArgumentFunctionsReportCurrentValue.NeedsInspection
$backtrace = debug_backtrace();
array_shift($backtrace);
array_shift($backtrace);
$recursing = is_early_init($backtrace);
}
$earlymethods = [
'fatal_error' => 'early_error',
'notification' => 'early_notification',
];
// If lib/outputlib.php has been loaded, call it.
if (!empty($PAGE) && !$recursing) {
if (array_key_exists($method, $earlymethods)) {
// Prevent PAGE->context warnings - exceptions might appear before we set any context.
$PAGE->set_context(null);
}
$PAGE->initialise_theme_and_output();
return call_user_func_array([$OUTPUT, $method], $arguments);
}
$this->initialising = true;
// Too soon to initialise $OUTPUT, provide a couple of key methods.
if (array_key_exists($method, $earlymethods)) {
return call_user_func_array([self::class, $earlymethods[$method]], $arguments);
}
throw new coding_exception('Attempt to start output before enough information is known to initialise the theme.');
}
/**
* Returns nicely formatted error message in a div box.
*
* @param string $message error message
* @param ?string $moreinfourl (ignored in early errors)
* @param ?string $link (ignored in early errors)
* @param ?array $backtrace
* @param ?string $debuginfo
* @return string
*/
public static function early_error_content($message, $moreinfourl, $link, $backtrace, $debuginfo = null) {
global $CFG;
$content = "
$message
";
// Check whether debug is set.
$debug = (!empty($CFG->debug) && $CFG->debug >= DEBUG_DEVELOPER);
// Also check we have it set in the config file. This occurs if the method to read the config table from the
// database fails, reading from the config table is the first database interaction we have.
$debug = $debug || (!empty($CFG->config_php_settings['debug']) && $CFG->config_php_settings['debug'] >= DEBUG_DEVELOPER );
if ($debug) {
if (!empty($debuginfo)) {
// Remove all nasty JS.
if (function_exists('s')) { // Function may be not available for some early errors.
$debuginfo = s($debuginfo);
} else {
// Because weblib is not available for these early errors, we
// just duplicate s() code here to be safe.
$debuginfo = preg_replace(
'/&#(\d+|x[0-9a-f]+);/i',
'&#$1;',
htmlspecialchars($debuginfo, ENT_QUOTES | ENT_HTML401 | ENT_SUBSTITUTE)
);
}
$debuginfo = str_replace("\n", ' ', $debuginfo); // Keep newlines.
$content .= '
';
return self::plain_page(get_string('redirect'), $message);
}
/**
* Early redirection page, used before full init of $PAGE global.
*
* @param string $encodedurl redirect url
* @param string $message redirect message
* @param int $delay time in seconds
* @return string redirect page
*/
public static function early_redirect_message($encodedurl, $message, $delay) {
$meta = '';
$content = self::early_error_content($message, null, null, null);
$content .= self::plain_redirect_message($encodedurl);
return self::plain_page(get_string('redirect'), $content, $meta);
}
/**
* Output basic html page.
*
* @param string $title page title
* @param string $content page content
* @param string $meta meta tag
* @return string html page
*/
public static function plain_page($title, $content, $meta = '') {
global $CFG;
if (function_exists('get_string') && function_exists('get_html_lang')) {
$htmllang = get_html_lang();
} else {
$htmllang = '';
}
$footer = '';
if (function_exists('get_performance_info')) { // Function may be not available for some early errors.
if (MDL_PERF_TEST) {
$perfinfo = get_performance_info();
$footer = '';
}
}
ob_start();
include($CFG->dirroot . '/error/plainpage.php');
$html = ob_get_contents();
ob_end_clean();
return $html;
}
}
// Alias this class to the old name.
// This file will be autoloaded by the legacyclasses autoload system.
// In future all uses of this class will be corrected and the legacy references will be removed.
class_alias(bootstrap_renderer::class, \bootstrap_renderer::class);