master/404_8php_source.html

 <?php
 $error = elgg_extract('error', $vars, elgg_echo('error:404:content'));
 echo elgg_view_message('error', $error);
$error
$error
Page not found error.
Definition: 404.php:6

elgg_echo
elgg_echo(string $message_key, array $args=[], string $language= '')
Elgg language module Functions to manage language and translations.
Definition: languages.php:17

elgg_extract
elgg_extract($key, $array, $default=null, bool $strict=true)
Checks for $array[$key] and returns its value if it exists, else returns $default.
Definition: elgglib.php:254

$vars
$vars
Definition: theme.php:5

elgg_view_message
elgg_view_message(string $type, string $body, array $vars=[])
Wrapper function for the message display pattern.
Definition: views.php:940