elgg_extract_class(array $array, $existing=[], $extract_key= 'class')
Extract class names from an array, optionally merging into a preexisting set.
elgg_deprecated_notice($msg, $dep_version, $backtrace_level=1)
Log a notice about deprecated use of a function, view, etc.
elgg_extract($key, $array, $default=null, $strict=true)
Checks for $array[$key] and returns its value if it exists, else returns $default.
if(!isset($vars['id'])) $vars['id']