if($item instanceof \ElggEntity) elseif($item instanceof \ElggRiverItem) elseif($item instanceof \ElggRelationship) elseif(is_callable([ $item, 'getType']))
elgg_extract($key, $array, $default=null, bool $strict=true)
Checks for $array[$key] and returns its value if it exists, else returns $default.
if($item instanceof \ElggEntity) elseif($item instanceof \ElggExtender) $value
$item
Render checkbox selector to select the ID of the item.