(PHP 5 >= 5.4.0, PHP 7, PHP 8)
class_uses — Return the traits used by the given class
This function returns an array with the names of the traits that the
given object_or_class uses. This does however not include
any traits used by a parent class.
object_or_classAn object (class instance) or a string (class name).
autoloadWhether to autoload if not already loaded.
An array on success, or false when the given class doesn't exist.
示例 #1 class_uses() example
<?php
trait foo { }
class bar {
use foo;
}
print_r(class_uses(new bar));
print_r(class_uses('bar'));
spl_autoload_register();
// use autoloading to load the 'not_loaded' class
print_r(class_uses('not_loaded', true));
?>以上示例的输出类似于：
Array
(
[foo] => foo
)
Array
(
[foo] => foo
)
Array
(
[trait_of_not_loaded] => trait_of_not_loaded
)
To get ALL traits including those used by parent classes and other traits, use this function:
<?php
function class_uses_deep($class, $autoload = true) {
$traits = [];
do {
$traits = array_merge(class_uses($class, $autoload), $traits);
} while($class = get_parent_class($class));
foreach ($traits as $trait => $same) {
$traits = array_merge(class_uses($trait, $autoload), $traits);
}
return array_unique($traits);
}
?>Another alternative to get all parent traits is:<?phpfunction getUsedTraits($classInstance) { $parentClasses = class_parents($classInstance); $traits = class_uses($classInstance); foreach ($parentClasses as $parentClass) { $traits = array_merge($traits, class_uses($parentClass)); } return $traits;}?>A slighly modified version from Stealz that also checks all the "parent" traits used by the traits:<?phppublic static function class_uses_deep($class, $autoload = true) { $traits = []; // Get traits of all parent classes do { $traits = array_merge(class_uses($class, $autoload), $traits); } while ($class = get_parent_class($class)); // Get traits of all parent traits $traitsToSearch = $traits; while (!empty($traitsToSearch)) { $newTraits = class_uses(array_pop($traitsToSearch), $autoload); $traits = array_merge($newTraits, $traits); $traitsToSearch = array_merge($newTraits, $traitsToSearch); }; foreach ($traits as $trait => $same) { $traits = array_merge(class_uses($trait, $autoload), $traits); } return array_unique($traits); }?>If the class does not exist, you will get a warning, even if $autoload == false; I.e., if the class is not found, setting $autoload to false is not sufficient to silence the warning.This is different from class_exists ($class_name, $autoload = true), which doesn't generate a warning in either case.I have improved on ulf's improvement of stealz' code. I'm pretty sure the last "foreach" adds nothing, so I've removed it, as well as adding a check for string class names (as opposed to objects) to prevent the warning if the class is not found:<?phpfunction class_uses_deep($class, $autoload = true) { $traits = []; // Get all the traits of $class and its parent classes do { $class_name = is_object($class)? get_class($class): $class; if (class_exists($class_name, $autoload)) { $traits = array_merge(class_uses($class, $autoload), $traits); } } while ($class = get_parent_class($class)); // Get traits of all parent traits $traits_to_search = $traits; while (!empty($traits_to_search)) { $new_traits = class_uses(array_pop($traits_to_search), $autoload); $traits = array_merge($new_traits, $traits); $traits_to_search = array_merge($new_traits, $traits_to_search); }; return array_unique($traits);}The popular stealz solution doesn't handle traits that use other traits. A little bit of recursion can clean the entire thing up a bit and make it more robust.<?phppublic function class_uses_deep( string $class, bool $autoload = true ) : array { $traits = class_uses($class, $autoload); if($parent = get_parent_class($class)) { $traits = array_merge($traits, class_uses_deep($parent, $autoload)); } foreach( $traits as $trait ) { $traits = array_merge($traits, class_uses_deep($trait, $autoload)); } return $traits;}?>