class_uses

(PHP 5 >= 5.4.0, PHP 7, PHP 8)

class_uses Return the traits used by the given class

Description

class_uses(object|string $object_or_class, bool $autoload = true): array|false

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.

Parameters

object_or_class

An object (class instance) or a string (class name).

autoload

Whether to autoload if not already loaded.

Return Values

An array on success, or false when the given class doesn't exist.

Examples

Example #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));

?>

The above example will output something similar to:

Array
(
    [foo] => foo
)
Array
(
    [foo] => foo
)
Array
(
    [trait_of_not_loaded] => trait_of_not_loaded
)

See Also

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User Contributed Notes 6 notes

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35
stealz at op dot pl
12 years ago
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);
}
?>
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8
Jos Macedo
4 years ago
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 $traits;}?>
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17
ulf
12 years ago
A slighly modified version from Stealz that also checks all the "parent" traits used by the traits:<?phppublic static function class_uses_deep($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);    }?>
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4
Daniel Klein
7 years ago
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, $autoload = true), which doesn't generate a warning in either case.
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4
Daniel Klein
7 years ago
I have improved on ulf's improvement of stealz' code. I'm pretty sure the last "foreach" adds nothing, so I've removed it, as well as adding a check for string class names (as opposed to objects) to prevent the warning if the class is not found:<?phpfunction class_uses_deep($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);}
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0
donatj at gmail dot com
4 years ago
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;}?>
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