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class_uses

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

class_uses Return the traits used by the given class

Beschreibung

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.

Parameter-Liste

object_or_class

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

autoload

Whether to autoload if not already loaded.

Rückgabewerte

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

Beispiele

Beispiel #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));

?>

Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

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

Siehe auch

add a note

User Contributed Notes 7 notes

up
35
stealz at op dot pl
11 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);
}
?>
up
9
Jos Macedo
3 years ago
Another alternative to get all parent traits is:

<?php
function getUsedTraits($classInstance) {
$parentClasses = class_parents($classInstance);
$traits = class_uses($classInstance);

foreach (
$parentClasses as $parentClass) {
$traits = array_merge($traits, class_uses($parentClass));
}

return
$traits;
}
?>
up
17
ulf
10 years ago
A slighly modified version from Stealz that also checks all the "parent" traits used by the traits:

<?php
public 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);
}
?>
up
4
Daniel Klein
6 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.
up
4
Daniel Klein
6 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:

<?php
function 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);
}
up
0
donatj at gmail dot com
2 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.

<?php

public 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;
}

?>
up
-46
adam at adamhahn dot com
10 years ago
FYI: It is not explicitly stated, but if you run this function against a class that does not use any traits it will return an empty array.

<?php

class iDontUseTraits {
}

class_uses('iDontUseTraits'); // Returns empty array

?>
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