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    class_uses

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

    class_uses — 指定したクラスが使っているトレイトを返す

    説明

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

    この関数は、指定した object_or_class が使っているトレイトの名前を配列で返します。 しかし、親クラスで使っているトレイトは含まれません。

    パラメータ

    object_or_class

    オブジェクト (クラスのインスタンス) あるいは文字列 (クラス名)。

    autoload

    まだロードされていない場合に オートロード するかどうか。

    戻り値

    成功した場合に配列、 指定されたクラスが存在しない場合に false を返します。

    例

    例1 class_uses() の例

    <?php

    trait foo { }
    class     bar {
    use     foo;
    }

    print_r(class_uses(new bar));

    print_r(class_uses('bar'));

    spl_autoload_register();

    // オートローディングを使い、'not_loaded' クラスを読み込みます
    print_r(class_uses('not_loaded', true));

    ?>

    上の例の出力は、 たとえば以下のようになります。

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

    参考

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    User Contributed Notes 7 notes

    up
    33
    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);
    }
    ?>
    up
    9
    Jos Macedo
    4 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
    2
    donatj at gmail dot com
    3 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
    14
    ulf
    11 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
    3
    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
    2
    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
    -43
    adam at adamhahn dot com
    11 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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