php - 通过引用使用 __get()

Question

使用这样的示例类:

class Test{
    public function &__get($name){
        print_r($name);
    }
}

Test 的一个实例将这样返回输出:

$myTest = new Test;
$myTest->foo['bar']['hello'] = 'world';
//outputs only foo

有没有一种方法可以获得有关正在访问数组的哪个维度的更多信息，向我展示(从前面的示例中)foo 的 bar 元素, 和 bar 的 hello 元素被定位了？

Answer 1

您不能使用当前的实现。为了使其工作，您必须创建一个数组对象(即:一个实现 ArrayAccess 的对象)。像这样的东西:

class SuperArray implements ArrayAccess {
    protected $_data = array();
    protected $_parents = array();

    public function __construct(array $data, array $parents = array()) {
        $this->_parents = $parents;
        foreach ($data as $key => $value) {
            if (is_array($value)) {
                $value = new SuperArray($value, array_merge($this->_parents, array($key)));
            }
            $this[$key] = $value;
        }
    }

    public function offsetGet($offset) {
        if (!empty($this->_parents)) echo "['".implode("']['", $this->_parents)."']";
        echo "['$offset'] is being accessed\n";
        return $this->_data[$offset];
    } 

    public function offsetSet($offset, $value) {
        if ($offset === '') $this->_data[] = $value;
        else $this->_data[$offset] = $value;
    } 

    public function offsetUnset($offset) {
        unset($this->_data[$offset]);
    } 

    public function offsetExists($offset) {
        return isset($this->_data[$offset]);
    } 
}

class Test{
    protected $foo;

    public function __construct() {
        $array['bar']['hello'] = 'world';
        $this->foo = new SuperArray($array); 
    }

    public function __get($name){
        echo $name.' is being accessed.'.PHP_EOL;
        return $this->$name;
    }
}

$test = new Test;
echo $test->foo['bar']['hello'];

应该输出:

foo is being accessed.
['bar'] is being accessed
['bar']['hello'] is being accessed
world