如何在PHP OOP中仅使用过滤内容创建对象

Question

I have created a class with constructor in php which filter xml file. But the object created take all xml data. How can I avoid that?

Thank you for your help!

My code:

class  Property {
    public $xmlClass;
    public $elemClass = '';
    public $result_array = [];
    public $data = '';

    public function __construct($xml,$elem) {
        $this->xmlClass=$xml;
        $this->elemClass=$elem;

        foreach($xml->list->movie as $value) {
            $data = $value->$elem;
            $result_array[] = $data;
        }

        print_r($result_array);                   //here everything is ok
    }
}

$result_title = new Property('title');
print_r($result_title);    //here object takes all data, not only filtered

Answer 1

$result_title is an object with a lot of props. Among them there's your initial xml as you assign it to xmlClass property.

To get the desired data you need to store it in a class property, you already declare it ($result_array).

So, a proper code could be:

class  Property {
    public $xmlClass;
    public $elemClass = '';
    public $result_array = [];
    public $data = '';

    public function __construct($xml,$elem) {
        $this->xmlClass=$xml;
        $this->elemClass=$elem;

        foreach($xml->list->movie as $value) {
            $data = $value->$elem;
            // add data to a class property `result_array`
            $this->result_array[] = $data;
        }
    }

    // get value of `result_array` with this method
    public function getResultArray() 
    {
        return $this->result_array;
    }
}

$result_title = new Property('title');
print_r($result_title->getResultArray());