使用Symfony2将xml反序列化为对象

Question

I collect some data in xml format through an API and would like to deserialize it in an objects list. I'm using Symfony2 and find out JMSSerializerBundle but I do not really know how to use it.

I know that Sf2 allows to serialize/deserialize object to/from array, but I'm looking for something more specific. For example, for this class :

class Screenshot
{
    /**
     * @var integer $id
     */
    private $id;

    /**
     * @var string $url_screenshot
     */
    private $url_screenshot;


    public function __construct($id, $url_screenshot) {
        $this->id = $id;
        $this->url_screenshot = $url_screenshot;
    }


    /**
     * Get id
     *
     * @return integer 
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set url_screenshot
     *
     * @param string $urlScreenshot
     */
    public function setUrlScreenshot($urlScreenshot)
    {
        $this->url_screenshot = $urlScreenshot;
    }

    /**
     * Get url_screenshot
     *
     * @return string 
     */
    public function getUrlScreenshot()
    {
        return $this->url_screenshot;
    }

    /**
     * Serializes the Screenshot object.
     *
     * @return string
     */
    public function serialize()
    {
        return serialize(array(
            $this->id,
            $this->url_screenshot
        ));
    }

    /**
     * Unserializes the Screenshot object.
     *
     * @param string $serialized
     */
    public function unserialize($serialized)
    {
        list(
            $this->id,
            $this->url_screenshot
        ) = unserialize($serialized);
    }

    public function __toString() {
        return "id: ".$this->id
              ."screenshot: ".$this->url_screenshot;
    }
}

I would like serializing/deserializing to/from this kind of xml :

<?xml version="1.0" encoding="UTF-8" ?>
<screenshots>
   <screenshot>
      <id>1</id>
      <url_screenshot>screenshot_url1</url_screenshot>
   </screenshot>
   <screenshot>
      <id>2</id>
      <url_screenshot>screenshot_url2</url_screenshot>
   </screenshot>
   <screenshot>
      <id>3</id>
      <url_screenshot>screenshot_url3</url_screenshot>
   </screenshot>
</screenshots>

I really want to use something integrated/to integrate in Sf2 (something "smooth") and prefer avoiding any homemade xml parsers.

Answer 1

Due to the nature of XML, the exact thing you want, is not possible. You would always need something to translate object -> xml and xml -> object.

My suggestion to you would be a class that works as collection and takes care of it for you, holding the list of objects as property, which can be created from an xml input and create xml output from existing objects.

An alternativ (if you don't really need to have it as xml anymore) would be to simply serialize the objects and store them that way, or searialize an array (or collection object) if you want them all at once. The plain serialize() and unserialize() functions from PHP will do the trick there. Since it's data only, you don't even need the methods serialize and unserialize in your class.

Update: If it's only take the XML into an object, then simplexml already has you covered: http://www.php.net/manual/en/function.simplexml-load-string.php

The second parameter is class name.

Quote: You may use this optional parameter so that simplexml_load_string() will return an object of the specified class. That class should extend the SimpleXMLElement class.

If only this is your goal, then simplexml does it already.

Update 2: I've read some more into the bundle. It does NOT do what you want. It takes an object and the serializes it into XML/YAML, and then of course reverses that process again from those serialized states. It cannot take some random XML file and turn that into a perfect object for you.