用树枝无法访问对象（stdClass）

Question

I have this object query out from mongodb

object(stdClass)#22 (9) {
  ["_id"]=>
  object(MongoDB\BSON\ObjectID)#19 (1) {
    ["oid"]=>
    string(24) "56639b2aa18994f5398b4567"
  }
  ["Title"]=>
  string(76) "Example movie ..."
  ["ID"]=>
  string(10) "abc12345"
  ["Code"]=>
  string(8) "123456"
  ["Released"]=>
  string(10) "2015-11-27"
  ["Length"]=>
  string(10) "300 min(s)"
  ["Poster"]=>
  string(64) "http://example.net/84orea005pl.jpg"
  ["Episodes"]=>
  object(stdClass)#21 (1) {
    [1]=>
    object(stdClass)#20 (1) {
      ["URL"]=>
      string(38) "http://example.net/movie.e1.m3u8"
    }
  }
  ["View"]=>
  int(31)
}

render by twig

twig->render('movie.html',array('movie' => $movie));

I can access to Title, ID ... easily by doing {{ movie.Title }}, {{ movie.ID }} ... However when I use for loop to loop through movie.Episodes I can't seem to get anything out of it.

{{ dump(movie.Episodes) }}

return

object(stdClass)#21 (1) {
  [1]=>
  object(stdClass)#20 (1) {
    ["URL"]=>
    string(38) "http://example.net/movie.e1.m3u8"
  }
}

but

{% for episode in movie.Episodes %}
testing
{{ dump(episode) }}
{% endfor %}

return empty and it doesn't even loop. So, my question is how can I get the movie episode URL out using twig?

Answer 1

Looks like Twig doesn't know how to handle StdClass, especially when nested. I've had trouble with nested StdClass's before (using SoapClient). I used the following function to convert the nested StdClass's to nested arrays, which are easier to handle and which Twig will understand ...

function objectToArray($data) {
    if (is_object($data))
        $data = get_object_vars($data);
    if (is_array($data))
        return array_map(__FUNCTION__, $data);
    return $data;
}

You'll need to call this on your data (StdClass) before passing it to and invoking Twig.

(Note this function calls itself recursively in the array_map in order to get all the nested StdClass's)

Answer 2

Whereas each object in PHP is "iterable", not all of them are "traversable" using for loop (see http://php.net/manual/en/class.traversable.php ).

An array is by definition traversable but not a stdClass object.

var_dump(new stdClass() instanceof Traversable);

will produce:

bool(false)

I could only suggest you to pass to TWIG a transformed $movie var where its Episodes key is an array and not an stdClass . This could be done with a function like the one above proposed by @BareNakedCoder

Or if you want to manipulate better your object for further features, it could be preferable to construct a new Movie class with this stdClass movie object passed in parameter in __construct()

class Movie
{
    public $id;
    public $oid;
    public $code;
    public $title;
    public $released;
    public $length;
    public $poster;
    public $views;

    /** @var Episode[] $episodes  */
    protected $episodes = [];

    function __construct(stdClass $object = null)
    {
        if (!is_null($object)) {
            $this->oid = $object->_id->oid;

            $this->id = $object->ID;
            $this->code = $object->Code;
            $this->title = $object->Title;
            $this->released = $object->Released;
            $this->length = $object->Length;
            $this->poster = $object->Poster;
            $this->views = $object->View;

            foreach(get_object_vars($object->Episodes) as $ep)
                $this->episodes[] = new Episode($ep);
        }
    }

    public function getEpisodes()
    {
        return $this->episodes;
    }
}

class Episode
{
    public $url;

    function __construct(stdClass $object = null)
    {
        if (!is_null($object))
            $this->url = $object->URL;
    }
}

Your render line will be:

twig->render('movie.html', ['movie' => new Movie($movie)]);

and here is the object you will have in your TWIG context:

object(Movie)#5 (9) {
    ["id"]=>
    string(8) "abc12345"
    ["oid"]=>
    string(24) "56639b2aa18994f5398b4567"
    ["code"]=>
    string(6) "123456"
    ["title"]=>
    string(17) "Example movie ..."
    ["released"]=>
    string(10) "2015-11-27"
    ["length"]=>
    string(10) "300 min(s)"
    ["poster"]=>
    string(34) "http://example.net/84orea005pl.jpg"
    ["views"]=>
    int(31)
    ["episodes":protected]=>
    array(1) {
        [0]=>
        object(Episode)#6 (1) {
            ["url"]=>
            string(32) "http://example.net/movie.e1.m3u8"
        }
    }
}

and no problem to loop the episodes

{% for episode in movie.getEpisodes() %}
  <br>{{ episode.url }}
{% endfor %}

These new Movie / Episode classes are quite simple in this example but you could now add new functions to manipulate your data and theses methods will also be callable from you TWIG templates.

Answer 3

Before pass the data into the twig, try the following:

$data_to_twig = json_encode($your_data);

$data_to_twig = json decode($data_to_twig, true); // the parameter "true" will convert all child objects including stdClass objects to array