Loop a RecursiveIteratorIterator from an extended RecursiveIterator with extra arguments
Question
Let's say I have following ArrayObject
:
$array_object = new ArrayObject(array(
array('1', '2', '3', '4'),
array('3', '6', '7', '8'),
array('9', '3', '11', '12'),
));
And I extend RecursiveFilterIterator
to accept only children elements which value is equal to some value passed in an argument:
class myRecursiveFilterIterator extends RecursiveFilterIterator
{
public $value;
public function __construct($it, $value)
{
parent::__construct($it);
$this->value = $value;
}
public function accept()
{
return (parent::hasChildren()) || (parent::current() == $this->value);
}
}
I create an instance of this brand new iterator, to filter values equal than 3:
$recursive_filter_iterator = new myRecursiveFilterIterator(new RecursiveArrayIterator($array_object), 3);
If now I loop the whole myRecursiveFilterIterator
using an RecursiveIteratorIterator
:
foreach (new RecursiveIteratorIterator($recursive_filter_iterator) as $value) {
var_dump($value);
}
I get following warning:
Warning: Missing argument 2 for myRecursiveFilterIterator::__construct() in /my/path/test.php on line myLine Notice: Undefined variable: value in /my/path/test.php on line myOtherLine
So it'is like when looping RecursiveIteratorIterator
is trying to instance myRecursiveFilterIterator
without passing second argument $value
.
This doesn't happen if I extend FilterIterator
without supplying extra arguments.
Solution
I decided to run the script my self and this is what have noticed
you are working with multi array so
parent::current()
can be an array that means that the line below is wrong because$this->value
is an integer.return (parent::hasChildren()) || (parent::current() == $this->value);
$this->current ()
also switches String to Array you can do this to manage both depending on what you want to achieveif (is_array ( $current )) { return ($this->hasChildren ()) || (in_array ( ( string ) $this->value, $this->current () )); } else { //var_dump ( $this->value, $this->current () ); return ($this->hasChildren ()) || ( $this->value == $this->current ()); }
You also need to implement
getChildren
method that is why PHP was complaining about Missing argument 2 formyRecursiveFilterIterator::__construct()
public function getChildren() { return new self ( $this->getInnerIterator ()->getChildren (), $this->value ); }
============================== DISCARD OLD RESPONSE =============================
PHP most have communicated a wrong error message .. your code fine but the error originated when you tried to use foreach with RecursiveIteratorIterator directly
Here is a better approach using RecursiveArrayIterator to encapsulate RecursiveIteratorIterator :
foreach (new RecursiveArrayIterator(new RecursiveIteratorIterator($recursive_filter_iterator)) as $value) {
var_dump($value);
}
:)