Form with more than one collection - php

Question

I want to realize a form, which is quite simple. The only thing that makes things complicated is that I 'm using two collections in my form. Displaying two collections in the view works like a charme. The problem is the validation and the associated hydration of the bound entity of the form. If all is validated and no errors occur the form instance tries to hydrate the bound entity and ends up with an exception:
Zend\Hydrator\ArraySerializable::hydrate expects the provided object to implement exchangeArray() or populate()
But first the example code ...
The form classes
namespace Application\Form;
use Zend\Form\Element\Collection;
use Zend\Form\Element\Text;
use Zend\Form\Form;
class MyForm extends Form
{
public function __construct($name = '', $options = [])
{
parent::__construct($name, $options);
$this->setAttribute('method', 'post');
$this->setAttribute('id', 'my-form');
}
public function init()
{
$this->add([
'name' => 'my-text-field',
'type' => Text::class,
'attributes' => [
...
],
'options' => [
...
],
]);
// The first collection
$this->add([
'name' => 'first-collection',
'type' => Collection::class,
'options' => [
'count' => 2,
'should_create_template' => true,
'template_placeholder' => '__index__',
'allow_add' => true,
'allow_remove' => true,
'target_element' => [
'type' => FieldsetOne::class,
],
],
]);
// the second collection
$this->add([
'name' => 'second-collection',
'type' => Collection::class,
'options' => [
'count' => 2,
'should_create_template' => true,
'template_placeholder' => '__index__',
'allow_add' => true,
'allow_remove' => true,
'target_element' => [
'type' => FieldsetTwo::class,
],
],
]);
}
}
The metioned Fieldset classes which are bound to the collections look pretty much the same.
namespace Application\Form;
use Zend\Form\Element\Number;
use Zend\Form\Fieldset;
use Zend\InputFilter\InputFilterProviderInterface;
class FieldsetOne extends Fieldset implements InputFilterProviderInterface
{
public function init()
{
$this->add([
'name' => 'my-number',
'type' => Number::class,
'options' => [
...
],
'attributes' => [
...
],
]);
}
public function getInputFilterSpecification()
{
return [
'my-number' => [
'required' => true,
'filters' => [
[
'name' => StripTags::class,
],
[
'name' => ToInt::class,
],
],
'validators' => [
[
'name' => NotEmpty::class,
],
[
'name' => IsInt::class,
'options' => [
'locale' => 'de_DE',
],
],
],
],
];
}
}
Summed up the form got two collections of number elements. All data which is provided over the form should end up in the following entity.
The input filter class
The form gets filtered and validated by the following input filter. The input filter will be bound to the form via a factory. The factory will be shown later.
class MyFormInputFilter extends InputFilter
{
public function init()
{
$this->add([
'name' => 'my-text-field',
'required' => true,
'filters' => [
[
'name' => StripTags::class,
],
[
'name' => StringTrim::class,
],
],
]);
}
}
The input filter contains only settings for the my-text-field element. The collections will be validated with the implemented InputFilterProviderInterface in the fieldsets set as target elements. The input filter class is created over a factory and notated in the input_filters section in the module.config.php.
The form entity
The entity will be bound as an object to the form in a factory it looks like the following example.
namespace Application\Entity;
class MyFormEntity
{
protected $myTextField;
protected $firstCollection;
protected $secondCollection;
public function getMyTextField()
{
return $this->myTextField;
}
public function setMyTextField($myTextField)
{
$this->myTextField = $myTextField;
return $this;
}
public function getFirstCollection()
{
return $this->firstCollection;
}
public function setFirstCollection(array $firstCollection)
{
$this->firstCollection = $firstCollection;
return $this;
}
public function getSecondCollection()
{
return $this->secondCollection;
}
public function setSecondCollection(array $secondCollection)
{
$this->secondCollection = $secondCollection;
return $this;
}
}
This entity will be bound as object to the form. The form will be hydrated be zend 's own ClassMethods hydrator class. For the collections two hydrator strategies are added to the hydrator. The hydrator strategies for the collections look like this.
namespace Application\Hydrator\Strategy;
class FirstCollectionStrategy extends DefaultStrategy
{
public function hydrate($value)
{
$aEntities = [];
if (is_array($value)) {
foreach ($value as $key => $data) {
$aEntities[] = (new ClassMethods(false))->hydrate($data, new CollectionOneEntity());
}
}
return $aEntities;
}
}
This strategy will hydrate the data from collection one to the corresponding entity.
All wrapped up in a factory
This is the factory which creates the form instance.
class MyFormFactory implements FactoryInterface
{
public function createService(ServiceLocatorInterface $serviceLocator)
{
$parentLocator = $serviceLocator->getServiceLocator();
$filter = $parentLocator->get('InputFilterManager')->get(MyFormInputFilter::class);
$hydrator = (new ClassMethods())
->addStrategy('first-collection', new FirstCollectionStrategy())
->addStrategy('second-collection', new SecondCollectionStrategy());
$object = new MyFormEntity();
$form = (new MyForm())
->setInputFilter($filter)
->setHydrator($hydrator)
->setObject($object);
return $form;
}
}
This factory is mentionend in the form_elements section in the module.config.php file.
The problem
Everything works fine. The input element and also the collections are rendered in the view. If the form is submitted and the $form->isValid() method gets called in the controller all ends up in a BadMethodCallException.
Zend\Hydrator\ArraySerializable::hydrate expects the provided object to implement exchangeArray() or populate()
I have not bound the collection entities to the form in the controller because the hydrator strategies are added to the form hydrator that should hydrate the form entity. This makes sense for me, because zend form can only bind one object. If i call the bind method twice in the controller, the first bound object will be overwritten.
Is it possible to add more than one object with the bind method of the form so two collections can be handled? What could alternatives look like? What I 'm doing wrong?