如何从ZF2中的现有元素实例中提取工厂友好的表单元素配置数组？

Question

I have a Zend\Form\Element instance and I need to extract all configuration as array from this instance, serialize & persist somewhere and re-use later in a form element factory to generate a similar instance again.

Is there any programatic way exists to get full configuration signature from an already instantiated form element object in zend framework 2?

Answer 1

The short answer is no; you will have to roll your own.

You could create a independent class that can take any element and return the correct array by reading it's public methods; this is effectively reversing the functionality of the FormFactory.

A very brief example

class FormElementSerializer
{
    public function toArray(ElementInterface $element)
    {
        $spec = $this->getElementSpec($element);

        if ($element instanceof FieldsetInterface) {
            $spec = $this->getFieldsetSpec($element, $spec);
        }

        if ($element instanceof Form) {
            $spec = $this->getFormSpec($element, $spec);
        }

        return $spec;
    }

    protected function getElementSpec(ElementInterface $element)
    {
        $spec = array(
            'type' => $this->getElementType($element),
            'name' => $element->getName(),
            'options' => $element->getOptions(),
            'attributes' => $element->getAttributes(),
        );
        return $spec;
    }

    protected function getFieldsetSpec(FieldsetInterface $fieldset, array $spec)
    {
        foreach($fieldset->getElements() as $element) {
            $spec['elements'][] = $this->getElementSpec($element);
        }
        return $spec;
    }

    // deals with hydrators, fieldsets etc
    protected function getFormSpec(FormInterface $form, array $spec);

    // could be as simple as returning the class name
    protected function getElementType(ElementInterface $element);
}