How does \Magento\Framework\Data\Form\Element\Fieldset::addField() work?

dmitry_fedyuk · November 17, 2015, 7:19am

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Block/System/Config/Form.php#L350-L369


$formField = $fieldset->addField(
    $elementId,
    $field->getType(),
    [
        'name' => $elementName,
        'label' => $field->getLabel($labelPrefix),
        'comment' => $field->getComment($data),
        'tooltip' => $field->getTooltip(),
        'hint' => $field->getHint(),
        'value' => $data,
        'inherit' => $inherit,
        'class' => $field->getFrontendClass() . $sharedClass . $requiresClass,
        'field_config' => $field->getData(),
        'scope' => $this->getScope(),
        'scope_id' => $this->getScopeId(),
        'scope_label' => $this->getScopeLabel($field),
        'can_use_default_value' => $this->canUseDefaultValue($field->showInDefault()),
        'can_use_website_value' => $this->canUseWebsiteValue($field->showInWebsite())
    ]
);

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/lib/internal/Magento/Framework/Data/Form/Element/Fieldset.php#L211


 *
 * @param string $elementId
 * @param string $type
 * @param array $config
 * @param bool $after
 * @param bool $isAdvanced
 * @return AbstractElement
 */
public function addField($elementId, $type, $config, $after = false, $isAdvanced = false)
{
    $element = parent::addField($elementId, $type, $config, $after);
    if ($renderer = Form::getFieldsetElementRenderer()) {
        $element->setRenderer($renderer);
    }
    $element->setAdvanced($isAdvanced);
    return $element;
}


/**
 * Return elements as html string
 *

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/lib/internal/Magento/Framework/Data/Form/AbstractForm.php#L152-L155


if (isset($this->_types[$type])) {
    $type = $this->_types[$type];
}
$element = $this->_factoryElement->create($type, ['data' => $config]);

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/lib/internal/Magento/Framework/Data/Form/Element/Factory.php#L73-L88


public function create($elementType, array $config = [])
{
    if (in_array($elementType, $this->_standardTypes)) {
        $className = 'Magento\Framework\Data\Form\Element\\' . ucfirst($elementType);
    } else {
        $className = $elementType;
    }


    $element = $this->_objectManager->create($className, $config);
    if (!$element instanceof AbstractElement) {
        throw new \InvalidArgumentException(
            $className . ' doesn\'n extend \Magento\Framework\Data\Form\Element\AbstractElement'
        );
    }
    return $element;
}

As you can see, a form element should be an instance of the \Magento\Framework\Data\Form\Element\AbstractElement class.

For the standard elements you can use a short string name.
Magento 2 standard form field types

You can also define some element names for a particular form:

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/lib/internal/Magento/Framework/Data/Form/AbstractForm.php#L152-L154


if (isset($this->_types[$type])) {
    $type = $this->_types[$type];
}

dmitry_fedyuk · November 17, 2015, 8:01am

See also What means «type» attribute for a backend configuration’s form field?