«Argument 1 passed to Magento\Catalog\Block\Adminhtml\Product\Edit\Tab\ChildTab::setTab() must implement interface Magento\Backend\Block\Widget\Tab\TabInterface, instance of Magento\Framework\DataObject given» while opening a simple product in admin

dmitrii_fediuk · October 4, 2015, 3:44am

The bug is related to Admin Product Page is broken: «Element with ID ‘catalog.product.edit.tab.downloadable.links’ already exists»

See the code:

github.com

magento/magento2/blob/12955b1c7e43c560dc1060c136858531d403c682/app/code/Magento/Catalog/Block/Adminhtml/Product/Edit/Tabs.php#L177


        $tabData = [
            'label' => __($group->getAttributeGroupName()),
            'content' => $this->_translateHtml(
                $tabAttributesBlock->setGroup($group)->setGroupAttributes($attributes)->toHtml()
            ),
            'class' => 'user-defined',
            'group_code' => $group->getTabGroupCode() ?: self::BASIC_TAB_GROUP_CODE,
        ];


        if ($tabData['group_code'] === self::BASIC_TAB_GROUP_CODE) {
            $this->addTab($group->getAttributeGroupCode(), $tabData);
        } else {
            $advancedGroups[$group->getAttributeGroupCode()] = $tabData;
        }
    }
}


/* Don't display website tab for single mode */
if (!$this->_storeManager->isSingleStoreMode()) {
    $this->addTab(
        'websites',

$group->getAttributeGroupCode() can return null.

I opened the eav_attribute_group table and saw that some records has null in attribute_group_code column:

SELECT * FROM  `eav_attribute_group` WHERE attribute_set_id IN (
	SELECT attribute_set_id FROM eav_attribute_set WHERE entity_type_id =4
)

This is because of the incorrect attribute group identifier generation algorithm:
Attribute group code generation algorithm is incorrect because it can return null for an attribute group with non-Latin name

github.com

magento/magento2/blob/12955b1c7e43c560dc1060c136858531d403c682/app/code/Magento/Backend/Block/Widget/Tabs.php#L112




/**
 * Add new tab
 *
 * @param   string $tabId
 * @param   array|\Magento\Framework\DataObject|string $tab
 * @return  $this
 * @throws  \Exception
 * @SuppressWarnings(PHPMD.CyclomaticComplexity)
 */
public function addTab($tabId, $tab)
{
    if (is_array($tab)) {
        $this->_tabs[$tabId] = new \Magento\Framework\DataObject($tab);
    } elseif ($tab instanceof \Magento\Framework\DataObject) {
        $this->_tabs[$tabId] = $tab;
        if (!$this->_tabs[$tabId]->hasTabId()) {
            $this->_tabs[$tabId]->setTabId($tabId);
        }
    } elseif (is_string($tab)) {
        $this->_addTabByName($tab, $tabId);

$group->getAttributeGroupCode() becomes the tab identifier. So we have a tab with null identifier.

github.com

magento/magento2/blob/12955b1c7e43c560dc1060c136858531d403c682/app/code/Magento/Catalog/Block/Adminhtml/Product/Edit/Tabs.php#L347-L349


if ($childTab->getParentTab() === $parentTab->getId()) {
    $html .= $this->getChildBlock('child-tab')->setTab($childTab)->toHtml();
}

$childTab->getParentTab() === $parentTab->getId() compares null with null and returns true.