How does Magento 2 render the backend config tabs?

dmitry_fedyuk · November 14, 2015, 4:54am

The template

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/view/adminhtml/templates/system/config/tabs.phtml#L45


 "collapsible": true,
 "animate": 200}}'>
<div class="admin__page-nav-title title _collapsible" data-role="title">
    <strong><?php /* @escapeNotVerified */ echo $_tab->getLabel() ?></strong>
</div>


<ul class="admin__page-nav-items items" data-role="content">
    <?php $_iterator = 1; ?>
    <?php
    /** @var $_section \Magento\Config\Model\Config\Structure\Element\Section */
    foreach ($_tab->getChildren() as $_section): ?>
        <li class="admin__page-nav-item item
            <?php /* @escapeNotVerified */ echo $_section->getClass() ?>
            <?php if ($block->isSectionActive($_section)): ?> _active<?php endif ?>
            <?php echo $_tab->getChildren()->isLast($_section) ? ' _last' : '' ?>">
            <a href="<?php /* @escapeNotVerified */ echo $block->getSectionUrl($_section) ?>"
               class="admin__page-nav-link item-nav">
               <span><?php /* @escapeNotVerified */ echo $_section->getLabel() ?></span>
            </a>
        </li>
        <?php $_iterator++; ?>

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Model/Config/Structure/Element/AbstractComposite.php#L68-L71


public function getChildren()
{
    return $this->_childrenIterator;
}

The iterator’s data:

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Controller/Adminhtml/System/AbstractConfig.php#L50




/**
 * Check if current section is found and is allowed
 *
 * @param \Magento\Framework\App\RequestInterface $request
 * @return \Magento\Framework\App\ResponseInterface
 */
public function dispatch(\Magento\Framework\App\RequestInterface $request)
{
    if (!$request->getParam('section')) {
        $request->setParam('section', $this->_configStructure->getFirstSection()->getId());
    }
    return parent::dispatch($request);
}


/**
 * Check is allow modify system configuration
 *
 * @return bool
 */
protected function _isAllowed()

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Model/Config/Structure.php#L109


}


/**
 * Retrieve first available section in config structure
 *
 * @return \Magento\Config\Model\Config\Structure\ElementInterface
 */
public function getFirstSection()
{
    $tabs = $this->getTabs();
    $tabs->rewind();
    /** @var $tab \Magento\Config\Model\Config\Structure\Element\Tab */
    $tab = $tabs->current();
    $tab->getChildren()->rewind();
    return $tab->getChildren()->current();
}


/**
 * Find element by path parts
 *
 * @param string[] $pathParts

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Model/Config/Structure/Element/Iterator.php#L130




/**
 * Rewind the \Iterator to the first element
 *
 * @return void Any returned value is ignored.
 */
public function rewind()
{
    reset($this->_elements);
    if (current($this->_elements)) {
        $this->_initFlyweight(current($this->_elements));
        if (!$this->current()->isVisible()) {
            $this->next();
        }
    }
}


/**
 * Check whether element is last in list
 *
 * @param \Magento\Config\Model\Config\Structure\ElementInterface $element

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Model/Config/Structure/Element/Iterator.php#L97


}


/**
 * Initialize current flyweight
 *
 * @param array $element
 * @return void
 */
protected function _initFlyweight(array $element)
{
    $this->_flyweight->setData($element, $this->_scope);
}


/**
 * Return the key of the current element
 *
 * @return void
 */
public function key()
{
    key($this->_elements);

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Model/Config/Structure/Element/AbstractComposite.php#L38-L48


public function setData(array $data, $scope)
{
    parent::setData($data, $scope);
    $children = array_key_exists(
        'children',
        $this->_data
    ) && is_array(
        $this->_data['children']
    ) ? $this->_data['children'] : [];
    $this->_childrenIterator->setElements($children, $scope);
}

The tabs gathering

github.com

magento/magento2/blob/2335247d4ae2dc1e0728ee73022b0a244ccd7f4c/app/code/Magento/Config/Model/Config/Structure.php#L77-L88


public function getTabs()
{
    if (isset($this->_data['sections'])) {
        foreach ($this->_data['sections'] as $sectionId => $section) {
            if (isset($section['tab']) && $section['tab']) {
                $this->_data['tabs'][$section['tab']]['children'][$sectionId] = $section;
            }
        }
        $this->_tabIterator->setElements($this->_data['tabs'], $this->_scopeDefiner->getScope());
    }
    return $this->_tabIterator;
}

dmitry_fedyuk · November 14, 2015, 5:27am

See also: Performance issue: \Magento\Config\Model\Config\Structure::getTabs() does not cache its result and is called multiple times for the same result