Jelix\Dependencies\Resolver::_checkReverseDependencies PHP Method

    protected function _checkReverseDependencies(Item $item)
    {
        if (isset($this->circularReverseDependencyTracker[$item->getName()])) {
            throw new ItemException('Circular reverse dependency! Cannot process the item ' . $item->getName(), $item, 4);
        }
        $this->circularReverseDependencyTracker[$item->getName()] = true;
        foreach ($this->items as $revdepItemName => $revdepItem) {
            $dependencies = $revdepItem->getDependencies();
            if (!isset($dependencies[$item->getName()])) {
                continue;
            }
            if ($revdepItem->getAction() == self::ACTION_INSTALL || $revdepItem->getAction() == self::ACTION_UPGRADE) {
                throw new ItemException('Item ' . $revdepItemName . ' should be removed because of the removal of one of its dependencies, ' . $item->getName() . ', but it asked to be install/upgrade at the same time', $item, 5, $revdepItem);
            }
            if (isset($this->checkedItems[$revdepItemName])) {
                continue;
            }
            if ($revdepItem->getAction() == self::ACTION_REMOVE) {
                $this->_checkReverseDependencies($revdepItem);
                $this->chain[] = $revdepItem;
            } elseif ($revdepItem->getAction() == self::ACTION_NONE) {
                if ($revdepItem->isInstalled()) {
                    $revdepItem->setAction(self::ACTION_REMOVE);
                    $this->_checkReverseDependencies($revdepItem);
                    $this->chain[] = $revdepItem;
                }
            }
        }
        $this->checkedItems[$item->getName()] = true;
        unset($this->circularReverseDependencyTracker[$item->getName()]);
    }