Magento 2 Advance Search sort by category

Question

I want to display advanced search products with sort of category position, but I don't know which event I need to invoke for this.

Answer 1

Here is the code to sort products by categories position.

$this->_productCollection->getSelect()
    ->joinLeft(
        ['category' => 'catalog_category_product', 'cp' => 'catalog_category_entity'], 
        'e.entity_id = category.product_id',
        ['category.category_id']
    )
    ->joinLeft(
        ['cp' => 'catalog_category_entity'],
        'category.category_id = cp.entity_id',
        ['cp.position']
    )->group('e.entity_id');

$this->_productCollection->getSelect()->order(
    'cp.position ' . $this->getCurrentDirectionReverse()
);