Catalog New Products List Widget cache hole punching

[renaud-charles_pelletier]

I'm using Magento's Catalog New Products List widget on my homepage (inserted via the CMS editor Content > Pages) and I can't get it to refresh when products changes. I tried setting a cache_lifetime of 1 or 0 through the widget **bleep** and it does not seem to work. I then went and edited the widget itself at Model/Catalog/Block/Product/NewProduct.php to force it to have either a cache_lifetime of 1 or null and it does not refresh either when I add new products or change images / price / name.

I also went and made a plugin to modify the getCacheKeyInfo to see if it would make a difference but it does not.

I'm kinda lost at what to search for now. I don't see where I can make it so the widget's cache is cleared on product changes...

Edit: I went and made sure that cache was indeed disabled for the widget by adding this:

// This is a test.
    protected function getCacheLifetime(){
        error_log("Getting Cache Lifetime");
        return null;
    }

The function is called once when the page is loaded after a cache:flush but then it is never called again until another cache:flush.

[renaud-charles_pelletier · Accepted solution]

Managed to get it working using identities related to each products like so:

/**
     * Return identifiers for produced content
     *
     * @return array
     */
    public function getIdentities()
    {   
        $identities = [];

        foreach ($this->_getProductCollection() as $item) {
            $identities = array_merge($identities, $item->getIdentities());
        }

        return $identities;
        
        //return [\Magento\Catalog\Model\Product::CACHE_TAG];
    }

As glad as I am that it finally works I don't understand why cache_lifetime did not work even though identities weren't set.