Magento 1.9 createBlock('catalog/product_list') to show specific only products

Question

Here is my code which show products based on specific category

echo $this->getLayout()->createBlock('catalog/product_list')
                        ->setData('category_id', '25')
                        // ->setAttribute('product_type', $category->getName(), 'text')
                        ->setData('column_count', '4')
                        ->setData('mode', 'grid')
                        ->setData('limit', '4')
                        ->setData('name', 'product_list')
                        ->setTemplate('catalog/product/checkout_list.phtml')
                        ->toHtml();

But what I am trying to implement is, say these are product ids 2,4 and Category Id 25 have products 1,2,3,4. So I would like to show only 2 product, but the above method shows all the 4 products. Any only can help me figure out this?

Answer 1

I advise you to create a custom block and load a product collection filtered by your conditions. You would have control over what is loaded there. The collection retrieval would look something like this:

public function getLimitedProductCollection($categoryId, $limit)
{
    $collection = Mage::getResourceModel('catalog/product_collection')
                 ->addCategoryFilter($categoryId);

    $attributesToSelect = [
        'name',
        'url_key'
    ];
     
    $collection->joinAttribute(
        'small_image', 
        'catalog_product/image', 
        'entity_id', 
        null, 
        'left'
    )->addAttributeToSelect('small_image');

    $collection
        ->addMinimalPrice()
        ->addFinalPrice()
        ->addTaxPercents()
        ->addAttributeToSelect($attributesToSelect)
        ->addUrlRewrite();

    Mage::getSingleton('catalog/product_visibility')
        ->addVisibleInCatalogFilterToCollection($collection);
    $collection->setPageSize($limit);

    return $collection->getItems();
}

As you can see, you can easily manipulate the number of items by specifying the $limit, you can add the $categoryId and also you can change or add attributes in the $attributesToSelect array.

Good Luck!