5 worst Magento practices

I hope this article will help many to save their eCommerce problem and to optimize their code. Magento is a wonderful platform to kick start your e-commerce endeavors. But the worst part is its development flow.

I will introduce you the 5 worst Magento development practices followed by detailed example.

1. Collections – query results limitation

To improve code performance and scalability remember to apply limitation on the collection’s query results — it’s much better to do $collection->getSize() instead of $collection->count() or count($collection) because that ways, all of the items will be loaded from the database and than iterated.

2. SQL queries inside a loop

Bad practice is to load Magento models inside a loop. Running SQL query is very expensive operation and doing it in a loop tends to make it even worse. Instead of doing that we could use data collections to load models and then process it.  To be careful when working with collection to do not exceed memory.  Consider $productIds is array of product data.

Bad:

foreach ($productIds as $productId){
    $product = Mage::getModel('catalog/product')->load($productId);
    $this->Storeproducts($product); 
}

Good:

$collection = Mage:getModel('catalog/product')->addFieldsToFilter('entity_id',array('in' => $productIds); foreach ($collection as $product){
$this->Storeproducts($product); }

3. Models loading
We need to remember that each time of executing load() method, separate query’ll be executed on a database. Also loading multiple models separately, slows down our code. Models should be loaded only once with a single SQL query.

Bad:

$name = Mage::getModel('catalog/product')->load($productId)->getName();
$sku = Mage::getModel('catalog/product')->load($productId)->getSku();

Good:

$product = Mage::getModel('catalog/product')->load($productId);
$name = $product->getName();
$sku = $product->getSku();

We also don’t always need the whole model to be loaded — we can do it only when its necessary. In other cases, load only attributes which are needed.

$productId = Mage::getModel('catalog/product')->getIdBySku($sku);  

4. Counting array

PHP function count() is fast but when used in a loop this changes really severely. Calculating the size of an array on each iteration of a loop, if the array or collection contains a lot of items, will result in much longer execution time. Counting size should be done outside the loop not on each iteration.
Bad:

for ($i = 0; $i < count($array); $i++){
    echo $1;
}

Good:

$size = count($array);
for ($i = 0; $i < $size; $i++){
   echo $1;
}

5. Image Optimization

Product image – 250px / 250px and Thumbnail – 120px / 120px
If you want to serve different images for mobile site, always declare width and height for them. 

Don’t make the dimension larger and make sure that all your product images are of the same dimensions for height and width.