product attribute to quote item and order item

Question

What is the correct way in Magento to have a product attribute be automatically persisted to quote an item and then finally to order item?

Is it as simple as a little config XML or is it a manual process looking at before saving events and so forth?

Answer 1

one way would be to use an observer and a converter.

the observer would be to get the attribute from the product to the quote (using an attribute called 'test'), and the converter gets the attribute from the quote to the order.

in your config:

<global>
    <fieldsets>
        <sales_convert_quote_item>
            <test>
                <to_order_item>*</to_order_item>
            </test>
        </sales_convert_quote_item>
    </fieldsets>

    <sales>
        <quote>
            <item>
                <product_attributes>
                    <test />
                </product_attributes>
            </item>
        </quote>
    </sales>

    <events>
        <sales_quote_item_set_product>
            <observers>
                <YOUR_MODULE>
                    <class>YOUR_MODULE/observer</class>
                    <method>setTestAttribute</method>
                </YOUR_MODULE>
            </observers>
        </sales_quote_item_set_product>
    </events>
</global>

in your observer:

public function setTestAttribute(Varien_Event_Observer $observer) {

    $item = $observer->getQuoteItem();
    $product = $observer->getProduct();
    $item->setTest($product->getTest());
    return $this;
}

Answer 2

This is done by combining your knowledge of observers and config.xml. Config.xml will manage the provision of a custom attribute definition on the quote item, and an observer will handle saving the product attribute to the quote when added to a quote.

From there, you use config.xml to call the fieldset definition, which will handle the conversion from quote_item to order_item.

Full disclosure: The below content is from Atwix. Link below the answer.

At first, you should add custom attribute to sales->quote->item->product_attributes node:

<sales>
    <quote>
        <item>
            <product_attributes>
                <custom_attribute />
            </product_attributes>
        </item>
    </quote>
</sales>

This makes attribute accessible when we will be copying it from the product to quote item – which is our next step. For this task the observer is used, and the event will be called sales_quote_item_set_product:

<sales_quote_item_set_product>
    <observers>
        <yourmodule_customattribute>
            <class>yourmodule_customattribute/observer</class>
            <method>salesQuoteItemSetCustomAttribute</method>
        </yourmodule_customattribute>
    </observers>
</sales_quote_item_set_product>

Observer:

public function salesQuoteItemSetCustomAttribute($observer)
{
    $quoteItem = $observer->getQuoteItem();
    $product = $observer->getProduct();
    $quoteItem->setCustomAttribute($product->getCustomAttribute());
}

The last thing we need to care about – it is converting attribute from quote_item to order_item. And this can be done with XML:

<fieldsets>
    <sales_convert_quote_item>
        <custom_attribute>
            <to_order_item>*</to_order_item>
        </custom_attribute>
    </sales_convert_quote_item>
    <sales_convert_order_item>
        <custom_attribute>
            <to_quote_item>*</to_quote_item>
        </custom_attribute>
    </sales_convert_order_item>
</fieldsets>

_{Source: Atwix (who is full of win): http://www.atwix.com/magento/custom-product-attribute-quote-order-item/}