inserting custom block next to each item in checkout cart

Question

I would like to add a custom block next to each item displayed in the shopping cart, which has access to the properties of the specific product it has access to.

Since, this is a part of a plugin, I need to do so without hardcoding anything into core files, i.e. only through the use of layout.xml/event handlers. Any other way which does not involve modifying Magento files.

For example: adding a button which displays itself next to each item in the shopping cart, and performs an action on the SKU of the particular product it is displayed next to.

I will post a screenshot of what I mean shortly.

Just to be clear I do not want to override the existing block, I want to "add" to it

Answer 1

In your module's layout xml file:

<checkout_cart_index>
    <reference name="checkout.cart">
        <action method="addItemRender"><type>simple</type><block>checkout/cart_item_renderer</block><template>custom/cart/item/default.phtml</template></action>
        <action method="addItemRender"><type>grouped</type><block>checkout/cart_item_renderer_grouped</block><template>custom/cart/item/default.phtml</template></action>
        <action method="addItemRender"><type>configurable</type><block>checkout/cart_item_renderer_configurable</block><template>custom/cart/item/default.phtml</template></action>
    </reference>
</checkout_cart_index>

And then override the magento cart render template by copying checkout/cart/item/default.phtml to custom/cart/item/default.phtml. Now you have access to the product by using $_item->getProduct() in your phtml.