How to modify frontend layout using custom module

Frontend
1

I built a custom Magento module and I can extend controllers and models without any issues. However, I’m stuck when trying to modify layout XML files properly.

My goal is to update only the multishipping checkout page layout. Right now I can only replace the whole checkout.xml file, but I want to make specific changes using just a small XML snippet in my custom file.

Here’s my current module configuration:

<frontend>
    <layout>
        <updates>
            <shipping>
                <file>custom.xml</file>
            </shipping>
        </updates>
    </layout>
</frontend>

The custom.xml file is located at app/design/frontend/base/default/layout/

What’s the correct way to update specific layout sections instead of overriding entire XML files?

2

Your module setup looks fine, but there’s an issue with the XML structure in your custom.xml file. You need to target the exact layout handle and use proper XML update actions when modifying specific sections. For multishipping checkout changes, create your custom.xml with handles like multishipping_checkout_overview or multishipping_checkout_addresses. Then use XML actions like <action method="">, <reference name="">, or <remove name=""> to make targeted changes. I ran into the same problems customizing checkout layouts. The trick is finding the right layout handle from the multishipping controller and making sure your XML references the correct block names. You can check which handles are active by turning on layout updates logging in developer mode. This lets you make surgical changes without replacing entire layout files - keeps things upgrade-compatible while getting exactly what you want.

3

hey! are you clearing the layout cache after making changes? sometimes updates won’t show even with correct xml because the cache is still holding old versions. what specific elements are you trying to modify on the multishipping page? that’ll help figure out the best way to target those sections.

4

double-check your layout handle name in custom.xml - it needs to match exactly what the controller loads. try wrapping your changes in <checkout_multishipping_overview> tags instead of generic ones. also make sure your block references actually exist, otherwise the updates just get ignored silently.