Best practice to add a layout handle for my custom module?

Question

I think I read somewhere that the best place to add a layout handle for a custom module was through the local.xml file in layouts folder. However, almost all modules that I have seen, never has one used the local.xml. Is it the best practice to use local.xml?

Do you have a link to an article explaining this practice? Also, say I just want to add a lone js/css file to the layout on every page, would local.xml's default handle be the best practice to do it OR what is the best approach for it?

Answer 1

You should declare a layout file in your custom module and then create this file in the layout directory, so in config.xml:

<?xml version="1.0"?>
<config>
    ...
    <frontend>
        ...
        <layout>
            <updates>
                <yourmodule>
                    <file>layoutfilename.xml</file>
                </yourmodule>
            </updates>
        </layout>
    </frontend>
</config>

And then create the layout file layoutfilename.xml and inside this declare your layout handles and blocks etc just like any layout file:

<?xml version="1.0"?>
<layout version="0.1.0">
    <default>
        ...
        <reference name="head">
            ...
            <action method="addItem">
                <type>skin_js</type>
                <name>js/somejsfile.js</name>
            </action>
        </reference>
    </default>
</layout>