Purpose of metadata.xml

Question

Can somebody explain what is the purpose of metadata.xml in components files? For example /components/com_content/metadata.xml

As it almost has no content and I've never seen this in use.

Answer 1

So the purpose of metadata.xml is storing the data that need to be shared across layouts:

each layout.xml inside of your view tmpl directory extends metadata.xml.

---

So if you need to put some request fields in each layout - you can simply add this fields to metadata.xml and all the layouts will inherit them.

For example file /site/view/examples/metadata.xml can look like this

<?xml version="1.0" encoding="utf-8"?>
<metadata>
    <view>
        <options var="additional_request_var">
            <default name="COM_EXAMPLE" msg="COM_EXAMPLE_DESC"/>
            <option name="COM_EXAMPLE_EXT" msg="COM_EXAMPLE_EXT_DESC" value="additional_request_var_value" />
        </options>
    </view>
</metadata>

More at https://github.com/joomplace/JooYii