Layout reference doesn't work

Question

I work with blog extension that has it's own layout file. I need to insert my own block inside blog post.

My problem is that if I try to reference post block in my own xml file it doesn't work and getChildHtml returns nothing.

Here is my xml code that adds my block:

<blog_post_view>
...
<reference name="post">
    <block type="core/text" name="test">
        <action method="setText"><text>Hola!</text></action>
    </block>
</reference>
...
</blog_post_view>

If I add this block directly into extension's layout file:

<blog_post_view>
...
<reference name="content">
...
    <block type="blog/post" name="post" template="blog/post.phtml">
        <block type="core/text" name="test">
            <action method="setText"><text>Hola!</text></action>
        </block>
    </block>
</reference>
...
</blog_post_view>

It works properly, getChildHtml returns text block content.

If I add <remove name="post" /> to my own xml it removes post, so my xml file works and the name is correct.

What else can prevent reference from working?

I'm using Magento CE 1.9.1.

Answer 1

Make sure you module depends on the blog module you are using.
So your app/etc/modules/[Namespace]_[Module].xml must contain this:

<?xml version="1.0"?>
<config>
    <modules>
        <[Namespace]_[Module]>
            <codePool>local</codePool><!-- or community -->
            <active>true</active>
            <depends>
                <[Whatever]_Blog />
            </depends>
        </[Namespace]_[Module]>
    </modules>
</config>

this way, your layout file is loaded after the original one.
It works for remove directives because they are parsed differently.