I asked this question yesterday Static block on home page in Magento, which answered my question about hooking a cms/block to an existing block (content, in that example).
But now I would like to know how to create my own block.
I have this in my .phtml template:
<?php echo $this->getChildHtml('home_flash') ?>
And this in my cms.xml file
<reference name="home_flash">
<block type="cms/block" name="home-page-flash" before="content">
<action method="setBlockId"><block_id>home-page-flash</block_id></action>
</block>
</reference>
But this is not working.
I have also tried to create my own block type, (by copying the breadcrumbs declaration) in the page.xml file:
<block type="page/html_home_block" name="home_block" as="home_block" template="page/template/home_block.phtml"/>
That file exists but isn't being rendered.
However when I reference the block like this:
<block type="page/html_breadcrumbs" name="home_block" as="home_block" template="page/template/home_block.phtml"/>
It renders my home block template, but the original cms/block is not attached to it.
Hope all the different cases show what is happening and highlight the gap in my knowledge well enough for someone to answer, do I have to "register" my new "home_block" type somewhere?