What Block Type for Left Column in Magento Theme?

Question

I'm working on a custom Magento (1.3) theme and am wanting to add a left column.

I've created template/page/html/left.phtml with the html in.

In 2columns-left.phtml, i've added the following:

<?php echo $this->getChildHtml('left'); ?>

In page.xml, i've added the following:

<block type="page/html" name="left" as="left" template="page/html/left.phtml" />

What i'm not quite understanding is what that block type should be - it seems to work if I do page/html, core/template or page/html_header - what is this for and what is the correct value for this case, where I just want to effectively include a phtml file - page/html/left.phtml etc.

Thanks,

Ian

Answer 1

This is a simplified version of what's going on, but will hopefully be enough to get you going.

Special Objects

There are three types of Objects that Magento considers "special". These are Models, Blocks, and Helpers. Rather than use class names for these objects Magento uses URI-like strings called class aliases . So this

page/html

corresponds to the Block class

Mage_Page_Block_Html

Class here is referring to PHP classes, not CSS classes.

Magento Page Rendering

A Layout Object is responsible for creating all the HTML for a Magento page.

A Layout Object is a collection of nested Block Objects.

Most Block Objects are Template Blocks, that is, the Block class inherits from the base Magento template block Mage_Core_Block_Template. Template Blocks are objects responsible for rendering a phtml template file.

So, when you specify a "type" in the XML Layout files, you're telling Magento.

I want to add a block object with the class foo/bar, using the template baz.phtml

In code, that's

<!-- "name" and "as" are used to identify the block in the layout, so that 
PHP code can get a reference to the object. -->
<block type="foo/bar" name="myname" as="myname" template="path/to/baz.phtml" />

If all you want to do is render a template file, you can use

type="core/template"

However, by using a different value, like

type="page/html"

your phtml template file gets access to all the methods in

Mage_Page_Block_Html

Which means you could do something like

File: template.phtml

<a href="<?php echo $this->getBaseUrl();?>"></a>

The core/template class doesn't have a getBaseUrl method, but the page/html class does.

If you're doing custom module development (as opposed to just theming), I usually create a Block Object in my own module that extends one of the base Magento blocks. This allows me to add my own methods to the block as I see fit. If you're only theming, page/html is a decent default.