When working in the admin environment of Magento i had to add a controller action that was called by an Ajax request. The problem however is that all layout data is returned as well when calling

$this->renderLayout();

from the controller. So my next attempt was to try to render the block separately and adding it to the layout.

$this->_initCustomer();
$this->getResponse()->setBody(
            $this->getLayout()->createBlock('block/location')
            ->setCustomerId(Mage::registry('current_customer')->getId())
            ->setData('list', $list)
            ->setUseAjax(true)
            ->toHtml()
);

This kinda worked. But now i had no more control over the template used. Or maybe i missed that part. But i don’t like to specify my Block anyway Magento should pick this up automatically.

Solving this issue is actually quite easy. The only thing we need to do is change the layout structure of the module. We change the name to root. And that’s it!

The name attribute tells Magento it is a root block so no need for the rest of the layout.

The last time i had to rewrite one of the core Magento blocks. And that turned out to be quite easy. My new challenge was to rewrite / overwrite one of the Core admin controllers. In this case the Mage_Adminhtml_CustomerController.

I had no idea where to start so i did some googling beforehand. And came to the conclusion that a lot of people are trying to do this. Because of this there is a long list of solutions to solve this. And in most cases developers just advice to drop the Core class in the local folder and work from there. But that doesn’t really make sense. First of all it code duplication in the worst form. And besides that all cool OO stuff like extending is gone.

And since Magento is such a flexible system. There must be a good clean way to solve this. One thread i found had some good info. And i used it as my starting point. There was one problem with this thread. The XML used seems to be an old form of rewriting in Magento.
I found a (lost it) post by one of the Magento devs that shows a new and more clean way of defining this in XML.

In the last post i already created the [Namespace]_All.xml module config. And we can use it for this as well. So we start by telling Magento we are using our own [Namespace_]_Adminhtml module.

<[namespace]_Adminhtml>
    true
    local
    
        
    

create local/Namespace/Adminhtml/controllers/CustomerController.php

The next thing to do is create the actual controller. And add an include line on top to the original file. Magento does not use autoloading for the controllers in this way.

include_once("Mage/Adminhtml/controllers/CustomerController.php");

class [namespace]_Adminhtml_CustomerController extends Mage_Adminhtml_CustomerController
{
	public function somenewAction()
	{

	}
}

Now the Core CustomerController is replaced by our own namespaced version. But it still retains all functionality of the parent.

The only thing left is to create the config file for this module. And tell it to rewrite to the new [namespace]

Create local/[namespace]/Adminhtml/etc/config.xml

	
        <[namespace]_Adminhtml>
            0.1.0
        <[namespace]_Adminhtml>
    

	
    	
    		
    			
    				
    					<[namespace]_Adminhtml before="Mage_Adminhtml">[namespace]_Adminhtml
    				
    			
    		
    	
    

The config section is placed inside the admin tags. because the controller in question is an admin controller. We basically tell Magento that we will be using our own Adminhtml module instead of the Core one. But it will of course fall back on the Core functionality when methods have not been overwritten.

The last few days i have been toying with Magento. and mainly trying to wrap my head around the file structure. It takes quite some time to find all files. So i will be making notes here to keep track of my own progress :)

Today i wanted to add a tab in the customer section of the admin. I am working on a new module and this should be configurable on a per user basis. There for i needed an extra tab to the customer > Manage customers > [customer x] page.

The first challenge was to figure out where Magento stores the tab menu data. I was hoping this came from a database. But after some searching i couldn’t find any reference. It seems to be hard coded in tab files. The customer tab in question can be found here:

app/code/core/Mage/Adminhtml/Block/Customer/Edit/tabs.php

We could of course edit this class. But that’s not according the Magento way. We need to create a local copy of this class. preferably under my own namespace.

To make this happen we first need to tell Magento we are rewriting core modules. So we start of by creating the following file

app/etc/modules/[namespace]_All.xml

And we add the following lines

    
        
            true
            local
            
                
            
        
    

This will tell Magento we have a Core folder under our own namespace. But it still depends on the Mage_Core classes if they are not available in the namespaced location.

Next we need to setup the [namespace]_Core module. We create the folder structure under our own namspace

app/code/local/[namespace]/Core/etc

And we create a new config file here (config.xml) where we will do the actual class rewriting.

    
        <[namespace]_Core>
            0.1.0
        
    
    
        
        	
        		
        			[namespace]_Adminhtml_Block_Customer_Edit_Tabs
        		
        	
        
    

We use the tag to tell Magento we are rewriting a Block class. And then we setup the actual rewrite.

Mage_Adminhtml_Block_Customer_Edit_Tabs is now rewritten too [namespace]_Adminhtml_Block_Customer_Edit_Tabs

The only thing left now is to create the Block class which is located in

app/code/local/[namespace]/Adminhtml/Block/Customer/Edit/Tabs.php

class [namespace]_Adminhtml_Block_Customer_Edit_Tabs extends Mage_Adminhtml_Block_Customer_Edit_Tabs
{
    protected function _beforeToHtml()
    {
	$this->addTab('modulename', array(
            'label'     => Mage::helper('customer')->__('Modulename'),
            'class'     => 'ajax',
            'url'       => $this->getUrl('*/*/modulename', array('_current' => true)),
        ));

        $this->_updateActiveTab();
        return parent::_beforeToHtml();
    }
}