Fix AJAX Call Not Updating Page in Magento

Some troubleshooting tips:

Do you have a module registered in app/etc/modules?

If not, it should be as such:

<?xml version="1.0"?>
<config>
    <modules>
        <ThomasRyan_Checkoutajax>
             <active>true</active>
             <codePool>local</codePool>
        </ThomasRyan_Checkoutajax>
    </modules>
</config>

This module naming looks incorrect - it is expected to be separated with an underscore indicating namespace -- so, not this:

<module>Checkoutajax</module>

All modules are named as Company_Module, etc. Checkoutajax_AjaxController is then not a valid classname. Check your general PHP error log (or Apache logs) and you should see something to the effect of class not exists.

Change/update this to ThomasRyan_Checkoutajax or similar. All instances of Checkoutajax will need to be updated in the module xml definition.

The frontName also has issues, namely, it should be lowercase:

<frontName>Checkoutajax</frontName>

I'm not sure if Magento forces the lowercase on the routename.

The updated code, then:

<?xml version="1.0"?>
<config>
  <modules>
    <ThomasRyan_Checkoutajax>
      <version>0.1.0</version>
    </ThomasRyan_Checkoutajax>
  </modules>
  <frontend>
    <routers>
      <Checkoutajax>
        <use>standard</use>
        <args>
          <module>ThomasRyan_Checkoutajax</module>
          <frontName>checkoutajax</frontName>
        </args>
      </Checkoutajax>
    </routers>
    <layout>
     <updates>
       <checkoutajax>
         <file>checkoutajax.xml</file>
       </checkoutajax>
     </updates>
   </layout>
 </frontend>
</config>

And the controller:

<?php

class ThomasRyan_Checkoutajax_AjaxController extends Mage_Core_Controller_Front_Action {

    public function indexAction() {
        $this->loadLayout();
        $this->renderLayout();
    }
}

Edit:

This is just a quick update to explain how routes/controllers/actions work in Magento. Let's say that this is your URL:

www.yourstore.com/checkoutajax/ajax/index

This represents three different entities:

• checkoutajax is the route name, also called frontName in the module definition XML
• ajax here represents the controller name. This controller file should be named AjaxController.php and located in the /controllers directory of your module.
• index represents the indexAction method.

So, to visualize:

www.yourstore.com/checkoutajax/ajax/index
---------route--------^
---------controller-------------^
---------action-----------------------^

1. Change your module's router configuration like this.

       <routers>
          <customajax>
            <use>standard</use>
            <args>
              <module>Custom_Customajax</module>
              <frontName>customajax</frontName>
            </args>
          </customajax>
       </routers>

Note the change that you made here is using customajax instead of Customajax. Now Magento will recognize your customajax_ajax_index layout handle.

2. Make sure your custom block exist. As per the definition in your layout XML file, Magento needs the following block class to be defined inside your module.

FILE : app\code\local\Custom/Customajax/Block/Customajax.php

<?php
class Custom_Customajax_Block_Customajax extends Mage_Core_Block_Template
{
}

Job is not over. Eventhough we defined our custom block, Magento do not know where exactly it needs to look for our custom block. So we need to tell to Magento that, "she" should look in our own module. For this add this code snippet in config.xml

<global>
    <blocks>
        <custom_customajax>
            <class>Custom_Customajax_Block</class>
        </custom_customajax>
    </blocks>
</global>

3. I am not sure about this point. You need to set url keyword like this

    url: "www.domain.com/customajax/ajax/index",

where www.domain.com is your site's base url.

You are done. Now clear the cache and then try again