Some magento functions are not working in outside magento(ajax page)

I am trying to use ajax to place the product list from particular attribute(manufacturer).

In my ajax page i try to use

$this->__('hi'); //not working

error

Fatal error: Using $this when not in object context in /home/shared/nftn/NFTN/js/ajax/ajax_designer.php on line 24

mage:__('hi'); //not working

error

Fatal error: Call to undefined method Mage::__() in /home/shared/nftn/开发者_JAVA百科NFTN/js/ajax/ajax_designer.php on line 23

i add required files in the top of the page

require "../../app/Mage.php";
umask(0);
Mage::app('default');
$layout = Mage::getSingleton('core/layout');

Even these functions also not working

Mage::stripTags()

Mage::getLayout()

What was the problem.How can i make it work

Thanks

---

Obviously $this has no meaning because you're not using it from within an object. All helpers have those functions, here I use 'core' because it is the most generic but if you're writing for your own module then use your module's helper - it helps with translation.

Mage::helper('core')->__('hello');
Mage::helper('core')->stripTags('world');

getLayout() cannot work from an external file because there is no router/controller/action associated with the page, hence no layout to use.

---

The longer but slightly more correct way would be to work with Magento's controllers rather than external files. Say your module is My_Module and the AJAX URL is www.example.com/mymodule/ajax/...

app/code/local/My/Module/etc/config.xml

<config>
    <frontend>
        <routers>
            <mymodule>
                <use>standard</use>
                <args>
                    <module>My_Module</module>
                    <frontName>mymodule</frontName>
                </args>
            </mymodule>
        </routers>
    </frontend>
</config>

app/code/local/My/Module/controllers/AjaxController.php

<?php

class My_Module_AjaxController extends Mage_Core_Controller_Front_Action
{
    public function indexAction()
    {
        $this->getResponse()->setBody($this->__('hi'));
    }
}

For a more complex example see Mage_CatalogSearch_AjaxController in app/code/core/Mage/CatalogSearch/controllers/AjaxController.php, it uses blocks as it's output which better follows the MVC paradigm.