Magento Can'；t使用观察者事件渲染布局

我正在尝试加载布局，并在购物车页面后设置自定义phtml

但是，当我放置加载布局的指令时，出现以下错误：

Fatal error: Call to a member function getRequestedRouteName() on a non-object in /var/www/html/magento/edubras.dev/html/app/code/core/Mage/Core/Controller/Varien/Action.php on line 226

config.xml：

<?xml version="1.0"?>
<config>
    <modules>
        <GrupoNDB_EmailCatcher>
            <version>0.0.1</version>
        </GrupoNDB_EmailCatcher>
    </modules>

    <global>
        <blocks>
            <grupondb_emailcatcher>
                <class>GrupoNDB_EmailCatcher_Block</class>
            </grupondb_emailcatcher>
        </blocks>
        <helpers>
            <grupondb_emailcatcher>
                <class>GrupoNDB_EmailCatcher_Helper</class>
            </grupondb_emailcatcher>
        </helpers>

        <models>
            <grupondb_emailcatcher>
                <class>GrupoNDB_EmailCatcher_Model</class>
            </grupondb_emailcatcher>
        </models>
        <events>
            <controller_action_predispatch_onestepcheckout_index_index>
                <observers>
                    <grupondb_emailcatcher>
                        <class>grupondb_emailcatcher/observer</class>
                        <method>displayEmailCatcherPage</method>
                    </grupondb_emailcatcher>
                </observers>
            </controller_action_predispatch_onestepcheckout_index_index>
        </events>
    </global>
</config>

0.0.1
GrupoNDB_电子邮件捕获器_块
GrupoNDB\u EmailCatcher\u助手
GrupoNDB_EmailCatcher_模型
grupondb_电子邮件捕获者/观察员
显示电子邮件捕获器页面

我的观察员代码：

<?php 

class GrupoNDB_EmailCatcher_Model_Observer {

    public function __construct() {

    }


    public function displayEmailCatcherPage($observer) {

        $frontA = new Mage_Core_Controller_Front_Action;
        $frontA->loadLayout()->getLayout();

        $eCookie = Mage::getModel('core/cookie')->get("email");

        if( $eCookie == 'none'|| !isset($eCookie) || empty($eCookie) ) {
            echo Mage::app()->getLayout()->createBlock('core/template')->setTemplate('grupondb/email-catcher/cadastroEmail.phtml')->toHtml();
            die;
        }

        // Call the block to fill the fields in checkout
        echo Mage::app()->getLayout->createBlock('core/template')->setTemplate('grupondb/email-catcher/set-email-field.phtml')->toHtml();


    }

}