Overwrite a controller and a block in magento

Question

I want to add a custom tab in catalog_product_edit page with my custom module. I want this tab of ajax type, since the tab holds grid content.

To achieve this I rewrite the Mage/Adminhtml/Block/Catalog/Product/Edit/Tabs.php block with my Mysite/Combooffers/Block/Adminhtml/Catalog/Product/Edit/Tabs.php block. It successfully rewrote the core block. My custom tab appeared in the edit page, but while click on the tab, it didnt work properly.

I have gone through the core files, and I found that, for ajax tabs, the action is defined in the controller Mage/Adminhtml/controllers/Catalog/ProductController.php. So I assumed the problem occurs due to my tabs action is not present in the core controller. So I planned to rewrite the above controller with myown Mysite/Combooffers/controllers/Adminhtml/Catalog/ProductController.php. When I rewrote the controller, edit page now shows nothing.

my app/code/local/Mysite/Combooffers/etc/config.xml

<config>
<modules>
 <Mysite_Combooffers>
 <version>0.1.0</version>
 </Mysite_Combooffers>
</modules>
<frontend>
 <routers>
 <Combooffers>
 <use>standard</use>
 <args>
 <module>Mysite_Combooffers</module>
 <frontName>combooffers</frontName>
 </args>
 </Combooffers>
 </routers>
 <layout>
 <updates>
 <combooffers>
 <file>combooffers.xml</file>
 </combooffers>
 </updates>
 </layout>
</frontend>
<admin>
 <routers>
 <adminhtml>
 <args>
 <modules>
 <Mysite_Combooffers before="Mage_Adminhtml">Mysite_Combooffers_Adminhtml</Mysite_Combooffers>
 </modules>
 </args>
 </adminhtml>
 </routers>
</admin>
<adminhtml>
 <layout>
 <updates>
 <combooffers>
 <file>combooffers.xml</file>
 </combooffers>
 </updates>
 </layout>
</adminhtml>
<global>
 <blocks>
 <combooffers>
 <class>Mysite_Combooffers_Block</class>
 <sort_order>200</sort_order>
 </combooffers>
 <adminhtml> 
 <rewrite> 
 <catalog_product_edit_tabs>
 Mysite_Combooffers_Block_Adminhtml_Catalog_Product_Edit_Tabs
 </catalog_product_edit_tabs> 
 </rewrite> 
 </adminhtml>
 </blocks>
 <routers>
 <adminhtml>
 <rewrite>
 <mysite_combooffers_adminhtml_catalog_product>
 <from><![CDATA[#^admin/catalog_product/$#]]></from>
 <to>/admin/catalog_product/</to>
 </mysite_combooffers_adminhtml_catalog_product>
 </rewrite>
 </adminhtml>
 </routers>
 <helpers>
 <combooffers>
 <class>Mysite_Combooffers_Helper</class>
 </combooffers>
 </helpers>
</global>
</config>

app/code/local/Mysite/Combooffers/Block/Adminhtml/Catalog/Product/Edit/Tabs.php

<?php
class Mysite_Combooffers_Block_Adminhtml_Catalog_Product_Edit_Tabs extends Mage_Adminhtml_Block_Catalog_Product_Edit_Tabs
{
 protected function _prepareLayout()
 {
 /**Loads our tab using ajax.
 * ajax tab loads while click on the tab on edit page. Normally use to load grid content.
 * its complex
 * url is the important one. when click on the tab, it will search for action correspond to the url in the controller.
 * here the action name should be `comboofferAction()`
 */
 $this->addTab('combooffer', array(
 'label' => Mage::helper('catalog')->__('Combo Products'),
 'url' => $this->getUrl('*/*/combooffer', array('_current' => true)),
 'class' => 'ajax',
 'after' => 'crosssell', //this will set tab after cross-sell tab.
 ));
 return parent::_prepareLayout();
 }
} 

app/code/local/Mysite/Combooffers/Block/Adminhtml/Catalog/Products/Edit/Tab/Combooffer.php

<?php
 class Mysite_Combooffers_Block_Adminhtml_Catalog_Product_Edit_Tab_Combooffer extends Mage_Adminhtml_Block_Widget_Form
 {
/**
 * Set grid params
 *
 */
public function __construct()
{
 parent::__construct();
 $this->setId('combo_offers_product_grid');
 $this->setDefaultSort('entity_id');
 $this->setUseAjax(true); // Using ajax grid is important
 if ($this->_getProduct()->getId()) {
 $this->setDefaultFilter(array('in_products'=>1)); // By default we have added a filter for the rows, 
 //that in_products value to be 1
 }
 // if ($this->isReadonly()) {
 // $this->setFilterVisibility(false);
 //}
 $this->setSaveParametersInSession(false); //Dont save paramters in session or else it creates problems
}
/**
 * Retirve currently edited product model
 *
 * @return Mage_Catalog_Model_Product
 */
protected function _getProduct()
{
 return Mage::registry('current_product');
}
/**
 * Add filter
 *
 * @param object $column
 * @return Mysite_Combooffers_Adminhtml_Block_Catalog_Product_Edit_Tab_Combooffer
 */
protected function _addColumnFilterToCollection($column)
{
 // Set custom filter for in product flag
 if ($column->getId() == 'in_products') {
 $productIds = $this->_getSelectedComboOffers();
 if (empty($productIds)) {
 $productIds = 0;
 }
 if ($column->getFilter()->getValue()) {
 $this->getCollection()->addFieldToFilter('entity_id', array('in'=>$productIds));
 } else {
 if($productIds) {
 $this->getCollection()->addFieldToFilter('entity_id', array('nin'=>$productIds));
 }
 }
 } else {
 parent::_addColumnFilterToCollection($column);
 }
 return $this;
}
/**
 * Prepare collection
 *
 * @return Mage_Adminhtml_Block_Widget_Grid
 */
protected function _prepareCollection()
{
 $collection = Mage::getModel('catalog/product_link')->useUpSellLinks()
 ->getProductCollection()
 ->setProduct($this->_getProduct())
 ->addAttributeToSelect('*');
 if ($this->isReadonly()) {
 $productIds = $this->_getSelectedProducts();
 if (empty($productIds)) {
 $productIds = array(0);
 }
 $collection->addFieldToFilter('entity_id', array('in'=>$productIds));
 }
 $this->setCollection($collection);
 return parent::_prepareCollection();
}
/**
 * Add columns to grid
 *
 * @return Mage_Adminhtml_Block_Widget_Grid
 */
protected function _prepareColumns()
{
 if (!$this->_getProduct()->getUpsellReadonly()) {
 $this->addColumn('in_products', array(
 'header_css_class' => 'a-center',
 'type' => 'checkbox',
 'name' => 'in_products',
 'values' => $this->_getSelectedComboOffers(),
 'align' => 'center',
 'index' => 'entity_id'
 ));
 }
 $this->addColumn('entity_id', array(
 'header' => Mage::helper('catalog')->__('ID'),
 'sortable' => true,
 'width' => 60,
 'index' => 'entity_id'
 ));
 $this->addColumn('name', array(
 'header' => Mage::helper('catalog')->__('Name'),
 'index' => 'name'
 ));
 $this->addColumn('type', array(
 'header' => Mage::helper('catalog')->__('Type'),
 'width' => 100,
 'index' => 'type_id',
 'type' => 'options',
 'options' => Mage::getSingleton('catalog/product_type')->getOptionArray(),
 ));
 $sets = Mage::getResourceModel('eav/entity_attribute_set_collection')
 ->setEntityTypeFilter(Mage::getModel('catalog/product')->getResource()->getTypeId())
 ->load()
 ->toOptionHash();
 $this->addColumn('set_name', array(
 'header' => Mage::helper('catalog')->__('Attrib. Set Name'),
 'width' => 130,
 'index' => 'attribute_set_id',
 'type' => 'options',
 'options' => $sets,
 ));
 $this->addColumn('status', array(
 'header' => Mage::helper('catalog')->__('Status'),
 'width' => 90,
 'index' => 'status',
 'type' => 'options',
 'options' => Mage::getSingleton('catalog/product_status')->getOptionArray(),
 ));
 $this->addColumn('visibility', array(
 'header' => Mage::helper('catalog')->__('Visibility'),
 'width' => 90,
 'index' => 'visibility',
 'type' => 'options',
 'options' => Mage::getSingleton('catalog/product_visibility')->getOptionArray(),
 ));
 $this->addColumn('sku', array(
 'header' => Mage::helper('catalog')->__('SKU'),
 'width' => 80,
 'index' => 'sku'
 ));
 $this->addColumn('price', array(
 'header' => Mage::helper('catalog')->__('Price'),
 'type' => 'currency',
 'currency_code' => (string) Mage::getStoreConfig(Mage_Directory_Model_Currency::XML_PATH_CURRENCY_BASE),
 'index' => 'price'
 ));
 $this->addColumn('position', array(
 'header' => Mage::helper('catalog')->__('Position'),
 'name' => 'position',
 'type' => 'number',
 'width' => 60,
 'validate_class' => 'validate-number',
 'index' => 'position',
 'editable' => true, //!$this->_getProduct()->getUpsellReadonly(),
 'edit_only' => true //!$this->_getProduct()->getId()
 ));
 return parent::_prepareColumns();
}
/**
 * Rerieve grid URL
 *
 * @return string
 */
public function getGridUrl()
{
 return $this->_getData('grid_url') ? $this->_getData('grid_url') : $this->getUrl('*/*/combooffer', array('_current'=>true));
}
/**
 * Retrieve selected combo offers
 *
 * @return array
 */
protected function _getSelectedComboOffers()
{
 $products = $this->getSelectedComboOffers();
 if (!is_array($products)) {
 $products = array_keys($this->getSelectedComboOffers());
 }
 return $products;
}
/**
 * Retrieve combo offers
 *
 * @return arraygetSelectedComboOffers
 */
public function getSelectedComboOffers()
{
 $products = array();
 foreach (Mage::registry('current_product')->getUpSellProducts() as $product) {
 $products[$product->getId()] = array('position' => $product->getPosition());
 }
 return $products;
}

}

app/code/local/Mysite/Combooffers/controllers/Adminhtml/Catalog/ProductController.php

<?php
require_once('Mage/Adminhtml/controllers/Catalog/ProductController.php');
class Mysite_Combooffers_Adminhtml_Catalog_ProductController extends Mage_Adminhtml_Catalog_ProductController
{
 /** Use to set content of combo offer tab.
 * Defines layout of combo offer tab.
 * The layout defined here should present in app/design/adminhtml/default/default/<layout>.xml
 */
 public function comboofferAction()
 {
 $this->_initProduct();
 $this->loadLayout();
 $this->getLayout()->getBlock('catalog.product.edit.tab.combooffer')
 ->setProductsUpsell($this->getRequest()->getPost('products_combooffer', null));
 $this->renderLayout();
 }
}

app/design/adminhtml/default/default/layout/combooffers.xml

<combooffers_adminhtml_combooffer_combooffer>
<adminhtml_catalog_product_upsell>
 <block type="core/text_list" name="root" output="toHtml">
 <block type="adminhtml/catalog_product_edit_tab_upsell" name="catalog.product.edit.tab.combooffer"/>
 <block type="adminhtml/widget_grid_serializer" name="upsell_grid_serializer">
 <reference name="upsell_grid_serializer">
 <action method="initSerializerBlock"> 
 <grid_block_name>catalog.product.edit.tab.combooffer</grid_block_name>
 <data_callback>getSelectedComboOffers</data_callback>
 <hidden_input_name>links[combooffers]</hidden_input_name>
 <reload_param_name>products_combooffer</reload_param_name>
 </action>
 <action method="addColumnInputName">
 <input_name>position</input_name>
 </action>
 </reference>
 </block>
 </block>
</adminhtml_catalog_product_upsell>
</combooffers_adminhtml_combooffer_combooffer>

Is there any problem with my approach ? Am I in the right path? What is the error that I have made here? Please give your suggestions. Thanks in advance

Answer 1

It would be easier if you'd change url for ajax call on tab In

$this->addTab('combooffer', array(
 'label' => Mage::helper('catalog')->__('Combo Products'),
 'url' => $this->getUrl('*/*/combooffer', array('_current' => true)),
 'class' => 'ajax',
 'after' => 'crosssell', //this will set tab after cross-sell tab.
 ));

url key is creating the path for ajax call. Asteriks means to use the same as current, so */*/combooffer is translated to admin/catalog_product/combooffer. You can change it to */my_controller/combooffer and it should work.

So change file app/code/local/Mysite/Combooffers/controllers/Adminhtml/Catalog/ProductController.php to app/code/local/Mysite/Combooffers/controllers/Adminhtml/Catalog/ComboofferController.php so it would not overwrite core controller and make it extend Mage_Adminhtml_Controller_Action

and in app/code/local/Mysite/Combooffers/Block/Adminhtml/Catalog/Product/Edit/Tabs.php use code: 'url' => $this->getUrl('*/catalog_combooffer/combooffer', array('_current' => true)),

• Rajeev K Tomy: I have tried your suggestion. It didnt work. Please not that, my edit page does not show any tabs, while I am trying to extend controller. But If I am overwriting block only, all tabs including my tab is displaying and all other tabs except mine are working perfectly. So when I extend controller, eventhough I am including the default controller in my controller file, it does not working. Thats why tabs are not present in edit page.

Answer 2

Isn't deprecated (after Magento 1.4 or greater) this:

<routers>
 <adminhtml>
 <rewrite>

You need only:

<admin>
 <routers>
 <adminhtml>
 <args>
 <modules>
 <Mysite_Combooffers before="Mage_Adminhtml">Mysite_Combooffers_Adminhtml</Mysite_Combooffers>

Add a function from the core controller in your controller and add a debug message as first line inside function: with exit(..); - to see if your controller is used.

Answer 3

I think the error is caused by the require statement. Try this:

require_once Mage::getModuleDir('controllers', 'Mage_Adminhtml').DS.'Catalog'.DS.'ProductController.php';

• Rajeev K Tomy: I have used this one. After going through several tutorials, I notice that, most of them use the method that I have used above. Do you see any other errors ?
• user4351: Not really, but since you get a blank page, it must be an error early in the stack. Anything in logs?
• Rajeev K Tomy: nope. I have one doubt. Is it necessary to overwrite the controller file. Can I use my controller directly (Block/Adminhtml/CombooffersContoller.php) to define the action for ajax tab. Do you have any idea about it?
• user4351: Sorry for the delay. Is this still an issue or did you solve it? I'll try to reproduce locally now if it isn't solved yet.

Answer 4

This part was the villain in my case

 <adminhtml> 
 <rewrite> 
 <catalog_product_edit_tabs>
 Mysite_Combooffers_Block_Adminhtml_Catalog_Product_Edit_Tabs
 </catalog_product_edit_tabs> 
 </rewrite> 
 </adminhtml>

As you can see, I have put unwanted spaces inside the node <catalog_product_edit_tabs /> and thats what make problem in my case.

So it should be like this.

 <adminhtml> 
 <rewrite> 
 <catalog_product_edit_tabs>Mysite_Combooffers_Block_Adminhtml_Catalog_Product_Edit_Tabs</catalog_product_edit_tabs> 
 </rewrite> 
 </adminhtml>

• Timon de Groot: Whitespace is evil in xml