Problem with loading Grid in the Admin area

Question

Folder Structure:

Companyname/Products/Block/Adminhtml/Products.php

class Companyname_Products_Block_Adminhtml_Products extends Mage_Adminhtml_Block_Widget_Grid_Container {
 public function __construct() {
 $this->_controller = 'adminhtml_products';
 $this->_blockGroup = 'companyname_products';
 $this->_headerText = Mage::helper('companyname_products')->__('Books Manager');
 $this->_addButtonLabel = Mage::helper('companyname_products')->__('Add Book');
 parent::__construct();
 }
}

Companyname/Products/Block/AdminHtml/Products/Grid.php

class Companyname_Products_Block_Adminhtml_Products_Grid extends Mage_Adminhtml_Block_Widget_Grid {
 public function __construct() {
 parent::__construct();
 $this->setId('booksGrid');
 $this->setDefaultSort('product_id');
 $this->setDefaultDir('ASC');
 $this->setSaveParametersInSession(true);
 }
 protected function _prepareCollection() {
 $collection = Mage::getModel('companyname_products/products')->getCollection();
 $this->setCollection($collection);
 return parent::_prepareCollection();
 }
 protected function _prepareColumns() {
 $this->addColumn('product_id', array(
 'header' => Mage::helper('companyname_products')->__('ID'),
 'align' => 'left',
 'width' => '10px',
 'index' => 'product_id',
 ));
 $this->addColumn('updated_at', array(
 'header' => Mage::helper('companyname_products')->__('Updated At'),
 'align' => 'left',
 'index' => 'updated_at',
 'width' => '20px',
 ));
 $this->addColumn('format', array(
 'header' => Mage::helper('companyname_products')->__('Format'),
 'width' => '10px',
 'index' => 'format',
 ));
 $this->addColumn('sku', array(
 'header' => Mage::helper('companyname_products')->__('Sku'),
 'width' => '30px',
 'index' => 'sku',
 ));
 $this->addExportType('*/*/exportCsv', Mage::helper('companyname_products')->__('CSV'));
 return parent::_prepareColumns();
 }
 protected function _prepareMassaction() {
 }
 public function getRowUrl($row) {
 return $this->getUrl('*/*/edit', array('id' => $row->getProductId()));
 }
}

etc/config.xml

<config>
 <modules>
 <companyname_Products>
 <version>0.1.0</version>
 </companyname_Products>
 </modules>
 <global>
 <helpers>
 <companyname_products>
 <class>companyname_Products_Helper</class>
 </companyname_products> 
 </helpers>
 <blocks>
 <companyname_products>
 <class>companyname_Products_Block</class>
 </companyname_products>
 </blocks>
 <models>
 <companyname_products>
 <class>companyname_Products_Model</class>
 <resourceModel>companyname_products_mysql4</resourceModel>
 </companyname_products>
 <companyname_products_mysql4>
 <class>companyname_Products_Mysql4</class>
 <entities>
 <books>
 <table>companyname_products_books</table>
 </books>
 </entities>
 </companyname_products_mysql4> 
 </models>
 <resources>
 <companyname_products_setup>
 <setup>
 <module>companyname_Products</module>
 <class>companyname_Products_Model_Resource_Setup</class>
 </setup>
 <connection>
 <use>core_setup</use>
 </connection>
 </companyname_products_setup>
 <companyname_products_write>
 <connection>
 <use>core_write</use>
 </connection>
 </companyname_products_write>
 <companyname_products_read>
 <connection>
 <use>core_read</use>
 </connection>
 </companyname_products_read>
 </resources>
 </global>
 <admin>
 <routers>
 <adminhtml>
 <args>
 <modules>
 <companyname_products before="Mage_Adminhtml">companyname_Products_Adminhtml</companyname_products>
 </modules>
 </args>
 </adminhtml>
 </routers>
 </admin>
 <adminhtml>
 <layout>
 <updates>
 <companyname_products module="companyname_products">
 <file>companyname_products.xml</file>
 </companyname_products>
 </updates>
 </layout>
 </adminhtml>
</config>

etc/adminhtml.xml

<config>
 <menu>
 <companyname_products translate="title" module="companyname_products">
 <title>Upload Books</title>
 <sort_order>71</sort_order>
 <children>
 <items module="companyname_products">
 <title>Manage Books</title>
 <sort_order>0</sort_order>
 <action>adminhtml/books/index</action>
 </items>
 </children>
 </companyname_products>
 </menu>
 <acl>
 <resources>
 <admin>
 <children>
 <companyname_products translate="title" module="companyname_products">
 <title>Upload Books</title>
 <sort_order>300</sort_order>
 <children>
 <items translate="title" module="companyname_products">
 <title>Manage Books</title>
 <sort_order>0</sort_order>
 </items>
 </children>
 </companyname_products>
 </children>
 </admin>
 </resources>
 </acl>
</config>

If you see errors in the xml files that has to do with uppercase letters ignore them.They are correct in the original file.

My problem and my question is: The link Upload Books is there.The acl permissions are working fine.The database is created correctly.The grid container is created BUT not the grid itself. I get a page with the Add Book button and Manage Books label and not the grid.I also can echo through the function _prepareColumns() text..And i checked and the grid.phtml is loading and my Block. I use v1.8.1 magento on Xampp. Thanks a lot!

========================= EDIT ===========================

After many hours i realized that the problem is coming from the database. if i do that:

 protected function _prepareCollection() {
 $collection = Mage::getModel('companyname_books/books')->getCollection();
 var_dump($collection);
 $this->setCollection($collection);
 return parent::_prepareCollection();
 }

The result is bool(false). But from the way I am making a database I can't really find a problem. Here is how I am doing them.

Model/Products.php

class Companyname_Products_Model_Books extends Mage_Core_Model_Abstract
{
 public function __construct() {
 $this->_init('comapnyname_products/books');
 parent::_construct();
 } 
}

Model/Mysql4/Products.php

class Companyname_Books_Model_Mysql4_Products extends Mage_Core_Model_Mysql4_Abstract {
 public function _construct() {
 $this->_init('comapnyname_products/books', 'book_id');
 }
}

Collection.php

class Companyname_Books_Model_Mysql4_Products_Collection extends Mage_Core_Model_Mysql4_Collection_Abstract {
 public function _construct() {
 $this->_init('comapnyname_products/books');
 parent::_construct();
 }
}

• Marius: Not sure if this is the issue (most probably not) but rename the folder AdminHtml to Adminhtml
• vbak: It is Adminhtml.My bad when i was making the post.As i mention everything apart from the grid itself is working.
• Marius: I don't know that the issue is but here is how you can debug. Temporary create a method in your container block that looks like this: protected function _prepareLayout(){echo get_class($this->getLayout()->createBlock( $this->_blockGroup.'/' . $this->_controller . '_grid'); exit;} See what that echos. It should show Companyname_Products_Block_Adminhtml_Products_Grid if everything is correct. Also check the var/log for error messages.

Answer 1

I think this is preventing it from working.
In the config.xml you declared your resource node like this:

<companyname_products_mysql4>
 <class>companyname_Products_Mysql4</class>
 <entities>
 <books>
 <table>companyname_products_books</table>
 </books>
 </entities>
</companyname_products_mysql4> 

The <class> tag is wrong. It should be

<class>Companyname_Products_Model_Mysql4</class>

• vbak: Yes,I found it too..Sharp eye though!