Magento Development

Magento Controllers

Code Pools

Magento code pools are stored in app/code/ directory, it consists of:

• core: All the core Magento modules, DO NOT edit core code pools directly as it may break Magento installation due to incompatibilities etc.

• community: Modules by third-party codes, e.g. extensions

• local: Custom made modules, copy core modules here (preserving directory structure) if to modify the core modules instead of modifying core modules directly

Code pool execution priority (lowest to highest, find in next if module not found):

1. local
2. community
3. core
4. /app/lib

Namespaces (A.K.A Packages)

Fresh Magento core modules are stored app/code/core directory, "Mage" and "Zend" are 2 namespaces created by Magento. Creating namespaces for your custom modules are just to create a folder in app/code/local directory, it can be any name, e.g. Practice

Naming Conventions

• DO NOT include any "_" (underscore) for folder and file names, as it will be replaced by directory separator (DS) in Magento's autoloader
• Initial caps and camelcase for naming folders and classes
• Use "_" (underscore) in class names to specify path to class files e.g:
  • Magento expect "class Mage_Catalog_Block_Product_Widget_New" in class declaration to find the class file in Mage/Catalog/Block/Product/Widget/New.php

Magento's Autoloaders Class Initialization Steps:

1. "_" (underscores) are replaced by spaces
2. Convert all words to initial caps
3. Spaces are replaced by DS (directory separator)
4. Append .php

e.g. $instance = new Practive_ControllerTest_Model_MyClass() will be converted to Practice/ControllerTest/Model/MyClass.php where the class file is expected

Module Folder Structure

Directory structure for module "ControllerTest" (app/code/local/Practice/ControllerTest/) should contain the following directories:

• Block/
• controllers/
  • Optional as not all modules contain controllers
• etc/
  • Store module configuration and system files (expects .xml extension)
• Helper/
• Model/
• sql/

Configuration Files (Module Configuration)

• File can be any names as long as it end with xml
• Recommended naming conventions: Namespace_ModuleName.xml
• System wide configuration stored in app/etc/modules/ directory

Configuration Steps:

1. Create and edit app/etc/modules/Practice_ControllerTest.xml where Magento expects to find the module (ControllerTest) main config file in app/local/Practice/ControllerTest/etc/config.xml:

    <?xml version="1.0"?>
    <config>
        <modules>
            <Practice_ControllerTest>
               <active>true</active>  
               <codepool>local</codepool>
            </Practice_ControllerTest>
        </modules>
    </config>
   

2. Create and edit app/code/local/Practice/ControllerTest/etc/config.xml:

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

3. To define a controller, add the following code between "" tags after "" tags in app/code/local/Practice/ControllerTest/etc/config.xml:

    <frontend>
        <routers>
            <test_controller>
                <module>Practice_ControllerTest</module>  
                <frontName>requestflowtest</frontName>
            </test_controller>
        </routers>
    </frontend>
   

   • frontend => Specify an "area", possible values: frontend, backend or global
   • routers => A role
   • test_controller => Unique controller config

Creating a Controller

Create and edit app/code/local/Practice/ControllerTest/controllers/IndexController.php

class Practice_ControllerTest_IndexController extends
Mage_Core_Controller_Front_Action {
    public function indexAction() { echo "Hello World!"; }
}

Testing

Navigate to "//requestflowtest"

Routing

• To specify as admin router, use "admin" between the "" tags in config.xml, causing it to route for admin interface only
• To specify as frontend router, use "frontend" between "" tags in config.xml, causing it to route for frontend interface only

Order:

1. Admin
2. Standard
3. Cms
4. Default

Sample URL: http:////catalog/product/view/id/1

• catalog: frontName tag in config.xml
• product: ProductController
• catalog/product results: Mage/Catalog/controllers/ProductController.php
• view
  • viewAction() method in the controller
  • If viewAction() method not found, assume indexAction() in IndexController

Magento View

Layouts

Magento uses xml files to specify the layout, available handles for

<li>
    <label for="license_number"><?php echo $this->__('License Number') ?></label>
    <div class="input-box">
        <input type="text" name="license_number" id="license_number" value="<?php echo $this->escapeHtml($this->getFormData()->getLicenseNumber()) ?>" title="<?php echo $this->__('License Number') ?>" class="input-text" />
    </div>
</li>

<li>
    <label for="license_number"><?php echo $this->__('License Number') ?></label>
    <div class="input-box">
        <input type="text" name="license_number" id="license_number" value="<?php echo $this->htmlEscape($this->getCustomer()->getLicenseNumber()) ?>" title="<?php echo $this->__('License Number') ?>" class="input-text" />
    </div>
</li>

$installer = $this;
$installer->startSetup();
// Remove Product Attribute
$installer->removeAttribute('catalog_product', 'product_attribute_code');
// Remove Customer Attribute
$installer->removeAttribute('customer', 'customer_attribute_code');
$installer->endSetup();

<span class="value">  
<?php  
$quantity = Mage::getModel('cataloginventory/stock_item')->loadByProduct($_pro
duct)->getQty();  
if ($quantity > 0)  
     echo intVal($quantity);  
else  
     echo $this->helper('catalog')->__('In stock');  
?>  
</span>

<Practice_OneStepCheckout>  
    <depends>  
        <Mage_Sales />  
        <Mage_CatalogInventory />  
        <Mage_Checkout />  
    </depends>  
</Practice_OneStepCheckout>