1. Add new fields in config xml (app\code\core\Mage\Customer\etc\config.xml). If you create new module then you can add this xml block in module config xml file. Create new module is the best practice and recommended

<?xml version="1.0"?>
<fieldsets>
   <customer_account>
     <prefix><create>1</create><update>1</update><name>1</name></prefix>
     <firstname><create>1</create><update>1</update><name>1</name></firstname>
     <middlename><create>1</create><update>1</update><name>1</name></middlename>
     <lastname><create>1</create><update>1</update><name>1</name></lastname>
     <suffix><create>1</create><update>1</update><name>1</name></suffix>
     <email><create>1</create><update>1</update></email>
     <password><create>1</create></password>
     <confirmation><create>1</create></confirmation>
     <dob><create>1</create><update>1</update></dob>
     <taxvat><create>1</create><update>1</update></taxvat>
     <gender><create>1</create><update>1</update></gender>

     /* newly added field(s)*/
     <accounttype><create>1</create><update>1</update><name>1</name></accounttype>
     <companyname><create>1</create><update>1</update><name>1</name></companyname>
  </customer_account>
</fieldsets>

2. Add these extra field(s) in your respective theme registration.phtml (app\design\frontend\…\…\template\customer\form\registration.phtml). Keep the field name same as you mentioned in config.xml

3. To save extra data in database with customer registration process you have to add these extra field(s) as entity attribute in eav_attribute table. Here is sql script.

insert into `magento`.`eav_attribute` (`entity_type_id`, `attribute_code`, `attribute_model`, `backend_model`, `backend_type`, `backend_table`, `frontend_model`, `frontend_input`, frontend_label`, `frontend_class`, `source_model`, `is_required`, `is_user_defined`, `default_value`, `is_unique`, `note`)
values(1, 'accounttype', '', '', 'varchar', '', '', 'select', 'Account Type', '', '', 0, 0, '', 0,''),
        (1, 'companyname', '', '', 'varchar', '', '', 'text', 'Company Name', '', '', 0, 0, '', 0,'');

That’s all. Try and let me know if you face any complexity.

Like this you can add extra field(s) in any magento pages as well.

For a recent project I had to create a custom order processing module in magento. I got help from a post of magento forum ( http://www.magentocommerce.com/boards/viewthread/28426/). That was nice and very helpful for me. And it saved my time as well. So my heartiest thanks to all of the guys who have been contributed in that forum post.

But I faced problem to add option(s) with order item. I found a solution to add option(s) to quote object. But using this you can order only single item at a time. Below is the code snap.

$option = array('options'=>array(
              "option_id1" => 'option_value1',
              "option_id2" => 'option_value2'
             ));

$request = new Varien_Object();
 $request->setData($option);
$quoteObj->addProduct($productObj,$request);

To order multiple items at a time you have to add option(s) with quote item object. Here is the code snap for your help.

$quoteObj=Mage::getModel('sales/quote')->assignCustomer($customerObj);
$productModel=Mage::getModel('catalog/product');

foreach($products as $product) {
	$productObj = $productModel->load($productId);
	$quoteItem = Mage::getModel('sales/quote_item')->setProduct($productObj);

	$quoteItem->addOption(new Varien_Object(
                   	array(
                      		'product' => $quoteItem->getProduct(),
                       		'code' => 'option_ids',
                       		'value' => $option_id  // 45,46,55
               	         )
               	));

	$quoteItem->addOption(new Varien_Object(
                    	array(
                       		'product' => $quoteItem->getProduct(),
                       		'code' => 'option_'.$option_id,   //45
                       		'value' => $option_value          // ‘White’
             	         )
   		));

        $quoteItem->addOption(new Varien_Object(
                    	array(
                       		'product' => $quoteItem->getProduct(),
                       		'code' => 'option_'.$option_id,   //46
                       		'value' => $option_value         // ‘Large’
               	        )
   		));

	$quoteItem->setQuote($quoteObj);
	$quoteItem->setQty($Quantity);
	$quoteObj->addItem($quoteItem);
}
$quoteObj->collectTotals();
$quoteObj->save();

This code snap has been worked so far. For more details and any kind of helps contact with me.

We can handle tier price in many ways. Here I am describing basic logic to add/update tier price in modular way. At first define all tier prices as an array. Ofcourse mind one thing about quantity. Quantity format must be four decimal precision. Like 100.0000. For this you can use below formatting.

$qty = number_format($qty, 4, ‘.’, ”);

//Define tier price as an array
$tierPrices[] = array(
		     'website_id'  => 0,
		     'cust_group'  => $customer_group_id,
		     'price_qty'   => $qty,
		     'price'       => $price 
		   );

Ex.
$tierPrices[0] = array(
		     'website_id'  => 0,
		     'cust_group'  => 1,
		     'price_qty'   => 100.0000,
		     'price'       => 12.0000 
		   );

$tierPrices[1] = array(
		     'website_id'  => 0,
		     'cust_group'  => 2,
		     'price_qty'   => 100.0000,
		     'price'       => 10.0000 
		   );


//get productid for corresponding SKU.
$productid = Mage::getModel('catalog/product')
                  ->getIdBySku($sku);

// Initiate product model 
$product = Mage::getModel('catalog/product');

// Load specific product whose tier price want to update
$product ->load($productid);

// take existing tier prices of that product
$existingTierPrice = $product->tier_price;
		
// Marge existing and new tier prices to update
$tierPrices=array_merge($existingTierPrice,$newTierPrices);
		
// Assign all tier prices to product's tier_price object
$product->tier_price = $tierPrices;

// Save you product with all tier prices
$product->save(); 

Also Magento has web service API support to handle tier price. If you are expert in web service work then you can do the same thing using Magento API. To handle tier price with api call do something like below.

$proxy = new SoapClient('http://127.0.0.1/magento/api/soap/?wsdl');
$sessionId = $proxy->login('apiUser', 'apiKey');
 
// Get tier prices
$tierPrices = $proxy->call($sessionId, 'product_tier_price.info', 'Sku');
 
// Add new
$tierPrices[] = array(
    'website'           => 'all',
    'customer_group_id' => 'all',
    'qty'               => 68,
    'price'             => 18.20
);
 
// Update tier prices
$proxy->call($sessionId, 'product_tier_price.update', array('Sku', $tierPrices));

Setup API: At first create api user and api key from Magento’s admin. Follow below steps.
1. Create api user from admin->system->web services-> Users->Add New User->User Info. See picture.

Api user create with api key

2. Create role to set permission on api method under admin->system->web services-> Roles->Add New Role.
3. Define “Role Resources” for created role. See picture.

Set api permission on role

4. Set “User Role” from admin->system->web services-> Users->choose user->User Role.

Call API:
API user and key is created. Now we can call api methods in two ways.
1. Soap call
2. V2_Soap call

Here I am going to discuss both ways.

Soap call:
Magento wiki and help center have described this method. So who are beginner in web service work they can call magento api using this soap method. You get all api documentations in Magento site. Here is an example.

//create soap object
$proxy = new SoapClient('http://127.0.0.1/magento/api/soap/?wsdl');

// create authorized session id using api user name and api key
// $sessionId = $proxy->login('apiUser', 'apiKey');
$sessionId = $proxy->login('m4u_admin', '12345678');

 // Get customer info for customer id = 1
$customerinfo = $proxy->call($sessionId, 'customer.info', 1);

print_r($customerinfo);

V2_Soap call:
V2_soap call is for advance user. Who are expert in web service work they can easily use this method to call any magento api method from remote place. Whose magento knowledge is zero they also can use this soap method to work with magento web service. But about this method you will not get any api documentation in Magento wiki. But I think it will easy for you.

Here I am going to describe a-z about v2_soap method as any beginner also can use this soap calling method.

//create soap object
$proxy = new SoapClient('http://127.0.0.1/magento/api/v2_soap/?wsdl');

// create authorized session id using api user name and api key
// $sessionId = $proxy->login('apiUser', 'apiKey');
$sessionId = $proxy->login('m4u_admin', '12345678');

 // Get customer info for customer id = 1
$customerinfo = $proxy->customerCustomerInfo($sessionId,1);

print_r($customerinfo);

Which method you need to call?

At first decide which method you need to call of api. Suppose you want to retrieve customer info from Magento store. So you should call customer related api method to get customer info. But you donot know which method exactly you need. To view all available methods in your magento api please run http://127.0.0.1/magento/api/v2_soap/?wsdl. Now pick appropriate api method from wsdl operation list. Suppose I pick “customerCustomerInfo” method to get customer info.

<operation name="customerCustomerInfo">
   <documentation>Retrieve customer data</documentation> 
   <input message="typens:customerCustomerInfoRequest"/>
   <output message="typens:customerCustomerInfoResponse"/>
</operation>

What is request parameter?

From wsdl you get a clear concept about api request/input parameter. For “customerCustomerInfo” operation input message is “customerCustomerInfoRequest”. So you will get all input/request parameter info (name and type) to call customerCustomerInfo method in message “customerCustomerInfoRequest”. customerCustomerInfo has three request parameter such sessionid(string), customerid(int) and atribuates(Array).

<message name="customerCustomerInfoRequest"> 
    <part name="sessionId" type="xsd:string"/>
    <part name="customerId" type="xsd:int"/>
    <part name="attributes" type="typens:ArrayOfString"/>
</message>   

So we can request customerCustomerInfo method as below.

// Get customer info for customer id = 1 and attribute is optional
$attribute = array(‘firstname’, ‘lastname’, ‘email’, ‘store_id’);
$customerinfo = $proxy->call($sessionId, ‘customer.info’, 1, $attribute);

see picture for details-

API v2_soap wsdl request and response message.

What is return/response data?

From wsdl you also get idea about api response/return/output. For “customerCustomerInfo” operation output message is “customerCustomerInfoResponse”. So you will get output/result info (name and type) of customerCustomerInfo method in message “customerCustomerInfoResponse”. customerCustomerInfo will return customerCustomerEntity object as data. Please see what the format of customerCustomerEntity object in wsdl.

<message name="customerCustomerInfoResponse">
    <part name="customerInfo" type="typens:customerCustomerEntity"/>
</message>

That’s it!!

In two ways we can update magento’s inventory.
1. By creating new module or
2. Using product API/web service.

Here I will discuss update through module system.

Update inventory creating new module:

At first create new module in local pool to handle inventory update work. And create all of your necessary files. Then follow below steps to update your inventory.

Load product: load product using product id. If you have product sku then retrieve product id for corresponding sku.

// retrieve product id using sku
 $product_id = Mage::getModel('catalog/product')
                    ->getIdBySku($sku);

// call product model and create product object
$product    = Mage::getModel('catalog/product');
// Load product using product id
 $product ->load($product_id);

Set updated inventory data: set all of your updated data in product object.

// get product's general info such price, status, description
$productInfoData = $product->getData();

// update general info using new data
$productInfoData['price'] = 11;
$productInfoData['description'] = 'Testing product update';
$productInfoData['status'] = 1;

// then set product's general info to update
$product->setData($productInfoData);

// get product's stock data such quantity, in_stock etc
$stockData = $product->getStockData();

// update stock data using new data
$stockData['qty'] = 356;
$stockData['is_in_stock'] = 1;

// then set product's stock data to update
$product->setStockData($stockData);

// call save() method to save your product with updated data
$product->save();

Basically our product update process is completed but in this situation updated product will not be save. Magento want origData to save product object. Without admin session magento cannot create origData for product. This is a magento security issue. So if you want to update magento product outside of admin or without creating admin session then you need to override Mage_Catalog_Model_Product class.

Configure new module and create app/local/M4U/catalog/etc/c onfig.xml file and write below code.

<?xml version="1.0"?>
<config> 
    <global>
	<modules>
           <m4u_catalog>
               <version>0.1.0</version>
           </m4u_catalog>
        </modules>
	<models>
	  <catalog>
            <rewrite>
              <product>M4U_Catalog_Model_Product</product>
            </rewrite>
          </catalog>
       </models> 
   </global>	
</config>

Override Mage_Catalog_Model_Product class and write setOrigData method as below.

class M4U_Catalog_Model_Product extends Mage_Catalog_Model_Product
{
    /**
     * Set original loaded data if needed
     * @param string $key
     * @param mixed $data
     * @return Varien_Object
     */
    public function setOrigData($key=null, $data=null)
    {
       return Mage_Catalog_Model_Abstract::setOrigData($key, $data);
    }
}

If you expert in Magento module system or in override system only then you can follow this process to update magento inventory otherwise you should proceed with api. For alternative solution, you can see “update product through api / web service” post.

Have any query or question? Feel free to post.

Magento cms module has some nice functionality. Using Magento’s 404 event handlers of cms module you can integrate 3rd Party CMS Content such Expression Engine, Drupal, wordpress, joomla etc within Magento.
Magento is robust and have some great nice features but still their documentation is very poor. In Magento forum and wiki they just demonstrate “how to override a controller?” as a general theory. But how to override exceptional cms and api controller is not clear. Even Magento did not mention anything about exceptionality of cms and api module. Cms module calls internally. So we cannot override cms module’s controller using as usual magento controller override process. Here I described how to overrite cms index and page controller.

Target : Override Cms module’s Index (Mage_Cms_IndexController) controller and Page (Mage_Cms_IndexController) controller.

Hint: IndexController is responsible for displaying errors (404) & home page and PageController is responsible for displaying pages like ‘about-us’, keep this in mind as you may want to rewrite which controller.

Ok, let’s start—

Firsty, it’s wise to name your module differently to avoid name collisions. Lets call my module M4U_Mycms for that case.

<?xml version="1.0"?>
<config>
    <modules>
        <M4U_Mycms>
            <active>true</active>
            <codePool>local</codePool>
        </M4U_Mycms>
    </modules>
</config>

Now create config xml for new module in app/code/local/M4U/Mycms/etc/config.xml. Here as example I mention xml to override norouteAction method of IndexController.

<?xml version="1.0"?>
<config>

    <modules>
        <M4U_Mycms>
            <version>0.1.0</version>
        </ M4U_Mycms>
    </modules>
   
    <frontend>
        <routers>
            <mycms>
                <use>standard</use>
                <args>
                    <module> M4U_Mycms</module>
                    <frontName>mycms</frontName>
                </args>
            </mycms>
        </routers>
</frontend>	
	
<global>
     <routers>
            <cms>
                <rewrite>
                    <index>
                        <to>M4U_Mycms/index</to>
                        <override_actions>true</override_actions>
                        <actions>
                           <noroute><to> M4U_Mycms/index/noroute</to></noroute>
                        </actions>
                    </index>
                </rewrite>
            </cms>
        </routers>

       </global>
</config>

N.B: Please take care about tag. It will let you create additional NEW actions that will be rewritten to new controller.

Now create new index controller in app/code/local/M4U/Mycms/controllers/IndexController.php and update noRouteAction method.

require_once "Mage/Cms/controllers/IndexController.php";
class M4U_Mycms_IndexController extends Mage_Cms_IndexController
{
    public function noRouteAction($coreRoute = null)
    {
        //modify this method as you need
        
        exit('Yes, I can successfully override cms/index noRoute method ');
		
        //$this->getResponse()->setHeader('HTTP/1.1','404 Not Found');
        //$this->getResponse()->setHeader('Status','404 File not found');
       // $pageId = Mage::getStoreConfig('web/default/cms_no_route');
       // if (!Mage::helper('cms/page')->renderPage($this, $pageId)) {
       //     $this->_forward('defaultNoRoute');
       // }
    }
}

Done !!

When any requested class/method is not found in system then Magento throw “404 Not Found” error using noRouteAction method. So we can test this method calling any undefined page url like http://127.0.0.1/magento/index.php/undefinedpagename. Here, undefinedpagename is not a defined page in magento.

ok, now run http://127.0.0.1/magento/index.php/undefinedpagename and if you get result
“Yes, I can successfully override cms/index noRoute method” in browser then noRouteAction method override is success.

Here i just describe noRouteAction method modification system. Like this way you can modify all of the indexController and pageController method.

You will get source code in right side box widget. Download code and enjoy your work.

if need any help let me know.

Today at 11.00AM, i entered in office and check mail. Than started my schedule work. I open a file and just wrote 2 lines code

print_r($this->getOrders());

and hit the browser url. Oh my god !! browser is loading and loading data. After 10 minutes i see browser is hanged !! Then i closed the browser. Again start browser and run the same url but no luck got the same result.

Now what can i do ? then i update code like this

 $orders = Mage::getResourceModel('sales/order_collection')
            //->addAttributeToSelect('*')
            ->joinAttribute('shipping_firstname', 'order_address/firstname', 'shipping_address_id', null, 'left')
            ->joinAttribute('shipping_lastname', 'order_address/lastname', 'shipping_address_id', null, 'left')
            ->addAttributeToFilter('customer_id', Mage::getSingleton('customer/session')->getCustomer()->getId())
            ->addAttributeToFilter('state', array('in' => Mage::getSingleton('sales/order_config')->getVisibleOnFrontStates()))
            ->addAttributeToSort('created_at', 'desc')
        ;

        $this->setOrders($orders);
        print_r($this->getOrders());

wowwwwww… now i got the data after 2 minutes !!

Here i see magento loaded around 10 thousands line data just to show a single order of a customer.

Then i again run below modified code

 $orders = Mage::getResourceModel('sales/order_collection')
            ->addAttributeToSelect('*')
            //->joinAttribute('shipping_firstname', 'order_address/firstname', 'shipping_address_id', null, 'left')
            //->joinAttribute('shipping_lastname', 'order_address/lastname', 'shipping_address_id', null, 'left')
            ->addAttributeToFilter('customer_id', Mage::getSingleton('customer/session')->getCustomer()->getId())
            //->addAttributeToFilter('state', array('in' => Mage::getSingleton('sales/order_config')->getVisibleOnFrontStates()))
            //->addAttributeToSort('created_at', 'desc')
        ;

        $this->setOrders($orders);
        print_r($this->getOrders());

Now i got result and copy that data from browser and paste in MS word file. To keep all data MS word take 2499 !! pages and file size is 12.8 MB !!

You believe it or not , i have just discovered the largest array of the world !!
If any guys know about larger array then you can challenge me. I am ready for your bouncer.

Download Doc

Objectives: I will create a new page in Magento whose output will be “Hello World ! I am a Magento Guy..”.

Target: Create a new module called “HelloWorld”

Step 1: Module Declaration

Create app/etc/modules/M4U_HelloWorld.xml and write below code

<?xml version="1.0"?>
<config>
         <modules>
                <M4U_HelloWorld>
                        <active>true</active>
                        <codePool>local</codePool>
                </M4U_HelloWorld>
         </modules>
</config>

Step 2: Module Configuration

a. Create a controller class app/code/local/M4U/HelloWorld/controllers/IndexController.php

class M4U_HelloWorld_IndexController extends Mage_Core_Controller_Front_Action
{
    public function indexAction()
    {
     $this->loadLayout(array('default'));
     $this->renderLayout();
    }
}

b. Create a Block class app/code/local/M4U/HelloWorld/Block/HelloWorld.php

class M4U_HelloWorld_Block_HelloWorld extends Mage_Core_Block_Template
{
  // necessary methods
}

c. create configuration xml in app/code/local/M4U/HelloWorld/etc/config.xml

<?xml version="1.0"?>
<config>
	<global>
		<modules>
                <m4u_helloworld>
                        <version>0.1.0</version>
                </m4u_helloworld>
        </modules>
	<blocks>
            <helloworld>
                <rewrite>
		 <helloworld>M4U_HelloWorld_Block_HelloWorld</helloworld>
		</rewrite>
            </helloworld>
	 </blocks>

        </global>
	   <frontend>
                <routers>
                        <helloworld>
                                <use>standard</use>
                                <args>
                                      <module>M4U_HelloWorld</module>
                                      <frontName>helloworld</frontName>
                                </args>
                        </helloworld>
                </routers>
		<layout>
			<updates>
				<helloworld>
		   		      <file>helloworld.xml</file>
				</helloworld>
			</updates>
       		</layout>
        </frontend>
</config>

Define Frontend Template :

1. Define page layout in app/design/frontend/M4U/default/layout/helloworld.xml

N.B: Use default instead of M4U as template location if you use default design packages. Means create file in app/design/frontend/default/default/layout/helloworld.xml

<?xml version="1.0"?>

	<layout version="0.1.0">

		<helloworld_index_index>
			<reference name="root">
				<action method="setTemplate"><template>page/1column.phtml</template></action>
       	 	</reference>
			<reference name="content">
            	<block type="helloworld/helloworld" name="hello" template="helloworld/helloworld.phtml"/>
        	</reference>
		</helloworld_index_index>

	</layout>

2. Create template file app/design/frontend/M4U/default/template/helloworld/helloworld.phtml and write down

N.B: Use default instead of M4U as template location if you use default design packages. Means create file in app/design/frontend/default/default/template/helloworld/helloworld.phtml

Hello World ! I am a Magento Guy..

Hey, new module is ready to run and hit browser with url http://127.0.0.1/projectname/index.php/helloworld/

and see result.

That’s it……..

Is it easy or not ? what you think ?

Coder, Please at first try yourself.

Ohh.., Still are you facing problem ? Lets download full module source code from left panel “BOX” section or let me know.

Note: I have upgraded HelloWorld module source code of BOX widget. So it will resolve the problem which was faced by some guys.

Let’s create a module :

Module Declaration:
Create app/etc/modules/M4U_NewModule.xml and write below code

<?xml version="1.0"?>
<config>
         <modules>
<!-- declare CompanyName_NewModule module -->
           <M4U_NewModule>
<!-- this is an active module -->
                  <active>true</active>
<!-- this module will be located in app/code/local code pool -->
                  <codePool>local</codePool>
<!-- specify dependencies for correct module loading order -->
                  <depends>
                             <Mage_ExistingModule />
                  </depends>
<!-- declare module's version information for database updates -->
                  <version>0.1.0</version>
           </M4U_NewModule>
	</modules>
</config>

Here is example of create new M4U_customer module to override existing Mage_Customer module and M4U_Credit module to create new credit module.

<config>
    <modules>
        <M4U_Customer>
           <active>true</active>
           <codePool>local</codePool>
        </M4U_Customer>
        <M4U_Credit>
           <active>true</active>
           <codePool>local</codePool>
        </M4U_Credit>
    </modules>
</config>

Our new module will be called NewModule.

Replace all instances of ‘NewModule’ with name of your module and ‘newmodule’ with simplified code, that contains only alphanumeric characters and underscore.

To make this tutorial most concise, it’s implied that mentioned folders will be created when needed.

Module Configuration:

Create Model, Helper, coltrollers, Block, sql and etc folder under  app/code/local/M4U/NewModule/ and configure app/code/local/M4U/NewModule/etc/config.xml like below:

<?xml version="1.0"?>
   <config>
       <modules>
           <M4U_NewModule>
                 <version>0.1.0</version>
           </M4U_NewModule>
       </modules>

<!-- define Front end controller and template  -->
       <frontend>
<!-- define Front end controller  -->
           <routers>
               <newmodule>
                   <use>standard</use>
                   <args>
                          <module>M4U_NewModule</module>
                          <frontName>newmodule</frontName>
                   </args>
               </newmodule>
           </routers>
<!-- define Front end template xml -->
           <layout>
               <updates>
                    <newmodule>
                         <file>newmodule.xml</file>
                    </newmodule>
                </updates>
              </layout>
           </frontend>   

<!-- define blocks, models, helpers in global area -->
            <global>
               <models>
                  <newmodule>
                         <class>M4U_NewModule_Model</class>
                  </newmodule>
               </models>
               <blocks>
                  <newmodule>
                          <class>M4U_NewModule_Block</class>
                  </newmodule>
               </blocks>
               <helpers>
                  <newmodule>
                          <class>M4U_NewModule_Helper</class>
                  </newmodule>
               </helpers>

<!-- declare resource setup for new module -->
               <resources>
                    <newmodule_setup>
<!-- specify that this resource is a setup resource and used for upgrades -->
                       <setup>
<!-- which module to look for install/upgrade files in -->
                           <module>M4U_NewModule</module>
                       </setup>
<!-- specify database connection for this resource -->
                       <connection>
<!-- do not create new connection, use predefined core setup connection -->
                           <use>core_setup</use>
                       </connection>
                    </newmodule_setup>
                    <newmodule_write>
                         <connection>
                              <use>core_write</use>
                         </connection>
                    </newmodule_write>
                    <newmodule_read>
                         <connection>
                               <use>core_read</use>
                         </connection>
                    </newmodule_read>
                </resources>
           </global>
      </config>

Adapter Class:
To obtain module functionality you can write necessary method in various classes as magento convention.
1. Create necessary model class in app/code/local/M4U/NewModule/Model/
2. Create Block in app/code/local/M4U/NewModule/Block/
3. Create Helper in app/code/local/M4U/NewModule/Helper/
4. Place necessary updated database sql file in app/code/local/M4U/NewModule/sql/

Frontend Template Define:

1. Define page layout in app/design/frontend/M4U/default/layout/NewModule.xml

<?xml version="1.0"?>
   <layout version="0.1.0">
     <newmodule_index_usercredit>
        <reference name="root">
            <action method="setTemplate"><template>page/1column.phtml</template></action>
        </reference>
        <update handle="customer_account"/>
        <reference name="content">
            <block type="newmodule/blockClassName" name="usercredit" template="newmodule/usercredit.phtml"/>
        </reference>
     </newmodule_index_usercredit>
</layout>

2. Create template file app/design/frontend/M4U/default/template/newmodule/usercredit.phtml

Troubleshooting

• Dont put your module in /Mage. It belongs in app/code/community/ or app/code/local/
• Make sure your module’s first letter is capitlized. newmodule apparently will not work, it must start with a capital letter Newmodule.
• If your module is not showing in configuration>advanced then check your config.xml
• Make sure you clear the cache.

In this post i described general module customization theory of Magento. For more clarification you can see next post  “write HelloWord module” in this blog.