Hi everyone,

I’m Stephen. Today I will continue the Topic 1: Basic with the next part- Magento Module-based architecture.

Magento is built based on module architecture. All activities of Magento are processed by modules.

In this post we will talk about:

1. Describe module architecture

2. List steps to add a new module

3. Describe module limitations

4. Sample questions & answers

I - Describe module architecture

A built module of Magento may work following the structure: MVC (model – view –control) with functions of each are below:

MVC in Magento: http://www.magentocommerce.com/wiki/_media/general/doc/page-request-flow.png

Besides, module in magento may be built based on EDA architecture to send and catch events in the system (EDA architecture has been mentioned in part 1- Fundamentals).
II - List steps to add a new module

To add a new module in Magento, we need at least 2 following steps:

Step 1: Register module with the system by naming file configure (e.g. file Magestore_Test.xml into the folder /app/etc/modules/. File Magestore_Test.xml with the content like this:

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

Step 2: Create code in folder /app/code/local/Magestore/Test. Files needed for module will be shown in the next parts.

III - Describe module limitations

Limitations of modules:

IV – Questions

1. Q: When the system runs, does it load all files in module? If not, why when creating a new object or extend class from a class without including class’s source file, the system does not show errors?

A: When running Magento, the system will just load files including the class which we called.

Magento uses a magic function spl_autoload_register(‘name_function_autoload’); of PHP. When you create a new object or extend class from a class that doesn’t exist, the function name_function_autoload will automatically run before adding new or extending from a class.

The function name_function_autoload has parameter named class, so it’s the type function name_function_autoload(class). In Magento, from the name of a class, the system can immediately find the path and files including that class (due to rules of naming in Magento).

Is this post useful to you? Hope so I will be pleased to answer or discuss any questions with you guys.