Tips for Twits

Magento code is awesome. So awesome that 20 wiki entries and a 100 files open later i’m was still lost. So much that i ordered the PHP|architects Magento book! At first i was disappointed in its coverage but it did help me out along the way. So heres a synthesized description of our efforts. We’re breaking up this HOWTO into a few segments into increasing orders of complexity and integration.

Note: Apparently i’ve been giving our dear readers the misconception that the book is what taught me all these techniques. WRONG. The book’s lack of coverage is what prompted me to write this. I’m not sure i was any better off reading the book!

If you have a really good idea of what you’re doing/not doing, you could cut right through the chase and download the entire tutorial’s code here: Magento Tutorial …

Otherwise, let us begin …

Do us all a favour and get your cache management right (disabled) from the beginning
Go to your system backend: http://127.0.0.1/magento/index.php/admin
Login and click ok System > Cache Management
Then on the All Cache dropdown menu, select Disable
Save cache settings

Create barebones code, file structure and config
We’re trying to achieve a proof of concept here to describe how the file structure, namespaces and config files interplay to achieve a Hello world message

1. Create your directory structure! Our NEW company name is Savant Degrees! and our module shall be called….. Twit (for a lack of an imagination). The whole module (well, almost) should rest in the /app/code/local> folder. So lets first create the following folder structure. For a hello world module, you only need a config file, a controller and a block. Ergo…

   app/
     etc/
       modules/
         - SavantDegrees_All.xml (Or what ever your company name might be)
     code/
       local/
         SavantDegrees/ (Or what ever your company name might be)
           Twit/ (Or whatever your module name might be)
             Block/
               - Index.php
             controllers/
               - IndexController.php
             etc/
               - config.xml

2. Create your config.xml file. Thats the crux of the whole module.

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   <?xml version="1.0"?> <config> <modules> <SavantDegrees_Twit> <version>0.1.0</version> </SavantDegrees_Twit> </modules> <global> <blocks> <twit> <class>SavantDegrees_Twit_Block</class> </twit> </blocks> </global> <frontend> <routers> <SavantDegrees_Twit> <use>standard</use> <args> <module>SavantDegrees_Twit</module> <frontName>twit</frontName> </args> </SavantDegrees_Twit> </routers> </frontend> </config>

   Let me explain this step a little…

   The modules > [module] > version number allows Magento to track when your module is upgraded. We’ll be seeing a version of that shortly.
   The global > blocks > [module] define the Block resources that are available under your package. We’ll be using this to generate a Hello world shortly
   The frontend > routers fragment define how the module can be access. The current code allows the block to be access via https://127.0.0.1/magento/index.php/twit

3. Create your IndexController.php file. Its as simple as:

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   <?php class SavantDegrees_Twit_IndexController extends Mage_Core_Controller_Front_Action {   public function indexAction() { $this->loadLayout(); $this->getLayout() ->getBlock('content')->append( $this->getLayout()->createBlock('twit/index') ); $this->renderLayout(); } }

   More Explanation: The twit/index refers to the index block inside the Twit module, which is defined in the config file above. We’re trying to put its contents inside the layout.

4. Lastly, we’ll create the Index.php Block:

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   <?php class SavantDegrees_Twit_Block_Index extends Mage_Core_Block_Template { protected function _toHtml() { return 'Hello world'; } }

   You DO understand SOME PHP don’t you?

5. Finally, we activate the module by creating the file SavantDegrees_All.xml file

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

6. Wake up the Magento installer by logging into the admin backend, System > Configuration > Advanced. Click on Save Config. Clear your cache at /var/cache too just to be sure.

Tada! Navigate to https://127.0.0.1/magento/index.php/twit to see your well deserved Hello World!