The document provides information on how to write custom modules for PHP-based e-commerce systems like Magento, OXID eShop, and Shopware. It discusses the structure and templating systems of these platforms, how to extend core classes through inheritance, and build plugins to add new functionality like displaying the number of days until Christmas on product pages. The document drills down through the different layers from templates to models to explain how to access data from a module.

1. How
to
write
Custom
Modules
for
PHP-­based
E-­
Commerce
Systems
Roman
Z.

2. Roman
Zenner
• Working
as
freelance
trainer,
author
and
consultant
since
2004
• Has
written
three
books
on
Magento
and
OXID
eShop
• Is
in
the
process
of
writing
a
“cookbook”
on
OXID
eShop
with
Joscha
Krug
• Publishes
in
various
magazines

3. Initial
thoughts
• Modularity
a
no-­‐brainer
in
today’s
ecommerce
software
• There
must
be
a
way
of
extending
classes
or
an
event-­‐listener
system
in
order
to
integrate
custom
functionalities

4. Types
of
modules
• Encapsulate
graphical
(template)
changes
• Provide
additional
information
(e.g.
for
an
article
• Special
calculations
• Payment
and
shipping
• Other
interfaces
(ImpEx,
etc.)

5. Today‘s
candidates
• Magento
• OXID
eShop
• Shopware

6. http://www.flickr.com/photos/exey/3815327201

8. Brief
History
• First
stable
version
released
in
spring
2008
• Community
Edition
under
OSL
• Professional
and
Enterprise
Editions
• Based
on
Zend
Framework
and
MySQL
• Relies
heavily
on
EAV
structure
• XML
de^initions
• Bought
by
eBay
in
2011
(X.commerce)
• Current
stable
version:
1.7.0.2

9. Structure

10. Templates
(1)

11. Templates
(2)

12. Templates
(2)
<block type="page/html“ name="root" output="toHtml“ template="page/3columns.phtml">
<block type="page/html_header" name="header" as="header">
<block type="page/switch" name="store_language" as="store_language"
template="page/switch/languages.phtml"/></block>
</block>
Template: /layout/page.xml
<?php if(count($this->getStores())>1): ?>
<div class="form-language“>
<?php foreach ($this->getStores() as $_lang): ?>
<?php $_selected = ($_lang->getId() == $this->getCurrentStoreId())
? ' selected="selected"' : '' ?>
<option value="<?php echo $_lang->getCurrentUrl() ?>"<?php echo $_selected ?>>
<?php endforeach; ?>
</div>
<?php endif; ?>
Template: /template/page/switch/languages.phtml

13. Drilling
down
(1)
Example:
How to get from the article name in
the template to the database field?

14. Drilling
down
(2)
1. Block: <block type="catalog/product_view" name="product.info" template="catalog/
product/view.phtml">
2. Template: /app/design/frontend/base/default/template/catalog/product/view.phtml
3. Block class: Mage_Catalog_Block_Product_View
4. Model: Mage_Catalog_Model_Product:
public function getProduct()
{
if (!Mage::registry('product') && $this->getProductId()) {
$product = Mage::getModel('catalog/product')->load($this->getProductId());
Mage::register('product', $product);
}
return Mage::registry('product');
}

15. Drilling
down
(3)
1. Abstract class: Mage_Core_Model_Abstract
2. Resource model: Mage_Core_Model_Mysql4_Abstract
public function load($id, $field=null)
{
$this->_beforeLoad($id, $field);
$this->_getResource()->load($this, $id, $field);
$this->_afterLoad();
$this->setOrigData();
$this->_hasDataChanges = false;
return $this;
}

16. Modules

18. Brief
History
• OS-­‐Edition
since
late
2008.
• Based
on
own
PHP-­‐Framework
&
MySQL
• Recent
version:
4.7.3

19. Features
• ADODB
database
abstraction
layer
• Uses
Smarty
2
(but
Template
Inheritance
by
Smarty
3)
• Block
Inheritance
• Autoloader

20. Structure

21. Template
Inheritance
(1)

22. Template
Inheritance
(2)
[{capture append="oxidBlock_content"}]
[{assign var="oFirstArticle" value=$oView->getFirstArticle()}]
[{/capture}]
[{include file="layout/page.tpl" sidebar="Right"}]
/out/azure/tpl/page/shop/start.tpl

23. Template
Inheritance
(3)
<div id="content">
[{include file="message/errors.tpl"}]
[{foreach from=$oxidBlock_content item="_block"}]
[{$_block}]
[{/foreach}]
</div>
[{include file="layout/footer.tpl"}]
/out/azure/tpl/layout/page.tpl

24. Drilling
down
(1)
Example:
How
to
get
from
the
article
name
in
the
Smarty-­‐Template
to
the
database
^ield?

25. Drilling
down
(2)
• Article
detail
page:
/out/azure/tpl/page/details/inc/productmain.tpl
[{block name="details_productmain_title"}]
<h1 id="productTitle"><span itemprop="name">
[{$oDetailsProduct->oxarticles__oxtitle->value}]
[{$oDetailsProduct->oxarticles__oxvarselect->value}]</span></h1>
[{/block}]
Scheme: [Object name]->[Table name]__[Field name]->value
• View controller: /application/controller/details.php

26. Drilling
down
(3)
public function render()
{
$myConfig = $this->getConfig();
$oProduct = $this->getProduct();
}
public function getProduct()
{
$sOxid = oxConfig::getParameter( 'anid' );
$this->_oProduct = oxNew( 'oxarticle' );
if ( !$this->_oProduct->load( $sOxid ) ) {
...
}
}

27. Drilling
down
(4)
public function load( $oxID)
{
$blRet = parent::load( $oxID);
public function load( $sOXID)
{
//getting at least one field before lazy loading the object
$this->_addField('oxid', 0);
$sSelect = $this->buildSelectString( array( $this->getViewName().".oxid" => $sOXID));
return $this->_isLoaded = $this->assignRecord( $sSelect );
}
/application/models/oxarticle.php
/core/oxbase.php

28. Custom
classes
(1)
• Most
view-­‐
and
core
classes
can
be
overloaded
• Module
are
registered
in
backend
• Object
instantiation
via
oxNew():
core/oxutilsobject.php
oxArticle
my_oxArticle
our_oxArticle
class my_oxArticle extends oxArticle
class our_oxArticle extends my_oxArticle

29. Custom
classes
(2)
• This
procedure
becomes
problematic
when
there
is
more
than
one
new
module
wanting
to
extend
a
speci^ic
class.
• Solution:
oxNew()
dynamically
creates
transparent
classes
in
the
form
of:
[class-­name]_parent
• This
means
that
by
means
of
the
following
structure,
module
classes
can
be
chained:
– oxArticle
=>
my_oxArticle&our_oxArticle

30. Plugins
(1)
• Task:
Write
a
module
that
displays
the
remaining
time
until
X
mas
with
each
article.
1. New
module
directory:
/modules/xmas/
2. Publishing
it
via
metadata.php
(used
to
be
via
Admin)
'extend' => array(
'oxarticle' => ‘xmas/xmasArticle'
)

31. Plugins
(2)
class
xmasArticle
extends
xmasArticle_parent
{
public
function
getDaysLeft()
{
$time
=
mktime(0,
0,
0,
12,
25,
2011,
1)
-­‐
time();
$days
=
^loor($time/86400);
return
$days;
}
}
<div>Only [{$oDetailsProduct->getDaysLeft()}] days left until Xmas!</div>
/modules/xmas/xmasArticle.php
/out/azure/tpl/page/details/inc/productmain.tpl

33. Brief
History
• First
stable
version
released
in
2007.
• OS-­‐Edition
since
October
2010.
• Since
v.3.5
based
on
Enlight
Framework
(based
on
ZF)
&
MySQL
• MVC-­‐Model
• Backend
based
on
ExtJS
4
• Templates
based
on
Smarty
3
• Recent
version:
4.0.7

34. Enlight-­‐Framework
• Basis
functionalities
are
inherited
from
Zend
Framework:
• Syntax
and
Work^low
• Request-­‐
and
Response-­‐Objects
• Action-­‐Controller
Design
• Rewritten
Router
/
Dispatcher
and
View-­‐
Object
optimised
for
performance
and
expandability
• Own
plugin
system
based
on
events
and
hooks

35. Template-­‐Structure

36. index.tpl
{* Content section *}
<div id="content">
<div class="inner”>
{* Content top container *}
{block name="frontend_index_content_top"}{/block}
{* Sidebar left *}
{block name='frontend_index_content_left'}
{include file='frontend/index/left.tpl'}
{/block}
{* Main content *}
{block name='frontend_index_content'}{/block}
{* Sidebar right *}
{block name='frontend_index_content_right'}{/block}
<div class="clear">&nbsp;</div>
</div>
</div>

37. Template-­‐Inheritance
{extends file=”../_default/frontend/home/index.tpl}
{block name=’frontend_index_content’ prepend}
<h1>Hallo Welt</h1>
{/block}
SMARTY:
Append – Prepend - Replace

38. Plugin-­‐Directory
Structure

39. Drilling
down
Example:
How
to
get
from
the
article
name
in
the
Smarty-­‐Template
to
the
database
^ield?

40. Drilling
down
(2)
• Article
detail
page:
templates_defaultfrontenddetailindex.tpl
• Part
that
displays
article
name
in
frontend
• Template-­‐Path
(frontend/detail/index.tpl)
tells
us
where
to
^ind
the
corresponding
controller.
In
this
case:
Shopware/Controllers/
Frontend/Detail.php
–
indexAction.
• Get
article
information
from
Model
and
assign
to
template
• Shopware()-­>Modules()-­>Articles()
is
a
service
locator
to
access
the
main
article
object
that
could
be
found
at
/engine/core/class/
sArticles.php
• sGetArticleById
fetches
a
certain
article
by
id
from
database
and
returns
the
result
as
an
array
for
further
processing

41. Plugins:
Bootstrap
<?php
class Shopware_Plugins_Frontend_IPCDEMO_Bootstrap
extends Shopware_Components_Plugin_Bootstrap
{
public function install()
{
//
return true;
}
public static function onPostDispatch(Enlight_Event_EventArgs $args)
{
// Still empty
}
}

42. Plugins:
Event
public function install()
{
$event = $this->createEvent('Enlight_Controller_Action_PostDispatch','onPostDispatch');
$this-> subscribeEvent($event);
$form = $this->Form();
$form->setElement('textarea', ’yourtext',
array('label'=>’Text for left column’,'value'=>’Hello World'));
$form->save();
return true;
}

43. Plugins:
Listener
!public static function onPostDispatch(Enlight_Event_EventArgs $args)
{
$view = $args->getSubject()->View();
$config = Shopware()->Plugins()->Frontend()->IPCDEMO()->Config();
$view->pluginText = $config->yourtext;
$view->addTemplateDir(dirname(__FILE__)."/Views/");
$view->extendsTemplate('plugin.tpl');
}

44. Plugins:
Hooks
<?php
class Shopware_Plugins_Frontend_myHook_Bootstrap extends Shopware_Components_Plugin_Bootstrap
{
public function install()
{
$hook = $this->createHook(
'sArticles',
'sGetArticleById',
'onArticle',
Enlight_Hook_HookHandler::TypeAfter,
0
);
$this->subscribeHook($hook);
return true;
}
static function onArticle(Enlight_Hook_HookArgs $args)
{
}
}

45. Summary
•
Each
system
employs
a
slightly
different
method
of
inserting
custom
functionalities
•
Layout
and
functional
^iles
are
more
or
less
encapsulated
•
No
core-­‐hacking
required
–
still
a
need
for
testing!

46. Thank
you!
Blog:
romanzenner.com
Skype:
roman_zenner
XING:
xing.com/pro^ile/Roman_Zenner
Twitter:
twitter.com/rzenner

47. MVC-­‐Model
(extended)