Prepare your extension for
Joomla 4
Allon Moritz
Joomla World Conference 19. November 2017
https://joomla.digital-peak.com
Joomla World Conference 2017
About Me
Allon Moritz
@digitpeak / @laoneo
Founder Digital Peak GmbH
Doing Joomla extensions since 2007
Joomla 4 Working group
Team Lead Media Manager
GsoC Mentor
https://joomla.digital-peak.com
Joomla World Conference 2017
Agenda
● Namespaces in PHP
● MVC Layer
● Component
○ Namespacing
○ Dispatcher
○ Form
● Modules
● Plugins
● Backwards compatibility
● Demo Weblinks migration
● Questions
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Joomla World Conference 2017
Namespaces in PHP
● Organising classes in a defined structure
● Autoloaded through the classloader, no manual include or require anymore
● Example ContentModelArticles becomes
\Joomla\Component\Content\Administrator\Model\ArticlesModel
● JLoader can handle the namespaces automatically
● We can distinguish between front end and back end classes
● Files can be found in /libraries/src
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Joomla World Conference 2017
Namespaces in PHP
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Joomla World Conference 2017
MVC Layer: Introduction
● Basically the legacy layer becomes the default MVC in Joomla 4
● “New MVC” layer will be deprecated
● FOF2 got removed from core
● Use Bootstrap 4 in the layouts
● JModelLegacy::getInstance will be deprecated, use the models directly
● MVCFactoryInterface to create model instances
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Joomla World Conference 2017
MVC Layer: Libraries
● The old classes are still working but the real files do exist in
● JControllerLegacy is now \Joomla\CMS\MVC\Controller\BaseController
● JModelLegacy is now \Joomla\CMS\MVC\Model\BaseDatabaseModel
● JViewLegacy is now \Joomla\CMS\MVC\View\AbstractView
● JTable stays is now \Joomla\CMS\Table\Table
● JPlugin is now \Joomla\CMS\Plugin\CMSPlugin
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Joomla World Conference 2017
Component: Namespacing
● A Joomla 4 component will have the
structure as in the picture
● Uppercase folders have classes
● Lowercase folders do hold the rest like
forms or template files
● Dispatcher is not namespaced
● Root classes do become a \ and front
● Controller and Model need an additional
parameter MVCFactoryInterface
● Front end namespace is
\FooVendor\Component\Bar\Site
● Back end namespace is
\FooVendor\Component\Bar\Administrator
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Joomla World Conference 2017
Component: Namespacing Todo
● Helpers are need to be done on a case
per case basis
○ ContentHelper
○ RouteHelper
○ QueryHelper
○ AssociationsHelper
● How to register the services in JHtml
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Joomla World Conference 2017
Component: Dispatcher
● Replacement single entry file content.php in root
● Get the application injected
● Dispatches the controller
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Joomla World Conference 2017
Component: Form
● Forms are in the folder forms under root in the extension on, eg.
/forms/article.xml
● Extra fields are registered with addfieldprefix attribute which adds the
namespace
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Joomla World Conference 2017
Modules
● Module file stays as single entry file
● Namespacing is done on the additional classes
● Modules namespace is \FooVendor\Module\Bar\Administrator for front end
● Modules namespace is \FooVendor\Module\Bar\Site for front end
● All core modules are namespaced
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Joomla World Conference 2017
Plugins
● Plugin file stays the same not namespaced
● When you have additional classes, they can be namespaced
● Plugin namespace is \FooVendor\Plugin\Content\Bar
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Joomla World Conference 2017
Backwards compatibility
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Joomla World Conference 2017
Backwards compatibility
● Target is that a Joomla 3 extension will run on Joomla 4
● Target is that a Joomla 4 extension will run on Joomla 3.9
● Classmapping for libraries so JForm still exists and maps to
\Joomla\CMS\Form\Form
● Changes are added not replaced to make sure the old code works
● Removed old deprecated code
● Changing to a more service oriented architecture, using interfaces
● Class overloading should be avoided
● Event system has changed completely. JEventDispatcher is removed, use
Factory::getApplication()->triggerEvent(‘’);
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Joomla World Conference 2017
Weblinks migration: Introduction
● Weblinks is a core supported Joomla extension
● Manages links
● Development happens on Github
https://github.com/joomla-extensions/weblinks
● It runs on Joomla 4 with a few modifications
https://github.com/joomla-extensions/weblinks/pull/362
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Joomla World Conference 2017
Weblinks migration: Dispatcher
● Create the dispatcher
● Namespace the WeblinksController as DisplayController
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Joomla World Conference 2017
Weblinks migration: List view
● Define the default view in the
DisplayController
● Namespace the weblinks list
controller
● Namespace the weblinks model
● Namespace the weblinks list view
● Move the weblinks template files to
the right position
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Joomla World Conference 2017
Weblinks migration: Form View
● Namespace the weblink controller
● Namespace the weblink model
● Namespace the weblink table
● Namespace the weblink view
● Move the weblink template files to
the right position
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Joomla World Conference 2017
Weblinks migration: Bootstrap 4
● The layout files do need to be adapted
● default.php and edit.php change from row-fluid to row
● default.php and edit.php change from spanX to col-md-X
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Joomla World Conference 2017
Weblinks migration: Misc
● The XML forms are moved to the root folder of the component
● The fields should be put into the folder Field
● For front end applies the same as back end
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Joomla World Conference 2017
Questions?
Slides on
https://joomla.digital-peak.com/blog/215-joomla-world-conference-2017
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Joomla World Conference 2017
Thank you and enjoy the day :-)
