The document discusses how OSGi can be used to create extensible plugins for Liferay 6.2. It provides an example of a shipping cost calculator application that uses OSGi plugins to make the core application modular. Country-specific shipping logic can be encapsulated in separate plugins so that the core application and individual country implementations can be developed and updated independently. The document explains how services, extensions, and dependencies are defined using OSGi to achieve this extensible plugin architecture.

1. Leveraging OSGi to Create
Extensible Plugins for Liferay 6.2
!
Eduardo García @epgarcia
Julio Camarero @juliocamarero
!
Core Engineers at Liferay, Inc
#LRNAS2014

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OSGi is about
modularity

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… and Liferay already
allowed for modularity

4. #LRNAS2014Portlets, hooks, themes, templates…
Hot Deployable modules (plugins)

5. #LRNAS2014Portlets, hooks, themes, templates…
Hot Deployable modules

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… but modules were not
modular!!

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OSGi brings into
Liferay 6.2
modularity of modules :)

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Microservices
Supported in the
marketplace from
this week

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Let’s see an example…
A Shipping Cost Calculator
https://github.com/epgarcia/liferay-plugins/commits/LRNAS2014.OSGI

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final price
common features
for all countries
specific features for
each country

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we could…
Develop a very complex and
laborious application that covers all
possible cases
!
Release a new version every time
any shipping cost algorithm
changes or we add new countries
Develop a simple core application
that covers only the common
features
!
Make the application extensible
with “country” modules
!
If a shipping algorithm changes,
our core application remains the
same and only that specific
extension must be changed

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OSGi makes this
possible in
Liferay 6.2

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Actually, this will be the
future of all Liferay 7
applications, so…
Welcome to the future!

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Audience Targeting is the first
Liferay app following this approach

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It’s all advantages!
Improves
maintainability
Maximizes
reusability
Simplification
of releases
(independent)
New Market
opportunities
(extensions)

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Sounds great, but I have
no idea about OSGi…
!
:_(

21. Leveraging OSGI #LRNAS2014
No worries, today we'll tell you all you need to know!
Through a practical use-case sample, you will
learn how to:
!
• Create OSGi plugins with the Liferay SDK
• Make your plugin hot-extensible
• Add OSGi extensions to your core plugin

22. Leveraging OSGI #LRNAS2014

23. Leveraging OSGI #LRNAS2014
Required Services for our app
• Extensions Registry
• Extensions (e.g. USA Shipping Cost,
Europe Shipping Cost…)

24. Leveraging OSGI #LRNAS2014
A service is composed by:
• An API (contract)
!
• Implementations (1 or more)

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ShippingExtension
interface

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ShippingExtensionUSA
@Component

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ShippingExtensionRegistry
@Reference

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ServiceTrackerUtil
is the tool to consume
OSGi services from non-
OSGi contexts

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bnd.bnd file defines
interdependencies
between modules
(most of them are auto-calculated)

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And the whole app can be modular too

31. Leveraging OSGI #LRNAS2014
For more information
• Visit the new Liferay Dev Site
!
• Don't miss:
• “Microservices: The OSGi Way”
by Miguel Pastor – Tue. 2.40pm Back Bay C
• “Extending Audience Targeting”
by Julio Camarero – Mon. 15.10 Gardner

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Thank you! :)
!
Questions?
@edupgv @juliocamarero