This session will provide an overview of the different technics available to developers to create advanced modules, the extension points and explain when it is preferable to use one approach or another depending on the scenario.

1. Advanced module
development
Choose the right strategy
Thomas Draier
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2. Define your content
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3. Define your content




Definitions
Initializers ( for default values / autocreated )
ChoiceListInitializers
Define constraints
 Mandatory property / subnode
 Regular expressions
 Validators
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4. How to render content to users
Display your content
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5. Display your content
 Jahia rendering system
 Use render service for every node
 Render chain ends up with view call
 Views : one folder per component type
 A module can override exisiting views
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6. Display your content
 Simple JSPs
 Simple to use
 Can use all jahia taglibs / JSTL
 Include your own taglib for complex code
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7. Display your content
 Groovy scripts
 Better for complex code with method
declaration, recursions, …
 Limited rendering
 Cannot use any taglib, but access to Jahia
/JCR API
 Example : navigation menu
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8. Display your content
 Webflow
 MVC model
 Can call controller class to prepare view
 Use JSPs for views
 Allows user interaction
 Example : administration components
Using Spring Web Flow - Friday, 02:00 PM
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9. Display your content
 Spring controller
 Same as a servlet
 Can return any content type
 No mapping with nodes, need to define your
own parameters
 Can be declared in a module
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10. Different ways to let the user modify the content
Create and update
content
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11. Create and update content
 REST API
 Create a single node, update properties
 Can be used in AJAX or simple HTML forms
 Can redirect to a jahia page, or return Json
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12. Create and update content
 Json REST API
 Create nodes, update properties, full Json
 More powerful
 HATEOAS, Use HAL style links
 Can be used only in AJAX
Jahia 7 new Rest API, 11:45 AM
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13. Create and update content
 Actions
 Custom code, can use all Jahia / JCR API
 Can be used in AJAX or simple forms
 Can redirect to a jahia page
 Can return info to the user only in AJAX
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14. Create and update content
 Webflow
 Custom code, can use all Jahia / JCR API
 Stateful
 Cannot be used with AJAX calls
Using Spring Web Flow - Friday, 02:00 PM
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15. How to listen to content modifications
React to events
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16. React to events
 Rules
 Easy to create and modify
 Many simple conditions/consequences available - look
at existing DSL files
 Module can register reusable custom services and
DSL
 Rule can start background jobs, workflows, …
 Rule can replace action, when combined with Rest API
 Cluster : triggered only on the server which created the
event
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17. React to events
 Listeners
 Direct access to all JCR events (node or
properties added/removed/updated)
 Easier to debug
 Can have a performance impact
 Cluster : can listen to event on other servers
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18. How to transform your content after rendering
Post process your content
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19. Post process your content
 Macros
 Simple groovy scripts
 Can be called on whole page :
WEB-INF/macros
##username## , ##requestParameters##
 or per module :
WEB-INF/modules-macros
##authorName## , ##creationdate##
 Page level macros are not cached !
 Available in edit engine for editors
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20. Post process your content
 Render Filter
 Used to prepare and/or alter the rendering
 Can be placed anywhere in the render chain
- need to specify a correct priority !
 Use different scopes : whole page or module
 Example : set up connection with external
system, transform content after rendering …
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21. Post process your content
 Errors JSPs or Error Handlers
 Use JSPs error only to display message
 Use error handler to catch exceptions and
handle some processing
 Example : Wiki redirects 404 to creation form
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22. Always check how your content is cached in live …
Cache management
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23. Cache management
 Use expiration settings carefully
 Default expiration set to 4h
 Reduce expiration time for content which can
change with time
 Never set expiration=0 for content with heavy
processing ( queries, … ), customize cache
key or use AJAX calls instead !
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24. Cache management
 Cache key
 Cache fragment = HTML rendering of a
component, without its submodules
 Each fragment has a key
 Key is composed of multiple parts : node
path, view used, language, acls, request
parameters, context site, …
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25. Cache management
 ACL Cache key
 Users with different roles on the node see
different things - different fragments
generated by default
 Customizable implementation
 Correctly set with cache.dependsOnVisibilityOf
property
 Example : jnt:contentList
cache.dependsOnVisibilityOf=$currentNode/[^/]*
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26. Cache management
 Cache Key customization
 Define parameters that are known to alter
the rendering
 Test the node type before adding things in
the key
 Beware of number of dimensions - cache
size can grow quickly !
 Example : add user segment to the key
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27. Reuse the frameworks and services provided by Jahia
Use shared services
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28. Use shared services
 Workflows : define processes which imply user
interaction
 JBPM 6 / BPMN 2
 Create workflows for any type of operation
 Start workflow with actions
 User tasks appear in dashboard
 Define workflow participant through the roles
 Create custom work handlers
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29. Use shared services
 Social module : activity feed
 Create an activity type
[jnt:socialActivity] > jnt:baseSocialActivity
 Set up a rule to trigger activities creation
Add activity of type {activityType} on {node}
with parameters {params}
 Define a recorder that will populate activity
nodes
void recordActivity(…)
 Create views for your activities
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30. Use shared services
 Atmosphere
 Develop asynchronous web application
 Push / broadcast content to users
Extending Jahia with NoSQL - Thursday, 04:45 PM
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31. Use shared services
 CAMEL
 Can send or receive events through different
channels
 Configure routes in Gateway service
 Can receive mail using decoders
 Supports Enterprise Integration Pattern
 Example : Wise mail integration
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32. Use shared services
 Spring Data
Extending Jahia with NoSQL - Thursday, 04:45 PM
 External providers
External Data Provider - Friday, 09:45 AM
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33. Questions
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