Here are the slides of Jahia's Developers Meetup held in Paris on January 25, 2017. The topic of this meetup was: External Data Provider an Headless Way to Share Content. You can watch the replay here : https://www.youtube.com/watch?v=mkLzkEiz5WQ

1. 1
DX External Data Provider in an headless world
January 25th, 2017

2. 2
Introduction
What will you see?
External data provider
Rendering capabilities of DX
Learn how to bake a cake
There are 28 slides and 3 bonus

3. 3
The basics: get content,
display it.
1

4. 4
1
Simple use case
Goal to achieve:
- Give the world access to my catalog
Requirements:
- A Catalog
- A web server application (the world)

5. 5
1
Things to do
- Expose the catalog to the world
- Create a connector in the web server application to read the
Catalog
2 connectors :
- ExposeCatalog
- DisplayCatalog

6. 6
Now, complicate things a bit
2

7. 7
2 Add a new source of content
Goal to achieve:
- Provide content from a completely different Catalog
Things to do:
- Create a connector to this catalog
- Edit the display connector to fit the new structure

8. 8
2 Add a new output
Goal to achieve:
- Expose the content to an Android / iOS / raspberry application
Things to do:
- Edit the 2 connectors to support this new output
- Create a new output connector to support all the external
sources with their input connectors

9. 9
2

10. 10
2 And life goes on ...
New outputs to add
New sources to add
Time needed increase dramatically
Complex to maintain

11. 11
2 DX
Use DX as a solution between your content sources and the outside
world
Using the External Data Provider to get the Data
Using the rendering mechanism and structure to deliver it
- Quick development
- Easy to maintain
- Easy to evolve

12. 12
2

13. 13
3
Your content in DX:
External Data Providers

14. 14
What is an External Data Provider ?
Functionally: A way to virtualize content in
DX JCR tree
Technically: A simple DX module
3

15. 15
How to create an External Data
Provider
Set an external provider declaration based on
org.jahia.modules.external.ExternalContentStoreProvider
Define an External Data Source implementing
org.jahia.modules.external.ExternalDataSource
Create an External Data object
3

16. 16
ExternalContentStoreProvider
Use spring to instantiate the provider.
<bean id="ExternalGenericDatabaseProvider" class="org.jahia.modules.external.ExternalContentStoreProvider"
parent="AbstractJCRStoreProvider">
<property name="key" value="ExternalGenericDatabaseProvider"/>
<property name="mountPoint" value="/external-database-generic"/>
<property name="externalProviderInitializerService" ref="ExternalProviderInitializerService"/>
<property name="dataSource">
<bean class="org.jahia.modules.external.test.db.GenericDatabaseDataSource"/>
</property>
</bean>
The provider declaration can define provider capabilities such as:
- Extension support
- Lock support
3

17. 17
External Data Source
Implement ExternalDataSource to build ExternalData
List<String> getChildren(String path)
ExternalData getItemByIdentifier(String identifier)
ExternalData getItemByPath(String path)
getSupportedNodeTypes()
isSupportsHierarchicalIdentifiers()
isSupportsUuid()
itemExists(String path)
3

18. 18
3
External Data Object
To build it, use the default Constructor
ExternalData(String id, String path, String type, Map<String, String[]> properties, boolean isNew)

19. 19
3
Extend an External Data Source
The External Data source can be extended implementing the
following interfaces:
AccessControllable
SupportPrivileges
Searchable
Writable
CanCheckAvailability
CanLoadChildrenInBatch
Initializable
LazyProperty
Referenceable

20. 20
3
Extension
With extensions, it is possible to enhance the external content with
custom properties.
This can be useful to add ratings, comments
The content is stored in a dedicated place in the JCR.

21. 21
3
Server settings
An External Data Provider is used to mount external content into
DX.
We provide a UI in the server settings to manage mount points
No documentation yet :'(

22. 22
3
Usages
In DX:
- VFS to mount file system
- Sources in the Studio
- User and Group Provider
From modules (available on the store or in Github):
- CMIS
- Tmdb
- Database connector
- LDAP

23. 23
4
Headless rendering

24. 24
Headless
The rendering is detached from its content.
Consume JSON
Examples :
Single page app
Mobile rendering
Create a new edit UI
4

25. 25
4
DX and Headless
DX natively offers to render content in an unitary way
DX can generate JSON

26. 26
4
How to query and get JSON
Querying content can let you read the content, but also modifying it
- With the render chain:
Default json views that can be found in
/default/src/main/resources/nt_base/json
- Create an Action
- Use Jax-RS API (like in our JC Rest API module)
- Use GraphQL (this is the future)

27. 27
5
Conclusion

28. 28
Mix the things
Get your content in DX using the External Data
Provider
Generate JSON using DX capabilities
Enjoy !!
5

29. 29
5
One more thing ..
Now that your content is in DX you can use :
- Edit engines
- DX flows
- DX modules
- Play with it as any other DX content
- Etc ..

30. 30
Alternatively you can bake a cake
Here the recipe:
● nonstick vegetable oil spray
● 1 1/2 cups all-purpose flour
● 2 teaspoons baking powder
● 3/4 teaspoon kosher salt
● 1 cup sugar
● 1 tablespoon finely grated lemon zest
● 3/4 cup whole-milk Greek yogurt
● 1/2 cup vegetable oil
● 2 large eggs
● 1/2 teaspoon vanilla extract
5

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Preparation
Preheat oven to 350°F. Coat a standard (8 1/2x4 1/4") loaf pan with nonstick vegetable oil spray.
Dust with flour; tap out excess. Whisk 1 1/2 cups all-purpose flour, 2 teaspoons baking powder, and 3/4 teaspoon kosher
salt in a medium bowl.
Using your fingers, rub 1 cup sugar with 1 tablespoon finely grated lemon zest in a large bowl until sugar is moist.
Add 3/4 cup whole-milk Greek yogurt, 1/2 cup vegetable oil, 2 large eggs, and 1/2 teaspoon vanilla extract; whisk to blend.
Fold in dry ingredients just to blend.
Pour batter into prepared pan; smooth top.
Bake until top of cake is golden brown and a tester inserted into center comes out clean, 50-55 minutes.
Let cake cool in pan on a wire rack for 15 minutes. Invert onto rack; let cool completely. DO AHEAD: Can be made 3 days
ahead. Store airtight at room temperature.
5

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THE END!
THANKS FOR LISTENING