APACHE SLING & FRIENDS TECH MEETUPBERLIN, 22-24 SEPTEMBER 2014

What’s new in Sling Models 1.1Stefan Seifert, pro!vision GmbH

About the Speaker

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CQ5/AEM6 Developer Apache Sling Committer CTO of pro!vision GmbH

http://www.pro-vision.de

Overview

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Short Recap on Sling Models 1.0.x Injector-specific Annotations Constructor Injection New Injectors Alternate Adapter Interfaces

Sling Models Timeline

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March 2014 – Release 1.0.2 Included in AEM 6.0

June 2014 – Release 1.0.6 Custom Injector Annotations

September 2014 – Release 1.1.0

Short Recap on Sling Models 1.0.x

Resource Data in POJO

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Resource

Propertiesname = T-Shirtprice = 19.50

available = true

@Model(adaptables = Resource.class)

public class Product {

@Inject

private String name;

@Inject

private double price;

@Inject

private boolean available;

}

adapt

Product item = resource.adaptTo(Product.class);

Alternative: Interface instead of POJO

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Resource

Propertiesname = T-Shirtprice = 19.50

available = true

@Model(adaptables = Resource.class)

public interface Product {

@Inject

public String getName();

@Inject

public double getPrice();

@Inject

public boolean isAvailable();

}

adapt

Product item = resource.adaptTo(Product.class);

What can be injected (1.0.x)

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Script Variables (Sling Bindings) Value Map (Resource properties) Child Resources Request Attribute OSGi Service References

Design Goals

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Integrates nicely with adaptTo but does not require a custom AdapterFactory

POJOs and Interfaces with Annotations Name-based and class-based injections Pluggable Architecture

Learn more about the basics

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Presentation by Justin Edelsonhttp://slideshare.net/justinedelson/sling-models-overview

Injector-specific Annotations

Custom Injector Annotations (since 1.0.6)

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@Inject queries all Injector implementations “First Match” wins

Injector-specific annotationsspecify the source explicitly

One custom annotation instead of a couple of generic ones

Example: Value Map

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Generic Annotation Injector-specific Annotation

@Inject

String name;

@Inject

@Named("jcr:title")

@Optional

String title;

@ValueMapValue

String name;

@ValueMapValue(name="jcr:title",

optional=true)

String title;

Example: OSGi Service

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Generic Annotation Injector-specific Annotation

@Inject

SlingSettingsService settings;

@Inject

@Filter("(paths=/bin/something)")

List<Servlet> servlets;

@OSGiService

SlingSettingsService settings;

@OSGiService(

filter="(paths=/bin/something)")

List<Servlet> servlets;

Constructor Injection

Constructor Injection (since 1.1.0)

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Adds support for Constructor Injection in POJOs

Supports same features and annotations as field injection

Constructor Injection Example

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@Model(adaptables = Resource.class)

public class MyController {

@Inject

public MyController(

@Named("name") String name,

@ValueMapValue(name = "jcr:title", optional = true) String title,

@OSGiService SlingSettingsService settings) {

// initialization logic

}

}

Constructor Injection Hints

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@Inject is not placed on constructor arguments, but on constructor itself

Specifying a name for name-based injections is mandatory JDK does not support reading constructor

parameter names via reflection

New Injectors

New Injectors in 1.1.0

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Self Injector Sling Object Injector Resource Path Injector

Self Injector

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Injects the adaptable object itself Class-based injection

Or an object that can be adapted from it If the @Self annotation is present

Self Injector Example

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@Model(adaptables = Resource.class)

public class MyController {

// the adaptable itself

@Self

private Resource resource;

// an object that can be adapted from the Resource

@Self

private Product product;

// an object that can be adapted from the Resource

@Self

private ValueMap properties;

}

Sling Object Injector

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Injects commonly used sling objects Class-based injection

Supports Request, Response, Resource Resolver, Current Resource and Sling Script Helper

Sling Object Injector Example

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@Model(adaptables = SlingHttpServletRequest.class)

public class MyController {

@SlingObject

private Resource resource;

@SlingObject

private ResourceResolver resolver;

@SlingObject

private SlingHttpServletRequest request;

}

Sling Object Injector Hints

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For AEM Objects use AEM Object Injector e.g. Page, Page Manager, WCM Mode, Design Not part of Sling Models

Implementations http://wcm.io/sling/models/ or http://adobe-consulting-services.github.io/acs-aem-commons/

Resource Path Injector

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Injects a resource by its path@Model(adaptables = Resource.class)

public class MyController {

// injects resource from given path

@ResourcePath(path="/path/to/resource")

private Resource resource;

// injects resource from path that's stored in the "resourcePath" property

@ResourcePath(name="resourcePath")

private Resource otherResource;

}

Alternate Adapter Interfaces

Alternate Adapter Interfaces (since 1.1.0)

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Model implementations can be adapted to Interfaces they implement Like to OSGi SCR @Service annotation

If multiple models implement the same interface “ImplementationPicker” services can choose the right one

Alternate Adapter Interface Example

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@Model(adaptables = SlingHttpServletRequest.class,

adapters = ProductManager.class)

public class ProductManagerImpl implements ProductManager {

@AemObject

private ResourceResolver resolver;

@Override

public List<Product> listProducts() {

// business logic

}

}

Summing up

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All this new Sling Models Features allow a new architecture style for Sling Components and supporting business classes

More in the talk“Application architecture with Sling Models”

Resources

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Sling Models Documentationhttp://sling.apache.org/documentation/bundles/models.html

Sling Models 1.0.x Introduction by Justin Edelsonhttp://slideshare.net/justinedelson/sling-models-overview

Sling Models Content Packageshttps://github.com/Adobe-Consulting-Services/com.adobe.acs.bundles.sling-models/releases(Drop-in replacement in existing AEM6 instances, runs in CQ56 as well)

AEM Object Injector Implementationshttp://wcm.io/sling/models/http://adobe-consulting-services.github.io/acs-aem-commons/features/aem-sling-models-injectors.html

Application architecture with Sling Modelshttp://adapt.to/2014/en/schedule/sling-application-architecture-with-sling-models.html