AEM - Sling

[YaminiKolhe]

Hi @everyone,

In Adobe Experience Manager (AEM), when defining a Sling Model with the following adaptation:

@Model(adaptables = { Resource.class, SlingHttpServletRequest.class })

What is the purpose of still using the @Self annotation for fields such as:

@Self
private Resource resource;

@Self
private SlingHttpServletRequest request;

How does the @Self annotation interact with the @Model(adaptables) declaration, and what is the significance of using both in a Sling Model?

[tushaar_srivastava · Accepted solution]

Hi @YaminiKolhe 

You can go through including videos: http://www.sgaemsolutions.com/2017/08/deep-dive-on-sling-models-part-1.html 
https://satyamblogs.medium.com/sling-model-annotation-detailed-in-aem-4af0345d43ec 
https://taradevko.com/aem/sling-models-self-annotation/ 

Kindly go through all 3 links in detail and let's discuss any specific questions on it.

[YaminiKolhe]

@tushaar_srivastava Thank you for sharing such helpful information.

[tushaar_srivastava]

if that information solves your question do mark the above comment as correct reply, so that other can also get benefited!

Thanks for raising this important question

[PRATHYUSHA_VP]

Hi,

Please find the detailed explanation in below thread -

https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/what-is-diff-between-self-...

https://sling.apache.org/documentation/bundles/models.html#available-injectors

Hope this helps

Thanks

[YaminiKolhe]

@PRATHYUSHA_VP Thank you for sharing such helpful information.

[Jagadeesh_Prakash]

@YaminiKolhe 

Great question—this touches on a subtle but important aspect of how Sling Models resolve dependencies using annotations like @Model and @Self.

Purpose of @Model(adaptables = { ... })

@Model(adaptables = { Resource.class, SlingHttpServletRequest.class })

You're telling Sling Models that this class can be instantiated (adapted) from either a Resource or a SlingHttpServletRequest

So when code like this runs:

modelFactory.getModelFromWrappedRequest(request, MyModel.class);

or

resource.adaptTo(MyModel.class);

It will look for a matching adaptable type and attempt to inject the model.

What does @Self mean then?

The @Self annotation is used on fields or constructor parameters inside the model to inject the same object that was used to adapt the model.

For ex:

@Self
private Resource resource;

Here’s what this does:
- If the model was adapted from a Resource, resource will be injected with that same Resource.
- If the model was adapted from a SlingHttpServletRequest, the framework will try to get a Resource from the request (i.e., request.getResource()) and inject that.

Hope this is clear

[YaminiKolhe]

@Jagadeesh_Prakash Thank you