Extending AEM Components Using sling:resourceSuperType — Powered by Sling Resource Merger

Quote's of the day
"You never fail until you stop trying"

What is Sling Resource Merger?

•  Sling Resource Merger is the hidden engine that makes AEM’s inheritance powerful.
• It allows developers to extend, reuse, and customize components efficiently — without touching the original ones.

⚙️ Where It Is Used in AEM

     Sling Resorce Merger works :

             When extending a component

                 a). What it is: Create a new component that inherits from an existing one.

               b). How it works:Use sling:resourceSuperType to point to the parent component.

               c). Key point: Only the parts you override (dialog, HTML) are changed; the rest                                 comes from the parent via Sling Resource Merger.

🧩 Purpose:

•  We have an existing component in our AEM project (not core, our own).
•  We found that our new component will use 80% of the same fields.
•  So, instead of copying everything, we decide to extend and customize it.

Note: Here, PersonalInfo is my existing component, and the existing fields are FirstName and SecondName.

Sling Model interface for the existing component.

Sling Model implementation class for the existing component.

This  is HTL file

Data is rendered for the existing component on the page.

Step 1:  Create a (PersonalInfoExtend) new Component & extend the existing component with                                       sling:resourceSuperType Property.

Step 2: Create a Sling Model interface for the PersonalInfoExtend component.

In this example, we have created an interface called PersonalInfoExtend inside the package

com.adobe.aem.guides.wknd.core.models.

Explanation

• The PersonalInfoExtend interface extends another interface called PersonalInfo.
• This means it inherits all methods from PersonalInfo.

• Along with the inherited methods, it also adds two new methods:

  • getAge() → to fetch or return the user’s age.

  • getSalary() → to fetch or return the user’s salary.

  This approach helps in reusing existing functionality (from PersonalInfo) and extending it with new fields without changing the original code.

Step 3: Create a Sling Model implement class for the PersonalInfoExtend component.

In this example, we’ve created a class called PersonalInfoExtendImpl inside the package

com.adobe.aem.guides.wknd.core.models.







Explanation 

• This class implements the interface PersonalInfoExtend — meaning it provides the actual logic (or data) for the methods defined in that interface.
• It also extends another class, PersonalInfoImpl, so it inherits all the existing properties and methods from it.

                  → This helps in reusing existing code instead of writing everything again.

Step 4: Create an HTL file for the PersonalInfoExtend component.

 

This is an authoring field on the page.

The extended component fetches and renders data on the page.

Thanks for Watching !!