Fiori Elements Extensions – When to use controller extensions vs. handlers?

[#1]

Hi everyone,

I’m currently working with Fiori elements applications and I’m trying to better understand the usage extensibility options:

• controller extensions

• event/extension handlers

What I think I understand so far:

• controller extensions seem to be more related to page lifecycle (onInit, onBeforeRendering, etc.) and manipulating generated controls

• handlers seem to be more related to user actions or specific control events (button press, validation, value help, etc.)

But there are still situations where the border is blurry for me.

I’m not just looking for definitions from documentation, but for experience-based explanations, examples, and best practices from people who use Fiori elements extensions in real projects.

Thanks in advance for any insights,

Mikolaj